WO2015045393A1 - Nonaqueous electrolyte secondary battery - Google Patents

Nonaqueous electrolyte secondary battery Download PDF

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Publication number
WO2015045393A1
WO2015045393A1 PCT/JP2014/004917 JP2014004917W WO2015045393A1 WO 2015045393 A1 WO2015045393 A1 WO 2015045393A1 JP 2014004917 W JP2014004917 W JP 2014004917W WO 2015045393 A1 WO2015045393 A1 WO 2015045393A1
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Prior art keywords
substituent
substituted
group
unsaturated
secondary battery
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PCT/JP2014/004917
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French (fr)
Japanese (ja)
Inventor
山田 淳夫
裕貴 山田
佳浩 中垣
智之 河合
浩平 間瀬
雄紀 長谷川
三好 学
合田 信弘
佐々木 博之
武文 福本
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国立大学法人東京大学
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Priority claimed from JP2014186351A external-priority patent/JP5965444B2/en
Priority claimed from JP2014186352A external-priority patent/JP5967781B2/en
Application filed by 国立大学法人東京大学 filed Critical 国立大学法人東京大学
Priority to CN201480053188.4A priority Critical patent/CN105580192B/en
Priority to US15/024,654 priority patent/US20160240858A1/en
Priority to DE112014004443.1T priority patent/DE112014004443T5/en
Priority to KR1020167010618A priority patent/KR101901676B1/en
Publication of WO2015045393A1 publication Critical patent/WO2015045393A1/en
Priority to US15/993,729 priority patent/US20180277852A1/en

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    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01MPROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00Electrodes
    • H01M4/02Electrodes composed of, or comprising, active material
    • H01M4/13Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01MPROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00Secondary cells; Manufacture thereof
    • H01M10/05Accumulators with non-aqueous electrolyte
    • H01M10/052Li-accumulators
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01MPROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00Secondary cells; Manufacture thereof
    • H01M10/05Accumulators with non-aqueous electrolyte
    • H01M10/056Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
    • H01M10/0564Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
    • H01M10/0566Liquid materials
    • H01M10/0568Liquid materials characterised by the solutes
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01MPROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00Electrodes
    • H01M4/02Electrodes composed of, or comprising, active material
    • H01M4/62Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/621Binders
    • H01M4/622Binders being polymers
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01MPROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00Secondary cells; Manufacture thereof
    • H01M10/05Accumulators with non-aqueous electrolyte
    • H01M10/056Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
    • H01M10/0564Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
    • H01M10/0566Liquid materials
    • H01M10/0567Liquid materials characterised by the additives
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01MPROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00Secondary cells; Manufacture thereof
    • H01M10/05Accumulators with non-aqueous electrolyte
    • H01M10/056Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
    • H01M10/0564Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
    • H01M10/0566Liquid materials
    • H01M10/0569Liquid materials characterised by the solvents
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10Energy storage using batteries

Definitions

  • the present invention relates to a non-aqueous electrolyte secondary battery.
  • SEI Solid Electrolyte Interface
  • the SEI film on the negative electrode surface and the positive electrode surface allows passage of charge carriers such as lithium ions. Further, for example, the SEI film on the negative electrode surface exists between the negative electrode surface and the electrolytic solution, and is considered to contribute to further reduction and reduction of the electrolytic solution.
  • an SEI film is essential for a low potential negative electrode using graphite or Si-based negative electrode active material.
  • the discharge characteristics (hereinafter referred to as cycle characteristics) of the battery after the cycle has elapsed can be improved.
  • cycle characteristics discharge characteristics
  • the SEI film on the negative electrode surface and the positive electrode surface did not necessarily contribute to the improvement of the battery characteristics. Therefore, it is desired to develop a non-aqueous electrolyte secondary battery having an SEI film that can further improve battery characteristics.
  • a lithium ion secondary battery is a secondary battery that has a high charge / discharge capacity and can achieve high output.
  • Lithium ion secondary batteries are currently used mainly as power sources for portable electronic devices, notebook computers, and electric vehicles, and there is a demand for smaller and lighter secondary batteries.
  • a lithium ion secondary battery has an active material capable of inserting and extracting lithium (Li) in a positive electrode and a negative electrode, respectively. Then, the lithium ion moves in the electrolytic solution sealed between both electrodes.
  • the active material and binder used in the positive electrode and / or the negative electrode it is necessary to improve the active material and binder used in the positive electrode and / or the negative electrode, and improve the electrolytic solution.
  • a carbon material such as graphite is widely used in order to avoid the problem of dendrite precipitation.
  • a non-aqueous carbonate solvent such as a cyclic ester or a chain ester is used for a general electrolytic solution.
  • rate characteristics which are a kind of input / output characteristics of lithium ion secondary batteries.
  • Non-Patent Documents 1 to 3 a lithium ion secondary battery using a carbonate-based solvent such as ethylene carbonate or propylene carbonate has a large reaction resistance. For this reason, in order to improve the rate capacity characteristics, it is necessary to fundamentally review the solvent composition of the electrolytic solution.
  • the present invention has been made in view of the above circumstances, and an object to be solved is to obtain a non-aqueous electrolyte secondary battery having excellent battery characteristics.
  • SEI Solid Electrolyte Interface
  • the SEI film on the negative electrode surface and the positive electrode surface allows passage of charge carriers such as lithium ions. Further, for example, the SEI film on the negative electrode surface exists between the negative electrode surface and the electrolytic solution, and is considered to contribute to further reduction and reduction of the electrolytic solution.
  • an SEI film is essential for a low potential negative electrode using graphite or Si-based negative electrode active material.
  • the discharge characteristics (hereinafter referred to as cycle characteristics) of the battery after the cycle has elapsed can be improved.
  • cycle characteristics discharge characteristics
  • the SEI film on the negative electrode surface and the positive electrode surface did not necessarily contribute to the improvement of the battery characteristics. Therefore, it is desired to develop a non-aqueous electrolyte secondary battery having an SEI film that can further improve battery characteristics.
  • the inventors of the present invention have found that in conventional non-aqueous electrolyte secondary batteries, the passage of charge carriers such as lithium ions is not sufficient depending on the composition, structure, and thickness of the SEI film. It has been found that the film can cause an increase in reaction resistance (for example, a decrease in input / output characteristics) of the nonaqueous electrolyte secondary battery. Further research was conducted with the goal of developing a non-aqueous electrolyte secondary battery having an SEI film that can suppress the continuous decomposition of the electrolyte and also has excellent charge carrier permeability.
  • the nonaqueous electrolyte secondary battery (1) of the present invention that solves the above problems is Including a positive electrode, an electrolyte and a negative electrode
  • the electrolytic solution includes a salt containing an alkali metal, an alkaline earth metal or aluminum as a cation and containing a sulfur element and an oxygen element in the chemical structure of an anion, and an organic solvent having a hetero element, Regarding the peak intensity derived from the organic solvent in the vibrational spectrum of the electrolyte solution, when the intensity of the original peak of the organic solvent is Io and the intensity of the peak shifted from the peak is Is, Is> Io, An S, O-containing film having an S ⁇ O structure is formed on the surface of the negative electrode.
  • the nonaqueous electrolyte secondary battery (1) of the present invention that solves the above problems is Including a positive electrode, an electrolyte and a negative electrode
  • the electrolytic solution includes a salt containing an alkali metal, an alkaline earth metal or aluminum as a cation and containing a sulfur element and an oxygen element in the chemical structure of an anion, and an organic solvent having a hetero element, Regarding the peak intensity derived from the organic solvent in the vibrational spectrum of the electrolyte solution, when the intensity of the original peak of the organic solvent is Io and the intensity of the peak shifted from the peak is Is, Is> Io, An S, O-containing film having an S ⁇ O structure is formed on at least the positive electrode surface of the negative electrode surface and the positive electrode surface.
  • Such a nonaqueous electrolyte secondary battery (1) has an SEI film having a special structure on the negative electrode surface and / or the positive electrode surface, that is, an S, O-containing film, and is excellent in battery characteristics.
  • a general negative electrode is produced by applying a slurry containing a negative electrode active material and a binder to a current collector and drying it.
  • the binder has a role of binding between the negative electrode active materials and binding between the active material and the current collector, and a role of covering and protecting the negative electrode active material.
  • binders for negative electrodes include fluorine-containing polymers such as polyvinylidene fluoride (PVdF), water-soluble cellulose derivatives such as carboxymethyl cellulose (CMC), and polyacrylic acid.
  • PVdF polyvinylidene fluoride
  • CMC carboxymethyl cellulose
  • Patent Document 2 described above describes a negative electrode for a lithium ion secondary battery containing a polymer selected from the group consisting of polyacrylic acid and polymethacrylic acid, and the polymer includes an acid anhydride group.
  • Patent Document 3 described above describes that a polymer obtained by copolymerizing acrylic acid and methacrylic acid is used as a negative electrode binder or a positive electrode binder.
  • Patent Document 4 described above describes that a polymer obtained by copolymerizing acrylamide, acrylic acid and itaconic acid is used as a negative electrode binder or a positive electrode binder.
  • the feature of the nonaqueous electrolyte secondary battery (2) of the present invention that solves the above problems is as follows. Including a salt having alkali metal, alkaline earth metal or aluminum as a cation and an organic solvent having a hetero element, the peak intensity derived from the organic solvent in a vibrational spectrum is defined as Io. In the case where Is is the intensity of the peak where the peak is shifted, Is> Io, and a negative electrode having a negative electrode active material layer containing a binder composed of a polymer having a hydrophilic group. is there.
  • the nonaqueous electrolyte secondary battery (2) of the present invention uses a polymer having a hydrophilic group as a binder for a negative electrode, and uses the electrolytic solution of the present invention as an electrolytic solution.
  • a polymer such as polyvinylidene fluoride
  • a binder made of a polymer having a hydrophilic group as the negative electrode binder, it is possible to improve both the rate characteristics and the cycle characteristics.
  • non-aqueous electrolyte secondary battery is a lithium ion secondary battery
  • polar groups such as carboxyl groups contained in the binder attract lithium ions, so the concentration overvoltage becomes dominant. It is conceivable that the load characteristics are improved. Further, it is considered that the cycle characteristics are improved by the active material protecting action by the binder.
  • non-aqueous electrolyte secondary battery (2) it is possible to improve rate capacity characteristics and improve cycle characteristics by an optimal combination of the electrolytic solution and the binder.
  • the organic solvent contains a salt having alkali metal, alkaline earth metal or aluminum as a cation and an organic solvent having a hetero element, and the peak intensity derived from the organic solvent in a vibrational spectroscopic spectrum.
  • the “electrolytic solution with Is> Io” may be referred to as the “electrolytic solution of the present invention”.
  • those containing a sulfur element and an oxygen element in the chemical structure of the anion of the salt particularly “electrolytic solution (1)” or “electrolytic solution of the present invention (1)”.
  • the electrolytic solution (1) of the present invention is a kind of the electrolytic solution of the present invention, and is included in the nonaqueous electrolyte secondary battery (1).
  • the nonaqueous electrolyte secondary battery (2) may contain the electrolytic solution (1) of the present invention.
  • the nonaqueous electrolyte secondary battery (1) and the nonaqueous electrolyte secondary battery (2) are collectively referred to as the nonaqueous electrolyte secondary battery of the present invention.
  • the nonaqueous electrolyte secondary battery of the present invention is excellent in battery characteristics.
  • IR spectrum of the electrolyte solution E14 It is IR spectrum of the electrolyte solution E15. It is IR spectrum of the electrolyte solution C6. It is IR spectrum of dimethyl carbonate. It is IR spectrum of the electrolyte solution E16. It is IR spectrum of the electrolyte solution E17. It is IR spectrum of the electrolyte solution E18. It is IR spectrum of the electrolyte solution C7. It is IR spectrum of ethyl methyl carbonate. It is IR spectrum of the electrolyte solution E19. It is IR spectrum of the electrolyte solution E20. It is IR spectrum of the electrolyte solution E21. It is IR spectrum of the electrolyte solution C8.
  • FIG. 10 is an XPS analysis result of carbon elements of negative electrode S and O-containing coatings of Example 1-1, Example 1-2, and Comparative Example 1-1 in Evaluation Example 12.
  • FIG. 7 shows the results of XPS analysis of fluorine elements in negative electrode S and O-containing films of Example 1-1, Example 1-2, and Comparative Example 1-1 in Evaluation Example 12.
  • 7 is an XPS analysis result of nitrogen element in negative electrode S, O-containing coatings of Example 1-1, Example 1-2, and Comparative Example 1-1 in Evaluation Example 12.
  • 7 is an XPS analysis result of oxygen elements in negative electrode S and O-containing films of Example 1-1, Example 1-2, and Comparative Example 1-1 in Evaluation Example 12.
  • FIG. 7 shows the results of XPS analysis result of fluorine elements in negative electrode S and O-containing films of Example 1-1, Example 1-2, and Comparative Example 1-1 in Evaluation Example 12.
  • 7 is an XPS analysis result of nitrogen element in negative electrode S, O-containing coatings of Example 1-1, Example 1-2, and Comparative Example
  • FIG. 10 shows the XPS analysis results for sulfur element in the negative electrode S, O-containing coatings of Example 1-1, Example 1-2, and Comparative Example 1-1 in Evaluation Example 12.
  • FIG. 10 is an XPS analysis result of a negative electrode S, O-containing film of Example 1-1 in Evaluation Example 12.
  • 7 is an XPS analysis result of a negative electrode S, O-containing film of Example 1-2 in Evaluation Example 12.
  • 14 is a BF-STEM image of a negative electrode S, O-containing film of Example 1-1 in Evaluation Example 12.
  • 14 is a STEM analysis result on C of the negative electrode S, O-containing film of Example 1-1 in Evaluation Example 12.
  • FIG. 10 shows STEM analysis results for O of the negative electrode S, O-containing film of Example 1-1 in Evaluation Example 12.
  • FIG. 10 shows STEM analysis results for S of the negative electrode S, O-containing film of Example 1-1 in Evaluation Example 12.
  • FIG. 10 is an XPS analysis result on O of the positive electrode S, O-containing film of Example 1-1 in Evaluation Example 12.
  • 7 is an XPS analysis result for S of the positive electrode S, O-containing film of Example 1-1 in Evaluation Example 12.
  • 7 is an XPS analysis result for S of the positive electrode S, O-containing film of Example 1-4 in Evaluation Example 12.
  • 7 is an XPS analysis result for O of the positive electrode S, O-containing film of Example 1-4 in Evaluation Example 12.
  • FIG. 10 shows the XPS analysis results for S of the positive electrode S and O-containing coatings of Example 1-4, Example 1-5, and Comparative Example 1-2 in Evaluation Example 12.
  • FIG. 10 shows the XPS analysis results for S of the positive electrode S and O-containing coatings of Example 1-4, Example 1-5, and Comparative Example 1-2 in Evaluation Example 12.
  • FIG. 10 shows the analysis results of O in the negative electrode S and O-containing coatings of Example 1-4, Example 1-5, and Comparative Example 1-2 in Evaluation Example 12.
  • FIG. 7 shows the analysis results for O in the negative electrode S, O-containing coatings of Example 1-6, Example 1-7, and Comparative Example 1-3 in Evaluation Example 12. It is a complex impedance plane plot of the battery in the evaluation example 13.
  • 14 is a DSC chart of the nonaqueous electrolyte secondary battery of Example 1-1 in Evaluation Example 20.
  • 18 is a DSC chart of the nonaqueous electrolyte secondary battery in Comparative Example 1-1 in Evaluation Example 20. It is a graph which shows the relationship between the electric current of EB4 in evaluation example 21, and electrode potential.
  • 22 is a graph showing a relationship between a potential (3.1 to 4.6 V) with respect to EB4 and a response current in Evaluation Example 22.
  • 14 is a graph showing a relationship between a potential (3.1 to 5.1 V) and a response current with respect to EB4 in Evaluation Example 22.
  • 14 is a graph showing a relationship between a potential (3.1 to 4.6 V) with respect to EB5 and a response current in Evaluation Example 22.
  • 14 is a graph showing a relationship between a potential (3.1 to 5.1 V) with respect to EB5 and a response current in Evaluation Example 22.
  • 22 is a graph showing a relationship between a potential (3.1 to 4.6 V) with respect to EB6 and a response current in Evaluation Example 22.
  • FIG. 22 is a graph showing a relationship between a potential (3.1 to 5.1 V) with respect to EB6 and a response current in Evaluation Example 22.
  • 14 is a graph showing a relationship between a potential (3.1 to 4.6 V) with respect to EB7 and a response current in Evaluation Example 22.
  • 14 is a graph showing a relationship between a potential (3.1 to 5.1 V) and a response current with respect to EB7 in Evaluation Example 22.
  • 14 is a graph showing a relationship between a potential (3.1 to 4.6 V) and response current with respect to CB4 in Evaluation Example 22.
  • 14 is a graph showing a relationship between a potential (3.0 to 4.5 V) with respect to EB5 and a response current in Evaluation Example 22.
  • 73 is obtained by changing the scale of the vertical axis in FIG. 14 is a graph showing a relationship between a potential (3.0 to 5.0 V) with respect to EB5 and a response current in Evaluation Example 22.
  • 74 is obtained by changing the scale of the vertical axis in FIG. 14 is a graph showing a relationship between a potential (3.0 to 4.5 V) with respect to EB8 and a response current in Evaluation Example 22.
  • 14 is a graph showing a relationship between a potential (3.0 to 5.0 V) with respect to EB8 and a response current in Evaluation Example 22.
  • 14 is a graph showing a relationship between a potential (3.0 to 4.5 V) and a response current with respect to CB5 in Evaluation Example 22.
  • FIG. 14 is a graph showing a relationship between a potential (3.0 to 5.0 V) and a response current with respect to CB5 in Evaluation Example 22.
  • 18 is a surface analysis result of an aluminum foil after charging and discharging of the nonaqueous electrolyte secondary battery of Example 1-1 in Evaluation Example 24. 18 shows the surface analysis results of the aluminum foil after charge / discharge of the nonaqueous electrolyte secondary battery of Example 1-2 in Evaluation Example 24. It is a charging / discharging curve of EB9. It is a charging / discharging curve of EB10. It is a charging / discharging curve of EB11. It is a charging / discharging curve of EB12. It is a charging / discharging curve of CB6.
  • the numerical range “a to b” described in this specification includes the lower limit “a” and the upper limit “b”.
  • the numerical range can be configured by arbitrarily combining these upper limit value and lower limit value and the numerical values listed in the examples.
  • numerical values arbitrarily selected from the numerical value range can be used as upper and lower numerical values.
  • the nonaqueous electrolyte secondary battery (1) of the present invention includes a negative electrode, a positive electrode, and the electrolytic solution (1) of the present invention, and an S, O-containing film is formed on the surface of the positive electrode and / or the negative electrode. It is.
  • the nonaqueous electrolyte secondary battery (2) of the present invention includes the electrolytic solution of the present invention and a negative electrode having a negative electrode active material layer containing a binder made of a polymer having a hydrophilic group.
  • the nonaqueous electrolyte secondary battery (1) of the present invention is intended to improve battery characteristics by forming an S, O-containing film on the surface of the positive electrode and / or the negative electrode. Therefore, in the nonaqueous electrolyte secondary battery (1), battery constituent elements other than the electrolyte, such as a negative electrode active material, a positive electrode active material, a conductive additive, a binder, a current collector, and a separator, are not particularly limited.
  • the nonaqueous electrolyte secondary battery (2) of the present invention is intended to improve battery characteristics by an optimal combination of a negative electrode binder and an electrolytic solution.
  • the non-aqueous electrolyte secondary battery (2) battery constituent elements other than the negative electrode binder and the electrolytic solution are not particularly limited.
  • an S, O-containing film which is a SEI film having a special structure, is formed on the negative electrode surface and / or the positive electrode surface in the nonaqueous electrolyte secondary battery of the present invention.
  • the charge carrier in the nonaqueous electrolyte secondary battery of the present invention is not particularly limited.
  • the nonaqueous electrolyte secondary battery of the present invention may be a nonaqueous electrolyte secondary battery using lithium as a charge carrier (for example, a lithium secondary battery or a lithium ion secondary battery), or sodium as a charge carrier. It may be a non-aqueous electrolyte secondary battery (for example, a sodium secondary battery or a sodium ion secondary battery).
  • the electrolytic solution of the present invention contains a salt having a cation of alkali metal, alkaline earth metal or aluminum as a cation and an organic solvent having a hetero atom, and the organic solvent has a peak intensity derived from the organic solvent in the vibrational spectrum.
  • the intensity of the original peak is Io
  • the intensity of the peak obtained by wave number shifting of the original peak of the organic solvent is Is, Is> Io.
  • the electrolyte solution (1) used for the nonaqueous electrolyte secondary battery (1) has an alkali metal, alkaline earth metal, or aluminum as a cation as a salt and a chemical structure of an anion with elemental sulfur and oxygen.
  • a salt containing an element is used.
  • the electrolytic solution (1) is an embodiment of the electrolytic solution of the present invention. Therefore, in the electrolytic solution of the present invention, the relationship between Io and Is is always Is> Io. On the other hand, in the conventional electrolytic solution, the relationship between Is and Io is Is ⁇ Io. In this respect, the electrolytic solution of the present invention is greatly different from the conventional electrolytic solution.
  • a salt contained in the electrolytic solution and / or electrolytic solution (1) of the present invention that is, a “salt having an alkali metal, alkaline earth metal or aluminum as a cation” and / or “alkaline metal
  • a salt containing an alkaline earth metal or aluminum as a cation and containing an element of sulfur and oxygen in the chemical structure of the anion may be referred to as a “metal salt”, a supporting salt, a supporting electrolyte, or simply “salt”.
  • electrolyte solution (1) is one form of the electrolyte solution of the present invention
  • the portion describing “electrolyte solution of the present invention” without any particular explanation is the present invention including electrolyte solution (1). It is assumed that the general electrolyte solution is described.
  • the metal salt in the electrolytic solution of the present invention may be a compound that is usually used as an electrolyte such as LiClO 4 , LiAsF 6 , LiPF 6 , LiBF 4 , LiAlCl 4 , etc. contained in the electrolytic solution of the battery.
  • the cation of the metal salt include alkali metals such as lithium, sodium and potassium, alkaline earth metals such as beryllium, magnesium, calcium, strontium and barium, and aluminum.
  • the cation of the metal salt is preferably the same metal ion as the charge carrier of the battery using the electrolytic solution.
  • the metal salt cation is preferably lithium.
  • the chemical structure of the anion of the salt may contain at least one element selected from halogen, boron, nitrogen, oxygen, sulfur or carbon.
  • Specific examples of the chemical structure of an anion containing halogen or boron include ClO 4 , PF 6 , AsF 6 , SbF 6 , TaF 6 , BF 4 , SiF 6 , B (C 6 H 5 ) 4 , and B (oxalate). 2 , Cl, Br, and I.
  • the chemical structure of the anion of the salt is preferably a chemical structure represented by the following general formula (1), general formula (2), or general formula (3).
  • R 1 is hydrogen, halogen, an alkyl group which may be substituted with a substituent, a cycloalkyl group which may be substituted with a substituent, an unsaturated alkyl group which may be substituted with a substituent, or a substituent.
  • An unsaturated alkoxy group that may be substituted with a substituent, a thioalkoxy group that may be substituted with a substituent, an unsaturated thioalkoxy group that may be substituted with a substituent, CN, SCN, or OCN Is done.
  • R 2 represents hydrogen, halogen, an alkyl group which may be substituted with a substituent, a cycloalkyl group which may be substituted with a substituent, an unsaturated alkyl group which may be substituted with a substituent, or a substituent.
  • R 1 and R 2 may be bonded to each other to form a ring.
  • X 2 is, SO 2
  • R a , R b , R c , and R d are each independently hydrogen, halogen, an alkyl group that may be substituted with a substituent, a cycloalkyl group that may be substituted with a substituent, or a substituent.
  • R a , R b , R c , and R d may combine with R 1 or R 2 to form a ring.
  • R 3 X 3 Y General formula (2) (R 3 is hydrogen, halogen, an alkyl group which may be substituted with a substituent, a cycloalkyl group which may be substituted with a substituent, an unsaturated alkyl group which may be substituted with a substituent, or a substituent.
  • An unsaturated alkoxy group that may be substituted with a substituent, a thioalkoxy group that may be substituted with a substituent, an unsaturated thioalkoxy group that may be substituted with a substituent, CN, SCN, or OCN Is done.
  • R e and R f are each independently hydrogen, halogen, an alkyl group that may be substituted with a substituent, a cycloalkyl group that may be substituted with a substituent, or a group that may be substituted with a substituent.
  • R e and R f may combine with R 3 to form a ring.
  • Y is selected from O and S.
  • R 4 is hydrogen, halogen, an alkyl group which may be substituted with a substituent, a cycloalkyl group which may be substituted with a substituent, an unsaturated alkyl group which may be substituted with a substituent, or a substituent.
  • An unsaturated alkoxy group that may be substituted with a substituent, a thioalkoxy group that may be substituted with a substituent, an unsaturated thioalkoxy group that may be substituted with a substituent, CN, SCN, or OCN Is done.
  • R 5 represents hydrogen, halogen, an alkyl group which may be substituted with a substituent, a cycloalkyl group which may be substituted with a substituent, an unsaturated alkyl group which may be substituted with a substituent, or a substituent.
  • the R 6 is hydrogen, halogen, an alkyl group which may be substituted with a substituent, a cycloalkyl group which may be substituted with a substituent, an unsaturated alkyl group which may be substituted with a substituent, or a substituent.
  • any two or three of R 4 , R 5 and R 6 may be bonded to form a ring.
  • R g , R h , R i , R j , R k , and R l are each independently hydrogen, halogen, an alkyl group that may be substituted with a substituent, or a cycloalkyl that may be substituted with a substituent.
  • an unsaturated alkyl group that may be substituted with a substituent an unsaturated cycloalkyl group that may be substituted with a substituent, an aromatic group that may be substituted with a substituent, or a substituent that is substituted with a substituent
  • R g , R h , R i , R j , R k , and R l may combine with R 4 , R 5, or R 6 to form a ring.
  • substituents in the phrase “may be substituted with a substituent” include an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, an unsaturated cycloalkyl group, an aromatic group, a heterocyclic group, a halogen, and OH.
  • the chemical structure of the salt anion is more preferably a chemical structure represented by the following general formula (4), general formula (5), or general formula (6).
  • R 7 and R 8 are each independently C n H a F b Cl c Br d I e (CN) f (SCN) g (OCN) h .
  • R m , R n , R o , and R p are each independently substituted with hydrogen, halogen, an alkyl group that may be substituted with a substituent, a cycloalkyl group that may be substituted with a substituent, or a substituent.
  • R m , R n , R o , and R p may combine with R 7 or R 8 to form a ring.
  • R q and R r are each independently hydrogen, halogen, an alkyl group that may be substituted with a substituent, a cycloalkyl group that may be substituted with a substituent, or a group that may be substituted with a substituent.
  • R q and R r may combine with R 9 to form a ring.
  • Y is selected from O and S.
  • R 10 X 10 (R 11 X 11 ) (R 12 X 12 ) C ...
  • R 10 , R 11 , and R 12 are each independently C n H a F b Cl c Br d I e (CN) f (SCN) g (OCN) h .
  • R s , R t , R u , R v , R w , and R x are each independently hydrogen, halogen, an alkyl group that may be substituted with a substituent, or a cycloalkyl that may be substituted with a substituent.
  • an unsaturated alkyl group that may be substituted with a substituent an unsaturated cycloalkyl group that may be substituted with a substituent, an aromatic group that may be substituted with a substituent, or a substituent that is substituted with a substituent
  • R s , R t , R u , R v , R w , and R x may combine with R 10 , R 11, or R 12 to form a ring.
  • n is preferably an integer of 0 to 6, more preferably an integer of 0 to 4, and particularly preferably an integer of 0 to 2.
  • n is preferably an integer of 1 to 8, more preferably an integer of 1 to 7, and particularly preferably an integer of 1 to 3.
  • the chemical structure of the salt anion is more preferably represented by the following general formula (7), general formula (8) or general formula (9).
  • R 13 SO 2 (R 14 SO 2 ) N...
  • R 13 and R 14 are each independently C n H a F b Cl c Br d I e .
  • R 15 SO 3 ...
  • R 15 is a C n H a F b Cl c Br d I e.
  • R 16 SO 2 (R 17 SO 2 ) (R 18 SO 2 ) C General formula (9)
  • R 16 , R 17 , and R 18 are each independently C n H a F b Cl c Br d I e .
  • n is preferably an integer of 0 to 6, more preferably an integer of 0 to 4, and particularly preferably an integer of 0 to 2.
  • n is preferably an integer of 1 to 8, more preferably an integer of 1 to 7, and particularly preferably an integer of 1 to 3.
  • the metal salt is (CF 3 SO 2 ) 2 NLi (hereinafter sometimes referred to as “LiTFSA”), (FSO 2 ) 2 NLi (hereinafter sometimes referred to as “LiFSA”), (C 2 F 5 SO 2 ) 2 NLi, FSO 2 (CF 3 SO 2 ) NLi, (SO 2 CF 2 CF 2 SO 2 ) NLi, (SO 2 CF 2 CF 2 SO 2 ) NLi, FSO 2 (CH 3 SO 2 ) NLi FSO 2 (C 2 F 5 SO 2 ) NLi or FSO 2 (C 2 H 5 SO 2 ) NLi is particularly preferred.
  • These metal salts are imide salts. Therefore, it can be said that it is particularly preferable to use an imide salt as the metal salt.
  • the metal salt may be a combination of an appropriate number of cations and anions described above.
  • One kind of metal salt may be adopted, or a plurality of kinds may be used in combination.
  • the metal salt in the electrolytic solution (1) contains a sulfur element and an oxygen element in the chemical structure of the anion, and the cation of the metal salt is the same as that of the above-described electrolytic solution of the present invention.
  • the chemical structure of the anion of the salt in the electrolytic solution (1) contains sulfur element and oxygen element.
  • the chemical structure of this anion will be specifically described below.
  • the electrolytic solution (1) is the same as the electrolytic solution of the present invention.
  • the chemical structure of the anion of the salt is preferably a chemical structure represented by the above general formula (1), general formula (2), or general formula (3), but X 1 to X 5 are as described above.
  • the X 1 to X 5 are more limited.
  • X 1 in the general formula (1) is selected from SO 2
  • S O
  • X 2 is selected from SO 2
  • S O.
  • X 3 in the general formula (2) is selected from SO 2 and S ⁇ O.
  • X 4 in the general formula (3) is selected from SO 2
  • S O
  • X 5 is selected from SO 2
  • S O
  • X 6 is SO 2
  • S O is selected.
  • the chemical structure of the anion of the salt is more preferably a chemical structure represented by the above general formula (4), general formula (5), or general formula (6), but X 7 to X 12 are as follows. More limited than the above X 7 to X 12 .
  • X 7 in the general formula (4) is selected from SO 2
  • S O
  • X 8 is selected from SO 2
  • S O.
  • X 9 in the general formula (5) is selected from SO 2 and S ⁇ O.
  • X 10 in the general formula (6) is selected from SO 2
  • S O
  • X 11 is selected from SO 2
  • S O
  • X 12 is SO 2
  • S O.
  • Organic solvent having a hetero element an organic solvent in which the hetero element is at least one selected from nitrogen, oxygen, sulfur and halogen is preferable, and an organic solvent in which the hetero element is at least one selected from nitrogen or oxygen Is more preferable.
  • an aprotic solvent having no proton donating group such as NH group, NH 2 group, OH group, and SH group is preferable.
  • organic solvent having a hetero element examples include nitriles such as acetonitrile, propionitrile, acrylonitrile, malononitrile, 1,2-dimethoxyethane, 1, 2-diethoxyethane, tetrahydrofuran, 1,2-dioxane, 1,3-dioxane, 1,4-dioxane, 2,2-dimethyl-1,3-dioxolane, 2-methyltetrahydropyran, 2-methyltetrahydrofuran, crown Ethers such as ether, carbonates such as ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, and ethylmethyl carbonate, formamide, N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolide Amides such as isopropyl isocyanate, n-propyl isocyanate, chloromethyl
  • Esters glycidyl methyl ether, epoxy butane, epoxy such as 2-ethyloxirane, oxazole, 2-ethyloxazole, oxazoline, oxazole such as 2-methyl-2-oxazoline, ketone such as acetone, methyl ethyl ketone, methyl isobutyl ketone Acid anhydrides such as acetic anhydride and propionic anhydride, sulfones such as dimethyl sulfone and sulfolane, sulfoxides such as dimethyl sulfoxide, 1-nitropropane and 2-nitrate Nitros such as propane, furans such as furan and furfural, cyclic esters such as ⁇ -butyrolactone, ⁇ -valerolactone and ⁇ -valerolactone, aromatic heterocycles such as thiophene and pyridine, tetrahydro-4-pyrone, Examples thereof include heterocyclic rings such as 1-methylpyr
  • examples of the organic solvent having a hetero element may include a chain carbonate represented by the following general formula (10).
  • n is preferably an integer of 1 to 6, more preferably an integer of 1 to 4, and particularly preferably an integer of 1 to 2.
  • m is preferably an integer of 3 to 8, more preferably an integer of 4 to 7, and particularly preferably an integer of 5 to 6.
  • DMC dimethyl carbonate
  • DEC diethyl carbonate
  • EMC ethylmethyl Carbonate
  • a solvent having a relative dielectric constant of 20 or more or a donor ether oxygen is preferable.
  • organic solvent include nitriles such as acetonitrile, propionitrile, acrylonitrile, and malononitrile, 2-dimethoxyethane, 1,2-diethoxyethane, tetrahydrofuran, 1,2-dioxane, 1,3-dioxane, 1,4-dioxane, 2,2-dimethyl-1,3-dioxolane, 2-methyltetrahydropyran And ethers such as 2-methyltetrahydrofuran and crown ether, N, N-dimethylformamide, acetone, dimethyl sulfoxide, and sulfolane.
  • acetonitrile hereinafter sometimes referred to as “AN”
  • DM 1, 2-dimethoxyethane
  • the peak intensity derived from the organic solvent contained in the electrolyte solution is denoted by Io, and the peak of the organic solvent inherent peak is shifted (hereinafter, “ If the intensity of “shift peak” is sometimes referred to as “Is”, Is> Io. That is, in the vibrational spectral spectrum chart obtained by subjecting the electrolytic solution of the present invention to vibrational spectral measurement, the relationship between the two peak intensities is Is> Io.
  • the original peak of the organic solvent means a peak observed at the peak position (wave number) when vibration spectroscopy measurement is performed only on the organic solvent.
  • the value of the intensity Io of the original peak of the organic solvent and the value of the intensity Is of the shift peak are the height or area from the baseline of each peak in the vibrational spectrum.
  • the relationship when there are a plurality of peaks in which the original peak of the organic solvent is shifted, the relationship may be determined based on the peak from which the relationship between Is and Io is most easily determined.
  • an organic solvent that can determine the relationship between Is and Io most easily is selected, an organic solvent that can determine the relationship between Is and Io most easily (the difference between Is and Io is most pronounced) is selected, The relationship between Is and Io may be determined based on the peak intensity. If the peak shift amount is small and the peaks before and after the shift appear to be a gentle mountain, peak separation may be performed using known means to determine the relationship between Is and Io.
  • the peak of an organic solvent that is most easily coordinated with a cation (hereinafter sometimes referred to as “preferred coordination solvent”) is another. Shift in preference to.
  • the mass% of the preferential coordination solvent with respect to the entire organic solvent having a hetero element is preferably 40% or more, more preferably 50% or more, and further preferably 60% or more. 80% or more is particularly preferable.
  • the volume% of the preferential coordination solvent with respect to the entire organic solvent having a hetero element is preferably 40% or more, more preferably 50% or more, and 60% or more. Is more preferable, and 80% or more is particularly preferable.
  • the relationship between the two peak intensities in the vibrational spectrum of the electrolytic solution of the present invention preferably satisfies the condition of Is> 2 ⁇ Io, more preferably satisfies the condition of Is> 3 ⁇ Io, and Is> 5 ⁇ It is more preferable that the condition of Io is satisfied, and it is particularly preferable that the condition of Is> 7 ⁇ Io is satisfied.
  • Most preferred is an electrolytic solution in which the intensity Io of the peak inherent in the organic solvent is not observed and the intensity Is of the shift peak is observed in the vibrational spectrum of the electrolytic solution of the present invention. In the electrolytic solution, it means that all the molecules of the organic solvent contained in the electrolytic solution are completely solvated with the metal salt.
  • the metal salt and the organic solvent (or preferential coordination solvent) having a hetero element have an interaction.
  • a metal salt and a hetero element of an organic solvent (or preferential coordination solvent) having a hetero element form a coordination bond
  • the organic solvent (or preferential coordinating solvent) having a metal salt and a hetero element ) Is estimated to form a stable cluster. From the results of Examples described later, this cluster is presumed to be formed by coordination of two molecules of an organic solvent (or preferential coordination solvent) having a hetero element with one molecule of a metal salt.
  • the molar range of the organic solvent having a hetero element (or preferential coordination solvent) with respect to 1 mol of the metal salt in the electrolytic solution of the present invention is preferably 1.4 mol or more and less than 3.5 mol. More preferably, it is 0.5 mol or more and 3.1 mol or less, and 1.6 mol or more and 3 mol or less are still more preferable.
  • the electrolytic solution of the present invention it is presumed that a cluster is formed by coordination of two molecules of an organic solvent (or a preferential coordination solvent) having a hetero element with one molecule of a metal salt.
  • concentration (mol / L) of the electrolytic solution of the invention depends on the molecular weight of each of the metal salt and the organic solvent and the density when the solution is used. Therefore, it is not appropriate to prescribe the concentration of the electrolytic solution of the present invention.
  • Table 1 individually illustrates the concentration (mol / L) of the electrolytic solution of the present invention.
  • the organic solvent that forms the cluster and the organic solvent that is not involved in the formation of the cluster have different environments. Therefore, in vibrational spectroscopy measurement, the peak derived from the organic solvent forming the cluster is higher than the observed wave number of the peak derived from the organic solvent not involved in the cluster formation (original peak of the organic solvent). Or it is observed shifted to the low wavenumber side. That is, the shift peak corresponds to the peak of the organic solvent forming the cluster.
  • an IR spectrum or a Raman spectrum can be exemplified.
  • the measurement method for IR measurement include transmission measurement methods such as Nujol method and liquid film method, and reflection measurement methods such as ATR method.
  • transmission measurement methods such as Nujol method and liquid film method
  • reflection measurement methods such as ATR method.
  • the vibrational spectroscopic measurement is preferably performed under conditions that can reduce or ignore the influence of moisture in the atmosphere.
  • IR measurement may be performed under low humidity or no humidity conditions such as in a dry room or a glove box, or Raman measurement may be performed with the electrolyte in a sealed container.
  • LiTFSA is dissolved in an acetonitrile solvent at a concentration of 1 mol / L to obtain an electrolytic solution according to conventional technical common sense. Since 1 L of acetonitrile corresponds to about 19 mol, 1 L of conventional electrolyte includes 1 mol of LiTFSA and 19 mol of acetonitrile. Then, in the conventional electrolyte, there are many acetonitriles that are not solvated with LiTFSA (not coordinated with Li) simultaneously with acetonitrile that is solvated with LiTFSA (coordinated with Li). .
  • the acetonitrile molecule is different between the LiTFSA solvated acetonitrile molecule and the LiTFSA non-solvated acetonitrile molecule, in the IR spectrum, the acetonitrile peaks of both are distinguished and observed. Is done. More specifically, the peak of acetonitrile that is not solvated with LiTFSA is observed at the same position (wave number) as in the case of IR measurement of only acetonitrile, but the peak of acetonitrile that is solvated with LiTFSA. Is observed with the peak position (wave number) shifted to the high wave number side.
  • the electrolytic solution of the present invention has a higher LiTFSA concentration than the conventional electrolytic solution, and the number of acetonitrile molecules solvated with LiTFSA (forming clusters) in the electrolytic solution is different from that of LiTFSA. More than the number of unsolvated acetonitrile molecules. Then, the relation between the intensity Io of the original peak of the acetonitrile and the intensity Is of the peak obtained by shifting the original peak of acetonitrile in the vibrational spectrum of the electrolytic solution of the present invention is Is> Io.
  • Table 2 exemplifies the wave numbers of organic solvents that are considered useful for the calculation of Io and Is and their attribution in the vibrational spectrum of the electrolytic solution of the present invention. It should be added that the wave number of the observed peak may be different from the following wave numbers depending on the measurement apparatus, measurement environment, and measurement conditions of the vibrational spectrum.
  • the electrolytic solution of the present invention is different from the conventional electrolytic solution in that the presence environment of the metal salt and the organic solvent is different and the concentration of the metal salt is high, so that the metal ion transport rate in the electrolytic solution is improved (especially metal When Li is lithium, the lithium transport number is improved), the reaction rate between the electrode and the electrolyte solution is improved, the uneven distribution of the salt concentration of the electrolyte solution that occurs during high-rate charge / discharge of the battery, and the electric double layer capacity can be expected to increase .
  • the SEI film having a special structure derived from the electrolytic solution of the present invention and formed on the surface of the negative electrode and / or the positive electrode.
  • the method for producing the electrolytic solution of the present invention will be described. Since the electrolytic solution of the present invention has a higher metal salt content than the conventional electrolytic solution, the production method in which an organic solvent is added to a solid (powder) metal salt results in the formation of aggregates. It is difficult to produce an electrolytic solution. Therefore, in the manufacturing method of the electrolyte solution of this invention, it is preferable to manufacture, adding a metal salt gradually with respect to an organic solvent, and maintaining the solution state of electrolyte solution.
  • the electrolytic solution of the present invention includes a liquid in which the metal salt is dissolved in the organic solvent beyond the conventionally considered saturation solubility.
  • a method for producing an electrolytic solution of the present invention includes a first dissolving step of preparing a first electrolytic solution by mixing an organic solvent having a hetero element and a metal salt, dissolving the metal salt, stirring and / or Alternatively, under heating conditions, the metal salt is added to the first electrolyte solution, the metal salt is dissolved, and a second electrolyte solution in a supersaturated state is prepared; and stirring and / or heating conditions, A third dissolving step of adding the metal salt to the second electrolytic solution, dissolving the metal salt, and preparing a third electrolytic solution;
  • the “supersaturated state” refers to a state in which metal salt crystals are precipitated from the electrolyte when the stirring and / or heating conditions are canceled or when crystal nucleation energy such as vibration is applied. Means.
  • the second electrolytic solution is “supersaturated”, and the first electrolytic solution and the third electrolytic solution are not “supersaturated”.
  • the above-described method for producing the electrolytic solution of the present invention is a thermodynamically stable liquid state, and passes through the first electrolytic solution containing the conventional metal salt concentration, and then the thermodynamically unstable liquid state.
  • the second electrolytic solution passes through the two electrolytic solutions and becomes a thermodynamically stable new electrolytic third solution, that is, the electrolytic solution of the present invention.
  • the third electrolyte solution is composed of, for example, two molecules of an organic solvent for one lithium salt molecule, and a strong distribution between these molecules. It is presumed that the cluster stabilized by the coordinate bond inhibits the crystallization of the lithium salt.
  • the first dissolution step is a step of preparing a first electrolytic solution by mixing an organic solvent having a hetero atom and a metal salt to dissolve the metal salt.
  • a metal salt may be added to the organic solvent having a heteroatom, or an organic solvent having a heteroatom may be added to the metal salt.
  • the first dissolution step is preferably performed under stirring and / or heating conditions. What is necessary is just to set suitably about stirring speed. About heating conditions, it is preferable to control suitably with thermostats, such as a water bath or an oil bath. Since heat of dissolution is generated when the metal salt is dissolved, it is preferable to strictly control the temperature condition when using a metal salt that is unstable to heat. In addition, the organic solvent may be cooled in advance, or the first dissolution step may be performed under cooling conditions.
  • the first dissolution step and the second dissolution step may be performed continuously, or the first electrolytic solution obtained in the first dissolution step is temporarily stored (standing), and after a certain time has passed, You may implement a melt
  • the second dissolution step is a step of preparing a supersaturated second electrolyte solution by adding a metal salt to the first electrolyte solution under stirring and / or heating conditions to dissolve the metal salt.
  • the stirring condition may be achieved, or the second dissolution step is performed using a stirrer and a device (stirrer) that operates the stirrer.
  • the stirring condition may be used.
  • Heating conditions it is preferable to control suitably with thermostats, such as a water bath or an oil bath.
  • thermostats such as a water bath or an oil bath.
  • heating here refers to warming a target object to temperature more than normal temperature (25 degreeC).
  • the heating temperature is more preferably 30 ° C. or higher, and further preferably 35 ° C. or higher. Further, the heating temperature is preferably lower than the boiling point of the organic solvent.
  • the added metal salt is not sufficiently dissolved, increase the stirring speed and / or further heating.
  • a small amount of an organic solvent having a hetero atom may be added to the electrolytic solution in the second dissolution step.
  • the second dissolution step and the third dissolution step are preferably carried out continuously.
  • the third dissolution step is a step of preparing a third electrolyte solution by adding a metal salt to the second electrolyte solution under stirring and / or heating conditions to dissolve the metal salt.
  • it is necessary to add a metal salt to the supersaturated second electrolytic solution and dissolve it. Therefore, it is essential to perform the stirring and / or heating conditions as in the second dissolution step. Specific stirring and / or heating conditions are the same as those in the second dissolution step.
  • the electrolytic solution of the present invention is composed of, for example, two molecules of an organic solvent for one molecule of a lithium salt, and is presumed to form a cluster stabilized by a strong coordinate bond between these molecules. Is done.
  • the first to third dissolving steps can be performed even if the supersaturated state is not passed at the treatment temperature in each dissolving step.
  • the electrolytic solution of the present invention can be appropriately produced using the specific dissolution means described in 1.
  • the method for producing the electrolytic solution of the present invention preferably includes a vibrational spectroscopic measurement step of performing vibrational spectroscopic measurement of the electrolytic solution being manufactured.
  • a vibrational spectroscopic measurement step for example, a method of sampling a part of each electrolytic solution in the middle of production and using it for vibration spectroscopic measurement, or a method of performing spectroscopic spectroscopic measurement of each electrolytic solution in situ (situ) But it ’s okay.
  • the solvent in addition to the organic solvent having a hetero element, the solvent has a low polarity (low dielectric constant) or a low donor number and does not exhibit a special interaction with a metal salt, that is, the present invention.
  • a solvent that does not affect the formation and maintenance of the clusters in the electrolyte can be added.
  • the solvent that does not exhibit a special interaction with the metal salt include benzene, toluene, ethylbenzene, o-xylene, m-xylene, p-xylene, 1-methylnaphthalene, hexane, heptane, and cyclohexane. it can.
  • a flame retardant solvent can be added to the electrolytic solution of the present invention.
  • a flame retardant solvent include halogen solvents such as carbon tetrachloride, tetrachloroethane, and hydrofluoroether, and phosphoric acid derivatives such as trimethyl phosphate and triethyl phosphate.
  • the electrolytic solution of the present invention when the electrolytic solution of the present invention is mixed with a polymer or an inorganic filler to form a mixture, the mixture contains the electrolytic solution and becomes a pseudo solid electrolyte.
  • the pseudo-solid electrolyte As the battery electrolyte, leakage of the electrolyte in the battery can be suppressed.
  • a polymer used for a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery or a general chemically crosslinked polymer can be used.
  • a polymer that can absorb an electrolyte such as polyvinylidene fluoride and polyhexafluoropropylene and gel can be used, and a polymer such as polyethylene oxide in which an ion conductive group is introduced.
  • polymers include polymethyl acrylate, polymethyl methacrylate, polyethylene oxide, polypropylene oxide, polyacrylonitrile, polyvinylidene fluoride, polyethylene glycol dimethacrylate, polyethylene glycol acrylate, polyglycidol, polytetrafluoroethylene, polyhexafluoropropylene, Polycarboxylic acid such as polysiloxane, polyvinyl acetate, polyvinyl alcohol, polyacrylic acid, polymethacrylic acid, polyitaconic acid, polyfumaric acid, polycrotonic acid, polyangelic acid, carboxymethylcellulose, styrene-butadiene rubber, nitrile-butadiene rubber, polystyrene , Polycarbonate, unsaturated polyester copolymerized with maleic anhydride and glycols, Polyethylene oxide derivative having a group, a copolymer of vinylidene fluoride and hexafluoropropylene can be exempl
  • Polysaccharides are also suitable as the polymer.
  • Specific examples of the polysaccharide include glycogen, cellulose, chitin, agarose, carrageenan, heparin, hyaluronic acid, pectin, amylopectin, xyloglucan, and amylose.
  • adopt the material containing these polysaccharides as said polymer The agar containing polysaccharides, such as agarose, can be illustrated as the said material.
  • the inorganic filler is preferably an inorganic ceramic such as oxide or nitride.
  • Inorganic ceramics have hydrophilic and hydrophobic functional groups on the surface. Therefore, when the functional group attracts the electrolytic solution, a conductive path can be formed in the inorganic ceramic. Furthermore, the inorganic ceramics dispersed in the electrolytic solution can form a network between the inorganic ceramics by the functional groups and serve to contain the electrolytic solution. With such a function of the inorganic ceramics, it is possible to more suitably suppress the leakage of the electrolytic solution in the battery. In order to suitably exhibit the above functions of the inorganic ceramics, the inorganic ceramics preferably have a particle shape, and particularly preferably have a particle size of nano level.
  • the inorganic ceramics include general alumina, silica, titania, zirconia, and lithium phosphate. Further, the inorganic ceramic itself may be lithium conductive, and specifically, Li 3 N, LiI, LiI—Li 3 N—LiOH, LiI—Li 2 S—P 2 O 5 , LiI—Li 2 S —P 2 S 5 , LiI—Li 2 S—B 2 S 3 , Li 2 O—B 2 S 3 , Li 2 O—V 2 O 3 —SiO 2 , Li 2 O—B 2 O 3 —P 2 O 5 , Li 2 O—B 2 O 3 —ZnO, Li 2 O—Al 2 O 3 —TiO 2 —SiO 2 —P 2 O 5 , LiTi 2 (PO 4 ) 3 , Li— ⁇ Al 2 O 3 , LiTaO 3 Can be illustrated.
  • Li 3 N LiI, LiI—Li 3 N—LiOH, LiI—Li 2 S—
  • Glass ceramics may be employed as the inorganic filler. Since glass ceramics can contain an ionic liquid, the same effect can be expected for the electrolytic solution of the present invention. Glass ceramics include compounds represented by xLi 2 S- (1-x) P 2 S 5 , those obtained by substituting part of S of the compound with other elements, and compounds of P of the compound. Examples in which the part is replaced with germanium can be exemplified.
  • the density d (g / cm 3 ) in the electrolytic solution of the present invention is preferably d ⁇ 1.2 or d ⁇ 2.2, more preferably 1.2 ⁇ d ⁇ 2.2.
  • a range of 24 ⁇ d ⁇ 2.0 is more preferable, a range of 1.26 ⁇ d ⁇ 1.8 is more preferable, and a range of 1.27 ⁇ d ⁇ 1.6 is particularly preferable.
  • the density d (g / cm 3 ) in the electrolytic solution of the present invention means the density at 20 ° C. D / c described below is a value obtained by dividing the above d by the salt concentration c (mol / L).
  • d / c is 0.15 ⁇ d / c ⁇ 0.71, preferably 0.15 ⁇ d / c ⁇ 0.56, and 0.25 ⁇ d / c ⁇ 0. Within the range of .56, more preferably within the range of 0.26 ⁇ d / c ⁇ 0.50, and particularly preferably within the range of 0.27 ⁇ d / c ⁇ 0.47.
  • D / c in the electrolytic solution of the present invention can be defined even when a metal salt and an organic solvent are specified.
  • d / c is preferably within the range of 0.42 ⁇ d / c ⁇ 0.56, and 0.44 ⁇ d / c ⁇ 0.52 The range of is more preferable.
  • d / c is preferably in the range of 0.35 ⁇ d / c ⁇ 0.41, and 0.36 ⁇ d / c ⁇ 0.39. The inside is more preferable.
  • d / c is preferably in the range of 0.32 ⁇ d / c ⁇ 0.46, and in the range of 0.34 ⁇ d / c ⁇ 0.42. The inside is more preferable.
  • d / c is preferably in the range of 0.25 ⁇ d / c ⁇ 0.48, and in the range of 0.25 ⁇ d / c ⁇ 0.38.
  • the range of 0.25 ⁇ d / c ⁇ 0.31 is still more preferable, and the range of 0.26 ⁇ d / c ⁇ 0.29 is still more preferable.
  • d / c is preferably in the range of 0.32 ⁇ d / c ⁇ 0.46, and in the range of 0.34 ⁇ d / c ⁇ 0.42. The inside is more preferable.
  • d / c is preferably in the range of 0.34 ⁇ d / c ⁇ 0.50, and in the range of 0.37 ⁇ d / c ⁇ 0.45. The inside is more preferable.
  • d / c is preferably in the range of 0.36 ⁇ d / c ⁇ 0.54, and in the range of 0.39 ⁇ d / c ⁇ 0.48. The inside is more preferable.
  • the electrolyte solution of the present invention is different in the environment in which the metal salt and the organic solvent are present and has a high density, so that the metal ion transport rate in the electrolyte solution is improved (particularly when the metal is lithium , Improvement in lithium transport number), improvement in the reaction rate between the electrode and the electrolyte solution, relaxation of uneven distribution of the salt concentration of the electrolyte that occurs during high-rate charge / discharge of the battery, and increase in the electric double layer capacity can be expected. Furthermore, in the electrolytic solution of the present invention, since the density is high, the vapor pressure of the organic solvent contained in the electrolytic solution is lowered. As a result, volatilization of the organic solvent from the electrolytic solution of the present invention can be reduced.
  • the viscosity of the electrolytic solution of the present invention is higher than that of the conventional electrolytic solution. For this reason, if the nonaqueous electrolyte secondary battery of the present invention using the electrolytic solution of the present invention is used, even if the battery is damaged, electrolyte leakage is suppressed. Moreover, the capacity
  • the metal concentration of the electrolytic solution of the present invention is higher than that of the conventional electrolytic solution.
  • the preferable Li concentration of the electrolytic solution of the present invention is about 2 to 5 times the Li concentration of a general electrolytic solution.
  • the electrolytic solution of the present invention containing Li at a high concentration, it is considered that the uneven distribution of Li is reduced, and as a result, the capacity reduction during the high-speed charge / discharge cycle is suppressed.
  • the electrolytic solution of the present invention has a high viscosity, the liquid retaining property of the electrolytic solution at the electrode interface is improved, and the state where the electrolytic solution is insufficient at the electrode interface (so-called liquid withdrawn state) can be suppressed. This is considered to be one of the reasons that the capacity decrease during the charge / discharge cycle is suppressed.
  • a range of 10 ⁇ ⁇ 500 is preferable, a range of 12 ⁇ ⁇ 400 is more preferable, a range of 15 ⁇ ⁇ 300 is further preferable, and 18 A range of ⁇ ⁇ 150 is particularly preferable, and a range of 20 ⁇ ⁇ 140 is most preferable.
  • the ion conductivity ⁇ (mS / cm) of the electrolytic solution of the present invention is preferably 1 ⁇ ⁇ .
  • a preferable range including the upper limit is preferably 2 ⁇ ⁇ 200, and preferably 3 ⁇ .
  • a range of ⁇ 100 is more preferred, a range of 4 ⁇ ⁇ 50 is more preferred, and a range of 5 ⁇ ⁇ 35 is particularly preferred.
  • an S, O-containing film is formed on the surface of the negative electrode and / or the positive electrode in the nonaqueous electrolyte secondary battery (1) of the present invention.
  • an S, O-containing film is also formed on the surface of the negative electrode and / or the positive electrode of the nonaqueous electrolyte secondary battery (2).
  • this film contains S and O, and has at least an S ⁇ O structure.
  • the electrolytic solution of the present invention it is considered that the Li cation and the anion are present in the vicinity as compared with a normal electrolytic solution.
  • the anion is preferentially reduced and decomposed by being strongly affected by the electrostatic influence from the Li cation.
  • an organic solvent for example, EC: ethylene carbonate
  • an SEI film is formed by a decomposition product of the organic solvent. Is configured.
  • anions are preferentially reduced and decomposed.
  • the SEI film that is, the S, O-containing film in the non-aqueous electrolyte secondary battery of the present invention contains a lot of S ⁇ O structures derived from anions. That is, in a normal nonaqueous electrolyte secondary battery using a normal electrolyte solution, an SEI film derived from a decomposition product of an organic solvent such as EC is fixed on the electrode surface. On the other hand, in the nonaqueous electrolyte secondary battery of the present invention using the electrolytic solution of the present invention, the SEI film mainly derived from the anion of the metal salt is fixed on the electrode surface.
  • the state of the S, O-containing film in the nonaqueous electrolyte secondary battery of the present invention changes with charge / discharge.
  • the S, O-containing film in the nonaqueous electrolyte secondary battery of the present invention is derived from the above-described decomposition product of anions and fixed in the film (hereinafter referred to as a fixing unit as required), It is considered that there is a portion that reversibly increases / decreases with charge / discharge (hereinafter referred to as an adsorption portion as necessary).
  • the adsorption part is presumed to have a structure such as S ⁇ O derived from the anion of the metal salt as in the fixing part.
  • the S, O-containing film is composed of a decomposition product of the electrolytic solution and is thought to contain other adsorbents, most (or all) of the S, O-containing film is the first charge / discharge of the nonaqueous electrolyte secondary battery. It is considered to be generated after the hour. That is, the nonaqueous electrolyte secondary battery of the present invention has an S, O-containing film on the surface of the negative electrode and / or the surface of the positive electrode in use.
  • Other constituent components of the S, O-containing coating are variously different depending on components other than sulfur and oxygen contained in the electrolytic solution, the composition of the negative electrode, and the like.
  • the S, O-containing film may be formed only on the negative electrode surface, or may be formed only on the positive electrode surface. However, as described above, since the S, O-containing film is considered to be derived from the anion of the metal salt contained in the electrolytic solution of the present invention, it contains more components derived from the anion of the metal salt than the other components. preferable.
  • the S, O-containing film is preferably formed on both the negative electrode surface and the positive electrode surface.
  • the S, O-containing film formed on the surface of the negative electrode is referred to as the negative electrode S, O-containing film
  • the S, O-containing film formed on the surface of the positive electrode is referred to as the positive electrode S, O-containing film as necessary.
  • an imide salt can be preferably used as the metal salt in the electrolytic solution of the present invention.
  • a technique for adding an imide salt to an electrolytic solution is known.
  • the coating on the positive electrode and / or the negative electrode is an organic solvent of the electrolytic solution.
  • compounds derived from decomposition products it is known to include compounds derived from imide salts, that is, compounds containing S.
  • a component derived from an imide salt partially contained in this film improves the durability of the nonaqueous electrolyte secondary battery while suppressing an increase in the internal resistance of the nonaqueous electrolyte secondary battery. It has been introduced to get.
  • the imide salt-derived component in the film could not be concentrated for the following reasons.
  • an SEI film is formed on the surface of the negative electrode in order to cause the graphite to react reversibly with the charge carrier and to reversibly charge and discharge the nonaqueous electrolyte secondary battery. It is considered necessary to be.
  • a cyclic carbonate compound typified by EC has been used as an organic solvent for the electrolytic solution.
  • coat was formed with the decomposition product of the said cyclic carbonate compound.
  • the conventional electrolyte solution containing an imide salt contains a large amount of cyclic carbonate such as EC as an organic solvent and also contains an imide salt as an additive.
  • the main component of the SEI film is a component derived from an organic solvent, and it is difficult to increase the content of the imide salt of the SEI film.
  • an imide salt is used as a metal salt (that is, an electrolyte salt or a supporting salt) rather than as an additive, it is necessary to consider a combination with a current collector for a positive electrode. That is, imide salts are known to corrode aluminum current collectors that are generally used as current collectors for positive electrodes. For this reason, when using the positive electrode which operates at a potential of about 4 V in particular, it is necessary to coexist with an aluminum current collector an electrolytic solution containing LiPF 6 or the like that forms an immobile with aluminum as an electrolyte salt.
  • the total concentration of the electrolyte salt composed of LiPF 6 or imide salt is optimally about 1 mol / L to 2 mol / L from the viewpoint of ionic conductivity and viscosity (Japanese Patent Laid-Open No. 2013-145732). ). Therefore, when a sufficient amount of LiPF 6 is added, the amount of imide salt added is inevitably reduced, so that there is a problem that it is difficult to use a large amount of imide salt as a metal salt for an electrolytic solution.
  • the imide salt may be simply abbreviated as a metal salt.
  • the electrolytic solution of the present invention contains a metal salt at a high concentration.
  • the metal salt is present in a state completely different from the conventional one.
  • a problem caused by the high concentration of the metal salt hardly occurs.
  • the electrolytic solution of the present invention it is possible to suppress a decrease in input / output performance of the nonaqueous electrolyte secondary battery due to an increase in the viscosity of the electrolytic solution, and it is also possible to suppress corrosion of the aluminum current collector.
  • the metal salt contained in the electrolytic solution at a high concentration is preferentially reduced and decomposed on the negative electrode.
  • an SEI film having a special structure derived from a metal salt, that is, an S, O-containing film is formed on the negative electrode without using a cyclic carbonate compound such as EC as the organic solvent. Therefore, the nonaqueous electrolyte secondary battery of the present invention can be reversibly charged and discharged without using a cyclic carbonate compound as an organic solvent even when graphite is used as the negative electrode active material.
  • the nonaqueous electrolyte secondary battery of the present invention uses a cyclic carbonate compound as the organic solvent or LiPF as the metal salt even when graphite is used as the negative electrode active material and an aluminum current collector is used as the positive electrode current collector. 6 can be reversibly charged / discharged. Furthermore, most of the SEI film on the negative electrode and / or positive electrode surface can be composed of anion-derived components. As will be described later, the S, O-containing film containing an anion-derived component can improve the battery characteristics of the nonaqueous electrolyte secondary battery.
  • the negative electrode film includes many polymer structures in which carbon derived from the EC solvent is polymerized.
  • the negative electrode S, O-containing film in the nonaqueous electrolyte secondary battery of the present invention contains almost no (or no) polymer structure obtained by polymerizing such carbon, and is derived from an anion of a metal salt. Including many. The same applies to the positive electrode film.
  • the electrolytic solution of the present invention contains a metal salt cation in a high concentration.
  • the distance between adjacent cations is extremely short.
  • cations such as lithium ions move between the positive electrode and the negative electrode during charge / discharge of the nonaqueous electrolyte secondary battery
  • the cations closest to the destination electrode are first supplied to the electrode.
  • the other cation adjacent to the said cation moves to the place with the said supplied cation.
  • the reaction rate of the nonaqueous electrolyte secondary battery of the present invention having the electrolytic solution of the present invention is considered to be high.
  • the nonaqueous electrolyte secondary battery of the present invention has an S, O-containing film on an electrode (that is, a negative electrode and / or a positive electrode), and the S, O-containing film has an S ⁇ O structure and contains many cations. it is conceivable that. It is considered that cations contained in the S, O-containing film are preferentially supplied to the electrode.
  • the cation transport rate is further improved by having an abundant cation source (that is, an S, O-containing film) in the vicinity of the electrode. Therefore, in the nonaqueous electrolyte secondary battery of the present invention, it is considered that excellent battery characteristics are exhibited by the cooperation of the electrolytic solution of the present invention and the S, O-containing film.
  • the SEI film of the negative electrode is constituted by a deposit of the electrolytic solution generated by reductive decomposition of the electrolytic solution at a predetermined voltage or less. That is, in order to efficiently generate the above-described S, O-containing film on the surface of the negative electrode, the non-aqueous electrolyte secondary battery of the present invention should have the minimum value of the negative electrode potential not more than a predetermined value. Specifically, the nonaqueous electrolyte secondary battery of the present invention is suitable as a battery to be used under the condition that the minimum value of the negative electrode potential is 1.3 V or less when the counter electrode is lithium.
  • the negative electrode in the nonaqueous electrolyte secondary battery of the present invention is not particularly limited.
  • the negative electrode active material a general material that can occlude and release charge carriers can be used.
  • a material capable of inserting and extracting lithium ions may be selected as the negative electrode active material.
  • an element (single element) that can be alloyed with a charge carrier such as Li, an alloy containing the element, or a compound containing the element may be used.
  • a group 14 element such as Li, carbon, silicon, germanium or tin, a group 13 element such as aluminum or indium, a group 12 element such as zinc or cadmium, 15 such as antimony or bismuth, etc.
  • a group element, an alkaline earth metal such as magnesium and calcium, and a group 11 element such as silver and gold may be employed alone.
  • an alloy or a compound in which another element such as a transition metal is combined with a simple substance such as silicon as the negative electrode active material.
  • the alloy or compound include tin-based materials such as Ag—Sn alloy, Cu—Sn alloy and Co—Sn alloy, carbon-based materials such as various graphites, SiO x (disproportionated to silicon simple substance and silicon dioxide). Examples thereof include silicon-based materials such as 0.3 ⁇ x ⁇ 1.6), silicon alone, or composites obtained by combining silicon-based materials and carbon-based materials.
  • M Co Nitride represented by Ni, Cu
  • the non-aqueous electrolyte secondary battery (1) of the present invention has an S, O-containing film formed on the negative electrode surface. Therefore, it can respond to a low potential negative electrode.
  • a material containing a carbon element such as graphite or a Si-based negative electrode active material can be selected as the negative electrode active material.
  • the particle diameter of graphite is not particularly limited, whether natural or artificial.
  • the non-aqueous electrolyte secondary battery of the present invention includes a negative electrode having a negative electrode active material capable of occluding and releasing charge carriers such as lithium ions, a positive electrode having a positive electrode active material capable of occluding and releasing the charge carriers, and
  • the electrolytic solution of the present invention is provided.
  • the non-aqueous electrolyte secondary battery of the present invention is a lithium ion secondary battery
  • the negative electrode active material can occlude and release lithium ions
  • the positive electrode active material can occlude and release lithium ions.
  • the electrolytic solution employs a lithium salt as a metal salt.
  • the negative electrode has a current collector and a negative electrode active material layer bound to the surface of the current collector.
  • the negative electrode active material has already been described.
  • the current collector is a chemically inert electronic high conductor that keeps a current flowing through an electrode during discharge or charging of a nonaqueous electrolyte secondary battery.
  • As the current collector for the negative electrode at least one selected from silver, copper, gold, aluminum, tungsten, cobalt, zinc, nickel, iron, platinum, tin, indium, titanium, ruthenium, tantalum, chromium, molybdenum, and stainless steel A metal material such as steel can be exemplified.
  • the current collector may be covered with a known protective layer. What collected the surface of the electrical power collector by the well-known method may be used as an electrical power collector.
  • the current collector can take the form of a foil, a sheet, a film, a linear shape, a rod shape, a mesh, or the like. Therefore, for example, a metal foil such as a copper foil, a nickel foil, an aluminum foil, and a stainless steel foil can be suitably used as the current collector.
  • a metal foil such as a copper foil, a nickel foil, an aluminum foil, and a stainless steel foil can be suitably used as the current collector.
  • the thickness is preferably in the range of 1 ⁇ m to 100 ⁇ m.
  • the negative electrode active material layer includes a negative electrode active material and, if necessary, a binder and / or a conductive aid.
  • the non-aqueous electrolyte secondary battery (2) uses a specific binder.
  • the binder serves to bind the negative electrode active material particles or the negative electrode active material and the conductive auxiliary agent to the surface of the current collector.
  • the nonaqueous electrolyte secondary battery (2) contains a polymer having a hydrophilic group in the binder.
  • the hydrophilic group of the polymer having a hydrophilic group include a phosphate group such as a carboxyl group, a sulfo group, a silanol group, an amino group, a hydroxyl group, an amino group, and a phosphate group.
  • a polymer containing a carboxyl group in the molecule such as polyacrylic acid (PAA), carboxymethyl cellulose (CMC), or polymethacrylic acid, or a polymer containing a sulfo group such as poly (P-styrenesulfonic acid) is preferable.
  • PAA polyacrylic acid
  • CMC carboxymethyl cellulose
  • Polymers containing a large amount of carboxyl groups and / or sulfo groups such as polyacrylic acid or a copolymer of acrylic acid and vinyl sulfonic acid, are water-soluble. Therefore, the polymer having a hydrophilic group is preferably a water-soluble polymer, and a polymer containing a plurality of carboxyl groups and / or sulfo groups in one molecule is preferable.
  • the polymer containing a carboxyl group in the molecule can be produced by, for example, a method of polymerizing an acid monomer such as polyacrylic acid or a method of imparting a carboxyl group to a polymer such as carboxymethyl cellulose (CMC).
  • a method of polymerizing an acid monomer such as polyacrylic acid
  • a method of imparting a carboxyl group to a polymer such as carboxymethyl cellulose (CMC).
  • Acid monomers include acrylic acid, methacrylic acid, vinyl benzoic acid, crotonic acid, pentenoic acid, angelic acid, tiglic acid, etc., acid monomers having one carboxyl group in the molecule, itaconic acid, mesaconic acid, citraconic acid, fumaric acid Examples include maleic acid, 2-pentenedioic acid, methylene succinic acid, allyl malonic acid, isopropylidene succinic acid, 2,4-hexadiene diacid, acetylenedicarboxylic acid, and other acid monomers having two or more carboxyl groups in the molecule. Is done. A copolymer obtained by polymerizing two or more kinds of monomers selected from these may be used.
  • a polymer composed of a copolymer of acrylic acid and itaconic acid as described in JP2013-065493A, and containing an acid anhydride group formed by condensation of carboxyl groups in the molecule It is also preferable to use as a binder.
  • the structure derived from a highly acidic monomer having two or more carboxyl groups in one molecule is considered to facilitate trapping of lithium ions and the like before the electrolytic solution decomposition reaction occurs during charging.
  • the acidity is not excessively increased because there are more carboxyl groups and the acidity is higher than polyacrylic acid and polymethacrylic acid, and a predetermined amount of the carboxyl groups are changed to acid anhydride groups. Therefore, a secondary battery having a negative electrode formed using this negative electrode binder has improved initial efficiency and improved input / output characteristics.
  • fluorine-containing resins such as polyvinylidene fluoride, polytetrafluoroethylene, and fluororubber, thermoplastic resins such as polypropylene and polyethylene, imide resins such as polyimide and polyamideimide, and alkoxysilyl group-containing resins A polymer such as
  • the binder of the non-aqueous electrolyte secondary battery (1) may be the above-mentioned binder or other binders.
  • binders include fluorine-containing resins such as polyvinylidene fluoride, polytetrafluoroethylene, and fluororubber, thermoplastic resins such as polypropylene and polyethylene, imide resins such as polyimide and polyamideimide, and alkoxysilyl group-containing resins. can do.
  • Conductive aid is added to increase the conductivity of the electrode. Therefore, the conductive auxiliary agent may be added arbitrarily when the electrode conductivity is insufficient, and may not be added when the electrode conductivity is sufficiently excellent.
  • the conductive auxiliary agent may be any chemically inert electronic high conductor, such as carbon black, graphite, acetylene black, ketjen black (registered trademark), vapor grown carbon fiber (Vapor Growth Carbon, carbonaceous fine particles). Fiber: VGCF) and various metal particles are exemplified. These conductive assistants can be added to the active material layer alone or in combination of two or more.
  • a negative electrode active material powder, a conductive aid such as carbon powder, the binder, and an appropriate amount of solvent are added and mixed.
  • the slurry is applied to the current collector by a roll coating method, dip coating method, doctor blade method, spray coating method, curtain coating method, etc., and the binder is produced by drying or curing.
  • the solvent include N-methyl-2-pyrrolidone, methanol, methyl isobutyl ketone, and water.
  • the dried product may be compressed.
  • a positive electrode used for a non-aqueous electrolyte secondary battery has a positive electrode active material that can occlude and release charge carriers such as lithium ions.
  • the positive electrode has a current collector and a positive electrode active material layer bound to the surface of the current collector.
  • the positive electrode active material layer includes a positive electrode active material and, if necessary, a binder and / or a conductive aid.
  • the positive electrode current collector is not particularly limited as long as it is a metal that can withstand a voltage suitable for the active material to be used.
  • silver, copper, gold, aluminum, tungsten, cobalt, zinc, nickel, iron, platinum, tin , Indium, titanium, ruthenium, tantalum, chromium, molybdenum, and metal materials such as stainless steel.
  • the potential of the positive electrode is 4 V or higher with respect to lithium, it is preferable to employ aluminum as the current collector.
  • the positive electrode current collector is preferably made of aluminum or an aluminum alloy.
  • aluminum refers to pure aluminum, and aluminum having a purity of 99.0% or more is referred to as pure aluminum.
  • An alloy obtained by adding various elements to pure aluminum is referred to as an aluminum alloy. Examples of the aluminum alloy include Al—Cu, Al—Mn, Al—Fe, Al—Si, Al—Mg, AL—Mg—Si, and Al—Zn—Mg.
  • aluminum or aluminum alloy examples include, for example, A1000 series alloys (pure aluminum series) such as JIS A1085 and A1N30, A3000 series alloys (Al-Mn series) such as JIS A3003 and A3004, JIS A8079, A8021, etc. A8000-based alloy (Al-Fe-based).
  • the current collector may be covered with a known protective layer. What collected the surface of the electrical power collector by the well-known method may be used as an electrical power collector.
  • the current collector can take the form of a foil, a sheet, a film, a linear shape, a rod shape, a mesh, or the like. Therefore, for example, a metal foil such as a copper foil, a nickel foil, an aluminum foil, and a stainless steel foil can be suitably used as the current collector.
  • a metal foil such as a copper foil, a nickel foil, an aluminum foil, and a stainless steel foil can be suitably used as the current collector.
  • the thickness is preferably in the range of 1 ⁇ m to 100 ⁇ m. The same applies to the negative electrode current collector described above.
  • the binder for the positive electrode and the conductive additive are the same as those described for the negative electrode.
  • a positive electrode active material a solid solution composed of a spinel such as LiMn 2 O 4 and a mixture of a spinel and a layered compound, LiMPO 4 , LiMVO 4 or Li 2 MSiO 4 (wherein M is Co, Ni, Mn, And a polyanionic compound represented by (selected from at least one of Fe).
  • tavorite compound the M a transition metal
  • LiMPO 4 F such as LiFePO 4 F represented by, Limbo 3 such LiFeBO 3 (M is a transition metal
  • Limbo 3 such LiFeBO 3 (M is a transition metal
  • M is a transition metal
  • any metal oxide used as the positive electrode active material may have the above composition formula as a basic composition, and a metal element contained in the basic composition may be substituted with another metal element.
  • a charge carrier for example, lithium ion which contributes to charging / discharging.
  • sulfur alone (S) a compound in which sulfur and carbon are compounded
  • a metal sulfide such as TiS 2
  • an oxide such as V 2 O 5 and MnO 2
  • conjugated materials such as conjugated diacetate-based organic substances and other known materials can also be used.
  • a compound having a stable radical such as nitroxide, nitronyl nitroxide, galvinoxyl, phenoxyl, etc. may be adopted as the positive electrode active material.
  • the charge carrier may be added in an ionic state or in a non-ionic state such as a metal.
  • the charge carrier is lithium, it may be integrated by attaching a lithium foil to the positive electrode and / or the negative electrode.
  • the positive electrode may contain a conductive additive, a binder, and the like, similarly to the negative electrode.
  • the conductive aid and the binder are not particularly limited as long as they can be used for the nonaqueous electrolyte secondary battery as in the case of the negative electrode described above.
  • a current collecting method such as a roll coating method, a die coating method, a dip coating method, a doctor blade method, a spray coating method, or a curtain coating method
  • An active material may be applied to the surface of the body.
  • an active material layer-forming composition (so-called negative electrode mixture, positive electrode mixture) containing an active material and, if necessary, a binder and a conductive additive is prepared, and a suitable solvent for this composition Is applied to the surface of the current collector and then dried.
  • the solvent include N-methyl-2-pyrrolidone, methanol, methyl isobutyl ketone, and water.
  • the dried product may be compressed.
  • a separator is used for non-aqueous electrolyte secondary batteries as necessary.
  • the separator separates the positive electrode and the negative electrode and allows lithium ions to pass while preventing a short circuit of current due to contact between the two electrodes.
  • natural resins such as polytetrafluoroethylene, polypropylene, polyethylene, polyimide, polyamide, polyaramid (Aromatic polymer), polyester, polyacrylonitrile, etc., polysaccharides such as cellulose, amylose, fibroin, keratin, lignin, suberin, etc. Examples thereof include porous bodies, nonwoven fabrics, and woven fabrics using one or more electrically insulating materials such as polymers and ceramics.
  • the separator may have a multilayer structure.
  • the electrolytic solution of the present invention has a slightly high viscosity and a high polarity
  • a membrane in which a polar solvent such as water can easily penetrate is preferable.
  • a film in which a polar solvent such as water soaks into 90% or more of the existing voids is more preferable.
  • a separator is sandwiched between the positive electrode and the negative electrode as necessary to form an electrode body.
  • the electrode body may be either a stacked type in which the positive electrode, the separator and the negative electrode are stacked, or a wound type in which the positive electrode, the separator and the negative electrode are sandwiched.
  • the electrolyte solution of the present invention is added to the electrode body to make a non-aqueous solution. It is preferable to use an electrolyte secondary battery.
  • the non-aqueous electrolyte secondary battery of this invention should just be charged / discharged in the voltage range suitable for the kind of active material contained in an electrode.
  • the shape of the nonaqueous electrolyte secondary battery of the present invention is not particularly limited, and various shapes such as a cylindrical shape, a square shape, a coin shape, and a laminate shape can be adopted.
  • the non-aqueous electrolyte secondary battery of the present invention may be of any type of charge carrier. Therefore, the nonaqueous electrolyte secondary battery of the present invention may be, for example, a lithium ion secondary battery or a lithium secondary battery. Alternatively, a charge carrier other than lithium (for example, sodium) may be used.
  • the nonaqueous electrolyte secondary battery of the present invention may be mounted on a vehicle.
  • the vehicle may be a vehicle that uses electric energy from the nonaqueous electrolyte secondary battery for all or a part of its power source, and may be, for example, an electric vehicle or a hybrid vehicle.
  • non-aqueous electrolyte secondary battery When a non-aqueous electrolyte secondary battery is mounted on a vehicle, a plurality of non-aqueous electrolyte secondary batteries may be connected in series to form an assembled battery.
  • devices equipped with non-aqueous electrolyte secondary batteries include personal computers, portable communication devices, and various household electrical appliances driven by batteries, office equipment, industrial equipment, and the like.
  • non-aqueous electrolyte secondary battery of the present invention includes wind power generation, solar power generation, hydroelectric power generation and other power system power storage devices and power smoothing devices, power for power sources such as ships, and / or power supply sources for auxiliary machinery, aircraft Power supplies for spacecrafts and / or auxiliary equipment, auxiliary power sources for vehicles that do not use electricity as power sources, mobile home robot power sources, system backup power sources, uninterruptible power supply power sources
  • it may be used for a power storage device that temporarily stores electric power required for charging at an electric vehicle charging station or the like.
  • the obtained electrolytic solution had a volume of 20 mL, and (CF 3 SO 2 ) 2 NLi contained in this electrolytic solution was 18.38 g.
  • the concentration of (CF 3 SO 2 ) 2 NLi in the electrolytic solution E1 was 3.2 mol / L.
  • 1.6 molecules of 1,2-dimethoxyethane are contained with respect to (CF 3 SO 2 ) 2 NLi1 molecules.
  • the above production was carried out in a glove box under an inert gas atmosphere.
  • the concentration of (CF 3 SO 2 ) 2 NLi in the electrolytic solution E3 was 3.4 mol / L.
  • 3 molecules of acetonitrile are contained with respect to 1 molecule of (CF 3 SO 2 ) 2 NLi.
  • (E7) Except for using (FSO 2) 2 NLi of 15.72g as lithium salt, in a similar manner as E3, to produce an electrolyte E7 is (FSO 2) concentration of 2 NLi is 4.2 mol / L. In the electrolytic solution E7, 3 molecules of acetonitrile are contained with respect to 1 molecule of (FSO 2 ) 2 NLi.
  • the concentration of (FSO 2 ) 2 NLi in the electrolytic solution E11 was 3.9 mol / L.
  • two molecules of dimethyl carbonate are contained with respect to one molecule of (FSO 2 ) 2 NLi.
  • the concentration of (FSO 2 ) 2 NLi in the electrolytic solution E16 was 3.4 mol / L.
  • two molecules of ethyl methyl carbonate are contained with respect to one molecule of (FSO 2 ) 2 NLi.
  • the electrolyte solution E16 was diluted by adding ethyl methyl carbonate to obtain an electrolyte solution E17 having a (FSO 2 ) 2 NLi concentration of 2.9 mol / L.
  • the electrolytic solution E17 2.5 molecules of ethyl methyl carbonate are contained per 1 molecule of (FSO 2 ) 2 NLi.
