WO2019093159A1 - Electrolyte solution, electrochemical device, lithium ion secondary battery, and module - Google Patents

Electrolyte solution, electrochemical device, lithium ion secondary battery, and module Download PDF

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WO2019093159A1
WO2019093159A1 PCT/JP2018/039903 JP2018039903W WO2019093159A1 WO 2019093159 A1 WO2019093159 A1 WO 2019093159A1 JP 2018039903 W JP2018039903 W JP 2018039903W WO 2019093159 A1 WO2019093159 A1 WO 2019093159A1
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group
carbonate
anhydride
methyl
mass
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PCT/JP2018/039903
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French (fr)
Japanese (ja)
Inventor
佳子 桑嶋
航太郎 林
尚子 仲村
知哉 日高
貴哉 山田
悠希 鈴木
穣輝 山崎
昭佳 山内
謙三 高橋
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ダイキン工業株式会社
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Publication of WO2019093159A1 publication Critical patent/WO2019093159A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
    • H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
    • H01G11/54—Electrolytes
    • H01G11/58—Liquid electrolytes
    • H01G11/64—Liquid electrolytes characterised by 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
    • H01M10/052—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
    • H01M10/0567—Liquid materials characterised by the additives
    • 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 an electrolytic solution, an electrochemical device, a lithium ion secondary battery and a module.
  • Patent Document 1 in the electrolytic solution obtained by dissolving a lithium salt in a solvent mainly composed of at least one non-aqueous solvent selected from the group consisting of carbonate ester, ether and lactone, the solvent is a dicarboxylic acid diester (wherein An electrolytic solution is described which is characterized in that it contains a succinic acid diester) or a derivative thereof and an aromatic compound having a molecular weight of 500 or less.
  • the non-aqueous electrolyte contains vinylene carbonate and di (2-propynyl) oxalate, and the addition amount of the vinylene carbonate is 0.1% by mass or more and 3% by mass with respect to the mass of the non-aqueous electrolyte. % Or less, and the addition amount of the di (2-propynyl) oxalate is 0.1% by mass or more and 2% by mass or less with respect to the mass of the non-aqueous electrolyte, and the non-aqueous electrolyte contains ethylene carbonate and non-ethylene carbonate.
  • a non-aqueous electrolyte secondary battery is described which is composed of a mixed solvent with a cyclic carbonate, and the content of the ethylene carbonate is 20% by volume or more and 40% by volume or less of the mixed solvent.
  • Patent Document 3 describes a secondary battery that includes an electrolytic solution together with a positive electrode and a negative electrode, and the electrolytic solution contains a combination of a non-aqueous solvent, an electrolyte salt, and a specific compound.
  • Patent Document 4 is an electrolytic solution containing a solvent and an electrolyte salt, and the solvent contains 0.001 to 10 ppm of the compound (A) represented by the general formula (A) in the electrolytic solution.
  • An electrolytic solution is described.
  • R 1 and R 2 may be the same or different, and are an alkyl group having 1 to 7 carbon atoms.
  • the present invention was made in view of the above-mentioned present situation, and it is an object of the present invention to provide an electrolytic solution capable of improving high temperature storage characteristics and cycle characteristics of an electrochemical device, and an electrochemical device provided with the electrolytic solution. I assume.
  • the inventors of the present invention have found that the above-mentioned problems can be satisfactorily solved when two or more kinds of oxalic acid ester compounds having a specific structure are contained, and the present invention has been accomplished.
  • the present invention relates to a compound (1) represented by the following general formula (1), a compound (11) represented by the following general formula (11), and a compound (12) represented by the following general formula (12) And at least one selected from the group consisting of General formula (1): (Wherein, R 101 is an alkyl group having 1 to 4 carbon atoms, and R 102 is an alkenyl group having 2 to 4 carbon atoms.)
  • General formula (11) (Wherein, R 101 is the same as above).
  • the present invention is also an electrochemical device comprising the above-mentioned electrolytic solution.
  • the present invention is also a lithium ion secondary battery comprising the above-mentioned electrolytic solution.
  • the present invention is also a module including the electrochemical device or the lithium ion secondary battery.
