WO2015045393A1 - Batterie secondaire à électrolyte non aqueux - Google Patents

Batterie secondaire à électrolyte non aqueux 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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English (en)
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/ja
Priority claimed from JP2014186352A external-priority patent/JP5967781B2/ja
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 KR1020167010618A priority Critical patent/KR101901676B1/ko
Priority to DE112014004443.1T priority patent/DE112014004443T5/de
Priority to US15/024,654 priority patent/US20160240858A1/en
Priority to CN201480053188.4A priority patent/CN105580192B/zh
Publication of WO2015045393A1 publication Critical patent/WO2015045393A1/fr
Priority to US15/993,729 priority patent/US20180277852A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
    • H01M10/0564—Accumulators 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
    • H01M10/0566—Liquid materials
    • H01M10/0568—Liquid materials characterised by the solutes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/621—Binders
    • H01M4/622—Binders being polymers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
    • H01M10/0564—Accumulators 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
    • H01M10/0566—Liquid materials
    • H01M10/0567—Liquid materials characterised by the additives
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
    • H01M10/0564—Accumulators 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
    • H01M10/0566—Liquid materials
    • H01M10/0569—Liquid materials characterised by the solvents
    • Y—GENERAL 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
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy 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.

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Abstract

Batterie secondaire à électrolyte non aqueux qui a d'excellentes caractéristiques de batterie, tout en ayant un film de revêtement SEI à structure spéciale. Selon l'invention, une solution d'électrolyte contient un solvant organique ayant un hétéroélément et un sel; un métal alcalin, un métal alcalino-terreux ou de l'aluminium étant utilisé sous forme de cations. La solution d'électrolyte est telle qu'elle satisfait la relation Is > Io, et qu'elle est utilisée sous la forme de la solution d'électrolyte de la batterie secondaire à électrolyte non aqueux de la présente invention. Un film de revêtement contenant S et O, et ayant une structure S = O est formé sur la surface de l'électrode positive et/ou sur la surface de l'électrode négative. En variante, la solution d'électrolyte décrite ci-dessus est utilisée dans la batterie secondaire à électrolyte non aqueux de la présente invention, et un liant constitué d'un polymère ayant un groupe hydrophile est utilisé en tant que liant pour l'électrode négative.
PCT/JP2014/004917 2013-09-25 2014-09-25 Batterie secondaire à électrolyte non aqueux WO2015045393A1 (fr)

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KR1020167010618A KR101901676B1 (ko) 2013-09-25 2014-09-25 비수 전해질 2차 전지
DE112014004443.1T DE112014004443T5 (de) 2013-09-25 2014-09-25 Nichtwässrige Elektrolytsekundärbatterie
US15/024,654 US20160240858A1 (en) 2013-09-25 2014-09-25 Nonaqueous electrolyte secondary battery
CN201480053188.4A CN105580192B (zh) 2013-09-25 2014-09-25 非水电解质二次电池
US15/993,729 US20180277852A1 (en) 2013-09-25 2018-05-31 Nonaqueous electrolyte secondary battery

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JP2013198281 2013-09-25
JP2013-198286 2013-09-25
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JP2013198286 2013-09-25
JP2014-065804 2014-03-27
JP2014065804 2014-03-27
JP2014-106727 2014-05-23
JP2014106727 2014-05-23
JP2014-186351 2014-09-12
JP2014-186352 2014-09-12
JP2014186351A JP5965444B2 (ja) 2013-09-25 2014-09-12 非水系二次電池
JP2014186352A JP5967781B2 (ja) 2013-09-25 2014-09-12 非水電解質二次電池

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US15/993,729 Division US20180277852A1 (en) 2013-09-25 2018-05-31 Nonaqueous electrolyte secondary battery

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CN111313086A (zh) * 2019-12-24 2020-06-19 安徽圣格能源科技有限公司 一种电解液及锂离子电池

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