  • the electrolyte solution E16 was diluted by adding ethyl methyl carbonate to obtain an electrolyte solution E18 having a concentration of (FSO 2 ) 2 NLi of 2.2 mol / L.
  • the electrolytic solution E18 3.5 molecules of ethyl methyl carbonate are contained with respect to (FSO 2 ) 2 NLi1 molecules.
  • the concentration of (FSO 2 ) 2 NLi in the electrolytic solution E19 was 3.0 mol / L.
  • two molecules of diethyl carbonate are contained with respect to one molecule of (FSO 2 ) 2 NLi.
  • the electrolyte solution E16 was diluted by adding ethyl methyl carbonate to obtain an electrolyte solution C7 having a (FSO 2 ) 2 NLi concentration of 1.1 mol / L.
  • 8 molecules of ethyl methyl carbonate are contained with respect to (FSO 2 ) 2 NLi1 molecule.
  • Table 3 shows a list of electrolytes.
  • IR measurement was performed on the electrolytic solutions E3, E4, E7, E8, E10, C2, C4, acetonitrile, (CF 3 SO 2 ) 2 NLi, and (FSO 2 ) 2 NLi under the following conditions.
  • IR spectra in the range of 2100 to 2400 cm ⁇ 1 are shown in FIGS. 1 to 10, respectively.
  • the horizontal axis in the figure is the wave number (cm ⁇ 1 ), and the vertical axis is the absorbance (reflection absorbance).
  • IR measurement was performed on the electrolytic solutions E11 to E21, the electrolytic solutions C6 to C8, dimethyl carbonate, ethyl methyl carbonate, and diethyl carbonate under the following conditions.
  • FIGS. 11 to 27 show IR spectra in the range of 1900 to 1600 cm ⁇ 1 in FIGS. 11 to 27, respectively.
  • FIG. 28 shows an IR spectrum in the range of 1900 to 1600 cm ⁇ 1 for (FSO 2 ) 2 NLi.
  • the horizontal axis in the figure is the wave number (cm ⁇ 1 ), and the vertical axis is the absorbance (reflection absorbance).
  • IR measurement conditions Device FT-IR (Bruker Optics) Measurement conditions: ATR method (using diamond) Measurement atmosphere: Inert gas atmosphere
  • FIG. IR spectrum of the electrolyte E10 represented by 5 is not a peak derived from acetonitrile observed around 2250 cm -1, inter 2250 cm from the vicinity -1 shifted acetonitrile 2280cm around -1 to the high frequency side C and N
  • the relationship between the peak intensities of Is and Io was Is> Io.
  • FIGS. 29 to 35 show Raman spectra in which peaks derived from the anion portion of the metal salt of each electrolytic solution were observed.
  • the horizontal axis represents the wave number (cm ⁇ 1 ), and the vertical axis represents the scattering intensity.
  • a characteristic peak derived from (FSO 2 ) 2 N of LiFSA dissolved in dimethyl carbonate is observed in 700 to 800 cm ⁇ 1 of the Raman spectra of the electrolytic solutions E11, E13, E15, and C6 shown in FIGS. Observed.
  • the peak shifts to the higher wavenumber side as the concentration of LiFSA increases. This phenomenon is similar to that discussed in the previous paragraph.
  • the concentration of the electrolyte is increased, the state in which (FSO 2 ) 2 N corresponding to the anion of the salt interacts with a plurality of Li is shown in the spectrum. It is inferred that the result is reflected.
  • Ionic conductivity measurement conditions In an Ar atmosphere, an electrolytic solution was sealed in a glass cell with a platinum constant and a known cell constant, and impedance at 30 ° C. and 1 kHz was measured. The ion conductivity was calculated from the impedance measurement result.
  • Solartron 147055BEC Solartron
  • Electrolytes E1, E2, E4 to E6, E8, E11, E16 and E19 all exhibited ionic conductivity. Therefore, it can be understood that the electrolytic solution of the present invention can function as an electrolytic solution for various batteries.
  • Viscosity measurement conditions Using a falling ball viscometer (Lovis 2000M manufactured by Anton Paar GmbH (Anton Paar)), an electrolytic solution was sealed in a test cell under an Ar atmosphere, and the viscosity was measured at 30 ° C.
  • the maximum volatilization rates of the electrolytic solutions E2, E4, E8, E11, and E13 were significantly smaller than the maximum volatilization rates of the electrolytic solutions C1, C2, C4, and C6. Therefore, even if the battery using the electrolytic solution of the present invention is damaged, the volatilization rate of the electrolytic solution is small, so that rapid volatilization of the organic solvent to the outside of the battery is suppressed.
  • EB1 A half cell using the electrolytic solution E8 was produced as follows. 90 parts by mass of graphite having an average particle diameter of 10 ⁇ m as an active material and 10 parts by mass of polyvinylidene fluoride as a binder were mixed. This mixture was dispersed in an appropriate amount of N-methyl-2-pyrrolidone to prepare a slurry.
  • a copper foil having a thickness of 20 ⁇ m was prepared as a current collector.
  • the slurry was applied in a film form on the surface of the copper foil using a doctor blade.
  • the copper foil coated with the slurry was dried to remove N-methyl-2-pyrrolidone, and then the copper foil was pressed to obtain a bonded product.
  • the obtained joined product was heat-dried at 120 ° C. for 6 hours with a vacuum dryer to obtain a copper foil on which an active material layer was formed. This was the working electrode.
  • the counter electrode was metal Li.
  • This non-aqueous electrolyte secondary battery is a non-aqueous electrolyte secondary battery for evaluation, and is also called a half cell.
  • CB1 A nonaqueous electrolyte secondary battery CB1 was produced in the same manner as in EB1, except that the electrolytic solution C5 was used.
  • EB1 exhibited a superior rate characteristic as compared to CB1, with a decrease in capacity suppressed at any rate of 0.2C, 0.5C, 1C, and 2C. It was confirmed that the secondary battery using the electrolytic solution of the present invention exhibits excellent rate characteristics.
  • CB1 has a tendency to increase the polarization when a current is passed at a rate of 1C as charging and discharging are repeated, and the capacity obtained from reaching 2V to 0.01V rapidly decreases.
  • EB1 was repeatedly charged and discharged, there was almost no increase / decrease in polarization as can be confirmed from the overlapping of the three curves in FIG.
  • the reason why the polarization increased in CB1 was that the electrolyte solution could not supply a sufficient amount of Li to the reaction interface with the electrode due to the Li concentration unevenness generated in the electrolyte solution when the charge and discharge were repeated rapidly. That is, the uneven distribution of Li concentration in the electrolytic solution can be considered.
  • Li transport rate measurement conditions The NMR tube containing the electrolyte was supplied to a PFG-NMR apparatus (ECA-500, JEOL), and 7 Li, 19 F was used as a target in each electrolyte while changing the magnetic field pulse width using the spin echo method.
  • the diffusion coefficients of Li ions and anions were measured.
  • the Li transport number of the electrolytic solutions E2 and E8 was significantly higher than the Li transport number of the electrolytic solutions C4 and C5.
  • the Li ion conductivity of the electrolytic solution can be calculated by multiplying the ionic conductivity (total ionic conductivity) contained in the electrolytic solution by the Li transport number. If it does so, it can be said that the electrolyte solution of this invention has the high transport rate of lithium ion (cation) compared with the conventional electrolyte solution which shows comparable ionic conductivity.
  • electrolyte solution E8 the Li transport number at the time of changing temperature was measured according to the said Li transport number measurement conditions. The results are shown in Table 9. From the results in Table 9, it can be seen that the electrolytic solution of the present invention maintains a suitable Li transport number regardless of the temperature. It can be said that the electrolytic solution of the present invention maintains a liquid state even at a low temperature.
  • Nonaqueous electrolyte secondary battery EB2 using electrolytic solution E8 was produced as follows.
  • a lithium-containing metal oxide having a layered rock salt structure represented by LiNi 5/10 Co 2/10 Mn 3/10 O 2 as a positive electrode active material, 3 parts by mass of acetylene black as a conductive auxiliary agent, and a binder 3 parts by mass of polyvinylidene fluoride as an agent was mixed. This mixture was dispersed in an appropriate amount of N-methyl-2-pyrrolidone to prepare a slurry.
  • An aluminum foil (JIS A1000 series) having a thickness of 20 ⁇ m was prepared as a positive electrode current collector. The slurry was applied to the surface of the aluminum foil using a doctor blade so as to form a film. The aluminum foil coated with the slurry was dried at 80 ° C.
  • NCM523 LiNi 5/10 Co 2/10 Mn 3/10 O 2
  • AB acetylene black
  • PVdF polyvinylidene fluoride
  • SBR styrene butadiene rubber
  • CMC carboxymethyl cellulose
  • a cellulose nonwoven fabric having a thickness of 20 ⁇ m was prepared as a separator.
  • a separator was sandwiched between the positive electrode and the negative electrode to form an electrode plate group.
  • the electrode plate group was covered with a set of two laminated films, and the three sides were sealed, and then the electrolyte solution E8 was injected into the laminated film in a bag shape. Thereafter, the remaining one side was sealed to obtain a nonaqueous electrolyte secondary battery in which the four sides were hermetically sealed and the electrode plate group and the electrolyte were sealed.
  • This battery was designated as a nonaqueous electrolyte secondary battery EB2.
  • EB3 A nonaqueous electrolyte secondary battery EB3 using the electrolytic solution E8 was produced as follows.
  • the positive electrode was manufactured in the same manner as the positive electrode of the nonaqueous electrolyte secondary battery EB2. 90 parts by mass of natural graphite as a negative electrode active material and 10 parts by mass of polyvinylidene fluoride as a binder were mixed. This mixture was dispersed in an appropriate amount of ion-exchanged water to prepare a slurry. A copper foil having a thickness of 20 ⁇ m was prepared as a negative electrode current collector. The slurry was applied in a film form on the surface of the copper foil using a doctor blade. The copper foil coated with the slurry was dried to remove water, and then the copper foil was pressed to obtain a bonded product. The obtained joined product was heat-dried at 120 ° C. for 6 hours with a vacuum dryer to obtain a copper foil on which a negative electrode active material layer was formed. This was used as a negative electrode.
  • a cellulose nonwoven fabric having a thickness of 20 ⁇ m was prepared as a separator.
  • a separator was sandwiched between the positive electrode and the negative electrode to form an electrode plate group.
  • the electrode plate group was covered with a set of two laminated films, and the three sides were sealed, and then the electrolyte solution E8 was injected into the laminated film in a bag shape. Thereafter, the remaining one side was sealed to obtain a nonaqueous electrolyte secondary battery in which the four sides of the laminate film were sealed, and the electrode plate group and the electrolyte were sealed in the laminate film.
  • This battery was designated as a nonaqueous electrolyte secondary battery EB3.
  • CB2 A nonaqueous electrolyte secondary battery CB2 was produced in the same manner as EB2, except that the electrolytic solution C5 was used.
  • CB3 A nonaqueous electrolyte secondary battery CB3 was produced in the same manner as EB3 except that the electrolytic solution C5 was used.
  • the battery output density (W / L) at 25 ° C. for 2 seconds was calculated.
  • Table 10 shows the evaluation results of the input characteristics.
  • “2 seconds input” means an input 2 seconds after the start of charging
  • “5 seconds input” means an input 5 seconds after the start of charging.
  • the EB2 input was significantly higher than the CB2 input regardless of the temperature difference.
  • EB3 input was significantly higher than CB3 input.
  • the battery input density of EB2 was significantly higher than the battery input density of CB2.
  • the battery input density of EB3 was significantly higher than that of CB3.
  • the battery output density (W / L) at 25 ° C. for 2 seconds output was calculated.
  • Table 10 shows the evaluation results of the output characteristics.
  • “2 seconds output” means an output 2 seconds after the start of discharge
  • “5 seconds output” means an output 5 seconds after the start of discharge.
  • the battery output density of EB2 was significantly higher than that of CB2.
  • the battery output density of EB3 was significantly higher than that of CB3.
  • Electrolytes E11, E13, E16, and E19 were placed in containers, filled with an inert gas, and sealed. These were stored in a freezer at ⁇ 30 ° C. for 2 days. Each electrolyte was observed after storage. None of the electrolytes were solidified and maintained in a liquid state, and no salt deposition was observed.
  • Example 1-1 A nonaqueous electrolyte secondary battery of Example 1-1 using the electrolytic solution E8 was produced as follows.
  • the positive electrode was manufactured in the same manner as the positive electrode of the nonaqueous electrolyte secondary battery EB2.
  • experimental filter paper As a separator, experimental filter paper (Toyo Filter Paper Co., Ltd., cellulose, thickness 260 ⁇ m) was prepared. A separator was sandwiched between the positive electrode and the negative electrode to form an electrode plate group. The electrode plate group was covered with a set of two laminated films, and the three sides were sealed, and then the electrolyte solution E8 was injected into the laminated film in a bag shape. Thereafter, the remaining one side was sealed to obtain a nonaqueous electrolyte secondary battery in which the four sides were hermetically sealed and the electrode plate group and the electrolyte were sealed. This battery was designated as the nonaqueous electrolyte secondary battery of Example 1-1.
  • Example 1-2 The nonaqueous electrolyte secondary battery of Example 1-2 is the same as the nonaqueous electrolyte secondary battery of Example 1-1 except that the electrolytic solution E4 was used as the electrolytic solution.
  • the electrolytic solution in the nonaqueous electrolyte secondary battery of Example 1-2 is obtained by dissolving (SO 2 CF 3 ) 2 NLi (LiTFSA) as a supporting salt in acetonitrile as a solvent.
  • the concentration of the lithium salt contained in 1 liter of the electrolytic solution is 4.2 mol / L.
  • the electrolytic solution contains two molecules of acetonitrile with respect to one molecule of the lithium salt.
  • Example 1-3 The nonaqueous electrolyte secondary battery of Example 1-3 is the same as the nonaqueous electrolyte secondary battery of Example 1-1 except that the electrolytic solution E11 was used as the electrolytic solution.
  • the electrolyte solution in the nonaqueous electrolyte secondary battery of Example 1-3 is obtained by dissolving LiFSA as a supporting salt in DMC as a solvent.
  • the concentration of the lithium salt contained in 1 liter of the electrolytic solution is 3.9 mol / L.
  • the electrolytic solution contains two molecules of DMC with respect to one molecule of the lithium salt.
  • the non-aqueous electrolyte secondary battery of Example 1-4 uses the electrolytic solution E11.
  • the non-aqueous electrolyte secondary battery of Example 1-4 includes the type of electrolyte, the mixing ratio of the positive electrode active material, the conductive additive, and the binder, the mixing ratio of the negative electrode active material and the binder, and other than the separator. These are the same as the nonaqueous electrolyte secondary battery of Example 1-1.
  • NCM523 was used as the positive electrode active material
  • AB was used as the conductive additive for the positive electrode
  • PVdF was used as the binder. This is the same as in Example 1-1.
  • Example 1-5 to 1-7 and Comparative Examples 1-2 and 1-3 below A cellulose nonwoven fabric with a thickness of 20 ⁇ m was used as the separator.
  • the electrolyte solution in the nonaqueous electrolyte secondary battery of Example 1-4 is obtained by dissolving LiFSA as a supporting salt in DMC as a solvent.
  • the concentration of the lithium salt contained in 1 liter of the electrolytic solution is 3.9 mol / L.
  • the electrolytic solution contains two molecules of DMC with respect to one molecule of the lithium salt.
  • the non-aqueous electrolyte secondary battery of Example 1-5 uses the electrolytic solution E8.
  • the non-aqueous electrolyte secondary battery of Example 1-5 is the same as Example 1 except for the mixing ratio of the positive electrode active material, the conductive additive and the binder, the mixing ratio of the negative electrode active material and the binder, and the separator. 1 is the same as the nonaqueous electrolyte secondary battery.
  • a cellulose nonwoven fabric with a thickness of 20 ⁇ m was used as the separator.
  • the non-aqueous electrolyte secondary battery of Example 1-6 uses the electrolytic solution E11.
  • the non-aqueous electrolyte secondary battery of Example 1-6 includes the type of electrolytic solution, the mixing ratio of the positive electrode active material, the conductive additive, and the binder, the type of binder for the negative electrode, and the negative electrode active material and the binder. Except for the mixing ratio with the agent and the separator, the non-aqueous electrolyte secondary battery of Example 1-1 is the same.
  • natural graphite was used as the negative electrode active material
  • PAA polyacrylic acid
  • PAA 90: 10.
  • a cellulose nonwoven fabric with a thickness of 20 ⁇ m was used as the separator.
  • Example 1--7 The non-aqueous electrolyte secondary battery of Example 1-7 uses the electrolytic solution E8.
  • the mixing ratio of the positive electrode active material, the conductive additive and the binder, the type of the binder for the negative electrode, the mixing ratio of the negative electrode active material and the binder The separator is the same as the nonaqueous electrolyte secondary battery of Example 1-1 except for the separator.
  • a cellulose nonwoven fabric with a thickness of 20 ⁇ m was used as the separator.
  • the nonaqueous electrolyte secondary battery of Example 1-8 uses the electrolytic solution E13.
  • the non-aqueous electrolyte secondary battery of Example 1-8 has a mixing ratio of the positive electrode active material and the conductive additive, the type of the binder for the negative electrode, the mixing ratio of the negative electrode active material and the binder, and other than the separator. These are the same as the nonaqueous electrolyte secondary battery of Example 1-1.
  • NCM523: AB: PVdF 90: 8: 2.
  • a cellulose nonwoven fabric with a thickness of 20 ⁇ m was used as the separator.
  • Comparative Example 1-1 The nonaqueous electrolyte secondary battery of Comparative Example 1-1 is the same as Example 1-1 except that the electrolytic solution C5 was used as the electrolytic solution.
  • the non-aqueous electrolyte secondary battery of Comparative Example 1-2 uses an electrolytic solution C5.
  • the non-aqueous electrolyte secondary battery of Comparative Example 1-2 is different from the electrolyte type, the mixing ratio of the positive electrode active material, the conductive additive and the binder, the mixing ratio of the negative electrode active material and the binder, and the separator. These are the same as the nonaqueous electrolyte secondary battery of Example 1-1.
  • a cellulose nonwoven fabric with a thickness of 20 ⁇ m was used as the separator.
  • the non-aqueous electrolyte secondary battery of Comparative Example 1-3 uses the electrolytic solution C5.
  • the non-aqueous electrolyte secondary battery of Comparative Example 1-3 includes the type of electrolyte, the mixing ratio of the positive electrode active material, the conductive auxiliary agent, and the binder, the type of binder for the negative electrode, and the binding with the negative electrode active material. Except for the mixing ratio with the agent and the separator, the non-aqueous electrolyte secondary battery of Example 1-1 is the same.
  • the electrolyte in the non-aqueous electrolyte secondary battery of Example 1-1 and the electrolyte in the non-aqueous electrolyte secondary battery of Example 1-2 were salted with sulfur element (S), oxygen element, and nitrogen element (N). including.
  • the electrolyte in the nonaqueous electrolyte secondary battery of Comparative Example 1-1 does not contain these in the salt.
  • the electrolyte solutions in the nonaqueous electrolyte secondary batteries of Example 1-1, Example 1-2, and Comparative Example 1-1 were all made of salt with fluorine element (F) carbon element (C) and oxygen element ( O).
  • each of the negative electrode S, O-containing film and the negative electrode film contains a component derived from the chemical structure of the anion of the metal salt (that is, the supporting salt).
  • Example 1-1 The analysis result of elemental sulfur (S) shown in FIG. 41 was analyzed in more detail.
  • peak separation was performed using a Gauss / Lorentz mixture function.
  • the analysis result of Example 1-1 is shown in FIG. 42, and the analysis result of Example 1-2 is shown in FIG.
  • the negative electrode film of Comparative Example 1-1 did not contain S exceeding the detection limit, but the negative electrode S, O-containing film of Example 1-1 and the negative electrode S, O of Example 1-2 were contained. S was detected from the film. Further, the negative electrode S, O-containing film of Example 1-1 contained more S than the negative electrode S, O-containing film of Example 1-2. Since S was not detected from the negative electrode S, O-containing film of Comparative Example 1-1, S contained in the negative electrode S, O-containing film of each example was an unavoidable impurity contained in the positive electrode active material or other It can be said that it is not derived from the additive but derived from the metal salt in the electrolytic solution.
  • the S element ratio in the negative electrode S, O-containing film of Example 1-1 was 10.4 atomic%, and the S element ratio in the negative electrode S, O-containing film in Example 1-2 was 3.7 atomic%. Therefore, in the nonaqueous electrolyte secondary battery of the present invention, the S element ratio in the negative electrode S, O-containing coating is 2.0 atomic% or more, preferably 2.5 atomic% or more, more preferably 3 It is 0.0 atomic% or more, and more preferably 3.5 atomic% or more.
  • the elemental ratio (atomic%) of S indicates the peak intensity ratio of S when the sum of the peak intensities of S, N, F, C, and O is 100% as described above.
  • the upper limit value of the element ratio of S is not particularly defined, but to be strong, it should be 25 atomic% or less.
  • FIG. 44 is a BF (Bright-field) -STEM image
  • FIGS. 45 to 47 are element distribution images by SETM-EDX in the same observation region as FIG. 45 shows the analysis result for C
  • FIG. 46 shows the analysis result for O
  • FIG. 47 shows the analysis result for S. 45 to 47 show analysis results of the negative electrode in the discharged nonaqueous electrolyte secondary battery.
  • a black portion exists in the upper left part of the STEM image. This black part is derived from Pt deposited in the pretreatment of FIB processing.
  • a portion above the Pt-derived portion (referred to as a Pt portion) can be regarded as a contaminated portion after Pt deposition. Therefore, in FIGS. 45 to 47, only the portion below the Pt portion was examined.
  • C was layered below the Pt portion. This is considered to be a layered structure of graphite as a negative electrode active material.
  • O exists in the part corresponding to the outer periphery and interlayer of graphite.
  • S exists in the part corresponding to the outer periphery and interlayer of graphite. From these results, it is surmised that the negative electrode S, O-containing film containing S and O, such as the S ⁇ O structure, is formed between the surface and the interlayer of graphite.
  • the thickness of the negative electrode S, O-containing film increases after charging. From this result, it is presumed that the negative electrode S, O-containing film has a fixing portion that stably exists with respect to charging and discharging and an adsorption portion that increases and decreases with charging and discharging. And it is estimated that the thickness of the negative electrode S, O-containing film increased or decreased during charging / discharging due to the presence of the adsorbing portion.
  • the positive electrode S, O-containing film of Example 1-1 also contains S and O.
  • the positive electrode S, O-containing film of Example 1-1 is also applied to the electrolyte solution of the present invention in the same manner as the negative electrode S, O-containing film of Example 1-1. It can be seen that it has a derived S ⁇ O structure.
  • the height of the peak existing in the vicinity of 529 eV decreases after the cycle.
  • This peak is considered to indicate the presence of O derived from the positive electrode active material.
  • photoelectrons excited by O atoms in the positive electrode active material pass through the S, O-containing coating and are detected. It is thought that it was done. Since this peak decreased after the cycle, it is considered that the thickness of the S, O-containing film formed on the positive electrode surface increased with the cycle.
  • O and S in the positive electrode S, O-containing film increased during discharging and decreased during charging. From this result, it is considered that O and S enter and leave the positive electrode S and O-containing film with charge and discharge. From this fact, the concentration of S and O in the positive electrode S and O-containing coating is increased or decreased during charging or discharging, or the presence of an adsorbing portion in the positive electrode S and O-containing coating as well as the negative electrode S and O-containing coating. It is estimated that the thickness increases or decreases.
  • the positive electrode S, O-containing coating and the negative electrode S, O-containing coating were analyzed by XPS.
  • the nonaqueous electrolyte secondary battery of Example 1-4 was set to 25 ° C., operating voltage range 3.0V to 4.1V, and CC charge / discharge was repeated 500 cycles at a rate of 1C.
  • the XPS spectrum of the positive electrode S, O-containing film was measured in a discharge state of 3.0 V and a charge state of 4.0 V.
  • the negative electrode S, O-containing coating in the 3.0V discharge state before the cycle test (that is, after the first charge / discharge) and the negative electrode S, O-containing coating in the 3.0V discharge state after 500 cycles are measured by XPS. Elemental analysis was performed, and the S element ratio contained in the negative electrode S, O-containing film was calculated.
  • Table 14 shows the S element ratio (atomic%) of the negative electrode film measured by XPS. The S element ratio was calculated in the same manner as the above-mentioned item “S element ratio of negative electrode S, O-containing film”.
  • the negative electrode S, O-containing film of Example 1-4 contained 2.0 atomic% or more of S even after the first charge / discharge and after 500 cycles. From this result, it can be seen that the negative electrode S, O-containing film in the nonaqueous electrolyte secondary battery of the present invention contains 2.0 atomic% or more of S before or after the cycle.
  • the non-aqueous electrolyte secondary batteries of Examples 1-4 to 1-7 and Comparative Examples 1-2 and 1-3 were subjected to a high-temperature storage test that was stored at 60 ° C. for one week.
  • the positive electrode S, O-containing film and negative electrode S, O-containing film of each of the examples, and the positive electrode film and negative electrode film of each comparative example were analyzed.
  • CC-CV charge was performed at a rate of 0.33 C from 3.0 V to 4.1 V.
  • the charge capacity at this time was set as a standard (SOC100), 20% of the standard was CC discharged and adjusted to SOC80, and then a high-temperature storage test was started.
  • FIG. 52 shows the analysis results for the elemental sulfur in the positive electrode S, O-containing coatings of Examples 1-4 and 1-5 and the positive electrode coating of Comparative Example 1-2.
  • FIG. 53 shows the analysis results for the elemental sulfur in the positive electrode S, O-containing coatings of Examples 1-6 and 1-7 and the positive electrode coating of Comparative Example 1-3.
  • FIG. 54 shows analysis results of oxygen elements in the positive electrode S, O-containing coatings of Examples 1-4 and 1-5 and the positive electrode coating of Comparative Example 1-2.
  • FIG. 55 shows the analysis results of oxygen elements in the positive electrode S, O-containing films of Examples 1-6 and 1-7 and the positive electrode film of Comparative Example 1-3.
  • FIG. 56 shows the analysis results of the elemental sulfur in the negative electrode S, O-containing coatings of Examples 1-4 and 1-5 and the negative electrode coating of Comparative Example 1-2.
  • FIG. 57 shows the analysis results of the elemental sulfur in the negative electrode S, O-containing coatings of Examples 1-6 and 1-7 and the negative electrode coating of Comparative Example 1-3.
  • FIG. 58 shows the results of analysis of oxygen elements in the negative electrode S, O-containing films of Examples 1-4 and 1-5 and the negative electrode film of Comparative Example 1-2.
  • FIG. 59 shows analysis results of oxygen elements in the negative electrode S, O-containing coatings of Examples 1-6 and 1-7 and the negative electrode coating of Comparative Example 1-3.
  • the nonaqueous electrolyte secondary batteries of Comparative Example 1-2 and Comparative Example 1-3 using the conventional electrolytic solution do not contain S in the positive electrode film.
  • the positive electrode S and O-containing film contained S.
  • the nonaqueous electrolyte secondary batteries of Examples 1-4 to 1-7 all contained O in the positive electrode S, O-containing film.
  • the positive electrode S, O-containing coatings in the nonaqueous electrolyte secondary batteries of Examples 1-4 to 1-7 all have SO 2 (S ⁇ O structure).
  • the nonaqueous electrolyte secondary batteries of Examples 1-4 to 1-7 also contain S and O in the negative electrode S and O-containing films, and these have an S ⁇ O structure. None and derived from the electrolyte. And it turns out that this negative electrode S and O containing film
  • the XPS spectra of the negative electrode S and O-containing films and the negative electrode films after the above high-temperature storage test and discharge were measured. Then, the ratio of the S element at the time of discharge in the negative electrode S, O-containing film of Example 1-4 and Example 1-5 and the negative electrode film of Comparative Example 1-2 was calculated. Specifically, for each negative electrode S, O-containing film or negative electrode film, the element ratio of S was calculated when the sum of the peak intensities of S, N, F, C, and O was 100%. The results are shown in Table 15.
  • the negative electrode film of Comparative Example 1-2 did not contain S exceeding the detection limit, but from the negative electrode S, O-containing films of Examples 1-4 and 1-5, S Was detected. Further, the negative electrode S, O-containing film of Example 1-5 contained more S than the negative electrode S, O-containing film of Example 1-4. Further, from this result, it is understood that the S element ratio in the negative electrode S, O-containing film is 2.0 atomic% or more even after high temperature storage.
  • Nonaqueous electrolyte secondary batteries of Example 1-4, Example 1-5, Example 1-8, and Comparative Example 1-2 were prepared, and the internal resistance of the battery was evaluated.
  • room temperature a range of 3.0 V to 4.1 V (vs. Li standard)
  • CC charge / discharge that is, constant current charge / discharge
  • AC impedance after the first charge / discharge and the AC impedance after 100 cycles were measured. Based on the obtained complex impedance plane plot, the reaction resistances of the electrolytic solution, the negative electrode, and the positive electrode were each analyzed.
  • the negative electrode reaction resistance and the positive electrode reaction resistance after 100 cycles tend to be lower than the respective resistances after the first charge / discharge.
  • the negative electrode reaction resistance and the positive electrode reaction resistance of the nonaqueous electrolyte secondary battery of each example were the negative electrode reaction resistance and the positive electrode of the nonaqueous electrolyte secondary battery of Comparative Example 1-2. Low compared to reaction resistance.
  • the nonaqueous electrolyte secondary batteries of Examples 1-4, 1-5, and 1-8 use the electrolyte solution of the present invention.
  • An S, O-containing film derived from the electrolytic solution of the invention is formed.
  • the S and O-containing coating is not formed on the surfaces of the negative electrode and the positive electrode.
  • the negative electrode reaction resistance and the positive electrode reaction resistance of Example 1-4, Example 1-5, and Example 1-8 are lower than those of the nonaqueous electrolyte secondary battery of Comparative Example 1-2. . From this, in each Example, it is guessed that the negative electrode reaction resistance and the positive electrode reaction resistance were reduced by the presence of the S, O-containing film derived from the electrolytic solution of the present invention.
  • the solution resistances of the electrolyte solutions in the nonaqueous electrolyte secondary batteries of Example 1-5 and Comparative Example 1-2 are almost the same, and the nonaqueous electrolyte secondary batteries of Example 1-4 and Example 1-8 The solution resistance of the electrolyte solution in is higher than in Example 1-5 and Comparative Example 1-2.
  • the solution resistance of each electrolyte solution in each non-aqueous electrolyte secondary battery is substantially the same after the first charge / discharge and after 100 cycles. For this reason, it is considered that the durability deterioration of each electrolytic solution does not occur, and the difference between the negative electrode reaction resistance and the positive electrode reaction resistance generated in the comparative examples and examples described above is not related to the durability deterioration of the electrolyte solution but the electrode. It is thought to have occurred in itself.
  • the internal resistance of the non-aqueous electrolyte secondary battery can be comprehensively determined from the solution resistance of the electrolytic solution, the reaction resistance of the negative electrode, and the reaction resistance of the positive electrode. Based on the results of Table 16 and Table 17, the nonaqueous electrolyte secondary batteries of Examples 1-4 and 1-8 are particularly durable from the viewpoint of suppressing the increase in internal resistance of the nonaqueous electrolyte secondary battery. It can be said that the nonaqueous electrolyte secondary battery of Example 1-5 is excellent in durability.
  • the nonaqueous electrolyte secondary batteries of Examples 1-4, 1-5, and 1-8 contain EC even though they do not contain EC as a material for SEI.
  • the capacity retention rate equivalent to that of the nonaqueous electrolyte secondary battery of Comparative Example 1-2 was shown. This is thought to be because the S and O-containing coatings derived from the electrolytic solution of the present invention are present on the positive electrode and the negative electrode in the nonaqueous electrolyte secondary battery of each example.
  • the nonaqueous electrolyte secondary battery of Example 1-4 exhibited an extremely high capacity retention rate even after the elapse of 500 cycles, and was particularly excellent in durability. From this result, it can be said that when DMC is selected as the organic solvent, the durability is further improved as compared with the case where AN is selected.
  • the remaining capacity of the nonaqueous electrolyte secondary batteries of Examples 1-4 and 1-5 is larger than the remaining capacity of the nonaqueous electrolyte secondary battery of Comparative Example 1-2. From this result, it can be said that the S, O-containing coating derived from the electrolytic solution of the present invention and formed on the positive electrode and the negative electrode contributes to an increase in the remaining capacity.
  • the electrolyte in the non-aqueous electrolyte secondary battery of the present invention is different from the conventional one, and S, O formed on the negative electrode and / or the positive electrode of the non-aqueous electrolyte secondary battery of the present invention. It is thought that the contained film is also different from the conventional film.
  • the output of the nonaqueous electrolyte secondary battery of Example 1-1 at 0 ° C. and SOC 20% was 1.2% compared to the output of the nonaqueous electrolyte secondary battery of Comparative Example 1-1. Double to 1.3 times higher.
  • the output of the nonaqueous electrolyte secondary battery of Example 1-1 at 25 ° C. and SOC 20% was 1.2% compared to the output of the nonaqueous electrolyte secondary battery of Comparative Example 1-1. Double to 1.3 times higher.
  • the nonaqueous electrolyte secondary battery of Example 1-1 had a ratio of output at 0 ° C. to output at 25 ° C. at 2 seconds output and 5 seconds output (0 ° C. output / 25 ° C. output).
  • the non-aqueous electrolyte secondary battery of Example 1-1 is almost the same as the non-aqueous electrolyte secondary battery of Comparative Example 1-1. It was found that the decrease in output at low temperatures can be suppressed.
  • the nonaqueous electrolyte secondary battery was fully charged under a charge end voltage of 4.2 V and a constant current and constant voltage condition.
  • the fully charged nonaqueous electrolyte secondary battery was disassembled and the positive electrode was taken out.
  • 3 mg of the positive electrode active material layer obtained from the positive electrode and 1.8 ⁇ L of the electrolytic solution were placed in a stainless steel pan, and the pan was sealed. Using a sealed pan, under a nitrogen atmosphere, the heating rate was 20 ° C / min.
  • the differential scanning calorimetry was performed under the conditions described above, and the DSC curve was observed.
  • a Rigaku DSC8230 was used as a differential scanning calorimeter.
  • FIG. 61 shows a DSC chart in the case where the positive electrode active material layer in the charged state of the nonaqueous electrolyte secondary battery of Example 1-1 and the electrolyte coexist.
  • FIG. 62 shows DSC charts in the case where the positive electrode active material layer in the charged state of the nonaqueous electrolyte secondary battery of Comparative Example 1-1 and the electrolyte coexist.
  • the non-aqueous electrolyte secondary battery using the electrolytic solution of the present invention is more reactive with the positive electrode active material and the electrolytic solution than the non-aqueous electrolyte secondary battery using the conventional electrolytic solution. It can be seen that it is low and has excellent thermal stability.
  • imide salts are considered to easily corrode aluminum current collectors.
  • a lithium salt such as LiPF 6
  • LiPF 6 LiPF 6 that is about four times the imide salt was blended in the electrolyte.
  • the electrolytic solution of the present invention hardly corrodes aluminum. Therefore, an aluminum current collector can be suitably used in the nonaqueous electrolyte secondary battery of the present invention.
  • a nonaqueous electrolyte secondary battery using the electrolytic solution E8 was produced as follows.
  • An aluminum foil (JIS A1000 series) having a diameter of 13.82 mm, an area of 1.5 cm 2 and a thickness of 20 ⁇ m was used as a working electrode, and the counter electrode was metal Li.
  • As the separator Whatman glass fiber filter paper having a thickness of 400 ⁇ m: No. 1825-055 was used.
  • a working electrode, a counter electrode, a separator, and an electrolyte solution of E8 were accommodated in a battery case (CR2032-type coin cell case manufactured by Hosen Co., Ltd.) to obtain a nonaqueous electrolyte secondary battery.
  • FIG. 63 shows a graph showing the relationship between the first and second, third and third currents and the electrode potential of EB4.
  • EB6 A nonaqueous electrolyte secondary battery EB6 was obtained in the same manner as EB4, except that the electrolytic solution E16 was used instead of the electrolytic solution E8.
  • EB7 A nonaqueous electrolyte secondary battery EB7 was obtained in the same manner as EB4 except that the electrolytic solution E19 was used instead of the electrolytic solution E8.
  • EB8 A nonaqueous electrolyte secondary battery EB8 was obtained in the same manner as EB4 except that the electrolytic solution E13 was used instead of the electrolytic solution E8.
  • CB4 A nonaqueous electrolyte secondary battery CB4 was obtained in the same manner as EB4 except that the electrolytic solution C5 was used instead of the electrolytic solution E8.
  • CB5 A nonaqueous electrolyte secondary battery CB5 was obtained in the same manner as EB4 except that the electrolytic solution C6 was used instead of the electrolytic solution E8.
  • the non-aqueous electrolyte secondary batteries EB4 to EB7 and CB4 were subjected to cyclic voltammetry evaluation for 5 cycles under conditions of 3.1 V to 4.6 V and 1 mV / s, and then 3.1 V to 5.1 V and 1 mV. Cyclic voltammetry was evaluated for 5 cycles under the conditions of / s.
  • 64 to 72 are graphs showing the relationship between the potential and response current for EB4 to EB7 and CB4. Further, graphs showing the relationship between the potential and response current for EB5, EB8, and CB5 are shown in FIGS.
  • the electrolytes E8, E11, E16, and E19 can be said to be suitable electrolytes for batteries using aluminum as a current collector or the like.
  • the amount of Al deposited on the negative electrode surface was significantly smaller than that of the nonaqueous electrolyte secondary battery of Comparative Example 1-1. . Therefore, in the nonaqueous electrolyte secondary batteries of Example 1-1 and Example 1-2 using the electrolytic solution of the present invention, the nonaqueous electrolyte secondary battery of Comparative Example 1-1 using the conventional electrolytic solution is used. It was found that the elution of Al from the positive electrode current collector was suppressed more than the battery.
  • Example 24 Surface analysis of Al current collector
  • the nonaqueous electrolyte secondary batteries of Example 1-1 and Example 1-2 were set to a working voltage range of 3 V to 4.2 V, charged and discharged at a rate of 1 C 100 times, disassembled after 100 times of charging and discharging, and used for the positive electrode
  • Each aluminum foil as a current collector was taken out, and the surface of the aluminum foil was washed with dimethyl carbonate.
  • the surface of the aluminum foil of the non-aqueous electrolyte secondary battery of Example 1-1 and Example 1-2 after cleaning was subjected to surface analysis by X-ray photoelectron spectroscopy (XPS) while being etched by Ar sputtering. 79 and 80 show the surface analysis results of the aluminum foil after charge / discharge of the nonaqueous electrolyte secondary batteries of Example 1-1 and Example 1-2.
  • XPS X-ray photoelectron spectroscopy
  • the surface analysis results of the aluminum foil as the positive electrode current collector of the nonaqueous electrolyte secondary batteries of Examples 1-1 and 1-2 are almost the same.
  • the chemical state of Al on the outermost surface was AlF 3 .
  • peaks of Al, O, and F were detected. It was found that the chemical state of Al was a composite state of Al—F bond and Al—O bond at the place where the aluminum foil was etched once to three times from the surface. As the etching was further continued, the O and F peaks disappeared from the fourth etching (depth about 25 nm in terms of SiO 2 ), and only the Al peak was observed.
  • AlF 3 is observed at the Al peak position 76.3 eV
  • pure Al is observed at the Al peak position 73 eV
  • Al peak position is observed.
  • the broken lines shown in FIGS. 79 and 80 show typical peak positions of AlF 3 , Al, and Al 2 O 3, respectively.
  • an Al—F bond (presumed to be AlF 3 ) layer having a thickness of about 25 nm in the depth direction is formed on the surface of the aluminum foil of the non-aqueous electrolyte secondary battery after charge / discharge of the present invention. It was confirmed that a layer in which Al—F bonds (presumed to be AlF 3 ) and Al—O bonds (presumed to be Al 2 O 3 ) were mixed was formed.
  • an Al—F bond (AlF 3) is formed on the outermost surface of the aluminum foil after charge / discharge even when the electrolyte of the present invention is used. It was found that a passive film consisting of
  • the nonaqueous electrolyte secondary battery of Example 1-4 was charged and discharged at 25 ° C. for 3 cycles, then disassembled in a 3V discharge state, and the positive electrode was taken out. Separately, the nonaqueous electrolyte secondary battery of Example 1-4 was charged and discharged for 500 cycles at 25 ° C., then disassembled in a 3V discharge state, and the positive electrode was taken out. Separately from this, the nonaqueous electrolyte secondary battery of Example 1-4 was charged and discharged at 25 ° C. for 3 cycles, then left at 60 ° C. for 1 month, disassembled in a 3 V discharge state, and the positive electrode was taken out. Each positive electrode was washed with DMC three times to obtain a positive electrode for analysis. In addition, the positive electrode S and O containing film was formed in the said positive electrode, and the structural information of the molecule
  • Each positive electrode for analysis was analyzed by TOF-SIMS.
  • a time-of-flight secondary ion mass spectrometer was used as a mass spectrometer, and positive secondary ions and negative secondary ions were measured.
  • Bi was used as the primary ion source, and the primary acceleration voltage was 25 kV.
  • Ar-GCIB Ar1500 was used as the sputter ion source.
  • Table 25 to Table 27 The measurement results are shown in Table 25 to Table 27.
  • the positive ion intensity (relative value) of each fragment is a relative value with the total positive ion intensity of all detected fragments as 100%.
  • the negative ionic strength (relative value) of each fragment described in Table 27 is a relative value where the sum of the negative ionic strengths of all the detected fragments is 100%.
  • the only fragments presumed to be derived from the solvent of the electrolytic solution were C 3 H 3 and C 4 H 3 detected as positive secondary ions.
  • a fragment presumed to be derived from a salt of the electrolytic solution is mainly detected as a negative secondary ion, and has a higher ionic strength than the above-described fragment derived from a solvent.
  • fragments containing Li are mainly detected as positive secondary ions, and the ionic strength of the fragments containing Li accounts for a large proportion of positive secondary ions and negative secondary ions.
  • the main component of the S, O-containing coating of the present invention is a component derived from the metal salt contained in the electrolytic solution, and that the S, O-containing coating of the present invention contains a large amount of Li. Is done.
  • SNO 2 , SFO 2 , S 2 F 2 NO 4, etc. are also detected as fragments presumed to be derived from salts.
  • the conventional electrolyte solution introduced in, for example, the above-mentioned JP2013-145732 that is, a conventional electrolyte solution containing EC as an organic solvent, LiPF 6 as a metal salt, and LiFSA as an additive
  • S is taken into the decomposition product of the organic solvent.
  • S is considered to exist as ions such as C p H q S (p and q are independent integers) in the negative electrode film and / or the positive electrode film.
  • the fragment containing S detected from the S, O-containing film of the present invention is not a C p H q S fragment but mainly a fragment reflecting an anion structure. It is. This also reveals that the S, O-containing coating of the present invention is fundamentally different from a coating formed on a conventional nonaqueous electrolyte secondary battery.
  • a nonaqueous electrolyte secondary battery using the electrolytic solution E8 was produced as follows. 90 parts by mass of graphite having an average particle diameter of 10 ⁇ m as an active material and 10 parts by mass of polyvinylidene fluoride as a binder were mixed. This mixture was dispersed in an appropriate amount of N-methyl-2-pyrrolidone to prepare a slurry. A copper foil having a thickness of 20 ⁇ m was prepared as a current collector. The slurry was applied in a film form on the surface of the copper foil using a doctor blade. The copper foil coated with the slurry was dried to remove N-methyl-2-pyrrolidone, and then the copper foil was pressed to obtain a bonded product.
  • the obtained joined product was heat-dried at 120 ° C. for 6 hours with a vacuum dryer to obtain a copper foil on which an active material layer was formed. This was the working electrode.
  • the mass of the active material per 1 cm 2 of copper foil was 1.48 mg.
  • the density of graphite and polyvinylidene fluoride before pressing was 0.68 g / cm 3
  • the density of the active material layer after pressing was 1.025 g / cm 3 .
  • the counter electrode was metal Li.
  • Whatman glass fiber filter paper having a thickness of 400 ⁇ m and electrolyte E8 as a separator sandwiched between the working electrode and the counter electrode are accommodated in a battery case (CR2032 type coin cell case manufactured by Hosen Co., Ltd.) with a diameter of 13.82 mm.
  • a battery case CR2032 type coin cell case manufactured by Hosen Co., Ltd.
  • EB10 A nonaqueous electrolyte secondary battery EB10 was obtained in the same manner as EB9 except that the electrolytic solution E11 was used.
  • EB11 A nonaqueous electrolyte secondary battery EB11 was obtained in the same manner as EB9 except that the electrolytic solution E16 was used.
  • EB12 A nonaqueous electrolyte secondary battery EB12 was obtained in the same manner as EB9 except that the electrolytic solution E19 was used.
  • CB6 A nonaqueous electrolyte secondary battery CB6 was obtained in the same manner as EB9 except that the electrolytic solution C5 was used.
  • Rate characteristics The rate characteristics of EB9 to EB12 and CB6 were tested by the following method. Each non-aqueous electrolyte secondary battery was charged at a rate of 0.1C, 0.2C, 0.5C, 1C, 2C, then discharged, and the capacity (discharge capacity) of the working electrode at each speed was measured. did. 1C means a current value required to fully charge or discharge the battery in one hour at a constant current. Further, in this description, the counter electrode is regarded as a negative electrode and the working electrode is regarded as a positive electrode. The ratio (rate characteristic) of the capacity at other rates to the capacity of the working electrode at the 0.1 C rate was calculated. The results are shown in Table 28.
  • EB9, EB10, EB11, and EB12 are at rates of 0.2C, 0.5C, and 1C, and EB9 and EB10 are also at a rate of 2C, compared to CB6. It was confirmed that
  • Each nonaqueous electrolyte secondary battery is CC charged (constant current charge) to 25 ° C. and a voltage of 2.0 V, and is subjected to CC discharge (constant current discharge) to a voltage of 0.01 V.
  • the discharge cycle is performed for 3 cycles at a charge / discharge rate of 0.1 C, and thereafter, 3 cycles are charged and discharged for each charge / discharge rate in the order of 0.2 C, 0.5 C, 1 C, 2 C, 5 C, and 10 C. Three cycles of charge and discharge were performed at 0.1 C.
  • Capacity maintenance rate (%) B / A ⁇ 100 A: Discharge capacity of the second working electrode in the first 0.1 C charge / discharge cycle B: Discharge capacity of the second working electrode in the last 0.1 C charge / discharge cycle Table 29 shows the results.
  • the counter electrode is regarded as a negative electrode and the working electrode is regarded as a positive electrode.
  • any of the nonaqueous electrolyte secondary batteries performed a good charge / discharge reaction and showed a suitable capacity retention rate.
  • the capacity retention rates of EB10, EB11, and EB12 were remarkably excellent.
  • EB13 A nonaqueous electrolyte secondary battery EB13 was obtained in the same manner as EB9 except that the electrolytic solution E9 was used.
  • This slurry was applied onto the surface of an electrolytic copper foil (current collector) having a thickness of 18 ⁇ m using a doctor blade, and a negative electrode active material layer was formed on the copper foil.
  • a non-aqueous electrolyte secondary battery (half cell) was prepared.
  • the counter electrode was a metal lithium foil (thickness 500 ⁇ m).
  • the counter electrode was cut to ⁇ 15 mm, the evaluation electrode was cut to ⁇ 11 mm, and a separator (Whatman glass fiber filter paper having a thickness of 400 ⁇ m) was sandwiched between them to form an electrode body battery.
  • This electrode body battery was accommodated in a battery case (CR2032 coin cell manufactured by Hosen Co., Ltd.). Then, the electrolyte solution E8 was injected, the battery case was sealed, and the nonaqueous electrolyte secondary battery of Example 2-1 was obtained. Details of the non-aqueous electrolyte secondary battery of Example 2-1 and the non-aqueous electrolyte secondary battery of each of the following examples are shown in Table 40 at the end of the column of Examples.
  • a negative electrode was produced in the same manner as in Example 2-1, and the other non-aqueous electrolyte secondary battery in Example 2-2 was obtained in the same manner as in Example 2-1.
  • Comparative Example 2-1 A negative electrode was prepared in the same manner as in Example 2-1, except that PVdF was used in the same amount as PAA in place of PAA as the binder, and the rest of Comparative Example 2-1 was performed in the same manner as in Example 2-1. A nonaqueous electrolyte secondary battery was obtained.
  • Example 2-2 A negative electrode was produced in the same manner as in Example 2-1, except that PVdF was used in the same amount as PAA instead of PAA as a binder. Using this negative electrode as an evaluation electrode, a nonaqueous electrolyte secondary battery was obtained in the same manner as in Example 2-1, except that the electrolytic solution C5 was used instead of the electrolytic solution E8.
  • Rate capacity (1) Current is passed in the direction in which lithium occlusion proceeds to the negative electrode. (2) Voltage range: 2 V ⁇ 0.01 V (vs. Li / Li + ) (3) Rate: 0.1C, 0.2C, 0.5C, 1C, 2C, 5C, 10C, 0.1C (current is stopped after reaching 0.01V) (4) 3 times for each rate (total 24 cycles)
  • Example 2-1 From the comparison between Example 2-1 and Comparative Example 2-1, the cycle capacity was compared with the combination of the electrolyte solution of the present invention and the PVdF binder by combining the electrolyte solution of the present invention with the PAA binder. It can be seen that the maintenance factor and the load characteristics on the high rate side (5C / 0.1C) are greatly improved. Since Comparative Example 2-2 has a high cycle capacity retention rate, the decrease in cycle capacity retention rate in Comparative Example 2-1 is considered to be a unique phenomenon in the combination of the electrolytic solution of the present invention and the PVdF binder. .
  • Example 2-2 the combination of the electrolytic solution of the present invention and the CMC-SBR binder was also compared with the combination of the electrolytic solution of the present invention and the PVdF binder.
  • the cycle capacity retention rate and the load characteristics on the high rate side (5C / 0.1C) are greatly improved.
  • FIG. 88 shows the initial charge / discharge curves for the nonaqueous electrolyte secondary batteries of Examples 2-1 and 2-2 and Comparative Example 2-1.
  • Example 2-1 when the charge / discharge curves on the high rate side (5C) of Example 2-1 and Comparative Example 2-1 were compared, in Example 2-1, a plateau region derived from the battery reaction was confirmed. In Comparative Example 2-1, the plateau region derived from the battery reaction could not be confirmed, and only a small charge capacity was obtained due to the mechanism of the adsorption system. From this, it is presumed that the load characteristics in Example 2-1 were improved not because the adsorption capacity increased, but because the concentration overvoltage decreased due to the lithium supply action of the PAA binder.
  • An electrolytic copper foil having a thickness of 20 ⁇ m was used as a negative electrode current collector, and the slurry was applied to the surface of the negative electrode current collector using a doctor blade to form a negative electrode active material layer on the current collector.
  • the positive electrode active material layer has a positive electrode active material, a binder, and a conductive additive.
  • NCM523 was used as the positive electrode active material
  • PVDF was used as the binder
  • AB was used as the conductive assistant.
  • the positive electrode current collector is made of an aluminum foil having a thickness of 20 ⁇ m.
  • the mass ratio of the positive electrode active material, the binder, and the conductive additive is 94: 3: 3.
  • NCM523, PVDF and AB were mixed so as to have the above mass ratio, and NMP as a solvent was added to obtain a paste-like positive electrode mixture.
  • the paste-like positive electrode mixture was applied to the surface of the positive electrode current collector using a doctor blade to form a positive electrode active material layer.
  • the positive electrode active material layer was dried at 80 ° C. for 20 minutes to remove NMP by volatilization.
  • the composite of the positive electrode active material layer and the positive electrode current collector was compressed using a roll press, and the positive electrode current collector and the positive electrode active material layer were firmly bonded.
  • the obtained joined product was heated with a vacuum dryer at 120 ° C. for 6 hours, cut into a predetermined shape, and a positive electrode was obtained.
  • a laminate type lithium ion secondary battery which is a kind of non-aqueous electrolyte secondary battery, was manufactured. Specifically, a cellulose nonwoven fabric (thickness 20 ⁇ m) was sandwiched as a separator between the positive electrode and the negative electrode to form an electrode plate group. The electrode plate group was covered with a set of two laminated films, and the three sides were sealed, and then the electrolyte solution was poured into the bag-like laminated film. Thereafter, the remaining one side was sealed to obtain a nonaqueous electrolyte secondary battery of Example 2-3 in which the four sides were hermetically sealed and the electrode plate group and the electrolyte were sealed.
  • Comparative Example 2-3 A negative electrode was produced in the same manner as in Example 2-3 except that 10% by mass of PVdF was used instead of CMC-SBR as a binder, and Comparative Example 2-3 was made in the same manner as in Example 2-3. A non-aqueous electrolyte secondary battery was obtained.
  • Comparative Example 2-4 A nonaqueous electrolyte secondary battery of Comparative Example 2-4 was obtained in the same manner as in Example 2-3 except that the electrolytic solution C5 was used instead of the electrolytic solution E8.
  • the positive electrode was produced in the same manner as the positive electrode of the nonaqueous electrolyte secondary battery in Example 2-3.
  • a nonaqueous electrolyte secondary battery of Comparative Example 2-5 was obtained in the same manner as Example 2-3 except that this positive electrode, negative electrode, and electrolytic solution C5 were used.
  • Evaluation conditions are 80% charged state (SOC), 0 ° C., 25 ° C., operating voltage range 3V-4.2V, and capacity 13.5 mAh.
  • SOC 80%, 0 ° C. is a region in which input characteristics are difficult to be obtained, for example, when used in a refrigerator room.
  • the input characteristics of Example 2-3 and Comparative Examples 2-3 and 2-4 were evaluated three times for 2-second input and 5-second input, respectively.
  • Tables 31 and 32 show the evaluation results of the input characteristics. “2-second input” in the table means an input after 2 seconds from the start of charging, and “5-second input” means an input after 5 seconds from the start of charging.
  • the electrolytic solution E8 used in Example 2-3 and Comparative Example 2-3 is abbreviated as “FSA”, and the electrolytic solution C5 used in Comparative Example 2-4 and Comparative Example 2-5. Is abbreviated as “ECPF”.
  • Example 2-3 has improved input (charging) characteristics compared to Comparative Examples 2-3 to 2-5. This is due to the combined use of the binder having a hydrophilic group (CMC-SBR) and the electrolytic solution of the present invention. In particular, it exhibits high input (charge) characteristics even at 0 ° C. It has been shown that the movement of the lithium ions in them proceeds smoothly.
  • CMC-SBR hydrophilic group
  • a negative electrode having a negative electrode active material layer weight of about 4 mg / cm 2 was formed in the same manner as in Example 2-1, except that the vacuum drying temperature was 100 ° C.
  • NCM523 was used as the positive electrode active material
  • PVDF was used as the binder
  • AB was used as the conductive assistant.
  • As the positive electrode current collector an aluminum foil having a thickness of 20 ⁇ m was used.
  • the positive electrode active material layer is 100 parts by mass
  • the mass ratio of the positive electrode active material, the conductive auxiliary agent, and the binder is 90: 8: 2.
  • a positive electrode was obtained in the same manner as in Example 2-3.
  • Example 2-4 Using the above positive electrode, negative electrode and the above-described electrolytic solution E11, a nonaqueous electrolyte secondary battery of Example 2-4 was obtained in the same manner as Example 2-3.
  • Comparative Example 2-6 A nonaqueous electrolyte secondary battery of Comparative Example 2-6 was obtained in the same manner as in Example 2-4 except that the electrolytic solution C5 was used instead of the electrolytic solution E11.
  • Example 2-4 combining a binder composed of a polymer having a hydrophilic group and the electrolytic solution of the present invention according to the present invention improves the cycle life and provides a low-resistance secondary battery. Can do.
  • Example 2-5 A negative electrode was prepared in the same manner as in Example 2-4, except that PAA was used instead of CMC-SBR so that the mass ratio of active material: binder was 90:10, and the negative electrode was used.
  • a nonaqueous electrolyte secondary battery of Example 2-5 was obtained in the same manner as Example 2-4 except for the above.
  • the capacity after high-temperature storage is improved by combining the binder composed of a polymer having a hydrophilic group and the electrolytic solution of the present invention according to the present invention.
  • the nonaqueous electrolyte secondary battery of Example 2-4 has higher coulomb efficiency and higher capacity retention than the nonaqueous electrolyte secondary battery of Comparative Example 2-6. That is, when LiFSA as a metal salt and CMC-SBR as a binder are combined, compared with a case where LiPF 6 as a metal salt and CMC-SBR as a binder are combined, a non-aqueous electrolyte 2 is used. The cycle characteristics of the secondary battery can be improved. Furthermore, in the nonaqueous electrolyte secondary battery of the present invention using a polymer having a hydrophilic group as a binder, LiFSA as a metal salt of an electrolytic solution can be preferably used.
  • the Coulomb efficiency tends to increase as side reactions (that is, reactions other than battery reactions such as electrolyte decomposition) in the negative electrode are reduced.
  • the side reaction in the negative electrode is often an irreversible reaction that irreversibly captures Li in the negative electrode, and may cause a reduction in battery capacity. For this reason, in each nonaqueous electrolyte secondary battery of Example 4, said side reaction is suppressed, As a result, it is estimated that the capacity maintenance rate at the time of 500 cycles increased.
  • the Coulomb efficiency shown in Table 35 is an average value of 500 cycles, that is, a value per cycle. Therefore, when 500 cycles are accumulated, the difference in coulomb efficiency between Example 2-4 and Comparative Example 2-6 becomes very large.
  • Comparative Example 2--7 A nonaqueous electrolyte secondary battery of Comparative Example 2-7 was obtained in the same manner as in Example 2-6 except that the electrolytic solution C5 was used.
  • Comparative Example 2-8 A nonaqueous electrolyte secondary battery of Comparative Example 2-8 was obtained in the same manner as in Example 2-7, except that the electrolytic solution C5 was used.
  • the nonaqueous electrolyte secondary battery of Example 2-6 was superior in capacity retention and coulomb efficiency compared to the nonaqueous electrolyte secondary battery of Example 2-7. From this result, it can be said that PAA is more preferable as the binder.
  • non-aqueous electrolyte secondary batteries of Examples 2-6 and 2-7 using LiFSA as the metal salt are the same as those of Comparative Examples 2-6 and 2-7 using LiPF 6 as the metal salt.
  • the initial DC resistance is low. Therefore, in order to achieve both improvement in capacity retention rate and suppression of increase in resistance, Examples 2-6 and Examples using the electrolytic solution of the present invention and a binder having a hydrophilic group as the binder are used. It can be said that the 2-7 nonaqueous electrolyte secondary battery, that is, the nonaqueous electrolyte secondary battery of the present invention is advantageous.
  • CC-CV was performed at 1 C to 3.0 V, and the remaining capacity was calculated according to the following formula based on the ratio of the discharge capacity at this time and the SOC 80 capacity before storage.
  • Remaining capacity 100 ⁇ (CC-CV discharge capacity after storage) / (SOC 80 capacity before storage) The storage capacity was calculated. The results are shown in Table 38.
  • the non-aqueous electrolyte secondary battery of Example 2-6 had a larger remaining capacity than the non-aqueous electrolyte secondary battery of Example 2-7. That is, the non-aqueous electrolyte secondary battery of Example 2-6 that combines LiFSA / AN and PAA is compared with the non-aqueous electrolyte secondary battery of Example 2-7 that combines LiFSA / AN and CMC-SBR. It was excellent in high-temperature storage characteristics.
  • the non-aqueous electrolyte secondary battery of the present invention in which the electrolytic solution of the present invention and the binder composed of a polymer having a hydrophilic group are combined is a binder composed of a normal electrolytic solution and a polymer having a hydrophilic group. It can be seen that it has a high temperature storage resistance equivalent to or higher than that of a conventional non-aqueous electrolyte secondary battery combined with an adhesive.
  • electrolytic solution of the present invention include the following electrolytic solutions.
  • the following electrolytes include those already described.
  • the electrolytic solution of the present invention was produced as follows. About 5 mL of 1,2-dimethoxyethane, an organic solvent, was placed in a flask equipped with a stir bar and a thermometer. Under stirring conditions, (CF 3 SO 2 ) 2 NLi, which is a lithium salt, was gradually added to 1,2-dimethoxyethane in the flask so as to keep the solution temperature at 40 ° C. or lower and dissolved. When about 13 g of (CF 3 SO 2 ) 2 NLi was added, the dissolution of (CF 3 SO 2 ) 2 NLi temporarily stagnated. Therefore, the flask was put into a thermostat, and the solution temperature in the flask was 50 ° C.
  • (CF 3 SO 2 ) 2 NLi was dissolved.
  • the dissolution of (CF 3 SO 2 ) 2 NLi stagnated again, so 1 drop of 1,2-dimethoxyethane was added with a pipette (CF 3 SO 2 ) 2 NLi dissolved.
  • (CF 3 SO 2 ) 2 NLi was gradually added, and the entire amount of predetermined (CF 3 SO 2 ) 2 NLi was added.
  • the resulting electrolyte was transferred to a 20 mL volumetric flask and 1,2-dimethoxyethane was added until the volume was 20 mL.
  • the obtained electrolytic solution had a volume of 20 mL, and (CF 3 SO 2 ) 2 NLi contained in this electrolytic solution was 18.38 g. This was designated as an electrolytic solution A.
  • the concentration of (CF 3 SO 2 ) 2 NLi in the electrolytic solution A was 3.2 mol / L, and the density was 1.39 g / cm 3 .
  • the density was measured at 20 ° C. The production was performed in a glove box under an inert gas atmosphere.
  • Electrolytic solution B By a method similar to that for the electrolytic solution A, an electrolytic solution B having a (CF 3 SO 2 ) 2 NLi concentration of 2.8 mol / L and a density of 1.36 g / cm 3 was produced.
  • Electrolytic solution C About 5 mL of acetonitrile, which is an organic solvent, was placed in a flask equipped with a stir bar. Under stirring conditions, (CF 3 SO 2 ) 2 NLi, which is a lithium salt, was gradually added to and dissolved in acetonitrile in the flask. The mixture was stirred overnight when the prescribed (CF 3 SO 2 ) 2 NLi was added. The resulting electrolyte was transferred to a 20 mL volumetric flask and acetonitrile was added until the volume was 20 mL. This was designated as an electrolytic solution C. The production was performed in a glove box under an inert gas atmosphere. The electrolytic solution C had a (CF 3 SO 2 ) 2 NLi concentration of 4.2 mol / L and a density of 1.52 g / cm 3 .
  • Electrolytic solution D By a method similar to that of the electrolytic solution C, an electrolytic solution D having a concentration of (CF 3 SO 2 ) 2 NLi of 3.0 mol / L and a density of 1.31 g / cm 3 was produced.
  • Electrolytic solution F The concentration of (CF 3 SO 2 ) 2 NLi is 3.2 mol / L and the density is 1.49 g / cm 3 except that dimethyl sulfoxide is used as the organic solvent. Electrolytic solution F was produced.
  • Electrolytic solution J (Electrolytic solution J) Except that acetonitrile was used as the organic solvent, an electrolytic solution J having a concentration of (FSO 2 ) 2 NLi of 5.0 mol / L and a density of 1.40 g / cm 3 in the same manner as the electrolytic solution G Manufactured.
  • Electrolytic solution K In the same manner as the electrolytic solution J, an electrolytic solution K having a concentration of (FSO 2 ) 2 NLi of 4.5 mol / L and a density of 1.34 g / cm 3 was produced.
  • Electrolytic solution L About 5 mL of dimethyl carbonate, which is an organic solvent, was placed in a flask equipped with a stir bar. Under stirring conditions, (FSO 2 ) 2 NLi, which is a lithium salt, was gradually added to dimethyl carbonate in the flask and dissolved. When (FSO 2 ) 2 NLi was added in a total amount of 14.64 g, the mixture was stirred overnight. The resulting electrolyte was transferred to a 20 mL volumetric flask and dimethyl carbonate was added until the volume was 20 mL. This was designated as an electrolytic solution L. The production was performed in a glove box under an inert gas atmosphere. The concentration of (FSO 2 ) 2 NLi in the electrolytic solution L was 3.9 mol / L, and the density of the electrolytic solution L was 1.44 g / cm 3 .
  • Electrolytic solution N About 5 mL of ethyl methyl carbonate, which is an organic solvent, was placed in a flask equipped with a stir bar. Under stirring conditions, (FSO 2 ) 2 NLi, which is a lithium salt, was gradually added to and dissolved in ethyl methyl carbonate in the flask. When 12.81 g of (FSO 2 ) 2 NLi was added in total, the mixture was stirred overnight. The obtained electrolytic solution was transferred to a 20 mL volumetric flask, and ethyl methyl carbonate was added until the volume became 20 mL. This was designated as an electrolytic solution N. The production was performed in a glove box under an inert gas atmosphere. The concentration of (FSO 2 ) 2 NLi in the electrolytic solution N was 3.4 mol / L, and the density of the electrolytic solution N was 1.35 g / cm 3 .
  • Electrolytic solution O About 5 mL of diethyl carbonate, which is an organic solvent, was placed in a flask equipped with a stirring bar. Under stirring conditions, (FSO 2 ) 2 NLi, which is a lithium salt, was gradually added to and dissolved in diethyl carbonate in the flask. When 11.37 g of the total amount of (FSO 2 ) 2 NLi was added, the mixture was stirred overnight. The resulting electrolyte was transferred to a 20 mL volumetric flask and diethyl carbonate was added until the volume was 20 mL. This was designated as an electrolytic solution O. The production was performed in a glove box under an inert gas atmosphere. The concentration of (FSO 2 ) 2 NLi in the electrolytic solution O was 3.0 mol / L, and the density of the electrolytic solution O was 1.29 g / cm 3 .
  • Table 39 shows a list of the above electrolytes.

Abstract

The purpose of the present invention is to provide a nonaqueous electrolyte secondary battery which has excellent battery characteristics, while having an SEI coating film that has a special structure. An electrolyte solution which contains an organic solvent having a hetero element and a salt wherein an alkali metal, an alkaline earth metal or aluminum serves as cations, and which satisfies Is > Io is used as the electrolyte solution of the nonaqueous electrolyte secondary battery of the present invention, and a coating film containing S and O and having an S=O structure is formed on the surface of the positive electrode and/or the surface of the negative electrode. Alternatively, the above-described electrolyte solution is used in the nonaqueous electrolyte secondary battery of the present invention, and a binder that is composed of a polymer having a hydrophilic group is used as a binder for the negative electrode.

Description

非水電解質二次電池Nonaqueous electrolyte secondary battery
 本発明は非水電解質二次電池に関する。 The present invention relates to a non-aqueous electrolyte secondary battery.
 非水電解質二次電池における負極および正極の表面には、皮膜が生成することが知られている。この皮膜はSEI(Solid Electrolyte Interphase)とも呼ばれ、電解液の還元分解物等で構成される(例えば、特許文献1参照)。以下、場合に応じて、この皮膜をSEI皮膜と略する。 It is known that a film is formed on the surfaces of the negative electrode and the positive electrode in the nonaqueous electrolyte secondary battery. This film is also referred to as SEI (Solid Electrolyte Interface), and is composed of a reductive decomposition product of an electrolytic solution (see, for example, Patent Document 1). Hereinafter, this film is abbreviated as SEI film depending on the case.
 負極表面および正極表面のSEI皮膜は、リチウムイオン等の電荷担体の通過を許容する。また、例えば負極表面のSEI皮膜は、負極表面と電解液との間に存在し、電解液の更なる還元分解抑制に寄与すると考えられている。特に黒鉛やSi系の負極活物質を用いた低電位負極には、SEI皮膜が必須だとされている。 The SEI film on the negative electrode surface and the positive electrode surface allows passage of charge carriers such as lithium ions. Further, for example, the SEI film on the negative electrode surface exists between the negative electrode surface and the electrolytic solution, and is considered to contribute to further reduction and reduction of the electrolytic solution. In particular, an SEI film is essential for a low potential negative electrode using graphite or Si-based negative electrode active material.
 SEI皮膜が存在することで電解液の継続的な分解が抑制されれば、サイクル経過後の電池の放電特性(以下、サイクル特性と呼ぶ)を向上させ得ると考えられる。しかしその一方で、従来の非水電解質二次電池において、負極表面および正極表面のSEI皮膜は必ずしも電池特性の向上に寄与するとは言えなかった。したがって、電池特性の更なる向上を可能にするSEI皮膜を持つ非水電解質二次電池の開発が望まれている。 If the continuous decomposition of the electrolytic solution is suppressed due to the presence of the SEI film, it is considered that the discharge characteristics (hereinafter referred to as cycle characteristics) of the battery after the cycle has elapsed can be improved. However, on the other hand, in the conventional non-aqueous electrolyte secondary battery, the SEI film on the negative electrode surface and the positive electrode surface did not necessarily contribute to the improvement of the battery characteristics. Therefore, it is desired to develop a non-aqueous electrolyte secondary battery having an SEI film that can further improve battery characteristics.
 他方、例えばリチウムイオン二次電池は、充放電容量が高く、高出力化が可能な二次電池である。リチウムイオン二次電池は、現在、主として携帯電子機器、ノートパソコン、電気自動車用の電源として用いられ、より小型・軽量の二次電池が求められている。特に自動車用途においては、大電流でリチウムイオン二次電池の充放電を行う必要があるため、高い入出力特性を有するリチウムイオン二次電池の開発が求められている。
 リチウムイオン二次電池は、リチウム(Li)を吸蔵および放出することができる活物質を正極および負極にそれぞれ有する。そして、両極間に封入された電解液内をリチウムイオンが移動することによって動作する。入出力特性等、リチウムイオン二次電池の電池特性を向上するには、正極および/または負極に用いられている活物質や結着剤の改良、電解液の改良などが必要となる。
On the other hand, for example, a lithium ion secondary battery is a secondary battery that has a high charge / discharge capacity and can achieve high output. Lithium ion secondary batteries are currently used mainly as power sources for portable electronic devices, notebook computers, and electric vehicles, and there is a demand for smaller and lighter secondary batteries. Particularly in automobile applications, since it is necessary to charge and discharge a lithium ion secondary battery with a large current, development of a lithium ion secondary battery having high input / output characteristics is required.
A lithium ion secondary battery has an active material capable of inserting and extracting lithium (Li) in a positive electrode and a negative electrode, respectively. Then, the lithium ion moves in the electrolytic solution sealed between both electrodes. In order to improve the battery characteristics of the lithium ion secondary battery such as the input / output characteristics, it is necessary to improve the active material and binder used in the positive electrode and / or the negative electrode, and improve the electrolytic solution.
 リチウムイオン二次電池の負極活物質としては、デンドライト析出の問題を回避するために黒鉛などの炭素材料が広く用いられている。このような負極活物質にリチウムイオンを可逆的に挿入および脱離させるために、一般的な電解液には環状エステルや鎖状エステルなど非水系のカーボネート系溶媒が用いられている。しかしカーボネート系溶媒を用いた従来の電解液においては、リチウムイオン二次電池の入出力特性の一種であるレート特性を大幅に向上させることは困難だとされていた。すなわち下記の非特許文献1~3に記載されているように、エチレンカーボネートやプロピレンカーボネートなどのカーボネート系溶媒を用いたリチウムイオン二次電池においては反応抵抗が大きい。このため、レート容量特性の改良のためには抜本的な電解液の溶媒組成の見直しが必要とされている。 As a negative electrode active material of a lithium ion secondary battery, a carbon material such as graphite is widely used in order to avoid the problem of dendrite precipitation. In order to reversibly insert and desorb lithium ions in such a negative electrode active material, a non-aqueous carbonate solvent such as a cyclic ester or a chain ester is used for a general electrolytic solution. However, in conventional electrolytes using carbonate-based solvents, it has been considered difficult to significantly improve rate characteristics, which are a kind of input / output characteristics of lithium ion secondary batteries. That is, as described in Non-Patent Documents 1 to 3 below, a lithium ion secondary battery using a carbonate-based solvent such as ethylene carbonate or propylene carbonate has a large reaction resistance. For this reason, in order to improve the rate capacity characteristics, it is necessary to fundamentally review the solvent composition of the electrolytic solution.
特開2007-19027号公報JP 2007-19027 A 特開2007-115671号公報JP 2007-115671 A 特開2003-268053号公報JP 2003-268053 A 特開2006-513554号公報JP 2006-513554 A
 本発明は上記事情を考慮してなされたものであり、電池特性に優れる非水電解質二次電池を得ることを解決すべき課題とする。 The present invention has been made in view of the above circumstances, and an object to be solved is to obtain a non-aqueous electrolyte secondary battery having excellent battery characteristics.
 非水電解質二次電池における負極および正極の表面には、皮膜が生成することが知られている。この皮膜はSEI(Solid Electrolyte Interphase)とも呼ばれ、電解液の還元分解物等で構成される。例えば、特開2007-19027号公報にも、この皮膜のことが紹介されている。以下、場合に応じて、この皮膜をSEI皮膜と略する。 It is known that a film is formed on the surfaces of the negative electrode and the positive electrode in the nonaqueous electrolyte secondary battery. This film is also called SEI (Solid Electrolyte Interface) and is composed of a reductive decomposition product of the electrolytic solution. For example, JP 2007-19027 A also introduces this film. Hereinafter, this film is abbreviated as SEI film depending on the case.
 負極表面および正極表面のSEI皮膜は、リチウムイオン等の電荷担体の通過を許容する。また、例えば負極表面のSEI皮膜は、負極表面と電解液との間に存在し、電解液の更なる還元分解抑制に寄与すると考えられている。特に黒鉛やSi系の負極活物質を用いた低電位負極には、SEI皮膜が必須だとされている。 The SEI film on the negative electrode surface and the positive electrode surface allows passage of charge carriers such as lithium ions. Further, for example, the SEI film on the negative electrode surface exists between the negative electrode surface and the electrolytic solution, and is considered to contribute to further reduction and reduction of the electrolytic solution. In particular, an SEI film is essential for a low potential negative electrode using graphite or Si-based negative electrode active material.
 SEI皮膜が存在することで電解液の継続的な分解が抑制されれば、サイクル経過後の電池の放電特性(以下、サイクル特性と呼ぶ)を向上させ得ると考えられる。しかしその一方で、従来の非水電解質二次電池において、負極表面および正極表面のSEI皮膜は必ずしも電池特性の向上に寄与するとは言えなかった。したがって、電池特性の更なる向上を可能にするSEI皮膜を持つ非水電解質二次電池の開発が望まれている。 If the continuous decomposition of the electrolytic solution is suppressed due to the presence of the SEI film, it is considered that the discharge characteristics (hereinafter referred to as cycle characteristics) of the battery after the cycle has elapsed can be improved. However, on the other hand, in the conventional non-aqueous electrolyte secondary battery, the SEI film on the negative electrode surface and the positive electrode surface did not necessarily contribute to the improvement of the battery characteristics. Therefore, it is desired to develop a non-aqueous electrolyte secondary battery having an SEI film that can further improve battery characteristics.
 本発明の発明者等は、鋭意研究の結果、従来の非水電解質二次電池においては、SEI皮膜の組成、構造、厚さによってはリチウムイオン等の電荷担体の通過性が充分でなく、SEI皮膜が非水電解質二次電池の反応抵抗増大(例えば入出力特性の低下)の原因となり得ることを見出した。そして、電解液の継続的な分解を抑制可能であり、かつ、電荷担体の透過性にも優れたSEI皮膜を持つ非水電解質二次電池の開発を目標とし、さらなる研究を進めた。その結果、特殊な電解液を用いる非水電解質二次電池において、負極表面には当該電解液に由来する特殊構造のSEI皮膜が生成することを見出した。さらに、正極表面にもまた当該電解液に由来する特殊構造のSEI皮膜が生成することを見出した。そして、当該電解液と当該電解液に由来する特殊構造のSEI皮膜とを持つ非水電解質二次電池が、寿命や入出力特性等の電池特性に優れることを見出した。 As a result of diligent research, the inventors of the present invention have found that in conventional non-aqueous electrolyte secondary batteries, the passage of charge carriers such as lithium ions is not sufficient depending on the composition, structure, and thickness of the SEI film. It has been found that the film can cause an increase in reaction resistance (for example, a decrease in input / output characteristics) of the nonaqueous electrolyte secondary battery. Further research was conducted with the goal of developing a non-aqueous electrolyte secondary battery having an SEI film that can suppress the continuous decomposition of the electrolyte and also has excellent charge carrier permeability. As a result, it was found that in a non-aqueous electrolyte secondary battery using a special electrolytic solution, an SEI film having a special structure derived from the electrolytic solution is formed on the negative electrode surface. Furthermore, it discovered that the SEI film | membrane of the special structure derived from the said electrolyte solution also produces | generates on the positive electrode surface. And it discovered that the nonaqueous electrolyte secondary battery which has the said electrolyte solution and the SEI film of the special structure derived from the said electrolyte solution is excellent in battery characteristics, such as a lifetime and an input-output characteristic.
 すなわち、上記課題を解決する本発明の非水電解質二次電池(1)は、
 正極と電解液と負極とを含み、
 前記電解液は、アルカリ金属、アルカリ土類金属またはアルミニウムをカチオンとするとともにアニオンの化学構造に硫黄元素および酸素元素を含む塩と、ヘテロ元素を有する有機溶媒とを含み、
 前記電解液の振動分光スペクトルにおける前記有機溶媒由来のピーク強度につき、前記有機溶媒本来のピークの強度をIoとし、前記ピークがシフトしたピークの強度をIsとした場合、Is>Ioであり、
 前記負極の表面に、S=O構造を有するS,O含有皮膜が形成されているものである。
That is, the nonaqueous electrolyte secondary battery (1) of the present invention that solves the above problems is
Including a positive electrode, an electrolyte and a negative electrode,
The electrolytic solution includes a salt containing an alkali metal, an alkaline earth metal or aluminum as a cation and containing a sulfur element and an oxygen element in the chemical structure of an anion, and an organic solvent having a hetero element,
Regarding the peak intensity derived from the organic solvent in the vibrational spectrum of the electrolyte solution, when the intensity of the original peak of the organic solvent is Io and the intensity of the peak shifted from the peak is Is, Is> Io,
An S, O-containing film having an S═O structure is formed on the surface of the negative electrode.
 また、上記課題を解決する本発明の非水電解質二次電池(1)は、
 正極と電解液と負極とを含み、
 前記電解液は、アルカリ金属、アルカリ土類金属またはアルミニウムをカチオンとするとともにアニオンの化学構造に硫黄元素および酸素元素を含む塩と、ヘテロ元素を有する有機溶媒とを含み、
 前記電解液の振動分光スペクトルにおける前記有機溶媒由来のピーク強度につき、前記有機溶媒本来のピークの強度をIoとし、前記ピークがシフトしたピークの強度をIsとした場合、Is>Ioであり、
 前記負極の表面と前記正極の表面のうちの少なくとも前記正極の表面に、S=O構造を有するS,O含有皮膜が形成されているものである。
Moreover, the nonaqueous electrolyte secondary battery (1) of the present invention that solves the above problems is
Including a positive electrode, an electrolyte and a negative electrode,
The electrolytic solution includes a salt containing an alkali metal, an alkaline earth metal or aluminum as a cation and containing a sulfur element and an oxygen element in the chemical structure of an anion, and an organic solvent having a hetero element,
Regarding the peak intensity derived from the organic solvent in the vibrational spectrum of the electrolyte solution, when the intensity of the original peak of the organic solvent is Io and the intensity of the peak shifted from the peak is Is, Is> Io,
An S, O-containing film having an S═O structure is formed on at least the positive electrode surface of the negative electrode surface and the positive electrode surface.
 このような非水電解質二次電池(1)は、負極表面および/または正極表面に特殊構造のSEI皮膜、つまりS,O含有皮膜を持ち、電池特性に優れる。 Such a nonaqueous electrolyte secondary battery (1) has an SEI film having a special structure on the negative electrode surface and / or the positive electrode surface, that is, an S, O-containing film, and is excellent in battery characteristics.
 他方、一般的な負極は、負極活物質と結着剤とを含むスラリーを集電体に塗布し、乾燥することにより作製される。結着剤には負極活物質間の結着および活物質と集電体間の結着を担う役割や、負極活物質を覆い保護する役割がある。 On the other hand, a general negative electrode is produced by applying a slurry containing a negative electrode active material and a binder to a current collector and drying it. The binder has a role of binding between the negative electrode active materials and binding between the active material and the current collector, and a role of covering and protecting the negative electrode active material.