  • electrolytic solution of the present invention high temperature storage characteristics and cycle characteristics of the electrochemical device can be improved.
  • the electrochemical device provided with the above-mentioned electrolytic solution is excellent in high-temperature storage characteristics and cycle characteristics.
  • the electrolytic solution of the present invention has the following general formula (1): And a compound (1) represented by the following general formula (11): The compound (11) represented by and the following general formula (12): And at least one selected from the group consisting of compounds (12) Due to this feature, the electrolytic solution of the present invention can improve the high temperature storage characteristics and cycle characteristics of the electrochemical device.
  • R 101 is an alkyl group having 1 to 4 carbon atoms.
  • the carbon number of R 101 is preferably 1 to 3, and more preferably 1 to 2.
  • R 101 a methyl group (—CH 3 ) and an ethyl group (—CH 2 CH 3 ) are preferable. It is preferable that the said alkyl group does not have a fluorine atom, and it is more preferable that it does not have a halogen atom.
  • R 102 is an alkenyl group having 2 to 4 carbon atoms.
  • two R 101 are preferably the same, and in the general formula (12), the two R 102 are preferably the same.
  • Specific examples of the compound (1) include compounds represented by the following formulae.
  • the compounds (1), (11) and (12) may be used alone or in combination of two or more.
  • the electrolytic solution of the present invention preferably contains 0.001 to 20% by mass of the compound (1) with respect to the electrolytic solution.
  • content of the compound (1) is in the above range, the high temperature storage characteristics and the cycle characteristics of the electrochemical device can be further improved.
  • content of a compound (1) 0.005 mass% or more is more preferable, 0.01 mass% or more is further more preferable, 0.1 mass% or more is still more preferable, 0.5 mass% or more is especially preferable .
  • 15 mass% or less is more preferable, 10 mass% or less is more preferable, 7.0 mass% or less is still more preferable, 5.0 mass% or less is especially preferable.
  • the content of the compound (11) is preferably 0.001 to 1500 mass ppm with respect to the electrolytic solution.
  • the content of the compound (11) is in the above range, the high temperature storage characteristics and the cycle characteristics of the electrochemical device can be further improved.
  • content of a compound (11) 0.005 mass ppm or more is more preferable, 0.01 mass ppm or more is still more preferable, 1.0 mass ppm or more is especially preferable.
  • 1000 mass ppm or less is more preferable, 500 mass ppm or less is still more preferable, and 100 mass ppm or less is especially preferable.
  • the content of the compound (12) is preferably 0.001 to 1500 mass ppm with respect to the electrolytic solution.
  • the content of the compound (12) is in the above range, the high temperature storage characteristics and cycle characteristics of the electrochemical device can be further improved.
  • content of a compound (12) 0.002 mass ppm or more is more preferable, 0.01 mass ppm or more is still more preferable, 1.0 mass ppm or more is still more preferable.
  • 1000 mass ppm or less is more preferable, 500 mass ppm or less is still more preferable, and 100 mass ppm or less is especially preferable.
  • the electrolytic solution of the present invention preferably contains both the compounds (11) and (12).
  • the electrolytic solution of the present invention is further characterized by the following general formula (13): (Wherein, R 101 is an alkyl group having 1 to 4 carbon atoms, and R 102 is an alkenyl group having 2 to 4 carbon atoms.)
  • the compound (13) may be included.
  • the electrolytic solution contains the compound (13), high temperature storage characteristics and cycle characteristics of the electrochemical device can be further improved.
  • R 101 and R 102 are as described above.
  • one type may be used alone, or two or more types may be used in combination.
  • the content of the compound (13) is preferably 0.001 to 100 mass ppm with respect to the electrolytic solution.
  • the content of the compound (13) is in the above range, the high temperature storage characteristics and the cycle characteristics of the electrochemical device can be further improved.
  • content of a compound (13) 0.01 mass ppm or more is more preferable, 0.1 mass ppm or more is still more preferable, 0.5 mass ppm or more is especially preferable.
  • 50 mass ppm or less is more preferable, 30 mass ppm or less is still more preferable, and 10 mass ppm or less is still more preferable.
  • the electrolytic solution of the present invention preferably contains a solvent (excluding compounds (1) and (11) to (13)).