 従来使用されている負極用結着剤としては、ポリフッ化ビニリデン(PVdF)などの含フッ素系ポリマー、カルボキシメチルセルロース(CMC)などの水溶性セルロース誘導体、ポリアクリル酸などがある。例えば上記した特許文献2には、ポリアクリル酸およびポリメタクリル酸よりなる群から選ばれるポリマーを含有し、そのポリマーは酸無水物基を含むリチウムイオン二次電池用負極が記載されている。また上記した特許文献3には、アクリル酸とメタクリル酸とを共重合させて得られるポリマーを負極用結着剤または正極用結着剤として用いることが記載されている。さらに上記した特許文献4には、アクリルアミドとアクリル酸とイタコン酸とを共重合させて得られるポリマーを負極用結着剤または正極用結着剤として用いることが記載されている。 Conventionally used binders for negative electrodes include fluorine-containing polymers such as polyvinylidene fluoride (PVdF), water-soluble cellulose derivatives such as carboxymethyl cellulose (CMC), and polyacrylic acid. For example, Patent Document 2 described above describes a negative electrode for a lithium ion secondary battery containing a polymer selected from the group consisting of polyacrylic acid and polymethacrylic acid, and the polymer includes an acid anhydride group. Patent Document 3 described above describes that a polymer obtained by copolymerizing acrylic acid and methacrylic acid is used as a negative electrode binder or a positive electrode binder. Further, Patent Document 4 described above describes that a polymer obtained by copolymerizing acrylamide, acrylic acid and itaconic acid is used as a negative electrode binder or a positive electrode binder.
 上記課題を解決する本発明の非水電解質二次電池(2)の特徴は、
 アルカリ金属、アルカリ土類金属またはアルミニウムをカチオンとする塩と、ヘテロ元素を有する有機溶媒とを含み、振動分光スペクトルにおける前記有機溶媒由来のピーク強度につき、前記有機溶媒本来のピークの強度をIoとし、前記ピークがシフトしたピークの強度をIsとした場合、Is>Ioである電解液と、親水基を有するポリマーからなる結着剤を含む負極活物質層をもつ負極と、を具備することにある。
The feature of the nonaqueous electrolyte secondary battery (2) of the present invention that solves the above problems is as follows.
Including a salt having alkali metal, alkaline earth metal or aluminum as a cation and an organic solvent having a hetero element, the peak intensity derived from the organic solvent in a vibrational spectrum is defined as Io. In the case where Is is the intensity of the peak where the peak is shifted, Is> Io, and a negative electrode having a negative electrode active material layer containing a binder composed of a polymer having a hydrophilic group. is there.
 本発明の非水電解質二次電池(2)は、負極用の結着剤として親水基を有するポリマーを用いるとともに、電解液として本発明の電解液を用いたものである。負極用の結着剤としてポリフッ化ビニリデンなどのポリマーを用いた場合には、同じ本発明の電解液を用いても、レート特性の向上とサイクル特性の向上とを両立するのは困難であった。しかし、負極用結着剤として親水基を有するポリマーからなる結着剤を用いることで、レート特性の向上とサイクル特性の向上との両立が可能となる。その理由として、例えば非水電解質二次電池がリチウムイオン二次電池であれば、結着剤に含まれるカルボキシル基などの極性基がリチウムイオンを引きつけるため、濃度過電圧が支配的となる高レート側で負荷特性が向上することが考えられる。また結着剤による活物質保護作用によってサイクル特性が向上すると考えられる。 The nonaqueous electrolyte secondary battery (2) of the present invention uses a polymer having a hydrophilic group as a binder for a negative electrode, and uses the electrolytic solution of the present invention as an electrolytic solution. When a polymer such as polyvinylidene fluoride is used as the binder for the negative electrode, it is difficult to achieve both improved rate characteristics and improved cycle characteristics even when the same electrolytic solution of the present invention is used. . However, by using a binder made of a polymer having a hydrophilic group as the negative electrode binder, it is possible to improve both the rate characteristics and the cycle characteristics. For example, if the non-aqueous electrolyte secondary battery is a lithium ion secondary battery, polar groups such as carboxyl groups contained in the binder attract lithium ions, so the concentration overvoltage becomes dominant. It is conceivable that the load characteristics are improved. Further, it is considered that the cycle characteristics are improved by the active material protecting action by the binder.
 つまり、このような非水電解質二次電池(2)によると、電解液と結着剤との最適な組み合わせによってレート容量特性の向上を図るとともに、サイクル特性も改良することができる。 That is, according to such a non-aqueous electrolyte secondary battery (2), it is possible to improve rate capacity characteristics and improve cycle characteristics by an optimal combination of the electrolytic solution and the binder.
 以下、必要に応じて、「アルカリ金属、アルカリ土類金属またはアルミニウムをカチオンとする塩と、ヘテロ元素を有する有機溶媒とを含み、振動分光スペクトルにおける前記有機溶媒由来のピーク強度につき、前記有機溶媒本来のピークの強度をIoとし、前記ピークがシフトしたピークの強度をIsとした場合、Is>Ioである電解液」を、「本発明の電解液」ということがある。
 さらに、上記した本発明の電解液のなかで、塩のアニオンの化学構造に硫黄元素および酸素元素を含むものを、特に、「電解液(1)」または「本発明の電解液(1)」ということがある。本発明の電解液(1)は本発明の電解液の一種であり、上記非水電解質二次電池(1)に含まれる。勿論、非水電解質二次電池(2)が本発明の電解液(1)を含んでも良い。
 さらに、必要に応じて、非水電解質二次電池(1)および非水電解質二次電池(2)を総称して本発明の非水電解質二次電池と呼ぶ。
Hereinafter, if necessary, “the organic solvent contains a salt having alkali metal, alkaline earth metal or aluminum as a cation and an organic solvent having a hetero element, and the peak intensity derived from the organic solvent in a vibrational spectroscopic spectrum. When the original peak intensity is Io and the peak shifted intensity is Is, the “electrolytic solution with Is> Io” may be referred to as the “electrolytic solution of the present invention”.
Furthermore, among the above-described electrolytic solutions of the present invention, those containing a sulfur element and an oxygen element in the chemical structure of the anion of the salt, particularly “electrolytic solution (1)” or “electrolytic solution of the present invention (1)”. There is. The electrolytic solution (1) of the present invention is a kind of the electrolytic solution of the present invention, and is included in the nonaqueous electrolyte secondary battery (1). Of course, the nonaqueous electrolyte secondary battery (2) may contain the electrolytic solution (1) of the present invention.
Furthermore, if necessary, the nonaqueous electrolyte secondary battery (1) and the nonaqueous electrolyte secondary battery (2) are collectively referred to as the nonaqueous electrolyte secondary battery of the present invention.
 本発明の非水電解質二次電池は電池特性に優れる。 The nonaqueous electrolyte secondary battery of the present invention is excellent in battery characteristics.
電解液E3のIRスペクトルである。It is IR spectrum of the electrolyte solution E3. 電解液E4のIRスペクトルである。It is IR spectrum of the electrolyte solution E4. 電解液E7のIRスペクトルである。It is IR spectrum of the electrolyte solution E7. 電解液E8のIRスペクトルである。It is IR spectrum of the electrolyte solution E8. 電解液E10のIRスペクトルである。It is IR spectrum of the electrolyte solution E10. 電解液C2のIRスペクトルである。It is IR spectrum of the electrolyte solution C2. 電解液C4のIRスペクトルである。It is IR spectrum of the electrolyte solution C4. アセトニトリルのIRスペクトルである。It is IR spectrum of acetonitrile. (CFSONLiのIRスペクトルである。It is an IR spectrum of (CF 3 SO 2 ) 2 NLi. (FSONLiのIRスペクトルである。 (FSO 2) is an IR spectrum of 2 NLi. 電解液E11のIRスペクトルである。It is IR spectrum of the electrolyte solution E11. 電解液E12のIRスペクトルである。It is IR spectrum of the electrolyte solution E12. 電解液E13のIRスペクトルである。It is IR spectrum of the electrolyte solution E13. 電解液E14のIRスペクトルである。It is IR spectrum of the electrolyte solution E14. 電解液E15のIRスペクトルである。It is IR spectrum of the electrolyte solution E15. 電解液C6のIRスペクトルである。It is IR spectrum of the electrolyte solution C6. ジメチルカーボネートのIRスペクトルである。It is IR spectrum of dimethyl carbonate. 電解液E16のIRスペクトルである。It is IR spectrum of the electrolyte solution E16. 電解液E17のIRスペクトルである。It is IR spectrum of the electrolyte solution E17. 電解液E18のIRスペクトルである。It is IR spectrum of the electrolyte solution E18. 電解液C7のIRスペクトルである。It is IR spectrum of the electrolyte solution C7. エチルメチルカーボネートのIRスペクトルである。It is IR spectrum of ethyl methyl carbonate. 電解液E19のIRスペクトルである。It is IR spectrum of the electrolyte solution E19. 電解液E20のIRスペクトルである。It is IR spectrum of the electrolyte solution E20. 電解液E21のIRスペクトルである。It is IR spectrum of the electrolyte solution E21. 電解液C8のIRスペクトルである。It is IR spectrum of the electrolyte solution C8. ジエチルカーボネートのIRスペクトルである。It is IR spectrum of diethyl carbonate. (FSONLiのIRスペクトルである(1900~1600cm-1)。It is an IR spectrum of (FSO 2 ) 2 NLi (1900-1600 cm −1 ). 電解液E8のラマンスペクトルである。It is a Raman spectrum of the electrolyte solution E8. 電解液E9のラマンスペクトルである。It is a Raman spectrum of the electrolyte solution E9. 電解液C4のラマンスペクトルである。It is a Raman spectrum of the electrolyte solution C4. 電解液E11のラマンスペクトルである。It is a Raman spectrum of the electrolyte solution E11. 電解液E13のラマンスペクトルである。It is a Raman spectrum of the electrolyte solution E13. 電解液E15のラマンスペクトルである。It is a Raman spectrum of the electrolyte solution E15. 電解液C6のラマンスペクトルである。It is a Raman spectrum of the electrolyte solution C6. 評価例8の急速充放電の繰り返しに対する応答性の結果である。It is a result of the responsiveness with respect to repetition of the rapid charge / discharge of Evaluation Example 8. 評価例12における、実施例1-1、実施例1-2および比較例1-1の負極S,O含有皮膜の炭素元素についてのXPS分析結果である。FIG. 10 is an XPS analysis result of carbon elements of negative electrode S and O-containing coatings of Example 1-1, Example 1-2, and Comparative Example 1-1 in Evaluation Example 12. FIG. 評価例12における、実施例1-1、実施例1-2および比較例1-1の負極S,O含有皮膜のフッ素元素についてのXPS分析結果である。7 shows the results of XPS analysis of fluorine elements in negative electrode S and O-containing films of Example 1-1, Example 1-2, and Comparative Example 1-1 in Evaluation Example 12. 評価例12における、実施例1-1、実施例1-2および比較例1-1の負極S,O含有皮膜の窒素元素についてのXPS分析結果である。7 is an XPS analysis result of nitrogen element in negative electrode S, O-containing coatings of Example 1-1, Example 1-2, and Comparative Example 1-1 in Evaluation Example 12. 評価例12における、実施例1-1、実施例1-2および比較例1-1の負極S,O含有皮膜の酸素元素についてのXPS分析結果である。7 is an XPS analysis result of oxygen elements in negative electrode S and O-containing films of Example 1-1, Example 1-2, and Comparative Example 1-1 in Evaluation Example 12. 評価例12における、実施例1-1、実施例1-2および比較例1-1の負極S,O含有皮膜の硫黄元素についてのXPS分析結果である。FIG. 10 shows the XPS analysis results for sulfur element in the negative electrode S, O-containing coatings of Example 1-1, Example 1-2, and Comparative Example 1-1 in Evaluation Example 12. FIG. 評価例12における実施例1-1の負極S,O含有皮膜のXPS分析結果である。10 is an XPS analysis result of a negative electrode S, O-containing film of Example 1-1 in Evaluation Example 12. 評価例12における実施例1-2の負極S,O含有皮膜のXPS分析結果である。7 is an XPS analysis result of a negative electrode S, O-containing film of Example 1-2 in Evaluation Example 12. 評価例12における実施例1-1の負極S,O含有皮膜のBF-STEM像である。14 is a BF-STEM image of a negative electrode S, O-containing film of Example 1-1 in Evaluation Example 12. 評価例12における、実施例1-1の負極S,O含有皮膜のCについてのSTEM分析結果である。14 is a STEM analysis result on C of the negative electrode S, O-containing film of Example 1-1 in Evaluation Example 12. 評価例12における、実施例1-1の負極S,O含有皮膜のOについてのSTEM分析結果である。FIG. 10 shows STEM analysis results for O of the negative electrode S, O-containing film of Example 1-1 in Evaluation Example 12. FIG. 評価例12における、実施例1-1の負極S,O含有皮膜のSについてのSTEM分析結果である。FIG. 10 shows STEM analysis results for S of the negative electrode S, O-containing film of Example 1-1 in Evaluation Example 12. FIG. 評価例12における、実施例1-1の正極S,O含有皮膜のOについてのXPS分析結果である。10 is an XPS analysis result on O of the positive electrode S, O-containing film of Example 1-1 in Evaluation Example 12. 評価例12における、実施例1-1の正極S,O含有皮膜のSについてのXPS分析結果である。7 is an XPS analysis result for S of the positive electrode S, O-containing film of Example 1-1 in Evaluation Example 12. 評価例12における、実施例1-4の正極S,O含有皮膜のSについてのXPS分析結果である。7 is an XPS analysis result for S of the positive electrode S, O-containing film of Example 1-4 in Evaluation Example 12. 評価例12における、実施例1-4の正極S,O含有皮膜のOについてのXPS分析結果である。7 is an XPS analysis result for O of the positive electrode S, O-containing film of Example 1-4 in Evaluation Example 12. 評価例12における、実施例1-4、実施例1-5および比較例1-2の正極S,O含有皮膜のSについてのXPS分析結果である。FIG. 10 shows the XPS analysis results for S of the positive electrode S and O-containing coatings of Example 1-4, Example 1-5, and Comparative Example 1-2 in Evaluation Example 12. FIG. 評価例12における、実施例1-6、実施例1-7および比較例1-3の正極S,O含有皮膜のSについてのXPS分析結果である。7 is an XPS analysis result on S of positive electrode S and O-containing coatings of Example 1-6, Example 1-7 and Comparative Example 1-3 in Evaluation Example 12. 評価例12における、実施例1-4、実施例1-5および比較例1-2の正極S,O含有皮膜のOについてのXPS分析結果である。10 is an XPS analysis result for O of the positive electrode S, O-containing coatings of Example 1-4, Example 1-5, and Comparative Example 1-2 in Evaluation Example 12. 評価例12における、実施例1-6、実施例1-7および比較例1-3の正極S,O含有皮膜のOについての分析結果である。7 shows the analysis results for O in the positive electrode S, O-containing coatings of Examples 1-6, 1-7, and Comparative Example 1-3 in Evaluation Example 12. 評価例12における、実施例1-4、実施例1-5および比較例1-2の負極S,O含有皮膜のSについての分析結果である。7 shows the analysis results for S of negative electrode S and O-containing films of Example 1-4, Example 1-5, and Comparative Example 1-2 in Evaluation Example 12. 評価例12における、実施例1-6、実施例1-7および比較例1-3の負極S,O含有皮膜のSについての分析結果である。7 shows the analysis results for S of negative electrode S and O-containing films of Example 1-6, Example 1-7, and Comparative Example 1-3 in Evaluation Example 12. 評価例12における、実施例1-4、実施例1-5および比較例1-2の負極S,O含有皮膜のOについての分析結果である。FIG. 10 shows the analysis results of O in the negative electrode S and O-containing coatings of Example 1-4, Example 1-5, and Comparative Example 1-2 in Evaluation Example 12. FIG. 評価例12における、実施例1-6、実施例1-7および比較例1-3の負極S,O含有皮膜のOについての分析結果である。7 shows the analysis results for O in the negative electrode S, O-containing coatings of Example 1-6, Example 1-7, and Comparative Example 1-3 in Evaluation Example 12. 評価例13における、電池の複素インピーダンス平面プロットである。It is a complex impedance plane plot of the battery in the evaluation example 13. 評価例20における、実施例1-1の非水電解質二次電池のDSCチャートである。14 is a DSC chart of the nonaqueous electrolyte secondary battery of Example 1-1 in Evaluation Example 20. 評価例20における、比較例1-1の非水電解質二次電池のDSCチャートである。18 is a DSC chart of the nonaqueous electrolyte secondary battery in Comparative Example 1-1 in Evaluation Example 20. 評価例21におけるEB4の電流と電極電位との関係を示すグラフである。It is a graph which shows the relationship between the electric current of EB4 in evaluation example 21, and electrode potential. 評価例22におけるEB4に対する電位(3.1~4.6V)と応答電流との関係を示すグラフである。22 is a graph showing a relationship between a potential (3.1 to 4.6 V) with respect to EB4 and a response current in Evaluation Example 22. 評価例22におけるEB4に対する電位(3.1~5.1V)と応答電流との関係を示すグラフである。14 is a graph showing a relationship between a potential (3.1 to 5.1 V) and a response current with respect to EB4 in Evaluation Example 22. 評価例22におけるEB5に対する電位(3.1~4.6V)と応答電流との関係を示すグラフである。14 is a graph showing a relationship between a potential (3.1 to 4.6 V) with respect to EB5 and a response current in Evaluation Example 22. 評価例22におけるEB5に対する電位(3.1~5.1V)と応答電流との関係を示すグラフである。14 is a graph showing a relationship between a potential (3.1 to 5.1 V) with respect to EB5 and a response current in Evaluation Example 22. 評価例22におけるEB6に対する電位(3.1~4.6V)と応答電流との関係を示すグラフである。22 is a graph showing a relationship between a potential (3.1 to 4.6 V) with respect to EB6 and a response current in Evaluation Example 22. 評価例22におけるEB6に対する電位(3.1~5.1V)と応答電流との関係を示すグラフである。22 is a graph showing a relationship between a potential (3.1 to 5.1 V) with respect to EB6 and a response current in Evaluation Example 22. 評価例22におけるEB7に対する電位(3.1~4.6V)と応答電流との関係を示すグラフである。14 is a graph showing a relationship between a potential (3.1 to 4.6 V) with respect to EB7 and a response current in Evaluation Example 22. 評価例22におけるEB7に対する電位(3.1~5.1V)と応答電流との関係を示すグラフである。14 is a graph showing a relationship between a potential (3.1 to 5.1 V) and a response current with respect to EB7 in Evaluation Example 22. 評価例22におけるCB4に対する電位(3.1~4.6V)と応答電流との関係を示すグラフである。14 is a graph showing a relationship between a potential (3.1 to 4.6 V) and response current with respect to CB4 in Evaluation Example 22. 評価例22におけるEB5に対する電位(3.0~4.5V)と応答電流との関係を示すグラフである。なお、図73は図66の縦軸の縮尺をかえたものである。14 is a graph showing a relationship between a potential (3.0 to 4.5 V) with respect to EB5 and a response current in Evaluation Example 22. FIG. 73 is obtained by changing the scale of the vertical axis in FIG. 評価例22におけるEB5に対する電位(3.0~5.0V)と応答電流との関係を示すグラフである。なお、図74は図67の縦軸の縮尺をかえたものである。14 is a graph showing a relationship between a potential (3.0 to 5.0 V) with respect to EB5 and a response current in Evaluation Example 22. 74 is obtained by changing the scale of the vertical axis in FIG. 評価例22におけるEB8に対する電位(3.0~4.5V)と応答電流との関係を示すグラフである。14 is a graph showing a relationship between a potential (3.0 to 4.5 V) with respect to EB8 and a response current in Evaluation Example 22. 評価例22におけるEB8に対する電位(3.0~5.0V)と応答電流との関係を示すグラフである。14 is a graph showing a relationship between a potential (3.0 to 5.0 V) with respect to EB8 and a response current in Evaluation Example 22. 評価例22におけるCB5に対する電位(3.0~4.5V)と応答電流との関係を示すグラフである。14 is a graph showing a relationship between a potential (3.0 to 4.5 V) and a response current with respect to CB5 in Evaluation Example 22. 評価例22におけるCB5に対する電位(3.0~5.0V)と応答電流との関係を示すグラフである。14 is a graph showing a relationship between a potential (3.0 to 5.0 V) and a response current with respect to CB5 in Evaluation Example 22. 評価例24における、実施例1-1の非水電解質二次電池の充放電後のアルミニウム箔の表面分析結果である。18 is a surface analysis result of an aluminum foil after charging and discharging of the nonaqueous electrolyte secondary battery of Example 1-1 in Evaluation Example 24. 評価例24における、実施例1-2の非水電解質二次電池の充放電後のアルミニウム箔の表面分析結果である。18 shows the surface analysis results of the aluminum foil after charge / discharge of the nonaqueous electrolyte secondary battery of Example 1-2 in Evaluation Example 24. EB9の充放電曲線である。It is a charging / discharging curve of EB9. EB10の充放電曲線である。It is a charging / discharging curve of EB10. EB11の充放電曲線である。It is a charging / discharging curve of EB11. EB12の充放電曲線である。It is a charging / discharging curve of EB12. CB6の充放電曲線である。It is a charging / discharging curve of CB6. 評価例29の低温レート特性の結果である。It is a result of the low-temperature rate characteristic of the evaluation example 29. 評価例29の低温レート特性の結果である。It is a result of the low-temperature rate characteristic of the evaluation example 29. 実施例2-1、2-2および比較例2-1の非水電解質二次電池の充放電特性を示すグラフである。6 is a graph showing charge / discharge characteristics of nonaqueous electrolyte secondary batteries of Examples 2-1 and 2-2 and Comparative Example 2-1.
 以下に、本発明を実施するための形態を説明する。なお、特に断らない限り、本明細書に記載された数値範囲「a~b」は、下限aおよび上限bをその範囲に含む。そして、これらの上限値および下限値、ならびに実施例中に列記した数値も含めてそれらを任意に組み合わせることで数値範囲を構成し得る。さらに数値範囲内から任意に選択した数値を上限、下限の数値とすることができる。 Hereinafter, modes for carrying out the present invention will be described. Unless otherwise specified, the numerical range “a to b” described in this specification includes the lower limit “a” and the upper limit “b”. The numerical range can be configured by arbitrarily combining these upper limit value and lower limit value and the numerical values listed in the examples. Furthermore, numerical values arbitrarily selected from the numerical value range can be used as upper and lower numerical values.
 本発明の非水電解質二次電池(1)は、負極と、正極と、本発明の電解液(1)とを含み、正極および/または負極の表面にS,O含有皮膜が形成されたものである。また、本発明の非水電解質二次電池(2)は、本発明の電解液と、親水基を有するポリマーからなる結着剤を含む負極活物質層をもつ負極と、を含む。 The nonaqueous electrolyte secondary battery (1) of the present invention includes a negative electrode, a positive electrode, and the electrolytic solution (1) of the present invention, and an S, O-containing film is formed on the surface of the positive electrode and / or the negative electrode. It is. Moreover, the nonaqueous electrolyte secondary battery (2) of the present invention includes the electrolytic solution of the present invention and a negative electrode having a negative electrode active material layer containing a binder made of a polymer having a hydrophilic group.
 本発明の非水電解質二次電池(1)は、上述したように、正極および/または負極の表面にS,O含有皮膜を形成し、電池特性の向上を図るものである。したがって、非水電解質二次電池(1)においては電解液以外の電池構成要素、例えば負極活物質、正極活物質,導電助剤、結着剤、集電体およびセパレータ等については特に限定しない。また、本発明の非水電解質二次電池(2)は、上述したように、負極用結着剤と電解液との最適な組み合わせによって電池特性の向上を図るものである。したがって、非水電解質二次電池(2)においては負極用結着剤および電解液以外の電池構成要素は特に限定しない。何れの場合にも、本発明の非水電解質二次電池における負極表面および/または正極表面には特殊構造のSEI皮膜であるS,O含有皮膜が形成される。
 また、本発明の非水電解質二次電池における電荷担体もまた特に限定しない。例えば、本発明の非水電解質二次電池はリチウムを電荷担体とする非水電解質二次電池(例えば、リチウム二次電池、リチウムイオン二次電池)であっても良いし、ナトリウムを電荷担体とする非水電解質二次電池(例えば、ナトリウム二次電池、ナトリウムイオン二次電池)であっても良い。
As described above, the nonaqueous electrolyte secondary battery (1) of the present invention is intended to improve battery characteristics by forming an S, O-containing film on the surface of the positive electrode and / or the negative electrode. Therefore, in the nonaqueous electrolyte secondary battery (1), battery constituent elements other than the electrolyte, such as a negative electrode active material, a positive electrode active material, a conductive additive, a binder, a current collector, and a separator, are not particularly limited. In addition, as described above, the nonaqueous electrolyte secondary battery (2) of the present invention is intended to improve battery characteristics by an optimal combination of a negative electrode binder and an electrolytic solution. Accordingly, in the non-aqueous electrolyte secondary battery (2), battery constituent elements other than the negative electrode binder and the electrolytic solution are not particularly limited. In any case, an S, O-containing film, which is a SEI film having a special structure, is formed on the negative electrode surface and / or the positive electrode surface in the nonaqueous electrolyte secondary battery of the present invention.
Moreover, the charge carrier in the nonaqueous electrolyte secondary battery of the present invention is not particularly limited. For example, the nonaqueous electrolyte secondary battery of the present invention may be a nonaqueous electrolyte secondary battery using lithium as a charge carrier (for example, a lithium secondary battery or a lithium ion secondary battery), or sodium as a charge carrier. It may be a non-aqueous electrolyte secondary battery (for example, a sodium secondary battery or a sodium ion secondary battery).
 上述したとおり、本発明の電解液は、アルカリ金属、アルカリ土類金属またはアルミニウムをカチオンとする塩とヘテロ原子を有する有機溶媒とを含み、振動分光スペクトルにおける有機溶媒由来のピーク強度につき、有機溶媒本来のピークの強度をIoとし、有機溶媒本来のピークが波数シフトしたピークの強度をIsとした場合、Is>Ioである。また、このうち、非水電解質二次電池(1)に用いられる電解液(1)は、塩として、アルカリ金属、アルカリ土類金属またはアルミニウムをカチオンとするとともにアニオンの化学構造に硫黄元素および酸素元素を含む塩を用いたものである。つまり、電解液(1)は本発明の電解液の一形態である。したがって本発明の電解液であれば、IoとIsとの関係は常にIs>Ioである。これに対して従来の電解液は、IsとIoとの関係がIs<Ioである。この点で本発明の電解液と従来の電解液とは大きく異なる。以下、必要に応じて、本発明の電解液および/または電解液(1)に含まれる塩、すなわち、「アルカリ金属、アルカリ土類金属またはアルミニウムをカチオンとする塩」および/または「アルカリ金属、アルカリ土類金属またはアルミニウムをカチオンとするとともにアニオンの化学構造に硫黄元素および酸素元素を含む塩」を「金属塩」、支持塩、支持電解質、または単に「塩」ということがある。なお、電解液(1)は本発明の電解液の一形態であるため、特に説明やことわりなく「本発明の電解液」について説明している箇所については、電解液(1)を含む本発明の電解液全般について説明しているものとする。 As described above, the electrolytic solution of the present invention contains a salt having a cation of alkali metal, alkaline earth metal or aluminum as a cation and an organic solvent having a hetero atom, and the organic solvent has a peak intensity derived from the organic solvent in the vibrational spectrum. When the intensity of the original peak is Io and the intensity of the peak obtained by wave number shifting of the original peak of the organic solvent is Is, Is> Io. Among these, the electrolyte solution (1) used for the nonaqueous electrolyte secondary battery (1) has an alkali metal, alkaline earth metal, or aluminum as a cation as a salt and a chemical structure of an anion with elemental sulfur and oxygen. A salt containing an element is used. That is, the electrolytic solution (1) is an embodiment of the electrolytic solution of the present invention. Therefore, in the electrolytic solution of the present invention, the relationship between Io and Is is always Is> Io. On the other hand, in the conventional electrolytic solution, the relationship between Is and Io is Is <Io. In this respect, the electrolytic solution of the present invention is greatly different from the conventional electrolytic solution. Hereinafter, if necessary, a salt contained in the electrolytic solution and / or electrolytic solution (1) of the present invention, that is, a “salt having an alkali metal, alkaline earth metal or aluminum as a cation” and / or “alkaline metal, A salt containing an alkaline earth metal or aluminum as a cation and containing an element of sulfur and oxygen in the chemical structure of the anion may be referred to as a “metal salt”, a supporting salt, a supporting electrolyte, or simply “salt”. In addition, since electrolyte solution (1) is one form of the electrolyte solution of the present invention, the portion describing “electrolyte solution of the present invention” without any particular explanation is the present invention including electrolyte solution (1). It is assumed that the general electrolyte solution is described.
 〔金属塩〕
 本発明の電解液における金属塩は、通常、電池の電解液に含まれるLiClO、LiAsF、LiPF、LiBF、LiAlCl、などの電解質として用いられる化合物であれば良い。金属塩のカチオンとしては、リチウム、ナトリウム、カリウムなどのアルカリ金属、ベリリウム、マグネシウム、カルシウム、ストロンチウム、バリウムなどのアルカリ土類金属、およびアルミニウムを挙げることができる。金属塩のカチオンは、電解液を使用する電池の電荷担体と同一の金属イオンであるのが好ましい。例えば、本発明の電解液をリチウムイオン二次電池用の電解液として使用するのであれば、金属塩のカチオンはリチウムが好ましい。
[Metal salt]
The metal salt in the electrolytic solution of the present invention may be a compound that is usually used as an electrolyte such as LiClO 4 , LiAsF 6 , LiPF 6 , LiBF 4 , LiAlCl 4 , etc. contained in the electrolytic solution of the battery. Examples of the cation of the metal salt include alkali metals such as lithium, sodium and potassium, alkaline earth metals such as beryllium, magnesium, calcium, strontium and barium, and aluminum. The cation of the metal salt is preferably the same metal ion as the charge carrier of the battery using the electrolytic solution. For example, if the electrolytic solution of the present invention is used as an electrolytic solution for a lithium ion secondary battery, the metal salt cation is preferably lithium.
 この場合、塩のアニオンの化学構造は、ハロゲン、ホウ素、窒素、酸素、硫黄または炭素から選択される少なくとも1つの元素を含むと良い。ハロゲンまたはホウ素を含むアニオンの化学構造を具体的に例示すると、ClO、PF、AsF、SbF、TaF、BF、SiF、B(C、B(oxalate)、Cl、Br、Iを挙げることができる。 In this case, the chemical structure of the anion of the salt may contain at least one element selected from halogen, boron, nitrogen, oxygen, sulfur or carbon. Specific examples of the chemical structure of an anion containing halogen or boron include ClO 4 , PF 6 , AsF 6 , SbF 6 , TaF 6 , BF 4 , SiF 6 , B (C 6 H 5 ) 4 , and B (oxalate). 2 , Cl, Br, and I.
 窒素、酸素、硫黄または炭素を含むアニオンの化学構造について、以下、具体的に説明する。 The chemical structure of an anion containing nitrogen, oxygen, sulfur or carbon will be specifically described below.
 塩のアニオンの化学構造は、下記一般式(1)、一般式(2)または一般式(3)で表される化学構造が好ましい。 The chemical structure of the anion of the salt is preferably a chemical structure represented by the following general formula (1), general formula (2), or general formula (3).
  (R)(R)N・・・・・・一般式(1)
(Rは、水素、ハロゲン、置換基で置換されていても良いアルキル基、置換基で置換されていても良いシクロアルキル基、置換基で置換されていても良い不飽和アルキル基、置換基で置換されていても良い不飽和シクロアルキル基、置換基で置換されていても良い芳香族基、置換基で置換されていても良い複素環基、置換基で置換されていても良いアルコキシ基、置換基で置換されていても良い不飽和アルコキシ基、置換基で置換されていても良いチオアルコキシ基、置換基で置換されていても良い不飽和チオアルコキシ基、CN、SCN、OCNから選択される。
 Rは、水素、ハロゲン、置換基で置換されていても良いアルキル基、置換基で置換されていても良いシクロアルキル基、置換基で置換されていても良い不飽和アルキル基、置換基で置換されていても良い不飽和シクロアルキル基、置換基で置換されていても良い芳香族基、置換基で置換されていても良い複素環基、置換基で置換されていても良いアルコキシ基、置換基で置換されていても良い不飽和アルコキシ基、置換基で置換されていても良いチオアルコキシ基、置換基で置換されていても良い不飽和チオアルコキシ基、CN、SCN、OCNからから選択される。
 また、RとRは、互いに結合して環を形成しても良い。
 Xは、SO、C=O、C=S、RP=O、RP=S、S=O、Si=Oから選択される。
 Xは、SO、C=O、C=S、RP=O、RP=S、S=O、Si=Oから選択される。
 R、R、R、Rは、それぞれ独立に、水素、ハロゲン、置換基で置換されていても良いアルキル基、置換基で置換されていても良いシクロアルキル基、置換基で置換されていても良い不飽和アルキル基、置換基で置換されていても良い不飽和シクロアルキル基、置換基で置換されていても良い芳香族基、置換基で置換されていても良い複素環基、置換基で置換されていても良いアルコキシ基、置換基で置換されていても良い不飽和アルコキシ基、置換基で置換されていても良いチオアルコキシ基、置換基で置換されていても良い不飽和チオアルコキシ基、OH、SH、CN、SCN、OCNから選択される。
 また、R、R、R、Rは、RまたはRと結合して環を形成しても良い。)
(R 1 X 1 ) (R 2 X 2 ) N... General formula (1)
(R 1 is hydrogen, halogen, an alkyl group which may be substituted with a substituent, a cycloalkyl group which may be substituted with a substituent, an unsaturated alkyl group which may be substituted with a substituent, or a substituent. An unsaturated cycloalkyl group which may be substituted with, an aromatic group which may be substituted with a substituent, a heterocyclic group which may be substituted with a substituent, or an alkoxy group which may be substituted with a substituent , An unsaturated alkoxy group that may be substituted with a substituent, a thioalkoxy group that may be substituted with a substituent, an unsaturated thioalkoxy group that may be substituted with a substituent, CN, SCN, or OCN Is done.
R 2 represents hydrogen, halogen, an alkyl group which may be substituted with a substituent, a cycloalkyl group which may be substituted with a substituent, an unsaturated alkyl group which may be substituted with a substituent, or a substituent. An unsaturated cycloalkyl group which may be substituted, an aromatic group which may be substituted with a substituent, a heterocyclic group which may be substituted with a substituent, an alkoxy group which may be substituted with a substituent, Select from an unsaturated alkoxy group optionally substituted with a substituent, a thioalkoxy group optionally substituted with a substituent, an unsaturated thioalkoxy group optionally substituted with a substituent, CN, SCN, and OCN Is done.
R 1 and R 2 may be bonded to each other to form a ring.
X 1 is selected from SO 2 , C = O, C = S, R a P = O, R b P = S, S = O, Si = O.
X 2 is, SO 2, C = O, C = S, R c P = O, R d P = S, S = O, is selected from Si = O.
R a , R b , R c , and R d are each independently hydrogen, halogen, an alkyl group that may be substituted with a substituent, a cycloalkyl group that may be substituted with a substituent, or a substituent. An unsaturated alkyl group which may be substituted, an unsaturated cycloalkyl group which may be substituted with a substituent, an aromatic group which may be substituted with a substituent, or a heterocyclic group which may be substituted with a substituent , An alkoxy group that may be substituted with a substituent, an unsaturated alkoxy group that may be substituted with a substituent, a thioalkoxy group that may be substituted with a substituent, and a non-optionally substituted substituent. Selected from saturated thioalkoxy groups, OH, SH, CN, SCN, OCN.
R a , R b , R c , and R d may combine with R 1 or R 2 to form a ring. )
  RY・・・・・・一般式(2)
(Rは、水素、ハロゲン、置換基で置換されていても良いアルキル基、置換基で置換されていても良いシクロアルキル基、置換基で置換されていても良い不飽和アルキル基、置換基で置換されていても良い不飽和シクロアルキル基、置換基で置換されていても良い芳香族基、置換基で置換されていても良い複素環基、置換基で置換されていても良いアルコキシ基、置換基で置換されていても良い不飽和アルコキシ基、置換基で置換されていても良いチオアルコキシ基、置換基で置換されていても良い不飽和チオアルコキシ基、CN、SCN、OCNから選択される。
 Xは、SO、C=O、C=S、RP=O、RP=S、S=O、Si=Oから選択される。
 R、Rは、それぞれ独立に、水素、ハロゲン、置換基で置換されていても良いアルキル基、置換基で置換されていても良いシクロアルキル基、置換基で置換されていても良い不飽和アルキル基、置換基で置換されていても良い不飽和シクロアルキル基、置換基で置換されていても良い芳香族基、置換基で置換されていても良い複素環基、置換基で置換されていても良いアルコキシ基、置換基で置換されていても良い不飽和アルコキシ基、置換基で置換されていても良いチオアルコキシ基、置換基で置換されていても良い不飽和チオアルコキシ基、OH、SH、CN、SCN、OCNから選択される。
 また、R、Rは、Rと結合して環を形成しても良い。
 Yは、O、Sから選択される。)
R 3 X 3 Y: General formula (2)
(R 3 is hydrogen, halogen, an alkyl group which may be substituted with a substituent, a cycloalkyl group which may be substituted with a substituent, an unsaturated alkyl group which may be substituted with a substituent, or a substituent. An unsaturated cycloalkyl group which may be substituted with, an aromatic group which may be substituted with a substituent, a heterocyclic group which may be substituted with a substituent, or an alkoxy group which may be substituted with a substituent , An unsaturated alkoxy group that may be substituted with a substituent, a thioalkoxy group that may be substituted with a substituent, an unsaturated thioalkoxy group that may be substituted with a substituent, CN, SCN, or OCN Is done.
X 3 is selected from SO 2 , C = O, C = S, R e P = O, R f P = S, S = O, and Si = O.
R e and R f are each independently hydrogen, halogen, an alkyl group that may be substituted with a substituent, a cycloalkyl group that may be substituted with a substituent, or a group that may be substituted with a substituent. A saturated alkyl group, an unsaturated cycloalkyl group that may be substituted with a substituent, an aromatic group that may be substituted with a substituent, a heterocyclic group that may be substituted with a substituent, and a substituent An alkoxy group which may be substituted, an unsaturated alkoxy group which may be substituted with a substituent, a thioalkoxy group which may be substituted with a substituent, an unsaturated thioalkoxy group which may be substituted with a substituent, OH , SH, CN, SCN, and OCN.
R e and R f may combine with R 3 to form a ring.
Y is selected from O and S. )
  (R)(R)(R)C・・・・・・一般式(3)
(Rは、水素、ハロゲン、置換基で置換されていても良いアルキル基、置換基で置換されていても良いシクロアルキル基、置換基で置換されていても良い不飽和アルキル基、置換基で置換されていても良い不飽和シクロアルキル基、置換基で置換されていても良い芳香族基、置換基で置換されていても良い複素環基、置換基で置換されていても良いアルコキシ基、置換基で置換されていても良い不飽和アルコキシ基、置換基で置換されていても良いチオアルコキシ基、置換基で置換されていても良い不飽和チオアルコキシ基、CN、SCN、OCNから選択される。
 Rは、水素、ハロゲン、置換基で置換されていても良いアルキル基、置換基で置換されていても良いシクロアルキル基、置換基で置換されていても良い不飽和アルキル基、置換基で置換されていても良い不飽和シクロアルキル基、置換基で置換されていても良い芳香族基、置換基で置換されていても良い複素環基、置換基で置換されていても良いアルコキシ基、置換基で置換されていても良い不飽和アルコキシ基、置換基で置換されていても良いチオアルコキシ基、置換基で置換されていても良い不飽和チオアルコキシ基、CN、SCN、OCNから選択される。
 Rは、水素、ハロゲン、置換基で置換されていても良いアルキル基、置換基で置換されていても良いシクロアルキル基、置換基で置換されていても良い不飽和アルキル基、置換基で置換されていても良い不飽和シクロアルキル基、置換基で置換されていても良い芳香族基、置換基で置換されていても良い複素環基、置換基で置換されていても良いアルコキシ基、置換基で置換されていても良い不飽和アルコキシ基、置換基で置換されていても良いチオアルコキシ基、置換基で置換されていても良い不飽和チオアルコキシ基、CN、SCN、OCNから選択される。
 また、R、R、Rのうち、いずれか二つまたは三つが結合して環を形成しても良い。
 Xは、SO、C=O、C=S、RP=O、RP=S、S=O、Si=Oから選択される。
 Xは、SO、C=O、C=S、RP=O、RP=S、S=O、Si=Oから選択される。
 Xは、SO、C=O、C=S、RP=O、RP=S、S=O、Si=Oから選択される。
 R、R、R、R、R、Rは、それぞれ独立に、水素、ハロゲン、置換基で置換されていても良いアルキル基、置換基で置換されていても良いシクロアルキル基、置換基で置換されていても良い不飽和アルキル基、置換基で置換されていても良い不飽和シクロアルキル基、置換基で置換されていても良い芳香族基、置換基で置換されていても良い複素環基、置換基で置換されていても良いアルコキシ基、置換基で置換されていても良い不飽和アルコキシ基、置換基で置換されていても良いチオアルコキシ基、置換基で置換されていても良い不飽和チオアルコキシ基、OH、SH、CN、SCN、OCNから選択される。
 また、R、R、R、R、R、Rは、R、RまたはRと結合して環を形成しても良い。)
(R 4 X 4 ) (R 5 X 5 ) (R 6 X 6 ) C ... General formula (3)
(R 4 is hydrogen, halogen, an alkyl group which may be substituted with a substituent, a cycloalkyl group which may be substituted with a substituent, an unsaturated alkyl group which may be substituted with a substituent, or a substituent. An unsaturated cycloalkyl group which may be substituted with, an aromatic group which may be substituted with a substituent, a heterocyclic group which may be substituted with a substituent, or an alkoxy group which may be substituted with a substituent , An unsaturated alkoxy group that may be substituted with a substituent, a thioalkoxy group that may be substituted with a substituent, an unsaturated thioalkoxy group that may be substituted with a substituent, CN, SCN, or OCN Is done.
R 5 represents hydrogen, halogen, an alkyl group which may be substituted with a substituent, a cycloalkyl group which may be substituted with a substituent, an unsaturated alkyl group which may be substituted with a substituent, or a substituent. An unsaturated cycloalkyl group which may be substituted, an aromatic group which may be substituted with a substituent, a heterocyclic group which may be substituted with a substituent, an alkoxy group which may be substituted with a substituent, Selected from an unsaturated alkoxy group which may be substituted with a substituent, a thioalkoxy group which may be substituted with a substituent, an unsaturated thioalkoxy group which may be substituted with a substituent, CN, SCN, OCN The
R 6 is hydrogen, halogen, an alkyl group which may be substituted with a substituent, a cycloalkyl group which may be substituted with a substituent, an unsaturated alkyl group which may be substituted with a substituent, or a substituent. An unsaturated cycloalkyl group which may be substituted, an aromatic group which may be substituted with a substituent, a heterocyclic group which may be substituted with a substituent, an alkoxy group which may be substituted with a substituent, Selected from an unsaturated alkoxy group which may be substituted with a substituent, a thioalkoxy group which may be substituted with a substituent, an unsaturated thioalkoxy group which may be substituted with a substituent, CN, SCN, OCN The
Further, any two or three of R 4 , R 5 and R 6 may be bonded to form a ring.
X 4 is, SO 2, C = O, C = S, R g P = O, R h P = S, S = O, is selected from Si = O.
X 5 is selected from SO 2 , C = O, C = S, R i P = O, R j P = S, S = O, Si = O.
X 6 is selected from SO 2 , C = O, C = S, R k P = O, R 1 P = S, S = O, Si = O.
R g , R h , R i , R j , R k , and R l are each independently hydrogen, halogen, an alkyl group that may be substituted with a substituent, or a cycloalkyl that may be substituted with a substituent. Group, an unsaturated alkyl group that may be substituted with a substituent, an unsaturated cycloalkyl group that may be substituted with a substituent, an aromatic group that may be substituted with a substituent, or a substituent that is substituted with a substituent A heterocyclic group which may be substituted, an alkoxy group which may be substituted with a substituent, an unsaturated alkoxy group which may be substituted with a substituent, a thioalkoxy group which may be substituted with a substituent, and a substituent It is selected from an unsaturated thioalkoxy group which may be substituted, OH, SH, CN, SCN, OCN.
R g , R h , R i , R j , R k , and R l may combine with R 4 , R 5, or R 6 to form a ring. )
 上記一般式(1)~(3)で表される化学構造における、「置換基で置換されていても良い」との文言について説明する。例えば「置換基で置換されていても良いアルキル基」であれば、アルキル基の水素の一つ若しくは複数が置換基で置換されているアルキル基、または、特段の置換基を有さないアルキル基を意味する。 The term “may be substituted with a substituent” in the chemical structure represented by the general formulas (1) to (3) will be described. For example, in the case of “an alkyl group which may be substituted with a substituent”, an alkyl group in which one or more of hydrogens of the alkyl group are substituted with a substituent, or an alkyl group having no particular substituent Means.
 「置換基で置換されていても良い」との文言における置換基としては、アルキル基、アルケニル基、アルキニル基、シクロアルキル基、不飽和シクロアルキル基、芳香族基、複素環基、ハロゲン、OH、SH、CN、SCN、OCN、ニトロ基、アルコキシ基、不飽和アルコキシ基、アミノ基、アルキルアミノ基、ジアルキルアミノ基、アリールオキシ基、アシル基、アルコキシカルボニル基、アシルオキシ基、アリールオキシカルボニル基、アシルオキシ基、アシルアミノ基、アルコキシカルボニルアミノ基、アリールオキシカルボニルアミノ基、スルホニルアミノ基、スルファモイル基、カルバモイル基、アルキルチオ基、アリールチオ基、スルホニル基、スルフィニル基、ウレイド基、リン酸アミド基、スルホ基、カルボキシル基、ヒドロキサム酸基、スルフィノ基、ヒドラジノ基、イミノ基、シリル基等が挙げられる。これらの置換基はさらに置換されてもよい。また置換基が2つ以上ある場合、置換基は同一でも異なっていてもよい。 Examples of the substituent in the phrase “may be substituted with a substituent” include an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, an unsaturated cycloalkyl group, an aromatic group, a heterocyclic group, a halogen, and OH. SH, CN, SCN, OCN, nitro group, alkoxy group, unsaturated alkoxy group, amino group, alkylamino group, dialkylamino group, aryloxy group, acyl group, alkoxycarbonyl group, acyloxy group, aryloxycarbonyl group, Acyloxy group, acylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, sulfonylamino group, sulfamoyl group, carbamoyl group, alkylthio group, arylthio group, sulfonyl group, sulfinyl group, ureido group, phosphoric acid amide group, sulfo group, Carboxyl group, Dorokisamu acid group, a sulfino group, a hydrazino group, an imino group, and a silyl group. These substituents may be further substituted. When there are two or more substituents, the substituents may be the same or different.
 塩のアニオンの化学構造は、下記一般式(4)、一般式(5)または一般式(6)で表される化学構造がより好ましい。 The chemical structure of the salt anion is more preferably a chemical structure represented by the following general formula (4), general formula (5), or general formula (6).
  (R)(R)N・・・・・・一般式(4)
(R、Rは、それぞれ独立に、CClBr(CN)(SCN)(OCN)である。
 n、a、b、c、d、e、f、g、hはそれぞれ独立に0以上の整数であり、2n+1=a+b+c+d+e+f+g+hを満たす。
 また、RとRは、互いに結合して環を形成しても良く、その場合は、2n=a+b+c+d+e+f+g+hを満たす。
 Xは、SO、C=O、C=S、RP=O、RP=S、S=O、Si=Oから選択される。
 Xは、SO、C=O、C=S、RP=O、RP=S、S=O、Si=Oから選択される。
 R、R、R、Rは、それぞれ独立に、水素、ハロゲン、置換基で置換されていても良いアルキル基、置換基で置換されていても良いシクロアルキル基、置換基で置換されていても良い不飽和アルキル基、置換基で置換されていても良い不飽和シクロアルキル基、置換基で置換されていても良い芳香族基、置換基で置換されていても良い複素環基、置換基で置換されていても良いアルコキシ基、置換基で置換されていても良い不飽和アルコキシ基、置換基で置換されていても良いチオアルコキシ基、置換基で置換されていても良い不飽和チオアルコキシ基、OH、SH、CN、SCN、OCNから選択される。
 また、R、R、R、Rは、RまたはRと結合して環を形成しても良い。)
(R 7 X 7 ) (R 8 X 8 ) N ... General formula (4)
(R 7 and R 8 are each independently C n H a F b Cl c Br d I e (CN) f (SCN) g (OCN) h .
n, a, b, c, d, e, f, g, and h are each independently an integer of 0 or more, and satisfy 2n + 1 = a + b + c + d + e + f + g + h.
R 7 and R 8 may combine with each other to form a ring, in which case 2n = a + b + c + d + e + f + g + h is satisfied.
X 7 is, SO 2, C = O, C = S, R m P = O, R n P = S, S = O, is selected from Si = O.
X 8 is selected from SO 2 , C = O, C = S, R o P = O, R p P = S, S = O, Si = O.
R m , R n , R o , and R p are each independently substituted with hydrogen, halogen, an alkyl group that may be substituted with a substituent, a cycloalkyl group that may be substituted with a substituent, or a substituent. An unsaturated alkyl group which may be substituted, an unsaturated cycloalkyl group which may be substituted with a substituent, an aromatic group which may be substituted with a substituent, or a heterocyclic group which may be substituted with a substituent , An alkoxy group that may be substituted with a substituent, an unsaturated alkoxy group that may be substituted with a substituent, a thioalkoxy group that may be substituted with a substituent, and a non-optionally substituted substituent. Selected from saturated thioalkoxy groups, OH, SH, CN, SCN, OCN.
R m , R n , R o , and R p may combine with R 7 or R 8 to form a ring. )
  RY・・・・・・一般式(5)
(Rは、CClBr(CN)(SCN)(OCN)である。
 n、a、b、c、d、e、f、g、hはそれぞれ独立に0以上の整数であり、2n+1=a+b+c+d+e+f+g+hを満たす。
 Xは、SO、C=O、C=S、RP=O、RP=S、S=O、Si=Oから選択される。
 R、Rは、それぞれ独立に、水素、ハロゲン、置換基で置換されていても良いアルキル基、置換基で置換されていても良いシクロアルキル基、置換基で置換されていても良い不飽和アルキル基、置換基で置換されていても良い不飽和シクロアルキル基、置換基で置換されていても良い芳香族基、置換基で置換されていても良い複素環基、置換基で置換されていても良いアルコキシ基、置換基で置換されていても良い不飽和アルコキシ基、置換基で置換されていても良いチオアルコキシ基、置換基で置換されていても良い不飽和チオアルコキシ基、OH、SH、CN、SCN、OCNから選択される。
 また、R、Rは、Rと結合して環を形成しても良い。
 Yは、O、Sから選択される。)
R 9 X 9 Y: General formula (5)
(R 9 is a C n H a F b Cl c Br d I e (CN) f (SCN) g (OCN) h.
n, a, b, c, d, e, f, g, and h are each independently an integer of 0 or more, and satisfy 2n + 1 = a + b + c + d + e + f + g + h.
X 9 is, SO 2, C = O, C = S, R q P = O, R r P = S, S = O, is selected from Si = O.
R q and R r are each independently hydrogen, halogen, an alkyl group that may be substituted with a substituent, a cycloalkyl group that may be substituted with a substituent, or a group that may be substituted with a substituent. A saturated alkyl group, an unsaturated cycloalkyl group that may be substituted with a substituent, an aromatic group that may be substituted with a substituent, a heterocyclic group that may be substituted with a substituent, and a substituent An alkoxy group which may be substituted, an unsaturated alkoxy group which may be substituted with a substituent, a thioalkoxy group which may be substituted with a substituent, an unsaturated thioalkoxy group which may be substituted with a substituent, OH , SH, CN, SCN, and OCN.
R q and R r may combine with R 9 to form a ring.
Y is selected from O and S. )
  (R1010)(R1111)(R1212)C・・・・・・一般式(6)
(R10、R11、R12は、それぞれ独立に、CClBr(CN)(SCN)(OCN)である。
 n、a、b、c、d、e、f、g、hはそれぞれ独立に0以上の整数であり、2n+1=a+b+c+d+e+f+g+hを満たす。
 R10、R11、R12のうちいずれか二つが結合して環を形成しても良く、その場合、環を形成する基は2n=a+b+c+d+e+f+g+hを満たす。また、R10、R11、R12の三つが結合して環を形成しても良く、その場合、三つのうち二つの基が2n=a+b+c+d+e+f+g+hを満たし、一つの基が2n-1=a+b+c+d+e+f+g+hを満たす。
 X10は、SO、C=O、C=S、RP=O、RP=S、S=O、Si=Oから選択される。
 X11は、SO、C=O、C=S、RP=O、RP=S、S=O、Si=Oから選択される。
 X12は、SO、C=O、C=S、RP=O、RP=S、S=O、Si=Oから選択される。
 R、R、R、R、R、Rは、それぞれ独立に、水素、ハロゲン、置換基で置換されていても良いアルキル基、置換基で置換されていても良いシクロアルキル基、置換基で置換されていても良い不飽和アルキル基、置換基で置換されていても良い不飽和シクロアルキル基、置換基で置換されていても良い芳香族基、置換基で置換されていても良い複素環基、置換基で置換されていても良いアルコキシ基、置換基で置換されていても良い不飽和アルコキシ基、置換基で置換されていても良いチオアルコキシ基、置換基で置換されていても良い不飽和チオアルコキシ基、OH、SH、CN、SCN、OCNから選択される。
 また、R、R、R、R、R、Rは、R10、R11またはR12と結合して環を形成しても良い。)
(R 10 X 10 ) (R 11 X 11 ) (R 12 X 12 ) C ... General formula (6)
(R 10 , R 11 , and R 12 are each independently C n H a F b Cl c Br d I e (CN) f (SCN) g (OCN) h .
n, a, b, c, d, e, f, g, and h are each independently an integer of 0 or more, and satisfy 2n + 1 = a + b + c + d + e + f + g + h.
Any two of R 10 , R 11 , and R 12 may combine to form a ring, in which case the group forming the ring satisfies 2n = a + b + c + d + e + f + g + h. Three of R 10 , R 11 and R 12 may combine to form a ring, in which case two of the three satisfy 2n = a + b + c + d + e + f + g + h, and one group satisfies 2n−1 = a + b + c + d + e + f + g + h. Fulfill.
X 10 is, SO 2, C = O, C = S, R s P = O, R t P = S, S = O, is selected from Si = O.
X 11 is, SO 2, C = O, C = S, R u P = O, R v P = S, S = O, is selected from Si = O.
X 12 is, SO 2, C = O, C = S, R w P = O, R x P = S, S = O, is selected from Si = O.
R s , R t , R u , R v , R w , and R x are each independently hydrogen, halogen, an alkyl group that may be substituted with a substituent, or a cycloalkyl that may be substituted with a substituent. Group, an unsaturated alkyl group that may be substituted with a substituent, an unsaturated cycloalkyl group that may be substituted with a substituent, an aromatic group that may be substituted with a substituent, or a substituent that is substituted with a substituent A heterocyclic group which may be substituted, an alkoxy group which may be substituted with a substituent, an unsaturated alkoxy group which may be substituted with a substituent, a thioalkoxy group which may be substituted with a substituent, and a substituent It is selected from an unsaturated thioalkoxy group which may be substituted, OH, SH, CN, SCN, OCN.
R s , R t , R u , R v , R w , and R x may combine with R 10 , R 11, or R 12 to form a ring. )
 上記一般式(4)~(6)で表される化学構造における、「置換基で置換されていても良い」との文言の意味は、上記一般式(1)~(3)で説明したのと同義である。 The meaning of the phrase “may be substituted with a substituent” in the chemical structures represented by the general formulas (4) to (6) has been explained in the general formulas (1) to (3). It is synonymous with.
 上記一般式(4)~(6)で表される化学構造において、nは0~6の整数が好ましく、0~4の整数がより好ましく、0~2の整数が特に好ましい。なお、上記一般式(4)~(6)で表される化学構造の、RとRが結合、または、R10、R11、R12が結合して環を形成している場合には、nは1~8の整数が好ましく、1~7の整数がより好ましく、1~3の整数が特に好ましい。 In the chemical structures represented by the general formulas (4) to (6), n is preferably an integer of 0 to 6, more preferably an integer of 0 to 4, and particularly preferably an integer of 0 to 2. In the chemical structures represented by the general formulas (4) to (6), when R 7 and R 8 are bonded, or R 10 , R 11 , and R 12 are bonded to form a ring. In the formula, n is preferably an integer of 1 to 8, more preferably an integer of 1 to 7, and particularly preferably an integer of 1 to 3.
 塩のアニオンの化学構造は、下記一般式(7)、一般式(8)または一般式(9)で表されるものがさらに好ましい。 The chemical structure of the salt anion is more preferably represented by the following general formula (7), general formula (8) or general formula (9).
  (R13SO)(R14SO)N・・・・・・一般式(7)
(R13、R14は、それぞれ独立に、CClBrである。
 n、a、b、c、d、eはそれぞれ独立に0以上の整数であり、2n+1=a+b+c+d+eを満たす。
 また、R13とR14は、互いに結合して環を形成しても良く、その場合は、2n=a+b+c+d+eを満たす。)
(R 13 SO 2 ) (R 14 SO 2 ) N... General formula (7)
(R 13 and R 14 are each independently C n H a F b Cl c Br d I e .
n, a, b, c, d, and e are each independently an integer of 0 or more, and satisfy 2n + 1 = a + b + c + d + e.
R 13 and R 14 may combine with each other to form a ring, in which case 2n = a + b + c + d + e is satisfied. )
  R15SO・・・・・・一般式(8)
(R15は、CClBrである。
 n、a、b、c、d、eはそれぞれ独立に0以上の整数であり、2n+1=a+b+c+d+eを満たす。)
R 15 SO 3 ... General formula (8)
(R 15 is a C n H a F b Cl c Br d I e.
n, a, b, c, d, and e are each independently an integer of 0 or more, and satisfy 2n + 1 = a + b + c + d + e. )
  (R16SO)(R17SO)(R18SO)C・・・・・一般式(9)
(R16、R17、R18は、それぞれ独立に、CClBrである。
 n、a、b、c、d、eはそれぞれ独立に0以上の整数であり、2n+1=a+b+c+d+eを満たす。
 R16、R17、R18のうちいずれか二つが結合して環を形成しても良く、その場合、環を形成する基は2n=a+b+c+d+eを満たす。また、R16、R17、R18の三つが結合して環を形成しても良く、その場合、三つのうち二つの基が2n=a+b+c+d+eを満たし、一つの基が2n-1=a+b+c+d+eを満たす。)
(R 16 SO 2 ) (R 17 SO 2 ) (R 18 SO 2 ) C General formula (9)
(R 16 , R 17 , and R 18 are each independently C n H a F b Cl c Br d I e .
n, a, b, c, d, and e are each independently an integer of 0 or more, and satisfy 2n + 1 = a + b + c + d + e.
Any two of R 16 , R 17 and R 18 may combine to form a ring, in which case the group forming the ring satisfies 2n = a + b + c + d + e. Three of R 16 , R 17 and R 18 may combine to form a ring, in which case two of the three satisfy 2n = a + b + c + d + e, and one group satisfies 2n−1 = a + b + c + d + e. Fulfill. )
 上記一般式(7)~(9)で表される化学構造において、nは0~6の整数が好ましく、0~4の整数がより好ましく、0~2の整数が特に好ましい。なお、上記一般式(7)~(9)で表される化学構造の、R13とR14が結合、または、R16、R17、R18が結合して環を形成している場合には、nは1~8の整数が好ましく、1~7の整数がより好ましく、1~3の整数が特に好ましい。 In the chemical structures represented by the general formulas (7) to (9), n is preferably an integer of 0 to 6, more preferably an integer of 0 to 4, and particularly preferably an integer of 0 to 2. In the chemical structures represented by the above general formulas (7) to (9), when R 13 and R 14 are bonded, or R 16 , R 17 and R 18 are bonded to form a ring. In the formula, n is preferably an integer of 1 to 8, more preferably an integer of 1 to 7, and particularly preferably an integer of 1 to 3.
 また、上記一般式(7)~(9)で表される化学構造において、a、c、d、eが0のものが好ましい。 In the chemical structures represented by the general formulas (7) to (9), those in which a, c, d, and e are 0 are preferable.
 金属塩は、(CFSONLi(以下、「LiTFSA」ということがある。)、(FSONLi(以下、「LiFSA」ということがある。)、(CSONLi、FSO(CFSO)NLi、(SOCFCFSO)NLi、(SOCFCFCFSO)NLi、FSO(CHSO)NLi、FSO(CSO)NLi、またはFSO(CSO)NLiが特に好ましい。なお、これらの金属塩はイミド塩である。したがって、金属塩としてイミド塩を用いるのが特に好ましいと言うこともできる。 The metal salt is (CF 3 SO 2 ) 2 NLi (hereinafter sometimes referred to as “LiTFSA”), (FSO 2 ) 2 NLi (hereinafter sometimes referred to as “LiFSA”), (C 2 F 5 SO 2 ) 2 NLi, FSO 2 (CF 3 SO 2 ) NLi, (SO 2 CF 2 CF 2 SO 2 ) NLi, (SO 2 CF 2 CF 2 CF 2 SO 2 ) NLi, FSO 2 (CH 3 SO 2 ) NLi FSO 2 (C 2 F 5 SO 2 ) NLi or FSO 2 (C 2 H 5 SO 2 ) NLi is particularly preferred. These metal salts are imide salts. Therefore, it can be said that it is particularly preferable to use an imide salt as the metal salt.
 金属塩は、以上で説明したカチオンとアニオンをそれぞれ適切な数で組み合わせたものを採用すれば良い。金属塩は上記の一種類を採用しても良いし、複数種を併用しても良い。 The metal salt may be a combination of an appropriate number of cations and anions described above. One kind of metal salt may be adopted, or a plurality of kinds may be used in combination.
 一方、電解液(1)における金属塩は、アニオンの化学構造に硫黄元素および酸素元素を含むものであり、金属塩のカチオンについては上記した本発明の電解液と同様である。 On the other hand, the metal salt in the electrolytic solution (1) contains a sulfur element and an oxygen element in the chemical structure of the anion, and the cation of the metal salt is the same as that of the above-described electrolytic solution of the present invention.
 電解液(1)における塩のアニオンの化学構造は硫黄元素および酸素元素を含む。このアニオンの化学構造について、以下、具体的に説明する。なお、以下には本発明の電解液と本発明の電解液(1)との違いについてのみ説明する。したがって、特に説明のない事項については、電解液(1)は本発明の電解液と同様である、 The chemical structure of the anion of the salt in the electrolytic solution (1) contains sulfur element and oxygen element. The chemical structure of this anion will be specifically described below. Hereinafter, only the difference between the electrolytic solution of the present invention and the electrolytic solution (1) of the present invention will be described. Therefore, unless otherwise specified, the electrolytic solution (1) is the same as the electrolytic solution of the present invention.
 塩のアニオンの化学構造は、上記した一般式(1)、一般式(2)または一般式(3)で表される化学構造が好ましいが、以下のように、X~Xについては上記のX~Xよりもさらに限定されている。 The chemical structure of the anion of the salt is preferably a chemical structure represented by the above general formula (1), general formula (2), or general formula (3), but X 1 to X 5 are as described above. The X 1 to X 5 are more limited.
 電解液(1)においては、一般式(1)のXはSO、S=Oから選択され、Xは、SO、S=Oから選択される。 In the electrolytic solution (1), X 1 in the general formula (1) is selected from SO 2, S = O, X 2 is selected from SO 2, S = O.
 また電解液(1)においては、一般式(2)のXは、SO、S=Oから選択される。 In the electrolytic solution (1), X 3 in the general formula (2) is selected from SO 2 and S═O.
 また電解液(1)においては、一般式(3)のXは、SO、S=Oから選択され、Xは、SO、S=Oから選択され、Xは、SO、S=Oから選択される。 In the electrolytic solution (1), X 4 in the general formula (3) is selected from SO 2, S = O, X 5 is selected from SO 2, S = O, X 6 is SO 2, S = O is selected.
 塩のアニオンの化学構造は、上記した一般式(4)、一般式(5)または一般式(6)で表される化学構造がより好ましいが、以下のように、X~X12については上記のX~X12よりもさらに限定されている。 The chemical structure of the anion of the salt is more preferably a chemical structure represented by the above general formula (4), general formula (5), or general formula (6), but X 7 to X 12 are as follows. More limited than the above X 7 to X 12 .
 電解液(1)においては、一般式(4)のXは、SO、S=Oから選択され、Xは、SO、S=Oから選択される。 In the electrolytic solution (1), X 7 in the general formula (4) is selected from SO 2, S = O, X 8 is selected from SO 2, S = O.
 また、電解液(1)においては、一般式(5)のXは、SO、S=Oから選択される。 In the electrolytic solution (1), X 9 in the general formula (5) is selected from SO 2 and S═O.
 また、電解液(1)においては、一般式(6)のX10は、SO、S=Oから選択され、X11は、SO、S=Oから選択され、X12は、SO、S=Oから選択される。 In the electrolytic solution (1), X 10 in the general formula (6) is selected from SO 2, S = O, X 11 is selected from SO 2, S = O, X 12 is SO 2 , S = O.
 〔有機溶媒〕
 ヘテロ元素を有する有機溶媒としては、ヘテロ元素が窒素、酸素、硫黄、ハロゲンから選択される少なくとも1つである有機溶媒が好ましく、ヘテロ元素が窒素または酸素から選択される少なくとも1つである有機溶媒がより好ましい。また、ヘテロ元素を有する有機溶媒としては、NH基、NH基、OH基、SH基などのプロトン供与基を有さない、非プロトン性溶媒が好ましい。
[Organic solvent]
As the organic solvent having a hetero element, an organic solvent in which the hetero element is at least one selected from nitrogen, oxygen, sulfur and halogen is preferable, and an organic solvent in which the hetero element is at least one selected from nitrogen or oxygen Is more preferable. As the organic solvent having a hetero element, an aprotic solvent having no proton donating group such as NH group, NH 2 group, OH group, and SH group is preferable.
 ヘテロ元素を有する有機溶媒(以下、単に「有機溶媒」ということがある。)を具体的に例示すると、アセトニトリル、プロピオニトリル、アクリロニトリル、マロノニトリル等のニトリル類、1,2-ジメトキシエタン、1,2-ジエトキシエタン、テトラヒドロフラン、1,2-ジオキサン、1,3-ジオキサン、1,4-ジオキサン、2,2-ジメチル-1,3-ジオキソラン、2-メチルテトラヒドロピラン、2-メチルテトラヒドロフラン、クラウンエーテル等のエーテル類、エチレンカーボネート、プロピレンカーボネート、ジメチルカーボネート、ジエチルカーボネート、エチルメチルカーボネート等のカーボネート類、ホルムアミド、N,N-ジメチルホルムアミド、N,N-ジメチルアセトアミド、N-メチルピロリドン等のアミド類、イソプロピルイソシアネート、n-プロピルイソシアネート、クロロメチルイソシアネート等のイソシアネート類、酢酸メチル、酢酸エチル、酢酸プロピル、プロピオン酸メチル、蟻酸メチル、蟻酸エチル、酢酸ビニル、メチルアクリレート、メチルメタクリレート等のエステル類、グリシジルメチルエーテル、エポキシブタン、2-エチルオキシラン等のエポキシ類、オキサゾール、2-エチルオキサゾール、オキサゾリン、2-メチル-2-オキサゾリン等のオキサゾール類、アセトン、メチルエチルケトン、メチルイソブチルケトン等のケトン類、無水酢酸、無水プロピオン酸等の酸無水物、ジメチルスルホン、スルホラン等のスルホン類、ジメチルスルホキシド等のスルホキシド類、1-ニトロプロパン、2-ニトロプロパン等のニトロ類、フラン、フルフラール等のフラン類、γ―ブチロラクトン、γ―バレロラクトン、δ―バレロラクトン等の環状エステル類、チオフェン、ピリジン等の芳香族複素環類、テトラヒドロ-4-ピロン、1-メチルピロリジン、N-メチルモルフォリン等の複素環類、リン酸トリメチル、リン酸トリエチル等のリン酸エステル類を挙げることができる。 Specific examples of the organic solvent having a hetero element (hereinafter sometimes simply referred to as “organic solvent”) include nitriles such as acetonitrile, propionitrile, acrylonitrile, malononitrile, 1,2-dimethoxyethane, 1, 2-diethoxyethane, tetrahydrofuran, 1,2-dioxane, 1,3-dioxane, 1,4-dioxane, 2,2-dimethyl-1,3-dioxolane, 2-methyltetrahydropyran, 2-methyltetrahydrofuran, crown Ethers such as ether, carbonates such as ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, and ethylmethyl carbonate, formamide, N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolide Amides such as isopropyl isocyanate, n-propyl isocyanate, chloromethyl isocyanate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, methyl formate, ethyl formate, vinyl acetate, methyl acrylate, methyl methacrylate, etc. Esters, glycidyl methyl ether, epoxy butane, epoxy such as 2-ethyloxirane, oxazole, 2-ethyloxazole, oxazoline, oxazole such as 2-methyl-2-oxazoline, ketone such as acetone, methyl ethyl ketone, methyl isobutyl ketone Acid anhydrides such as acetic anhydride and propionic anhydride, sulfones such as dimethyl sulfone and sulfolane, sulfoxides such as dimethyl sulfoxide, 1-nitropropane and 2-nitrate Nitros such as propane, furans such as furan and furfural, cyclic esters such as γ-butyrolactone, γ-valerolactone and δ-valerolactone, aromatic heterocycles such as thiophene and pyridine, tetrahydro-4-pyrone, Examples thereof include heterocyclic rings such as 1-methylpyrrolidine and N-methylmorpholine, and phosphate esters such as trimethyl phosphate and triethyl phosphate.
 さらにヘテロ元素を有する有機溶媒として、下記一般式(10)で表される鎖状カーボネートを挙げることもできる。 Further, examples of the organic solvent having a hetero element may include a chain carbonate represented by the following general formula (10).
  R19OCOOR20・・・・・・一般式(10)
(R19、R20は、それぞれ独立に、鎖状アルキルであるCClBr、または、環状アルキルを化学構造に含むCClBrのいずれかから選択される。n、a、b、c、d、e、m、f、g、h、i、jはそれぞれ独立に0以上の整数であり、2n+1=a+b+c+d+e、2m=f+g+h+i+jを満たす。)
R 19 OCOOR 20 ··· General formula (10)
(R 19 and R 20 are each independently C n H a F b Cl c Br d I e which is a chain alkyl, or C m H f F g Cl h Br i I containing a cyclic alkyl in the chemical structure. .n selected from any of j, a, b, c, d, e, m, f, g, h, i, j are each independently an integer of 0 or more, 2n + 1 = a + b + c + d + e, 2m = f + g + h + i + j Meet)
 上記一般式(10)で表される鎖状カーボネートにおいて、nは1~6の整数が好ましく、1~4の整数がより好ましく、1~2の整数が特に好ましい。mは3~8の整数が好ましく、4~7の整数がより好ましく、5~6の整数が特に好ましい。また、上記一般式(10)で表される鎖状カーボネートのうち、ジメチルカーボネート(以下、「DMC」ということがある。)、ジエチルカーボネート(以下、「DEC」ということがある。)、エチルメチルカーボネート(以下、「EMC」ということがある。)が特に好ましい。 In the chain carbonate represented by the general formula (10), n is preferably an integer of 1 to 6, more preferably an integer of 1 to 4, and particularly preferably an integer of 1 to 2. m is preferably an integer of 3 to 8, more preferably an integer of 4 to 7, and particularly preferably an integer of 5 to 6. Among the chain carbonates represented by the general formula (10), dimethyl carbonate (hereinafter sometimes referred to as “DMC”), diethyl carbonate (hereinafter sometimes referred to as “DEC”), ethylmethyl Carbonate (hereinafter sometimes referred to as “EMC”) is particularly preferred.
 ヘテロ元素を有する有機溶媒としては、比誘電率が20以上またはドナー性のエーテル酸素を有する溶媒が好ましく、そのような有機溶媒として、アセトニトリル、プロピオニトリル、アクリロニトリル、マロノニトリル等のニトリル類、1,2-ジメトキシエタン、1,2-ジエトキシエタン、テトラヒドロフラン、1,2-ジオキサン、1,3-ジオキサン、1,4-ジオキサン、2,2-ジメチル-1,3-ジオキソラン、2-メチルテトラヒドロピラン、2-メチルテトラヒドロフラン、クラウンエーテル等のエーテル類、N,N-ジメチルホルムアミド、アセトン、ジメチルスルホキシド、スルホランを挙げることができ、特に、アセトニトリル(以下、「AN」ということがある。)、1,2-ジメトキシエタン(以下、「DME」ということがある。)が好ましい。
 これらの有機溶媒は単独で電解液に用いても良いし、複数を併用しても良い。
As the organic solvent having a hetero element, a solvent having a relative dielectric constant of 20 or more or a donor ether oxygen is preferable. Examples of such an organic solvent include nitriles such as acetonitrile, propionitrile, acrylonitrile, and malononitrile, 2-dimethoxyethane, 1,2-diethoxyethane, tetrahydrofuran, 1,2-dioxane, 1,3-dioxane, 1,4-dioxane, 2,2-dimethyl-1,3-dioxolane, 2-methyltetrahydropyran And ethers such as 2-methyltetrahydrofuran and crown ether, N, N-dimethylformamide, acetone, dimethyl sulfoxide, and sulfolane. In particular, acetonitrile (hereinafter sometimes referred to as “AN”), 1, 2-dimethoxyethane (hereinafter referred to as “DM There is the fact that ".) Is preferred.
These organic solvents may be used alone in the electrolytic solution, or a plurality of them may be used in combination.
 本発明の電解液は、その振動分光スペクトルにおいて、電解液に含まれる有機溶媒由来のピーク強度につき、有機溶媒本来のピークの強度をIoとし、有機溶媒本来のピークがシフトしたピーク(以下、「シフトピーク」ということがある。)の強度をIsとした場合、Is>Ioであることを特徴とする。すなわち、本発明の電解液を振動分光測定に供し得られる振動分光スペクトルチャートにおいて、上記2つのピーク強度の関係はIs>Ioとなる。 In the vibrational spectroscopic spectrum of the electrolyte solution of the present invention, the peak intensity derived from the organic solvent contained in the electrolyte solution is denoted by Io, and the peak of the organic solvent inherent peak is shifted (hereinafter, “ If the intensity of “shift peak” is sometimes referred to as “Is”, Is> Io. That is, in the vibrational spectral spectrum chart obtained by subjecting the electrolytic solution of the present invention to vibrational spectral measurement, the relationship between the two peak intensities is Is> Io.
 ここで、「有機溶媒本来のピーク」とは、有機溶媒のみを振動分光測定した場合のピーク位置(波数)に、観察されるピークを意味する。有機溶媒本来のピークの強度Ioの値と、シフトピークの強度Isの値は、振動分光スペクトルにおける各ピークのベースラインからの高さまたは面積である。 Here, “the original peak of the organic solvent” means a peak observed at the peak position (wave number) when vibration spectroscopy measurement is performed only on the organic solvent. The value of the intensity Io of the original peak of the organic solvent and the value of the intensity Is of the shift peak are the height or area from the baseline of each peak in the vibrational spectrum.
 本発明の電解液の振動分光スペクトルにおいて、有機溶媒本来のピークがシフトしたピークが複数存在する場合には、最もIsとIoの関係を判断しやすいピークに基づいて当該関係を判断すればよい。また、本発明の電解液にヘテロ元素を有する有機溶媒を複数種用いた場合には、最もIsとIoの関係を判断しやすい(最もIsとIoの差が顕著な)有機溶媒を選択し、そのピーク強度に基づいてIsとIoの関係を判断すればよい。また、ピークのシフト量が小さく、シフト前後のピークが重なってなだらかな山のように見える場合は、既知の手段を用いてピーク分離を行い、IsとIoの関係を判断してもよい。 In the vibrational spectroscopic spectrum of the electrolytic solution of the present invention, when there are a plurality of peaks in which the original peak of the organic solvent is shifted, the relationship may be determined based on the peak from which the relationship between Is and Io is most easily determined. In addition, when a plurality of organic solvents having heteroelements are used in the electrolytic solution of the present invention, an organic solvent that can determine the relationship between Is and Io most easily (the difference between Is and Io is most pronounced) is selected, The relationship between Is and Io may be determined based on the peak intensity. If the peak shift amount is small and the peaks before and after the shift appear to be a gentle mountain, peak separation may be performed using known means to determine the relationship between Is and Io.
 なお、ヘテロ元素を有する有機溶媒を複数種用いた電解液の振動分光スペクトルにおいては、カチオンと最も配位し易い有機溶媒(以下、「優先配位溶媒」ということがある。)のピークが他に優先してシフトする。ヘテロ元素を有する有機溶媒を複数種用いた電解液において、ヘテロ元素を有する有機溶媒全体に対する優先配位溶媒の質量%は、40%以上が好ましく、50%以上がより好ましく、60%以上がさらに好ましく、80%以上が特に好ましい。また、ヘテロ元素を有する有機溶媒を複数種用いた電解液において、ヘテロ元素を有する有機溶媒全体に対する優先配位溶媒の体積%は、40%以上が好ましく、50%以上がより好ましく、60%以上がさらに好ましく、80%以上が特に好ましい。 Note that in the vibrational spectroscopic spectrum of an electrolytic solution using a plurality of organic solvents having a hetero element, the peak of an organic solvent that is most easily coordinated with a cation (hereinafter sometimes referred to as “preferred coordination solvent”) is another. Shift in preference to. In an electrolytic solution using a plurality of organic solvents having a hetero element, the mass% of the preferential coordination solvent with respect to the entire organic solvent having a hetero element is preferably 40% or more, more preferably 50% or more, and further preferably 60% or more. 80% or more is particularly preferable. Further, in the electrolytic solution using a plurality of organic solvents having a hetero element, the volume% of the preferential coordination solvent with respect to the entire organic solvent having a hetero element is preferably 40% or more, more preferably 50% or more, and 60% or more. Is more preferable, and 80% or more is particularly preferable.
 本発明の電解液の振動分光スペクトルにおける上記2つのピーク強度の関係は、Is>2×Ioの条件を満たすことが好ましく、Is>3×Ioの条件を満たすことがより好ましく、Is>5×Ioの条件を満たすことがさらに好ましく、Is>7×Ioの条件を満たすことが特に好ましい。最も好ましいのは、本発明の電解液の振動分光スペクトルにおいて、有機溶媒本来のピークの強度Ioが観察されず、シフトピークの強度Isが観察される電解液である。当該電解液においては、電解液に含まれる有機溶媒の分子すべてが金属塩と完全に溶媒和していることを意味する。本発明の電解液は、電解液に含まれる有機溶媒の分子すべてが金属塩と完全に溶媒和している状態(Io=0の状態)が最も好ましい。 The relationship between the two peak intensities in the vibrational spectrum of the electrolytic solution of the present invention preferably satisfies the condition of Is> 2 × Io, more preferably satisfies the condition of Is> 3 × Io, and Is> 5 × It is more preferable that the condition of Io is satisfied, and it is particularly preferable that the condition of Is> 7 × Io is satisfied. Most preferred is an electrolytic solution in which the intensity Io of the peak inherent in the organic solvent is not observed and the intensity Is of the shift peak is observed in the vibrational spectrum of the electrolytic solution of the present invention. In the electrolytic solution, it means that all the molecules of the organic solvent contained in the electrolytic solution are completely solvated with the metal salt. The electrolyte solution of the present invention is most preferably in a state where all the molecules of the organic solvent contained in the electrolyte solution are completely solvated with the metal salt (Io = 0 state).
 本発明の電解液においては、金属塩と、ヘテロ元素を有する有機溶媒(または優先配位溶媒)が、相互作用を及ぼしていると推定される。具体的には、金属塩と、ヘテロ元素を有する有機溶媒(または優先配位溶媒)のヘテロ元素とが、配位結合を形成し、金属塩とヘテロ元素を有する有機溶媒(または優先配位溶媒)からなる安定なクラスターを形成していると推定される。このクラスターは、後述する実施例の結果からみて、概ね、金属塩1分子に対し、ヘテロ元素を有する有機溶媒(または優先配位溶媒)2分子が配位することにより形成されていると推定される。この点を考慮すると、本発明の電解液における、金属塩1モルに対するヘテロ元素を有する有機溶媒(または優先配位溶媒)のモル範囲は、1.4モル以上3.5モル未満が好ましく、1.5モル以上3.1モル以下がより好ましく、1.6モル以上3モル以下がさらに好ましい。 In the electrolytic solution of the present invention, it is presumed that the metal salt and the organic solvent (or preferential coordination solvent) having a hetero element have an interaction. Specifically, a metal salt and a hetero element of an organic solvent (or preferential coordination solvent) having a hetero element form a coordination bond, and the organic solvent (or preferential coordinating solvent) having a metal salt and a hetero element ) Is estimated to form a stable cluster. From the results of Examples described later, this cluster is presumed to be formed by coordination of two molecules of an organic solvent (or preferential coordination solvent) having a hetero element with one molecule of a metal salt. The Considering this point, the molar range of the organic solvent having a hetero element (or preferential coordination solvent) with respect to 1 mol of the metal salt in the electrolytic solution of the present invention is preferably 1.4 mol or more and less than 3.5 mol. More preferably, it is 0.5 mol or more and 3.1 mol or less, and 1.6 mol or more and 3 mol or less are still more preferable.
 本発明の電解液においては、概ね、金属塩1分子に対し、ヘテロ元素を有する有機溶媒(または優先配位溶媒)2分子が配位することによりクラスター形成されていると推定されるため、本発明の電解液の濃度(mol/L)は、金属塩および有機溶媒それぞれの分子量と、溶液にした場合の密度に依存する。そのため、本発明の電解液の濃度を一概に規定することは適当でない。 In the electrolytic solution of the present invention, it is presumed that a cluster is formed by coordination of two molecules of an organic solvent (or a preferential coordination solvent) having a hetero element with one molecule of a metal salt. The concentration (mol / L) of the electrolytic solution of the invention depends on the molecular weight of each of the metal salt and the organic solvent and the density when the solution is used. Therefore, it is not appropriate to prescribe the concentration of the electrolytic solution of the present invention.
 本発明の電解液の濃度(mol/L)を表1に個別に例示する。 Table 1 individually illustrates the concentration (mol / L) of the electrolytic solution of the present invention.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
 クラスターを形成している有機溶媒と、クラスターの形成に関与していない有機溶媒とは、それぞれの存在環境が異なる。そのため、振動分光測定において、クラスターを形成している有機溶媒由来のピークは、クラスターの形成に関与していない有機溶媒由来のピーク(有機溶媒本来のピーク)の観察される波数から、高波数側または低波数側にシフトして観察される。すなわち、シフトピークは、クラスターを形成している有機溶媒のピークに相当する。 The organic solvent that forms the cluster and the organic solvent that is not involved in the formation of the cluster have different environments. Therefore, in vibrational spectroscopy measurement, the peak derived from the organic solvent forming the cluster is higher than the observed wave number of the peak derived from the organic solvent not involved in the cluster formation (original peak of the organic solvent). Or it is observed shifted to the low wavenumber side. That is, the shift peak corresponds to the peak of the organic solvent forming the cluster.
 振動分光スペクトルとしては、IRスペクトルまたはラマンスペクトルを挙げることができる。IR測定の測定方法としては、ヌジョール法、液膜法などの透過測定方法、ATR法などの反射測定方法を挙げることができる。IRスペクトルまたはラマンスペクトルのいずれを選択するかについては、本発明の電解液の振動分光スペクトルにおいて、IsとIoの関係を判断しやすいスペクトルの方を選択すれば良い。なお、振動分光測定は、大気中の水分の影響を軽減または無視できる条件で行うのがよい。例えば、ドライルーム、グローブボックスなどの低湿度または無湿度条件下でIR測定を行うこと、または、電解液を密閉容器に入れたままの状態でラマン測定を行うのがよい。 As the vibrational spectrum, an IR spectrum or a Raman spectrum can be exemplified. Examples of the measurement method for IR measurement include transmission measurement methods such as Nujol method and liquid film method, and reflection measurement methods such as ATR method. As to whether to select the IR spectrum or the Raman spectrum, it is only necessary to select a spectrum in which the relationship between Is and Io can be easily determined in the vibrational spectrum of the electrolytic solution of the present invention. The vibrational spectroscopic measurement is preferably performed under conditions that can reduce or ignore the influence of moisture in the atmosphere. For example, IR measurement may be performed under low humidity or no humidity conditions such as in a dry room or a glove box, or Raman measurement may be performed with the electrolyte in a sealed container.
 ここで、金属塩としてLiTFSA、有機溶媒としてアセトニトリルを含む本発明の電解液におけるピークにつき、具体的に説明する。 Here, the peak in the electrolytic solution of the present invention containing LiTFSA as the metal salt and acetonitrile as the organic solvent will be specifically described.
 アセトニトリルのみをIR測定した場合、CおよびN間の三重結合の伸縮振動に由来するピークが通常2100~2400cm-1付近に観察される。 When only acetonitrile is measured by IR, a peak derived from stretching vibration of a triple bond between C and N is usually observed in the vicinity of 2100 to 2400 cm −1 .
 ここで、従来の技術常識に従い、アセトニトリル溶媒に対しLiTFSAを1mol/Lの濃度で溶解して電解液とした場合を想定する。アセトニトリル1Lは約19molに該当するので、従来の電解液1Lには、1molのLiTFSAと19molのアセトニトリルが存在する。そうすると、従来の電解液においては、LiTFSAと溶媒和している(Liに配位している)アセトニトリルと同時に、LiTFSAと溶媒和していない(Liに配位していない)アセトニトリルが多数存在する。さて、LiTFSAと溶媒和しているアセトニトリル分子と、LiTFSAと溶媒和していないアセトニトリル分子とは、アセトニトリル分子の置かれている環境が異なるので、IRスペクトルにおいては、両者のアセトニトリルピークが区別して観察される。より具体的には、LiTFSAと溶媒和していないアセトニトリルのピークは、アセトニトリルのみをIR測定した場合と同様の位置(波数)に観察されるが、他方、LiTFSAと溶媒和しているアセトニトリルのピークは、ピーク位置(波数)が高波数側にシフトして観察される。 Here, it is assumed that LiTFSA is dissolved in an acetonitrile solvent at a concentration of 1 mol / L to obtain an electrolytic solution according to conventional technical common sense. Since 1 L of acetonitrile corresponds to about 19 mol, 1 L of conventional electrolyte includes 1 mol of LiTFSA and 19 mol of acetonitrile. Then, in the conventional electrolyte, there are many acetonitriles that are not solvated with LiTFSA (not coordinated with Li) simultaneously with acetonitrile that is solvated with LiTFSA (coordinated with Li). . Now, since the acetonitrile molecule is different between the LiTFSA solvated acetonitrile molecule and the LiTFSA non-solvated acetonitrile molecule, in the IR spectrum, the acetonitrile peaks of both are distinguished and observed. Is done. More specifically, the peak of acetonitrile that is not solvated with LiTFSA is observed at the same position (wave number) as in the case of IR measurement of only acetonitrile, but the peak of acetonitrile that is solvated with LiTFSA. Is observed with the peak position (wave number) shifted to the high wave number side.
 そして、従来の電解液の濃度においては、LiTFSAと溶媒和していないアセトニトリルが多数存在するのであるから、従来の電解液の振動分光スペクトルにおいて、アセトニトリル本来のピークの強度Ioと、アセトニトリル本来のピークがシフトしたピークの強度Isとの関係は、Is<Ioとなる。 Since there are many acetonitriles that are not solvated with LiTFSA in the concentration of the conventional electrolyte, in the vibrational spectrum of the conventional electrolyte, the peak intensity Io of the original acetonitrile and the peak of the original acetonitrile The relationship with the intensity Is of the peak shifted is Is <Io.
 他方、本発明の電解液は従来の電解液と比較してLiTFSAの濃度が高く、かつ、電解液においてLiTFSAと溶媒和している(クラスターを形成している)アセトニトリル分子の数が、LiTFSAと溶媒和していないアセトニトリル分子の数よりも多い。そうすると、本発明の電解液の振動分光スペクトルにおける、アセトニトリル本来のピークの強度Ioと、アセトニトリル本来のピークがシフトしたピークの強度Isとの関係は、Is>Ioとなる。 On the other hand, the electrolytic solution of the present invention has a higher LiTFSA concentration than the conventional electrolytic solution, and the number of acetonitrile molecules solvated with LiTFSA (forming clusters) in the electrolytic solution is different from that of LiTFSA. More than the number of unsolvated acetonitrile molecules. Then, the relation between the intensity Io of the original peak of the acetonitrile and the intensity Is of the peak obtained by shifting the original peak of acetonitrile in the vibrational spectrum of the electrolytic solution of the present invention is Is> Io.
 表2に、本発明の電解液の振動分光スペクトルにおいて、IoおよびIsの算出に有用と考えられる有機溶媒の波数と、その帰属を例示する。なお、振動分光スペクトルの測定装置、測定環境、測定条件に因って、観察されるピークの波数が以下の波数と異なる場合があることを付け加えておく。 Table 2 exemplifies the wave numbers of organic solvents that are considered useful for the calculation of Io and Is and their attribution in the vibrational spectrum of the electrolytic solution of the present invention. It should be added that the wave number of the observed peak may be different from the following wave numbers depending on the measurement apparatus, measurement environment, and measurement conditions of the vibrational spectrum.
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
 有機溶媒の波数とその帰属につき、公知のデータを参考としてもよい。参考文献として、日本分光学会測定法シリーズ17 ラマン分光法、濱口宏夫、平川暁子、学会出版センター、231~249頁を挙げる。また、コンピュータを用いた計算でも、IoおよびIsの算出に有用と考えられる有機溶媒の波数と、有機溶媒と金属塩が配位した場合の波数シフトを予測することができる。例えば、Gaussian09(登録商標、ガウシアン社)を用い、密度汎関数をB3LYP、基底関数を6-311G++(d,p)として計算すればよい。当業者は、表2の記載、公知のデータ、コンピュータでの計算結果を参考にして、有機溶媒のピークを選定し、IoおよびIsを算出することができる。 公 知 Known data on the wave number of organic solvents and their attribution may be used as a reference. As references, the Spectroscopical Society of Japan Measurement Series 17, Raman Spectroscopy, Hiroo Higuchi, Atsuko Hirakawa, Academic Publishing Center, pages 231 to 249 are listed. In addition, the calculation using a computer can also predict the wave number of an organic solvent that is considered useful for the calculation of Io and Is and the wave number shift when the organic solvent and the metal salt are coordinated. For example, Gaussian 09 (registered trademark, Gaussian) may be used, and the density functional may be calculated as B3LYP and the basis function as 6-311G ++ (d, p). A person skilled in the art can calculate the Io and Is by selecting the peak of the organic solvent with reference to the description in Table 2, known data, and the calculation result in the computer.
 本発明の電解液は、従来の電解液と比較して、金属塩と有機溶媒の存在環境が異なり、かつ、金属塩濃度が高いため、電解液中の金属イオン輸送速度の向上(特に、金属がリチウムの場合、リチウム輸率の向上)、電極と電解液界面の反応速度の向上、電池のハイレート充放電時に起こる電解液の塩濃度の偏在の緩和、電気二重層容量の増大などが期待できる。後述するように、これらの優れた効果の少なくとも一部は、本発明の電解液に由来して負極および/または正極表面に形成される特殊構造のSEI皮膜によってもたらされると考えられる。そして、当該特殊構造のSEI皮膜と本発明の電解液との協働によって、上記した各種の優れた効果、例えば、電極と電解液界面との間での反応速度の向上が発揮されると考えられる。さらに、本発明の電解液においては、ヘテロ元素を有する有機溶媒の大半が金属塩とクラスターを形成していることから、電解液に含まれる有機溶媒の蒸気圧が低くなる。その結果として、本発明の電解液からの有機溶媒の揮発が低減できる。 The electrolytic solution of the present invention is different from the conventional electrolytic solution in that the presence environment of the metal salt and the organic solvent is different and the concentration of the metal salt is high, so that the metal ion transport rate in the electrolytic solution is improved (especially metal When Li is lithium, the lithium transport number is improved), the reaction rate between the electrode and the electrolyte solution is improved, the uneven distribution of the salt concentration of the electrolyte solution that occurs during high-rate charge / discharge of the battery, and the electric double layer capacity can be expected to increase . As will be described later, it is considered that at least a part of these excellent effects are brought about by the SEI film having a special structure derived from the electrolytic solution of the present invention and formed on the surface of the negative electrode and / or the positive electrode. And it is thought that the various excellent effects mentioned above, for example, the improvement of the reaction rate between an electrode and electrolyte solution interface are exhibited by cooperation with the SEI film of the special structure and the electrolyte solution of the present invention. It is done. Furthermore, in the electrolytic solution of the present invention, since most of the organic solvent having a hetero element forms a cluster with a metal salt, the vapor pressure of the organic solvent contained in the electrolytic solution is lowered. As a result, volatilization of the organic solvent from the electrolytic solution of the present invention can be reduced.
 本発明の電解液の製造方法を説明する。本発明の電解液は従来の電解液と比較して金属塩の含有量が多いため、固体(粉体)の金属塩に有機溶媒を加える製造方法では凝集体が得られてしまい、溶液状態の電解液を製造するのが困難である。よって、本発明の電解液の製造方法においては、有機溶媒に対し金属塩を徐々に加え、かつ、電解液の溶液状態を維持しながら製造することが好ましい。 The method for producing the electrolytic solution of the present invention will be described. Since the electrolytic solution of the present invention has a higher metal salt content than the conventional electrolytic solution, the production method in which an organic solvent is added to a solid (powder) metal salt results in the formation of aggregates. It is difficult to produce an electrolytic solution. Therefore, in the manufacturing method of the electrolyte solution of this invention, it is preferable to manufacture, adding a metal salt gradually with respect to an organic solvent, and maintaining the solution state of electrolyte solution.
 金属塩と有機溶媒の種類に因り、本発明の電解液は、従来考えられてきた飽和溶解度を超えて金属塩が有機溶媒に溶解している液体を包含する。そのような本発明の電解液の製造方法は、ヘテロ元素を有する有機溶媒と金属塩とを混合し、金属塩を溶解して、第1電解液を調製する第1溶解工程と、撹拌および/または加温条件下、前記第1電解液に前記金属塩を加え、前記金属塩を溶解し、過飽和状態の第2電解液を調製する第2溶解工程と、撹拌および/または加温条件下、前記第2電解液に前記金属塩を加え、前記金属塩を溶解し、第3電解液を調製する第3溶解工程を含む。 Depending on the type of metal salt and organic solvent, the electrolytic solution of the present invention includes a liquid in which the metal salt is dissolved in the organic solvent beyond the conventionally considered saturation solubility. Such a method for producing an electrolytic solution of the present invention includes a first dissolving step of preparing a first electrolytic solution by mixing an organic solvent having a hetero element and a metal salt, dissolving the metal salt, stirring and / or Alternatively, under heating conditions, the metal salt is added to the first electrolyte solution, the metal salt is dissolved, and a second electrolyte solution in a supersaturated state is prepared; and stirring and / or heating conditions, A third dissolving step of adding the metal salt to the second electrolytic solution, dissolving the metal salt, and preparing a third electrolytic solution;
 ここで、上記「過飽和状態」とは、撹拌および/または加温条件を解除した場合、または、振動等の結晶核生成エネルギーを与えた場合に、電解液から金属塩結晶が析出する状態のことを意味する。第2電解液は「過飽和状態」であり、第1電解液および第3電解液は「過飽和状態」でない。 Here, the “supersaturated state” refers to a state in which metal salt crystals are precipitated from the electrolyte when the stirring and / or heating conditions are canceled or when crystal nucleation energy such as vibration is applied. Means. The second electrolytic solution is “supersaturated”, and the first electrolytic solution and the third electrolytic solution are not “supersaturated”.
 換言すると、本発明の電解液の上記製造方法は、熱力学的に安定な液体状態であり従来の金属塩濃度を包含する第1電解液を経て、熱力学的に不安定な液体状態の第2電解液を経由し、そして、熱力学的に安定な新たな液体状態の第3電解液、すなわち本発明の電解液となる。 In other words, the above-described method for producing the electrolytic solution of the present invention is a thermodynamically stable liquid state, and passes through the first electrolytic solution containing the conventional metal salt concentration, and then the thermodynamically unstable liquid state. The second electrolytic solution passes through the two electrolytic solutions and becomes a thermodynamically stable new electrolytic third solution, that is, the electrolytic solution of the present invention.
 安定な液体状態の第3電解液は通常の条件で液体状態を保つことから、第3電解液においては、例えば、リチウム塩1分子に対し有機溶媒2分子で構成されこれらの分子間の強い配位結合によって安定化されたクラスターがリチウム塩の結晶化を阻害していると推定される。 Since the stable third electrolyte solution in a liquid state maintains a liquid state under normal conditions, the third electrolyte solution is composed of, for example, two molecules of an organic solvent for one lithium salt molecule, and a strong distribution between these molecules. It is presumed that the cluster stabilized by the coordinate bond inhibits the crystallization of the lithium salt.
 第1溶解工程は、ヘテロ原子を有する有機溶媒と金属塩とを混合し、金属塩を溶解して、第1電解液を調製する工程である。 The first dissolution step is a step of preparing a first electrolytic solution by mixing an organic solvent having a hetero atom and a metal salt to dissolve the metal salt.
 ヘテロ原子を有する有機溶媒と金属塩とを混合するためには、ヘテロ原子を有する有機溶媒に対し金属塩を加えても良いし、金属塩に対しヘテロ原子を有する有機溶媒を加えても良い。 In order to mix an organic solvent having a heteroatom and a metal salt, a metal salt may be added to the organic solvent having a heteroatom, or an organic solvent having a heteroatom may be added to the metal salt.
 第1溶解工程は、撹拌および/または加温条件下で行われるのが好ましい。撹拌速度については適宜設定すればよい。加温条件については、ウォーターバスまたはオイルバスなどの恒温槽で適宜制御するのが好ましい。金属塩の溶解時には溶解熱が発生するので、熱に不安定な金属塩を用いる場合には、温度条件を厳密に制御することが好ましい。また、あらかじめ、有機溶媒を冷却しておいても良いし、第1溶解工程を冷却条件下で行ってもよい。 The first dissolution step is preferably performed under stirring and / or heating conditions. What is necessary is just to set suitably about stirring speed. About heating conditions, it is preferable to control suitably with thermostats, such as a water bath or an oil bath. Since heat of dissolution is generated when the metal salt is dissolved, it is preferable to strictly control the temperature condition when using a metal salt that is unstable to heat. In addition, the organic solvent may be cooled in advance, or the first dissolution step may be performed under cooling conditions.
 第1溶解工程と第2溶解工程は連続して実施しても良いし、第1溶解工程で得た第1電解液を一旦保管(静置)しておき、一定時間経過した後に、第2溶解工程を実施しても良い。 The first dissolution step and the second dissolution step may be performed continuously, or the first electrolytic solution obtained in the first dissolution step is temporarily stored (standing), and after a certain time has passed, You may implement a melt | dissolution process.
 第2溶解工程は、撹拌および/または加温条件下、第1電解液に金属塩を加え、金属塩を溶解し、過飽和状態の第2電解液を調製する工程である。 The second dissolution step is a step of preparing a supersaturated second electrolyte solution by adding a metal salt to the first electrolyte solution under stirring and / or heating conditions to dissolve the metal salt.
 第2溶解工程は、熱力学的に不安定な過飽和状態の第2電解液を調製するため、撹拌および/または加温条件下で行うことが必須である。ミキサー等の撹拌器を伴った撹拌装置で第2溶解工程を行うことにより、撹拌条件下としても良いし、撹拌子と撹拌子を動作させる装置(スターラー)を用いて第2溶解工程を行うことにより、撹拌条件下としても良い。加温条件については、ウォーターバスまたはオイルバスなどの恒温槽で適宜制御するのが好ましい。もちろん、撹拌機能と加温機能を併せ持つ装置またはシステムを用いて第2溶解工程を行うことが特に好ましい。なお、ここでいう加温とは、対象物を常温(25℃)以上の温度に温めることを指す。加温温度は30℃以上であるのがより好ましく、35℃以上であるのがさらに好ましい。また、加温温度は、有機溶媒の沸点よりも低い温度であるのが良い。 It is essential to perform the second dissolution step under stirring and / or warming conditions in order to prepare a supersaturated second electrolyte solution that is thermodynamically unstable. By performing the second dissolution step with a stirrer with a stirrer such as a mixer, the stirring condition may be achieved, or the second dissolution step is performed using a stirrer and a device (stirrer) that operates the stirrer. Thus, the stirring condition may be used. About heating conditions, it is preferable to control suitably with thermostats, such as a water bath or an oil bath. Of course, it is particularly preferable to perform the second dissolution step using an apparatus or system having both a stirring function and a heating function. In addition, heating here refers to warming a target object to temperature more than normal temperature (25 degreeC). The heating temperature is more preferably 30 ° C. or higher, and further preferably 35 ° C. or higher. Further, the heating temperature is preferably lower than the boiling point of the organic solvent.
 第2溶解工程において、加えた金属塩が十分に溶解しない場合には、撹拌速度の増加および/またはさらなる加温を実施する。この場合には、第2溶解工程の電解液にヘテロ原子を有する有機溶媒を少量加えてもよい。 In the second dissolution step, if the added metal salt is not sufficiently dissolved, increase the stirring speed and / or further heating. In this case, a small amount of an organic solvent having a hetero atom may be added to the electrolytic solution in the second dissolution step.
 第2溶解工程で得た第2電解液を一旦静置すると金属塩の結晶が析出してしまうので、第2溶解工程と第3溶解工程は連続して実施するのが好ましい。 Since the crystal of the metal salt is deposited once the second electrolyte obtained in the second dissolution step is allowed to stand, the second dissolution step and the third dissolution step are preferably carried out continuously.
 第3溶解工程は、撹拌および/または加温条件下、第2電解液に金属塩を加え、金属塩を溶解し、第3電解液を調製する工程である。第3溶解工程では、過飽和状態の第2電解液に金属塩を加え、溶解する必要があるので、第2溶解工程と同様に撹拌および/または加温条件下で行うことが必須である。具体的な撹拌および/または加温条件は、第2溶解工程の条件と同様である。 The third dissolution step is a step of preparing a third electrolyte solution by adding a metal salt to the second electrolyte solution under stirring and / or heating conditions to dissolve the metal salt. In the third dissolution step, it is necessary to add a metal salt to the supersaturated second electrolytic solution and dissolve it. Therefore, it is essential to perform the stirring and / or heating conditions as in the second dissolution step. Specific stirring and / or heating conditions are the same as those in the second dissolution step.
 第1溶解工程、第2溶解工程および第3溶解工程を通じて加えた有機溶媒と金属塩とのモル比が概ね2:1程度となれば、第3電解液(本発明の電解液)の製造が終了する。撹拌および/または加温条件を解除しても、本発明の電解液から金属塩結晶は析出しない。これらの事情からみて、本発明の電解液は、例えば、リチウム塩1分子に対し有機溶媒2分子からなり、これらの分子間の強い配位結合によって安定化されたクラスターを形成していると推定される。 If the molar ratio of the organic solvent and the metal salt added through the first dissolving step, the second dissolving step, and the third dissolving step is about 2: 1, the production of the third electrolytic solution (the electrolytic solution of the present invention) is completed. finish. Even when the stirring and / or heating conditions are canceled, the metal salt crystals are not precipitated from the electrolytic solution of the present invention. In view of these circumstances, the electrolytic solution of the present invention is composed of, for example, two molecules of an organic solvent for one molecule of a lithium salt, and is presumed to form a cluster stabilized by a strong coordinate bond between these molecules. Is done.
 なお、本発明の電解液を製造するにあたり、金属塩と有機溶媒の種類に因り、各溶解工程での処理温度において、上記過飽和状態を経由しない場合であっても、上記第1~3溶解工程で述べた具体的な溶解手段を用いて本発明の電解液を適宜製造することができる。 In producing the electrolytic solution of the present invention, depending on the types of metal salt and organic solvent, the first to third dissolving steps can be performed even if the supersaturated state is not passed at the treatment temperature in each dissolving step. The electrolytic solution of the present invention can be appropriately produced using the specific dissolution means described in 1.
 また、本発明の電解液を製造する方法においては、製造途中の電解液を振動分光測定する振動分光測定工程を有するのが好ましい。具体的な振動分光測定工程としては、例えば、製造途中の各電解液を一部サンプリングして振動分光測定に供する方法でも良いし、各電解液をin situ(その場)で振動分光測定する方法でも良い。電解液をin situで振動分光測定する方法としては、透明なフローセルに製造途中の電解液を導入して振動分光測定する方法、または、透明な製造容器を用いて該容器外からラマン測定する方法を挙げることができる。 In addition, the method for producing the electrolytic solution of the present invention preferably includes a vibrational spectroscopic measurement step of performing vibrational spectroscopic measurement of the electrolytic solution being manufactured. As a specific vibration spectroscopic measurement step, for example, a method of sampling a part of each electrolytic solution in the middle of production and using it for vibration spectroscopic measurement, or a method of performing spectroscopic spectroscopic measurement of each electrolytic solution in situ (situ) But it ’s okay. As a method for in-vitro vibrational spectroscopic measurement of an electrolytic solution, a method of introducing an electrolytic solution in the middle of production into a transparent flow cell and performing vibrational spectroscopic measurement, or a method of performing Raman measurement from outside the container using a transparent production vessel Can be mentioned.
 本発明の電解液の製造方法に振動分光測定工程を含めることにより、電解液におけるIsとIoとの関係を製造途中で確認できるため、製造途中の電解液が本発明の電解液に達したのか否かを判断することができるし、また、製造途中の電解液が本発明の電解液に達していない場合にどの程度の量の金属塩を追加すれば本発明の電解液に達するのかを把握することができる。 Since the relationship between Is and Io in the electrolytic solution can be confirmed during the production by including the vibrational spectroscopic measurement step in the method for producing the electrolytic solution of the present invention, whether the electrolytic solution during the production reaches the electrolytic solution of the present invention. It is possible to determine whether or not the amount of metal salt added to reach the electrolytic solution of the present invention when the electrolytic solution being manufactured does not reach the electrolytic solution of the present invention. can do.
 本発明の電解液には、上記ヘテロ元素を有する有機溶媒以外に、低極性(低誘電率)または低ドナー数であって、金属塩と特段の相互作用を示さない溶媒、すなわち、本発明の電解液における上記クラスターの形成および維持に影響を与えない溶媒を加えることができる。このような溶媒を本発明の電解液に加えることにより、本発明の電解液の上記クラスターの形成を保持したままで、電解液の粘度を低くする効果が期待できる。 In the electrolyte solution of the present invention, in addition to the organic solvent having a hetero element, the solvent has a low polarity (low dielectric constant) or a low donor number and does not exhibit a special interaction with a metal salt, that is, the present invention. A solvent that does not affect the formation and maintenance of the clusters in the electrolyte can be added. By adding such a solvent to the electrolytic solution of the present invention, an effect of lowering the viscosity of the electrolytic solution can be expected while maintaining the formation of the cluster of the electrolytic solution of the present invention.
 金属塩と特段の相互作用を示さない溶媒としては、具体的にベンゼン、トルエン、エチルベンゼン、o-キシレン、m-キシレン、p-キシレン、1-メチルナフタレン、ヘキサン、ヘプタン、シクロヘキサンを例示することができる。 Specific examples of the solvent that does not exhibit a special interaction with the metal salt include benzene, toluene, ethylbenzene, o-xylene, m-xylene, p-xylene, 1-methylnaphthalene, hexane, heptane, and cyclohexane. it can.
 また、本発明の電解液には、上記ヘテロ元素を有する有機溶媒以外に、難燃性の溶媒を加えることができる。難燃性の溶媒を本発明の電解液に加えることにより、本発明の電解液の安全度をさらに高めることができる。難燃性の溶媒としては、四塩化炭素、テトラクロロエタン、ハイドロフルオロエーテルなどのハロゲン系溶媒、リン酸トリメチル、リン酸トリエチルなどのリン酸誘導体を例示することができる。 In addition to the organic solvent having a hetero element, a flame retardant solvent can be added to the electrolytic solution of the present invention. By adding a flame retardant solvent to the electrolytic solution of the present invention, the safety of the electrolytic solution of the present invention can be further increased. Examples of the flame retardant solvent include halogen solvents such as carbon tetrachloride, tetrachloroethane, and hydrofluoroether, and phosphoric acid derivatives such as trimethyl phosphate and triethyl phosphate.
 さらに、本発明の電解液をポリマーや無機フィラーと混合し混合物とすると、当該混合物が電解液を封じ込め、擬似固体電解質となる。擬似固体電解質を電池の電解液として用いることで、電池における電解液の液漏れを抑制することができる。 Furthermore, when the electrolytic solution of the present invention is mixed with a polymer or an inorganic filler to form a mixture, the mixture contains the electrolytic solution and becomes a pseudo solid electrolyte. By using the pseudo-solid electrolyte as the battery electrolyte, leakage of the electrolyte in the battery can be suppressed.
 上記ポリマーとしては、リチウムイオン二次電池などの非水電解質二次電池に使用されるポリマーや一般的な化学架橋したポリマーを採用することができる。特に、ポリフッ化ビニリデンやポリヘキサフルオロプロピレンなど電解液を吸収しゲル化し得るポリマーや、ポリエチレンオキシドなどのポリマーにイオン導電性基を導入したものが好適である。 As the polymer, a polymer used for a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery or a general chemically crosslinked polymer can be used. In particular, a polymer that can absorb an electrolyte such as polyvinylidene fluoride and polyhexafluoropropylene and gel can be used, and a polymer such as polyethylene oxide in which an ion conductive group is introduced.
 具体的なポリマーとしては、ポリメチルアクリレート、ポリメチルメタクリレート、ポリエチレンオキシド、ポリプロピレンオキシド、ポリアクリロニトリル、ポリフッ化ビニリデン、ポリエチレングリコールジメタクリレート、ポリエチレングリコールアクリレート、ポリグリシドール、ポリテトラフルオロエチレン、ポリヘキサフルオロプロピレン、ポリシロキサン、ポリ酢酸ビニル、ポリビニルアルコール、ポリアクリル酸、ポリメタクリル酸、ポリイタコン酸、ポリフマル酸、ポリクロトン酸、ポリアンゲリカ酸、カルボキシメチルセルロースなどのポリカルボン酸、スチレン-ブタジエンゴム、ニトリル-ブタジエンゴム、ポリスチレン、ポリカーボネート、無水マレイン酸とグリコール類を共重合した不飽和ポリエステル、置換基を有するポリエチレンオキシド誘導体、フッ化ビニリデンとヘキサフルオロプロピレンとの共重合体を例示できる。また、上記ポリマーとして、上記具体的なポリマーを構成する二種類以上のモノマーを共重合させた共重合体を選択しても良い。 Specific polymers include polymethyl acrylate, polymethyl methacrylate, polyethylene oxide, polypropylene oxide, polyacrylonitrile, polyvinylidene fluoride, polyethylene glycol dimethacrylate, polyethylene glycol acrylate, polyglycidol, polytetrafluoroethylene, polyhexafluoropropylene, Polycarboxylic acid such as polysiloxane, polyvinyl acetate, polyvinyl alcohol, polyacrylic acid, polymethacrylic acid, polyitaconic acid, polyfumaric acid, polycrotonic acid, polyangelic acid, carboxymethylcellulose, styrene-butadiene rubber, nitrile-butadiene rubber, polystyrene , Polycarbonate, unsaturated polyester copolymerized with maleic anhydride and glycols, Polyethylene oxide derivative having a group, a copolymer of vinylidene fluoride and hexafluoropropylene can be exemplified. Further, as the polymer, a copolymer obtained by copolymerizing two or more monomers constituting the specific polymer may be selected.
 上記ポリマーとして、多糖類も好適である。具体的な多糖類として、グリコーゲン、セルロース、キチン、アガロース、カラギーナン、ヘパリン、ヒアルロン酸、ペクチン、アミロペクチン、キシログルカン、アミロースを例示できる。また、これら多糖類を含む材料を上記ポリマーとして採用してもよく、当該材料として、アガロースなどの多糖類を含む寒天を例示することができる。 Polysaccharides are also suitable as the polymer. Specific examples of the polysaccharide include glycogen, cellulose, chitin, agarose, carrageenan, heparin, hyaluronic acid, pectin, amylopectin, xyloglucan, and amylose. Moreover, you may employ | adopt the material containing these polysaccharides as said polymer, The agar containing polysaccharides, such as agarose, can be illustrated as the said material.
 上記無機フィラーとしては、酸化物や窒化物などの無機セラミックスが好ましい。 The inorganic filler is preferably an inorganic ceramic such as oxide or nitride.
 無機セラミックスはその表面に親水性および疎水性の官能基を有している。そのため、当該官能基が電解液を引き付けることにより、無機セラミックス内に導電性通路が形成され得る。さらに、電解液で分散した無機セラミックスは前記官能基により無機セラミックス同士のネットワークを形成し、電解液を封じ込める役割を果たし得る。無機セラミックスのこのような機能により、電池における電解液の液漏れをさらに好適に抑制することができる。無機セラミックスの上記機能を好適に発揮するために、無機セラミックスは粒子形状のものが好ましく、特にその粒子径がナノ水準のものが好ましい。 Inorganic ceramics have hydrophilic and hydrophobic functional groups on the surface. Therefore, when the functional group attracts the electrolytic solution, a conductive path can be formed in the inorganic ceramic. Furthermore, the inorganic ceramics dispersed in the electrolytic solution can form a network between the inorganic ceramics by the functional groups and serve to contain the electrolytic solution. With such a function of the inorganic ceramics, it is possible to more suitably suppress the leakage of the electrolytic solution in the battery. In order to suitably exhibit the above functions of the inorganic ceramics, the inorganic ceramics preferably have a particle shape, and particularly preferably have a particle size of nano level.
 無機セラミックスの種類としては、一般的なアルミナ、シリカ、チタニア、ジルコニア、リチウムリン酸塩などを挙げることができる。また、無機セラミックス自体にリチウム伝導性があるものでも良く、具体的には、LiN、LiI、LiI-LiN-LiOH、LiI-LiS-P、LiI-LiS-P、LiI-LiS-B、LiO-B、LiO-V-SiO、LiO-B-P、LiO-B-ZnO、LiO-Al-TiO-SiO-P、LiTi(PO、Li-βAl、LiTaOを例示することができる。 Examples of the inorganic ceramics include general alumina, silica, titania, zirconia, and lithium phosphate. Further, the inorganic ceramic itself may be lithium conductive, and specifically, Li 3 N, LiI, LiI—Li 3 N—LiOH, LiI—Li 2 S—P 2 O 5 , LiI—Li 2 S —P 2 S 5 , LiI—Li 2 S—B 2 S 3 , Li 2 O—B 2 S 3 , Li 2 O—V 2 O 3 —SiO 2 , Li 2 O—B 2 O 3 —P 2 O 5 , Li 2 O—B 2 O 3 —ZnO, Li 2 O—Al 2 O 3 —TiO 2 —SiO 2 —P 2 O 5 , LiTi 2 (PO 4 ) 3 , Li—βAl 2 O 3 , LiTaO 3 Can be illustrated.
 無機フィラーとしてガラスセラミックスを採用してもよい。ガラスセラミックスはイオン性液体を封じ込めることができるので、本発明の電解液に対しても同様の効果を期待できる。ガラスセラミックスとしては、xLiS-(1-x)Pで表される化合物、ならびに、当該化合物のSの一部を他の元素で置換したもの、および、当該化合物のPの一部をゲルマニウムに置換したものを例示できる。 Glass ceramics may be employed as the inorganic filler. Since glass ceramics can contain an ionic liquid, the same effect can be expected for the electrolytic solution of the present invention. Glass ceramics include compounds represented by xLi 2 S- (1-x) P 2 S 5 , those obtained by substituting part of S of the compound with other elements, and compounds of P of the compound. Examples in which the part is replaced with germanium can be exemplified.
 本発明の電解液における密度d(g/cm)は、好ましくはd≧1.2またはd≦2.2であり、1.2≦d≦2.2の範囲内がより好ましく、1.24≦d≦2.0の範囲内がより好ましく、1.26≦d≦1.8の範囲内がさらに好ましく、1.27≦d≦1.6の範囲内が特に好ましい。なお、本発明の電解液における密度d(g/cm)は、20℃での密度を意味する。以下に説明するd/cは上記dを塩濃度c(mol/L)で除した値である。 The density d (g / cm 3 ) in the electrolytic solution of the present invention is preferably d ≧ 1.2 or d ≦ 2.2, more preferably 1.2 ≦ d ≦ 2.2. A range of 24 ≦ d ≦ 2.0 is more preferable, a range of 1.26 ≦ d ≦ 1.8 is more preferable, and a range of 1.27 ≦ d ≦ 1.6 is particularly preferable. The density d (g / cm 3 ) in the electrolytic solution of the present invention means the density at 20 ° C. D / c described below is a value obtained by dividing the above d by the salt concentration c (mol / L).
 本発明の電解液におけるd/cは0.15≦d/c≦0.71であり、0.15≦d/c≦0.56の範囲内が好ましく、0.25≦d/c≦0.56の範囲内がより好ましく、0.26≦d/c≦0.50の範囲内がさらに好ましく、0.27≦d/c≦0.47の範囲内が特に好ましい。 In the electrolytic solution of the present invention, d / c is 0.15 ≦ d / c ≦ 0.71, preferably 0.15 ≦ d / c ≦ 0.56, and 0.25 ≦ d / c ≦ 0. Within the range of .56, more preferably within the range of 0.26 ≦ d / c ≦ 0.50, and particularly preferably within the range of 0.27 ≦ d / c ≦ 0.47.
 本発明の電解液におけるd/cは、金属塩と有機溶媒を特定した場合でも規定することができる。例えば、金属塩としてLiTFSA、有機溶媒としてDMEを選択した場合には、d/cは0.42≦d/c≦0.56の範囲内が好ましく、0.44≦d/c≦0.52の範囲内がより好ましい。金属塩としてLiTFSA、有機溶媒としてANを選択した場合には、d/cは0.35≦d/c≦0.41の範囲内が好ましく、0.36≦d/c≦0.39の範囲内がより好ましい。金属塩としてLiFSA、有機溶媒としてDMEを選択した場合には、d/cは0.32≦d/c≦0.46の範囲内が好ましく、0.34≦d/c≦0.42の範囲内がより好ましい。金属塩としてLiFSA、有機溶媒としてANを選択した場合には、d/cは0.25≦d/c≦0.48の範囲内が好ましく、0.25≦d/c≦0.38の範囲がより好ましく、0.25≦d/c≦0.31の範囲内がさらに好ましく、0.26≦d/c≦0.29の範囲内がなお好ましい。金属塩としてLiFSA、有機溶媒としてDMCを選択した場合には、d/cは0.32≦d/c≦0.46の範囲内が好ましく、0.34≦d/c≦0.42の範囲内がより好ましい。金属塩としてLiFSA、有機溶媒としてEMCを選択した場合には、d/cは0.34≦d/c≦0.50の範囲内が好ましく、0.37≦d/c≦0.45の範囲内がより好ましい。金属塩としてLiFSA、有機溶媒としてDECを選択した場合には、d/cは0.36≦d/c≦0.54の範囲内が好ましく、0.39≦d/c≦0.48の範囲内がより好ましい。 D / c in the electrolytic solution of the present invention can be defined even when a metal salt and an organic solvent are specified. For example, when LiTFSA is selected as the metal salt and DME is selected as the organic solvent, d / c is preferably within the range of 0.42 ≦ d / c ≦ 0.56, and 0.44 ≦ d / c ≦ 0.52 The range of is more preferable. When LiTFSA is selected as the metal salt and AN is selected as the organic solvent, d / c is preferably in the range of 0.35 ≦ d / c ≦ 0.41, and 0.36 ≦ d / c ≦ 0.39. The inside is more preferable. When LiFSA is selected as the metal salt and DME is selected as the organic solvent, d / c is preferably in the range of 0.32 ≦ d / c ≦ 0.46, and in the range of 0.34 ≦ d / c ≦ 0.42. The inside is more preferable. When LiFSA is selected as the metal salt and AN is selected as the organic solvent, d / c is preferably in the range of 0.25 ≦ d / c ≦ 0.48, and in the range of 0.25 ≦ d / c ≦ 0.38. Is more preferable, the range of 0.25 ≦ d / c ≦ 0.31 is still more preferable, and the range of 0.26 ≦ d / c ≦ 0.29 is still more preferable. When LiFSA is selected as the metal salt and DMC is selected as the organic solvent, d / c is preferably in the range of 0.32 ≦ d / c ≦ 0.46, and in the range of 0.34 ≦ d / c ≦ 0.42. The inside is more preferable. When LiFSA is selected as the metal salt and EMC is selected as the organic solvent, d / c is preferably in the range of 0.34 ≦ d / c ≦ 0.50, and in the range of 0.37 ≦ d / c ≦ 0.45. The inside is more preferable. When LiFSA is selected as the metal salt and DEC is selected as the organic solvent, d / c is preferably in the range of 0.36 ≦ d / c ≦ 0.54, and in the range of 0.39 ≦ d / c ≦ 0.48. The inside is more preferable.
 本発明の電解液は、従来の電解液と比較して、金属塩と有機溶媒の存在環境が異なり、密度が高いため、電解液中の金属イオン輸送速度の向上(特に、金属がリチウムの場合、リチウム輸率の向上)、電極と電解液界面の反応速度の向上、電池のハイレート充放電時に起こる電解液の塩濃度の偏在の緩和、電気二重層容量増大などが期待できる。さらに、本発明の電解液においては、密度が高いことから、電解液に含まれる有機溶媒の蒸気圧が低くなる。その結果として、本発明の電解液からの有機溶媒の揮発が低減できる。 Compared with conventional electrolytes, the electrolyte solution of the present invention is different in the environment in which the metal salt and the organic solvent are present and has a high density, so that the metal ion transport rate in the electrolyte solution is improved (particularly when the metal is lithium , Improvement in lithium transport number), improvement in the reaction rate between the electrode and the electrolyte solution, relaxation of uneven distribution of the salt concentration of the electrolyte that occurs during high-rate charge / discharge of the battery, and increase in the electric double layer capacity can be expected. Furthermore, in the electrolytic solution of the present invention, since the density is high, the vapor pressure of the organic solvent contained in the electrolytic solution is lowered. As a result, volatilization of the organic solvent from the electrolytic solution of the present invention can be reduced.
 また、このような本発明の電解液の粘度は、従来の電解液の粘度と比較して高い。このため、本発明の電解液を用いた本発明の非水電解質二次電池であれば、仮に電池が破損したとしても、電解液漏れが抑制される。また、従来の電解液を用いた非水電解質二次電池は、高速充放電サイクル時に容量減少が顕著であった。その理由の一つとして、急速に充放電を繰り返した際の電解液中に生じたLi濃度ムラに因り、電極との反応界面に十分な量のLiを電解液が供給できなくなったこと、つまり、電解液のLi濃度の偏在が考えられる。しかしながら、本発明の電解液の金属濃度は、従来の電解液に対して高い。例えば本発明の電解液の好ましいLi濃度は、一般的な電解液のLi濃度の2~5倍程度である。このようにLiを高濃度で含む本発明の電解液においては、Liの偏在が軽減されると考えられ、その結果、高速充放電サイクル時の容量低下が抑制されると考えられる。また、本発明の電解液が高粘度であることにより、電極界面における電解液の保液性が向上し、電極界面で電解液が不足する状態(いわゆる液枯れ状態)を抑制することも、高速充放電サイクル時の容量低下が抑制された一因と考えられる。 In addition, the viscosity of the electrolytic solution of the present invention is higher than that of the conventional electrolytic solution. For this reason, if the nonaqueous electrolyte secondary battery of the present invention using the electrolytic solution of the present invention is used, even if the battery is damaged, electrolyte leakage is suppressed. Moreover, the capacity | capacitance reduction of the nonaqueous electrolyte secondary battery using the conventional electrolyte solution was remarkable at the time of a high-speed charging / discharging cycle. One reason for this is that due to the uneven Li concentration generated in the electrolyte when rapidly charging and discharging, the electrolyte cannot supply a sufficient amount of Li to the reaction interface with the electrode. The uneven distribution of Li concentration in the electrolytic solution can be considered. However, the metal concentration of the electrolytic solution of the present invention is higher than that of the conventional electrolytic solution. For example, the preferable Li concentration of the electrolytic solution of the present invention is about 2 to 5 times the Li concentration of a general electrolytic solution. Thus, in the electrolytic solution of the present invention containing Li at a high concentration, it is considered that the uneven distribution of Li is reduced, and as a result, the capacity reduction during the high-speed charge / discharge cycle is suppressed. In addition, since the electrolytic solution of the present invention has a high viscosity, the liquid retaining property of the electrolytic solution at the electrode interface is improved, and the state where the electrolytic solution is insufficient at the electrode interface (so-called liquid withdrawn state) can be suppressed. This is considered to be one of the reasons that the capacity decrease during the charge / discharge cycle is suppressed.
 本発明の電解液の粘度η(mPa・s)について述べると、10<η<500の範囲が好ましく、12<η<400の範囲がより好ましく、15<η<300の範囲がさらに好ましく、18<η<150の範囲が特に好ましく、20<η<140の範囲が最も好ましい。 Regarding the viscosity η (mPa · s) of the electrolytic solution of the present invention, a range of 10 <η <500 is preferable, a range of 12 <η <400 is more preferable, a range of 15 <η <300 is further preferable, and 18 A range of <η <150 is particularly preferable, and a range of 20 <η <140 is most preferable.
 また、電解液のイオン伝導度σ(mS/cm)は高ければ高いほど、電解液中でイオンが移動し易い。このため、このような電解液は優れた電池の電解液となり得る。本発明の電解液のイオン伝導度σ(mS/cm)について述べると、1≦σであるのが好ましい。本発明の非水電解質二次電池における電解液のイオン伝導度σ(mS/cm)につき、あえて、上限を含めた好適な範囲を示すと、2<σ<200の範囲が好ましく、3<σ<100の範囲がより好ましく、4<σ<50の範囲がさらに好ましく、5<σ<35の範囲が特に好ましい。 Also, the higher the ion conductivity σ (mS / cm) of the electrolytic solution, the easier the ions move in the electrolytic solution. For this reason, such an electrolyte can be an excellent battery electrolyte. The ion conductivity σ (mS / cm) of the electrolytic solution of the present invention is preferably 1 ≦ σ. Regarding the ionic conductivity σ (mS / cm) of the electrolyte solution in the nonaqueous electrolyte secondary battery of the present invention, a preferable range including the upper limit is preferably 2 <σ <200, and preferably 3 <σ. A range of <100 is more preferred, a range of 4 <σ <50 is more preferred, and a range of 5 <σ <35 is particularly preferred.
 ところで、本発明の非水電解質二次電池(1)における負極および/または正極の表面にはS,O含有皮膜が形成されている。多くの場合には、非水電解質二次電池(2)の負極および/または正極の表面にもS,O含有皮膜が形成されている。後述するように、この皮膜はSおよびOを含み、少なくともS=O構造を有する。そして、このS,O含有皮膜は、S=O構造を有するため、電解液に由来するものであると考えられる。本発明の電解液の中では、通常の電解液に比べて、Liカチオンとアニオンとが近くに存在すると考えられる。このためアニオンはLiカチオンからの静電的な影響を強く受けることで優先的に還元分解される。一般的な電解液を用いた一般的な非水電解質二次電池においては、電解液に含まれる有機溶媒(例えばEC:エチレンカーボネート等)が還元分解され、当該有機溶媒の分解生成物によってSEI皮膜が構成される。しかし、上述したように本発明の非水電解質二次電池に含まれる本発明の電解液においてはアニオンが優先的に還元分解される。このため、本発明の非水電解質二次電池におけるSEI皮膜、つまりS,O含有皮膜には、アニオンに由来するS=O構造が多く含まれると考えられる。つまり、通常の電解液を用いた通常の非水電解質二次電池においては、EC等の有機溶媒の分解物に由来するSEI皮膜が電極表面に定着する。一方、本発明の電解液を用いた本発明の非水電解質二次電池においては、主として金属塩のアニオンに由来するSEI皮膜が電極表面に定着する。 Incidentally, an S, O-containing film is formed on the surface of the negative electrode and / or the positive electrode in the nonaqueous electrolyte secondary battery (1) of the present invention. In many cases, an S, O-containing film is also formed on the surface of the negative electrode and / or the positive electrode of the nonaqueous electrolyte secondary battery (2). As will be described later, this film contains S and O, and has at least an S═O structure. And since this S, O containing film | membrane has a S = O structure, it is thought that it originates in electrolyte solution. In the electrolytic solution of the present invention, it is considered that the Li cation and the anion are present in the vicinity as compared with a normal electrolytic solution. For this reason, the anion is preferentially reduced and decomposed by being strongly affected by the electrostatic influence from the Li cation. In a general non-aqueous electrolyte secondary battery using a general electrolytic solution, an organic solvent (for example, EC: ethylene carbonate) contained in the electrolytic solution is reduced and decomposed, and an SEI film is formed by a decomposition product of the organic solvent. Is configured. However, as described above, in the electrolytic solution of the present invention included in the nonaqueous electrolyte secondary battery of the present invention, anions are preferentially reduced and decomposed. For this reason, it is considered that the SEI film, that is, the S, O-containing film in the non-aqueous electrolyte secondary battery of the present invention contains a lot of S═O structures derived from anions. That is, in a normal nonaqueous electrolyte secondary battery using a normal electrolyte solution, an SEI film derived from a decomposition product of an organic solvent such as EC is fixed on the electrode surface. On the other hand, in the nonaqueous electrolyte secondary battery of the present invention using the electrolytic solution of the present invention, the SEI film mainly derived from the anion of the metal salt is fixed on the electrode surface.
 また、理由は定かではないが、本発明の非水電解質二次電池におけるS,O含有皮膜は充放電に伴って状態変化する。例えば、後述するように、充放電の状態によってはS,O含有皮膜の厚さやS、O等の元素の割合が変化する場合がある。このため、本発明の非水電解質二次電池におけるS,O含有皮膜には、上述したアニオンの分解物に由来し皮膜中に定着する部分(以下、必要に応じて定着部と呼ぶ)と、充放電に伴って可逆的に増減する部分(以下、必要に応じて吸着部と呼ぶ)とが存在すると考えられる。そして吸着部は、定着部と同様に金属塩のアニオンに由来するS=O等の構造を有すると推測される。 Moreover, although the reason is not certain, the state of the S, O-containing film in the nonaqueous electrolyte secondary battery of the present invention changes with charge / discharge. For example, as will be described later, depending on the state of charge and discharge, the thickness of the S, O-containing film and the ratio of elements such as S, O may change. For this reason, the S, O-containing film in the nonaqueous electrolyte secondary battery of the present invention is derived from the above-described decomposition product of anions and fixed in the film (hereinafter referred to as a fixing unit as required), It is considered that there is a portion that reversibly increases / decreases with charge / discharge (hereinafter referred to as an adsorption portion as necessary). The adsorption part is presumed to have a structure such as S═O derived from the anion of the metal salt as in the fixing part.
 なお、S,O含有皮膜は電解液の分解物で構成され、その他吸着物を含むと考えられるため、S,O含有皮膜の大部分(または全て)は非水電解質二次電池の初回充放電時以降に生成すると考えられる。つまり、本発明の非水電解質二次電池は、使用時において、負極の表面および/または正極の表面にS,O含有皮膜を有する。S,O含有皮膜のその他の構成成分は、電解液に含まれる硫黄および酸素以外の成分や、負極の組成等に応じて種々に異なる。また、当該S,O含有皮膜はS=O構造を含みさえすれば良く、その含有割合は特に限定されない。さらに、S,O含有皮膜に含まれるS=O構造以外の成分および量は特に限定されない。そして、S,O含有皮膜は負極表面にのみ形成されても良いし、正極表面にのみ形成されても良い。しかしながら、上述したようにS,O含有皮膜は本発明の電解液に含まれる金属塩のアニオンに由来すると考えられるため、当該金属塩のアニオンに由来する成分をその他の成分よりも多く含むのが好ましい。また、S,O含有皮膜は負極表面および正極表面の両方に形成されるのが好ましい。以下、必要に応じて、負極の表面に形成されたS,O含有皮膜を負極S,O含有皮膜と呼び、正極の表面に形成されたS,O含有皮膜を正極S,O含有皮膜と呼ぶ。 Since the S, O-containing film is composed of a decomposition product of the electrolytic solution and is thought to contain other adsorbents, most (or all) of the S, O-containing film is the first charge / discharge of the nonaqueous electrolyte secondary battery. It is considered to be generated after the hour. That is, the nonaqueous electrolyte secondary battery of the present invention has an S, O-containing film on the surface of the negative electrode and / or the surface of the positive electrode in use. Other constituent components of the S, O-containing coating are variously different depending on components other than sulfur and oxygen contained in the electrolytic solution, the composition of the negative electrode, and the like. Moreover, the said S, O containing film should just contain S = O structure, and the content rate is not specifically limited. Furthermore, components and amounts other than the S═O structure contained in the S, O-containing coating are not particularly limited. The S, O-containing film may be formed only on the negative electrode surface, or may be formed only on the positive electrode surface. However, as described above, since the S, O-containing film is considered to be derived from the anion of the metal salt contained in the electrolytic solution of the present invention, it contains more components derived from the anion of the metal salt than the other components. preferable. In addition, the S, O-containing film is preferably formed on both the negative electrode surface and the positive electrode surface. Hereinafter, the S, O-containing film formed on the surface of the negative electrode is referred to as the negative electrode S, O-containing film, and the S, O-containing film formed on the surface of the positive electrode is referred to as the positive electrode S, O-containing film as necessary. .
 上述したように、本発明の電解液における金属塩としてイミド塩を好ましく用いることができる。従来から、電解液にイミド塩を添加する技術は知られており、この種の電解液を用いた非水電解質二次電池においては、正極および/または負極上の皮膜は、電解液の有機溶媒分解物に由来する化合物に加え、イミド塩由来の化合物、つまりSを含む化合物を含むことが知られている。例えば特開2013-145732には、この皮膜に一部含まれるイミド塩由来の成分によって、非水電解質二次電池の内部抵抗の増大を抑制しつつ非水電解質二次電池の耐久性を向上させ得ることが紹介されている。 As described above, an imide salt can be preferably used as the metal salt in the electrolytic solution of the present invention. Conventionally, a technique for adding an imide salt to an electrolytic solution is known. In a non-aqueous electrolyte secondary battery using this type of electrolytic solution, the coating on the positive electrode and / or the negative electrode is an organic solvent of the electrolytic solution. In addition to compounds derived from decomposition products, it is known to include compounds derived from imide salts, that is, compounds containing S. For example, in JP2013-145732A, a component derived from an imide salt partially contained in this film improves the durability of the nonaqueous electrolyte secondary battery while suppressing an increase in the internal resistance of the nonaqueous electrolyte secondary battery. It has been introduced to get.
 しかしながら、上記した従来技術では、以下の理由から皮膜中のイミド塩由来成分を濃化することはできなかった。先ず、負極活物質として黒鉛を用いる場合、黒鉛を電荷担体に対して可逆的に反応させ、非水電解質二次電池を可逆的に充放電させるためには、負極の表面にSEI皮膜が形成されている必要があると考えられている。従来は、このSEI皮膜を形成するために、ECを代表とする環状カーボネート化合物を電解液用の有機溶媒として用いていた。そして、当該環状カーボネート化合物の分解物によりSEI皮膜を形成していた。つまり、イミド塩を含む従来の電解液は、有機溶媒としてEC等の環状カーボネートを多く含有するとともに、添加剤としてイミド塩を含んでいた。しかしこの場合、SEI皮膜の主成分は有機溶媒に由来する成分となり、SEI皮膜のイミド塩の含有量を増大させるのは困難であった。 However, in the above-described conventional technology, the imide salt-derived component in the film could not be concentrated for the following reasons. First, when graphite is used as the negative electrode active material, an SEI film is formed on the surface of the negative electrode in order to cause the graphite to react reversibly with the charge carrier and to reversibly charge and discharge the nonaqueous electrolyte secondary battery. It is considered necessary to be. Conventionally, in order to form this SEI film, a cyclic carbonate compound typified by EC has been used as an organic solvent for the electrolytic solution. And the SEI membrane | film | coat was formed with the decomposition product of the said cyclic carbonate compound. That is, the conventional electrolyte solution containing an imide salt contains a large amount of cyclic carbonate such as EC as an organic solvent and also contains an imide salt as an additive. However, in this case, the main component of the SEI film is a component derived from an organic solvent, and it is difficult to increase the content of the imide salt of the SEI film.
 また、イミド塩を添加剤としてではなく金属塩(つまり電解質塩、支持塩)として用いようとする場合、正極用の集電体との組み合わせを考慮する必要があった。つまり、イミド塩は、正極用の集電体として一般に用いられているアルミニウム集電体を腐食することが知られている。このため、特に4V程度の電位で作動する正極を用いる場合は、アルミニウムと不動体を形成するLiPF等を電解質塩とした電解液をアルミニウム集電体と共存させる必要がある。また従来の電解液ではLiPFやイミド塩等からなる電解質塩の合計濃度は、イオン伝導度や粘度の観点から、1mol/L~2mol/L程度が最適とされている(特開2013-145732)。したがってLiPFを充分な量添加すると、必然的にイミド塩の添加量は低減するため、イミド塩を電解液用の金属塩として多量に使用し難い問題があった。以下、必要に応じて、イミド塩を単に金属塩と略する場合がある。 Further, when an imide salt is used as a metal salt (that is, an electrolyte salt or a supporting salt) rather than as an additive, it is necessary to consider a combination with a current collector for a positive electrode. That is, imide salts are known to corrode aluminum current collectors that are generally used as current collectors for positive electrodes. For this reason, when using the positive electrode which operates at a potential of about 4 V in particular, it is necessary to coexist with an aluminum current collector an electrolytic solution containing LiPF 6 or the like that forms an immobile with aluminum as an electrolyte salt. In the conventional electrolytic solution, the total concentration of the electrolyte salt composed of LiPF 6 or imide salt is optimally about 1 mol / L to 2 mol / L from the viewpoint of ionic conductivity and viscosity (Japanese Patent Laid-Open No. 2013-145732). ). Therefore, when a sufficient amount of LiPF 6 is added, the amount of imide salt added is inevitably reduced, so that there is a problem that it is difficult to use a large amount of imide salt as a metal salt for an electrolytic solution. Hereinafter, if necessary, the imide salt may be simply abbreviated as a metal salt.
 これに対して、本発明の電解液は金属塩を高濃度で含む。そして後述するように、本発明の電解液中において、金属塩は従来とは全く異なる状態で存在していると考えられる。このため、本発明の電解液では、従来の電解液とは異なり、金属塩が高濃度であることに由来する問題は生じ難い。例えば、本発明の電解液によると、電解液の粘度上昇による非水電解質二次電池の入出力性能の低下を抑制できるし、アルミニウム集電体の腐食を抑制することも可能である。また、電解液に高濃度で含まれる金属塩は、負極上で優先的に還元分解される。その結果、有機溶媒としてEC等の環状カーボネート化合物を用いなくても、金属塩に由来する特殊構造のSEI皮膜、つまりS,O含有皮膜が負極上に形成される。このため本発明の非水電解質二次電池は、負極活物質として黒鉛を用いる場合にも、有機溶媒に環状カーボネート化合物を用いることなく可逆的に充放電可能である。 In contrast, the electrolytic solution of the present invention contains a metal salt at a high concentration. As will be described later, in the electrolytic solution of the present invention, it is considered that the metal salt is present in a state completely different from the conventional one. For this reason, in the electrolytic solution of the present invention, unlike the conventional electrolytic solution, a problem caused by the high concentration of the metal salt hardly occurs. For example, according to the electrolytic solution of the present invention, it is possible to suppress a decrease in input / output performance of the nonaqueous electrolyte secondary battery due to an increase in the viscosity of the electrolytic solution, and it is also possible to suppress corrosion of the aluminum current collector. Further, the metal salt contained in the electrolytic solution at a high concentration is preferentially reduced and decomposed on the negative electrode. As a result, an SEI film having a special structure derived from a metal salt, that is, an S, O-containing film is formed on the negative electrode without using a cyclic carbonate compound such as EC as the organic solvent. Therefore, the nonaqueous electrolyte secondary battery of the present invention can be reversibly charged and discharged without using a cyclic carbonate compound as an organic solvent even when graphite is used as the negative electrode active material.
 このため本発明の非水電解質二次電池は、負極活物質として黒鉛を用いかつ正極用集電体としてアルミニウム集電体を用いる場合においても、有機溶媒として環状カーボネート化合物を用いたり金属塩としてLiPFを用いたりすることなく、可逆的に充放電可能である。さらに、負極および/または正極表面のSEI皮膜の大部分をアニオン由来成分で構成することが可能となる。後述するように、アニオン由来成分を含むS,O含有皮膜によると非水電解質二次電池の電池特性を向上させ得る。 Therefore, the nonaqueous electrolyte secondary battery of the present invention uses a cyclic carbonate compound as the organic solvent or LiPF as the metal salt even when graphite is used as the negative electrode active material and an aluminum current collector is used as the positive electrode current collector. 6 can be reversibly charged / discharged. Furthermore, most of the SEI film on the negative electrode and / or positive electrode surface can be composed of anion-derived components. As will be described later, the S, O-containing film containing an anion-derived component can improve the battery characteristics of the nonaqueous electrolyte secondary battery.
 なお、EC溶媒を含む一般的な電解液を用いた非水電解質二次電池において負極の皮膜には、EC溶媒に由来する炭素が重合したポリマー構造が多く含まれる。これに対して、本発明の非水電解質二次電池における負極S,O含有皮膜には、このような炭素が重合したポリマー構造は殆ど(または全く)含まれず、金属塩のアニオンに由来する構造を多く含む。正極皮膜に関しても同様である。 Note that in the nonaqueous electrolyte secondary battery using a general electrolytic solution containing an EC solvent, the negative electrode film includes many polymer structures in which carbon derived from the EC solvent is polymerized. On the other hand, the negative electrode S, O-containing film in the nonaqueous electrolyte secondary battery of the present invention contains almost no (or no) polymer structure obtained by polymerizing such carbon, and is derived from an anion of a metal salt. Including many. The same applies to the positive electrode film.
 ところで、本発明の電解液は金属塩のカチオンを高濃度で含有する。このため、本発明の電解液中において、隣り合うカチオン間の距離は極めて近い。そして、非水電解質二次電池の充放電時にリチウムイオン等のカチオンが正極と負極との間を移動する際には、移動先の電極に直近のカチオンが先ず当該電極に供給される。そして、供給された当該カチオンがあった場所には、当該カチオンに隣り合う他のカチオンが移動する。つまり、本発明の電解液中においては、隣り合うカチオンが供給対象となる電極に向けて順番に一つずつ位置を変えるという、ドミノ倒し様の現象が生じていると予想される。このため、充放電時のカチオンの移動距離は短く、その分だけカチオンの移動速度が高いと考えられる。そして、このことに起因して、本発明の電解液を有する本発明の非水電解質二次電池の反応速度は高いと考えられる。また、本発明の非水電解質二次電池は電極(つまり負極および/または正極)にS,O含有皮膜を有し、当該S,O含有皮膜はS=O構造を有するとともに多くのカチオンを含むと考えられる。このS,O含有皮膜に含まれるカチオンは電極に優先的に供給されると考えられる。よって、本発明の非水電解質二次電池においては、電極近傍に豊富なカチオン源(つまりS,O含有皮膜)を有することによってもカチオンの輸送速度がさらに向上すると考えられる。したがって、本発明の非水電解質二次電池においては、本発明の電解液とS,O含有皮膜との協働によって、優れた電池特性が発揮されると考えられる。 Incidentally, the electrolytic solution of the present invention contains a metal salt cation in a high concentration. For this reason, in the electrolytic solution of the present invention, the distance between adjacent cations is extremely short. When cations such as lithium ions move between the positive electrode and the negative electrode during charge / discharge of the nonaqueous electrolyte secondary battery, the cations closest to the destination electrode are first supplied to the electrode. And the other cation adjacent to the said cation moves to the place with the said supplied cation. In other words, in the electrolytic solution of the present invention, it is expected that a domino-like phenomenon occurs in which adjacent cations change one by one toward the electrode to be supplied one by one. For this reason, the movement distance of the cation at the time of charging / discharging is short, and it is thought that the movement speed | rate of a cation is high by that much. Due to this, the reaction rate of the nonaqueous electrolyte secondary battery of the present invention having the electrolytic solution of the present invention is considered to be high. In addition, the nonaqueous electrolyte secondary battery of the present invention has an S, O-containing film on an electrode (that is, a negative electrode and / or a positive electrode), and the S, O-containing film has an S═O structure and contains many cations. it is conceivable that. It is considered that cations contained in the S, O-containing film are preferentially supplied to the electrode. Therefore, in the nonaqueous electrolyte secondary battery of the present invention, it is considered that the cation transport rate is further improved by having an abundant cation source (that is, an S, O-containing film) in the vicinity of the electrode. Therefore, in the nonaqueous electrolyte secondary battery of the present invention, it is considered that excellent battery characteristics are exhibited by the cooperation of the electrolytic solution of the present invention and the S, O-containing film.
 参考までに、負極のSEI皮膜は、所定以下の電圧で電解液が還元分解し、その際に生成した電解液の堆積物によって構成されると考えられている。つまり、負極の表面に上述したS,O含有皮膜を効率良く生成させるためには、本発明の非水電解質二次電池は、負極の電位の最小値が所定以下になるようにするのが良い。具体的には、本発明の非水電解質二次電池は、対極をリチウムにした場合に負極の電位の最小値が1.3V以下となる条件で使用する電池として好適である。 For reference, it is considered that the SEI film of the negative electrode is constituted by a deposit of the electrolytic solution generated by reductive decomposition of the electrolytic solution at a predetermined voltage or less. That is, in order to efficiently generate the above-described S, O-containing film on the surface of the negative electrode, the non-aqueous electrolyte secondary battery of the present invention should have the minimum value of the negative electrode potential not more than a predetermined value. . Specifically, the nonaqueous electrolyte secondary battery of the present invention is suitable as a battery to be used under the condition that the minimum value of the negative electrode potential is 1.3 V or less when the counter electrode is lithium.
 本発明の非水電解質二次電池における負極は、特に限定されない。負極活物質としては、電荷担体を吸蔵および放出し得る一般的なものを使用可能である。例えば、非水電解質二次電池がリチウムイオン二次電池である場合には、負極活物質として、リチウムイオンを吸蔵および放出し得る材料を選択すれば良い。より詳しくは、Li等の電荷担体と合金化可能な元素(単体)、当該元素を含む合金、または当該元素を含む化合物であれば良い。具体的には、負極活物質として、Liや、炭素、ケイ素、ゲルマニウム、錫などの14族元素、アルミニウム、インジウムなどの13族元素、亜鉛、カドミウムなどの12族元素、アンチモン、ビスマスなどの15族元素、マグネシウム、カルシウムなどのアルカリ土類金属、銀、金などの11族元素をそれぞれ単体で採用すればよい。ケイ素などを負極活物質に採用すると、ケイ素1原子が複数のリチウムと反応するため、高容量の活物質となるが、リチウムの吸蔵および放出に伴う体積の膨張および収縮が顕著となるとの問題が生じる恐れがあるため、当該恐れの軽減のために、ケイ素などの単体に遷移金属などの他の元素を組み合わせた合金または化合物を負極活物質として採用するのも好適である。合金または化合物の具体例としては、Ag-Sn合金、Cu-Sn合金、Co-Sn合金等の錫系材料、各種黒鉛などの炭素系材料、ケイ素単体と二酸化ケイ素に不均化するSiO(0.3≦x≦1.6)などのケイ素系材料、ケイ素単体若しくはケイ素系材料と炭素系材料を組み合わせた複合体が挙げられる。また、負極活物質として、Nb、TiO、LiTi12、WO、MoO、Fe等の酸化物、または、Li3-xN(M=Co、Ni、Cu)で表される窒化物を採用しても良い。負極活物質として、これらのものの一種以上を使用することができる。 The negative electrode in the nonaqueous electrolyte secondary battery of the present invention is not particularly limited. As the negative electrode active material, a general material that can occlude and release charge carriers can be used. For example, when the non-aqueous electrolyte secondary battery is a lithium ion secondary battery, a material capable of inserting and extracting lithium ions may be selected as the negative electrode active material. More specifically, an element (single element) that can be alloyed with a charge carrier such as Li, an alloy containing the element, or a compound containing the element may be used. Specifically, as the negative electrode active material, a group 14 element such as Li, carbon, silicon, germanium or tin, a group 13 element such as aluminum or indium, a group 12 element such as zinc or cadmium, 15 such as antimony or bismuth, etc. A group element, an alkaline earth metal such as magnesium and calcium, and a group 11 element such as silver and gold may be employed alone. When silicon or the like is used for the negative electrode active material, since one silicon atom reacts with a plurality of lithiums, it becomes a high-capacity active material, but there is a problem that the expansion and contraction of the volume accompanying the insertion and extraction of lithium becomes significant. In order to reduce the fear, it is also preferable to employ an alloy or a compound in which another element such as a transition metal is combined with a simple substance such as silicon as the negative electrode active material. Specific examples of the alloy or compound include tin-based materials such as Ag—Sn alloy, Cu—Sn alloy and Co—Sn alloy, carbon-based materials such as various graphites, SiO x (disproportionated to silicon simple substance and silicon dioxide). Examples thereof include silicon-based materials such as 0.3 ≦ x ≦ 1.6), silicon alone, or composites obtained by combining silicon-based materials and carbon-based materials. Further, as the negative electrode active material, oxides such as Nb 2 O 5 , TiO 2 , Li 4 Ti 5 O 12 , WO 2 , MoO 2 , Fe 2 O 3 , or Li 3-x M x N (M = Co Nitride represented by Ni, Cu) may be employed. One or more of these materials can be used as the negative electrode active material.
 上述したように、本発明の非水電解質二次電池(1)は負極表面にS,O含有皮膜が形成されたものである。したがって、低電位負極に対応可能である。具体的には非水電解質二次電池(1)は、負極活物質として、黒鉛等の炭素元素を含有するものや、Si系の負極活物質を選択し得る。黒鉛は、天然、人造を問わず、その粒径もまた特に限定しない。 As described above, the non-aqueous electrolyte secondary battery (1) of the present invention has an S, O-containing film formed on the negative electrode surface. Therefore, it can respond to a low potential negative electrode. Specifically, in the nonaqueous electrolyte secondary battery (1), a material containing a carbon element such as graphite or a Si-based negative electrode active material can be selected as the negative electrode active material. The particle diameter of graphite is not particularly limited, whether natural or artificial.
 本発明の非水電解質二次電池は、リチウムイオン等の電荷担体を吸蔵および放出し得る負極活物質を有する負極と、当該電荷担体を吸蔵および放出し得る正極活物質を有する正極と、上述した本発明の電解液を備える。例えば、本発明の非水電解質二次電池がリチウムイオン二次電池である場合には、負極活物質はリチウムイオンを吸蔵および放出し得るものであり、正極活物質はリチウムイオンを吸蔵および放出し得るものであり、電解液は金属塩としてリチウム塩を採用したものである。 The non-aqueous electrolyte secondary battery of the present invention includes a negative electrode having a negative electrode active material capable of occluding and releasing charge carriers such as lithium ions, a positive electrode having a positive electrode active material capable of occluding and releasing the charge carriers, and The electrolytic solution of the present invention is provided. For example, when the non-aqueous electrolyte secondary battery of the present invention is a lithium ion secondary battery, the negative electrode active material can occlude and release lithium ions, and the positive electrode active material can occlude and release lithium ions. The electrolytic solution employs a lithium salt as a metal salt.
 負極は、集電体と、集電体の表面に結着させた負極活物質層を有する。負極活物質に関しては既述した。 The negative electrode has a current collector and a negative electrode active material layer bound to the surface of the current collector. The negative electrode active material has already been described.
 集電体は、非水電解質二次電池の放電または充電の間、電極に電流を流し続けるための化学的に不活性な電子高伝導体をいう。負極用の集電体としては、銀、銅、金、アルミニウム、タングステン、コバルト、亜鉛、ニッケル、鉄、白金、錫、インジウム、チタン、ルテニウム、タンタル、クロム、モリブデンから選ばれる少なくとも一種、ならびにステンレス鋼などの金属材料を例示することができる。集電体は公知の保護層で被覆されていても良い。集電体の表面を公知の方法で処理したものを集電体として用いても良い。 The current collector is a chemically inert electronic high conductor that keeps a current flowing through an electrode during discharge or charging of a nonaqueous electrolyte secondary battery. As the current collector for the negative electrode, at least one selected from silver, copper, gold, aluminum, tungsten, cobalt, zinc, nickel, iron, platinum, tin, indium, titanium, ruthenium, tantalum, chromium, molybdenum, and stainless steel A metal material such as steel can be exemplified. The current collector may be covered with a known protective layer. What collected the surface of the electrical power collector by the well-known method may be used as an electrical power collector.
 集電体は箔、シート、フィルム、線状、棒状、メッシュなどの形態をとることができる。そのため、集電体として、例えば、銅箔、ニッケル箔、アルミニウム箔、ステンレス箔などの金属箔を好適に用いることができる。集電体が箔、シート、フィルム形態の場合は、その厚みが1μm~100μmの範囲内であることが好ましい。 The current collector can take the form of a foil, a sheet, a film, a linear shape, a rod shape, a mesh, or the like. Therefore, for example, a metal foil such as a copper foil, a nickel foil, an aluminum foil, and a stainless steel foil can be suitably used as the current collector. When the current collector is in the form of foil, sheet or film, the thickness is preferably in the range of 1 μm to 100 μm.
 負極活物質層は負極活物質、ならびに必要に応じて結着剤および/または導電助剤を含む。非水電解質二次電池(2)は、特定の結着剤を用いたものである。 The negative electrode active material layer includes a negative electrode active material and, if necessary, a binder and / or a conductive aid. The non-aqueous electrolyte secondary battery (2) uses a specific binder.
 結着剤は、負極活物質粒子どうし、あるいは負極活物質および導電助剤を集電体の表面に繋ぎ止める役割を果たすものである。非水電解質二次電池(2)は、結着剤に親水基を有するポリマーを含んでいる。親水基を有するポリマーの親水基としては、カルボキシル基、スルホ基、シラノール基、アミノ基、水酸基、アミノ基、リン酸基などリン酸系の基などが例示される。中でも、ポリアクリル酸(PAA)、カルボキシメチルセルロース(CMC)、ポリメタクリル酸など、分子中にカルボキシル基を含むポリマー、またはポリ(P-スチレンスルホン酸)などのスルホ基を含むポリマーが好ましい。 The binder serves to bind the negative electrode active material particles or the negative electrode active material and the conductive auxiliary agent to the surface of the current collector. The nonaqueous electrolyte secondary battery (2) contains a polymer having a hydrophilic group in the binder. Examples of the hydrophilic group of the polymer having a hydrophilic group include a phosphate group such as a carboxyl group, a sulfo group, a silanol group, an amino group, a hydroxyl group, an amino group, and a phosphate group. Among them, a polymer containing a carboxyl group in the molecule such as polyacrylic acid (PAA), carboxymethyl cellulose (CMC), or polymethacrylic acid, or a polymer containing a sulfo group such as poly (P-styrenesulfonic acid) is preferable.
 ポリアクリル酸、あるいはアクリル酸とビニルスルホン酸との共重合体など、カルボキシル基および/またはスルホ基を多く含むポリマーは水溶性となる。したがって親水基を有するポリマーは、水溶性ポリマーであることが好ましく、一分子中に複数のカルボキシル基および/またはスルホ基を含むポリマーが好ましい。 Polymers containing a large amount of carboxyl groups and / or sulfo groups, such as polyacrylic acid or a copolymer of acrylic acid and vinyl sulfonic acid, are water-soluble. Therefore, the polymer having a hydrophilic group is preferably a water-soluble polymer, and a polymer containing a plurality of carboxyl groups and / or sulfo groups in one molecule is preferable.
 分子中にカルボキシル基を含むポリマーは、例えば、ポリアクリル酸など酸モノマーを重合する方法、あるいはカルボキシメチルセルロース(CMC)などポリマーにカルボキシル基を付与する方法、などの方法で製造することができる。酸モノマーとしては、アクリル酸、メタクリル酸、ビニル安息香酸、クロトン酸、ペンテン酸、アンジェリカ酸、チグリン酸など分子中に一つのカルボキシル基をもつ酸モノマー、イタコン酸、メサコン酸、シトラコン酸、フマル酸、マレイン酸、2-ペンテン二酸、メチレンコハク酸、アリルマロン酸、イソプロピリデンコハク酸、2,4-ヘキサジエン二酸、アセチレンジカルボン酸など分子内に二つ以上のカルボキシル基をもつ酸モノマーなどが例示される。これらから選ばれる二種以上のモノマーを重合してなる共重合ポリマーを用いてもよい。 The polymer containing a carboxyl group in the molecule can be produced by, for example, a method of polymerizing an acid monomer such as polyacrylic acid or a method of imparting a carboxyl group to a polymer such as carboxymethyl cellulose (CMC). Acid monomers include acrylic acid, methacrylic acid, vinyl benzoic acid, crotonic acid, pentenoic acid, angelic acid, tiglic acid, etc., acid monomers having one carboxyl group in the molecule, itaconic acid, mesaconic acid, citraconic acid, fumaric acid Examples include maleic acid, 2-pentenedioic acid, methylene succinic acid, allyl malonic acid, isopropylidene succinic acid, 2,4-hexadiene diacid, acetylenedicarboxylic acid, and other acid monomers having two or more carboxyl groups in the molecule. Is done. A copolymer obtained by polymerizing two or more kinds of monomers selected from these may be used.
 例えば特開2013-065493号公報に記載されたような、アクリル酸とイタコン酸との共重合体からなり、カルボキシル基どうしが縮合して形成された酸無水物基を分子中に含んでいるポリマーを結着剤として用いることも好ましい。一分子中にカルボキシル基を二つ以上有する酸性度の高いモノマー由来の構造があることにより、充電時に電解液分解反応が起こる前にリチウムイオンなどをトラップし易くなると考えられている。さらに、ポリアクリル酸やポリメタクリル酸に比べてカルボキシル基が多く酸性度が高まると共に、所定量のカルボキシル基が酸無水物基に変化しているため、酸性度が高まりすぎることもない。そのため、この負極用結着剤を用いて形成された負極をもつ二次電池は、初期効率が向上し、入出力特性が向上する。 For example, a polymer composed of a copolymer of acrylic acid and itaconic acid as described in JP2013-065493A, and containing an acid anhydride group formed by condensation of carboxyl groups in the molecule It is also preferable to use as a binder. The structure derived from a highly acidic monomer having two or more carboxyl groups in one molecule is considered to facilitate trapping of lithium ions and the like before the electrolytic solution decomposition reaction occurs during charging. Furthermore, the acidity is not excessively increased because there are more carboxyl groups and the acidity is higher than polyacrylic acid and polymethacrylic acid, and a predetermined amount of the carboxyl groups are changed to acid anhydride groups. Therefore, a secondary battery having a negative electrode formed using this negative electrode binder has improved initial efficiency and improved input / output characteristics.
 また性能を損なわない範囲内で、ポリフッ化ビニリデン、ポリテトラフルオロエチレン、フッ素ゴム等の含フッ素樹脂、ポリプロピレン、ポリエチレン等の熱可塑性樹脂、ポリイミド、ポリアミドイミド等のイミド系樹脂、アルコキシシリル基含有樹脂などのポリマーを混合してもよい。 In addition, within the range that does not impair the performance, fluorine-containing resins such as polyvinylidene fluoride, polytetrafluoroethylene, and fluororubber, thermoplastic resins such as polypropylene and polyethylene, imide resins such as polyimide and polyamideimide, and alkoxysilyl group-containing resins A polymer such as
 負極活物質層中の結着剤の配合割合は、質量比で、負極活物質:結着剤=1:0.005~1:0.3であるのが好ましい。結着剤が少なすぎると電極の成形性が低下し、また、結着剤が多すぎると電極のエネルギー密度が低くなるためである。 The blending ratio of the binder in the negative electrode active material layer is preferably a negative electrode active material: binder = 1: 0.005 to 1: 0.3 in mass ratio. This is because when the amount of the binder is too small, the moldability of the electrode is lowered, and when the amount of the binder is too large, the energy density of the electrode is lowered.
 非水電解質二次電池(1)の結着剤は、上記の結着剤であっても良いしその他の結着剤であっても良い。例えば、結着剤として、ポリフッ化ビニリデン、ポリテトラフルオロエチレン、フッ素ゴム等の含フッ素樹脂、ポリプロピレン、ポリエチレン等の熱可塑性樹脂、ポリイミド、ポリアミドイミド等のイミド系樹脂、アルコキシシリル基含有樹脂を例示することができる。 The binder of the non-aqueous electrolyte secondary battery (1) may be the above-mentioned binder or other binders. Examples of binders include fluorine-containing resins such as polyvinylidene fluoride, polytetrafluoroethylene, and fluororubber, thermoplastic resins such as polypropylene and polyethylene, imide resins such as polyimide and polyamideimide, and alkoxysilyl group-containing resins. can do.
 何れの場合にも、負極活物質層中の結着剤の配合割合は、質量比で、負極活物質:結着剤=1:0.005~1:0.3であるのが好ましい。結着剤が少なすぎると電極の成形性が低下し、また、結着剤が多すぎると電極のエネルギー密度が低くなるためである。 In any case, the mixing ratio of the binder in the negative electrode active material layer is preferably negative electrode active material: binder = 1: 0.005 to 1: 0.3 in terms of mass ratio. This is because when the amount of the binder is too small, the moldability of the electrode is lowered, and when the amount of the binder is too large, the energy density of the electrode is lowered.
 導電助剤は、電極の導電性を高めるために添加される。そのため、導電助剤は、電極の導電性が不足する場合に任意に加えればよく、電極の導電性が十分に優れている場合には加えなくても良い。導電助剤としては化学的に不活性な電子高伝導体であれば良く、炭素質微粒子であるカーボンブラック、黒鉛、アセチレンブラック、ケッチェンブラック(登録商標)、気相法炭素繊維(Vapor Grown Carbon Fiber:VGCF)、および各種金属粒子などが例示される。これらの導電助剤を単独または二種以上組み合わせて活物質層に添加することができる。負極活物質層中の導電助剤の配合割合は、質量比で、負極活物質:導電助剤=1:0.01~1:0.5であるのが好ましい。導電助剤が少なすぎると効率のよい導電パスを形成できず、また、導電助剤が多すぎると負極活物質層の成形性が悪くなるとともに電極のエネルギー密度が低くなるためである。 Conductive aid is added to increase the conductivity of the electrode. Therefore, the conductive auxiliary agent may be added arbitrarily when the electrode conductivity is insufficient, and may not be added when the electrode conductivity is sufficiently excellent. The conductive auxiliary agent may be any chemically inert electronic high conductor, such as carbon black, graphite, acetylene black, ketjen black (registered trademark), vapor grown carbon fiber (Vapor Growth Carbon, carbonaceous fine particles). Fiber: VGCF) and various metal particles are exemplified. These conductive assistants can be added to the active material layer alone or in combination of two or more. The blending ratio of the conductive assistant in the negative electrode active material layer is preferably negative electrode active material: conductive assistant = 1: 0.01 to 1: 0.5 in terms of mass ratio. This is because if the amount of the conductive aid is too small, an efficient conductive path cannot be formed, and if the amount of the conductive aid is too large, the formability of the negative electrode active material layer is deteriorated and the energy density of the electrode is lowered.
 上記結着剤を用いて、非水電解質二次電池の負極を作製するには、負極活物質粉末と、炭素粉末などの導電助剤と、上記結着剤と、適量の溶剤を加えて混合しスラリーにしたものを、ロールコート法、ディップコート法、ドクターブレード法、スプレーコート法、カーテンコート法などの方法で集電体上に塗布し、上記結着剤を乾燥あるいは硬化させることによって作製することができる。溶剤としては、N-メチル-2-ピロリドン、メタノール、メチルイソブチルケトン、水を例示できる。電極密度を高めるべく、乾燥後のものを圧縮しても良い。 In order to produce a negative electrode of a non-aqueous electrolyte secondary battery using the binder, a negative electrode active material powder, a conductive aid such as carbon powder, the binder, and an appropriate amount of solvent are added and mixed. The slurry is applied to the current collector by a roll coating method, dip coating method, doctor blade method, spray coating method, curtain coating method, etc., and the binder is produced by drying or curing. can do. Examples of the solvent include N-methyl-2-pyrrolidone, methanol, methyl isobutyl ketone, and water. In order to increase the electrode density, the dried product may be compressed.
 〔正極〕
 非水電解質二次電池に用いられる正極は、リチウムイオン等の電荷担体を吸蔵および放出し得る正極活物質を有する。正極は、集電体と、集電体の表面に結着させた正極活物質層を有する。正極活物質層は正極活物質、ならびに必要に応じて結着剤および/または導電助剤を含む。正極の集電体は、使用する活物質に適した電圧に耐え得る金属であれば特に制限はなく、例えば、銀、銅、金、アルミニウム、タングステン、コバルト、亜鉛、ニッケル、鉄、白金、錫、インジウム、チタン、ルテニウム、タンタル、クロム、モリブデンから選ばれる少なくとも一種、ならびにステンレス鋼などの金属材料を例示することができる。
[Positive electrode]
A positive electrode used for a non-aqueous electrolyte secondary battery has a positive electrode active material that can occlude and release charge carriers such as lithium ions. The positive electrode has a current collector and a positive electrode active material layer bound to the surface of the current collector. The positive electrode active material layer includes a positive electrode active material and, if necessary, a binder and / or a conductive aid. The positive electrode current collector is not particularly limited as long as it is a metal that can withstand a voltage suitable for the active material to be used. For example, silver, copper, gold, aluminum, tungsten, cobalt, zinc, nickel, iron, platinum, tin , Indium, titanium, ruthenium, tantalum, chromium, molybdenum, and metal materials such as stainless steel.
 正極の電位をリチウム基準で4V以上とする場合には、集電体としてアルミニウムを採用するのが好ましい。 When the potential of the positive electrode is 4 V or higher with respect to lithium, it is preferable to employ aluminum as the current collector.
 具体的には、正極用集電体として、アルミニウムまたはアルミニウム合金からなるものを用いるのが好ましい。ここでアルミニウムは、純アルミニウムを指し、純度99.0%以上のアルミニウムを純アルミニウムと称する。純アルミニウムに種々の元素を添加して合金としたものをアルミニウム合金と称する。アルミニウム合金としては、Al-Cu系、Al-Mn系、Al-Fe系、Al-Si系、Al-Mg系、AL-Mg-Si系、Al-Zn-Mg系が挙げられる。 Specifically, the positive electrode current collector is preferably made of aluminum or an aluminum alloy. Here, aluminum refers to pure aluminum, and aluminum having a purity of 99.0% or more is referred to as pure aluminum. An alloy obtained by adding various elements to pure aluminum is referred to as an aluminum alloy. Examples of the aluminum alloy include Al—Cu, Al—Mn, Al—Fe, Al—Si, Al—Mg, AL—Mg—Si, and Al—Zn—Mg.
 また、アルミニウムまたはアルミニウム合金として、具体的には、例えばJIS A1085、A1N30等のA1000系合金(純アルミニウム系)、JIS A3003、A3004等のA3000系合金(Al-Mn系)、JIS A8079、A8021等のA8000系合金(Al-Fe系)が挙げられる。集電体は公知の保護層で被覆されていても良い。集電体の表面を公知の方法で処理したものを集電体として用いても良い。 Specific examples of aluminum or aluminum alloy include, for example, A1000 series alloys (pure aluminum series) such as JIS A1085 and A1N30, A3000 series alloys (Al-Mn series) such as JIS A3003 and A3004, JIS A8079, A8021, etc. A8000-based alloy (Al-Fe-based). The current collector may be covered with a known protective layer. What collected the surface of the electrical power collector by the well-known method may be used as an electrical power collector.
 集電体は箔、シート、フィルム、線状、棒状、メッシュなどの形態をとることができる。そのため、集電体として、例えば、銅箔、ニッケル箔、アルミニウム箔、ステンレス箔などの金属箔を好適に用いることができる。集電体が箔、シート、フィルム形態の場合は、その厚みが1μm~100μmの範囲内であることが好ましい。これは、上述した負極用の集電体に関しても同様である。 The current collector can take the form of a foil, a sheet, a film, a linear shape, a rod shape, a mesh, or the like. Therefore, for example, a metal foil such as a copper foil, a nickel foil, an aluminum foil, and a stainless steel foil can be suitably used as the current collector. When the current collector is in the form of foil, sheet or film, the thickness is preferably in the range of 1 μm to 100 μm. The same applies to the negative electrode current collector described above.
 正極の結着剤および導電助剤は負極で説明したものと同様である。 The binder for the positive electrode and the conductive additive are the same as those described for the negative electrode.
 正極活物質としては、層状化合物のLiNiCoMn(0.2≦a≦1.2、b+c+d+e=1、0≦e<1、DはLi、Fe、Cr、Cu、Zn、Ca、Mg、S、Si、Na、K、Al、Zr、Ti、P、Ga、Ge、V、Mo、Nb、W、Laから選ばれる少なくとも1の元素、1.7≦f≦2.1)、LiMnOを挙げることができる。また、正極活物質として、LiMn等のスピネル、およびスピネルと層状化合物の混合物で構成される固溶体、LiMPO、LiMVOまたはLiMSiO(式中のMはCo、Ni、Mn、Feのうちの少なくとも一種から選択される)などで表されるポリアニオン系化合物を挙げることができる。さらに、正極活物質として、LiFePOFなどのLiMPOF(Mは遷移金属)で表されるタボライト系化合物、LiFeBOなどのLiMBO(Mは遷移金属)で表されるボレート系化合物を挙げることができる。正極活物質として用いられるいずれの金属酸化物も上記の組成式を基本組成とすればよく、基本組成に含まれる金属元素を他の金属元素で置換したものも使用可能である。また、正極活物質として、電荷担体(例えば充放電に寄与するリチウムイオン)を含まないものを用いても良い。例えば、硫黄単体(S)、硫黄と炭素を複合化した化合物、TiSなどの金属硫化物、V、MnOなどの酸化物、ポリアニリンおよびアントラキノンならびにこれら芳香族を化学構造に含む化合物、共役二酢酸系有機物などの共役系材料、その他公知の材料を用いることもできる。さらに、ニトロキシド、ニトロニルニトロキシド、ガルビノキシル、フェノキシルなどの安定なラジカルを有する化合物を正極活物質として採用してもよい。 As the positive electrode active material, the layered compound Li a Ni b Co c Mn d De O f (0.2 ≦ a ≦ 1.2, b + c + d + e = 1, 0 ≦ e <1, D is Li, Fe, Cr, At least one element selected from Cu, Zn, Ca, Mg, S, Si, Na, K, Al, Zr, Ti, P, Ga, Ge, V, Mo, Nb, W, La, 1.7 ≦ f ≦ 2.1) and Li 2 MnO 3 . Further, as a positive electrode active material, a solid solution composed of a spinel such as LiMn 2 O 4 and a mixture of a spinel and a layered compound, LiMPO 4 , LiMVO 4 or Li 2 MSiO 4 (wherein M is Co, Ni, Mn, And a polyanionic compound represented by (selected from at least one of Fe). Furthermore, as the positive electrode active material, tavorite compound (the M a transition metal) LiMPO 4 F, such as LiFePO 4 F represented by, Limbo 3 such LiFeBO 3 (M is a transition metal) include borate-based compound represented by be able to. Any metal oxide used as the positive electrode active material may have the above composition formula as a basic composition, and a metal element contained in the basic composition may be substituted with another metal element. Moreover, you may use as a positive electrode active material the thing which does not contain a charge carrier (for example, lithium ion which contributes to charging / discharging). For example, sulfur alone (S), a compound in which sulfur and carbon are compounded, a metal sulfide such as TiS 2 , an oxide such as V 2 O 5 and MnO 2 , a compound containing polyaniline and anthraquinone, and these aromatics in the chemical structure In addition, conjugated materials such as conjugated diacetate-based organic substances and other known materials can also be used. Further, a compound having a stable radical such as nitroxide, nitronyl nitroxide, galvinoxyl, phenoxyl, etc. may be adopted as the positive electrode active material.
 リチウム等の電荷担体を含まない正極活物質材料を用いる場合には、正極および/または負極に、公知の方法により、予め電荷担体を添加しておく必要がある。電荷担体は、イオンの状態で添加しても良いし、金属等の非イオンの状態で添加しても良い。例えば、電荷担体がリチウムである場合には、リチウム箔を正極および/または負極に貼り付けるなどして一体化しても良い。正極は、負極と同様に、導電助剤および結着剤等を含有しても良い。導電助剤および結着剤は特に限定されず、上記した負極同様に、非水電解質二次電池に使用可能なものであれば良い。 When using a positive electrode active material that does not contain a charge carrier such as lithium, it is necessary to add a charge carrier to the positive electrode and / or the negative electrode in advance by a known method. The charge carrier may be added in an ionic state or in a non-ionic state such as a metal. For example, when the charge carrier is lithium, it may be integrated by attaching a lithium foil to the positive electrode and / or the negative electrode. The positive electrode may contain a conductive additive, a binder, and the like, similarly to the negative electrode. The conductive aid and the binder are not particularly limited as long as they can be used for the nonaqueous electrolyte secondary battery as in the case of the negative electrode described above.
 集電体の表面に活物質層を形成させるには、ロールコート法、ダイコート法、ディップコート法、ドクターブレード法、スプレーコート法、カーテンコート法などの従来から公知の方法を用いて、集電体の表面に活物質を塗布すればよい。具体的には、活物質、ならびに必要に応じて結着剤および導電助剤を含む活物質層形成用組成物(所謂負極合材、正極合材)を調製し、この組成物に適当な溶剤を加えてペースト状にしてから、集電体の表面に塗布後、乾燥する。溶剤としては、N-メチル-2-ピロリドン、メタノール、メチルイソブチルケトン、水を例示できる。電極密度を高めるべく、乾燥後のものを圧縮しても良い。 In order to form an active material layer on the surface of the current collector, a current collecting method such as a roll coating method, a die coating method, a dip coating method, a doctor blade method, a spray coating method, or a curtain coating method can be used. An active material may be applied to the surface of the body. Specifically, an active material layer-forming composition (so-called negative electrode mixture, positive electrode mixture) containing an active material and, if necessary, a binder and a conductive additive is prepared, and a suitable solvent for this composition Is applied to the surface of the current collector and then dried. Examples of the solvent include N-methyl-2-pyrrolidone, methanol, methyl isobutyl ketone, and water. In order to increase the electrode density, the dried product may be compressed.
 非水電解質二次電池には必要に応じてセパレータが用いられる。セパレータは、正極と負極とを隔離し、両極の接触による電流の短絡を防止しつつ、リチウムイオンを通過させるものである。セパレータとしては、ポリテトラフルオロエチレン、ポリプロピレン、ポリエチレン、ポリイミド、ポリアミド、ポリアラミド(Aromatic polyamide)、ポリエステル、ポリアクリロニトリル等の合成樹脂、セルロース、アミロース等の多糖類、フィブロイン、ケラチン、リグニン、スベリン等の天然高分子、セラミックスなどの電気絶縁性材料を1種若しくは複数用いた多孔体、不織布、織布などを挙げることができる。また、セパレータは多層構造としてもよい。本発明の電解液は粘度がやや高く極性が高いため、水などの極性溶媒が浸み込みやすい膜が好ましい。具体的には、存在する空隙の90%以上に水などの極性溶媒が浸み込む膜がさらに好ましい。 A separator is used for non-aqueous electrolyte secondary batteries as necessary. The separator separates the positive electrode and the negative electrode and allows lithium ions to pass while preventing a short circuit of current due to contact between the two electrodes. As separators, natural resins such as polytetrafluoroethylene, polypropylene, polyethylene, polyimide, polyamide, polyaramid (Aromatic polymer), polyester, polyacrylonitrile, etc., polysaccharides such as cellulose, amylose, fibroin, keratin, lignin, suberin, etc. Examples thereof include porous bodies, nonwoven fabrics, and woven fabrics using one or more electrically insulating materials such as polymers and ceramics. The separator may have a multilayer structure. Since the electrolytic solution of the present invention has a slightly high viscosity and a high polarity, a membrane in which a polar solvent such as water can easily penetrate is preferable. Specifically, a film in which a polar solvent such as water soaks into 90% or more of the existing voids is more preferable.
 正極および負極に必要に応じてセパレータを挟装させ電極体とする。電極体は、正極、セパレータおよび負極を重ねた積層型、または、正極、セパレータおよび負極を捲いた捲回型のいずれの型にしても良い。正極の集電体および負極の集電体から外部に通ずる正極端子および負極端子までの間を、集電用リード等を用いて接続した後に、電極体に本発明の電解液を加えて非水電解質二次電池とするとよい。また、本発明の非水電解質二次電池は、電極に含まれる活物質の種類に適した電圧範囲で充放電を実行されればよい。 A separator is sandwiched between the positive electrode and the negative electrode as necessary to form an electrode body. The electrode body may be either a stacked type in which the positive electrode, the separator and the negative electrode are stacked, or a wound type in which the positive electrode, the separator and the negative electrode are sandwiched. After connecting between the positive electrode current collector and the negative electrode current collector to the positive electrode terminal and the negative electrode terminal that communicate with the outside using a current collecting lead, the electrolyte solution of the present invention is added to the electrode body to make a non-aqueous solution. It is preferable to use an electrolyte secondary battery. Moreover, the non-aqueous electrolyte secondary battery of this invention should just be charged / discharged in the voltage range suitable for the kind of active material contained in an electrode.
 本発明の非水電解質二次電池の形状は特に限定されるものでなく、円筒型、角型、コイン型、ラミネート型等、種々の形状を採用することができる。 The shape of the nonaqueous electrolyte secondary battery of the present invention is not particularly limited, and various shapes such as a cylindrical shape, a square shape, a coin shape, and a laminate shape can be adopted.
 本発明の非水電解質二次電池は、上述したように、電荷担体の種類を問わない。したがって、本発明の非水電解質二次電池は例えばリチウムイオン二次電池であっても良いし、リチウム二次電池であっても良い。或いは、リチウム以外の電荷担体(例えばナトリウム)を用いたものであっても良い。本発明の非水電解質二次電池は、車両に搭載してもよい。車両は、その動力源の全部あるいは一部に非水電解質二次電池による電気エネルギーを使用している車両であればよく、たとえば、電気車両、ハイブリッド車両などであるとよい。車両に非水電解質二次電池を搭載する場合には、非水電解質二次電池を複数直列に接続して組電池とするとよい。非水電解質二次電池を搭載する機器としては、車両以外にも、パーソナルコンピュータ、携帯通信機器など、電池で駆動される各種の家電製品、オフィス機器、産業機器などが挙げられる。さらに、本発明の非水電解質二次電池は、風力発電、太陽光発電、水力発電その他電力系統の蓄電装置および電力平滑化装置、船舶等の動力および/または補機類の電力供給源、航空機、宇宙船等の動力および/または補機類の電力供給源、電気を動力源に用いない車両の補助用電源、移動式の家庭用ロボットの電源、システムバックアップ用電源、無停電電源装置の電源、電動車両用充電ステーションなどにおいて充電に必要な電力を一時蓄える蓄電装置に用いてもよい。 As described above, the non-aqueous electrolyte secondary battery of the present invention may be of any type of charge carrier. Therefore, the nonaqueous electrolyte secondary battery of the present invention may be, for example, a lithium ion secondary battery or a lithium secondary battery. Alternatively, a charge carrier other than lithium (for example, sodium) may be used. The nonaqueous electrolyte secondary battery of the present invention may be mounted on a vehicle. The vehicle may be a vehicle that uses electric energy from the nonaqueous electrolyte secondary battery for all or a part of its power source, and may be, for example, an electric vehicle or a hybrid vehicle. When a non-aqueous electrolyte secondary battery is mounted on a vehicle, a plurality of non-aqueous electrolyte secondary batteries may be connected in series to form an assembled battery. In addition to vehicles, devices equipped with non-aqueous electrolyte secondary batteries include personal computers, portable communication devices, and various household electrical appliances driven by batteries, office equipment, industrial equipment, and the like. Further, the non-aqueous electrolyte secondary battery of the present invention includes wind power generation, solar power generation, hydroelectric power generation and other power system power storage devices and power smoothing devices, power for power sources such as ships, and / or power supply sources for auxiliary machinery, aircraft Power supplies for spacecrafts and / or auxiliary equipment, auxiliary power sources for vehicles that do not use electricity as power sources, mobile home robot power sources, system backup power sources, uninterruptible power supply power sources In addition, it may be used for a power storage device that temporarily stores electric power required for charging at an electric vehicle charging station or the like.
 以上、本発明の電解液の実施形態を説明したが、本発明は、上記実施形態に限定されるものではない。本発明の要旨を逸脱しない範囲において、当業者が行い得る変更、改良等を施した種々の形態にて実施することができる。 As mentioned above, although embodiment of the electrolyte solution of this invention was described, this invention is not limited to the said embodiment. The present invention can be implemented in various forms without departing from the gist of the present invention, with modifications and improvements that can be made by those skilled in the art.
 以下に、実施例および比較例を示し、本発明を具体的に説明する。なお、本発明は、これらの実施例によって限定されるものではない。以下において、特に断らない限り、「部」とは質量部を意味し、「%」とは質量%を意味する。 Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. In addition, this invention is not limited by these Examples. In the following, unless otherwise specified, “part” means part by mass, and “%” means mass%.
 〔電解液〕
 (E1)
 本発明の電解液を以下のとおり製造した。
[Electrolyte]
(E1)
The electrolytic solution of the present invention was produced as follows.
 有機溶媒である1,2-ジメトキシエタン約5mLを、撹拌子および温度計を備えたフラスコに入れた。撹拌条件下にて、上記フラスコ中の1,2-ジメトキシエタンに対し、リチウム塩である(CFSONLiを溶液温度が40℃以下を保つように徐々に加え、溶解させた。約13gの(CFSONLiを加えた時点で(CFSONLiの溶解が一時停滞したので、上記フラスコを恒温槽に投入し、フラスコ内の溶液温度が50℃となるよう加温し、(CFSONLiを溶解させた。約15gの(CFSONLiを加えた時点で(CFSONLiの溶解が再び停滞したので、1,2-ジメトキシエタンをピペットで1滴加えたところ、(CFSONLiは溶解した。さらに(CFSONLiを徐々に加え、所定の(CFSONLiを全量加えた。得られた電解液を20mLメスフラスコに移し、容積が20mLとなるまで1,2-ジメトキシエタンを加えた。これを電解液E1とした。得られた電解液は容積20mLであり、この電解液に含まれる(CFSONLiは18.38gであった。電解液E1における(CFSONLiの濃度は3.2mol/Lであった。電解液E1においては、(CFSONLi1分子に対し1,2-ジメトキシエタン1.6分子が含まれている。 About 5 mL of 1,2-dimethoxyethane, an organic solvent, was placed in a flask equipped with a stir bar and a thermometer. Under stirring conditions, (CF 3 SO 2 ) 2 NLi, which is a lithium salt, was gradually added to 1,2-dimethoxyethane in the flask so as to keep the solution temperature at 40 ° C. or lower and dissolved. When about 13 g of (CF 3 SO 2 ) 2 NLi was added, the dissolution of (CF 3 SO 2 ) 2 NLi temporarily stagnated. Therefore, the flask was put into a thermostat, and the solution temperature in the flask was 50 ° C. (CF 3 SO 2 ) 2 NLi was dissolved. When about 15 g of (CF 3 SO 2 ) 2 NLi was added, the dissolution of (CF 3 SO 2 ) 2 NLi stagnated again, so 1 drop of 1,2-dimethoxyethane was added with a pipette (CF 3 SO 2 ) 2 NLi dissolved. Further, (CF 3 SO 2 ) 2 NLi was gradually added, and the entire amount of predetermined (CF 3 SO 2 ) 2 NLi was added. The resulting electrolyte was transferred to a 20 mL volumetric flask and 1,2-dimethoxyethane was added until the volume was 20 mL. This was designated as an electrolytic solution E1. The obtained electrolytic solution had a volume of 20 mL, and (CF 3 SO 2 ) 2 NLi contained in this electrolytic solution was 18.38 g. The concentration of (CF 3 SO 2 ) 2 NLi in the electrolytic solution E1 was 3.2 mol / L. In the electrolytic solution E1, 1.6 molecules of 1,2-dimethoxyethane are contained with respect to (CF 3 SO 2 ) 2 NLi1 molecules.
 なお、上記製造は不活性ガス雰囲気下のグローブボックス内で行った。 The above production was carried out in a glove box under an inert gas atmosphere.
 (E2)
 16.08gの(CFSONLiを用い、E1と同様の方法で、(CFSONLiの濃度が2.8mol/Lである電解液E2を製造した。電解液E2においては、(CFSONLi1分子に対し1,2-ジメトキシエタン2.1分子が含まれている。
(E2)
Using 16.08 g of (CF 3 SO 2 ) 2 NLi, an electrolytic solution E2 having a concentration of (CF 3 SO 2 ) 2 NLi of 2.8 mol / L was produced in the same manner as E1. In the electrolytic solution E2, 2.1 molecules of 1,2-dimethoxyethane are contained per molecule of (CF 3 SO 2 ) 2 NLi.
 (E3)
 有機溶媒であるアセトニトリル約5mLを、撹拌子を備えたフラスコに入れた。撹拌条件下にて、上記フラスコ中のアセトニトリルに対し、リチウム塩である(CFSONLiを徐々に加え、溶解させた。(CFSONLiを全量で19.52g加えたところで一晩撹拌した。得られた電解液を20mLメスフラスコに移し、容積が20mLとなるまでアセトニトリルを加えた。これを電解液E3とした。なお、上記製造は不活性ガス雰囲気下のグローブボックス内で行った。
(E3)
About 5 mL of acetonitrile, which is an organic solvent, was placed in a flask equipped with a stir bar. Under stirring conditions, (CF 3 SO 2 ) 2 NLi, which is a lithium salt, was gradually added to and dissolved in acetonitrile in the flask. When 19.52 g of (CF 3 SO 2 ) 2 NLi was added in total, the mixture was stirred overnight. The resulting electrolyte was transferred to a 20 mL volumetric flask and acetonitrile was added until the volume was 20 mL. This was designated as an electrolytic solution E3. The production was performed in a glove box under an inert gas atmosphere.
 電解液E3における(CFSONLiの濃度は3.4mol/Lであった。電解液E3においては、(CFSONLi1分子に対しアセトニトリル3分子が含まれている。 The concentration of (CF 3 SO 2 ) 2 NLi in the electrolytic solution E3 was 3.4 mol / L. In the electrolytic solution E3, 3 molecules of acetonitrile are contained with respect to 1 molecule of (CF 3 SO 2 ) 2 NLi.
 (E4)
 24.11gの(CFSONLiを用い、E3と同様の方法で、(CFSONLiの濃度が4.2mol/Lである電解液E4を製造した。電解液E4においては、(CFSONLi1分子に対しアセトニトリル1.9分子が含まれている。
(E4)
Using 24.11 g of (CF 3 SO 2 ) 2 NLi, an electrolytic solution E4 having a concentration of (CF 3 SO 2 ) 2 NLi of 4.2 mol / L was produced in the same manner as E3. In the electrolytic solution E4, 1.9 molecules of acetonitrile are contained with respect to (CF 3 SO 2 ) 2 NLi1 molecules.
 (E5)
 リチウム塩として13.47gの(FSONLiを用い、有機溶媒として1,2-ジメトキシエタンを用いた以外は、E3と同様の方法で、(FSONLiの濃度が3.6mol/Lである電解液E5を製造した。電解液E5においては、(FSONLi1分子に対し1,2-ジメトキシエタン1.9分子が含まれている。
(E5)
Using (FSO 2) 2 NLi of 13.47g as lithium salt, as 1,2 except that dimethoxyethane using an organic solvent, in the same manner as E3, is (FSO 2) concentration of 2 NLi 3.6 mol Electrolyte E5 which is / L was manufactured. In the electrolytic solution E5, 1.9 molecules of 1,2-dimethoxyethane are contained per 1 molecule of (FSO 2 ) 2 NLi.
 (E6)
 14.97gの(FSONLiを用い、E5と同様の方法で、(FSONLiの濃度が4.0mol/Lである電解液E6を製造した。電解液E6においては、(FSONLi1分子に対し1,2-ジメトキシエタン1.5分子が含まれている。
(E6)
Using 14.97 g of (FSO 2 ) 2 NLi, an electrolytic solution E6 having a concentration of (FSO 2 ) 2 NLi of 4.0 mol / L was produced in the same manner as E5. In the electrolytic solution E6, 1.5 molecules of 1,2-dimethoxyethane are contained per 1 molecule of (FSO 2 ) 2 NLi.
 (E7)
 リチウム塩として15.72gの(FSONLiを用いた以外は、E3と同様の方法で、(FSONLiの濃度が4.2mol/Lである電解液E7を製造した。電解液E7においては、(FSONLi1分子に対しアセトニトリル3分子が含まれている。
(E7)
Except for using (FSO 2) 2 NLi of 15.72g as lithium salt, in a similar manner as E3, to produce an electrolyte E7 is (FSO 2) concentration of 2 NLi is 4.2 mol / L. In the electrolytic solution E7, 3 molecules of acetonitrile are contained with respect to 1 molecule of (FSO 2 ) 2 NLi.
 (E8)
 16.83gの(FSONLiを用い、E7と同様の方法で、(FSONLiの濃度が4.5mol/Lである電解液E8を製造した。電解液E8においては、(FSONLi1分子に対しアセトニトリル2.4分子が含まれている。
(E8)
Using 16.83 g of (FSO 2 ) 2 NLi, an electrolytic solution E8 having a concentration of (FSO 2 ) 2 NLi of 4.5 mol / L was produced in the same manner as E7. In the electrolytic solution E8, 2.4 molecules of acetonitrile are contained with respect to (FSO 2 ) 2 NLi1 molecules.
 (E9)
 18.71gの(FSONLiを用い、E7と同様の方法で、(FSONLiの濃度が5.0mol/Lである電解液E9を製造した。電解液E9においては、(FSONLi1分子に対しアセトニトリル2.1分子が含まれている。
(E9)
By using 18.71 g of (FSO 2 ) 2 NLi, an electrolytic solution E9 having a concentration of (FSO 2 ) 2 NLi of 5.0 mol / L was produced in the same manner as E7. In the electrolytic solution E9, 2.1 molecules of acetonitrile are contained with respect to (FSO 2 ) 2 NLi1 molecules.
 (E10)
 20.21gの(FSONLiを用い、E7と同様の方法で、(FSONLiの濃度が5.4mol/Lである電解液E10を製造した。電解液E10においては、(FSONLi1分子に対しアセトニトリル2分子が含まれている。
(E10)
Using 20.21 g of (FSO 2 ) 2 NLi, an electrolytic solution E10 having a concentration of (FSO 2 ) 2 NLi of 5.4 mol / L was produced in the same manner as E7. In the electrolyte solution E10, 2 molecules of acetonitrile are contained with respect to 1 molecule of (FSO 2 ) 2 NLi.
 (E11)
 有機溶媒であるジメチルカーボネート約5mLを、撹拌子を備えたフラスコに入れた。撹拌条件下にて、上記フラスコ中のジメチルカーボネートに対し、リチウム塩である(FSONLiを徐々に加え、溶解させた。(FSONLiを全量で14.64g加えたところで一晩撹拌した。得られた電解液を20mLメスフラスコに移し、容積が20mLとなるまでジメチルカーボネートを加えた。これを電解液E11とした。なお、上記製造は不活性ガス雰囲気下のグローブボックス内で行った。
 電解液E11における(FSONLiの濃度は3.9mol/Lであった。電解液E11においては、(FSONLi1分子に対しジメチルカーボネート2分子が含まれている。
(E11)
About 5 mL of dimethyl carbonate, which is an organic solvent, was placed in a flask equipped with a stir bar. Under stirring conditions, (FSO 2 ) 2 NLi, which is a lithium salt, was gradually added to dimethyl carbonate in the flask and dissolved. When (FSO 2 ) 2 NLi was added in a total amount of 14.64 g, the mixture was stirred overnight. The resulting electrolyte was transferred to a 20 mL volumetric flask and dimethyl carbonate was added until the volume was 20 mL. This was designated as an electrolytic solution E11. The production was performed in a glove box under an inert gas atmosphere.
The concentration of (FSO 2 ) 2 NLi in the electrolytic solution E11 was 3.9 mol / L. In the electrolytic solution E11, two molecules of dimethyl carbonate are contained with respect to one molecule of (FSO 2 ) 2 NLi.
 (E12)
 電解液E11にジメチルカーボネートを加えて希釈し、(FSONLiの濃度が3.4mol/Lの電解液E12とした。電解液E12においては、(FSONLi1分子に対しジメチルカーボネート2.5分子が含まれている。
(E12)
Dimethyl carbonate was added to the electrolytic solution E11 for dilution to obtain an electrolytic solution E12 having a (FSO 2 ) 2 NLi concentration of 3.4 mol / L. In the electrolytic solution E12, 2.5 molecules of dimethyl carbonate are contained with respect to (FSO 2 ) 2 NLi1 molecules.
 (E13)
 電解液E11にジメチルカーボネートを加えて希釈し、(FSONLiの濃度が2.9mol/Lの電解液E13とした。電解液E13においては、(FSONLi1分子に対しジメチルカーボネート3分子が含まれている。
(E13)
Dimethyl carbonate was added to the electrolytic solution E11 for dilution to obtain an electrolytic solution E13 having a (FSO 2 ) 2 NLi concentration of 2.9 mol / L. In the electrolytic solution E13, three molecules of dimethyl carbonate are contained with respect to one molecule of (FSO 2 ) 2 NLi.
 (E14)
 電解液E11にジメチルカーボネートを加えて希釈し、(FSONLiの濃度が2.6mol/Lの電解液E14とした。電解液E14においては、(FSONLi1分子に対しジメチルカーボネート3.5分子が含まれている。
(E14)
Dimethyl carbonate was added to the electrolytic solution E11 for dilution to obtain an electrolytic solution E14 having a concentration of (FSO 2 ) 2 NLi of 2.6 mol / L. In the electrolytic solution E14, 3.5 molecules of dimethyl carbonate are contained with respect to (FSO 2 ) 2 NLi1 molecules.
 (E15)
 電解液E11にジメチルカーボネートを加えて希釈し、(FSONLiの濃度が2.0mol/Lの電解液E15とした。電解液E15においては、(FSONLi1分子に対しジメチルカーボネート5分子が含まれている。
(E15)
Dimethyl carbonate was added to the electrolytic solution E11 for dilution to obtain an electrolytic solution E15 having a (FSO 2 ) 2 NLi concentration of 2.0 mol / L. In the electrolytic solution E15, five molecules of dimethyl carbonate are contained with respect to one molecule of (FSO 2 ) 2 NLi.
 (E16)
 有機溶媒であるエチルメチルカーボネート約5mLを、撹拌子を備えたフラスコに入れた。撹拌条件下にて、上記フラスコ中のエチルメチルカーボネートに対し、リチウム塩である(FSONLiを徐々に加え、溶解させた。(FSONLiを全量で12.81g加えたところで一晩撹拌した。得られた電解液を20mLメスフラスコに移し、容積が20mLとなるまでエチルメチルカーボネートを加えた。これを電解液E16とした。なお、上記製造は不活性ガス雰囲気下のグローブボックス内で行った。
 電解液E16における(FSONLiの濃度は3.4mol/Lであった。電解液E16においては、(FSONLi1分子に対しエチルメチルカーボネート2分子が含まれている。
(E16)
About 5 mL of ethyl methyl carbonate, which is an organic solvent, was placed in a flask equipped with a stir bar. Under stirring conditions, (FSO 2 ) 2 NLi, which is a lithium salt, was gradually added to and dissolved in ethyl methyl carbonate in the flask. When 12.81 g of (FSO 2 ) 2 NLi was added in total, the mixture was stirred overnight. The obtained electrolytic solution was transferred to a 20 mL volumetric flask, and ethyl methyl carbonate was added until the volume became 20 mL. This was designated as an electrolytic solution E16. The production was performed in a glove box under an inert gas atmosphere.
The concentration of (FSO 2 ) 2 NLi in the electrolytic solution E16 was 3.4 mol / L. In the electrolytic solution E16, two molecules of ethyl methyl carbonate are contained with respect to one molecule of (FSO 2 ) 2 NLi.
 (E17)
 電解液E16にエチルメチルカーボネートを加えて希釈し、(FSONLiの濃度が2.9mol/Lの電解液E17とした。電解液E17においては、(FSONLi1分子に対しエチルメチルカーボネート2.5分子が含まれている。
(E17)
The electrolyte solution E16 was diluted by adding ethyl methyl carbonate to obtain an electrolyte solution E17 having a (FSO 2 ) 2 NLi concentration of 2.9 mol / L. In the electrolytic solution E17, 2.5 molecules of ethyl methyl carbonate are contained per 1 molecule of (FSO 2 ) 2 NLi.
 (E18)
 電解液E16にエチルメチルカーボネートを加えて希釈し、(FSONLiの濃度が2.2mol/Lの電解液E18とした。電解液E18においては、(FSONLi1分子に対しエチルメチルカーボネート3.5分子が含まれている。
(E18)
The electrolyte solution E16 was diluted by adding ethyl methyl carbonate to obtain an electrolyte solution E18 having a concentration of (FSO 2 ) 2 NLi of 2.2 mol / L. In the electrolytic solution E18, 3.5 molecules of ethyl methyl carbonate are contained with respect to (FSO 2 ) 2 NLi1 molecules.
 (E19)
 有機溶媒であるジエチルカーボネート約5mLを、撹拌子を備えたフラスコに入れた。撹拌条件下にて、上記フラスコ中のジエチルカーボネートに対し、リチウム塩である(FSONLiを徐々に加え、溶解させた。(FSONLiを全量で11.37g加えたところで一晩撹拌した。得られた電解液を20mLメスフラスコに移し、容積が20mLとなるまでジエチルカーボネートを加えた。これを電解液E19とした。なお、上記製造は不活性ガス雰囲気下のグローブボックス内で行った。
 電解液E19における(FSONLiの濃度は3.0mol/Lであった。電解液E19においては、(FSONLi1分子に対しジエチルカーボネート2分子が含まれている。
(E19)
About 5 mL of diethyl carbonate, which is an organic solvent, was placed in a flask equipped with a stirring bar. Under stirring conditions, (FSO 2 ) 2 NLi, which is a lithium salt, was gradually added to and dissolved in diethyl carbonate in the flask. When 11.37 g of the total amount of (FSO 2 ) 2 NLi was added, the mixture was stirred overnight. The resulting electrolyte was transferred to a 20 mL volumetric flask and diethyl carbonate was added until the volume was 20 mL. This was designated as an electrolytic solution E19. The production was performed in a glove box under an inert gas atmosphere.
The concentration of (FSO 2 ) 2 NLi in the electrolytic solution E19 was 3.0 mol / L. In the electrolytic solution E19, two molecules of diethyl carbonate are contained with respect to one molecule of (FSO 2 ) 2 NLi.
 (E20)
 電解液E19にジエチルカーボネートを加えて希釈し、(FSONLiの濃度が2.6mol/Lの電解液E20とした。電解液E20においては、(FSONLi1分子に対しジエチルカーボネート2.5分子が含まれている。
(E20)
Diethyl carbonate was added to the electrolytic solution E19 for dilution to obtain an electrolytic solution E20 having a (FSO 2 ) 2 NLi concentration of 2.6 mol / L. In the electrolytic solution E20, 2.5 molecules of diethyl carbonate are contained with respect to (FSO 2 ) 2 NLi1 molecules.
 (E21)
 電解液E19にジエチルカーボネートを加えて希釈し、(FSONLiの濃度が2.0mol/Lの電解液E21とした。電解液E21においては、(FSONLi1分子に対しジエチルカーボネート3.5分子が含まれている。
(E21)
Diethyl carbonate was added to the electrolytic solution E19 for dilution to obtain an electrolytic solution E21 having a (FSO 2 ) 2 NLi concentration of 2.0 mol / L. In the electrolytic solution E21, 3.5 molecules of diethyl carbonate are contained with respect to (FSO 2 ) 2 NLi1 molecules.
 (C1)
 5.74gの(CFSONLiを用い、有機溶媒として1,2-ジメトキシエタンを用いた以外は、E3と同様の方法で、(CFSONLiの濃度が1.0mol/Lである電解液C1を製造した。電解液C1においては、(CFSONLi1分子に対し1,2-ジメトキシエタン8.3分子が含まれている。
(C1)
Using (CF 3 SO 2) 2 NLi of 5.74 g, as except for using 1,2-dimethoxyethane organic solvents, in the same manner as E3, is (CF 3 SO 2) concentration of 2 NLi 1. Electrolyte C1 which is 0 mol / L was manufactured. In the electrolytic solution C1, 8.3 molecules of 1,2-dimethoxyethane are contained with respect to (CF 3 SO 2 ) 2 NLi1 molecules.
 (C2)
 5.74gの(CFSONLiを用い、E3と同様の方法で、(CFSONLiの濃度が1.0mol/Lである電解液C2を製造した。電解液C2においては、(CFSONLi1分子に対しアセトニトリル16分子が含まれている。
(C2)
Using 5.74 g of (CF 3 SO 2 ) 2 NLi, an electrolytic solution C2 having a concentration of (CF 3 SO 2 ) 2 NLi of 1.0 mol / L was produced in the same manner as E3. In the electrolytic solution C2, 16 molecules of acetonitrile are contained with respect to (CF 3 SO 2 ) 2 NLi1 molecule.
 (C3)
 3.74gの(FSONLiを用い、E5と同様の方法で、(FSONLiの濃度が1.0mol/Lである電解液C3を製造した。電解液C3においては、(FSONLi1分子に対し1,2-ジメトキシエタン8.8分子が含まれている。
(C3)
Using 3.74 g of (FSO 2 ) 2 NLi, an electrolytic solution C3 having a concentration of (FSO 2 ) 2 NLi of 1.0 mol / L was produced in the same manner as E5. In the electrolytic solution C3, 8.8 molecules of 1,2-dimethoxyethane are contained per molecule of (FSO 2 ) 2 NLi.
 (C4)
 3.74gの(FSONLiを用い、E7と同様の方法で、(FSONLiの濃度が1.0mol/Lである電解液C4を製造した。電解液C4においては、(FSONLi1分子に対しアセトニトリル17分子が含まれている。
(C4)
Using 3.74 g of (FSO 2 ) 2 NLi, an electrolytic solution C4 having a concentration of (FSO 2 ) 2 NLi of 1.0 mol / L was produced in the same manner as E7. In the electrolyte solution C4, 17 molecules of acetonitrile are contained with respect to (FSO 2 ) 2 NLi1 molecule.
 (C5)
 有機溶媒としてエチレンカーボネートおよびジエチルカーボネートの混合溶媒(体積比3:7、以下、「EC/DEC」ということがある。)を用い、リチウム塩として3.04gのLiPFを用いた以外は、E3と同様の方法で、LiPFの濃度が1.0mol/Lである電解液C5を製造した。
(C5)
E3 except that a mixed solvent of ethylene carbonate and diethyl carbonate (volume ratio 3: 7, hereinafter sometimes referred to as “EC / DEC”) was used as the organic solvent and 3.04 g of LiPF 6 was used as the lithium salt. In the same manner, an electrolytic solution C5 having a LiPF 6 concentration of 1.0 mol / L was produced.
 (C6)
 電解液E11にジメチルカーボネートを加えて希釈し、(FSONLiの濃度が1.1mol/Lの電解液C6とした。電解液C6においては、(FSONLi1分子に対しジメチルカーボネート10分子が含まれている。
(C6)
Dimethyl carbonate was added to the electrolytic solution E11 for dilution to obtain an electrolytic solution C6 having a (FSO 2 ) 2 NLi concentration of 1.1 mol / L. In the electrolytic solution C6, 10 molecules of dimethyl carbonate are contained per 1 molecule of (FSO 2 ) 2 NLi.
 (C7)
 電解液E16にエチルメチルカーボネートを加えて希釈し、(FSONLiの濃度が1.1mol/Lの電解液C7とした。電解液C7においては、(FSONLi1分子に対しエチルメチルカーボネート8分子が含まれている。
(C7)
The electrolyte solution E16 was diluted by adding ethyl methyl carbonate to obtain an electrolyte solution C7 having a (FSO 2 ) 2 NLi concentration of 1.1 mol / L. In the electrolytic solution C7, 8 molecules of ethyl methyl carbonate are contained with respect to (FSO 2 ) 2 NLi1 molecule.
 (C8)
 電解液E19にジエチルカーボネートを加えて希釈し、(FSONLiの濃度が1.1mol/Lの電解液C8とした。電解液C8においては、(FSONLi1分子に対しジエチルカーボネート7分子が含まれている。
(C8)
Diethyl carbonate was added to the electrolytic solution E19 for dilution to obtain an electrolytic solution C8 having a (FSO 2 ) 2 NLi concentration of 1.1 mol / L. In the electrolytic solution C8, 7 molecules of diethyl carbonate are contained per 1 molecule of (FSO 2 ) 2 NLi.
 表3に電解液の一覧を示す。 Table 3 shows a list of electrolytes.
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
  (評価例1:IR測定)
 電解液E3、E4、E7、E8、E10、C2、C4、ならびに、アセトニトリル、(CFSONLi、(FSONLiにつき、以下の条件でIR測定を行った。2100~2400cm-1の範囲のIRスペクトルをそれぞれ図1~図10に示す。図の横軸は波数(cm-1)であり、縦軸は吸光度(反射吸光度)である。さらに、電解液E11~E21、電解液C6~C8、ならびに、ジメチルカーボネート、エチルメチルカーボネート、ジエチルカーボネートにつき、以下の条件でIR測定を行った。1900~1600cm-1の範囲のIRスペクトルをそれぞれ図11~図27に示す。また、(FSONLiにつき、1900~1600cm-1の範囲のIRスペクトルを図28に示す。図の横軸は波数(cm-1)であり、縦軸は吸光度(反射吸光度)である。
(Evaluation Example 1: IR measurement)
IR measurement was performed on the electrolytic solutions E3, E4, E7, E8, E10, C2, C4, acetonitrile, (CF 3 SO 2 ) 2 NLi, and (FSO 2 ) 2 NLi under the following conditions. IR spectra in the range of 2100 to 2400 cm −1 are shown in FIGS. 1 to 10, respectively. The horizontal axis in the figure is the wave number (cm −1 ), and the vertical axis is the absorbance (reflection absorbance). Further, IR measurement was performed on the electrolytic solutions E11 to E21, the electrolytic solutions C6 to C8, dimethyl carbonate, ethyl methyl carbonate, and diethyl carbonate under the following conditions. IR spectra in the range of 1900 to 1600 cm −1 are shown in FIGS. 11 to 27, respectively. In addition, FIG. 28 shows an IR spectrum in the range of 1900 to 1600 cm −1 for (FSO 2 ) 2 NLi. The horizontal axis in the figure is the wave number (cm −1 ), and the vertical axis is the absorbance (reflection absorbance).
 IR測定条件
 装置:FT-IR(ブルカーオプティクス社製)
 測定条件:ATR法(ダイヤモンド使用)
 測定雰囲気:不活性ガス雰囲気下
IR measurement conditions Device: FT-IR (Bruker Optics)
Measurement conditions: ATR method (using diamond)
Measurement atmosphere: Inert gas atmosphere
 図8で示されるアセトニトリルのIRスペクトルの2250cm-1付近には、アセトニトリルのCおよびN間の三重結合の伸縮振動に由来する特徴的なピークが観察された。なお、図9で示される(CFSONLiのIRスペクトルおよび図10で示される(FSONLiのIRスペクトルの2250cm-1付近には、特段のピークが観察されなかった。 In the vicinity of 2250 cm −1 in the IR spectrum of acetonitrile shown in FIG. 8, a characteristic peak derived from the stretching vibration of the triple bond between C and N of acetonitrile was observed. Note that no special peak was observed in the vicinity of 2250 cm −1 of the IR spectrum of (CF 3 SO 2 ) 2 NLi shown in FIG. 9 and the IR spectrum of (FSO 2 ) 2 NLi shown in FIG.
 図1で示される電解液E3のIRスペクトルには、2250cm-1付近にアセトニトリルのCおよびN間の三重結合の伸縮振動に由来する特徴的なピークがわずかに(Io=0.00699)観察された。さらに図1のIRスペクトルには、2250cm-1付近から高波数側にシフトした2280cm-1付近にアセトニトリルのCおよびN間の三重結合の伸縮振動に由来する特徴的なピークがピーク強度Is=0.05828で観察された。IsとIoのピーク強度の関係はIs>Ioであり、Is=8×Ioであった。 In the IR spectrum of the electrolyte solution E3 shown in FIG. 1, a characteristic peak derived from the stretching vibration of the triple bond between C and N of acetonitrile is slightly observed (Io = 0.00699) in the vicinity of 2250 cm −1. It was. More IR spectrum of FIG. 1, 2250 cm characteristic peaks peak intensity derived from the stretching vibration of the triple bond between the vicinity of -1 acetonitrile near 2280 cm -1 shifted to the high frequency side C and N Is = 0 .05828. The relationship between the peak intensities of Is and Io was Is> Io, and Is = 8 × Io.
 図2で示される電解液E4のIRスペクトルには、2250cm-1付近にアセトニトリル由来のピークが観察されず、2250cm-1付近から高波数側にシフトした2280cm-1付近にアセトニトリルのCおよびN間の三重結合の伸縮振動に由来する特徴的なピークがピーク強度Is=0.05234で観察された。IsとIoのピーク強度の関係はIs>Ioであった。 The IR spectrum of the electrolyte E4 shown in FIG. 2, 2250 cm -1 peak derived from acetonitrile was not observed in the vicinity, between 2250 cm from the vicinity -1 acetonitrile near 2280 cm -1 shifted to the high frequency side C and N A characteristic peak derived from the stretching vibration of the triple bond was observed at a peak intensity Is = 0.05234. The relationship between the peak intensities of Is and Io was Is> Io.
 図3で示される電解液E7のIRスペクトルには、2250cm-1付近にアセトニトリルのCおよびN間の三重結合の伸縮振動に由来する特徴的なピークがわずかに(Io=0.00997)観察された。さらに図3のIRスペクトルには、2250cm-1付近から高波数側にシフトした2280cm-1付近にアセトニトリルのCおよびN間の三重結合の伸縮振動に由来する特徴的なピークがピーク強度Is=0.08288で観察された。IsとIoのピーク強度の関係はIs>Ioであり、Is=8×Ioであった。図4で示される電解液E8のIRスペクトルについても、図3のIRチャートと同様の強度のピークが同様の波数に観察された。IsとIoのピーク強度の関係はIs>Ioであり、Is=11×Ioであった。 In the IR spectrum of the electrolytic solution E7 shown in FIG. 3, a characteristic peak derived from the stretching vibration of the triple bond between C and N of acetonitrile is slightly observed (Io = 0.00997) in the vicinity of 2250 cm −1. It was. More IR spectrum of FIG. 3, 2250 cm characteristic peaks peak intensity derived from the stretching vibration of the triple bond between the vicinity of -1 acetonitrile near 2280 cm -1 shifted to the high frequency side C and N Is = 0 .08288. The relationship between the peak intensities of Is and Io was Is> Io, and Is = 8 × Io. Also in the IR spectrum of the electrolytic solution E8 shown in FIG. 4, the same intensity peak as that in the IR chart of FIG. 3 was observed at the same wave number. The relationship between the peak intensities of Is and Io was Is> Io, and Is = 11 × Io.
 図5で示される電解液E10のIRスペクトルには、2250cm-1付近にアセトニトリル由来のピークが観察されず、2250cm-1付近から高波数側にシフトした2280cm-1付近にアセトニトリルのCおよびN間の三重結合の伸縮振動に由来する特徴的なピークがピーク強度Is=0.07350で観察された。IsとIoのピーク強度の関係はIs>Ioであった。 FIG The IR spectrum of the electrolyte E10 represented by 5, is not a peak derived from acetonitrile observed around 2250 cm -1, inter 2250 cm from the vicinity -1 shifted acetonitrile 2280cm around -1 to the high frequency side C and N A characteristic peak derived from the stretching vibration of the triple bond was observed at a peak intensity Is = 0.07350. The relationship between the peak intensities of Is and Io was Is> Io.
 図6で示される電解液C2のIRスペクトルには、図8と同じく、2250cm-1付近にアセトニトリルのCおよびN間の三重結合の伸縮振動に由来する特徴的なピークがピーク強度Io=0.04441で観察された。さらに図6のIRスペクトルには、2250cm-1付近から高波数側にシフトした2280cm-1付近にアセトニトリルのCおよびN間の三重結合の伸縮振動に由来する特徴的なピークがピーク強度Is=0.03018で観察された。IsとIoのピーク強度の関係はIs<Ioであった。 In the IR spectrum of the electrolytic solution C2 shown in FIG. 6, a characteristic peak derived from the stretching vibration of the triple bond between C and N of acetonitrile is observed in the vicinity of 2250 cm −1 in the IR spectrum of FIG. Observed at 04441. More IR spectrum of FIG. 6, 2250 cm characteristic peaks peak intensity derived from the stretching vibration of the triple bond between the vicinity of -1 acetonitrile near 2280 cm -1 shifted to the high frequency side C and N Is = 0 .03018. The relationship between peak intensities of Is and Io was Is <Io.
 図7で示される電解液C4のIRスペクトルには、図8と同じく、2250cm-1付近にアセトニトリルのCおよびN間の三重結合の伸縮振動に由来する特徴的なピークがピーク強度Io=0.04975で観察された。さらに図7のIRスペクトルには、2250cm-1付近から高波数側にシフトした2280cm-1付近にアセトニトリルのCおよびN間の三重結合の伸縮振動に由来する特徴的なピークがピーク強度Is=0.03804で観察された。IsとIoのピーク強度の関係はIs<Ioであった。 In the IR spectrum of the electrolytic solution C4 shown in FIG. 7, a characteristic peak derived from the stretching vibration of the triple bond between C and N of acetonitrile is observed in the vicinity of 2250 cm −1 in the IR spectrum of FIG. Observed at 04975. More IR spectrum of Figure 7, 2250 cm characteristic peaks peak intensity derived from the stretching vibration of the triple bond between the vicinity of -1 acetonitrile near 2280 cm -1 shifted to the high frequency side C and N Is = 0 .03804. The relationship between peak intensities of Is and Io was Is <Io.
 図17で示されるジメチルカーボネートのIRスペクトルの1750cm-1付近には、ジメチルカーボネートのCおよびO間の二重結合の伸縮振動に由来する特徴的なピークが観察された。なお、図28で示される(FSONLiのIRスペクトルの1750cm-1付近には、特段のピークが観察されなかった。 In the vicinity of 1750 cm −1 of the IR spectrum of dimethyl carbonate shown in FIG. 17, a characteristic peak derived from the stretching vibration of the double bond between C and O of dimethyl carbonate was observed. Note that no special peak was observed in the vicinity of 1750 cm −1 in the IR spectrum of (FSO 2 ) 2 NLi shown in FIG.
 図11で示される電解液E11のIRスペクトルには、1750cm-1付近にジメチルカーボネートのCおよびO間の二重結合の伸縮振動に由来する特徴的なピークがわずかに(Io=0.16628)観察された。さらに図11のIRスペクトルには、1750cm-1付近から低波数側にシフトした1717cm-1付近にジメチルカーボネートのCおよびO間の二重結合の伸縮振動に由来する特徴的なピークがピーク強度Is=0.48032で観察された。IsとIoのピーク強度の関係はIs>Ioであり、Is=2.89×Ioであった。 In the IR spectrum of the electrolytic solution E11 shown in FIG. 11, a characteristic peak derived from the stretching vibration of the double bond between C and O of dimethyl carbonate is slightly present at around 1750 cm −1 (Io = 0.166628). Observed. More IR spectrum of Figure 11, characteristic peaks peak intensity Is derived from stretching vibration of double bonds between C and O of dimethyl carbonate in the vicinity of 1717 cm -1 shifted from the vicinity of 1750 cm -1 to a lower wavenumber side = 0.48032. The relationship between the peak intensities of Is and Io was Is> Io, and Is = 2.89 × Io.
 図12で示される電解液E12のIRスペクトルには、1750cm-1付近にジメチルカーボネートのCおよびO間の二重結合の伸縮振動に由来する特徴的なピークがわずかに(Io=0.18129)観察された。さらに図12のIRスペクトルには、1750cm-1付近から低波数側にシフトした1717cm-1付近にジメチルカーボネートのCおよびO間の二重結合の伸縮振動に由来する特徴的なピークがピーク強度Is=0.52005で観察された。IsとIoのピーク強度の関係はIs>Ioであり、Is=2.87×Ioであった。 In the IR spectrum of the electrolytic solution E12 shown in FIG. 12, a characteristic peak derived from stretching vibration of a double bond between C and O of dimethyl carbonate is slightly present (Io = 0.18129) in the vicinity of 1750 cm −1. Observed. More IR spectrum of Figure 12, characteristic peaks peak intensity Is derived from stretching vibration of double bonds between C and O of dimethyl carbonate in the vicinity of 1717 cm -1 shifted from the vicinity of 1750 cm -1 to a lower wavenumber side = 0.52005 was observed. The relationship between the peak intensities of Is and Io was Is> Io, and Is = 2.87 × Io.
 図13で示される電解液E13のIRスペクトルには、1750cm-1付近にジメチルカーボネートのCおよびO間の二重結合の伸縮振動に由来する特徴的なピークがわずかに(Io=0.20293)観察された。さらに図13のIRスペクトルには、1750cm-1付近から低波数側にシフトした1717cm-1付近にジメチルカーボネートのCおよびO間の二重結合の伸縮振動に由来する特徴的なピークがピーク強度Is=0.53091で観察された。IsとIoのピーク強度の関係はIs>Ioであり、Is=2.62×Ioであった。 In the IR spectrum of the electrolytic solution E13 shown in FIG. 13, a characteristic peak derived from the stretching vibration of the double bond between C and O of dimethyl carbonate is slightly present in the vicinity of 1750 cm −1 (Io = 0.20293). Observed. More IR spectrum of Figure 13, characteristic peaks peak intensity Is derived from stretching vibration of double bonds between C and O of dimethyl carbonate in the vicinity of 1717 cm -1 shifted from the vicinity of 1750 cm -1 to a lower wavenumber side = 0.53091. The relationship between the peak intensities of Is and Io was Is> Io, and Is = 2.62 × Io.
 図14で示される電解液E14のIRスペクトルには、1750cm-1付近にジメチルカーボネートのCおよびO間の二重結合の伸縮振動に由来する特徴的なピークがわずかに(Io=0.23891)観察された。さらに図14のIRスペクトルには、1750cm-1付近から低波数側にシフトした1717cm-1付近にジメチルカーボネートのCおよびO間の二重結合の伸縮振動に由来する特徴的なピークがピーク強度Is=0.53098で観察された。IsとIoのピーク強度の関係はIs>Ioであり、Is=2.22×Ioであった。 In the IR spectrum of the electrolytic solution E14 shown in FIG. 14, there is a slight characteristic peak (Io = 0.38991) derived from the stretching vibration of the double bond between C and O of dimethyl carbonate in the vicinity of 1750 cm −1. Observed. More IR spectrum of Figure 14, characteristic peaks peak intensity Is derived from stretching vibration of double bonds between C and O of dimethyl carbonate in the vicinity of 1717 cm -1 shifted from the vicinity of 1750 cm -1 to a lower wavenumber side = 0.53098. The relationship between the peak intensities of Is and Io was Is> Io, and Is = 2.22 × Io.
 図15で示される電解液E15のIRスペクトルには、1750cm-1付近にジメチルカーボネートのCおよびO間の二重結合の伸縮振動に由来する特徴的なピークがわずかに(Io=0.30514)観察された。さらに図15のIRスペクトルには、1750cm-1付近から低波数側にシフトした1717cm-1付近にジメチルカーボネートのCおよびO間の二重結合の伸縮振動に由来する特徴的なピークがピーク強度Is=0.50223で観察された。IsとIoのピーク強度の関係はIs>Ioであり、Is=1.65×Ioであった。 In the IR spectrum of the electrolytic solution E15 shown in FIG. 15, a characteristic peak derived from the stretching vibration of the double bond between C and O of dimethyl carbonate is slightly present at around 1750 cm −1 (Io = 0.050514). Observed. More IR spectrum of Figure 15, characteristic peaks peak intensity Is derived from stretching vibration of double bonds between C and O of dimethyl carbonate in the vicinity of 1717 cm -1 shifted from the vicinity of 1750 cm -1 to a lower wavenumber side = 0.50223. The relationship between the peak intensities of Is and Io was Is> Io, and Is = 1.65 × Io.
 図16で示される電解液C6のIRスペクトルには、1750cm-1付近にジメチルカーボネートのCおよびO間の二重結合の伸縮振動に由来する特徴的なピークが(Io=0.48204)観察された。さらに図16のIRスペクトルには、1750cm-1付近から低波数側にシフトした1717cm-1付近にジメチルカーボネートのCおよびO間の二重結合の伸縮振動に由来する特徴的なピークがピーク強度Is=0.39244で観察された。IsとIoのピーク強度の関係はIs<Ioであった。 In the IR spectrum of the electrolytic solution C6 shown in FIG. 16, a characteristic peak (Io = 0.48204) derived from the stretching vibration of the double bond between C and O of dimethyl carbonate is observed around 1750 cm −1. It was. More IR spectrum of Figure 16, characteristic peaks peak intensity Is derived from stretching vibration of double bonds between C and O of dimethyl carbonate in the vicinity of 1717 cm -1 shifted from the vicinity of 1750 cm -1 to a lower wavenumber side = 0.39244. The relationship between peak intensities of Is and Io was Is <Io.
 図22で示されるエチルメチルカーボネートのIRスペクトルの1745cm-1付近には、エチルメチルカーボネートのCおよびO間の二重結合の伸縮振動に由来する特徴的なピークが観察された。 In the vicinity of 1745 cm −1 of the IR spectrum of ethylmethyl carbonate shown in FIG. 22, a characteristic peak derived from the stretching vibration of the double bond between C and O of ethylmethyl carbonate was observed.
 図18で示される電解液E16のIRスペクトルには、1745cm-1付近にエチルメチルカーボネートのCおよびO間の二重結合の伸縮振動に由来する特徴的なピークがわずかに(Io=0.13582)観察された。さらに図18のIRスペクトルには、1745cm-1付近から低波数側にシフトした1711cm-1付近にエチルメチルカーボネートのCおよびO間の二重結合の伸縮振動に由来する特徴的なピークがピーク強度Is=0.45888で観察された。IsとIoのピーク強度の関係はIs>Ioであり、Is=3.38×Ioであった。 In the IR spectrum of the electrolytic solution E16 shown in FIG. 18, a characteristic peak derived from the stretching vibration of the double bond between C and O of ethylmethyl carbonate is slightly observed at around 1745 cm −1 (Io = 0.13582). ) Observed. Further, in the IR spectrum of FIG. 18, a characteristic peak derived from the stretching vibration of the double bond between C and O of ethylmethyl carbonate is observed near 1711 cm −1 shifted from the vicinity of 1745 cm −1 to the lower wavenumber side. Observed at Is = 0.45888. The relationship between the peak intensities of Is and Io was Is> Io, and Is = 3.38 × Io.
 図19で示される電解液E17のIRスペクトルには、1745cm-1付近にエチルメチルカーボネートのCおよびO間の二重結合の伸縮振動に由来する特徴的なピークがわずかに(Io=0.15151)観察された。さらに図19のIRスペクトルには、1745cm-1付近から低波数側にシフトした1711cm-1付近にエチルメチルカーボネートのCおよびO間の二重結合の伸縮振動に由来する特徴的なピークがピーク強度Is=0.48779で観察された。IsとIoのピーク強度の関係はIs>Ioであり、Is=3.22×Ioであった。 In the IR spectrum of the electrolytic solution E17 shown in FIG. 19, there is a slight characteristic peak (Io = 0.151151) derived from the stretching vibration of the double bond between C and O of ethylmethyl carbonate in the vicinity of 1745 cm −1. ) Observed. Further, in the IR spectrum of FIG. 19, a characteristic peak derived from the stretching vibration of the double bond between C and O of ethylmethyl carbonate is observed at about 1711 cm −1 shifted from the vicinity of 1745 cm −1 to the lower wavenumber side. Observed at Is = 0.48779. The relationship between the peak intensities of Is and Io was Is> Io, and Is = 3.22 × Io.
 図20で示される電解液E18のIRスペクトルには、1745cm-1付近にエチルメチルカーボネートのCおよびO間の二重結合の伸縮振動に由来する特徴的なピークがわずかに(Io=0.20191)観察された。さらに図20のIRスペクトルには、1745cm-1付近から低波数側にシフトした1711cm-1付近にエチルメチルカーボネートのCおよびO間の二重結合の伸縮振動に由来する特徴的なピークがピーク強度Is=0.48407で観察された。IsとIoのピーク強度の関係はIs>Ioであり、Is=2.40×Ioであった。 In the IR spectrum of the electrolytic solution E18 shown in FIG. 20, there is a slight characteristic peak (Io = 0.20191) derived from the stretching vibration of the double bond between C and O of ethylmethyl carbonate in the vicinity of 1745 cm −1. ) Observed. Further, in the IR spectrum of FIG. 20, a characteristic peak derived from the stretching vibration of the double bond between C and O of ethylmethyl carbonate is observed near 1711 cm −1 shifted from the vicinity of 1745 cm −1 to the lower wavenumber side. Observed at Is = 0.408407. The relationship between the peak intensities of Is and Io was Is> Io, and Is = 2.40 × Io.
 図21で示される電解液C7のIRスペクトルには、1745cm-1付近にエチルメチルカーボネートのCおよびO間の二重結合の伸縮振動に由来する特徴的なピークが(Io=0.41907)観察された。さらに図21のIRスペクトルには、1745cm-1付近から低波数側にシフトした1711cm-1付近にエチルメチルカーボネートのCおよびO間の二重結合の伸縮振動に由来する特徴的なピークがピーク強度Is=
0.33929で観察された。IsとIoのピーク強度の関係はIs<Ioであった。
In the IR spectrum of the electrolytic solution C7 shown in FIG. 21, a characteristic peak (Io = 0.41907) derived from stretching vibration of a double bond between C and O of ethylmethyl carbonate was observed in the vicinity of 1745 cm −1. It was done. Furthermore, in the IR spectrum of FIG. 21, a characteristic peak derived from the stretching vibration of the double bond between C and O of ethylmethyl carbonate is observed at about 1711 cm −1 shifted from the vicinity of 1745 cm −1 to the lower wavenumber side. Is =
Observed at 0.33929. The relationship between peak intensities of Is and Io was Is <Io.
 図27で示されるジエチルカーボネートのIRスペクトルの1742cm-1付近には、ジエチルカーボネートのCおよびO間の二重結合の伸縮振動に由来する特徴的なピークが観察された。 In the vicinity of 1742 cm −1 of the IR spectrum of diethyl carbonate shown in FIG. 27, a characteristic peak derived from the stretching vibration of the double bond between C and O of diethyl carbonate was observed.
 図23で示される電解液E19のIRスペクトルには、1742cm-1付近にジエチルカーボネートのCおよびO間の二重結合の伸縮振動に由来する特徴的なピークがわずかに(Io=0.11202)観察された。さらに図23のIRスペクトルには、1742cm-1付近から低波数側にシフトした1706cm-1付近にジエチルカーボネートのCおよびO間の二重結合の伸縮振動に由来する特徴的なピークがピーク強度Is=0.42925で観察された。IsとIoのピーク強度の関係はIs>Ioであり、Is=3.83×Ioであった。 In the IR spectrum of the electrolytic solution E19 shown in FIG. 23, a characteristic peak derived from the stretching vibration of the double bond between C and O of diethyl carbonate is slightly present in the vicinity of 1742 cm −1 (Io = 0.12002). Observed. Further, in the IR spectrum of FIG. 23, a characteristic peak derived from the stretching vibration of the double bond between C and O of diethyl carbonate is observed near 1706 cm −1 shifted from the vicinity of 1742 cm −1 to the low wavenumber side. = 0.42925. The relationship between the peak intensities of Is and Io was Is> Io, and Is = 3.83 × Io.
 図24で示される電解液E20のIRスペクトルには、1742cm-1付近にジエチルカーボネートのCおよびO間の二重結合の伸縮振動に由来する特徴的なピークがわずかに(Io=0.15231)観察された。さらに図24のIRスペクトルには、1742cm-1付近から低波数側にシフトした1706cm-1付近にジエチルカーボネートのCおよびO間の二重結合の伸縮振動に由来する特徴的なピークがピーク強度Is=0.45679で観察された。IsとIoのピーク強度の関係はIs>Ioであり、Is=3.00×Ioであった。 In the IR spectrum of the electrolytic solution E20 shown in FIG. 24, a characteristic peak derived from the stretching vibration of the double bond between C and O of diethyl carbonate is slightly present in the vicinity of 1742 cm −1 (Io = 0.15231). Observed. Further, in the IR spectrum of FIG. 24, a characteristic peak derived from the stretching vibration of the double bond between C and O of diethyl carbonate is observed near the peak intensity Is near 1706 cm −1 shifted from the vicinity of 1742 cm −1 to the low wavenumber side. = 0.45679. The relationship between the peak intensities of Is and Io was Is> Io, and Is = 3.00 × Io.
 図25で示される電解液E21のIRスペクトルには、1742cm-1付近にジエチルカーボネートのCおよびO間の二重結合の伸縮振動に由来する特徴的なピークがわずかに(Io=0.20337)観察された。さらに図25のIRスペクトルには、1742cm-1付近から低波数側にシフトした1706cm-1付近にジエチルカーボネートのCおよびO間の二重結合の伸縮振動に由来する特徴的なピークがピーク強度Is=0.43841で観察された。IsとIoのピーク強度の関係はIs>Ioであり、Is=2.16×Ioであった。 In the IR spectrum of the electrolytic solution E21 shown in FIG. 25, a characteristic peak derived from the stretching vibration of the double bond between C and O of diethyl carbonate is slightly present in the vicinity of 1742 cm −1 (Io = 0.20337). Observed. Further, in the IR spectrum of FIG. 25, a characteristic peak derived from the stretching vibration of the double bond between C and O of diethyl carbonate is observed near the peak intensity Is near 1706 cm −1 shifted from near 1742 cm −1 to the low wavenumber side. = 0.43841. The relationship between the peak intensities of Is and Io was Is> Io, and Is = 2.16 × Io.
 図26で示される電解液C8のIRスペクトルには、1742cm-1付近にジエチルカーボネートのCおよびO間の二重結合の伸縮振動に由来する特徴的なピークが(Io=0.39636)観察された。さらに図26のIRスペクトルには、1742cm-1付近から低波数側にシフトした1709cm-1付近にジエチルカーボネートのCおよびO間の二重結合の伸縮振動に由来する特徴的なピークがピーク強度Is=0.31129で観察された。IsとIoのピーク強度の関係はIs<Ioであった。 In the IR spectrum of the electrolytic solution C8 shown in FIG. 26, a characteristic peak (Io = 0.39636) derived from the stretching vibration of the double bond between C and O of diethyl carbonate is observed near 1742 cm −1. It was. More IR spectrum of Figure 26, characteristic peaks peak intensity Is derived from stretching vibration of double bonds between C and O in diethyl carbonate in the vicinity of 1709 cm -1 shifted from the vicinity of 1742 cm -1 to a lower wavenumber side = 0.31129. The relationship between peak intensities of Is and Io was Is <Io.
  (評価例2:ラマンスペクトル測定)
 電解液E8、E9、C4、並びに、E11、E13、E15、C6につき、以下の条件でラマンスペクトル測定を行った。各電解液の金属塩のアニオン部分に由来するピークが観察されたラマンスペクトルをそれぞれ図29~図35に示す。図の横軸は波数(cm-1)であり、縦軸は散乱強度である。
 ラマンスペクトル測定条件
 装置:レーザーラマン分光光度計(日本分光株式会社NRSシリーズ)
 レーザー波長:532nm
 不活性ガス雰囲気下で電解液を石英セルに密閉し、測定に供した。
(Evaluation example 2: Raman spectrum measurement)
For the electrolytes E8, E9, C4, and E11, E13, E15, C6, Raman spectrum measurement was performed under the following conditions. FIGS. 29 to 35 show Raman spectra in which peaks derived from the anion portion of the metal salt of each electrolytic solution were observed. In the figure, the horizontal axis represents the wave number (cm −1 ), and the vertical axis represents the scattering intensity.
Raman spectrum measurement conditions Equipment: Laser Raman spectrophotometer (NRS series, JASCO Corporation)
Laser wavelength: 532 nm
The electrolyte was sealed in a quartz cell under an inert gas atmosphere and used for measurement.
 図29~図31で示される電解液E8、E9、C4のラマンスペクトルの700~800cm-1には、アセトニトリルに溶解したLiFSAの(FSONに由来する特徴的なピークが観察された。ここで、図29~図31から、LiFSAの濃度の増加に伴い、上記ピークが高波数側にシフトするのがわかる。電解液が高濃度化するに従い、塩のアニオンに該当する(FSONが、Liと相互作用する状態になる、換言すると、濃度が低い場合はLiとアニオンはSSIP(Solvent-separated ion pairs)状態を主に形成しており、高濃度化に伴いCIP(Contact ion pairs)状態やAGG(aggregate)状態を主に形成していると推察される。そして、かかる状態の変化がラマンスペクトルのピークシフトとして観察されたと考察できる。 A characteristic peak derived from (FSO 2 ) 2 N of LiFSA dissolved in acetonitrile was observed in 700 to 800 cm −1 of the Raman spectra of the electrolytic solutions E8, E9, and C4 shown in FIGS. . Here, it can be seen from FIGS. 29 to 31 that the peak shifts to the higher wavenumber side as the LiFSA concentration increases. As the electrolyte concentration increases, (FSO 2 ) 2 N corresponding to the anion of the salt becomes in a state of interacting with Li. In other words, when the concentration is low, Li and the anion become SSIP (Solvent-separated ion). It is presumed that the CIP (Contact ion pairs) state and the AGG (aggregate) state are mainly formed as the concentration is increased. It can be considered that such a change in the state was observed as a peak shift of the Raman spectrum.
 図32~図35で示される電解液E11、E13、E15、C6のラマンスペクトルの700~800cm-1には、ジメチルカーボネートに溶解したLiFSAの(FSONに由来する特徴的なピークが観察された。ここで、図32~図35から、LiFSAの濃度の増加に伴い、上記ピークが高波数側にシフトするのがわかる。この現象は、前段落で考察したのと同様に、電解液が高濃度化することで、塩のアニオンに該当する(FSONが複数のLiと相互作用している状態がスペクトルに反映された結果であると推察される。 A characteristic peak derived from (FSO 2 ) 2 N of LiFSA dissolved in dimethyl carbonate is observed in 700 to 800 cm −1 of the Raman spectra of the electrolytic solutions E11, E13, E15, and C6 shown in FIGS. Observed. Here, it can be seen from FIGS. 32 to 35 that the peak shifts to the higher wavenumber side as the concentration of LiFSA increases. This phenomenon is similar to that discussed in the previous paragraph. When the concentration of the electrolyte is increased, the state in which (FSO 2 ) 2 N corresponding to the anion of the salt interacts with a plurality of Li is shown in the spectrum. It is inferred that the result is reflected.
  (評価例3:イオン伝導度)
 電解液E1、E2、E4~E6、E8、E11、E16、E19のイオン伝導度を以下の条件で測定した。結果を表4に示す。
(Evaluation Example 3: Ionic conductivity)
The ionic conductivities of the electrolytic solutions E1, E2, E4 to E6, E8, E11, E16, and E19 were measured under the following conditions. The results are shown in Table 4.
 イオン伝導度測定条件
 Ar雰囲気下、白金極を備えたセル定数既知のガラス製セルに、電解液を封入し、30℃、1kHzでのインピーダンスを測定した。インピーダンスの測定結果から、イオン伝導度を算出した。測定機器はSolartron 147055BEC(ソーラトロン社)を使用した。
Ionic conductivity measurement conditions In an Ar atmosphere, an electrolytic solution was sealed in a glass cell with a platinum constant and a known cell constant, and impedance at 30 ° C. and 1 kHz was measured. The ion conductivity was calculated from the impedance measurement result. As the measuring instrument, Solartron 147055BEC (Solartron) was used.
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000004
 電解液E1、E2、E4~E6、E8、E11、E16およびE19は、いずれもイオン伝導性を示した。よって、本発明の電解液は、いずれも各種の電池の電解液として機能し得ると理解できる。 Electrolytes E1, E2, E4 to E6, E8, E11, E16 and E19 all exhibited ionic conductivity. Therefore, it can be understood that the electrolytic solution of the present invention can function as an electrolytic solution for various batteries.
  (評価例4:粘度)
 電解液E1、E2、E4~6、E8、E11、E16、E19、ならびにC1~C4、C6~C8の粘度を以下の条件で測定した。結果を表5に示す。
(Evaluation Example 4: Viscosity)
The viscosities of the electrolytic solutions E1, E2, E4 to 6, E8, E11, E16, E19, and C1 to C4, C6 to C8 were measured under the following conditions. The results are shown in Table 5.
 粘度測定条件
 落球式粘度計(AntonPaar GmbH(アントンパール社)製 Lovis 2000M)を用い、Ar雰囲気下、試験セルに電解液を封入し、30℃の条件下で粘度を測定した。
Viscosity measurement conditions Using a falling ball viscometer (Lovis 2000M manufactured by Anton Paar GmbH (Anton Paar)), an electrolytic solution was sealed in a test cell under an Ar atmosphere, and the viscosity was measured at 30 ° C.
Figure JPOXMLDOC01-appb-T000005
Figure JPOXMLDOC01-appb-T000005
 電解液E1、E2、E4~6、E8、E11、E16、E19の粘度は、電解液C1~C4、C6~C8の粘度と比較して、著しく高かった。よって、本発明の電解液を用いた電池であれば、仮に電池が破損したとしても、電解液漏れが抑制される。 The viscosities of electrolytic solutions E1, E2, E4 to 6, E8, E11, E16, and E19 were significantly higher than those of electrolytic solutions C1 to C4 and C6 to C8. Therefore, if the battery uses the electrolytic solution of the present invention, leakage of the electrolytic solution is suppressed even if the battery is damaged.
  (評価例5:揮発性)
 電解液E2、E4、E8、E11、E13、C1、C2、C4およびC6の揮発性を以下の方法で測定した。
 約10mgの電解液をアルミニウム製のパンに入れ、熱重量測定装置(TAインスツルメント社製、SDT600)に配置し、室温での電解液の重量変化を測定した。重量変化(質量%)を時間で微分することで揮発速度を算出した。揮発速度のうち最大のものを選択し、表6に示した。
(Evaluation Example 5: Volatility)
The volatility of the electrolytic solutions E2, E4, E8, E11, E13, C1, C2, C4 and C6 was measured by the following method.
About 10 mg of the electrolytic solution was placed in an aluminum pan and placed in a thermogravimetric measuring device (TA Instruments, SDT600), and the weight change of the electrolytic solution at room temperature was measured. The volatilization rate was calculated by differentiating the weight change (mass%) with time. The maximum volatilization rate was selected and shown in Table 6.
Figure JPOXMLDOC01-appb-T000006
Figure JPOXMLDOC01-appb-T000006
 電解液E2、E4、E8、E11、E13の最大揮発速度は、電解液C1、C2、C4、C6の最大揮発速度と比較して、著しく小さかった。よって、本発明の電解液を用いた電池は、仮に損傷したとしても、電解液の揮発速度が小さいため、電池外への有機溶媒の急速な揮発が抑制される。 The maximum volatilization rates of the electrolytic solutions E2, E4, E8, E11, and E13 were significantly smaller than the maximum volatilization rates of the electrolytic solutions C1, C2, C4, and C6. Therefore, even if the battery using the electrolytic solution of the present invention is damaged, the volatilization rate of the electrolytic solution is small, so that rapid volatilization of the organic solvent to the outside of the battery is suppressed.
  (評価例6:燃焼性)
 電解液E4、C2の燃焼性を以下の方法で試験した。
 電解液をガラスフィルターにピペットで3滴滴下し、電解液をガラスフィルターに保持させた。当該ガラスフィルターをピンセットで把持し、そして、当該ガラスフィルターに接炎させた。
 電解液E4は15秒間接炎させても引火しなかった。他方、電解液C2は5秒余りで燃え尽きた。
 本発明の電解液は燃焼しにくいことが裏付けられた。
(Evaluation Example 6: Combustibility)
The flammability of the electrolytes E4 and C2 was tested by the following method.
Three drops of the electrolytic solution were dropped onto the glass filter with a pipette, and the electrolytic solution was held on the glass filter. The glass filter was held with tweezers, and the glass filter was brought into contact with flame.
Electrolyte E4 did not ignite even when indirect flame was applied for 15 seconds. On the other hand, the electrolytic solution C2 burned out in about 5 seconds.
It was confirmed that the electrolytic solution of the present invention is difficult to burn.
 以下、非水電解質二次電池(1)および非水電解質二次電池(2)について具体的に説明する。以下の実施例およびEB、CBは便宜的に項目を分けて説明しているため、重複している場合がある。また、以下の実施例および後述するEB、CBは、非水電解質二次電池(1)および非水電解質二次電池(2)の両方の実施例に該当する場合がある。
 (EB1)
 電解液E8を用いたハーフセルを以下のとおり製造した。
 活物質である平均粒径10μmの黒鉛90質量部、および結着剤であるポリフッ化ビニリデン10質量部を混合した。この混合物を適量のN-メチル-2-ピロリドンに分散させて、スラリーを作製した。集電体として厚み20μmの銅箔を準備した。この銅箔の表面に、ドクターブレードを用いて、上記スラリーを膜状に塗布した。スラリーが塗布された銅箔を乾燥してN-メチル-2-ピロリドンを除去し、その後、銅箔をプレスし、接合物を得た。得られた接合物を真空乾燥機で120℃、6時間加熱乾燥して、活物質層が形成された銅箔を得た。これを作用極とした。
 対極は金属Liとした。
 作用極、対極、両者の間に挟装したセパレータとしての厚さ400μmのWhatmanガラス繊維濾紙および電解液E8を電池ケース(宝泉株式会社製 CR2032型コインセルケース)に収容して非水電解質二次電池EB1を得た。この非水電解質二次電池は評価用の非水電解質二次電池であり、ハーフセルとも呼ばれる。
Hereinafter, the nonaqueous electrolyte secondary battery (1) and the nonaqueous electrolyte secondary battery (2) will be specifically described. The following examples, EB, and CB are described separately for convenience, and may overlap. In addition, the following examples and EB and CB described later may correspond to both examples of the nonaqueous electrolyte secondary battery (1) and the nonaqueous electrolyte secondary battery (2).
(EB1)
A half cell using the electrolytic solution E8 was produced as follows.
90 parts by mass of graphite having an average particle diameter of 10 μm as an active material and 10 parts by mass of polyvinylidene fluoride as a binder were mixed. This mixture was dispersed in an appropriate amount of N-methyl-2-pyrrolidone to prepare a slurry. A copper foil having a thickness of 20 μm was prepared as a current collector. The slurry was applied in a film form on the surface of the copper foil using a doctor blade. The copper foil coated with the slurry was dried to remove N-methyl-2-pyrrolidone, and then the copper foil was pressed to obtain a bonded product. The obtained joined product was heat-dried at 120 ° C. for 6 hours with a vacuum dryer to obtain a copper foil on which an active material layer was formed. This was the working electrode.
The counter electrode was metal Li.
A nonaqueous electrolyte secondary containing a Workingman, counter electrode, Whatman glass fiber filter paper having a thickness of 400 μm and an electrolyte E8 sandwiched between the two in a battery case (CR2032 type coin cell case manufactured by Hosen Co., Ltd.). Battery EB1 was obtained. This non-aqueous electrolyte secondary battery is a non-aqueous electrolyte secondary battery for evaluation, and is also called a half cell.
 (CB1)
 電解液C5を用いた以外は、EB1と同様の方法で、非水電解質二次電池CB1を製造した。
(CB1)
A nonaqueous electrolyte secondary battery CB1 was produced in the same manner as in EB1, except that the electrolytic solution C5 was used.
  (評価例7:レート特性)
 EB1、CB1のレート特性を以下の方法で試験した。
 各非水電解質二次電池に対し、0.1C、0.2C、0.5C、1C、2Cレート(1Cとは一定電流において1時間で電池を完全充電または放電させるために要する電流値を意味する。)で充電を行った後に放電を行い、それぞれの速度における作用極の容量(放電容量)を測定した。なお、ここでの記述は、対極を負極、作用極を正極とみなしている。0.1Cレートでの作用極の容量に対する他のレートにおける容量の割合(レート特性)を算出した。結果を表7に示す。
(Evaluation Example 7: Rate characteristics)
The rate characteristics of EB1 and CB1 were tested by the following method.
For each non-aqueous electrolyte secondary battery, 0.1 C, 0.2 C, 0.5 C, 1 C, 2 C rate (1 C means the current value required to fully charge or discharge the battery in one hour at a constant current. )) And then discharging, and the capacity (discharge capacity) of the working electrode at each speed was measured. In this description, the counter electrode is regarded as a negative electrode and the working electrode is regarded as a positive electrode. The ratio (rate characteristic) of the capacity at other rates to the capacity of the working electrode at the 0.1 C rate was calculated. The results are shown in Table 7.
Figure JPOXMLDOC01-appb-T000007
Figure JPOXMLDOC01-appb-T000007
 EB1は、0.2C、0.5C、1C、2Cのいずれのレートにおいても、CB1と比較して、容量の低下が抑制されており、優れたレート特性を示した。本発明の電解液を使用した二次電池は、優れたレート特性を示すことが裏付けられた。 EB1 exhibited a superior rate characteristic as compared to CB1, with a decrease in capacity suppressed at any rate of 0.2C, 0.5C, 1C, and 2C. It was confirmed that the secondary battery using the electrolytic solution of the present invention exhibits excellent rate characteristics.
  (評価例8:急速充放電の繰り返しに対する応答性)
 非水電解質二次電池EB1およびCB1に対し、1Cレートで充放電を3回繰り返した際の、容量と電圧の変化を観察した。結果を図36に示す。
(Evaluation Example 8: Responsiveness to repeated rapid charge / discharge)
For the nonaqueous electrolyte secondary batteries EB1 and CB1, changes in capacity and voltage were observed when charging and discharging were repeated three times at a 1C rate. The results are shown in FIG.
 CB1は充放電を繰り返すに伴い、1Cレートで電流を流した場合の分極が大きくなる傾向があり、2Vから0.01Vに到達するまでに得られる容量が急速に低下した。他方、EB1は充放電を繰り返しても、図36において3本の曲線が重なっている様からも確認できるように分極の増減がほとんどなく、好適に容量を維持した。CB1において分極が増加した理由として、急速に充放電を繰り返した際の電解液中に生じたLi濃度ムラに因り、電極との反応界面に十分な量のLiを電解液が供給できなくなったこと、つまり、電解液のLi濃度の偏在が考えられる。EB1では、Li濃度が高い本発明の電解液を用いたことで、電解液のLi濃度の偏在を抑制できたものと考えられる。本発明の電解液を使用した二次電池は、急速充放電に対し、優れた応答性を示すことが裏付けられた。 CB1 has a tendency to increase the polarization when a current is passed at a rate of 1C as charging and discharging are repeated, and the capacity obtained from reaching 2V to 0.01V rapidly decreases. On the other hand, even when EB1 was repeatedly charged and discharged, there was almost no increase / decrease in polarization as can be confirmed from the overlapping of the three curves in FIG. The reason why the polarization increased in CB1 was that the electrolyte solution could not supply a sufficient amount of Li to the reaction interface with the electrode due to the Li concentration unevenness generated in the electrolyte solution when the charge and discharge were repeated rapidly. That is, the uneven distribution of Li concentration in the electrolytic solution can be considered. In EB1, it is considered that the uneven distribution of the Li concentration of the electrolytic solution could be suppressed by using the electrolytic solution of the present invention having a high Li concentration. It was confirmed that the secondary battery using the electrolytic solution of the present invention exhibits excellent responsiveness to rapid charge / discharge.
  (評価例9:Li輸率)
 電解液E2、E8、C4およびC5のLi輸率を以下の条件で測定した。結果を表8に示す。
(Evaluation example 9: Li transportation rate)
The Li transport numbers of the electrolytic solutions E2, E8, C4 and C5 were measured under the following conditions. The results are shown in Table 8.
(Li輸率測定条件)
 電解液を入れたNMR管をPFG-NMR装置(ECA-500、日本電子)に供し、Li、19Fを対象として、スピンエコー法を用い、磁場パルス幅を変化させながら、各電解液中のLiイオンおよびアニオンの拡散係数を測定した。Li輸率は以下の式で算出した。
 Li輸率=(Liイオン拡散係数)/(Liイオン拡散係数+アニオン拡散係数)
(Li transport rate measurement conditions)
The NMR tube containing the electrolyte was supplied to a PFG-NMR apparatus (ECA-500, JEOL), and 7 Li, 19 F was used as a target in each electrolyte while changing the magnetic field pulse width using the spin echo method. The diffusion coefficients of Li ions and anions were measured. The Li transport number was calculated by the following formula.
Li transport number = (Li ion diffusion coefficient) / (Li ion diffusion coefficient + anion diffusion coefficient)
Figure JPOXMLDOC01-appb-T000008
Figure JPOXMLDOC01-appb-T000008
 電解液E2、E8のLi輸率は、電解液C4、C5のLi輸率と比較して、著しく高かった。ここで、電解液のLiイオン伝導度は、電解液に含まれるイオン伝導度(全イオン電導度)にLi輸率を乗じて算出することができる。そうすると、本発明の電解液は、同程度のイオン伝導度を示す従来の電解液と比較して、リチウムイオン(カチオン)の輸送速度が高いといえる。
 また、電解液E8につき、温度を変化させた場合のLi輸率を、上記Li輸率測定条件に準じて測定した。結果を表9に示す。
Figure JPOXMLDOC01-appb-T000009
 表9の結果から、本発明の電解液は、温度に因らず、好適なLi輸率を保つことがわかる。本発明の電解液は、低温でも液体状態を保っているといえる。
The Li transport number of the electrolytic solutions E2 and E8 was significantly higher than the Li transport number of the electrolytic solutions C4 and C5. Here, the Li ion conductivity of the electrolytic solution can be calculated by multiplying the ionic conductivity (total ionic conductivity) contained in the electrolytic solution by the Li transport number. If it does so, it can be said that the electrolyte solution of this invention has the high transport rate of lithium ion (cation) compared with the conventional electrolyte solution which shows comparable ionic conductivity.
Moreover, about electrolyte solution E8, the Li transport number at the time of changing temperature was measured according to the said Li transport number measurement conditions. The results are shown in Table 9.
Figure JPOXMLDOC01-appb-T000009
From the results in Table 9, it can be seen that the electrolytic solution of the present invention maintains a suitable Li transport number regardless of the temperature. It can be said that the electrolytic solution of the present invention maintains a liquid state even at a low temperature.
〔非水電解質二次電池〕
 (EB2)
 電解液E8を用いた非水電解質二次電池EB2を以下のとおり製造した。
[Nonaqueous electrolyte secondary battery]
(EB2)
Nonaqueous electrolyte secondary battery EB2 using electrolytic solution E8 was produced as follows.
 正極活物質であるLiNi5/10Co2/10Mn3/10で表される層状岩塩構造のリチウム含有金属酸化物94質量部、導電助剤であるアセチレンブラック3質量部、および結着剤であるポリフッ化ビニリデン3質量部を混合した。この混合物を適量のN-メチル-2-ピロリドンに分散させて、スラリーを作製した。正極集電体として厚み20μmのアルミニウム箔(JIS A1000番系)を準備した。このアルミニウム箔の表面に、ドクターブレードを用いて上記スラリーが膜状になるように塗布した。スラリーが塗布されたアルミニウム箔を80℃で20分間乾燥することでN-メチル-2-ピロリドンを揮発により除去した。その後、このアルミニウム箔をプレスし接合物を得た。得られた接合物を真空乾燥機で120℃、6時間加熱乾燥して、正極活物質層が形成されたアルミニウム箔を得た。これを正極とした。以下、必要に応じて、LiNi5/10Co2/10Mn3/10で表される層状岩塩構造のリチウム含有金属酸化物をNCM523と略し、アセチレンブラックをABと略し、ポリフッ化ビニリデンをPVdFと略する。 94 parts by mass of a lithium-containing metal oxide having a layered rock salt structure represented by LiNi 5/10 Co 2/10 Mn 3/10 O 2 as a positive electrode active material, 3 parts by mass of acetylene black as a conductive auxiliary agent, and a binder 3 parts by mass of polyvinylidene fluoride as an agent was mixed. This mixture was dispersed in an appropriate amount of N-methyl-2-pyrrolidone to prepare a slurry. An aluminum foil (JIS A1000 series) having a thickness of 20 μm was prepared as a positive electrode current collector. The slurry was applied to the surface of the aluminum foil using a doctor blade so as to form a film. The aluminum foil coated with the slurry was dried at 80 ° C. for 20 minutes to remove N-methyl-2-pyrrolidone by volatilization. Thereafter, this aluminum foil was pressed to obtain a bonded product. The obtained joined product was heat-dried at 120 ° C. for 6 hours with a vacuum dryer to obtain an aluminum foil on which a positive electrode active material layer was formed. This was used as a positive electrode. Hereinafter, as necessary, a lithium-containing metal oxide having a layered rock salt structure represented by LiNi 5/10 Co 2/10 Mn 3/10 O 2 is abbreviated as NCM523, acetylene black is abbreviated as AB, and polyvinylidene fluoride is abbreviated. Abbreviated as PVdF.
 負極活物質である天然黒鉛98質量部、ならびに結着剤であるスチレンブタジエンゴム1質量部およびカルボキシメチルセルロース1質量部を混合した。この混合物を適量のイオン交換水に分散させて、スラリーを作製した。負極集電体として厚み20μmの銅箔を準備した。この銅箔の表面に、ドクターブレードを用いて、上記スラリーを膜状に塗布した。スラリーが塗布された銅箔を乾燥して水を除去し、その後、銅箔をプレスし、接合物を得た。得られた接合物を真空乾燥機で100℃、6時間加熱乾燥して、負極活物質層が形成された銅箔を得た。これを負極とした。以下、必要に応じて、スチレンブタジエンゴムをSBRと略し、カルボキシメチルセルロースをCMCと略する。 98 parts by mass of natural graphite as a negative electrode active material, 1 part by mass of styrene butadiene rubber as a binder, and 1 part by mass of carboxymethyl cellulose were mixed. This mixture was dispersed in an appropriate amount of ion-exchanged water to prepare a slurry. A copper foil having a thickness of 20 μm was prepared as a negative electrode current collector. The slurry was applied in a film form on the surface of the copper foil using a doctor blade. The copper foil coated with the slurry was dried to remove water, and then the copper foil was pressed to obtain a bonded product. The obtained joined product was dried by heating at 100 ° C. for 6 hours with a vacuum dryer to obtain a copper foil on which a negative electrode active material layer was formed. This was used as a negative electrode. Hereinafter, styrene butadiene rubber is abbreviated as SBR and carboxymethyl cellulose is abbreviated as CMC as necessary.
 セパレータとして、厚さ20μmのセルロース製不織布を準備した。
 正極と負極とでセパレータを挟持し、極板群とした。この極板群を二枚一組のラミネートフィルムで覆い、三辺をシールした後、袋状となったラミネートフィルムに電解液E8を注入した。その後、残りの一辺をシールすることで、四辺が気密にシールされ、極板群および電解液が密閉された非水電解質二次電池を得た。この電池を非水電解質二次電池EB2とした。
A cellulose nonwoven fabric having a thickness of 20 μm was prepared as a separator.
A separator was sandwiched between the positive electrode and the negative electrode to form an electrode plate group. The electrode plate group was covered with a set of two laminated films, and the three sides were sealed, and then the electrolyte solution E8 was injected into the laminated film in a bag shape. Thereafter, the remaining one side was sealed to obtain a nonaqueous electrolyte secondary battery in which the four sides were hermetically sealed and the electrode plate group and the electrolyte were sealed. This battery was designated as a nonaqueous electrolyte secondary battery EB2.
 (EB3)
 電解液E8を用いた非水電解質二次電池EB3を以下のとおり製造した。
(EB3)
A nonaqueous electrolyte secondary battery EB3 using the electrolytic solution E8 was produced as follows.
 正極は、非水電解質二次電池EB2の正極と同様に製造した。
 負極活物質である天然黒鉛90質量部、および結着剤であるポリフッ化ビニリデン10質量部を混合した。この混合物を適量のイオン交換水に分散させて、スラリーを作製した。負極集電体として厚み20μmの銅箔を準備した。この銅箔の表面に、ドクターブレードを用いて、上記スラリーを膜状に塗布した。スラリーが塗布された銅箔を乾燥して水を除去し、その後、銅箔をプレスし、接合物を得た。得られた接合物を真空乾燥機で120℃、6時間加熱乾燥して、負極活物質層が形成された銅箔を得た。これを負極とした。
The positive electrode was manufactured in the same manner as the positive electrode of the nonaqueous electrolyte secondary battery EB2.
90 parts by mass of natural graphite as a negative electrode active material and 10 parts by mass of polyvinylidene fluoride as a binder were mixed. This mixture was dispersed in an appropriate amount of ion-exchanged water to prepare a slurry. A copper foil having a thickness of 20 μm was prepared as a negative electrode current collector. The slurry was applied in a film form on the surface of the copper foil using a doctor blade. The copper foil coated with the slurry was dried to remove water, and then the copper foil was pressed to obtain a bonded product. The obtained joined product was heat-dried at 120 ° C. for 6 hours with a vacuum dryer to obtain a copper foil on which a negative electrode active material layer was formed. This was used as a negative electrode.
 セパレータとして、厚さ20μmのセルロース製不織布を準備した。
 正極と負極とでセパレータを挟持し、極板群とした。この極板群を二枚一組のラミネートフィルムで覆い、三辺をシールした後、袋状となったラミネートフィルムに電解液E8を注入した。その後、残りの一辺をシールすることで、ラミネートフィルムの四辺がシールされ、極板群および電解液が当該ラミネートフィルム内に密閉された非水電解質二次電池を得た。この電池を非水電解質二次電池EB3とした。
A cellulose nonwoven fabric having a thickness of 20 μm was prepared as a separator.
A separator was sandwiched between the positive electrode and the negative electrode to form an electrode plate group. The electrode plate group was covered with a set of two laminated films, and the three sides were sealed, and then the electrolyte solution E8 was injected into the laminated film in a bag shape. Thereafter, the remaining one side was sealed to obtain a nonaqueous electrolyte secondary battery in which the four sides of the laminate film were sealed, and the electrode plate group and the electrolyte were sealed in the laminate film. This battery was designated as a nonaqueous electrolyte secondary battery EB3.
 (CB2)
 電解液C5を用いた以外は、EB2と同様に、非水電解質二次電池CB2を製造した。
(CB2)
A nonaqueous electrolyte secondary battery CB2 was produced in the same manner as EB2, except that the electrolytic solution C5 was used.
 (CB3)
 電解液C5を用いた以外は、EB3と同様に、非水電解質二次電池CB3を製造した。
(CB3)
A nonaqueous electrolyte secondary battery CB3 was produced in the same manner as EB3 except that the electrolytic solution C5 was used.
  (評価例10:非水電解質二次電池の入出力特性)
 非水電解質二次電池EB2、EB3、CB2、CB3の出力特性を以下の条件で評価した。
(Evaluation Example 10: Input / output characteristics of non-aqueous electrolyte secondary battery)
The output characteristics of the nonaqueous electrolyte secondary batteries EB2, EB3, CB2, and CB3 were evaluated under the following conditions.
(1)0℃または25℃、SOC80%での入力特性評価
 評価条件は、充電状態(SOC)80%、0℃または25℃、使用電圧範囲3V―4.2V、容量13.5mAhとした。入力特性の評価は、2秒入力と5秒入力について電池毎にそれぞれ3回行った。
(1) Evaluation of input characteristics at 0 ° C. or 25 ° C. and SOC 80% Evaluation conditions were 80% charge state (SOC), 0 ° C. or 25 ° C., operating voltage range 3V-4.2V, and capacity 13.5 mAh. The input characteristics were evaluated three times for each battery for a 2-second input and a 5-second input.
 また、各電池の体積に基づき、25℃、2秒入力における電池出力密度(W/L)を算出した。 Also, based on the volume of each battery, the battery output density (W / L) at 25 ° C. for 2 seconds was calculated.
 入力特性の評価結果を表10に示す。表10の中の「2秒入力」は、充電開始から2秒後での入力を意味し、「5秒入力」は充電開始から5秒後での入力を意味している。 Table 10 shows the evaluation results of the input characteristics. In Table 10, “2 seconds input” means an input 2 seconds after the start of charging, and “5 seconds input” means an input 5 seconds after the start of charging.
 表10に示すように、温度の違いに関わらず、EB2の入力はCB2の入力に比べて、著しく高かった。同様に、EB3の入力はCB3の入力に比べて、著しく高かった。 As shown in Table 10, the EB2 input was significantly higher than the CB2 input regardless of the temperature difference. Similarly, EB3 input was significantly higher than CB3 input.
 また、EB2の電池入力密度はCB2の電池入力密度に比べて、著しく高かった。同様に、EB3の電池入力密度はCB3の電池入力密度に比べて、著しく高かった。 Also, the battery input density of EB2 was significantly higher than the battery input density of CB2. Similarly, the battery input density of EB3 was significantly higher than that of CB3.
(2)0℃または25℃、SOC20%での出力特性評価
 評価条件は、充電状態(SOC)20%、0℃または25℃、使用電圧範囲3V―4.2V、容量13.5mAhとした。SOC20%、0℃は、例えば、冷蔵室などで使用する場合のように出力特性が出にくい領域である。出力特性の評価は、2秒出力と5秒出力について電池毎にそれぞれ3回行った。
(2) Evaluation of output characteristics at 0 ° C. or 25 ° C. and SOC 20% The evaluation conditions were the state of charge (SOC) 20%, 0 ° C. or 25 ° C., operating voltage range 3V-4.2V, and capacity 13.5 mAh. SOC 20%, 0 ° C. is a region where output characteristics are difficult to be obtained, for example, when used in a refrigerator room. The output characteristics were evaluated three times for each battery for the 2-second output and 5-second output.
 また、各電池の体積に基づき、25℃、2秒出力における電池出力密度(W/L)を算出した。 Also, based on the volume of each battery, the battery output density (W / L) at 25 ° C. for 2 seconds output was calculated.
 出力特性の評価結果を表10に示す。表10の中の「2秒出力」は、放電開始から2秒後での出力を意味し、「5秒出力」は放電開始から5秒後での出力を意味している。 Table 10 shows the evaluation results of the output characteristics. In Table 10, “2 seconds output” means an output 2 seconds after the start of discharge, and “5 seconds output” means an output 5 seconds after the start of discharge.
 表10に示すように、温度の違いに関わらず、EB2の出力はCB2の出力に比べて著しく高かった。同様に、EB3の出力はCB3の出力に比べて、著しく高かった。 As shown in Table 10, the output of EB2 was significantly higher than that of CB2 regardless of the difference in temperature. Similarly, the output of EB3 was significantly higher than that of CB3.
 また、EB2の電池出力密度はCB2の電池出力密度に比べて著しく高かった。同様に、EB3の電池出力密度はCB3の電池出力密度に比べて著しく高かった。 Also, the battery output density of EB2 was significantly higher than that of CB2. Similarly, the battery output density of EB3 was significantly higher than that of CB3.
Figure JPOXMLDOC01-appb-T000010
Figure JPOXMLDOC01-appb-T000010
  (評価例11:低温試験)
 電解液E11、E13、E16、E19をそれぞれ容器に入れ、不活性ガスを充填して密閉した。これらを-30℃の冷凍庫に2日間保管した。保管後に各電解液を観察した。いずれの電解液も固化せず液体状態を維持しており、塩の析出も観察されなかった。
(Evaluation Example 11: Low temperature test)
Electrolytes E11, E13, E16, and E19 were placed in containers, filled with an inert gas, and sealed. These were stored in a freezer at −30 ° C. for 2 days. Each electrolyte was observed after storage. None of the electrolytes were solidified and maintained in a liquid state, and no salt deposition was observed.
 (実施例1-1)
 電解液E8を用いた実施例1-1の非水電解質二次電池を以下のとおり製造した。正極は、非水電解質二次電池EB2の正極と同様に製造した。
Example 1-1
A nonaqueous electrolyte secondary battery of Example 1-1 using the electrolytic solution E8 was produced as follows. The positive electrode was manufactured in the same manner as the positive electrode of the nonaqueous electrolyte secondary battery EB2.
 負極活物質である天然黒鉛98質量部、ならびに結着剤であるSBR1質量部およびCMC1質量部を混合した。この混合物を適量のイオン交換水に分散させて、スラリーを作製した。負極集電体として厚み20μmの銅箔を準備した。この銅箔の表面に、ドクターブレードを用いて、上記スラリーを膜状に塗布した。スラリーが塗布された銅箔を乾燥して水を除去し、その後、銅箔をプレスし、接合物を得た。得られた接合物を真空乾燥機で100℃、6時間加熱乾燥して、負極活物質層が形成された銅箔を得た。これを負極とした。 98 parts by mass of natural graphite as a negative electrode active material, and 1 part by mass of SBR and 1 part by mass of CMC as binders were mixed. This mixture was dispersed in an appropriate amount of ion-exchanged water to prepare a slurry. A copper foil having a thickness of 20 μm was prepared as a negative electrode current collector. The slurry was applied in a film form on the surface of the copper foil using a doctor blade. The copper foil coated with the slurry was dried to remove water, and then the copper foil was pressed to obtain a bonded product. The obtained joined product was dried by heating at 100 ° C. for 6 hours with a vacuum dryer to obtain a copper foil on which a negative electrode active material layer was formed. This was used as a negative electrode.
 セパレータとして、実験用濾紙(東洋濾紙株式会社、セルロース製、厚み260μm)を準備した。
 正極と負極とでセパレータを挟持し、極板群とした。この極板群を二枚一組のラミネートフィルムで覆い、三辺をシールした後、袋状となったラミネートフィルムに電解液E8を注入した。その後、残りの一辺をシールすることで、四辺が気密にシールされ、極板群および電解液が密閉された非水電解質二次電池を得た。この電池を実施例1-1の非水電解質二次電池とした。
As a separator, experimental filter paper (Toyo Filter Paper Co., Ltd., cellulose, thickness 260 μm) was prepared.
A separator was sandwiched between the positive electrode and the negative electrode to form an electrode plate group. The electrode plate group was covered with a set of two laminated films, and the three sides were sealed, and then the electrolyte solution E8 was injected into the laminated film in a bag shape. Thereafter, the remaining one side was sealed to obtain a nonaqueous electrolyte secondary battery in which the four sides were hermetically sealed and the electrode plate group and the electrolyte were sealed. This battery was designated as the nonaqueous electrolyte secondary battery of Example 1-1.
 (実施例1-2)
 実施例1-2の非水電解質二次電池は、電解液として電解液E4を用いたこと以外は実施例1-1の非水電解質二次電池と同じものである。実施例1-2の非水電解質二次電池における電解液は、溶媒としてのアセトニトリルに、支持塩としての(SOCFNLi(LiTFSA)を溶解してなる。電解液1リットルに含まれるリチウム塩の濃度は、4.2mol/Lである。電解液は、リチウム塩1分子に対して、2分子のアセトニトリルを含む。
Example 1-2
The nonaqueous electrolyte secondary battery of Example 1-2 is the same as the nonaqueous electrolyte secondary battery of Example 1-1 except that the electrolytic solution E4 was used as the electrolytic solution. The electrolytic solution in the nonaqueous electrolyte secondary battery of Example 1-2 is obtained by dissolving (SO 2 CF 3 ) 2 NLi (LiTFSA) as a supporting salt in acetonitrile as a solvent. The concentration of the lithium salt contained in 1 liter of the electrolytic solution is 4.2 mol / L. The electrolytic solution contains two molecules of acetonitrile with respect to one molecule of the lithium salt.
 (実施例1-3)
 実施例1-3の非水電解質二次電池は、電解液として電解液E11を用いたこと以外は実施例1-1の非水電解質二次電池と同じものである。実施例1-3の非水電解質二次電池における電解液は、溶媒としてのDMCに、支持塩としてのLiFSAを溶解してなる。電解液1リットルに含まれるリチウム塩の濃度は、3.9mol/Lである。電解液は、リチウム塩1分子に対して、2分子のDMCを含む。
(Example 1-3)
The nonaqueous electrolyte secondary battery of Example 1-3 is the same as the nonaqueous electrolyte secondary battery of Example 1-1 except that the electrolytic solution E11 was used as the electrolytic solution. The electrolyte solution in the nonaqueous electrolyte secondary battery of Example 1-3 is obtained by dissolving LiFSA as a supporting salt in DMC as a solvent. The concentration of the lithium salt contained in 1 liter of the electrolytic solution is 3.9 mol / L. The electrolytic solution contains two molecules of DMC with respect to one molecule of the lithium salt.
 (実施例1-4)
 実施例1-4の非水電解質二次電池は電解液E11を用いたものである。実施例1-4の非水電解質二次電池は、電解液の種類、正極活物質と導電助剤と結着剤との混合比、負極活物質と結着剤との混合比、およびセパレータ以外は実施例1-1の非水電解質二次電池と同じものである。正極については、正極活物質としてNCM523を用い、正極用の導電助剤としてABを用い、結着剤としてはPVdFを用いた。これは実施例1-1と同様である。これらの配合比は、NCM523:AB:PVdF=90:8:2であった。正極における活物質層の目付量は5.5mg/cmであり、密度は2.5g/cmであった。これは以下の実施例1-5~1-7および比較例1-2、1-3についても同様である。
 負極については、負極活物質として天然黒鉛を用い、負極用の結着材としてSBRおよびCMCを用いた。これもまた実施例1-1と同様である。これらの配合比は、天然黒鉛:SBR:CMC=98:1:1であった。負極における活物質層の目付量は3.8mg/cmであり、密度は1.1g/cmであった。これは以下の実施例1-5~1-7および比較例1-2、1-3についても同様である。
 セパレータとしては厚さ20μmのセルロース製不織布を用いた。
 実施例1-4の非水電解質二次電池における電解液は、溶媒としてのDMCに、支持塩としてのLiFSAを溶解してなる。電解液1リットルに含まれるリチウム塩の濃度は、3.9mol/Lである。電解液は、リチウム塩1分子に対して、2分子のDMCを含む。
(Example 1-4)
The non-aqueous electrolyte secondary battery of Example 1-4 uses the electrolytic solution E11. The non-aqueous electrolyte secondary battery of Example 1-4 includes the type of electrolyte, the mixing ratio of the positive electrode active material, the conductive additive, and the binder, the mixing ratio of the negative electrode active material and the binder, and other than the separator. These are the same as the nonaqueous electrolyte secondary battery of Example 1-1. For the positive electrode, NCM523 was used as the positive electrode active material, AB was used as the conductive additive for the positive electrode, and PVdF was used as the binder. This is the same as in Example 1-1. These compounding ratios were NCM523: AB: PVdF = 90: 8: 2. The basis weight of the active material layer in the positive electrode was 5.5 mg / cm 2 and the density was 2.5 g / cm 3 . The same applies to Examples 1-5 to 1-7 and Comparative Examples 1-2 and 1-3 below.
For the negative electrode, natural graphite was used as the negative electrode active material, and SBR and CMC were used as the binder for the negative electrode. This is also the same as in Example 1-1. These compounding ratios were natural graphite: SBR: CMC = 98: 1: 1. The basis weight of the active material layer in the negative electrode was 3.8 mg / cm 2 , and the density was 1.1 g / cm 3 . The same applies to Examples 1-5 to 1-7 and Comparative Examples 1-2 and 1-3 below.
A cellulose nonwoven fabric with a thickness of 20 μm was used as the separator.
The electrolyte solution in the nonaqueous electrolyte secondary battery of Example 1-4 is obtained by dissolving LiFSA as a supporting salt in DMC as a solvent. The concentration of the lithium salt contained in 1 liter of the electrolytic solution is 3.9 mol / L. The electrolytic solution contains two molecules of DMC with respect to one molecule of the lithium salt.
 (実施例1-5)
 実施例1-5の非水電解質二次電池は電解液E8を用いたものである。実施例1-5の非水電解質二次電池は、正極活物質と導電助剤と結着剤との混合比、負極活物質と結着剤との混合比、およびセパレータ以外は実施例1-1の非水電解質二次電池と同じものである。正極については、NCM523:AB:PVdF=90:8:2とした。負極については、天然黒鉛:SBR:CMC=98:1:1とした。セパレータとしては厚さ20μmのセルロース製不織布を用いた。
(Example 1-5)
The non-aqueous electrolyte secondary battery of Example 1-5 uses the electrolytic solution E8. The non-aqueous electrolyte secondary battery of Example 1-5 is the same as Example 1 except for the mixing ratio of the positive electrode active material, the conductive additive and the binder, the mixing ratio of the negative electrode active material and the binder, and the separator. 1 is the same as the nonaqueous electrolyte secondary battery. About the positive electrode, it was set as NCM523: AB: PVdF = 90: 8: 2. The negative electrode was natural graphite: SBR: CMC = 98: 1: 1. A cellulose nonwoven fabric with a thickness of 20 μm was used as the separator.
 (実施例1-6)
 実施例1-6の非水電解質二次電池は電解液E11を用いたものである。実施例1-6の非水電解質二次電池は、電解液の種類、正極活物質と導電助剤と結着剤との混合比、負極用の結着材の種類、負極活物質と結着剤との混合比、およびセパレータ以外は実施例1-1の非水電解質二次電池と同じものである。正極については、NCM523:AB:PVdF=90:8:2とした。負極については、負極活物質として天然黒鉛を用い、負極用の結着材としてポリアクリル酸(PAA)を用いた。これらの配合比は、天然黒鉛:PAA=90:10であった。セパレータとしては厚さ20μmのセルロース製不織布を用いた。
(Example 1-6)
The non-aqueous electrolyte secondary battery of Example 1-6 uses the electrolytic solution E11. The non-aqueous electrolyte secondary battery of Example 1-6 includes the type of electrolytic solution, the mixing ratio of the positive electrode active material, the conductive additive, and the binder, the type of binder for the negative electrode, and the negative electrode active material and the binder. Except for the mixing ratio with the agent and the separator, the non-aqueous electrolyte secondary battery of Example 1-1 is the same. About the positive electrode, it was set as NCM523: AB: PVdF = 90: 8: 2. For the negative electrode, natural graphite was used as the negative electrode active material, and polyacrylic acid (PAA) was used as the binder for the negative electrode. These compounding ratios were natural graphite: PAA = 90: 10. A cellulose nonwoven fabric with a thickness of 20 μm was used as the separator.
 (実施例1-7)
 実施例1-7の非水電解質二次電池は電解液E8を用いたものである。実施例1-7の非水電解質二次電池は、正極活物質と導電助剤と結着剤との混合比、負極用の結着材の種類、負極活物質と結着剤との混合比、およびセパレータ以外は実施例1-1の非水電解質二次電池と同じものである。正極については、NCM523:AB:PVdF=90:8:2とした。負極については、天然黒鉛:PAA=90:10とした。セパレータとしては厚さ20μmのセルロース製不織布を用いた。
 (実施例1-8)
 実施例1-8の非水電解質二次電池は電解液E13を用いたものである。実施例1-8の非水電解質二次電池は、正極活物質と導電助剤との混合比、負極用の結着材の種類、負極活物質と結着剤との混合比、およびセパレータ以外は実施例1-1の非水電解質二次電池と同じものである。正極については、NCM523:AB:PVdF=90:8:2とした。負極については、天然黒鉛:SBR:CMC=98:1:1とした。セパレータとしては厚さ20μmのセルロース製不織布を用いた。
(Example 1-7)
The non-aqueous electrolyte secondary battery of Example 1-7 uses the electrolytic solution E8. In the nonaqueous electrolyte secondary battery of Example 1-7, the mixing ratio of the positive electrode active material, the conductive additive and the binder, the type of the binder for the negative electrode, the mixing ratio of the negative electrode active material and the binder The separator is the same as the nonaqueous electrolyte secondary battery of Example 1-1 except for the separator. About the positive electrode, it was set as NCM523: AB: PVdF = 90: 8: 2. The negative electrode was natural graphite: PAA = 90: 10. A cellulose nonwoven fabric with a thickness of 20 μm was used as the separator.
(Example 1-8)
The nonaqueous electrolyte secondary battery of Example 1-8 uses the electrolytic solution E13. The non-aqueous electrolyte secondary battery of Example 1-8 has a mixing ratio of the positive electrode active material and the conductive additive, the type of the binder for the negative electrode, the mixing ratio of the negative electrode active material and the binder, and other than the separator. These are the same as the nonaqueous electrolyte secondary battery of Example 1-1. About the positive electrode, it was set as NCM523: AB: PVdF = 90: 8: 2. The negative electrode was natural graphite: SBR: CMC = 98: 1: 1. A cellulose nonwoven fabric with a thickness of 20 μm was used as the separator.
 (比較例1-1)
 比較例1-1の非水電解質二次電池は、電解液として電解液C5を用いた以外は、実施例1-1と同様である。
(Comparative Example 1-1)
The nonaqueous electrolyte secondary battery of Comparative Example 1-1 is the same as Example 1-1 except that the electrolytic solution C5 was used as the electrolytic solution.
 (比較例1-2)
 比較例1-2の非水電解質二次電池は、電解液C5を用いたものである。比較例1-2の非水電解質二次電池は、電解液の種類、正極活物質と導電助剤と結着剤との混合比、負極活物質と結着剤との混合比、およびセパレータ以外は実施例1-1の非水電解質二次電池と同じものである。正極については、NCM523:AB:PVdF=90:8:2とした。負極については、天然黒鉛:SBR:CMC=98:1:1とした。セパレータとしては厚さ20μmのセルロース製不織布を用いた。
(Comparative Example 1-2)
The non-aqueous electrolyte secondary battery of Comparative Example 1-2 uses an electrolytic solution C5. The non-aqueous electrolyte secondary battery of Comparative Example 1-2 is different from the electrolyte type, the mixing ratio of the positive electrode active material, the conductive additive and the binder, the mixing ratio of the negative electrode active material and the binder, and the separator. These are the same as the nonaqueous electrolyte secondary battery of Example 1-1. About the positive electrode, it was set as NCM523: AB: PVdF = 90: 8: 2. The negative electrode was natural graphite: SBR: CMC = 98: 1: 1. A cellulose nonwoven fabric with a thickness of 20 μm was used as the separator.
 (比較例1-3)
 比較例1-3の非水電解質二次電池は電解液C5を用いたものである。比較例1-3の非水電解質二次電池は、電解液の種類、正極活物質と導電助剤と結着剤との混合比、負極用の結着材の種類、負極活物質と結着剤との混合比、およびセパレータ以外は実施例1-1の非水電解質二次電池と同じものである。正極については、NCM523:AB:PVdF=90:8:2とした。負極については、天然黒鉛:PAA=90:10とした。セパレータとしては厚さ20μmのセルロース製不織布を用いた。
 実施例および比較例の電池構成を表11に示す。
(Comparative Example 1-3)
The non-aqueous electrolyte secondary battery of Comparative Example 1-3 uses the electrolytic solution C5. The non-aqueous electrolyte secondary battery of Comparative Example 1-3 includes the type of electrolyte, the mixing ratio of the positive electrode active material, the conductive auxiliary agent, and the binder, the type of binder for the negative electrode, and the binding with the negative electrode active material. Except for the mixing ratio with the agent and the separator, the non-aqueous electrolyte secondary battery of Example 1-1 is the same. About the positive electrode, it was set as NCM523: AB: PVdF = 90: 8: 2. The negative electrode was natural graphite: PAA = 90: 10. A cellulose nonwoven fabric with a thickness of 20 μm was used as the separator.
Table 11 shows battery configurations of Examples and Comparative Examples.
Figure JPOXMLDOC01-appb-T000011
Figure JPOXMLDOC01-appb-T000011
  (評価例12:S,O含有皮膜の分析)
 以下、必要に応じて、各実施例の非水電解質二次電池における負極の表面に形成されているS,O含有皮膜を各実施例の負極S,O含有皮膜と略し、各比較例の非水電解質二次電池における負極の表面に形成されている皮膜を各比較例の負極皮膜と略する。
 また、必要に応じて、各実施例の非水電解質二次電池における正極の表面に形成されている皮膜を各実施例の正極S,O含有皮膜と略し、各比較例の非水電解質二次電池における正極の表面に形成されている皮膜を各比較例の正極皮膜と略する。
(Evaluation Example 12: Analysis of S, O-containing film)
Hereinafter, as necessary, the S, O-containing coating formed on the surface of the negative electrode in the non-aqueous electrolyte secondary battery of each example is abbreviated as the negative S, O-containing coating of each example, The film formed on the surface of the negative electrode in the water electrolyte secondary battery is abbreviated as the negative electrode film of each comparative example.
Further, as necessary, the film formed on the surface of the positive electrode in the non-aqueous electrolyte secondary battery of each example is abbreviated as the positive electrode S, O-containing film of each example, and the non-aqueous electrolyte secondary of each comparative example. The film formed on the surface of the positive electrode in the battery is abbreviated as the positive electrode film of each comparative example.
(負極S,O含有皮膜および負極皮膜の分析)
 実施例1-1、実施例1-2および比較例1-1の非水電解質二次電池について、100サイクル充放電を繰り返した後に、電圧3.0Vの放電状態でX線光電子分光分析(X-ray Photoelectron Spectroscopy、XPS)によりS,O含有皮膜または皮膜表面の分析を行った。前処理としては以下の処理を行った。先ず、非水電解質二次電池を解体して負極を取出し、この負極を洗浄および乾燥して、分析対象となる負極を得た。洗浄は、DMC(ジメチルカーボネート)を用いて3回行った。また、セルの解体から分析対象としての負極を分析装置に搬送するまでの全ての工程を、Arガス雰囲気下で、負極を大気に触れさせることなく行った。以下の前処理を実施例1-1、実施例1-2および比較例1-1の各非水電解質二次電池について行い、得られた負極検体をXPS分析した。装置としては、アルバックファイ社 PHI5000 VersaProbeIIを用いた。X線源は単色AlKα線(15kV、10mA)であった。XPSにより測定された実施例1-1、実施例1-2の負極S,O含有皮膜および比較例1-1の負極皮膜の分析結果を図37~図41に示す。具体的には、図37は炭素元素についての分析結果であり、図38はフッ素元素についての分析結果であり、図39は窒素元素についての分析結果であり、図40は酸素元素についての分析結果であり、図41は硫黄元素についての分析結果である。
(Analysis of negative electrode S, O-containing film and negative electrode film)
For the nonaqueous electrolyte secondary batteries of Example 1-1, Example 1-2, and Comparative Example 1-1, X-ray photoelectron spectroscopy analysis (X The analysis of the S, O-containing film or the film surface was performed by ray Photoelectron Spectroscopy (XPS). The following processing was performed as preprocessing. First, the nonaqueous electrolyte secondary battery was disassembled and the negative electrode was taken out. The negative electrode was washed and dried to obtain a negative electrode to be analyzed. Washing was performed 3 times using DMC (dimethyl carbonate). In addition, all steps from disassembling the cell to conveying the negative electrode as the analysis target to the analyzer were performed in an Ar gas atmosphere without exposing the negative electrode to the atmosphere. The following pretreatment was performed on each of the nonaqueous electrolyte secondary batteries of Example 1-1, Example 1-2, and Comparative Example 1-1, and the obtained negative electrode specimen was subjected to XPS analysis. As the apparatus, ULVAC-PHI PHI5000 VersaProbeII was used. The X-ray source was monochromatic AlKα radiation (15 kV, 10 mA). The analysis results of the negative electrode S, O-containing coatings of Example 1-1 and Example 1-2 and the negative electrode coating of Comparative Example 1-1 measured by XPS are shown in FIGS. Specifically, FIG. 37 shows the analysis result for carbon element, FIG. 38 shows the analysis result for fluorine element, FIG. 39 shows the analysis result for nitrogen element, and FIG. 40 shows the analysis result for oxygen element. FIG. 41 shows the analysis results for the elemental sulfur.
 実施例1-1の非水電解質二次電池における電解液、および実施例1-2の非水電解質二次電池における電解液は、塩に硫黄元素(S)、酸素元素および窒素元素(N)を含む。これに対して比較例1-1の非水電解質二次電池における電解液は、塩にこれらを含まない。さらに、実施例1-1、実施例1-2および比較例1-1の非水電解質二次電池における電解液は、いずれも、塩にフッ素元素(F)炭素元素(C)および酸素元素(O)を含む。 The electrolyte in the non-aqueous electrolyte secondary battery of Example 1-1 and the electrolyte in the non-aqueous electrolyte secondary battery of Example 1-2 were salted with sulfur element (S), oxygen element, and nitrogen element (N). including. In contrast, the electrolyte in the nonaqueous electrolyte secondary battery of Comparative Example 1-1 does not contain these in the salt. Furthermore, the electrolyte solutions in the nonaqueous electrolyte secondary batteries of Example 1-1, Example 1-2, and Comparative Example 1-1 were all made of salt with fluorine element (F) carbon element (C) and oxygen element ( O).
 図37~図41に示すように、実施例1-1の負極S,O含有皮膜および実施例1-2の負極S,O含有皮膜を分析した結果、Sの存在を示すピーク(図41)およびNの存在を示すピーク(図39)が観察された。つまり、実施例1-1の負極S,O含有皮膜および実施例1-2の負極S,O含有皮膜はSおよびNを含んでいた。しかし、比較例1-1の負極皮膜の分析結果においてはこれらのピークは確認されなかった。つまり、比較例1-1の負極皮膜はSおよびNの何れについても、検出限界以上の量を含んでいなかった。なお、F、C、およびOの存在を示すピークは、実施例1-1、実施例1-2の負極S,O含有皮膜および比較例1-1の負極皮膜の分析結果全てにおいて観察された。つまり、実施例1-1、実施例1-2の負極S,O含有皮膜および比較例1-1の負極皮膜は何れもF、C、およびOを含んでいた。 As shown in FIGS. 37 to 41, as a result of analyzing the negative electrode S, O-containing film of Example 1-1 and the negative electrode S, O-containing film of Example 1-2, a peak indicating the presence of S (FIG. 41) And a peak indicating the presence of N (FIG. 39) was observed. That is, the negative electrode S, O-containing film of Example 1-1 and the negative electrode S, O-containing film of Example 1-2 contained S and N. However, these peaks were not confirmed in the analysis result of the negative electrode film of Comparative Example 1-1. That is, the negative electrode film of Comparative Example 1-1 did not contain an amount exceeding the detection limit for both S and N. It should be noted that peaks indicating the presence of F, C, and O were observed in all the analysis results of the negative electrode S, O-containing film of Example 1-1 and Example 1-2 and the negative electrode film of Comparative Example 1-1. . That is, the negative electrode S, O-containing film of Example 1-1 and Example 1-2 and the negative electrode film of Comparative Example 1-1 all contained F, C, and O.
 これらの元素は何れも電解液に由来する成分である。特にS、OおよびFは電解液の金属塩に含まれる成分であり、具体的には金属塩のアニオンの化学構造に含まれる成分である。したがって、これらの結果から、各負極S,O含有皮膜および負極皮膜には金属塩(つまり支持塩)のアニオンの化学構造に由来する成分が含まれることがわかる。 These elements are all components derived from the electrolytic solution. In particular, S, O and F are components contained in the metal salt of the electrolytic solution, specifically, components contained in the chemical structure of the anion of the metal salt. Therefore, it can be seen from these results that each of the negative electrode S, O-containing film and the negative electrode film contains a component derived from the chemical structure of the anion of the metal salt (that is, the supporting salt).
 図41に示した硫黄元素(S)の分析結果について、更に詳細に解析した。実施例1-1および実施例1-2の分析結果について、ガウス/ローレンツ混合関数を用いてピーク分離を行った。実施例1-1の解析結果を図42に示し、実施例1-2の解析結果を図43に示す。 The analysis result of elemental sulfur (S) shown in FIG. 41 was analyzed in more detail. For the analysis results of Example 1-1 and Example 1-2, peak separation was performed using a Gauss / Lorentz mixture function. The analysis result of Example 1-1 is shown in FIG. 42, and the analysis result of Example 1-2 is shown in FIG.
 図42および図43に示すように、実施例1-1および1-2の負極S,O含有皮膜を分析した結果、165~175eV付近に比較的大きなピーク(波形)が観察された。そして、図42および図43に示すように、この170eV付近のピーク(波形)は、4つのピークに分離された。そのうちの一つはSO(S=O構造)の存在を示す170eV付近のピークである。この結果から、本発明の非水電解質二次電池において負極表面に形成されているS,O含有皮膜はS=O構造を有するといえる。そして、この結果と上記のXPS分析結果とを考慮すると、S,O含有皮膜のS=O構造に含まれるSは金属塩すなわち支持塩のアニオンの化学構造に含まれるSだと推測される。 As shown in FIGS. 42 and 43, as a result of analyzing the negative electrode S, O-containing films of Examples 1-1 and 1-2, relatively large peaks (waveforms) were observed in the vicinity of 165 to 175 eV. 42 and 43, the peak (waveform) near 170 eV was separated into four peaks. One of them is a peak around 170 eV indicating the presence of SO 2 (S═O structure). From this result, it can be said that the S, O-containing film formed on the negative electrode surface in the nonaqueous electrolyte secondary battery of the present invention has an S = O structure. In consideration of this result and the above XPS analysis result, it is presumed that S contained in the S═O structure of the S, O-containing coating is S contained in the chemical structure of the metal salt, that is, the anion of the supporting salt.
(負極S,O含有皮膜のS元素比率)
 上記した負極S,O含有皮膜のXPS分析結果を基に、実施例1-1および実施例1-2の負極S,O含有皮膜および比較例1-1の負極皮膜における放電時のS元素の比率を算出した。具体的には、各々の負極S,O含有皮膜および負極皮膜につき、S、N、F、C、Oのピーク強度の総和を100%としたときのSの元素比を算出した。結果を表12に示す。
(S element ratio of negative electrode S, O-containing coating)
Based on the XPS analysis results of the negative electrode S and O-containing coating described above, the S element during discharge in the negative electrode S and O-containing coating of Example 1-1 and Example 1-2 and the negative electrode coating of Comparative Example 1-1 The ratio was calculated. Specifically, for each negative electrode S, O-containing film and negative electrode film, the element ratio of S was calculated when the sum of the peak intensities of S, N, F, C, and O was 100%. The results are shown in Table 12.
Figure JPOXMLDOC01-appb-T000012
Figure JPOXMLDOC01-appb-T000012
 上記したように比較例1-1の負極皮膜は検出限界以上のSを含んでいなかったが、実施例1-1の負極S,O含有皮膜および実施例1-2の負極S,O含有皮膜からはSが検出された。また、実施例1-1の負極S,O含有皮膜は実施例1-2の負極S,O含有皮膜に比べて多くのSを含んでいた。なお、比較例1-1の負極S,O含有皮膜からSが検出されなかったことから、各実施例の負極S,O含有皮膜に含まれるSは正極活物質に含まれる不可避不純物やその他の添加物に由来するものではなく、電解液中の金属塩に由来するものであるといえる。 As described above, the negative electrode film of Comparative Example 1-1 did not contain S exceeding the detection limit, but the negative electrode S, O-containing film of Example 1-1 and the negative electrode S, O of Example 1-2 were contained. S was detected from the film. Further, the negative electrode S, O-containing film of Example 1-1 contained more S than the negative electrode S, O-containing film of Example 1-2. Since S was not detected from the negative electrode S, O-containing film of Comparative Example 1-1, S contained in the negative electrode S, O-containing film of each example was an unavoidable impurity contained in the positive electrode active material or other It can be said that it is not derived from the additive but derived from the metal salt in the electrolytic solution.
 また、実施例1-1の負極S,O含有皮膜におけるS元素比率が10.4原子%であり、実施例1-2の負極S,O含有皮膜におけるS元素比率が3.7原子%であることから、本発明の非水電解質二次電池において、負極S,O含有皮膜におけるS元素比率は2.0原子%以上であり、好ましくは2.5原子%以上であり、より好ましくは3.0原子%以上であり、さらに好ましくは3.5原子%以上である。なお、Sの元素比率(原子%)とは、上述したようにS、N、F、C、Oのピーク強度の総和を100%としたときのSのピーク強度比を指す。Sの元素比率の上限値は特に定めないが、強いて言うとすれば、25原子%以下であるのが良い。 The S element ratio in the negative electrode S, O-containing film of Example 1-1 was 10.4 atomic%, and the S element ratio in the negative electrode S, O-containing film in Example 1-2 was 3.7 atomic%. Therefore, in the nonaqueous electrolyte secondary battery of the present invention, the S element ratio in the negative electrode S, O-containing coating is 2.0 atomic% or more, preferably 2.5 atomic% or more, more preferably 3 It is 0.0 atomic% or more, and more preferably 3.5 atomic% or more. The elemental ratio (atomic%) of S indicates the peak intensity ratio of S when the sum of the peak intensities of S, N, F, C, and O is 100% as described above. The upper limit value of the element ratio of S is not particularly defined, but to be strong, it should be 25 atomic% or less.
(負極S,O含有皮膜の厚さ)
 実施例1-1の非水電解質二次電池について、100サイクル充放電を繰り返した後に電圧3.0Vの放電状態にしたもの、および、100サイクル充放電を繰り返した後に電圧4.1Vの充電状態にしたものを準備し、上記のXPS分析の前処理と同様の方法で分析対象となる負極検体を得た。得られた負極検体をFIB(集束イオンビーム:Focused Ion Beam)加工することにより、厚み100nm程度のSTEM分析用検体を得た。なお、FIB加工の前処理として、負極にはPtを蒸着した。以上の工程は負極を大気に触れさせることなくおこなった。
(Thickness of negative electrode S, O-containing film)
Regarding the non-aqueous electrolyte secondary battery of Example 1-1, a state in which a voltage of 3.0 V was discharged after repeating 100 cycles of charge and discharge, and a state of charge of 4.1 V after repeating 100 cycles of charge and discharge A negative electrode sample to be analyzed was obtained by the same method as the pretreatment for XPS analysis described above. The obtained negative electrode specimen was processed by FIB (Focused Ion Beam) to obtain a specimen for STEM analysis having a thickness of about 100 nm. In addition, Pt was vapor-deposited on the negative electrode as a pretreatment for FIB processing. The above steps were performed without exposing the negative electrode to the atmosphere.
 各STEM分析用検体をEDX(エネルギ分散型X線分析:Energy Dispersive X-ray spectroscopy)装置が付属したSTEM(走査透過電子顕微鏡:Scanning Transmission Electron Microscope)により分析した。結果を図44~図47に示す。このうち図44はBF(明視野:Bright-field)-STEM像であり、図45~図47は、図44と同じ観察領域のSETM-EDXによる元素分布像である。さらに、図45はCについての分析結果であり、図46はOについての分析結果であり、図47はSについての分析結果である。なお、図45~図47は、放電状態の非水電解質二次電池における負極の分析結果である。 Each STEM analysis specimen was analyzed by STEM (Scanning Transmission Electron Microscope) with an EDX (Energy Dispersive X-ray spectroscopy) apparatus. The results are shown in FIGS. Among these, FIG. 44 is a BF (Bright-field) -STEM image, and FIGS. 45 to 47 are element distribution images by SETM-EDX in the same observation region as FIG. 45 shows the analysis result for C, FIG. 46 shows the analysis result for O, and FIG. 47 shows the analysis result for S. 45 to 47 show analysis results of the negative electrode in the discharged nonaqueous electrolyte secondary battery.
 図44に示すように、STEM像の左上部には黒色の部分が存在する。この黒色の部分は、FIB加工の前処理で蒸着されたPtに由来する。各STEM像において、このPt由来の部分(Pt部と呼ぶ)よりも上側にある部分は、Pt蒸着後に汚染された部分とみなし得る。したがって、図45~図47においては、Pt部よりも下側にある部分についてのみ検討した。 44. As shown in FIG. 44, a black portion exists in the upper left part of the STEM image. This black part is derived from Pt deposited in the pretreatment of FIB processing. In each STEM image, a portion above the Pt-derived portion (referred to as a Pt portion) can be regarded as a contaminated portion after Pt deposition. Therefore, in FIGS. 45 to 47, only the portion below the Pt portion was examined.
 図45に示すように、Pt部よりも下側において、Cは層状をなしていた。これは、負極活物質たる黒鉛の層状構造だと考えられる。図46において、Oは黒鉛の外周および層間に相当する部分にある。図47においてもまた、Sは黒鉛の外周および層間に相当する部分にある。これらの結果から、S=O構造等のSおよびOを含有する負極S,O含有皮膜は、黒鉛の表面および層間に形成されていると推測される。 As shown in FIG. 45, C was layered below the Pt portion. This is considered to be a layered structure of graphite as a negative electrode active material. In FIG. 46, O exists in the part corresponding to the outer periphery and interlayer of graphite. Also in FIG. 47, S exists in the part corresponding to the outer periphery and interlayer of graphite. From these results, it is surmised that the negative electrode S, O-containing film containing S and O, such as the S═O structure, is formed between the surface and the interlayer of graphite.
 黒鉛の表面に形成されている負極S,O含有皮膜を無作為に10箇所選び、負極S,O含有皮膜の厚さを測定し、測定値の平均値を算出した。充電状態の非水電解質二次電池における負極についても同様に分析し、各分析結果を基に、黒鉛の表面に形成されている負極S,O含有皮膜の厚さの平均値を算出した。結果を表13に示す。 Ten negative electrode S, O-containing films formed on the surface of graphite were randomly selected, the thickness of the negative electrode S, O-containing film was measured, and the average value of the measured values was calculated. The negative electrode in the charged nonaqueous electrolyte secondary battery was analyzed in the same manner, and the average value of the thicknesses of the negative electrode S and O-containing coating formed on the surface of the graphite was calculated based on each analysis result. The results are shown in Table 13.
Figure JPOXMLDOC01-appb-T000013
Figure JPOXMLDOC01-appb-T000013
 表13に示すように、負極S,O含有皮膜の厚みは充電後に増加している。この結果から、負極S,O含有皮膜には充放電に対して安定して存在する定着部と、充放電に伴って増減する吸着部が存在すると推測される。そして、吸着部が存在することで、負極S,O含有皮膜は充放電に際して厚さが増減したと推測される。 As shown in Table 13, the thickness of the negative electrode S, O-containing film increases after charging. From this result, it is presumed that the negative electrode S, O-containing film has a fixing portion that stably exists with respect to charging and discharging and an adsorption portion that increases and decreases with charging and discharging. And it is estimated that the thickness of the negative electrode S, O-containing film increased or decreased during charging / discharging due to the presence of the adsorbing portion.
 (正極皮膜の分析)
 実施例1-1の非水電解質二次電池について、3サイクル充放電を繰り返した後に電圧3.0Vの放電状態にしたもの、3サイクル充放電を繰り返した後に電圧4.1Vの充電状態にしたもの、100サイクル充放電を繰り返した後に電圧3.0Vの放電状態にしたもの、100サイクル充放電を繰り返した後に電圧4.1Vの充電状態にしたもの、の4つを準備した。4つの実施例1-1の非水電解質二次電池について、それぞれ上述したのと同様の方法を用いて、分析対象となる正極を得た。そして得られた各正極をXPS分析した。結果を図48および図49に示す。なお、図48は酸素元素についての分析結果であり、図49は硫黄元素についての分析結果である。
(Analysis of positive electrode film)
Regarding the nonaqueous electrolyte secondary battery of Example 1-1, the battery was discharged in a voltage of 3.0 V after repeating three cycles of charge and discharge, and was charged in a voltage of 4.1 V after repeating three cycles of charge and discharge. Four were prepared: one that was charged at a voltage of 3.0 V after 100 cycles of charge and discharge, and one that was charged at a voltage of 4.1 V after being charged and discharged for 100 cycles. Using the same method as described above for each of the four nonaqueous electrolyte secondary batteries of Example 1-1, positive electrodes to be analyzed were obtained. Then, each obtained positive electrode was analyzed by XPS. The results are shown in FIGS. 48 and 49. FIG. 48 shows the analysis results for the oxygen element, and FIG. 49 shows the analysis results for the sulfur element.
 図48および図49に示すように、実施例1-1の正極S,O含有皮膜もまた、SおよびOを含むことがわかる。また、図49には170eV付近のピークが認められるため、実施例1-1の正極S,O含有皮膜もまた実施例1-1の負極S,O含有皮膜と同様に本発明の電解液に由来するS=O構造を有することがわかる。 48 and 49, it can be seen that the positive electrode S, O-containing film of Example 1-1 also contains S and O. In addition, since a peak around 170 eV is recognized in FIG. 49, the positive electrode S, O-containing film of Example 1-1 is also applied to the electrolyte solution of the present invention in the same manner as the negative electrode S, O-containing film of Example 1-1. It can be seen that it has a derived S═O structure.
 ところで、図48に示すように、529eV付近に存在するピークの高さはサイクル経過後に減少している。このピークは正極活物質に由来するOの存在を示すものと考えられ、具体的には、XPS分析において正極活物質中のO原子で励起された光電子がS,O含有皮膜を通過して検出されたものと考えられる。このピークがサイクル経過後に減少したことから、正極表面に形成されたS,O含有皮膜の厚さはサイクル経過に伴って増大したと考えられる。 By the way, as shown in FIG. 48, the height of the peak existing in the vicinity of 529 eV decreases after the cycle. This peak is considered to indicate the presence of O derived from the positive electrode active material. Specifically, in XPS analysis, photoelectrons excited by O atoms in the positive electrode active material pass through the S, O-containing coating and are detected. It is thought that it was done. Since this peak decreased after the cycle, it is considered that the thickness of the S, O-containing film formed on the positive electrode surface increased with the cycle.
 また、図48および図49に示すように、正極S,O含有皮膜中のOおよびSは放電時に増加し充電時に減少した。この結果から、OおよびSは充放電に伴って正極S,O含有皮膜を出入りすると考えられる。そしてこのことから、充放電に際して正極S,O含有皮膜中のSやOの濃度が増減しているか、または、負極S,O含有皮膜と同様に正極S,O含有皮膜においても吸着部の存在により厚さが増減すると推測される。 Further, as shown in FIGS. 48 and 49, O and S in the positive electrode S, O-containing film increased during discharging and decreased during charging. From this result, it is considered that O and S enter and leave the positive electrode S and O-containing film with charge and discharge. From this fact, the concentration of S and O in the positive electrode S and O-containing coating is increased or decreased during charging or discharging, or the presence of an adsorbing portion in the positive electrode S and O-containing coating as well as the negative electrode S and O-containing coating. It is estimated that the thickness increases or decreases.
 さらに、実施例1-4の非水電解質二次電池についても正極S,O含有皮膜および負極S,O含有皮膜をXPS分析した。 Furthermore, for the nonaqueous electrolyte secondary battery of Example 1-4, the positive electrode S, O-containing coating and the negative electrode S, O-containing coating were analyzed by XPS.
 実施例1-4の非水電解質二次電池を、25℃、使用電圧範囲3.0V~4.1Vとし、レート1CでCC充放電を500サイクル繰り返した。500サイクル後、3.0Vの放電状態、および、4.0Vの充電状態で正極S,O含有皮膜のXPSスペクトルを測定した。また、サイクル試験前(つまり初回充放電後)における3.0Vの放電状態の負極S,O含有皮膜、および、500サイクル後における3.0Vの放電状態の負極S,O含有皮膜について、XPSによる元素分析をおこない、当該負極S,O含有皮膜に含まれるS元素比率を算出した。XPSにより測定された実施例1-4の正極S,O含有皮膜の分析結果を図50および図51に示す。具体的には、図50は硫黄元素についての分析結果であり、図51は酸素元素についての分析結果である。また、XPSにより測定された負極皮膜のS元素比率(原子%)を表14に示す。なお、S元素比率は、上記の「負極S,O含有皮膜のS元素比率」の項と同様に算出した。 The nonaqueous electrolyte secondary battery of Example 1-4 was set to 25 ° C., operating voltage range 3.0V to 4.1V, and CC charge / discharge was repeated 500 cycles at a rate of 1C. After 500 cycles, the XPS spectrum of the positive electrode S, O-containing film was measured in a discharge state of 3.0 V and a charge state of 4.0 V. Further, the negative electrode S, O-containing coating in the 3.0V discharge state before the cycle test (that is, after the first charge / discharge) and the negative electrode S, O-containing coating in the 3.0V discharge state after 500 cycles are measured by XPS. Elemental analysis was performed, and the S element ratio contained in the negative electrode S, O-containing film was calculated. The analysis results of the positive electrode S, O-containing film of Example 1-4 measured by XPS are shown in FIGS. Specifically, FIG. 50 shows the analysis result for sulfur element, and FIG. 51 shows the analysis result for oxygen element. Table 14 shows the S element ratio (atomic%) of the negative electrode film measured by XPS. The S element ratio was calculated in the same manner as the above-mentioned item “S element ratio of negative electrode S, O-containing film”.
 図50および図51に示すように、実施例1-4の非水電解質二次電池における正極S,O含有皮膜からもまた、Sの存在を示すピークおよびOの存在を示すピークが検出された。また、SのピークおよびOのピークが何れも放電時に増大し充電時に減少していた。この結果からも、正極S,O含有皮膜がS=O構造を有し、正極S,O含有皮膜中のOおよびSは充放電に伴って正極S,O含有皮膜を出入りすることが裏付けられる。 As shown in FIGS. 50 and 51, a peak indicating the presence of S and a peak indicating the presence of O were also detected from the positive electrode S, O-containing film in the nonaqueous electrolyte secondary battery of Example 1-4. . In addition, both the S peak and the O peak increased during discharging and decreased during charging. This result also confirms that the positive electrode S, O-containing film has an S = O structure, and O and S in the positive electrode S, O-containing film enter and exit the positive electrode S, O-containing film with charge and discharge. .
Figure JPOXMLDOC01-appb-T000014
Figure JPOXMLDOC01-appb-T000014
 また、表14に示すように、実施例1-4の負極S,O含有皮膜は、初回充放電後にも、500サイクル経過後にも、2.0原子%以上のSを含んでいた。この結果から、本発明の非水電解質二次電池における負極S,O含有皮膜は、サイクル経過前であってもサイクル経過後であっても2.0原子%以上のSを含むことがわかる。 As shown in Table 14, the negative electrode S, O-containing film of Example 1-4 contained 2.0 atomic% or more of S even after the first charge / discharge and after 500 cycles. From this result, it can be seen that the negative electrode S, O-containing film in the nonaqueous electrolyte secondary battery of the present invention contains 2.0 atomic% or more of S before or after the cycle.
 実施例1-4~実施例1-7および比較例1-2、比較例1-3の非水電解質二次電池について、60℃で1週間貯蔵する高温貯蔵試験を行い、当該高温貯蔵試験後の各実施例の正極S,O含有皮膜および負極S,O含有皮膜、ならびに、各比較例の正極皮膜および負極皮膜を分析した。高温貯蔵試験開始前に、3.0Vから4.1Vにまでレート0.33CでCC-CV充電した。このときの充電容量を基準(SOC100)とし、当該基準に対して20%分をCC放電してSOC80に調整した後、高温貯蔵試験を開始した。高温貯蔵試験後に1Cで3.0VまでCC-CV放電した。そして、放電後の正極S,O含有皮膜および負極S,O含有皮膜ならびに正極皮膜および負極皮膜のXPSスペクトルを測定した。XPSにより測定された実施例1-4~実施例1-7の正極S,O含有皮膜、ならびに、比較例1-2および比較例1-3の正極皮膜の分析結果を図52~図55に示す。また、XPSにより測定された実施例1-4~実施例1-7の負極S,O含有皮膜、ならびに、比較例1-2および比較例1-3の負極皮膜の分析結果を図56~図52に示す。 The non-aqueous electrolyte secondary batteries of Examples 1-4 to 1-7 and Comparative Examples 1-2 and 1-3 were subjected to a high-temperature storage test that was stored at 60 ° C. for one week. The positive electrode S, O-containing film and negative electrode S, O-containing film of each of the examples, and the positive electrode film and negative electrode film of each comparative example were analyzed. Before starting the high temperature storage test, CC-CV charge was performed at a rate of 0.33 C from 3.0 V to 4.1 V. The charge capacity at this time was set as a standard (SOC100), 20% of the standard was CC discharged and adjusted to SOC80, and then a high-temperature storage test was started. After the high temperature storage test, CC-CV discharge was performed to 3.0V at 1C. And the XPS spectrum of the positive electrode S, O containing film | membrane and negative electrode S, O containing film | membrane after a discharge and a positive electrode film | membrane and a negative electrode film | membrane was measured. The analysis results of the positive electrode S, O-containing films of Examples 1-4 to 1-7 and the positive electrode films of Comparative Examples 1-2 and 1-3 measured by XPS are shown in FIGS. Show. Also, the analysis results of the negative electrode S, O-containing coatings of Examples 1-4 to 1-7 and the negative coatings of Comparative Examples 1-2 and 1-3 measured by XPS are shown in FIGS. 52.
 具体的には、図52は実施例1-4、実施例1-5の正極S,O含有皮膜および比較例1-2の正極皮膜の硫黄元素についての分析結果である。図53は実施例1-6、実施例1-7の正極S,O含有皮膜および比較例1-3の正極皮膜の硫黄元素についての分析結果である。図54は実施例1-4、実施例1-5の正極S,O含有皮膜および比較例1-2の正極皮膜の酸素元素についての分析結果である。図55は実施例1-6、実施例1-7の正極S,O含有皮膜および比較例1-3の正極皮膜の酸素元素についての分析結果である。また、図56は実施例1-4、実施例1-5の負極S,O含有皮膜および比較例1-2の負極皮膜の硫黄元素についての分析結果である。図57は実施例1-6、実施例1-7の負極S,O含有皮膜および比較例1-3の負極皮膜の硫黄元素についての分析結果である。図58は実施例1-4、実施例1-5の負極S,O含有皮膜および比較例1-2の負極皮膜の酸素元素についての分析結果である。図59は実施例1-6、実施例1-7の負極S,O含有皮膜および比較例1-3の負極皮膜の酸素元素についての分析結果である。 Specifically, FIG. 52 shows the analysis results for the elemental sulfur in the positive electrode S, O-containing coatings of Examples 1-4 and 1-5 and the positive electrode coating of Comparative Example 1-2. FIG. 53 shows the analysis results for the elemental sulfur in the positive electrode S, O-containing coatings of Examples 1-6 and 1-7 and the positive electrode coating of Comparative Example 1-3. FIG. 54 shows analysis results of oxygen elements in the positive electrode S, O-containing coatings of Examples 1-4 and 1-5 and the positive electrode coating of Comparative Example 1-2. FIG. 55 shows the analysis results of oxygen elements in the positive electrode S, O-containing films of Examples 1-6 and 1-7 and the positive electrode film of Comparative Example 1-3. FIG. 56 shows the analysis results of the elemental sulfur in the negative electrode S, O-containing coatings of Examples 1-4 and 1-5 and the negative electrode coating of Comparative Example 1-2. FIG. 57 shows the analysis results of the elemental sulfur in the negative electrode S, O-containing coatings of Examples 1-6 and 1-7 and the negative electrode coating of Comparative Example 1-3. FIG. 58 shows the results of analysis of oxygen elements in the negative electrode S, O-containing films of Examples 1-4 and 1-5 and the negative electrode film of Comparative Example 1-2. FIG. 59 shows analysis results of oxygen elements in the negative electrode S, O-containing coatings of Examples 1-6 and 1-7 and the negative electrode coating of Comparative Example 1-3.
 図52および図53に示すように、従来の電解液を用いた比較例1-2および比較例1-3の非水電解質二次電池は正極皮膜にSを含まないのに対して、本発明の電解液を用いた実施例1-4~実施例1-7の非水電解質二次電池は正極S,O含有皮膜にSを含んでいた。また、図54および図55に示すように、実施例1-4~実施例1-7の非水電解質二次電池は何れも正極S,O含有皮膜にOを含んでいた。さらに、図52および図53に示すように、実施例1-4~実施例1-7の非水電解質二次電池における正極S,O含有皮膜からは、何れも、SO(S=O構造)の存在を示す170eV付近のピークが検出された。これらの結果から、本発明の非水電解質二次電池においては、電解液用の有機溶媒としてANを用いた場合にも、DMCを用いた場合にも、SとOとを含む安定した正極S,O含有皮膜が形成されることがわかる。また、この正極S,O含有皮膜は負極結着剤の種類に影響されないことから、正極S,O含有皮膜中のOはCMCに由来するものではないと考えられる。さらに、図54および図55に示すように、電解液用の有機溶媒としてDMCを用いる場合には、530eV付近に、正極活物質由来のOピークが検出された。このため、電解液用の有機溶媒としてDMCを用いる場合には、ANを用いる場合に比べて正極S,O含有皮膜の厚さが薄くなると考えられる。 As shown in FIGS. 52 and 53, the nonaqueous electrolyte secondary batteries of Comparative Example 1-2 and Comparative Example 1-3 using the conventional electrolytic solution do not contain S in the positive electrode film. In the nonaqueous electrolyte secondary batteries of Examples 1-4 to 1-7 using the electrolyte solution, the positive electrode S and O-containing film contained S. As shown in FIGS. 54 and 55, the nonaqueous electrolyte secondary batteries of Examples 1-4 to 1-7 all contained O in the positive electrode S, O-containing film. Further, as shown in FIGS. 52 and 53, the positive electrode S, O-containing coatings in the nonaqueous electrolyte secondary batteries of Examples 1-4 to 1-7 all have SO 2 (S═O structure). A peak around 170 eV indicating the presence of) was detected. From these results, in the non-aqueous electrolyte secondary battery of the present invention, a stable positive electrode S containing S and O is used both when AN is used as the organic solvent for the electrolytic solution and when DMC is used. It can be seen that an O-containing film is formed. Moreover, since this positive electrode S, O containing film is not influenced by the kind of negative electrode binder, it is thought that O in the positive electrode S, O containing film does not originate in CMC. Further, as shown in FIGS. 54 and 55, when DMC was used as the organic solvent for the electrolytic solution, an O peak derived from the positive electrode active material was detected in the vicinity of 530 eV. For this reason, when DMC is used as the organic solvent for the electrolytic solution, it is considered that the thickness of the positive electrode S, O-containing film is thinner than when AN is used.
 同様に、図56~図59から、実施例1-4~実施例1-7の非水電解質二次電池は負極S,O含有皮膜にもSおよびOを含み、これらはS=O構造をなしかつ電解液に由来することがわかる。そしてこの負極S,O含有皮膜は、電解液用の有機溶媒としてANを用いた場合にもDMCを用いた場合にも形成されることがわかる。 Similarly, from FIG. 56 to FIG. 59, the nonaqueous electrolyte secondary batteries of Examples 1-4 to 1-7 also contain S and O in the negative electrode S and O-containing films, and these have an S═O structure. None and derived from the electrolyte. And it turns out that this negative electrode S and O containing film | membrane is formed even when AN is used as an organic solvent for electrolyte solutions, and also when DMC is used.
 実施例1-4、実施例1-5および比較例1-2の非水電解質二次電池について、上記の高温貯蔵試験および放電後の各負極S,O含有皮膜ならびに負極皮膜のXPSスペクトルを測定し、実施例1-4、実施例1-5の負極S,O含有皮膜および比較例1-2の負極皮膜における放電時のS元素の比率を算出した。具体的には、各々の負極S,O含有皮膜または負極皮膜につき、S、N、F、C、Oのピーク強度の総和を100%としたときのSの元素比を算出した。結果を表15に示す。 For the non-aqueous electrolyte secondary batteries of Example 1-4, Example 1-5, and Comparative Example 1-2, the XPS spectra of the negative electrode S and O-containing films and the negative electrode films after the above high-temperature storage test and discharge were measured. Then, the ratio of the S element at the time of discharge in the negative electrode S, O-containing film of Example 1-4 and Example 1-5 and the negative electrode film of Comparative Example 1-2 was calculated. Specifically, for each negative electrode S, O-containing film or negative electrode film, the element ratio of S was calculated when the sum of the peak intensities of S, N, F, C, and O was 100%. The results are shown in Table 15.
Figure JPOXMLDOC01-appb-T000015
Figure JPOXMLDOC01-appb-T000015
 表15に示すように、比較例1-2の負極皮膜は検出限界以上のSを含んでいなかったが、実施例1-4および実施例1-5の負極S,O含有皮膜からはSが検出された。また、実施例1-5の負極S,O含有皮膜は実施例1-4の負極S,O含有皮膜に比べて多くのSを含んでいた。また、この結果から、高温貯蔵後においても負極S,O含有皮膜におけるS元素比率は2.0原子%以上であることがわかる。 As shown in Table 15, the negative electrode film of Comparative Example 1-2 did not contain S exceeding the detection limit, but from the negative electrode S, O-containing films of Examples 1-4 and 1-5, S Was detected. Further, the negative electrode S, O-containing film of Example 1-5 contained more S than the negative electrode S, O-containing film of Example 1-4. Further, from this result, it is understood that the S element ratio in the negative electrode S, O-containing film is 2.0 atomic% or more even after high temperature storage.
  (評価例13:電池の内部抵抗)
 実施例1-4、実施例1-5、実施例1-8および比較例1-2の非水電解質二次電池を準備し、電池の内部抵抗を評価した。
 実施例1-4、実施例1-5、実施例1-8および比較例1-2の各非水電解質二次電池について、室温、3.0V~4.1V(vs.Li基準)の範囲でCC充放電(つまり定電流充放電)を繰り返した。そして、初回充放電後の交流インピーダンス、および、100サイクル経過後の交流インピーダンスを測定した。得られた複素インピーダンス平面プロットを基に、電解液、負極および正極の反応抵抗を各々解析した。図60に示すように、複素インピーダンス平面プロットには、二つの円弧がみられた。図中左側(つまり複素インピーダンスの実部が小さい側)の円弧を第1円弧と呼ぶ。図中右側の円弧を第2円弧と呼ぶ。第1円弧の大きさを基に負極の反応抵抗を解析し、第2円弧の大きさを基に正極の反応抵抗を解析した。第1円弧に連続する図60中最左側のプロットを基に電解液の抵抗を解析した。解析結果を表16および表17に示す。なお、表16は、初回充放電後の電解液の抵抗(所謂溶液抵抗)、負極の反応抵抗、正極の反応抵抗を示し、表17は100サイクル経過後の各抵抗を示す。
(Evaluation Example 13: Internal resistance of battery)
Nonaqueous electrolyte secondary batteries of Example 1-4, Example 1-5, Example 1-8, and Comparative Example 1-2 were prepared, and the internal resistance of the battery was evaluated.
For each non-aqueous electrolyte secondary battery of Example 1-4, Example 1-5, Example 1-8 and Comparative Example 1-2, room temperature, a range of 3.0 V to 4.1 V (vs. Li standard) Then, CC charge / discharge (that is, constant current charge / discharge) was repeated. Then, the AC impedance after the first charge / discharge and the AC impedance after 100 cycles were measured. Based on the obtained complex impedance plane plot, the reaction resistances of the electrolytic solution, the negative electrode, and the positive electrode were each analyzed. As shown in FIG. 60, two circular arcs were seen in the complex impedance plane plot. The arc on the left side of the figure (that is, the side where the real part of the complex impedance is small) is called the first arc. The arc on the right side in the figure is called the second arc. The reaction resistance of the negative electrode was analyzed based on the size of the first arc, and the reaction resistance of the positive electrode was analyzed based on the size of the second arc. The resistance of the electrolytic solution was analyzed based on the leftmost plot in FIG. 60 continuous with the first arc. The analysis results are shown in Table 16 and Table 17. Table 16 shows the resistance (so-called solution resistance) of the electrolytic solution after the first charge / discharge, the reaction resistance of the negative electrode, and the reaction resistance of the positive electrode, and Table 17 shows the resistance after 100 cycles.
Figure JPOXMLDOC01-appb-T000016
Figure JPOXMLDOC01-appb-T000016
Figure JPOXMLDOC01-appb-T000017
Figure JPOXMLDOC01-appb-T000017
 表16および表17に示すように、各非水電解質二次電池において、100サイクル経過後の負極反応抵抗および正極反応抵抗は、初回充放電後の各抵抗に比べて低下する傾向にある。そして、表17に示す100サイクル経過後では、各実施例の非水電解質二次電池の負極反応抵抗および正極反応抵抗は、比較例1-2の非水電解質二次電池の負極反応抵抗および正極反応抵抗に比べて低い。 As shown in Table 16 and Table 17, in each non-aqueous electrolyte secondary battery, the negative electrode reaction resistance and the positive electrode reaction resistance after 100 cycles tend to be lower than the respective resistances after the first charge / discharge. After 100 cycles shown in Table 17, the negative electrode reaction resistance and the positive electrode reaction resistance of the nonaqueous electrolyte secondary battery of each example were the negative electrode reaction resistance and the positive electrode of the nonaqueous electrolyte secondary battery of Comparative Example 1-2. Low compared to reaction resistance.
 上述したように、実施例1-4、実施例1-5および実施例1-8の非水電解質二次電池は本発明の電解液を用いたものであり、負極および正極の表面には本発明の電解液に由来するS,O含有皮膜が形成されている。これに対して、本発明の電解液を用いていない比較例1-2の非水電解質二次電池においては、負極および正極の表面には当該S,O含有皮膜は形成されていない。そして、表17に示すように、実施例1-4、実施例1-5および実施例1-8の負極反応抵抗および正極反応抵抗は比較例1-2の非水電解質二次電池よりも低い。このことから、各実施例においては、本発明の電解液に由来するS,O含有皮膜の存在により負極反応抵抗および正極反応抵抗が低減したと推察される。 As described above, the nonaqueous electrolyte secondary batteries of Examples 1-4, 1-5, and 1-8 use the electrolyte solution of the present invention. An S, O-containing film derived from the electrolytic solution of the invention is formed. On the other hand, in the non-aqueous electrolyte secondary battery of Comparative Example 1-2 that does not use the electrolytic solution of the present invention, the S and O-containing coating is not formed on the surfaces of the negative electrode and the positive electrode. As shown in Table 17, the negative electrode reaction resistance and the positive electrode reaction resistance of Example 1-4, Example 1-5, and Example 1-8 are lower than those of the nonaqueous electrolyte secondary battery of Comparative Example 1-2. . From this, in each Example, it is guessed that the negative electrode reaction resistance and the positive electrode reaction resistance were reduced by the presence of the S, O-containing film derived from the electrolytic solution of the present invention.
 なお、実施例1-5および比較例1-2の非水電解質二次電池における電解液の溶液抵抗はほぼ同じであり、実施例1-4および実施例1-8の非水電解質二次電池における電解液の溶液抵抗は、実施例1-5および比較例1-2に比べて高い。また、各非水電解質二次電池における各電解液の溶液抵抗は初回充放電後も100サイクル経過後もほぼ同じである。このため、各電解液の耐久劣化は生じていないと考えられ、上記した比較例および実施例において生じた負極反応抵抗および正極反応抵抗の差は、電解液の耐久劣化に関係するものでなく電極自体に生じているものであると考えられる。 The solution resistances of the electrolyte solutions in the nonaqueous electrolyte secondary batteries of Example 1-5 and Comparative Example 1-2 are almost the same, and the nonaqueous electrolyte secondary batteries of Example 1-4 and Example 1-8 The solution resistance of the electrolyte solution in is higher than in Example 1-5 and Comparative Example 1-2. The solution resistance of each electrolyte solution in each non-aqueous electrolyte secondary battery is substantially the same after the first charge / discharge and after 100 cycles. For this reason, it is considered that the durability deterioration of each electrolytic solution does not occur, and the difference between the negative electrode reaction resistance and the positive electrode reaction resistance generated in the comparative examples and examples described above is not related to the durability deterioration of the electrolyte solution but the electrode. It is thought to have occurred in itself.
 非水電解質二次電池の内部抵抗は、電解液の溶液抵抗、負極の反応抵抗および正極の反応抵抗から総合的に判断できる。表16および表17の結果を基にすると、非水電解質二次電池の内部抵抗増大を抑制する観点からは、実施例1-4および実施例1-8の非水電解質二次電池が特に耐久性に優れ、次いで実施例1-5の非水電解質二次電池が耐久性に優れていると言える。 The internal resistance of the non-aqueous electrolyte secondary battery can be comprehensively determined from the solution resistance of the electrolytic solution, the reaction resistance of the negative electrode, and the reaction resistance of the positive electrode. Based on the results of Table 16 and Table 17, the nonaqueous electrolyte secondary batteries of Examples 1-4 and 1-8 are particularly durable from the viewpoint of suppressing the increase in internal resistance of the nonaqueous electrolyte secondary battery. It can be said that the nonaqueous electrolyte secondary battery of Example 1-5 is excellent in durability.
  (評価例14:電池のサイクル耐久性)
 実施例1-4、実施例1-5、実施例1-8および比較例1-2の各非水電解質二次電池について、室温、3.0V~4.1V(vs.Li基準)の範囲でCC充放電を繰り返し、初回充放電時の放電容量、100サイクル時の放電容量、および500サイクル時の放電容量を測定した。そして、初回充放電時の各非水電解質二次電池の容量を100%とし、100サイクル時および500サイクル時の各非水電解質二次電池の容量維持率(%)を算出した。結果を表18に示す。
(Evaluation Example 14: Battery cycle durability)
For each non-aqueous electrolyte secondary battery of Example 1-4, Example 1-5, Example 1-8 and Comparative Example 1-2, room temperature, a range of 3.0 V to 4.1 V (vs. Li standard) The CC charge / discharge was repeated, and the discharge capacity at the first charge / discharge, the discharge capacity at 100 cycles, and the discharge capacity at 500 cycles were measured. And the capacity | capacitance maintenance factor (%) of each nonaqueous electrolyte secondary battery at the time of 100 cycles and 500 cycles was computed by making the capacity | capacitance of each nonaqueous electrolyte secondary battery at the time of initial charge / discharge into 100%. The results are shown in Table 18.
Figure JPOXMLDOC01-appb-T000018
Figure JPOXMLDOC01-appb-T000018
 表18に示すように、実施例1-4、実施例1-5および実施例1-8の非水電解質二次電池は、SEIの材料となるECを含まないにも拘わらず、ECを含む比較例1-2の非水電解質二次電池と同等の容量維持率を示した。これは、各実施例の非水電解質二次電池における正極および負極には、本発明の電解液に由来するS,O含有皮膜が存在するためだと考えられる。そして、実施例1-4の非水電解質二次電池については、特に500サイクル経過時にも極めて高い容量維持率を示し、特に耐久性に優れていた。この結果から、有機溶媒としてDMCを選択する場合には、ANを選択する場合に比べて、より耐久性が向上するといえる。 As shown in Table 18, the nonaqueous electrolyte secondary batteries of Examples 1-4, 1-5, and 1-8 contain EC even though they do not contain EC as a material for SEI. The capacity retention rate equivalent to that of the nonaqueous electrolyte secondary battery of Comparative Example 1-2 was shown. This is thought to be because the S and O-containing coatings derived from the electrolytic solution of the present invention are present on the positive electrode and the negative electrode in the nonaqueous electrolyte secondary battery of each example. The nonaqueous electrolyte secondary battery of Example 1-4 exhibited an extremely high capacity retention rate even after the elapse of 500 cycles, and was particularly excellent in durability. From this result, it can be said that when DMC is selected as the organic solvent, the durability is further improved as compared with the case where AN is selected.
  (評価例15:高温貯蔵試験)
 実施例1-4、実施例1-5および比較例1-2の非水電解質二次電池について、60℃で1週間貯蔵する高温貯蔵試験を行った。高温貯蔵試験開始前に、3.0Vから4.1VにまでCC-CV(定電流定電圧)充電した。このときの充電容量を基準(SOC100)とし、当該基準に対して20%分をCC放電してSOC80に調整した後、高温貯蔵試験を開始した。高温貯蔵試験後に1Cで3.0VまでCC-CV放電した。このときの放電容量と貯蔵前のSOC80容量との比から、次式のように残存容量を算出した。結果を表19に示す。
 残存容量=100×(貯蔵後のCC-CV放電容量)/(貯蔵前のSOC80容量)
(Evaluation Example 15: High temperature storage test)
The non-aqueous electrolyte secondary batteries of Example 1-4, Example 1-5, and Comparative Example 1-2 were subjected to a high-temperature storage test that was stored at 60 ° C. for 1 week. Before starting the high-temperature storage test, CC-CV (constant current constant voltage) charging was performed from 3.0 V to 4.1 V. The charge capacity at this time was set as a standard (SOC100), 20% of the standard was CC discharged and adjusted to SOC80, and then a high-temperature storage test was started. After the high temperature storage test, CC-CV discharge was performed to 3.0V at 1C. From the ratio of the discharge capacity at this time and the SOC 80 capacity before storage, the remaining capacity was calculated as follows. The results are shown in Table 19.
Remaining capacity = 100 × (CC-CV discharge capacity after storage) / (SOC 80 capacity before storage)
Figure JPOXMLDOC01-appb-T000019
Figure JPOXMLDOC01-appb-T000019
 実施例1-4および実施例1-5の非水電解質二次電池の残存容量は、比較例1-2の非水電解質二次電池の残存容量に比べて大きい。この結果から、本発明の電解液に由来し正極および負極に形成されたS,O含有皮膜が、残存容量増大にも寄与するといえる。 The remaining capacity of the nonaqueous electrolyte secondary batteries of Examples 1-4 and 1-5 is larger than the remaining capacity of the nonaqueous electrolyte secondary battery of Comparative Example 1-2. From this result, it can be said that the S, O-containing coating derived from the electrolytic solution of the present invention and formed on the positive electrode and the negative electrode contributes to an increase in the remaining capacity.
  (評価例16:レート容量特性)
 実施例1-1および比較例1-1の非水電解質二次電池のレート容量特性を以下の方法で評価した。各電池の容量は160mAh/gとなるように調整した。評価条件は、各非水電解質二次電池につき、0.1C、0.2C、0.5C、1C、2Cの速度で充電を行った後に放電を行い、それぞれの速度における作用極の容量(放電容量)を測定した。0.1C放電後および1C放電後の放電容量を表20に示す。なお表20に示した放電容量は、正極活物質の質量(g)当りの容量を算出したものである。
(Evaluation Example 16: Rate capacity characteristics)
The rate capacity characteristics of the nonaqueous electrolyte secondary batteries of Example 1-1 and Comparative Example 1-1 were evaluated by the following methods. The capacity of each battery was adjusted to 160 mAh / g. The evaluation condition was that each non-aqueous electrolyte secondary battery was charged at a rate of 0.1 C, 0.2 C, 0.5 C, 1 C, 2 C, and then discharged, and the capacity of the working electrode at each rate (discharge) Capacity). Table 20 shows the discharge capacity after 0.1 C discharge and after 1 C discharge. In addition, the discharge capacity shown in Table 20 is a capacity calculated per mass (g) of the positive electrode active material.
Figure JPOXMLDOC01-appb-T000020
Figure JPOXMLDOC01-appb-T000020
 表20に示すように、放電速度が遅い場合(0.1C)には、実施例1-1の非水電解質二次電池と比較例1-1の非水電解質二次電池との間に放電容量の違いは殆どない。しかし、放電速度が速い場合(1.0C)には、実施例1-1の非水電解質二次電池の放電容量は、比較例1-1の非水電解質二次電池の放電容量に比べて大きい。この結果から、本発明の非水電解質二次電池がレート容量特性に優れることが裏づけられる。これは、上述したように、本発明の非水電解質二次電池における電解液が従来のものとは異なり、本発明の非水電解質二次電池の負極および/または正極に形成されるS,O含有皮膜もまた、従来のものと異なるためだと考えられる。 As shown in Table 20, when the discharge rate is slow (0.1 C), a discharge is caused between the nonaqueous electrolyte secondary battery of Example 1-1 and the nonaqueous electrolyte secondary battery of Comparative Example 1-1. There is almost no difference in capacity. However, when the discharge rate is high (1.0 C), the discharge capacity of the nonaqueous electrolyte secondary battery of Example 1-1 is larger than the discharge capacity of the nonaqueous electrolyte secondary battery of Comparative Example 1-1. large. This result supports that the nonaqueous electrolyte secondary battery of the present invention is excellent in rate capacity characteristics. As described above, this is because the electrolyte in the non-aqueous electrolyte secondary battery of the present invention is different from the conventional one, and S, O formed on the negative electrode and / or the positive electrode of the non-aqueous electrolyte secondary battery of the present invention. It is thought that the contained film is also different from the conventional film.
  (評価例17:0℃、SOC20%での出力特性評価)
 上記の実施例1-1および比較例1-1の非水電解質二次電池の出力特性を評価した。評価条件は、充電状態(SOC)20%、0℃、使用電圧範囲3V-4.2V、容量13.5mAhである。SOC20%、0℃は、例えば、冷蔵室などで使用する場合のように出力特性が出にくい領域である。実施例1-1および比較例1-1の非水電解質二次電池の出力特性の評価は、それぞれ2秒出力と5秒出力についてそれぞれ3回行った。出力特性の評価結果を表21に示した。表21の中の「2秒出力」は、放電開始から2秒後での出力を意味し、「5秒出力」は放電開始から5秒後での出力を意味している。後述の表22~表23においても同様である。
(Evaluation Example 17: Output characteristic evaluation at 0 ° C. and SOC 20%)
The output characteristics of the nonaqueous electrolyte secondary batteries of Example 1-1 and Comparative Example 1-1 were evaluated. The evaluation conditions are a state of charge (SOC) 20%, 0 ° C., a working voltage range 3V-4.2V, and a capacity 13.5 mAh. SOC 20%, 0 ° C. is a region where output characteristics are difficult to be obtained, for example, when used in a refrigerator room. The output characteristics of the nonaqueous electrolyte secondary batteries of Example 1-1 and Comparative Example 1-1 were evaluated three times for each of the 2-second output and 5-second output. Table 21 shows the evaluation results of the output characteristics. In Table 21, “2 seconds output” means an output 2 seconds after the start of discharge, and “5 seconds output” means an output 5 seconds after the start of discharge. The same applies to Tables 22 to 23 described later.
Figure JPOXMLDOC01-appb-T000021
Figure JPOXMLDOC01-appb-T000021
 表21に示すように、実施例1-1の非水電解質二次電池の0℃、SOC20%の出力は、比較例1-1の非水電解質二次電池の出力に比べて、1.2倍~1.3倍高かった。 As shown in Table 21, the output of the nonaqueous electrolyte secondary battery of Example 1-1 at 0 ° C. and SOC 20% was 1.2% compared to the output of the nonaqueous electrolyte secondary battery of Comparative Example 1-1. Double to 1.3 times higher.
  (評価例18:25℃、SOC20%での出力特性評価)
 実施例1-1および比較例1-1のリチウムイオン電池の出力特性を、充電状態(SOC)20%、25℃、使用電圧範囲3V―4.2V、容量13.5mAhの条件で評価した。実施例1-1および比較例1-1の非水電解質二次電池の出力特性の評価は、それぞれ2秒出力と5秒出力についてそれぞれ3回行った。評価結果を表22に示した。
(Evaluation Example 18: Evaluation of output characteristics at 25 ° C. and SOC 20%)
The output characteristics of the lithium ion batteries of Example 1-1 and Comparative Example 1-1 were evaluated under the conditions of the state of charge (SOC) 20%, 25 ° C., operating voltage range 3 V-4.2 V, and capacity 13.5 mAh. The output characteristics of the nonaqueous electrolyte secondary batteries of Example 1-1 and Comparative Example 1-1 were evaluated three times for each of the 2-second output and 5-second output. The evaluation results are shown in Table 22.
Figure JPOXMLDOC01-appb-T000022
Figure JPOXMLDOC01-appb-T000022
 表22に示すように、実施例1-1の非水電解質二次電池の25℃、SOC20%の出力は、比較例1-1の非水電解質二次電池の出力に比べて、1.2倍~1.3倍高かった。 As shown in Table 22, the output of the nonaqueous electrolyte secondary battery of Example 1-1 at 25 ° C. and SOC 20% was 1.2% compared to the output of the nonaqueous electrolyte secondary battery of Comparative Example 1-1. Double to 1.3 times higher.
  (評価例19:出力特性に対する温度の影響)
 また、上記の実施例1-1および比較例1-1の非水電解質二次電池の出力特性に対する、測定時の温度の影響を調べた。0℃と25℃で測定し、いずれの温度下での測定においても、評価条件は、充電状態(SOC)20%、使用電圧範囲3V―4.2V、容量13.5mAhとした。25℃での出力に対する0℃での出力の比率(0℃出力/25℃出力)をもとめた。その結果を表23に示した。
(Evaluation Example 19: Effect of temperature on output characteristics)
In addition, the influence of temperature during measurement on the output characteristics of the nonaqueous electrolyte secondary batteries of Example 1-1 and Comparative Example 1-1 was examined. Measurement was performed at 0 ° C. and 25 ° C., and in any measurement, the evaluation conditions were a state of charge (SOC) of 20%, a working voltage range of 3 V to 4.2 V, and a capacity of 13.5 mAh. The ratio of the output at 0 ° C. to the output at 25 ° C. (0 ° C. output / 25 ° C. output) was determined. The results are shown in Table 23.
Figure JPOXMLDOC01-appb-T000023
Figure JPOXMLDOC01-appb-T000023
 表23に示すように、実施例1-1の非水電解質二次電池は、2秒出力および5秒出力における25℃での出力に対する0℃での出力の比率(0℃出力/25℃出力)が、比較例1-1の非水電解質二次電池と同程度であり、実施例1-1の非水電解質二次電池は、比較例1-1の非水電解質二次電池と同程度には低温での出力低下を抑制できることがわかった。 As shown in Table 23, the nonaqueous electrolyte secondary battery of Example 1-1 had a ratio of output at 0 ° C. to output at 25 ° C. at 2 seconds output and 5 seconds output (0 ° C. output / 25 ° C. output). However, the non-aqueous electrolyte secondary battery of Example 1-1 is almost the same as the non-aqueous electrolyte secondary battery of Comparative Example 1-1. It was found that the decrease in output at low temperatures can be suppressed.
  (評価例20:熱安定性)
 実施例1-1、比較例1-1の非水電解質二次電池の充電状態の正極に対する電解液の熱安定性を以下の方法で評価した。
(Evaluation Example 20: Thermal stability)
The thermal stability of the electrolyte solution with respect to the charged positive electrode of the nonaqueous electrolyte secondary battery of Example 1-1 and Comparative Example 1-1 was evaluated by the following method.
 非水電解質二次電池に対し、充電終止電圧4.2V、定電流定電圧条件で満充電した。満充電後の非水電解質二次電池を解体し、正極を取り出した。当該正極から得られた正極活物質層3mgおよび電解液1.8μLをステンレス製のパンに入れ、該パンを密閉した。密閉パンを用いて、窒素雰囲気下、昇温速度20℃/min.の条件で示差走査熱量分析を行い、DSC曲線を観察した。示差走査熱量測定装置としてRigaku DSC8230を使用した。実施例1-1の非水電解質二次電池の充電状態の正極活物質層と電解液を共存させた場合のDSCチャートを図61に示す。また、比較例1-1の非水電解質二次電池の充電状態の正極活物質層と電解液を共存させた場合のDSCチャートを図62にそれぞれ示す。 The nonaqueous electrolyte secondary battery was fully charged under a charge end voltage of 4.2 V and a constant current and constant voltage condition. The fully charged nonaqueous electrolyte secondary battery was disassembled and the positive electrode was taken out. 3 mg of the positive electrode active material layer obtained from the positive electrode and 1.8 μL of the electrolytic solution were placed in a stainless steel pan, and the pan was sealed. Using a sealed pan, under a nitrogen atmosphere, the heating rate was 20 ° C / min. The differential scanning calorimetry was performed under the conditions described above, and the DSC curve was observed. A Rigaku DSC8230 was used as a differential scanning calorimeter. FIG. 61 shows a DSC chart in the case where the positive electrode active material layer in the charged state of the nonaqueous electrolyte secondary battery of Example 1-1 and the electrolyte coexist. FIG. 62 shows DSC charts in the case where the positive electrode active material layer in the charged state of the nonaqueous electrolyte secondary battery of Comparative Example 1-1 and the electrolyte coexist.
 図61および図62の結果から明らかなように、実施例1-1の非水電解質二次電池における充電状態の正極と電解液を共存させた場合のDSC曲線はほとんど吸発熱ピークが観察されなかったのに対し、比較例1-1の非水電解質二次電池の充電状態の正極と電解液を共存させた場合のDSC曲線においては300℃付近に発熱ピークが観察された。この発熱ピークは、正極活物質と電解液とが反応した結果、生じたものと推定される。 As is apparent from the results of FIGS. 61 and 62, almost no endothermic peak is observed in the DSC curve of the nonaqueous electrolyte secondary battery of Example 1-1 when the charged positive electrode and the electrolyte coexist. On the other hand, an exothermic peak was observed at around 300 ° C. in the DSC curve when the positive electrode in the charged state of the nonaqueous electrolyte secondary battery of Comparative Example 1-1 and the electrolyte coexisted. This exothermic peak is presumed to have occurred as a result of the reaction between the positive electrode active material and the electrolytic solution.
 これらの結果から、本発明の電解液を用いた非水電解質二次電池は、従来の電解液を用いた非水電解質二次電池と比較して、正極活物質と電解液との反応性が低く、熱安定性に優れていることがわかる。 From these results, the non-aqueous electrolyte secondary battery using the electrolytic solution of the present invention is more reactive with the positive electrode active material and the electrolytic solution than the non-aqueous electrolyte secondary battery using the conventional electrolytic solution. It can be seen that it is low and has excellent thermal stability.
 ところで、上述したように、イミド塩はアルミニウム集電体を腐食し易いと考えられている。従来は、アルミニウム集電体を用いる場合には、当該アルミニウム集電体に腐食抑制のための保護皮膜を形成する目的で、電解液の金属塩の一部にLiPF等のリチウム塩を用いる必要があると考えられていた。例えば特開2013-145732の実施例では、電解液にイミド塩の4倍程度のLiPFを配合していた。これに対して、以下に示すように、本発明の電解液はアルミニウムを腐食させ難い。このため、本発明の非水電解質二次電池ではアルミニウム集電体を好適に用い得る。 By the way, as described above, imide salts are considered to easily corrode aluminum current collectors. Conventionally, when an aluminum current collector is used, it is necessary to use a lithium salt such as LiPF 6 as a part of the metal salt of the electrolytic solution in order to form a protective film for inhibiting corrosion on the aluminum current collector. There was thought to be. For example, in the example of JP2013-145732, LiPF 6 that is about four times the imide salt was blended in the electrolyte. On the other hand, as shown below, the electrolytic solution of the present invention hardly corrodes aluminum. Therefore, an aluminum current collector can be suitably used in the nonaqueous electrolyte secondary battery of the present invention.
  (評価例21:Alの溶出確認I)
 (EB4)
 電解液E8を用いた非水電解質二次電池を以下のとおり製造した。
 径13.82mm、面積1.5cm、厚み20μmのアルミニウム箔(JIS A1000番系)を作用極とし、対極は金属Liとした。セパレータは厚さ400μmのWhatmanガラス繊維濾紙:品番1825-055を用いた。
 作用極、対極、セパレータおよびE8の電解液を電池ケース(宝泉株式会社製 CR2032型コインセルケース)に収容して非水電解質二次電池を得た。
(Evaluation example 21: Al elution confirmation I)
(EB4)
A nonaqueous electrolyte secondary battery using the electrolytic solution E8 was produced as follows.
An aluminum foil (JIS A1000 series) having a diameter of 13.82 mm, an area of 1.5 cm 2 and a thickness of 20 μm was used as a working electrode, and the counter electrode was metal Li. As the separator, Whatman glass fiber filter paper having a thickness of 400 μm: No. 1825-055 was used.
A working electrode, a counter electrode, a separator, and an electrolyte solution of E8 were accommodated in a battery case (CR2032-type coin cell case manufactured by Hosen Co., Ltd.) to obtain a nonaqueous electrolyte secondary battery.
 EB4に対して、1mV/sの速度で3.1V~4.6V(vs.Li基準)の範囲でリニアスイープボルタンメトリー測定(所謂LSV)を10回繰り返した際の、電流と電極電位の変化を観察した。EB4の充放電1回目、2回目、3回目の電流と電極電位との関係を示すグラフを図63に示す。 Changes in current and electrode potential when linear sweep voltammetry measurement (so-called LSV) is repeated 10 times in a range of 3.1 V to 4.6 V (vs. Li reference) at a speed of 1 mV / s with respect to EB4. Observed. FIG. 63 shows a graph showing the relationship between the first and second, third and third currents and the electrode potential of EB4.
 図63から、作用極をAlとしたEB4では、4.0Vでは電流が殆ど確認されず、
4.3Vで一旦僅かに電流が増大するが、その後4.6Vまで大幅な増大は見られなかった。また、充放電の繰返しによって電流量は減少し定常化に向った。
 以上の結果から、本発明の電解液を使用するとともに正極にアルミニウム集電体を用いた非水電解質二次電池は、高電位でもAlの溶出が起こり難いと考えられる。Alの溶出が起こり難いとされる理由は明確ではないが、本発明の電解液は、従来の電解液とは金属塩と有機溶媒の種類、存在環境および金属塩濃度が異なり、従来の電解液に比べて、本発明の電解液に対するAlの溶解性が低いのではないかと推測する。
From FIG. 63, in EB4 in which the working electrode is Al, almost no current is confirmed at 4.0 V,
The current once increased slightly at 4.3 V, but no significant increase was observed up to 4.6 V thereafter. In addition, the amount of current decreased due to repeated charging and discharging, and it became a steady state.
From the above results, it is considered that the nonaqueous electrolyte secondary battery using the electrolytic solution of the present invention and using the aluminum current collector for the positive electrode hardly causes elution of Al even at a high potential. Although it is not clear why the elution of Al is unlikely to occur, the electrolytic solution of the present invention differs from the conventional electrolytic solution in the types of metal salt and organic solvent, the existing environment and the metal salt concentration. In comparison with this, it is presumed that the solubility of Al in the electrolytic solution of the present invention is low.
  (評価例22:作用極Alでのサイクリックボルタンメトリー評価)
 (EB5)
 電解液E8にかえて電解液E11を用いた以外は、EB4と同様にして非水電解質二次電池EB5を得た。
(Evaluation Example 22: Cyclic voltammetry evaluation with working electrode Al)
(EB5)
A nonaqueous electrolyte secondary battery EB5 was obtained in the same manner as EB4 except that the electrolytic solution E11 was used instead of the electrolytic solution E8.
 (EB6)
 電解液E8にかえて電解液E16を用いた以外は、EB4と同様にして、非水電解質二次電池EB6を得た。
(EB6)
A nonaqueous electrolyte secondary battery EB6 was obtained in the same manner as EB4, except that the electrolytic solution E16 was used instead of the electrolytic solution E8.
 (EB7)
 電解液E8にかえて電解液E19を用いた以外は、EB4と同様にして、非水電解質二次電池EB7を得た。
(EB7)
A nonaqueous electrolyte secondary battery EB7 was obtained in the same manner as EB4 except that the electrolytic solution E19 was used instead of the electrolytic solution E8.
(EB8)
 電解液E8にかえて電解液E13を用いた以外は、EB4と同様にして、非水電解質二次電池EB8を得た。
(EB8)
A nonaqueous electrolyte secondary battery EB8 was obtained in the same manner as EB4 except that the electrolytic solution E13 was used instead of the electrolytic solution E8.
 (CB4)
 電解液E8にかえて電解液C5を用いた以外は、EB4と同様にして、非水電解質二次電池CB4を得た。
(CB4)
A nonaqueous electrolyte secondary battery CB4 was obtained in the same manner as EB4 except that the electrolytic solution C5 was used instead of the electrolytic solution E8.
 (CB5)
 電解液E8にかえて電解液C6を用いた以外は、EB4と同様にして、非水電解質二次電池CB5を得た。
(CB5)
A nonaqueous electrolyte secondary battery CB5 was obtained in the same manner as EB4 except that the electrolytic solution C6 was used instead of the electrolytic solution E8.
 非水電解質二次電池EB4~EB7およびCB4に対して、3.1V~4.6V、1mV/sの条件で5サイクルのサイクリックボルタンメトリー評価を行い、その後、3.1V~5.1V、1mV/sの条件で5サイクルのサイクリックボルタンメトリー評価を行った。 The non-aqueous electrolyte secondary batteries EB4 to EB7 and CB4 were subjected to cyclic voltammetry evaluation for 5 cycles under conditions of 3.1 V to 4.6 V and 1 mV / s, and then 3.1 V to 5.1 V and 1 mV. Cyclic voltammetry was evaluated for 5 cycles under the conditions of / s.
 また、ハーフセルEB5、EB8およびCB5に対して、3.0V~4.5V、1mV/sの条件で、10サイクルのサイクリックボルタンメトリー評価を行い、その後、3.0V~5.0V、1mV/sの条件で、10サイクルのサイクリックボルタンメトリー評価を行った。 In addition, 10 cycles of cyclic voltammetry evaluation was performed on the half cells EB5, EB8 and CB5 under the conditions of 3.0 V to 4.5 V and 1 mV / s, and then 3.0 V to 5.0 V and 1 mV / s. Under these conditions, 10 cycles of cyclic voltammetry evaluation was performed.
 EB4~EB7およびCB4に対する電位と応答電流との関係を示すグラフを図64~図72に示す。また、EB5、EB8およびCB5に対する電位と応答電流との関係を示すグラフを図73~図78に示す。 64 to 72 are graphs showing the relationship between the potential and response current for EB4 to EB7 and CB4. Further, graphs showing the relationship between the potential and response current for EB5, EB8, and CB5 are shown in FIGS.
 図72から、CB4では、2サイクル以降も3.1Vから4.6Vにかけて電流が流れ、高電位になるに従い電流が増大しているのがわかる。また、図77および図78から、CB5においても同様に、2サイクル以降も3.0Vから4.5Vにかけて電流が流れ、高電位になるに従い電流が増大している。この電流は、作用極のアルミニウムが腐食したことによるAlの酸化電流と推定される。 72, it can be seen that in CB4, the current flows from 3.1 V to 4.6 V after the second cycle, and the current increases as the potential increases. 77 and 78, in CB5 as well, the current flows from 3.0 V to 4.5 V in the second and subsequent cycles, and the current increases as the potential increases. This current is presumed to be the oxidation current of Al due to the corrosion of the working electrode aluminum.
 他方、図64~図71から、EB4~EB7では2サイクル以降は3.1Vから4.6Vにかけてほとんど電流が流れていないことがわかる。4.3V以上では電位上昇に伴いわずかに電流の増大が観察されるものの、サイクルを繰り返すに従い、電流の量は減少し、定常状態に向かった。特に、EB5~EB7は、高電位である5.1Vまで電流の顕著な増大が観察されず、しかも、サイクルの繰り返しに伴い電流量の減少が観察された。 On the other hand, it can be seen from FIGS. 64 to 71 that in EB4 to EB7, almost no current flows from 3.1 V to 4.6 V after the second cycle. Although a slight increase in current was observed as the potential increased at 4.3 V or higher, the amount of current decreased as the cycle was repeated, and the steady state was reached. In particular, in EB5 to EB7, no significant increase in current was observed up to a high potential of 5.1 V, and a decrease in the amount of current was observed with the repetition of the cycle.
 また、図73~図76から、EB5およびEB8においても同様に、2サイクル以降は3.0Vから4.5Vにかけてほとんど電流が流れていないことがわかる。特に3サイクル目以降では4.5Vに至るまで電流の増大はほぼない。そして、EB8では高電位となる4.5V以降に電流の増大がみられるが、これはCB5における4.5V以降の電流値に比べると遙かに小さい値である。EB5については、4.5V以降も5.0Vに至るまで電流の増大はほぼなく、EB5~EB7と同様に、サイクルの繰り返しに伴い電流量の減少が観察された。 73 to 76, similarly, in EB5 and EB8, it can be seen that almost no current flows from 3.0V to 4.5V after the second cycle. In particular, after the third cycle, there is almost no increase in current up to 4.5V. In EB8, an increase in current is observed after 4.5 V, which is a high potential, which is much smaller than the current value after 4.5 V in CB5. For EB5, there was almost no increase in current from 4.5V to 5.0V, and a decrease in the amount of current was observed as the cycle was repeated, as in EB5 to EB7.
 サイクリックボルタンメトリー評価の結果から、5Vを超える高電位条件でも、電解液E8、E11、E16、およびE19のアルミニウムに対する腐食性は低いといえる。すなわち、電解液E8、E11、E16、およびE19は、集電体などにアルミニウムを用いた電池に対し、好適な電解液といえる。 From the results of cyclic voltammetry evaluation, it can be said that the corrosiveness of the electrolytes E8, E11, E16, and E19 to aluminum is low even under high potential conditions exceeding 5V. That is, the electrolytes E8, E11, E16, and E19 can be said to be suitable electrolytes for batteries using aluminum as a current collector or the like.
  (評価例23:Alの溶出確認II)
 実施例1-1、実施例1-2および比較例1-1の非水電解質二次電池を、使用電圧範囲3V~4.2Vとし、レート1Cで充放電を100回繰り返し、充放電100回後に解体し、負極を取り出した。正極から電解液に溶出し、負極の表面へ沈着したAlの量をICP(高周波誘導結合プラズマ)発光分光分析装置で測定した。測定結果を表24に示す。表24のAl量(%)は負極活物質層1gあたりのAlの質量を%で示したものであり、Al量(μg/枚)は、負極活物質層1枚あたりのAlの質量(μg)を表し、Al量(%)÷100×各負極活物質層1枚の質量=Al量(μg/枚)の計算式により算出した。
(Evaluation Example 23: Confirmation of Al Elution II)
The nonaqueous electrolyte secondary batteries of Example 1-1, Example 1-2, and Comparative Example 1-1 were set to a working voltage range of 3 V to 4.2 V, and charging / discharging was repeated 100 times at a rate of 1 C. After dismantling, the negative electrode was taken out. The amount of Al eluted from the positive electrode into the electrolyte and deposited on the surface of the negative electrode was measured with an ICP (high frequency inductively coupled plasma) emission spectrometer. The measurement results are shown in Table 24. The amount of Al (%) in Table 24 indicates the mass of Al per gram of the negative electrode active material layer in%, and the amount of Al (μg / sheet) is the mass of Al per one layer of negative electrode active material layer (μg ) And calculated by the formula of Al amount (%) ÷ 100 × mass of each negative electrode active material layer = Al amount (μg / sheet).
Figure JPOXMLDOC01-appb-T000024
Figure JPOXMLDOC01-appb-T000024
 実施例1-1および実施例1-2の非水電解質二次電池では、比較例1-1の非水電解質二次電池よりも、負極表面に沈着しているAlの量が大幅に少なかった。このことから、本発明の電解液を用いた実施例1-1および実施例1-2の非水電解質二次電池では、従来の電解液を用いた比較例1-1の非水電解質二次電池よりも正極の集電体からのAlの溶出が抑制されたことがわかった。 In the nonaqueous electrolyte secondary batteries of Example 1-1 and Example 1-2, the amount of Al deposited on the negative electrode surface was significantly smaller than that of the nonaqueous electrolyte secondary battery of Comparative Example 1-1. . Therefore, in the nonaqueous electrolyte secondary batteries of Example 1-1 and Example 1-2 using the electrolytic solution of the present invention, the nonaqueous electrolyte secondary battery of Comparative Example 1-1 using the conventional electrolytic solution is used. It was found that the elution of Al from the positive electrode current collector was suppressed more than the battery.
  (評価例24:Al集電体の表面分析)
 実施例1-1および実施例1-2の非水電解質二次電池を、使用電圧範囲3V~4.2Vとし、レート1Cで充放電を100回繰り返し、充放電100回後に解体し、正極用集電体であるアルミニウム箔を各々取り出し、アルミニウム箔の表面をジメチルカーボネートで洗浄した。
(Evaluation Example 24: Surface analysis of Al current collector)
The nonaqueous electrolyte secondary batteries of Example 1-1 and Example 1-2 were set to a working voltage range of 3 V to 4.2 V, charged and discharged at a rate of 1 C 100 times, disassembled after 100 times of charging and discharging, and used for the positive electrode Each aluminum foil as a current collector was taken out, and the surface of the aluminum foil was washed with dimethyl carbonate.
 洗浄後の実施例1-1および実施例1-2の非水電解質二次電池のアルミニウム箔の表面を、ArスパッタでエッチングしながらX線光電子分光法(XPS)にて表面分析を行った。実施例1-1および実施例1-2の非水電解質二次電池の充放電後のアルミニウム箔の表面分析結果を図79および図80に示す。 The surface of the aluminum foil of the non-aqueous electrolyte secondary battery of Example 1-1 and Example 1-2 after cleaning was subjected to surface analysis by X-ray photoelectron spectroscopy (XPS) while being etched by Ar sputtering. 79 and 80 show the surface analysis results of the aluminum foil after charge / discharge of the nonaqueous electrolyte secondary batteries of Example 1-1 and Example 1-2.
 図79および図80を比べると、実施例1-1および実施例1-2の非水電解質二次電池の充放電後の正極用集電体であるアルミニウム箔の表面分析結果は両者ともほぼ同じであり、以下のことがいえる。アルミニウム箔の表面において、最表面のAlの化学状態はAlFであった。アルミニウム箔を深さ方向にエッチングしていくと、Al、O、Fのピークが検出された。アルミニウム箔を表面から1回~3回エッチングしていった箇所では、Alの化学状態はAl-F結合およびAl-O結合の複合状態であることがわかった。さらにエッチングしていくと4回エッチング(SiO換算で深さ約25nm)したところからO、Fのピークが消失し、Alのみのピークが観察された。なお、XPS測定データにおいて、AlFは、Alピーク位置76.3eVに観察され、純Alは、Alピーク位置73eVに観察され、Al-F結合およびAl-O結合の複合状態では、Alピーク位置74eV~76.3eVに観察される。図79および図80に示す破線は、AlF、Al、Alそれぞれの代表的なピーク位置を示す。 79 and 80 are compared, the surface analysis results of the aluminum foil as the positive electrode current collector of the nonaqueous electrolyte secondary batteries of Examples 1-1 and 1-2 are almost the same. The following can be said. On the surface of the aluminum foil, the chemical state of Al on the outermost surface was AlF 3 . When the aluminum foil was etched in the depth direction, peaks of Al, O, and F were detected. It was found that the chemical state of Al was a composite state of Al—F bond and Al—O bond at the place where the aluminum foil was etched once to three times from the surface. As the etching was further continued, the O and F peaks disappeared from the fourth etching (depth about 25 nm in terms of SiO 2 ), and only the Al peak was observed. In the XPS measurement data, AlF 3 is observed at the Al peak position 76.3 eV, pure Al is observed at the Al peak position 73 eV, and in the combined state of Al—F bond and Al—O bond, the Al peak position is observed. Observed at 74 eV-76.3 eV. The broken lines shown in FIGS. 79 and 80 show typical peak positions of AlF 3 , Al, and Al 2 O 3, respectively.
 以上の結果から、本発明の充放電後の非水電解質二次電池のアルミニウム箔の表面には、深さ方向に約25nmの厚みで、Al-F結合(AlFと推測される)の層と、Al-F結合(AlFと推測される)およびAl-O結合(Alと推測される)の混在する層とが形成されていることが確認できた。 From the above results, an Al—F bond (presumed to be AlF 3 ) layer having a thickness of about 25 nm in the depth direction is formed on the surface of the aluminum foil of the non-aqueous electrolyte secondary battery after charge / discharge of the present invention. It was confirmed that a layer in which Al—F bonds (presumed to be AlF 3 ) and Al—O bonds (presumed to be Al 2 O 3 ) were mixed was formed.
 つまり、正極集電体にアルミニウム箔を用いた本発明の非水電解質二次電池において、本発明の電解液を用いても充放電後にはアルミニウム箔の最表面にはAl-F結合(AlFと推測される)からなる不動態膜が形成されることがわかった。 That is, in the non-aqueous electrolyte secondary battery of the present invention using an aluminum foil as a positive electrode current collector, an Al—F bond (AlF 3) is formed on the outermost surface of the aluminum foil after charge / discharge even when the electrolyte of the present invention is used. It was found that a passive film consisting of
 評価例21~評価例24の結果から、本発明の電解液と、アルミニウムまたはアルミニウム合金からなる正極用集電体とを組み合わせる非水電解質二次電池では、充放電により正極用集電体の表面には不動態膜が形成され、なおかつ、高電位状態においても正極用集電体からのAlの溶出が抑制されることがわかった。 From the results of Evaluation Examples 21 to 24, in the nonaqueous electrolyte secondary battery in which the electrolytic solution of the present invention and the positive electrode current collector made of aluminum or an aluminum alloy are combined, the surface of the positive electrode current collector is charged and discharged. It was found that a passive film was formed on the electrode and that elution of Al from the positive electrode current collector was suppressed even in a high potential state.
 (評価例25:正極S,O含有皮膜分析)
 TOF-SIMS(Time-of-Flight Secondary Ion Mass Spectrometry:飛行時間型二次イオン質量分析法)を用いて、実施例1-4の正極S,O含有皮膜に含まれる各分子の構造情報を分析した。
(Evaluation Example 25: Analysis of coating film containing positive electrode S and O)
Using TOF-SIMS (Time-of-Flight Secondary Ion Mass Spectrometry), structural information of each molecule contained in the positive electrode S, O-containing film of Example 1-4 is analyzed. did.
 実施例1-4の非水電解質二次電池を25℃で3サイクル充放電した後、3V放電状態で解体し正極を取り出した。これとは別に、実施例1-4の非水電解質二次電池を25℃で500サイクル充放電した後、3V放電状態で解体し正極を取り出した。さらにこれとは別に、実施例1-4の非水電解質二次電池を25℃で3サイクル充放電した後、60℃で一か月間放置し、3V放電状態で解体し正極を取り出した。各正極をDMCで3回洗浄し、分析用の正極を得た。なお、当該正極には正極S,O含有皮膜が形成され、以下の分析では正極S,O含有皮膜に含まれる分子の構造情報が分析された。 The nonaqueous electrolyte secondary battery of Example 1-4 was charged and discharged at 25 ° C. for 3 cycles, then disassembled in a 3V discharge state, and the positive electrode was taken out. Separately, the nonaqueous electrolyte secondary battery of Example 1-4 was charged and discharged for 500 cycles at 25 ° C., then disassembled in a 3V discharge state, and the positive electrode was taken out. Separately from this, the nonaqueous electrolyte secondary battery of Example 1-4 was charged and discharged at 25 ° C. for 3 cycles, then left at 60 ° C. for 1 month, disassembled in a 3 V discharge state, and the positive electrode was taken out. Each positive electrode was washed with DMC three times to obtain a positive electrode for analysis. In addition, the positive electrode S and O containing film was formed in the said positive electrode, and the structural information of the molecule | numerator contained in the positive electrode S and O containing film was analyzed in the following analysis.
 分析用の各正極を、TOF-SIMSにより分析した。質量分析計としては飛行時間型二次イオン質量分析計を用い、正二次イオンおよび負二次イオンを測定した。一次イオン源としてはBiを用い、一次加速電圧は25kVであった。スパッタイオン源としてはAr-GCIB(Ar1500)を用いた。測定結果を表25~表27に示す。なお、表26における各フラグメントの正イオン強度(相対値)とは、検出された全てのフラグメントの正イオン強度の総和を100%とした相対値である。同様に、表27に記載した各フラグメントの負イオン強度(相対値)とは、検出された全てのフラグメントの負イオン強度の総和を100%とした相対値である。 Each positive electrode for analysis was analyzed by TOF-SIMS. A time-of-flight secondary ion mass spectrometer was used as a mass spectrometer, and positive secondary ions and negative secondary ions were measured. Bi was used as the primary ion source, and the primary acceleration voltage was 25 kV. Ar-GCIB (Ar1500) was used as the sputter ion source. The measurement results are shown in Table 25 to Table 27. In Table 26, the positive ion intensity (relative value) of each fragment is a relative value with the total positive ion intensity of all detected fragments as 100%. Similarly, the negative ionic strength (relative value) of each fragment described in Table 27 is a relative value where the sum of the negative ionic strengths of all the detected fragments is 100%.
Figure JPOXMLDOC01-appb-T000025
Figure JPOXMLDOC01-appb-T000025
Figure JPOXMLDOC01-appb-T000026
Figure JPOXMLDOC01-appb-T000026
Figure JPOXMLDOC01-appb-T000027
Figure JPOXMLDOC01-appb-T000027
 表25に示すように電解液の溶媒由来と推定されるフラグメントは、正二次イオンとして検出されたCおよびCのみであった。また、電解液の塩由来と推定されるフラグメントは、主に負二次イオンとして検出され、上記した溶媒由来のフラグメントに比べてイオン強度が大きい。さらに、Liを含むフラグメントは主に正二次イオンとして検出され、Liを含むフラグメントのイオン強度は、正二次イオンおよび負二次イオンのなかでも大きな割合を占める。 As shown in Table 25, the only fragments presumed to be derived from the solvent of the electrolytic solution were C 3 H 3 and C 4 H 3 detected as positive secondary ions. In addition, a fragment presumed to be derived from a salt of the electrolytic solution is mainly detected as a negative secondary ion, and has a higher ionic strength than the above-described fragment derived from a solvent. Furthermore, fragments containing Li are mainly detected as positive secondary ions, and the ionic strength of the fragments containing Li accounts for a large proportion of positive secondary ions and negative secondary ions.
 以上のことから、本発明のS,O含有皮膜の主成分は電解液に含まれる金属塩由来の成分であり、かつ、本発明のS,O含有皮膜には多くのLiが含まれると推測される。 From the above, it is speculated that the main component of the S, O-containing coating of the present invention is a component derived from the metal salt contained in the electrolytic solution, and that the S, O-containing coating of the present invention contains a large amount of Li. Is done.
 さらに、表25に示すように、塩由来と推定されるフラグメントとしてはSNO,SFO,SNO等も検出されている。これらは何れもS=O構造を有し、かつSに対してNやFが結合した構造である。つまり、本発明のS,O含有皮膜において、SはOと二重結合しているだけでなく、SNO,SFO,SNO等のように、他の元素と結合した構造をもとり得る。したがって、本発明のS,O含有皮膜は少なくともS=O構造を有していれば良く、S=O構造に含まれるSが他の元素と結合していても良いといえる。なお、当然乍ら、本発明のS,O含有皮膜はS=O構造をとらないSおよびOを含んでいても良い。 Furthermore, as shown in Table 25, SNO 2 , SFO 2 , S 2 F 2 NO 4, etc. are also detected as fragments presumed to be derived from salts. Each of these has an S═O structure, and N or F is bonded to S. That is, in the S, O-containing film of the present invention, S is not only double-bonded with O, but also has a structure bonded to other elements such as SNO 2 , SFO 2 , S 2 F 2 NO 4, etc. Can also be taken. Therefore, it can be said that the S, O-containing coating of the present invention has at least an S═O structure, and S contained in the S═O structure may be bonded to other elements. Naturally, the S, O-containing coating of the present invention may contain S and O which do not take the S = O structure.
 ところで、例えば上述した特開2013-145732に紹介されている従来型の電解液、つまり、有機溶媒としてのECと金属塩としてのLiPFと添加剤としてLiFSAとを含有する従来の電解液では、Sは有機溶媒の分解物に取り込まれる。このためSは、負極皮膜および/または正極皮膜中においてCS(p、qはそれぞれ独立した整数)等のイオンとして存在すると考えられる。これに対して、表25~表27に示すように、本発明のS,O含有皮膜から検出されたSを含有するフラグメントは、CSフラグメントではなくアニオン構造を反映したフラグメントが主体である。このことからも、本発明のS,O含有皮膜が従来の非水電解質二次電池に形成される皮膜とは根本的に異なることが明らかになる。 By the way, in the conventional electrolyte solution introduced in, for example, the above-mentioned JP2013-145732, that is, a conventional electrolyte solution containing EC as an organic solvent, LiPF 6 as a metal salt, and LiFSA as an additive, S is taken into the decomposition product of the organic solvent. For this reason, S is considered to exist as ions such as C p H q S (p and q are independent integers) in the negative electrode film and / or the positive electrode film. In contrast, as shown in Tables 25 to 27, the fragment containing S detected from the S, O-containing film of the present invention is not a C p H q S fragment but mainly a fragment reflecting an anion structure. It is. This also reveals that the S, O-containing coating of the present invention is fundamentally different from a coating formed on a conventional nonaqueous electrolyte secondary battery.
(その他の態様I)
 本発明の電解液を用いた非水電解質二次電池について、以下のとおり、電池特性を評価した。
(Other aspects I)
About the nonaqueous electrolyte secondary battery using the electrolyte solution of this invention, the battery characteristic was evaluated as follows.
 (EB9)
 電解液E8を用いた非水電解質二次電池を以下のとおり製造した。
 活物質である平均粒径10μmの黒鉛90質量部、および結着剤であるポリフッ化ビニリデン10質量部を混合した。この混合物を適量のN-メチル-2-ピロリドンに分散させて、スラリーを作製した。集電体として厚み20μmの銅箔を準備した。この銅箔の表面に、ドクターブレードを用いて、上記スラリーを膜状に塗布した。スラリーが塗布された銅箔を乾燥してN-メチル-2-ピロリドンを除去し、その後、銅箔をプレスし、接合物を得た。得られた接合物を真空乾燥機で120℃、6時間加熱乾燥して、活物質層が形成された銅箔を得た。これを作用極とした。なお、銅箔1cmあたりの活物質の質量は1.48mgであった。また、プレス前の黒鉛およびポリフッ化ビニリデンの密度は0.68g/cmであり、プレス後の活物質層の密度は1.025g/cmであった。
 対極は金属Liとした。
 作用極、対極、両者の間に挟装したセパレータとしての厚さ400μmのWhatmanガラス繊維ろ紙および電解液E8を、径13.82mmの電池ケース(宝泉株式会社製 CR2032型コインセルケース)に収容して非水電解質二次電池EB9を得た。
(EB9)
A nonaqueous electrolyte secondary battery using the electrolytic solution E8 was produced as follows.
90 parts by mass of graphite having an average particle diameter of 10 μm as an active material and 10 parts by mass of polyvinylidene fluoride as a binder were mixed. This mixture was dispersed in an appropriate amount of N-methyl-2-pyrrolidone to prepare a slurry. A copper foil having a thickness of 20 μm was prepared as a current collector. The slurry was applied in a film form on the surface of the copper foil using a doctor blade. The copper foil coated with the slurry was dried to remove N-methyl-2-pyrrolidone, and then the copper foil was pressed to obtain a bonded product. The obtained joined product was heat-dried at 120 ° C. for 6 hours with a vacuum dryer to obtain a copper foil on which an active material layer was formed. This was the working electrode. In addition, the mass of the active material per 1 cm 2 of copper foil was 1.48 mg. Further, the density of graphite and polyvinylidene fluoride before pressing was 0.68 g / cm 3 , and the density of the active material layer after pressing was 1.025 g / cm 3 .
The counter electrode was metal Li.
Whatman glass fiber filter paper having a thickness of 400 μm and electrolyte E8 as a separator sandwiched between the working electrode and the counter electrode are accommodated in a battery case (CR2032 type coin cell case manufactured by Hosen Co., Ltd.) with a diameter of 13.82 mm. Thus, a nonaqueous electrolyte secondary battery EB9 was obtained.
 (EB10)
 電解液E11を用いた以外は、EB9と同様の方法で、非水電解質二次電池EB10を得た。
(EB10)
A nonaqueous electrolyte secondary battery EB10 was obtained in the same manner as EB9 except that the electrolytic solution E11 was used.
 (EB11)
 電解液E16を用いた以外は、EB9と同様の方法で、非水電解質二次電池EB11を得た。
(EB11)
A nonaqueous electrolyte secondary battery EB11 was obtained in the same manner as EB9 except that the electrolytic solution E16 was used.
 (EB12)
 電解液E19を用いた以外は、EB9と同様の方法で、非水電解質二次電池EB12を得た。
(EB12)
A nonaqueous electrolyte secondary battery EB12 was obtained in the same manner as EB9 except that the electrolytic solution E19 was used.
 (CB6)
 電解液C5を用いた以外は、EB9と同様の方法で、非水電解質二次電池CB6を得た。
(CB6)
A nonaqueous electrolyte secondary battery CB6 was obtained in the same manner as EB9 except that the electrolytic solution C5 was used.
  (評価例26:レート特性)
 EB9~EB12、CB6のレート特性を以下の方法で試験した。各非水電解質二次電池に対し、0.1C、0.2C、0.5C、1C、2Cレートで充電を行った後に放電を行い、それぞれの速度における作用極の容量(放電容量)を測定した。なお、1Cとは一定電流において1時間で電池を完全充電または放電させるために要する電流値を意味する。また、ここでの記述は、対極を負極、作用極を正極とみなしている。0.1Cレートでの作用極の容量に対する他のレートにおける容量の割合(レート特性)を算出した。結果を表28に示す。
(Evaluation Example 26: Rate characteristics)
The rate characteristics of EB9 to EB12 and CB6 were tested by the following method. Each non-aqueous electrolyte secondary battery was charged at a rate of 0.1C, 0.2C, 0.5C, 1C, 2C, then discharged, and the capacity (discharge capacity) of the working electrode at each speed was measured. did. 1C means a current value required to fully charge or discharge the battery in one hour at a constant current. Further, in this description, the counter electrode is regarded as a negative electrode and the working electrode is regarded as a positive electrode. The ratio (rate characteristic) of the capacity at other rates to the capacity of the working electrode at the 0.1 C rate was calculated. The results are shown in Table 28.
Figure JPOXMLDOC01-appb-T000028
Figure JPOXMLDOC01-appb-T000028
 EB9、EB10、EB11、EB12は0.2C、0.5C、1Cのレートにおいて、さらに、EB9、EB10は2CのレートにおいてもCB6と比較して、容量低下が抑制されており、優れたレート特性を示すことが裏付けられた。 EB9, EB10, EB11, and EB12 are at rates of 0.2C, 0.5C, and 1C, and EB9 and EB10 are also at a rate of 2C, compared to CB6. It was confirmed that
  (評価例27:容量維持率)
 EB9~EB12、CB6の容量維持率を以下の方法で試験した。
 各非水電解質二次電池に対し、25℃、電圧2.0VまでCC充電(定電流充電)し、電圧0.01VまでCC放電(定電流放電)を行う2.0V-0.01Vの充放電サイクルを、充放電レート0.1Cで3サイクル行い、その後、0.2C、0.5C、1C、2C、5C、10Cの順で各充放電レートにつき3サイクルずつ充放電を行い、最後に0.1Cで3サイクル充放電を行った。各非水電解質二次電池の容量維持率(%)は以下の式で求めた。
 容量維持率(%)=B/A×100
 A:最初の0.1C充放電サイクルにおける2回目の作用極の放電容量
 B:最後の0.1Cの充放電サイクルにおける2回目の作用極の放電容量
 結果を表29に示す。なお、ここでの記述は、対極を負極、作用極を正極とみなしている。
(Evaluation Example 27: Capacity maintenance rate)
The capacity maintenance rates of EB9 to EB12 and CB6 were tested by the following method.
Each nonaqueous electrolyte secondary battery is CC charged (constant current charge) to 25 ° C. and a voltage of 2.0 V, and is subjected to CC discharge (constant current discharge) to a voltage of 0.01 V. The discharge cycle is performed for 3 cycles at a charge / discharge rate of 0.1 C, and thereafter, 3 cycles are charged and discharged for each charge / discharge rate in the order of 0.2 C, 0.5 C, 1 C, 2 C, 5 C, and 10 C. Three cycles of charge and discharge were performed at 0.1 C. The capacity retention rate (%) of each non-aqueous electrolyte secondary battery was determined by the following formula.
Capacity maintenance rate (%) = B / A × 100
A: Discharge capacity of the second working electrode in the first 0.1 C charge / discharge cycle B: Discharge capacity of the second working electrode in the last 0.1 C charge / discharge cycle Table 29 shows the results. In this description, the counter electrode is regarded as a negative electrode and the working electrode is regarded as a positive electrode.
Figure JPOXMLDOC01-appb-T000029
Figure JPOXMLDOC01-appb-T000029
 何れの非水電解質二次電池も、良好に充放電反応を行い、好適な容量維持率を示した。特に、EB10、EB11、EB12の容量維持率は著しく優れていた。 Any of the nonaqueous electrolyte secondary batteries performed a good charge / discharge reaction and showed a suitable capacity retention rate. In particular, the capacity retention rates of EB10, EB11, and EB12 were remarkably excellent.
  (評価例28:充放電の可逆性)
 EB9~EB12、CB6に対し、25℃、電圧2.0VまでCC充電(定電流充電)し、電圧0.01VまでCC放電(定電流放電)を行う2.0V-0.01Vの充放電サイクルを、充放電レート0.1Cで3サイクル行った。各非水電解質二次電池の充放電曲線を図81~図85に示す。
(Evaluation Example 28: Reversibility of charge / discharge)
EB9 to EB12 and CB6 are charged to 2.0V-0.01V by CC charge (constant current charge) to 25 ° C and voltage 2.0V, and CC discharge (constant current discharge) to voltage 0.01V For 3 cycles at a charge / discharge rate of 0.1 C. 81 to 85 show charge / discharge curves of each nonaqueous electrolyte secondary battery.
 図81~図85に示されるように、EB9~EB12は、一般的な電解液を用いたCB6と同様に、可逆的に充放電反応することがわかる。 81 to 85, it can be seen that EB9 to EB12 reversibly charge and discharge similarly to CB6 using a general electrolytic solution.
 (EB13)
 電解液E9を用いたこと以外はEB9と同様にして非水電解質二次電池EB13を得た。
(EB13)
A nonaqueous electrolyte secondary battery EB13 was obtained in the same manner as EB9 except that the electrolytic solution E9 was used.
  (評価例29:低温でのレート特性)
 EB13およびCB6を用い、-20℃でのレート特性を以下のとおり評価した。結果を図86および図87に示す。
 (1) 負極(評価極)へのリチウム吸蔵が進行する向きに電流を流す。
 (2) 電圧範囲:2V→0.01V(v.s.Li/Li+)
 (3) レート:0.02C、0.05C、0.1C、0.2C、0.5C (0.01V到達後に電流を停止)
 なお、1Cは、一定電流において1時間で電池を完全充電、または放電させるために要する電流値を示す。
(Evaluation Example 29: Rate characteristics at low temperature)
Using EB13 and CB6, the rate characteristics at −20 ° C. were evaluated as follows. The results are shown in FIGS. 86 and 87.
(1) A current is passed in the direction in which lithium occlusion proceeds to the negative electrode (evaluation electrode).
(2) Voltage range: 2V → 0.01V (vs Li / Li +)
(3) Rate: 0.02C, 0.05C, 0.1C, 0.2C, 0.5C (current stopped after reaching 0.01V)
1C represents a current value required to fully charge or discharge the battery in one hour at a constant current.
 図86および図87から、各電流レートにおけるEB13の電圧カーブは、CB6の電圧カーブと比較して、高い電圧を示しているのがわかる。この結果から、本発明の非水電解質二次電池は、低温環境においても優れたレート特性を示すことが裏付けられた。 86 and 87, it can be seen that the voltage curve of EB13 at each current rate shows a higher voltage than the voltage curve of CB6. From this result, it was confirmed that the nonaqueous electrolyte secondary battery of the present invention exhibits excellent rate characteristics even in a low temperature environment.
 (実施例2-1)
 ポリアクリル酸(PAA)を純水に溶解し、結着剤溶液を調製した。この結着剤溶液に、鱗片状黒鉛粉末を添加混合し、スラリー状の負極合材を調製した。スラリー中の各成分(固形分)の組成比は、黒鉛:PAA=90:10(質量比)である。
Example 2-1
Polyacrylic acid (PAA) was dissolved in pure water to prepare a binder solution. To this binder solution, flaky graphite powder was added and mixed to prepare a slurry-like negative electrode mixture. The composition ratio of each component (solid content) in the slurry is graphite: PAA = 90: 10 (mass ratio).
 このスラリーを、厚さ18μmの電解銅箔(集電体)の表面にドクターブレードを用いて塗布し、銅箔上に負極活物質層を形成した。 This slurry was applied onto the surface of an electrolytic copper foil (current collector) having a thickness of 18 μm using a doctor blade, and a negative electrode active material layer was formed on the copper foil.
 その後、80℃で20分間乾燥し、負極活物質層から純水を蒸発させて除去した。乾燥後、ロールプレス機により、集電体と負極活物質層を強固に密着接合させた。これを80℃で6時間真空乾燥して、負極活物質層の厚さが30μm程度の負極を得た。 Then, it was dried at 80 ° C. for 20 minutes, and pure water was removed by evaporation from the negative electrode active material layer. After drying, the current collector and the negative electrode active material layer were firmly and closely joined with a roll press. This was vacuum-dried at 80 ° C. for 6 hours to obtain a negative electrode having a negative electrode active material layer thickness of about 30 μm.
 上記で作製した負極を評価極として用い、非水電解質二次電池(ハーフセル)を作製した。対極は、金属リチウム箔(厚さ500μm)とした。 Using the negative electrode prepared above as an evaluation electrode, a non-aqueous electrolyte secondary battery (half cell) was prepared. The counter electrode was a metal lithium foil (thickness 500 μm).
 対極をφ15mm、評価極をφ11mmに裁断し、セパレータ(厚さ400μmのWhatmanガラス繊維ろ紙)を両者の間に挟装して電極体電池とした。この電極体電池を電池ケース(宝泉株式会社製CR2032コインセル)に収容した。そして電解液E8を注入し、電池ケースを密閉して実施例2-1の非水電解質二次電池を得た。実施例2-1の非水電解質二次電池および以下の各実施例の非水電解質二次電池の詳細を、実施例の欄の文末の表40に示す。 The counter electrode was cut to φ15 mm, the evaluation electrode was cut to φ11 mm, and a separator (Whatman glass fiber filter paper having a thickness of 400 μm) was sandwiched between them to form an electrode body battery. This electrode body battery was accommodated in a battery case (CR2032 coin cell manufactured by Hosen Co., Ltd.). Then, the electrolyte solution E8 was injected, the battery case was sealed, and the nonaqueous electrolyte secondary battery of Example 2-1 was obtained. Details of the non-aqueous electrolyte secondary battery of Example 2-1 and the non-aqueous electrolyte secondary battery of each of the following examples are shown in Table 40 at the end of the column of Examples.
 (実施例2-2)
 結着剤としてPAAに代えてCMCとSBRとの混合物(質量比でCMC:SBR=1:1)を用い、質量比で活物質:結着剤=98:2となるように用いたこと以外は実施例2-1と同様にして負極を作製し、その他は実施例2-1と同様にして実施例2-2の非水電解質二次電池を得た。
(Example 2-2)
Other than using a mixture of CMC and SBR (mass ratio CMC: SBR = 1: 1) instead of PAA as the binder, and using the mass ratio of active material: binder = 98: 2. A negative electrode was produced in the same manner as in Example 2-1, and the other non-aqueous electrolyte secondary battery in Example 2-2 was obtained in the same manner as in Example 2-1.
 (比較例2-1)
 結着剤としてPAAに代えてPVdFをPAAと同量用いたこと以外は実施例2-1と同様にして負極を作製し、その他は実施例2-1と同様にして比較例2-1の非水電解質二次電池を得た。
(Comparative Example 2-1)
A negative electrode was prepared in the same manner as in Example 2-1, except that PVdF was used in the same amount as PAA in place of PAA as the binder, and the rest of Comparative Example 2-1 was performed in the same manner as in Example 2-1. A nonaqueous electrolyte secondary battery was obtained.
 (比較例2-2)
 結着剤としてPAAに代えてPVdFをPAAと同量用いたこと以外は実施例2-1と同様にして負極を作製した。この負極を評価極として用い、電解液E8に代えて電解液C5を用いたこと以外は実施例2-1と同様にして非水電解質二次電池を得た。
(Comparative Example 2-2)
A negative electrode was produced in the same manner as in Example 2-1, except that PVdF was used in the same amount as PAA instead of PAA as a binder. Using this negative electrode as an evaluation electrode, a nonaqueous electrolyte secondary battery was obtained in the same manner as in Example 2-1, except that the electrolytic solution C5 was used instead of the electrolytic solution E8.
 実施例2-1および2-2と比較例2-1および2-2の非水電解質二次電池を用い、レート容量特性、サイクル容量維持率、負荷特性をそれぞれ評価した。 Using the nonaqueous electrolyte secondary batteries of Examples 2-1 and 2-2 and Comparative Examples 2-1 and 2-2, the rate capacity characteristics, the cycle capacity retention ratio, and the load characteristics were evaluated.
  (評価例30:レート容量)
 (1) 負極へのリチウム吸蔵が進行する向きに電流を流す。
 (2) 電圧範囲:2V→0.01V(v.s.Li/Li
 (3) レート:0.1C、0.2C、0.5C、1C、2C、5C、10C、0.1C (0.01V到達後に電流を停止)
 (4) 各レート3回ずつ(合計24サイクル)測定
(Evaluation Example 30: Rate capacity)
(1) Current is passed in the direction in which lithium occlusion proceeds to the negative electrode.
(2) Voltage range: 2 V → 0.01 V (vs. Li / Li + )
(3) Rate: 0.1C, 0.2C, 0.5C, 1C, 2C, 5C, 10C, 0.1C (current is stopped after reaching 0.01V)
(4) 3 times for each rate (total 24 cycles)
 上記の条件にて0.1Cの電流容量と各Cレートにおける電流容量を測定し、0.1Cの電流容量に対する2Cレートの電流容量の比と、0.1Cの電流容量に対する5Cレートの電流容量の比を求めた。結果を表30に示す。なお、1Cは、一定電流において1時間で電池を完全充電、または放電させるために要する電流値を示す。 Under the above conditions, the current capacity of 0.1 C and the current capacity at each C rate are measured, the ratio of the current capacity of 2 C rate to the current capacity of 0.1 C, and the current capacity of 5 C rate to the current capacity of 0.1 C The ratio of was calculated. The results are shown in Table 30. 1C represents a current value required to fully charge or discharge the battery in one hour at a constant current.
  (評価例31:サイクル容量維持率)
 サイクル容量維持率として、1サイクル目の電流容量に対する25サイクル目の電流容量の比を算出した。結果を表30に示す。
(Evaluation Example 31: Cycle capacity maintenance rate)
As the cycle capacity retention rate, the ratio of the current capacity at the 25th cycle to the current capacity at the first cycle was calculated. The results are shown in Table 30.
Figure JPOXMLDOC01-appb-T000030
Figure JPOXMLDOC01-appb-T000030
 実施例2-1と比較例2-1との比較から、本発明の電解液にPAA結着剤を組み合わせることによって、本発明の電解液とPVdF結着剤との組み合わせに比べて、サイクル容量維持率と高レート側(5C/0.1C)における負荷特性が大きく向上していることがわかる。なお比較例2-2はサイクル容量維持率が高いことから、比較例2-1におけるサイクル容量維持率の低下現象は、本発明の電解液とPVdF結着剤の組み合わせにおける特有の現象と考えられる。 From the comparison between Example 2-1 and Comparative Example 2-1, the cycle capacity was compared with the combination of the electrolyte solution of the present invention and the PVdF binder by combining the electrolyte solution of the present invention with the PAA binder. It can be seen that the maintenance factor and the load characteristics on the high rate side (5C / 0.1C) are greatly improved. Since Comparative Example 2-2 has a high cycle capacity retention rate, the decrease in cycle capacity retention rate in Comparative Example 2-1 is considered to be a unique phenomenon in the combination of the electrolytic solution of the present invention and the PVdF binder. .
 また実施例2-2と比較例2-1との比較から、本発明の電解液とCMC-SBR結着剤との組み合わせによっても、本発明の電解液とPVdF結着剤との組み合わせに比べて、サイクル容量維持率と高レート側(5C/0.1C)における負荷特性が大きく向上していることがわかる。 Further, from the comparison between Example 2-2 and Comparative Example 2-1, the combination of the electrolytic solution of the present invention and the CMC-SBR binder was also compared with the combination of the electrolytic solution of the present invention and the PVdF binder. Thus, it can be seen that the cycle capacity retention rate and the load characteristics on the high rate side (5C / 0.1C) are greatly improved.
 なお比較例2-2ではPVdF結着剤を用いたにも関わらずサイクル容量維持率が高いので、本発明の電解液を用いる際には結着剤との適切な組み合わせが必要であることがわかる。 In Comparative Example 2-2, the cycle capacity retention rate is high in spite of the use of the PVdF binder, so that an appropriate combination with the binder may be necessary when using the electrolytic solution of the present invention. Recognize.
 実施例2-1、2-2と比較例2-1の非水電解質二次電池について初回充放電曲線を図88に示す。 FIG. 88 shows the initial charge / discharge curves for the nonaqueous electrolyte secondary batteries of Examples 2-1 and 2-2 and Comparative Example 2-1.
 図88から、比較例2-1では初回充電1.3V(対Li)付近に副反応が生じているのに対し、実施例2-1、2-2では本発明の電解液と結着剤の適切な組み合わせによって副反応が抑制されていることが確認される。このことによって、実施例2-1、2-2ではサイクル特性が向上したものと推察される。副反応が抑制される理由は定かではないが、親水基を有する結着剤による保護作用によるものかもしれない。 From FIG. 88, in Comparative Example 2-1, a side reaction occurred in the vicinity of the initial charge of 1.3 V (vs. Li), whereas in Examples 2-1 and 2-2, the electrolytic solution and the binder of the present invention It is confirmed that the side reaction is suppressed by an appropriate combination. From this, it is presumed that the cycle characteristics are improved in Examples 2-1 and 2-2. The reason why the side reaction is suppressed is not clear, but may be due to the protective action of the binder having a hydrophilic group.
 また、実施例2-1と比較例2-1の高レート側(5C)における充放電曲線を比較したところ、実施例2-1では電池反応に由来するプラトー領域が確認されたのに対し、比較例2-1では電池反応に由来するプラトー領域が確認できず、吸着系のメカニズムによる僅かな充電容量が得られただけであった。このことから、実施例2-1において負荷特性が向上したのは、吸着容量が増大したためではなく、PAA結着剤のリチウム供給作用によって濃度過電圧が低下した結果であると推察される。 Further, when the charge / discharge curves on the high rate side (5C) of Example 2-1 and Comparative Example 2-1 were compared, in Example 2-1, a plateau region derived from the battery reaction was confirmed. In Comparative Example 2-1, the plateau region derived from the battery reaction could not be confirmed, and only a small charge capacity was obtained due to the mechanism of the adsorption system. From this, it is presumed that the load characteristics in Example 2-1 were improved not because the adsorption capacity increased, but because the concentration overvoltage decreased due to the lithium supply action of the PAA binder.
 (実施例2-3)
 CMCとSBRとの混合物(質量比でCMC:SBR=1:1)を純水に溶解し、結着剤溶液を調製した。この結着剤溶液に、黒鉛粉末を添加混合し、スラリー状の負極合剤を調製した。スラリー中の各成分(固形分)の組成比は、黒鉛:CMC:SBR=98:1:1(質量比)である。
(Example 2-3)
A mixture of CMC and SBR (CMC: SBR = 1: 1 by mass) was dissolved in pure water to prepare a binder solution. To this binder solution, graphite powder was added and mixed to prepare a slurry-like negative electrode mixture. The composition ratio of each component (solid content) in the slurry is graphite: CMC: SBR = 98: 1: 1 (mass ratio).
 厚さ20μmの電解銅箔を負極用集電体とし、この負極用集電体の表面にドクターブレードを用いて上記のスラリーを塗布し、集電体上に負極活物質層を形成した。 An electrolytic copper foil having a thickness of 20 μm was used as a negative electrode current collector, and the slurry was applied to the surface of the negative electrode current collector using a doctor blade to form a negative electrode active material layer on the current collector.
 その後、80℃で20分間乾燥し、負極活物質層から有機溶媒を揮発させて除去した。乾燥後、ロールプレス機により、負極用集電体と負極活物質層を強固に密着接合させた。これを100℃で6時間真空乾燥して、負極活物質層の目付けが8.5mg/cm程度の負極を形成した。 Then, it dried at 80 degreeC for 20 minute (s), and the organic solvent was volatilized and removed from the negative electrode active material layer. After drying, the negative electrode current collector and the negative electrode active material layer were firmly bonded to each other by a roll press. This was vacuum-dried at 100 ° C. for 6 hours to form a negative electrode having a negative electrode active material layer weight of about 8.5 mg / cm 2 .
 正極活物質層は、正極活物質と、結着剤と、導電助剤とを有する。正極活物質としてはNCM523を用い、結着剤としてはPVDFを用い、導電助剤としてはABを用いた。正極用集電体は、厚み20μmのアルミニウム箔からなる。正極活物質層を100質量部としたときの、正極活物質と結着剤と導電助剤との含有質量比は、94:3:3である。 The positive electrode active material layer has a positive electrode active material, a binder, and a conductive additive. NCM523 was used as the positive electrode active material, PVDF was used as the binder, and AB was used as the conductive assistant. The positive electrode current collector is made of an aluminum foil having a thickness of 20 μm. When the positive electrode active material layer is 100 parts by mass, the mass ratio of the positive electrode active material, the binder, and the conductive additive is 94: 3: 3.
 NCM523、PVDFおよびABを上記の質量比となるように混合し、溶剤としてのNMPを添加してペースト状の正極合剤を得た。このペースト状の正極合剤を、正極用集電体の表面にドクターブレードを用いて塗布して、正極活物質層を形成した。正極活物質層を、80℃で20分間乾燥することで、NMPを揮発により除去した。正極活物質層と正極用集電体との複合物をロ-ルプレス機を用いて圧縮し、正極用集電体と正極活物質層とを強固に密着接合させた。得られた接合物を120℃で6時間、真空乾燥機で加熱し、所定の形状に切り取り、正極を得た。 NCM523, PVDF and AB were mixed so as to have the above mass ratio, and NMP as a solvent was added to obtain a paste-like positive electrode mixture. The paste-like positive electrode mixture was applied to the surface of the positive electrode current collector using a doctor blade to form a positive electrode active material layer. The positive electrode active material layer was dried at 80 ° C. for 20 minutes to remove NMP by volatilization. The composite of the positive electrode active material layer and the positive electrode current collector was compressed using a roll press, and the positive electrode current collector and the positive electrode active material layer were firmly bonded. The obtained joined product was heated with a vacuum dryer at 120 ° C. for 6 hours, cut into a predetermined shape, and a positive electrode was obtained.
 上記の正極、負極および電解液E8を用いて、非水電解質二次電池の一種であるラミネート型リチウムイオン二次電池を製作した。詳しくは、正極および負極の間に、セパレータとしてセルロース不織布(厚み20μm)を挟装して極板群とした。この極板群を二枚一組のラミネートフィルムで覆い、三辺をシールした後、袋状となったラミネートフィルムに上記電解液を注入した。その後、残りの一辺をシールすることで、四辺が気密にシールされ、極板群および電解液が密閉された実施例2-3の非水電解質二次電池を得た。 Using the above positive electrode, negative electrode, and electrolytic solution E8, a laminate type lithium ion secondary battery, which is a kind of non-aqueous electrolyte secondary battery, was manufactured. Specifically, a cellulose nonwoven fabric (thickness 20 μm) was sandwiched as a separator between the positive electrode and the negative electrode to form an electrode plate group. The electrode plate group was covered with a set of two laminated films, and the three sides were sealed, and then the electrolyte solution was poured into the bag-like laminated film. Thereafter, the remaining one side was sealed to obtain a nonaqueous electrolyte secondary battery of Example 2-3 in which the four sides were hermetically sealed and the electrode plate group and the electrolyte were sealed.
 (比較例2-3)
 結着剤としてCMC-SBRに代えてPVdFを10質量%用いたこと以外は実施例2-3と同様にして負極を作製し、その他は実施例2-3と同様にして比較例2-3の非水電解質二次電池を得た。
(Comparative Example 2-3)
A negative electrode was produced in the same manner as in Example 2-3 except that 10% by mass of PVdF was used instead of CMC-SBR as a binder, and Comparative Example 2-3 was made in the same manner as in Example 2-3. A non-aqueous electrolyte secondary battery was obtained.
 (比較例2-4)
 電解液E8に代えて電解液C5を用いたこと以外は実施例2-3と同様にして比較例2-4の非水電解質二次電池を得た。
(Comparative Example 2-4)
A nonaqueous electrolyte secondary battery of Comparative Example 2-4 was obtained in the same manner as in Example 2-3 except that the electrolytic solution C5 was used instead of the electrolytic solution E8.
 (比較例2-5)
 負極活物質である天然黒鉛90質量部、および結着剤であるPVdF10質量部を混合した。この混合物を適量のイオン交換水に分散させて、スラリー状の負極合剤を得た。負極用集電体として厚み20μmの銅箔を準備した。この負極用集電体の表面に、ドクターブレードを用いて、上記負極合剤を膜状に塗布した。負極合剤と負極用集電体との複合物を乾燥して水を除去し、その後プレスして、接合物を得た。得られた接合物を真空乾燥機で120℃、6時間加熱乾燥して、負極用集電体上に負極活物質層が形成された負極を得た。
(Comparative Example 2-5)
90 parts by mass of natural graphite as a negative electrode active material and 10 parts by mass of PVdF as a binder were mixed. This mixture was dispersed in an appropriate amount of ion-exchanged water to obtain a slurry-like negative electrode mixture. A copper foil having a thickness of 20 μm was prepared as a negative electrode current collector. The negative electrode mixture was applied to the surface of the negative electrode current collector in the form of a film using a doctor blade. The composite of the negative electrode mixture and the negative electrode current collector was dried to remove water, and then pressed to obtain a bonded product. The obtained joined product was heat-dried at 120 ° C. for 6 hours with a vacuum dryer to obtain a negative electrode having a negative electrode active material layer formed on a negative electrode current collector.
 正極は、実施例2-3の非水電解質二次電池の正極と同様に製造した。この正極、負極および電解液C5を用いた事以外は実施例2-3と同様にして、比較例2-5の非水電解質二次電池を得た。 The positive electrode was produced in the same manner as the positive electrode of the nonaqueous electrolyte secondary battery in Example 2-3. A nonaqueous electrolyte secondary battery of Comparative Example 2-5 was obtained in the same manner as Example 2-3 except that this positive electrode, negative electrode, and electrolytic solution C5 were used.
  (評価例32:入出力特性)
 実施例2-3と比較例2-3~2-5の非水電解質二次電池を用い、以下の条件で入力(充電)特性を評価した。
 (1) 使用電圧範囲:3V-4.2V
 (2) 容量:13.5mAh
 (3) SOC80%
 (4) 温度:0℃、25℃
 (5) 測定回数:各3回
(Evaluation Example 32: Input / output characteristics)
Using the nonaqueous electrolyte secondary batteries of Example 2-3 and Comparative Examples 2-3 to 2-5, the input (charging) characteristics were evaluated under the following conditions.
(1) Working voltage range: 3V-4.2V
(2) Capacity: 13.5mAh
(3) SOC 80%
(4) Temperature: 0 ° C, 25 ° C
(5) Number of measurements: 3 times each
 評価条件は、充電状態(SOC)80%、0℃、25℃、使用電圧範囲3V-4.2V、容量13.5mAhである。SOC80%、0℃は、例えば、冷蔵室などで使用する場合のように入力特性が出にくい領域である。実施例2-3と比較例2-3、2-4の入力特性の評価は、それぞれ2秒入力と5秒入力について3回行った。入力特性の評価結果を表31、表32に示した。表の中の「2秒入力」は、充電開始から2秒後での入力を意味し、「5秒入力」は充電開始から5秒後での入力を意味している。なお表31、32には、実施例2-3および比較例2-3に用いた電解液E8を「FSA」と略記し、比較例2-4および比較例2-5に用いた電解液C5を「ECPF」と略記している。 Evaluation conditions are 80% charged state (SOC), 0 ° C., 25 ° C., operating voltage range 3V-4.2V, and capacity 13.5 mAh. SOC 80%, 0 ° C. is a region in which input characteristics are difficult to be obtained, for example, when used in a refrigerator room. The input characteristics of Example 2-3 and Comparative Examples 2-3 and 2-4 were evaluated three times for 2-second input and 5-second input, respectively. Tables 31 and 32 show the evaluation results of the input characteristics. “2-second input” in the table means an input after 2 seconds from the start of charging, and “5-second input” means an input after 5 seconds from the start of charging. In Tables 31 and 32, the electrolytic solution E8 used in Example 2-3 and Comparative Example 2-3 is abbreviated as “FSA”, and the electrolytic solution C5 used in Comparative Example 2-4 and Comparative Example 2-5. Is abbreviated as “ECPF”.
Figure JPOXMLDOC01-appb-T000031
Figure JPOXMLDOC01-appb-T000031
Figure JPOXMLDOC01-appb-T000032
Figure JPOXMLDOC01-appb-T000032
 0℃および25℃の両方で、実施例2-3の方が比較例2-3~2-5に比べて入力(充電)特性が向上している。これは親水基を有する結着剤(CMC-SBR)と本発明の電解液を併用したことによる効果であり、特に0℃においても高い入力(充電)特性を示すことから、低温においても電解液中のリチウムイオンの移動が円滑に進行することが示されている。 At both 0 ° C. and 25 ° C., Example 2-3 has improved input (charging) characteristics compared to Comparative Examples 2-3 to 2-5. This is due to the combined use of the binder having a hydrophilic group (CMC-SBR) and the electrolytic solution of the present invention. In particular, it exhibits high input (charge) characteristics even at 0 ° C. It has been shown that the movement of the lithium ions in them proceeds smoothly.
 (実施例2-4)
 結着剤としてPAAに代えてCMCとSBRとの混合物(質量比でCMC:SBR=1:1)を用い、質量比で活物質:結着剤=98:2となるように用いたこと、および真空乾燥温度を100℃としたこと以外は実施例2-1と同様にして、負極活物質層の目付けが4mg/cm程度の負極を形成した。
(Example 2-4)
Using a mixture of CMC and SBR (mass ratio: CMC: SBR = 1: 1) instead of PAA as the binder, and using the mass ratio so that the active material: binder = 98: 2. A negative electrode having a negative electrode active material layer weight of about 4 mg / cm 2 was formed in the same manner as in Example 2-1, except that the vacuum drying temperature was 100 ° C.
 正極活物質としてはNCM523を用い、結着剤としてはPVDFを用い、導電助剤としてはABを用いた。正極用集電体としては、厚み20μmのアルミニウム箔を用いた。正極活物質層を100質量部としたときの、正極活物質と導電助剤と結着剤の含有質量比は90:8:2である。これらの正極活物質、導電助剤、結着剤および正極用集電体を用い、実施例2-3と同様にして正極を得た。 NCM523 was used as the positive electrode active material, PVDF was used as the binder, and AB was used as the conductive assistant. As the positive electrode current collector, an aluminum foil having a thickness of 20 μm was used. When the positive electrode active material layer is 100 parts by mass, the mass ratio of the positive electrode active material, the conductive auxiliary agent, and the binder is 90: 8: 2. Using these positive electrode active material, conductive additive, binder and positive electrode current collector, a positive electrode was obtained in the same manner as in Example 2-3.
 上記の正極、負極および上述した電解液E11を用い、実施例2-3と同様にして、実施例2-4の非水電解質二次電池を得た。 Using the above positive electrode, negative electrode and the above-described electrolytic solution E11, a nonaqueous electrolyte secondary battery of Example 2-4 was obtained in the same manner as Example 2-3.
 (比較例2-6)
 電解液E11に代えて電解液C5を用いたこと以外は実施例2-4と同様にして比較例2-6の非水電解質二次電池を得た。
(Comparative Example 2-6)
A nonaqueous electrolyte secondary battery of Comparative Example 2-6 was obtained in the same manner as in Example 2-4 except that the electrolytic solution C5 was used instead of the electrolytic solution E11.
  (評価例33:電池のサイクル耐久性)
 実施例2-4および比較例2-6の非水電解質二次電池を用い、それぞれ温度25℃、1CのCC充電の条件下において4.1Vまで充電し、1分間休止した後、1CのCC放電で3.0Vまで放電し、1分間休止するサイクルを500サイクル繰り返すサイクル試験を行った。500サイクル目における放電容量維持率を測定した結果を表33に示す。放電容量維持率は、500サイクル目の放電容量を初回の放電容量で除した値の百分率{(500サイクル目の放電容量)/(初回の放電容量)×100}で求められる値である。
(Evaluation Example 33: Battery cycle durability)
Using the nonaqueous electrolyte secondary batteries of Example 2-4 and Comparative Example 2-6, charging was performed at a temperature of 25 ° C. and CC charging at 1 C to 4.1 V, and after resting for 1 minute, 1 C CC A cycle test was conducted by repeating 500 cycles of discharging to 3.0 V and resting for 1 minute. Table 33 shows the result of measuring the discharge capacity retention rate at the 500th cycle. The discharge capacity retention ratio is a value obtained by dividing the discharge capacity at the 500th cycle by the initial discharge capacity {(discharge capacity at the 500th cycle) / (initial discharge capacity) × 100}.
 また200サイクル目において温度25℃、0.5CのCCCVで電圧3.5Vに調整した後、3Cで10秒のCC放電をした際の電圧変化量(放電前電圧と放電10秒後電圧との差)および電流値からオームの法則により直流抵抗を測定した。結果を表33に示す。 In addition, after adjusting to a voltage of 3.5 V at a CCCV of 25 ° C. and 0.5 C at the 200th cycle, a voltage change amount when the CC discharge is performed for 10 seconds at 3 C (the voltage before discharge and the voltage after 10 seconds after discharge) DC resistance was measured from the difference) and the current value according to Ohm's law. The results are shown in Table 33.
Figure JPOXMLDOC01-appb-T000033
Figure JPOXMLDOC01-appb-T000033
 実施例2-4のように、親水基を有するポリマーからなる結着剤と本発明に係る本発明の電解液とを組み合わせることで、サイクル寿命が向上するとともに低抵抗の二次電池とすることができる。 As in Example 2-4, combining a binder composed of a polymer having a hydrophilic group and the electrolytic solution of the present invention according to the present invention improves the cycle life and provides a low-resistance secondary battery. Can do.
 (実施例2-5)
 CMC-SBRに代えてPAAを質量比で活物質:結着剤=90:10となるように用いたこと以外は、実施例2-4と同様にして負極を作成し、その負極を用いたこと以外は実施例2-4と同様にして実施例2-5の非水電解質二次電池を得た。
(Example 2-5)
A negative electrode was prepared in the same manner as in Example 2-4, except that PAA was used instead of CMC-SBR so that the mass ratio of active material: binder was 90:10, and the negative electrode was used. A nonaqueous electrolyte secondary battery of Example 2-5 was obtained in the same manner as Example 2-4 except for the above.
  (評価例34:電池の高温貯蔵耐性)
 実施例2-4、2-5、比較例2-6のリチウム二次電池を用い、60℃で1週間貯蔵する高温貯蔵試験を行った。高温貯蔵試験開始前に3.0VからCC-CVで4.1Vにした際の充電容量を基準(SOC100)とし、基準に対し20%分をCC放電(SOC80に調整)した後、高温貯蔵試験を開始した。高温貯蔵試験後に1Cで3.0VまでCC-CVし、この時の放電容量と貯蔵前のSOC80容量の比から、次式のように保存容量を算出した。結果を表34に示す。
 保存容量=100×(貯蔵後のCC-CV放電容量)/(貯蔵前のSOC80容量)
(Evaluation Example 34: High temperature storage resistance of battery)
Using the lithium secondary batteries of Examples 2-4 and 2-5 and Comparative Example 2-6, a high-temperature storage test was performed in which the batteries were stored at 60 ° C. for 1 week. The charge capacity when 3.0V is changed to 4.1V with CC-CV before starting the high-temperature storage test is taken as the standard (SOC100), and 20% of the standard is CC discharged (adjusted to SOC80), and then the high-temperature storage test Started. After the high-temperature storage test, CC-CV was carried out at 1 C to 3.0 V, and the storage capacity was calculated from the ratio of the discharge capacity at this time and the SOC 80 capacity before storage as shown in the following equation. The results are shown in Table 34.
Storage capacity = 100 × (CC-CV discharge capacity after storage) / (SOC 80 capacity before storage)
Figure JPOXMLDOC01-appb-T000034
Figure JPOXMLDOC01-appb-T000034
 実施例2-4、2-5のように、親水基を有するポリマーからなる結着剤と本発明に係る本発明の電解液とを組み合わせることで、高温貯蔵後の容量が向上する。 As in Examples 2-4 and 2-5, the capacity after high-temperature storage is improved by combining the binder composed of a polymer having a hydrophilic group and the electrolytic solution of the present invention according to the present invention.
  (評価例35:電池のサイクル耐久性)
 実施例2-4および比較例2-6の各非水電解質二次電池について、室温、3.0V~4.1V(vs.Li基準)の範囲でCC充放電を500サイクル繰り返し、各サイクルにおける放電電流容量(Ah)および充電電流容量(Ah)を測定した。そして、測定値を基に各サイクルにおけるクーロン効率(%)を算出し、更に、初回充放電時(つまり1サイクル時)から500サイクル時までのクーロン効率の平均値を算出した。また、初回充放電時の放電容量および500サイクル時の放電容量を測定した。そして、初回充放電時の各各非水電解質二次電池の容量を100%とし、500サイクル時の各各非水電解質二次電池の容量維持率(%)を算出した。クーロン効率は{(放電電流容量)/(充電電流容量)}×100に基づいて算出した。結果を表35に示す。
(Evaluation Example 35: Battery cycle durability)
For each non-aqueous electrolyte secondary battery of Example 2-4 and Comparative Example 2-6, CC charge / discharge was repeated 500 cycles at room temperature in the range of 3.0 V to 4.1 V (vs. Li standard). The discharge current capacity (Ah) and the charge current capacity (Ah) were measured. And based on the measured value, the coulomb efficiency (%) in each cycle was computed, and also the average value of the coulomb efficiency from the time of the first charge / discharge (that is, 1 cycle) to 500 cycles was computed. Further, the discharge capacity at the first charge / discharge and the discharge capacity at 500 cycles were measured. And the capacity | capacitance maintenance factor (%) of each nonaqueous electrolyte secondary battery at the time of 500 cycles was computed by making the capacity | capacitance of each nonaqueous electrolyte secondary battery at the time of initial charge / discharge into 100%. Coulomb efficiency was calculated based on {(discharge current capacity) / (charge current capacity)} × 100. The results are shown in Table 35.
Figure JPOXMLDOC01-appb-T000035
Figure JPOXMLDOC01-appb-T000035
 表35に示すように、実施例2-4の非水電解質二次電池は比較例2-6の非水電解質二次電池に比べて、クーロン効率が高く、容量維持率も高い。つまり、金属塩としてのLiFSAと結着剤としてのCMC-SBRとを組み合わせる場合には、金属塩としてのLiPFと結着剤としてのCMC-SBRとを組み合わせる場合に比べて、非水電解質二次電池のサイクル特性を向上させ得る。更に言うと、結着剤として親水基を有するポリマーを用いた本発明の非水電解質二次電池においては、電解液の金属塩としのLiFSAを好ましく用い得る。 As shown in Table 35, the nonaqueous electrolyte secondary battery of Example 2-4 has higher coulomb efficiency and higher capacity retention than the nonaqueous electrolyte secondary battery of Comparative Example 2-6. That is, when LiFSA as a metal salt and CMC-SBR as a binder are combined, compared with a case where LiPF 6 as a metal salt and CMC-SBR as a binder are combined, a non-aqueous electrolyte 2 is used. The cycle characteristics of the secondary battery can be improved. Furthermore, in the nonaqueous electrolyte secondary battery of the present invention using a polymer having a hydrophilic group as a binder, LiFSA as a metal salt of an electrolytic solution can be preferably used.
 なお、クーロン効率は負極における副反応(つまり電解質の分解等、電池反応以外の反応)が低減すると高まる傾向にある。負極における副反応はLiを負極中に不可逆的に捕捉する不可逆反応であることが多く、電池容量低下の原因となり得る。このため、実施例4の各非水電解質二次電池においては上記の副反応が抑制され、その結果、500サイクル時の容量維持率が高まったと推測される。
 参考までに、表35に示すクーロン効率は500サイクルの平均値、つまり、1サイクルあたりの値である。このため、500サイクル分を累積すると、実施例2-4と比較例2-6のクーロン効率の差は非常に大きなものになる。
The Coulomb efficiency tends to increase as side reactions (that is, reactions other than battery reactions such as electrolyte decomposition) in the negative electrode are reduced. The side reaction in the negative electrode is often an irreversible reaction that irreversibly captures Li in the negative electrode, and may cause a reduction in battery capacity. For this reason, in each nonaqueous electrolyte secondary battery of Example 4, said side reaction is suppressed, As a result, it is estimated that the capacity maintenance rate at the time of 500 cycles increased.
For reference, the Coulomb efficiency shown in Table 35 is an average value of 500 cycles, that is, a value per cycle. Therefore, when 500 cycles are accumulated, the difference in coulomb efficiency between Example 2-4 and Comparative Example 2-6 becomes very large.
 (実施例2-6)
 実施例2-4と同じ正極(NCM523:AB:PVdF=90:8:2)および実施例2-1と同じ負極(天然黒鉛:PAA=90:10)を用いたこと以外は実施例2-3と同様にして、実施例2-6の非水電解質二次電池を得た。
(Example 2-6)
Example 2 except that the same positive electrode as in Example 2-4 (NCM523: AB: PVdF = 90: 8: 2) and the same negative electrode as in Example 2-1 (natural graphite: PAA = 90: 10) were used. In the same manner as in Example 3, a nonaqueous electrolyte secondary battery of Example 2-6 was obtained.
 (実施例2-7)
 実施例2-4と同じ正極(NCM523:AB:PVdF=90:8:2)および実施例2-2と同じ負極(天然黒鉛:CMC:SBR=98:1:1)を用いたこと以外は実施例2-3と同様にして、実施例2-7の非水電解質二次電池を得た。
(Example 2-7)
Except that the same positive electrode as in Example 2-4 (NCM523: AB: PVdF = 90: 8: 2) and the same negative electrode as in Example 2-2 (natural graphite: CMC: SBR = 98: 1: 1) were used. A nonaqueous electrolyte secondary battery of Example 2-7 was obtained in the same manner as Example 2-3.
 (比較例2-7)
 電解液C5を用いたこと以外は、実施例2-6と同様の方法で比較例2-7の非水電解質二次電池を得た。
(Comparative Example 2-7)
A nonaqueous electrolyte secondary battery of Comparative Example 2-7 was obtained in the same manner as in Example 2-6 except that the electrolytic solution C5 was used.
 (比較例2-8)
 電解液C5を用いたこと以外は、実施例2-7と同様の方法で比較例2-8の非水電解質二次電池を得た。
(Comparative Example 2-8)
A nonaqueous electrolyte secondary battery of Comparative Example 2-8 was obtained in the same manner as in Example 2-7, except that the electrolytic solution C5 was used.
  (評価例36:電池のサイクル耐久性)
 実施例2-6、2-7の各非水電解質二次電池について、上記の「評価例33:電池のサイクル耐久性」と同様の方法で充放電を200サイクル繰り返し、200サイクル時の各非水電解質二次電池の容量維持率(%)、およびクーロン効率(%、200サイクルの平均値)を算出した。結果を表36に示す。
(Evaluation Example 36: Cycle durability of the battery)
For each of the nonaqueous electrolyte secondary batteries of Examples 2-6 and 2-7, charging / discharging was repeated 200 cycles in the same manner as in the above “Evaluation Example 33: Cycle durability of the battery”. The capacity retention rate (%) and the coulomb efficiency (%, average value of 200 cycles) of the water electrolyte secondary battery were calculated. The results are shown in Table 36.
Figure JPOXMLDOC01-appb-T000036
Figure JPOXMLDOC01-appb-T000036
 表36に示すように、実施例2-6の非水電解質二次電池は、実施例2-7の非水電解質二次電池に比べて、容量維持率およびクーロン効率に優れていた。この結果から、結着剤としてはPAAがより好ましいといえる。 As shown in Table 36, the nonaqueous electrolyte secondary battery of Example 2-6 was superior in capacity retention and coulomb efficiency compared to the nonaqueous electrolyte secondary battery of Example 2-7. From this result, it can be said that PAA is more preferable as the binder.
  (評価例37:電池のサイクル耐久性)
 実施例2-6、2-7および比較例2-7、2-8の各非水電解質二次電池について、上記の「評価例36:電池のサイクル耐久性」と略同様に、203サイクル時の各非水電解質二次電池の容量維持率(%)を算出した。より具体的には、当該試験においては、3サイクル目を試験初期とし、そこから200サイクル充放電をおこなった際の容量維持率を求めた。また、試験初期、つまり3サイクル時において温度25℃、0.5CのCCCVで電圧3.5Vに調整した後、3Cで10秒のCC放電をした際の電圧変化量(放電前電圧と放電10秒後電圧との差)および電流値からオームの法則により直流抵抗を測定した。そして、このときの直流抵抗を初期直流抵抗とした。結果を表37に示す。
(Evaluation Example 37: Battery cycle durability)
The nonaqueous electrolyte secondary batteries of Examples 2-6 and 2-7 and Comparative Examples 2-7 and 2-8 were subjected to 203 cycles in substantially the same manner as in the above “Evaluation Example 36: Battery cycle durability”. The capacity retention rate (%) of each non-aqueous electrolyte secondary battery was calculated. More specifically, in the test, the capacity maintenance rate when charging and discharging for 200 cycles was determined from the third cycle as the initial test. Further, in the initial stage of the test, that is, at a temperature of 25 ° C. at the time of 3 cycles, the voltage change amount when the CC discharge was performed at 3C for 10 seconds after the CCCV of 0.5C was performed (voltage before discharge and discharge 10). The DC resistance was measured from Ohm's law from the difference in voltage after 2 seconds) and the current value. The direct current resistance at this time was used as the initial direct current resistance. The results are shown in Table 37.
Figure JPOXMLDOC01-appb-T000037
Figure JPOXMLDOC01-appb-T000037
 表37に示すように、実施例2-6、実施例2-7、比較例2-7および比較例2-8の各非水電解質二次電池において、203サイクル時の容量維持率は略同程度であり、何れも高い値であった。実施例2-6および2-7を比較すると、結着剤としてはPAAが優れているといえ、比較例2-7および2-8を比較すると、結着剤としてはCMC-SBRが優れているといえる。つまり、本発明の電解液を用いた本発明の非水電解質二次電池においては、結着剤としてCMC-SBRを用いるよりもPAAを用いる方がより好ましいといえる。 As shown in Table 37, in each of the nonaqueous electrolyte secondary batteries of Example 2-6, Example 2-7, Comparative Example 2-7, and Comparative Example 2-8, the capacity retention rate at 203 cycles was substantially the same. All of them were high values. Comparing Examples 2-6 and 2-7, it can be said that PAA is excellent as a binder, and comparing Comparative Examples 2-7 and 2-8, CMC-SBR is excellent as a binder. It can be said that. In other words, in the nonaqueous electrolyte secondary battery of the present invention using the electrolytic solution of the present invention, it can be said that it is more preferable to use PAA than CMC-SBR as a binder.
 なお、金属塩としてLiFSAを用いた実施例2-6および実施例2-7の非水電解質二次電池は、金属塩としてLiPFを用いた比較例2-6および比較例2-7の非水電解質二次電池に比べて、初期直流抵抗が低い。したがって、容量維持率の向上と抵抗増大の抑制とを両立させるためには、本発明の電解液を用いかつ結着剤として親水基を有する結着剤を用いた実施例2-6および実施例2-7の非水電解質二次電池、つまり、本発明の非水電解質二次電池が有利だといえる。 Note that the non-aqueous electrolyte secondary batteries of Examples 2-6 and 2-7 using LiFSA as the metal salt are the same as those of Comparative Examples 2-6 and 2-7 using LiPF 6 as the metal salt. Compared with a water electrolyte secondary battery, the initial DC resistance is low. Therefore, in order to achieve both improvement in capacity retention rate and suppression of increase in resistance, Examples 2-6 and Examples using the electrolytic solution of the present invention and a binder having a hydrophilic group as the binder are used. It can be said that the 2-7 nonaqueous electrolyte secondary battery, that is, the nonaqueous electrolyte secondary battery of the present invention is advantageous.
  (評価例38:電池の高温貯蔵耐性)
 実施例2-6、2-7、比較例2-7、2-8の非水電解質二次電池を用い、60℃で1週間貯蔵する高温貯蔵試験を行った。高温貯蔵試験開始前に3.0VからCC-CVで4.1Vにした際の充電容量を基準、つまり、SOC100とした。そして、基準に対し20%分をCC放電してSOC80に調整した後、高温貯蔵試験を開始した。高温貯蔵試験後に1Cで3.0VまでCC-CVし、この時の放電容量と貯蔵前のSOC80容量の比を基にして、次式のように残存容量を算出した。
 残存容量=100×(貯蔵後のCC-CV放電容量)/(貯蔵前のSOC80容量)
保存容量を算出した。結果を表38に示す。
(Evaluation Example 38: Resistance to high-temperature storage of batteries)
Using the nonaqueous electrolyte secondary batteries of Examples 2-6 and 2-7 and Comparative Examples 2-7 and 2-8, a high-temperature storage test was performed in which the batteries were stored at 60 ° C. for 1 week. Prior to the start of the high-temperature storage test, the charging capacity when 3.0V was changed to 4.1V by CC-CV was set as a reference, that is, SOC100. Then, 20% of the standard was CC discharged and adjusted to SOC 80, and then a high temperature storage test was started. After the high-temperature storage test, CC-CV was performed at 1 C to 3.0 V, and the remaining capacity was calculated according to the following formula based on the ratio of the discharge capacity at this time and the SOC 80 capacity before storage.
Remaining capacity = 100 × (CC-CV discharge capacity after storage) / (SOC 80 capacity before storage)
The storage capacity was calculated. The results are shown in Table 38.
Figure JPOXMLDOC01-appb-T000038
Figure JPOXMLDOC01-appb-T000038
 表38に示すように、実施例2-6の非水電解質二次電池は、実施例2-7の非水電解質二次電池に比べて残存容量が大きかった。つまり、LiFSA/ANとPAAを組み合わせた実施例2-6の非水電解質二次電池は、LiFSA/ANとCMC-SBRとを組み合わせた実施例2-7の非水電解質二次電池に比べて、高温貯蔵特性に優れていた。また、この結果から、本発明の電解液と親水基を有するポリマーからなる結着剤とを組み合わせた本発明の非水電解質二次電池は、通常の電解液と親水基を有するポリマーからなる結着剤とを組み合わせた従来の非水電解質二次電池と同等または同等以上の高温貯蔵耐性を有することがわかる。 As shown in Table 38, the non-aqueous electrolyte secondary battery of Example 2-6 had a larger remaining capacity than the non-aqueous electrolyte secondary battery of Example 2-7. That is, the non-aqueous electrolyte secondary battery of Example 2-6 that combines LiFSA / AN and PAA is compared with the non-aqueous electrolyte secondary battery of Example 2-7 that combines LiFSA / AN and CMC-SBR. It was excellent in high-temperature storage characteristics. Further, from this result, the non-aqueous electrolyte secondary battery of the present invention in which the electrolytic solution of the present invention and the binder composed of a polymer having a hydrophilic group are combined is a binder composed of a normal electrolytic solution and a polymer having a hydrophilic group. It can be seen that it has a high temperature storage resistance equivalent to or higher than that of a conventional non-aqueous electrolyte secondary battery combined with an adhesive.
(その他の態様II)
 本発明の電解液として、以下の電解液を具体的に挙げる。なお、以下の電解液には、既述のものも含まれている。
(Other aspects II)
Specific examples of the electrolytic solution of the present invention include the following electrolytic solutions. The following electrolytes include those already described.
 (電解液A)
 本発明の電解液を以下のとおり製造した。
 有機溶媒である1,2-ジメトキシエタン約5mLを、撹拌子および温度計を備えたフラスコに入れた。撹拌条件下にて、上記フラスコ中の1,2-ジメトキシエタンに対し、リチウム塩である(CFSONLiを溶液温度が40℃以下を保つように徐々に加え、溶解させた。約13gの(CFSONLiを加えた時点で(CFSONLiの溶解が一時停滞したので、上記フラスコを恒温槽に投入し、フラスコ内の溶液温度が50℃となるよう加温し、(CFSONLiを溶解させた。約15gの(CFSONLiを加えた時点で(CFSONLiの溶解が再び停滞したので、1,2-ジメトキシエタンをピペットで1滴加えたところ、(CFSONLiは溶解した。さらに(CFSONLiを徐々に加え、所定の(CFSONLiを全量加えた。得られた電解液を20mLメスフラスコに移し、容積が20mLとなるまで1,2-ジメトキシエタンを加えた。得られた電解液は容積20mLであり、この電解液に含まれる(CFSONLiは18.38gであった。これを電解液Aとした。電解液Aにおける(CFSONLiの濃度は3.2mol/Lであり、密度は1.39g/cmであった。密度は20℃で測定した。
 なお、上記製造は不活性ガス雰囲気下のグローブボックス内で行った。
(Electrolytic solution A)
The electrolytic solution of the present invention was produced as follows.
About 5 mL of 1,2-dimethoxyethane, an organic solvent, was placed in a flask equipped with a stir bar and a thermometer. Under stirring conditions, (CF 3 SO 2 ) 2 NLi, which is a lithium salt, was gradually added to 1,2-dimethoxyethane in the flask so as to keep the solution temperature at 40 ° C. or lower and dissolved. When about 13 g of (CF 3 SO 2 ) 2 NLi was added, the dissolution of (CF 3 SO 2 ) 2 NLi temporarily stagnated. Therefore, the flask was put into a thermostat, and the solution temperature in the flask was 50 ° C. (CF 3 SO 2 ) 2 NLi was dissolved. When about 15 g of (CF 3 SO 2 ) 2 NLi was added, the dissolution of (CF 3 SO 2 ) 2 NLi stagnated again, so 1 drop of 1,2-dimethoxyethane was added with a pipette (CF 3 SO 2 ) 2 NLi dissolved. Further, (CF 3 SO 2 ) 2 NLi was gradually added, and the entire amount of predetermined (CF 3 SO 2 ) 2 NLi was added. The resulting electrolyte was transferred to a 20 mL volumetric flask and 1,2-dimethoxyethane was added until the volume was 20 mL. The obtained electrolytic solution had a volume of 20 mL, and (CF 3 SO 2 ) 2 NLi contained in this electrolytic solution was 18.38 g. This was designated as an electrolytic solution A. The concentration of (CF 3 SO 2 ) 2 NLi in the electrolytic solution A was 3.2 mol / L, and the density was 1.39 g / cm 3 . The density was measured at 20 ° C.
The production was performed in a glove box under an inert gas atmosphere.
 (電解液B)
 電解液Aと同様の方法で、(CFSONLiの濃度が2.8mol/Lであり、密度が1.36g/cmである、電解液Bを製造した。
(Electrolytic solution B)
By a method similar to that for the electrolytic solution A, an electrolytic solution B having a (CF 3 SO 2 ) 2 NLi concentration of 2.8 mol / L and a density of 1.36 g / cm 3 was produced.
 (電解液C)
 有機溶媒であるアセトニトリル約5mLを、撹拌子を備えたフラスコに入れた。撹拌条件下にて、上記フラスコ中のアセトニトリルに対し、リチウム塩である(CFSONLiを徐々に加え、溶解させた。所定の(CFSONLiを加えたところで一晩撹拌した。得られた電解液を20mLメスフラスコに移し、容積が20mLとなるまでアセトニトリルを加えた。これを電解液Cとした。なお、上記製造は不活性ガス雰囲気下のグローブボックス内で行った。
 電解液Cは、(CFSONLiの濃度が4.2mol/Lであり、密度が1.52g/cmであった。
(Electrolytic solution C)
About 5 mL of acetonitrile, which is an organic solvent, was placed in a flask equipped with a stir bar. Under stirring conditions, (CF 3 SO 2 ) 2 NLi, which is a lithium salt, was gradually added to and dissolved in acetonitrile in the flask. The mixture was stirred overnight when the prescribed (CF 3 SO 2 ) 2 NLi was added. The resulting electrolyte was transferred to a 20 mL volumetric flask and acetonitrile was added until the volume was 20 mL. This was designated as an electrolytic solution C. The production was performed in a glove box under an inert gas atmosphere.
The electrolytic solution C had a (CF 3 SO 2 ) 2 NLi concentration of 4.2 mol / L and a density of 1.52 g / cm 3 .
 (電解液D)
 電解液Cと同様の方法で、(CFSONLiの濃度が3.0mol/Lであり、密度が1.31g/cmである、電解液Dを製造した。
(Electrolyte D)
By a method similar to that of the electrolytic solution C, an electrolytic solution D having a concentration of (CF 3 SO 2 ) 2 NLi of 3.0 mol / L and a density of 1.31 g / cm 3 was produced.
 (電解液E)
 有機溶媒としてスルホランを用いた以外は、電解液Cと同様の方法で、(CFSONLiの濃度が3.0mol/Lであり、密度が1.57g/cmである、電解液Eを製造した。
(Electrolyte E)
Except for using sulfolane as the organic solvent, in the same manner as the electrolytic solution C, the concentration of (CF 3 SO 2 ) 2 NLi is 3.0 mol / L and the density is 1.57 g / cm 3. Liquid E was produced.
 (電解液F)
 有機溶媒としてジメチルスルホキシドを用いた以外は、電解液Cと同様の方法で、(CFSONLiの濃度が3.2mol/Lであり、密度が1.49g/cmである、電解液Fを製造した。
(Electrolyte F)
The concentration of (CF 3 SO 2 ) 2 NLi is 3.2 mol / L and the density is 1.49 g / cm 3 except that dimethyl sulfoxide is used as the organic solvent. Electrolytic solution F was produced.
 (電解液G)
 リチウム塩として(FSONLiを用い、有機溶媒として1,2-ジメトキシエタンを用いた以外は、電解液Cと同様の方法で、(FSONLiの濃度が4.0mol/Lであり、密度が1.33g/cmである、電解液Gを製造した。
(Electrolyte G)
The concentration of (FSO 2 ) 2 NLi is 4.0 mol / L in the same manner as in the electrolytic solution C, except that (FSO 2 ) 2 NLi is used as the lithium salt and 1,2-dimethoxyethane is used as the organic solvent. An electrolyte solution G having a density of 1.33 g / cm 3 was produced.
 (電解液H)
 電解液Gと同様の方法で、(FSONLiの濃度が3.6mol/Lであり、密度が1.29g/cmである、電解液Hを製造した。
(Electrolyte H)
In the same manner as the electrolytic solution G, an electrolytic solution H having a concentration of (FSO 2 ) 2 NLi of 3.6 mol / L and a density of 1.29 g / cm 3 was produced.
 (電解液I)
 電解液Gと同様の方法で、(FSONLiの濃度が2.4mol/Lであり、密度が1.18g/cmである、電解液Iを製造した。
(Electrolyte I)
In the same manner as the electrolytic solution G, an electrolytic solution I having a concentration of (FSO 2 ) 2 NLi of 2.4 mol / L and a density of 1.18 g / cm 3 was produced.
 (電解液J)
 有機溶媒としてアセトニトリルを用いた以外は、電解液Gと同様の方法で、(FSONLiの濃度が5.0mol/Lであり、密度が1.40g/cmである、電解液Jを製造した。
(Electrolytic solution J)
Except that acetonitrile was used as the organic solvent, an electrolytic solution J having a concentration of (FSO 2 ) 2 NLi of 5.0 mol / L and a density of 1.40 g / cm 3 in the same manner as the electrolytic solution G Manufactured.
 (電解液K)
 電解液Jと同様の方法で、(FSONLiの濃度が4.5mol/Lであり、密度が1.34g/cmである、電解液Kを製造した。
(Electrolytic solution K)
In the same manner as the electrolytic solution J, an electrolytic solution K having a concentration of (FSO 2 ) 2 NLi of 4.5 mol / L and a density of 1.34 g / cm 3 was produced.
 (電解液L)
 有機溶媒であるジメチルカーボネート約5mLを、撹拌子を備えたフラスコに入れた。撹拌条件下にて、上記フラスコ中のジメチルカーボネートに対し、リチウム塩である(FSONLiを徐々に加え、溶解させた。(FSONLiを全量で14.64g加えたところで一晩撹拌した。得られた電解液を20mLメスフラスコに移し、容積が20mLとなるまでジメチルカーボネートを加えた。これを電解液Lとした。なお、上記製造は不活性ガス雰囲気下のグローブボックス内で行った。
 電解液Lにおける(FSONLiの濃度は3.9mol/Lであり、電解液Lの密度は1.44g/cmであった。
(Electrolytic solution L)
About 5 mL of dimethyl carbonate, which is an organic solvent, was placed in a flask equipped with a stir bar. Under stirring conditions, (FSO 2 ) 2 NLi, which is a lithium salt, was gradually added to dimethyl carbonate in the flask and dissolved. When (FSO 2 ) 2 NLi was added in a total amount of 14.64 g, the mixture was stirred overnight. The resulting electrolyte was transferred to a 20 mL volumetric flask and dimethyl carbonate was added until the volume was 20 mL. This was designated as an electrolytic solution L. The production was performed in a glove box under an inert gas atmosphere.
The concentration of (FSO 2 ) 2 NLi in the electrolytic solution L was 3.9 mol / L, and the density of the electrolytic solution L was 1.44 g / cm 3 .
 (電解液M)
 電解液Lと同様の方法で、(FSONLiの濃度が2.9mol/Lであり、密度が1.36g/cmである、電解液Mを製造した。
(Electrolyte M)
In the same manner as the electrolytic solution L, an electrolytic solution M having a (FSO 2 ) 2 NLi concentration of 2.9 mol / L and a density of 1.36 g / cm 3 was produced.
 (電解液N)
 有機溶媒であるエチルメチルカーボネート約5mLを、撹拌子を備えたフラスコに入れた。撹拌条件下にて、上記フラスコ中のエチルメチルカーボネートに対し、リチウム塩である(FSONLiを徐々に加え、溶解させた。(FSONLiを全量で12.81g加えたところで一晩撹拌した。得られた電解液を20mLメスフラスコに移し、容積が20mLとなるまでエチルメチルカーボネートを加えた。これを電解液Nとした。なお、上記製造は不活性ガス雰囲気下のグローブボックス内で行った。
 電解液Nにおける(FSONLiの濃度は3.4mol/Lであり、電解液Nの密度は1.35g/cmであった。
(Electrolytic solution N)
About 5 mL of ethyl methyl carbonate, which is an organic solvent, was placed in a flask equipped with a stir bar. Under stirring conditions, (FSO 2 ) 2 NLi, which is a lithium salt, was gradually added to and dissolved in ethyl methyl carbonate in the flask. When 12.81 g of (FSO 2 ) 2 NLi was added in total, the mixture was stirred overnight. The obtained electrolytic solution was transferred to a 20 mL volumetric flask, and ethyl methyl carbonate was added until the volume became 20 mL. This was designated as an electrolytic solution N. The production was performed in a glove box under an inert gas atmosphere.
The concentration of (FSO 2 ) 2 NLi in the electrolytic solution N was 3.4 mol / L, and the density of the electrolytic solution N was 1.35 g / cm 3 .
 (電解液O)
 有機溶媒であるジエチルカーボネート約5mLを、撹拌子を備えたフラスコに入れた。撹拌条件下にて、上記フラスコ中のジエチルカーボネートに対し、リチウム塩である(FSONLiを徐々に加え、溶解させた。(FSONLiを全量で11.37g加えたところで一晩撹拌した。得られた電解液を20mLメスフラスコに移し、容積が20mLとなるまでジエチルカーボネートを加えた。これを電解液Oとした。なお、上記製造は不活性ガス雰囲気下のグローブボックス内で行った。
 電解液Oにおける(FSONLiの濃度は3.0mol/Lであり、電解液Oの密度は1.29g/cmであった。
(Electrolytic solution O)
About 5 mL of diethyl carbonate, which is an organic solvent, was placed in a flask equipped with a stirring bar. Under stirring conditions, (FSO 2 ) 2 NLi, which is a lithium salt, was gradually added to and dissolved in diethyl carbonate in the flask. When 11.37 g of the total amount of (FSO 2 ) 2 NLi was added, the mixture was stirred overnight. The resulting electrolyte was transferred to a 20 mL volumetric flask and diethyl carbonate was added until the volume was 20 mL. This was designated as an electrolytic solution O. The production was performed in a glove box under an inert gas atmosphere.
The concentration of (FSO 2 ) 2 NLi in the electrolytic solution O was 3.0 mol / L, and the density of the electrolytic solution O was 1.29 g / cm 3 .
 表39に上記電解液の一覧を示す。 Table 39 shows a list of the above electrolytes.
Figure JPOXMLDOC01-appb-T000039
Figure JPOXMLDOC01-appb-T000039
Figure JPOXMLDOC01-appb-T000040
Figure JPOXMLDOC01-appb-T000040

Claims (24)

  1.  負極と電解液と正極とを含み、
     前記電解液は、アルカリ金属、アルカリ土類金属またはアルミニウムをカチオンとするとともにアニオンの化学構造に硫黄元素および酸素元素を含む塩と、ヘテロ元素を有する有機溶媒とを含み、
     前記電解液の振動分光スペクトルにおける前記有機溶媒由来のピーク強度につき、前記有機溶媒本来のピークの強度をIoとし、前記ピークがシフトしたピークの強度をIsとした場合、Is>Ioであり、
     前記負極の表面に、S=O構造を有するS,O含有皮膜が形成されている非水電解質二次電池。
    Including a negative electrode, an electrolyte and a positive electrode,
    The electrolytic solution includes a salt containing an alkali metal, an alkaline earth metal or aluminum as a cation and containing a sulfur element and an oxygen element in the chemical structure of an anion, and an organic solvent having a hetero element,
    Regarding the peak intensity derived from the organic solvent in the vibrational spectrum of the electrolyte solution, when the intensity of the original peak of the organic solvent is Io and the intensity of the peak shifted from the peak is Is, Is> Io,
    A nonaqueous electrolyte secondary battery in which an S, O-containing film having an S = O structure is formed on the surface of the negative electrode.
  2.  負極と電解液と正極とを含み、
     前記電解液は、アルカリ金属、アルカリ土類金属またはアルミニウムをカチオンとするとともにアニオンの化学構造に硫黄元素および酸素元素を含む塩と、ヘテロ元素を有する有機溶媒とを含み、
     前記電解液の振動分光スペクトルにおける前記有機溶媒由来のピーク強度につき、前記有機溶媒本来のピークの強度をIoとし、前記ピークがシフトしたピークの強度をIsとした場合、Is>Ioであり、
     前記負極の表面および前記正極の表面のうちの少なくとも前記正極の表面に、S=O構造を有するS,O含有皮膜が形成されている非水電解質二次電池。
    Including a negative electrode, an electrolyte and a positive electrode,
    The electrolytic solution includes a salt containing an alkali metal, an alkaline earth metal or aluminum as a cation and containing a sulfur element and an oxygen element in the chemical structure of an anion, and an organic solvent having a hetero element,
    Regarding the peak intensity derived from the organic solvent in the vibrational spectrum of the electrolyte solution, when the intensity of the original peak of the organic solvent is Io and the intensity of the peak shifted from the peak is Is, Is> Io,
    A non-aqueous electrolyte secondary battery in which an S, O-containing film having an S = O structure is formed on at least the positive electrode surface of the negative electrode surface and the positive electrode surface.
  3.  前記負極は、負極活物質に炭素元素を含む請求項1または2に記載の非水電解質二次電池。 The non-aqueous electrolyte secondary battery according to claim 1, wherein the negative electrode includes a carbon element in a negative electrode active material.
  4.  前記塩のアニオンの化学構造が下記一般式(1)、一般式(2)または一般式(3)で表される請求項1~3の何れか一項に記載の非水電解質二次電池。
      (R)(R)N・・・・・・一般式(1)
    (Rは、水素、ハロゲン、置換基で置換されていても良いアルキル基、置換基で置換されていても良いシクロアルキル基、置換基で置換されていても良い不飽和アルキル基、置換基で置換されていても良い不飽和シクロアルキル基、置換基で置換されていても良い芳香族基、置換基で置換されていても良い複素環基、置換基で置換されていても良いアルコキシ基、置換基で置換されていても良い不飽和アルコキシ基、置換基で置換されていても良いチオアルコキシ基、置換基で置換されていても良い不飽和チオアルコキシ基、CN、SCN、OCNから選択される。
     Rは、水素、ハロゲン、置換基で置換されていても良いアルキル基、置換基で置換されていても良いシクロアルキル基、置換基で置換されていても良い不飽和アルキル基、置換基で置換されていても良い不飽和シクロアルキル基、置換基で置換されていても良い芳香族基、置換基で置換されていても良い複素環基、置換基で置換されていても良いアルコキシ基、置換基で置換されていても良い不飽和アルコキシ基、置換基で置換されていても良いチオアルコキシ基、置換基で置換されていても良い不飽和チオアルコキシ基、CN、SCN、OCNから選択される。
     また、RとRは、互いに結合して環を形成しても良い。
     Xは、SO、S=Oから選択される。
     Xは、SO、S=Oから選択される。)
      RY・・・・・・一般式(2)
    (Rは、水素、ハロゲン、置換基で置換されていても良いアルキル基、置換基で置換されていても良いシクロアルキル基、置換基で置換されていても良い不飽和アルキル基、置換基で置換されていても良い不飽和シクロアルキル基、置換基で置換されていても良い芳香族基、置換基で置換されていても良い複素環基、置換基で置換されていても良いアルコキシ基、置換基で置換されていても良い不飽和アルコキシ基、置換基で置換されていても良いチオアルコキシ基、置換基で置換されていても良い不飽和チオアルコキシ基、CN、SCN、OCNから選択される。
     Xは、SO、S=Oから選択される。
     Yは、O、Sから選択される。)
      (R)(R)(R)C・・・・・・一般式(3)
    (Rは、水素、ハロゲン、置換基で置換されていても良いアルキル基、置換基で置換されていても良いシクロアルキル基、置換基で置換されていても良い不飽和アルキル基、置換基で置換されていても良い不飽和シクロアルキル基、置換基で置換されていても良い芳香族基、置換基で置換されていても良い複素環基、置換基で置換されていても良いアルコキシ基、置換基で置換されていても良い不飽和アルコキシ基、置換基で置換されていても良いチオアルコキシ基、置換基で置換されていても良い不飽和チオアルコキシ基、CN、SCN、OCNから選択される。
     Rは、水素、ハロゲン、置換基で置換されていても良いアルキル基、置換基で置換されていても良いシクロアルキル基、置換基で置換されていても良い不飽和アルキル基、置換基で置換されていても良い不飽和シクロアルキル基、置換基で置換されていても良い芳香族基、置換基で置換されていても良い複素環基、置換基で置換されていても良いアルコキシ基、置換基で置換されていても良い不飽和アルコキシ基、置換基で置換されていても良いチオアルコキシ基、置換基で置換されていても良い不飽和チオアルコキシ基、CN、SCN、OCNから選択される。
     Rは、水素、ハロゲン、置換基で置換されていても良いアルキル基、置換基で置換されていても良いシクロアルキル基、置換基で置換されていても良い不飽和アルキル基、置換基で置換されていても良い不飽和シクロアルキル基、置換基で置換されていても良い芳香族基、置換基で置換されていても良い複素環基、置換基で置換されていても良いアルコキシ基、置換基で置換されていても良い不飽和アルコキシ基、置換基で置換されていても良いチオアルコキシ基、置換基で置換されていても良い不飽和チオアルコキシ基、CN、SCN、OCNから選択される。
     また、R、R、Rのうち、いずれか2つまたは3つが結合して環を形成しても良い。
     Xは、SO、S=Oから選択される。
     Xは、SO、S=Oから選択される。
     Xは、SO、S=Oから選択される。)
    The nonaqueous electrolyte secondary battery according to any one of claims 1 to 3, wherein the chemical structure of the anion of the salt is represented by the following general formula (1), general formula (2), or general formula (3).
    (R 1 X 1 ) (R 2 X 2 ) N... General formula (1)
    (R 1 is hydrogen, halogen, an alkyl group which may be substituted with a substituent, a cycloalkyl group which may be substituted with a substituent, an unsaturated alkyl group which may be substituted with a substituent, or a substituent. An unsaturated cycloalkyl group which may be substituted with, an aromatic group which may be substituted with a substituent, a heterocyclic group which may be substituted with a substituent, or an alkoxy group which may be substituted with a substituent , An unsaturated alkoxy group that may be substituted with a substituent, a thioalkoxy group that may be substituted with a substituent, an unsaturated thioalkoxy group that may be substituted with a substituent, CN, SCN, or OCN Is done.
    R 2 represents hydrogen, halogen, an alkyl group which may be substituted with a substituent, a cycloalkyl group which may be substituted with a substituent, an unsaturated alkyl group which may be substituted with a substituent, or a substituent. An unsaturated cycloalkyl group which may be substituted, an aromatic group which may be substituted with a substituent, a heterocyclic group which may be substituted with a substituent, an alkoxy group which may be substituted with a substituent, Selected from an unsaturated alkoxy group which may be substituted with a substituent, a thioalkoxy group which may be substituted with a substituent, an unsaturated thioalkoxy group which may be substituted with a substituent, CN, SCN, OCN The
    R 1 and R 2 may be bonded to each other to form a ring.
    X 1 is selected from SO 2 and S═O.
    X 2 is selected from SO 2 and S═O. )
    R 3 X 3 Y: General formula (2)
    (R 3 is hydrogen, halogen, an alkyl group which may be substituted with a substituent, a cycloalkyl group which may be substituted with a substituent, an unsaturated alkyl group which may be substituted with a substituent, or a substituent. An unsaturated cycloalkyl group which may be substituted with, an aromatic group which may be substituted with a substituent, a heterocyclic group which may be substituted with a substituent, or an alkoxy group which may be substituted with a substituent , An unsaturated alkoxy group that may be substituted with a substituent, a thioalkoxy group that may be substituted with a substituent, an unsaturated thioalkoxy group that may be substituted with a substituent, CN, SCN, or OCN Is done.
    X 3 is selected from SO 2 and S═O.
    Y is selected from O and S. )
    (R 4 X 4 ) (R 5 X 5 ) (R 6 X 6 ) C ... General formula (3)
    (R 4 is hydrogen, halogen, an alkyl group which may be substituted with a substituent, a cycloalkyl group which may be substituted with a substituent, an unsaturated alkyl group which may be substituted with a substituent, or a substituent. An unsaturated cycloalkyl group which may be substituted with, an aromatic group which may be substituted with a substituent, a heterocyclic group which may be substituted with a substituent, or an alkoxy group which may be substituted with a substituent , An unsaturated alkoxy group that may be substituted with a substituent, a thioalkoxy group that may be substituted with a substituent, an unsaturated thioalkoxy group that may be substituted with a substituent, CN, SCN, or OCN Is done.
    R 5 represents hydrogen, halogen, an alkyl group which may be substituted with a substituent, a cycloalkyl group which may be substituted with a substituent, an unsaturated alkyl group which may be substituted with a substituent, or a substituent. An unsaturated cycloalkyl group which may be substituted, an aromatic group which may be substituted with a substituent, a heterocyclic group which may be substituted with a substituent, an alkoxy group which may be substituted with a substituent, Selected from an unsaturated alkoxy group which may be substituted with a substituent, a thioalkoxy group which may be substituted with a substituent, an unsaturated thioalkoxy group which may be substituted with a substituent, CN, SCN, OCN The
    R 6 is hydrogen, halogen, an alkyl group which may be substituted with a substituent, a cycloalkyl group which may be substituted with a substituent, an unsaturated alkyl group which may be substituted with a substituent, or a substituent. An unsaturated cycloalkyl group which may be substituted, an aromatic group which may be substituted with a substituent, a heterocyclic group which may be substituted with a substituent, an alkoxy group which may be substituted with a substituent, Selected from an unsaturated alkoxy group which may be substituted with a substituent, a thioalkoxy group which may be substituted with a substituent, an unsaturated thioalkoxy group which may be substituted with a substituent, CN, SCN, OCN The
    Further, any two or three of R 4 , R 5 and R 6 may be bonded to form a ring.
    X 4 is selected from SO 2 and S═O.
    X 5 is selected from SO 2 and S═O.
    X 6 is selected from SO 2 and S═O. )
  5.  前記塩のアニオンの化学構造が下記一般式(4)、一般式(5)または一般式(6)で表される請求項1~4の何れか一項に記載の非水電解質二次電池。
      (R)(R)N・・・・・・一般式(4)
    (R、Rは、それぞれ独立に、CClBr(CN)(SCN)(OCN)である。
     n、a、b、c、d、e、f、g、hはそれぞれ独立に0以上の整数であり、2n+1=a+b+c+d+e+f+g+hを満たす。
     また、RとRは、互いに結合して環を形成しても良く、その場合は、2n=a+b+c+d+e+f+g+hを満たす。
     Xは、SO、S=Oから選択される。
     Xは、SO、S=Oから選択される。)
      RY・・・・・・一般式(5)
    (Rは、CClBr(CN)(SCN)(OCN)である。
     n、a、b、c、d、e、f、g、hはそれぞれ独立に0以上の整数であり、2n+1=a+b+c+d+e+f+g+hを満たす。
     Xは、SO、S=Oから選択される。
     Yは、O、Sから選択される。)
      (R1010)(R1111)(R1212)C・・・一般式(6)
    (R10、R11、R12は、それぞれ独立に、CClBr(CN)(SCN)(OCN)である。
     n、a、b、c、d、e、f、g、hはそれぞれ独立に0以上の整数であり、2n+1=a+b+c+d+e+f+g+hを満たす。
     R10、R11、R12のうちいずれか2つが結合して環を形成しても良く、その場合、環を形成する基は2n=a+b+c+d+e+f+g+hを満たす。また、R10、R11、R12の3つが結合して環を形成しても良く、その場合、3つのうち2つの基が2n=a+b+c+d+e+f+g+hを満たし、1つの基が2n-1=a+b+c+d+e+f+g+hを満たす。
     X10は、SO、S=Oから選択される。
     X11は、SO、S=Oから選択される。
     X12は、SO、S=Oから選択される。)
    The nonaqueous electrolyte secondary battery according to any one of claims 1 to 4, wherein a chemical structure of the anion of the salt is represented by the following general formula (4), general formula (5), or general formula (6).
    (R 7 X 7 ) (R 8 X 8 ) N ... General formula (4)
    (R 7 and R 8 are each independently C n H a F b Cl c Br d I e (CN) f (SCN) g (OCN) h .
    n, a, b, c, d, e, f, g, and h are each independently an integer of 0 or more, and satisfy 2n + 1 = a + b + c + d + e + f + g + h.
    R 7 and R 8 may combine with each other to form a ring, in which case 2n = a + b + c + d + e + f + g + h is satisfied.
    X 7 is selected from SO 2 and S═O.
    X 8 is selected from SO 2 and S═O. )
    R 9 X 9 Y: General formula (5)
    (R 9 is a C n H a F b Cl c Br d I e (CN) f (SCN) g (OCN) h.
    n, a, b, c, d, e, f, g, and h are each independently an integer of 0 or more, and satisfy 2n + 1 = a + b + c + d + e + f + g + h.
    X 9 is selected from SO 2 and S═O.
    Y is selected from O and S. )
    (R 10 X 10) (R 11 X 11) (R 12 X 12) C ··· formula (6)
    (R 10 , R 11 , and R 12 are each independently C n H a F b Cl c Br d I e (CN) f (SCN) g (OCN) h .
    n, a, b, c, d, e, f, g, and h are each independently an integer of 0 or more, and satisfy 2n + 1 = a + b + c + d + e + f + g + h.
    Any two of R 10 , R 11 , and R 12 may combine to form a ring, in which case the group forming the ring satisfies 2n = a + b + c + d + e + f + g + h. Further, three of R 10 , R 11 and R 12 may combine to form a ring, in which case two groups out of the three satisfy 2n = a + b + c + d + e + f + g + h, and one group satisfies 2n−1 = a + b + c + d + e + f + g + h. Fulfill.
    X 10 is selected from SO 2 and S═O.
    X 11 is selected from SO 2 and S═O.
    X 12 is selected from SO 2 and S═O. )
  6.  前記正極は、アルミニウムまたはアルミニウム合金からなる正極用集電体を有する請求項1~5の何れか一項に記載の非水電解質二次電池。 The non-aqueous electrolyte secondary battery according to any one of claims 1 to 5, wherein the positive electrode has a positive electrode current collector made of aluminum or an aluminum alloy.
  7.  前記S,O含有皮膜のS濃度およびO濃度は、充放電で変化する請求項1~6の何れか一項に記載の非水電解質二次電池。 The non-aqueous electrolyte secondary battery according to any one of claims 1 to 6, wherein the S concentration and the O concentration of the S, O-containing coating change by charging and discharging.
  8.  前記S,O含有皮膜の厚さは、充放電で変化する請求項1~7の何れか一項に記載の非水電解質二次電池。 The non-aqueous electrolyte secondary battery according to any one of claims 1 to 7, wherein the thickness of the S, O-containing coating changes by charging and discharging.
  9.  前記S,O含有皮膜は、2原子%以上のSを含む請求項1~8の何れか一項に記載の非水電解質二次電池。 The nonaqueous electrolyte secondary battery according to any one of claims 1 to 8, wherein the S, O-containing coating contains 2 atomic% or more of S.
  10.  アルカリ金属、アルカリ土類金属またはアルミニウムをカチオンとする塩と、ヘテロ元素を有する有機溶媒とを含み、振動分光スペクトルにおける前記有機溶媒由来のピーク強度につき、前記有機溶媒本来のピークの強度をIoとし、前記ピークがシフトしたピークの強度をIsとした場合、Is>Ioである電解液と、
     親水基を有するポリマーからなる結着剤を含む負極活物質層をもつ負極と、を具備することを特徴とする非水電解質二次電池。
    Including a salt having alkali metal, alkaline earth metal or aluminum as a cation and an organic solvent having a hetero element, the peak intensity derived from the organic solvent in a vibrational spectrum is defined as Io. An electrolyte solution with Is> Io, where Is is the intensity of the peak shifted from the peak,
    A non-aqueous electrolyte secondary battery comprising: a negative electrode having a negative electrode active material layer containing a binder made of a polymer having a hydrophilic group.
  11.  前記親水基を有するポリマーは、一分子中に複数のカルボキシル基および/またはスルホ基を含む請求項10に記載の非水電解質二次電池。 The non-aqueous electrolyte secondary battery according to claim 10, wherein the polymer having a hydrophilic group includes a plurality of carboxyl groups and / or sulfo groups in one molecule.
  12.  前記親水基を有するポリマーは水溶性ポリマーである請求項10または11に記載の非水電解質二次電池。 The non-aqueous electrolyte secondary battery according to claim 10 or 11, wherein the polymer having a hydrophilic group is a water-soluble polymer.
  13.  前記水溶性ポリマーは、一分子中に複数のカルボキシル基および/またはスルホ基を含む請求項12に記載の非水電解質二次電池。 The non-aqueous electrolyte secondary battery according to claim 12, wherein the water-soluble polymer contains a plurality of carboxyl groups and / or sulfo groups in one molecule.
  14.  前記電解液は、前記塩のアニオンの化学構造が、ハロゲン、ホウ素、窒素、酸素、硫黄または炭素から選択される少なくとも1つの元素を含む請求項10~13の何れか一項に記載の非水電解質二次電池。 The non-aqueous solution according to any one of claims 10 to 13, wherein the electrolytic solution contains at least one element selected from halogen, boron, nitrogen, oxygen, sulfur or carbon, in the chemical structure of the anion of the salt. Electrolyte secondary battery.
  15.  前記電解液は、前記塩のアニオンの化学構造が下記一般式(1)、一般式(2)または一般式(3)で表される請求項10~14の何れか一項に記載の非水電解質二次電池。
      (R)(R)N・・・・・・一般式(1)
    (Rは、水素、ハロゲン、置換基で置換されていても良いアルキル基、置換基で置換されていても良いシクロアルキル基、置換基で置換されていても良い不飽和アルキル基、置換基で置換されていても良い不飽和シクロアルキル基、置換基で置換されていても良い芳香族基、置換基で置換されていても良い複素環基、置換基で置換されていても良いアルコキシ基、置換基で置換されていても良い不飽和アルコキシ基、置換基で置換されていても良いチオアルコキシ基、置換基で置換されていても良い不飽和チオアルコキシ基、CN、SCN、OCNから選択される。
     Rは、水素、ハロゲン、置換基で置換されていても良いアルキル基、置換基で置換されていても良いシクロアルキル基、置換基で置換されていても良い不飽和アルキル基、置換基で置換されていても良い不飽和シクロアルキル基、置換基で置換されていても良い芳香族基、置換基で置換されていても良い複素環基、置換基で置換されていても良いアルコキシ基、置換基で置換されていても良い不飽和アルコキシ基、置換基で置換されていても良いチオアルコキシ基、置換基で置換されていても良い不飽和チオアルコキシ基、CN、SCN、OCNからから選択される。
     また、RとRは、互いに結合して環を形成しても良い。
     Xは、SO、C=O、C=S、RP=O、RP=S、S=O、Si=Oから選択される。
     Xは、SO、C=O、C=S、RP=O、RP=S、S=O、Si=Oから選択される。
     R、R、R、Rは、それぞれ独立に、水素、ハロゲン、置換基で置換されていても良いアルキル基、置換基で置換されていても良いシクロアルキル基、置換基で置換されていても良い不飽和アルキル基、置換基で置換されていても良い不飽和シクロアルキル基、置換基で置換されていても良い芳香族基、置換基で置換されていても良い複素環基、置換基で置換されていても良いアルコキシ基、置換基で置換されていても良い不飽和アルコキシ基、置換基で置換されていても良いチオアルコキシ基、置換基で置換されていても良い不飽和チオアルコキシ基、OH、SH、CN、SCN、OCNから選択される。
     また、R、R、R、Rは、RまたはRと結合して環を形成しても良い。)
      RY・・・・・・一般式(2)
    (Rは、水素、ハロゲン、置換基で置換されていても良いアルキル基、置換基で置換されていても良いシクロアルキル基、置換基で置換されていても良い不飽和アルキル基、置換基で置換されていても良い不飽和シクロアルキル基、置換基で置換されていても良い芳香族基、置換基で置換されていても良い複素環基、置換基で置換されていても良いアルコキシ基、置換基で置換されていても良い不飽和アルコキシ基、置換基で置換されていても良いチオアルコキシ基、置換基で置換されていても良い不飽和チオアルコキシ基、CN、SCN、OCNから選択される。
     Xは、SO、C=O、C=S、RP=O、RP=S、S=O、Si=Oから選択される。
     R、Rは、それぞれ独立に、水素、ハロゲン、置換基で置換されていても良いアルキル基、置換基で置換されていても良いシクロアルキル基、置換基で置換されていても良い不飽和アルキル基、置換基で置換されていても良い不飽和シクロアルキル基、置換基で置換されていても良い芳香族基、置換基で置換されていても良い複素環基、置換基で置換されていても良いアルコキシ基、置換基で置換されていても良い不飽和アルコキシ基、置換基で置換されていても良いチオアルコキシ基、置換基で置換されていても良い不飽和チオアルコキシ基、OH、SH、CN、SCN、OCNから選択される。
     また、R、Rは、Rと結合して環を形成しても良い。
     Yは、O、Sから選択される。)
      (R)(R)(R)C・・・・・・一般式(3)
    (Rは、水素、ハロゲン、置換基で置換されていても良いアルキル基、置換基で置換されていても良いシクロアルキル基、置換基で置換されていても良い不飽和アルキル基、置換基で置換されていても良い不飽和シクロアルキル基、置換基で置換されていても良い芳香族基、置換基で置換されていても良い複素環基、置換基で置換されていても良いアルコキシ基、置換基で置換されていても良い不飽和アルコキシ基、置換基で置換されていても良いチオアルコキシ基、置換基で置換されていても良い不飽和チオアルコキシ基、CN、SCN、OCNから選択される。
     Rは、水素、ハロゲン、置換基で置換されていても良いアルキル基、置換基で置換されていても良いシクロアルキル基、置換基で置換されていても良い不飽和アルキル基、置換基で置換されていても良い不飽和シクロアルキル基、置換基で置換されていても良い芳香族基、置換基で置換されていても良い複素環基、置換基で置換されていても良いアルコキシ基、置換基で置換されていても良い不飽和アルコキシ基、置換基で置換されていても良いチオアルコキシ基、置換基で置換されていても良い不飽和チオアルコキシ基、CN、SCN、OCNから選択される。
     Rは、水素、ハロゲン、置換基で置換されていても良いアルキル基、置換基で置換されていても良いシクロアルキル基、置換基で置換されていても良い不飽和アルキル基、置換基で置換されていても良い不飽和シクロアルキル基、置換基で置換されていても良い芳香族基、置換基で置換されていても良い複素環基、置換基で置換されていても良いアルコキシ基、置換基で置換されていても良い不飽和アルコキシ基、置換基で置換されていても良いチオアルコキシ基、置換基で置換されていても良い不飽和チオアルコキシ基、CN、SCN、OCNから選択される。
     また、R、R、Rのうち、いずれか二つまたは三つが結合して環を形成しても良い。
     Xは、SO、C=O、C=S、RP=O、RP=S、S=O、Si=Oから選択される。
     Xは、SO、C=O、C=S、RP=O、RP=S、S=O、Si=Oから選択される。
     Xは、SO、C=O、C=S、RP=O、RP=S、S=O、Si=Oから選択される。
     R、R、R、R、R、Rは、それぞれ独立に、水素、ハロゲン、置換基で置換されていても良いアルキル基、置換基で置換されていても良いシクロアルキル基、置換基で置換されていても良い不飽和アルキル基、置換基で置換されていても良い不飽和シクロアルキル基、置換基で置換されていても良い芳香族基、置換基で置換されていても良い複素環基、置換基で置換されていても良いアルコキシ基、置換基で置換されていても良い不飽和アルコキシ基、置換基で置換されていても良いチオアルコキシ基、置換基で置換されていても良い不飽和チオアルコキシ基、OH、SH、CN、SCN、OCNから選択される。
     また、R、R、R、R、R、Rは、R、RまたはRと結合して環を形成しても良い。)
    The non-aqueous electrolyte according to any one of Claims 10 to 14, wherein the electrolyte has a chemical structure of the anion of the salt represented by the following general formula (1), general formula (2), or general formula (3). Electrolyte secondary battery.
    (R 1 X 1 ) (R 2 X 2 ) N... General formula (1)
    (R 1 is hydrogen, halogen, an alkyl group which may be substituted with a substituent, a cycloalkyl group which may be substituted with a substituent, an unsaturated alkyl group which may be substituted with a substituent, or a substituent. An unsaturated cycloalkyl group which may be substituted with, an aromatic group which may be substituted with a substituent, a heterocyclic group which may be substituted with a substituent, or an alkoxy group which may be substituted with a substituent , An unsaturated alkoxy group that may be substituted with a substituent, a thioalkoxy group that may be substituted with a substituent, an unsaturated thioalkoxy group that may be substituted with a substituent, CN, SCN, or OCN Is done.
    R 2 represents hydrogen, halogen, an alkyl group which may be substituted with a substituent, a cycloalkyl group which may be substituted with a substituent, an unsaturated alkyl group which may be substituted with a substituent, or a substituent. An unsaturated cycloalkyl group which may be substituted, an aromatic group which may be substituted with a substituent, a heterocyclic group which may be substituted with a substituent, an alkoxy group which may be substituted with a substituent, Select from an unsaturated alkoxy group optionally substituted with a substituent, a thioalkoxy group optionally substituted with a substituent, an unsaturated thioalkoxy group optionally substituted with a substituent, CN, SCN, and OCN Is done.
    R 1 and R 2 may be bonded to each other to form a ring.
    X 1 is selected from SO 2 , C = O, C = S, R a P = O, R b P = S, S = O, Si = O.
    X 2 is, SO 2, C = O, C = S, R c P = O, R d P = S, S = O, is selected from Si = O.
    R a , R b , R c , and R d are each independently hydrogen, halogen, an alkyl group that may be substituted with a substituent, a cycloalkyl group that may be substituted with a substituent, or a substituent. An unsaturated alkyl group which may be substituted, an unsaturated cycloalkyl group which may be substituted with a substituent, an aromatic group which may be substituted with a substituent, or a heterocyclic group which may be substituted with a substituent , An alkoxy group that may be substituted with a substituent, an unsaturated alkoxy group that may be substituted with a substituent, a thioalkoxy group that may be substituted with a substituent, and a non-optionally substituted substituent. Selected from saturated thioalkoxy groups, OH, SH, CN, SCN, OCN.
    R a , R b , R c , and R d may combine with R 1 or R 2 to form a ring. )
    R 3 X 3 Y: General formula (2)
    (R 3 is hydrogen, halogen, an alkyl group which may be substituted with a substituent, a cycloalkyl group which may be substituted with a substituent, an unsaturated alkyl group which may be substituted with a substituent, or a substituent. An unsaturated cycloalkyl group which may be substituted with, an aromatic group which may be substituted with a substituent, a heterocyclic group which may be substituted with a substituent, or an alkoxy group which may be substituted with a substituent , An unsaturated alkoxy group that may be substituted with a substituent, a thioalkoxy group that may be substituted with a substituent, an unsaturated thioalkoxy group that may be substituted with a substituent, CN, SCN, or OCN Is done.
    X 3 is selected from SO 2 , C = O, C = S, R e P = O, R f P = S, S = O, and Si = O.
    R e and R f are each independently hydrogen, halogen, an alkyl group that may be substituted with a substituent, a cycloalkyl group that may be substituted with a substituent, or a group that may be substituted with a substituent. A saturated alkyl group, an unsaturated cycloalkyl group that may be substituted with a substituent, an aromatic group that may be substituted with a substituent, a heterocyclic group that may be substituted with a substituent, and a substituent An alkoxy group which may be substituted, an unsaturated alkoxy group which may be substituted with a substituent, a thioalkoxy group which may be substituted with a substituent, an unsaturated thioalkoxy group which may be substituted with a substituent, OH , SH, CN, SCN, and OCN.
    R e and R f may combine with R 3 to form a ring.
    Y is selected from O and S. )
    (R 4 X 4 ) (R 5 X 5 ) (R 6 X 6 ) C ... General formula (3)
    (R 4 is hydrogen, halogen, an alkyl group which may be substituted with a substituent, a cycloalkyl group which may be substituted with a substituent, an unsaturated alkyl group which may be substituted with a substituent, or a substituent. An unsaturated cycloalkyl group which may be substituted with, an aromatic group which may be substituted with a substituent, a heterocyclic group which may be substituted with a substituent, or an alkoxy group which may be substituted with a substituent , An unsaturated alkoxy group that may be substituted with a substituent, a thioalkoxy group that may be substituted with a substituent, an unsaturated thioalkoxy group that may be substituted with a substituent, CN, SCN, or OCN Is done.
    R 5 represents hydrogen, halogen, an alkyl group which may be substituted with a substituent, a cycloalkyl group which may be substituted with a substituent, an unsaturated alkyl group which may be substituted with a substituent, or a substituent. An unsaturated cycloalkyl group which may be substituted, an aromatic group which may be substituted with a substituent, a heterocyclic group which may be substituted with a substituent, an alkoxy group which may be substituted with a substituent, Selected from an unsaturated alkoxy group which may be substituted with a substituent, a thioalkoxy group which may be substituted with a substituent, an unsaturated thioalkoxy group which may be substituted with a substituent, CN, SCN, OCN The
    R 6 is hydrogen, halogen, an alkyl group which may be substituted with a substituent, a cycloalkyl group which may be substituted with a substituent, an unsaturated alkyl group which may be substituted with a substituent, or a substituent. An unsaturated cycloalkyl group which may be substituted, an aromatic group which may be substituted with a substituent, a heterocyclic group which may be substituted with a substituent, an alkoxy group which may be substituted with a substituent, Selected from an unsaturated alkoxy group which may be substituted with a substituent, a thioalkoxy group which may be substituted with a substituent, an unsaturated thioalkoxy group which may be substituted with a substituent, CN, SCN, OCN The
    Further, any two or three of R 4 , R 5 and R 6 may be bonded to form a ring.
    X 4 is, SO 2, C = O, C = S, R g P = O, R h P = S, S = O, is selected from Si = O.
    X 5 is selected from SO 2 , C = O, C = S, R i P = O, R j P = S, S = O, Si = O.
    X 6 is selected from SO 2 , C = O, C = S, R k P = O, R 1 P = S, S = O, Si = O.
    R g , R h , R i , R j , R k , and R l are each independently hydrogen, halogen, an alkyl group that may be substituted with a substituent, or a cycloalkyl that may be substituted with a substituent. Group, an unsaturated alkyl group that may be substituted with a substituent, an unsaturated cycloalkyl group that may be substituted with a substituent, an aromatic group that may be substituted with a substituent, or a substituent that is substituted with a substituent A heterocyclic group which may be substituted, an alkoxy group which may be substituted with a substituent, an unsaturated alkoxy group which may be substituted with a substituent, a thioalkoxy group which may be substituted with a substituent, and a substituent It is selected from an unsaturated thioalkoxy group which may be substituted, OH, SH, CN, SCN, OCN.
    R g , R h , R i , R j , R k , and R l may combine with R 4 , R 5, or R 6 to form a ring. )
  16.  前記電解液は、前記塩のアニオンの化学構造が下記一般式(4)、一般式(5)または一般式(6)で表される請求項10~15の何れか一項に記載の非水電解質二次電池。
      (R)(R)N・・・・・・一般式(4)
    (R、Rは、それぞれ独立に、CClBr(CN)(SCN)(OCN)である。
     n、a、b、c、d、e、f、g、hはそれぞれ独立に0以上の整数であり、2n+1=a+b+c+d+e+f+g+hを満たす。
     また、RとRは、互いに結合して環を形成しても良く、その場合は、2n=a+b+c+d+e+f+g+hを満たす。
     Xは、SO、C=O、C=S、RP=O、RP=S、S=O、Si=Oから選択される。
     Xは、SO、C=O、C=S、RP=O、RP=S、S=O、Si=Oから選択される。
     R、R、R、Rは、それぞれ独立に、水素、ハロゲン、置換基で置換されていても良いアルキル基、置換基で置換されていても良いシクロアルキル基、置換基で置換されていても良い不飽和アルキル基、置換基で置換されていても良い不飽和シクロアルキル基、置換基で置換されていても良い芳香族基、置換基で置換されていても良い複素環基、置換基で置換されていても良いアルコキシ基、置換基で置換されていても良い不飽和アルコキシ基、置換基で置換されていても良いチオアルコキシ基、置換基で置換されていても良い不飽和チオアルコキシ基、OH、SH、CN、SCN、OCNから選択される。
     また、R、R、R、Rは、RまたはRと結合して環を形成しても良い。)
      RY・・・・・・一般式(5)
    (Rは、CClBr(CN)(SCN)(OCN)である。
     n、a、b、c、d、e、f、g、hはそれぞれ独立に0以上の整数であり、2n+1=a+b+c+d+e+f+g+hを満たす。
     Xは、SO、C=O、C=S、RP=O、RP=S、S=O、Si=Oから選択される。
     R、Rは、それぞれ独立に、水素、ハロゲン、置換基で置換されていても良いアルキル基、置換基で置換されていても良いシクロアルキル基、置換基で置換されていても良い不飽和アルキル基、置換基で置換されていても良い不飽和シクロアルキル基、置換基で置換されていても良い芳香族基、置換基で置換されていても良い複素環基、置換基で置換されていても良いアルコキシ基、置換基で置換されていても良い不飽和アルコキシ基、置換基で置換されていても良いチオアルコキシ基、置換基で置換されていても良い不飽和チオアルコキシ基、OH、SH、CN、SCN、OCNから選択される。
     また、R、Rは、Rと結合して環を形成しても良い。
     Yは、O、Sから選択される。)
      (R1010)(R1111)(R1212)C・・・一般式(6)
    (R10、R11、R12は、それぞれ独立に、CClBr(CN)(SCN)(OCN)である。n、a、b、c、d、e、f、g、hはそれぞれ独立に0以上の整数であり、2n+1=a+b+c+d+e+f+g+hを満たす。
     R10、R11、R12のうちいずれか二つが結合して環を形成しても良く、その場合、環を形成する基は2n=a+b+c+d+e+f+g+hを満たす。また、R10、R11、R12の三つが結合して環を形成しても良く、その場合、三つのうち二つの基が2n=a+b+c+d+e+f+g+hを満たし、一つの基が2n-1=a+b+c+d+e+f+g+hを満たす。
     X10は、SO、C=O、C=S、RP=O、RP=S、S=O、Si=Oから選択される。
     X11は、SO、C=O、C=S、RP=O、RP=S、S=O、Si=Oから選択される。
     X12は、SO、C=O、C=S、RP=O、RP=S、S=O、Si=Oから選択される。
     R、R、R、R、R、Rは、それぞれ独立に、水素、ハロゲン、置換基で置換されていても良いアルキル基、置換基で置換されていても良いシクロアルキル基、置換基で置換されていても良い不飽和アルキル基、置換基で置換されていても良い不飽和シクロアルキル基、置換基で置換されていても良い芳香族基、置換基で置換されていても良い複素環基、置換基で置換されていても良いアルコキシ基、置換基で置換されていても良い不飽和アルコキシ基、置換基で置換されていても良いチオアルコキシ基、置換基で置換されていても良い不飽和チオアルコキシ基、OH、SH、CN、SCN、OCNから選択される。
     また、R、R、R、R、R、Rは、R10、R11またはR12と結合して環を形成しても良い。)
    The non-aqueous electrolyte according to any one of claims 10 to 15, wherein the electrolyte has a chemical structure of the anion of the salt represented by the following general formula (4), general formula (5), or general formula (6). Electrolyte secondary battery.
    (R 7 X 7 ) (R 8 X 8 ) N ... General formula (4)
    (R 7 and R 8 are each independently C n H a F b Cl c Br d I e (CN) f (SCN) g (OCN) h .
    n, a, b, c, d, e, f, g, and h are each independently an integer of 0 or more, and satisfy 2n + 1 = a + b + c + d + e + f + g + h.
    R 7 and R 8 may combine with each other to form a ring, in which case 2n = a + b + c + d + e + f + g + h is satisfied.
    X 7 is, SO 2, C = O, C = S, R m P = O, R n P = S, S = O, is selected from Si = O.
    X 8 is selected from SO 2 , C = O, C = S, R o P = O, R p P = S, S = O, Si = O.
    R m , R n , R o , and R p are each independently substituted with hydrogen, halogen, an alkyl group that may be substituted with a substituent, a cycloalkyl group that may be substituted with a substituent, or a substituent. An unsaturated alkyl group which may be substituted, an unsaturated cycloalkyl group which may be substituted with a substituent, an aromatic group which may be substituted with a substituent, or a heterocyclic group which may be substituted with a substituent , An alkoxy group that may be substituted with a substituent, an unsaturated alkoxy group that may be substituted with a substituent, a thioalkoxy group that may be substituted with a substituent, and a non-optionally substituted substituent. Selected from saturated thioalkoxy groups, OH, SH, CN, SCN, OCN.
    R m , R n , R o , and R p may combine with R 7 or R 8 to form a ring. )
    R 9 X 9 Y: General formula (5)
    (R 9 is a C n H a F b Cl c Br d I e (CN) f (SCN) g (OCN) h.
    n, a, b, c, d, e, f, g, and h are each independently an integer of 0 or more, and satisfy 2n + 1 = a + b + c + d + e + f + g + h.
    X 9 is, SO 2, C = O, C = S, R q P = O, R r P = S, S = O, is selected from Si = O.
    R q and R r are each independently hydrogen, halogen, an alkyl group that may be substituted with a substituent, a cycloalkyl group that may be substituted with a substituent, or a group that may be substituted with a substituent. A saturated alkyl group, an unsaturated cycloalkyl group that may be substituted with a substituent, an aromatic group that may be substituted with a substituent, a heterocyclic group that may be substituted with a substituent, and a substituent An alkoxy group which may be substituted, an unsaturated alkoxy group which may be substituted with a substituent, a thioalkoxy group which may be substituted with a substituent, an unsaturated thioalkoxy group which may be substituted with a substituent, OH , SH, CN, SCN, and OCN.
    R q and R r may combine with R 9 to form a ring.
    Y is selected from O and S. )
    (R 10 X 10) (R 11 X 11) (R 12 X 12) C ··· formula (6)
    (R 10 , R 11 , R 12 are each independently C n H a F b Cl c Br d I e (CN) f (SCN) g (OCN) h . N, a, b, c, d, e, f, g, and h are each independently an integer of 0 or more, and satisfy 2n + 1 = a + b + c + d + e + f + g + h.
    Any two of R 10 , R 11 , and R 12 may combine to form a ring, in which case the group forming the ring satisfies 2n = a + b + c + d + e + f + g + h. Three of R 10 , R 11 and R 12 may combine to form a ring, in which case two of the three satisfy 2n = a + b + c + d + e + f + g + h, and one group satisfies 2n−1 = a + b + c + d + e + f + g + h. Fulfill.
    X 10 is, SO 2, C = O, C = S, R s P = O, R t P = S, S = O, is selected from Si = O.
    X 11 is, SO 2, C = O, C = S, R u P = O, R v P = S, S = O, is selected from Si = O.
    X 12 is, SO 2, C = O, C = S, R w P = O, R x P = S, S = O, is selected from Si = O.
    R s , R t , R u , R v , R w , and R x are each independently hydrogen, halogen, an alkyl group that may be substituted with a substituent, or a cycloalkyl that may be substituted with a substituent. Group, an unsaturated alkyl group that may be substituted with a substituent, an unsaturated cycloalkyl group that may be substituted with a substituent, an aromatic group that may be substituted with a substituent, or a substituent that is substituted with a substituent A heterocyclic group which may be substituted, an alkoxy group which may be substituted with a substituent, an unsaturated alkoxy group which may be substituted with a substituent, a thioalkoxy group which may be substituted with a substituent, and a substituent It is selected from an unsaturated thioalkoxy group which may be substituted, OH, SH, CN, SCN, OCN.
    R s , R t , R u , R v , R w , and R x may combine with R 10 , R 11, or R 12 to form a ring. )
  17.  前記塩のカチオンがリチウムである請求項1~16の何れか一項に記載の非水電解質二次電池。 The nonaqueous electrolyte secondary battery according to any one of claims 1 to 16, wherein a cation of the salt is lithium.
  18.  前記塩のアニオンの化学構造が下記一般式(7)、一般式(8)または一般式(9)で表される請求項1~17の何れか一項に記載の非水電解質二次電池。
      (R13SO)(R14SO)N・・・・・・一般式(7)
    (R13、R14は、それぞれ独立に、CClBrである。
     n、a、b、c、d、eはそれぞれ独立に0以上の整数であり、2n+1=a+b+c+d+eを満たす。
     また、R13とR14は、互いに結合して環を形成しても良く、その場合は、2n=a+b+c+d+eを満たす。)
      R15SO・・・・・・一般式(8)
    (R15は、CClBrである。
     n、a、b、c、d、eはそれぞれ独立に0以上の整数であり、2n+1=a+b+c+d+eを満たす。)
     (R16SO)(R17SO)(R18SO)C・・一般式(9)
    (R16、R17、R18は、それぞれ独立に、CClBrである。
     n、a、b、c、d、eはそれぞれ独立に0以上の整数であり、2n+1=a+b+c+d+eを満たす。
     R16、R17、R18のうちいずれか2つが結合して環を形成しても良く、その場合、環を形成する基は2n=a+b+c+d+eを満たす。また、R16、R17、R18の3つが結合して環を形成しても良く、その場合、3つのうち2つの基が2n=a+b+c+d+eを満たし、1つの基が2n-1=a+b+c+d+eを満たす。)
    The nonaqueous electrolyte secondary battery according to any one of claims 1 to 17, wherein a chemical structure of the anion of the salt is represented by the following general formula (7), general formula (8), or general formula (9).
    (R 13 SO 2 ) (R 14 SO 2 ) N... General formula (7)
    (R 13 and R 14 are each independently C n H a F b Cl c Br d I e .
    n, a, b, c, d, and e are each independently an integer of 0 or more, and satisfy 2n + 1 = a + b + c + d + e.
    R 13 and R 14 may combine with each other to form a ring, in which case 2n = a + b + c + d + e is satisfied. )
    R 15 SO 3 ... General formula (8)
    (R 15 is a C n H a F b Cl c Br d I e.
    n, a, b, c, d, and e are each independently an integer of 0 or more, and satisfy 2n + 1 = a + b + c + d + e. )
    (R 16 SO 2 ) (R 17 SO 2 ) (R 18 SO 2 ) C. General formula (9)
    (R 16 , R 17 , and R 18 are each independently C n H a F b Cl c Br d I e .
    n, a, b, c, d, and e are each independently an integer of 0 or more, and satisfy 2n + 1 = a + b + c + d + e.
    Any two of R 16 , R 17 , and R 18 may combine to form a ring, in which case the group forming the ring satisfies 2n = a + b + c + d + e. Three of R 16 , R 17 and R 18 may combine to form a ring, in which case two groups out of the three satisfy 2n = a + b + c + d + e, and one group satisfies 2n−1 = a + b + c + d + e. Fulfill. )
  19.  前記塩が(CFSONLi、(FSONLi、(CSONLi、FSO(CFSO)NLi、(SOCFCFSO)NLi、または(SOCFCFCFSO)NLiである請求項1~18の何れか一項に記載の非水電解質二次電池。 The salt is (CF 3 SO 2 ) 2 NLi, (FSO 2 ) 2 NLi, (C 2 F 5 SO 2 ) 2 NLi, FSO 2 (CF 3 SO 2 ) NLi, (SO 2 CF 2 CF 2 SO 2 ) The nonaqueous electrolyte secondary battery according to any one of claims 1 to 18, which is NLi or (SO 2 CF 2 CF 2 CF 2 SO 2 ) NLi.
  20.  前記有機溶媒のヘテロ元素が窒素、酸素、硫黄、ハロゲンから選択される少なくとも1つである請求項1~19の何れか一項に記載の非水電解質二次電池。 The nonaqueous electrolyte secondary battery according to any one of claims 1 to 19, wherein the hetero element of the organic solvent is at least one selected from nitrogen, oxygen, sulfur, and halogen.
  21.  前記有機溶媒が非プロトン性溶媒である請求項1~20の何れか一項に記載の非水電解質二次電池。 The non-aqueous electrolyte secondary battery according to any one of claims 1 to 20, wherein the organic solvent is an aprotic solvent.
  22.  前記有機溶媒がアセニトリルまたは1,2-ジメトキシエタンから選択される請求項1~21の何れか一項に記載の非水電解質二次電池。 The nonaqueous electrolyte secondary battery according to any one of claims 1 to 21, wherein the organic solvent is selected from acetonitrile or 1,2-dimethoxyethane.
  23.  前記有機溶媒が下記一般式(10)で示される鎖状カーボネートから選択される請求項1~22の何れか一項に記載の非水電解質二次電池。
      R19OCOOR20・・・・・・一般式(10)
    (R19、R20は、それぞれ独立に、鎖状アルキルであるCClBr、または、環状アルキルを化学構造に含むCClBrのいずれかから選択される。n、a、b、c、d、e、m、f、g、h、i、jはそれぞれ独立に0以上の整数であり、2n+1=a+b+c+d+e、2m=f+g+h+i+jを満たす。)
    The nonaqueous electrolyte secondary battery according to any one of claims 1 to 22, wherein the organic solvent is selected from chain carbonates represented by the following general formula (10).
    R 19 OCOOR 20 ··· General formula (10)
    (R 19 and R 20 are each independently C n H a F b Cl c Br d I e which is a chain alkyl, or C m H f F g Cl h Br i I containing a cyclic alkyl in the chemical structure. .n selected from any of j, a, b, c, d, e, m, f, g, h, i, j are each independently an integer of 0 or more, 2n + 1 = a + b + c + d + e, 2m = f + g + h + i + j Meet)
  24.  前記有機溶媒がジメチルカーボネート、エチルメチルカーボネートまたはジエチルカーボネートから選択される請求項1~21、請求項23の何れか一項に記載の非水電解質二次電池。 The nonaqueous electrolyte secondary battery according to any one of claims 1 to 21, and 23, wherein the organic solvent is selected from dimethyl carbonate, ethyl methyl carbonate, and diethyl carbonate.
PCT/JP2014/004917 2013-09-25 2014-09-25 Nonaqueous electrolyte secondary battery WO2015045393A1 (en)

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KR1020167010618A KR101901676B1 (en) 2013-09-25 2014-09-25 Nonaqueous electrolyte secondary battery
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