  • the solvent preferably contains at least one selected from the group consisting of carbonate and carboxylic acid ester.
  • the carbonate may be a cyclic carbonate or a linear carbonate.
  • the cyclic carbonate may be a non-fluorinated cyclic carbonate or a fluorinated cyclic carbonate.
  • non-fluorinated cyclic carbonates examples include non-fluorinated saturated cyclic carbonates.
  • Non-fluorinated saturated alkylene carbonates having an alkylene group of 2 to 6 carbon atoms are preferable, and non-fluorinated compounds having an alkylene group of 2 to 4 carbon atoms Saturated alkylene carbonate is more preferred.
  • ethylene carbonate, propylene carbonate, cis-2,3-pentylene carbonate, cis-2,3-butylene carbonate are preferred as the above non-fluorinated saturated cyclic carbonate in that the dielectric constant is high and the viscosity is suitable.
  • Preferred is at least one selected from the group consisting of 2,3-pentylene carbonate, 2,3-butylene carbonate, 1,2-pentylene carbonate, 1,2-butylene carbonate and butylene carbonate.
  • the said non-fluorinated saturated cyclic carbonate may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.
  • the content of the non-fluorinated saturated cyclic carbonate is preferably 5 to 90% by volume, more preferably 10 to 60% by volume, with respect to the solvent. Preferably, it is 15 to 45% by volume.
  • the fluorinated cyclic carbonate is a cyclic carbonate having a fluorine atom.
  • the solvent containing fluorinated cyclic carbonate can be suitably used even under high voltage.
  • “high voltage” refers to a voltage of 4.2 V or more.
  • 4.9 V is preferable.
  • the fluorinated cyclic carbonate may be a fluorinated saturated cyclic carbonate or a fluorinated unsaturated cyclic carbonate.
  • the fluorinated saturated cyclic carbonate is a saturated cyclic carbonate having a fluorine atom, and specifically, the following general formula (A):
  • X 1 to X 4 are the same or different and each is —H, —CH 3 , —C 2 H 5 , —F, a fluorinated alkyl group which may have an ether bond, or an ether bond
  • a compound represented by the above formula is a good fluorinated alkoxy group.
  • the fluorinated alkyl group is —CF 3 , —CF 2 H, —CH 2 F or the like.
  • ether bond is a bond represented by —O—.
  • one or two of X 1 to X 4 may have -F, a fluorinated alkyl group which may have an ether bond, or an ether bond It is preferable that it is a fluorinated alkoxy group.
  • X 1 to X 4 are —H, ⁇ F, a fluorinated alkyl group (a), an ether bond, because a decrease in viscosity at low temperatures, an increase in flash point, and an increase in solubility of electrolyte salts can be expected. It is preferable that it is a fluorinated alkyl group (b) or a fluorinated alkoxy group (c).
  • the said fluorinated alkyl group (a) is what substituted at least 1 of the hydrogen atom which an alkyl group has with a fluorine atom.
  • the carbon number of the fluorinated alkyl group (a) is preferably 1 to 20, more preferably 1 to 17, still more preferably 1 to 7, and particularly preferably 1 to 5. If the number of carbons is too large, the low temperature characteristics may deteriorate or the solubility of the electrolyte salt may decrease. If the number of carbons is too small, the solubility of the electrolyte salt may decrease, the discharge efficiency may decrease, and further An increase in viscosity etc. may be observed.
  • one having 1 carbon atom includes CFH 2- , CF 2 H-and CF 3- .
  • CF 2 H— or CF 3 — is preferable in view of high-temperature storage characteristics, and CF 3 — is most preferable.
  • those having 2 or more carbon atoms include those represented by the following general formula (a-1): R 1 -R 2- (a-1) (Wherein, R 1 is an alkyl group having 1 or more carbon atoms which may have a fluorine atom; R 2 is an alkylene group having 1 to 3 carbon atoms which may have a fluorine atom; however, R 1 and The fluorinated alkyl group represented by at least one of R 2 s having a fluorine atom can be preferably exemplified from the viewpoint of good solubility of the electrolyte salt. R 1 and R 2 may further have other atoms than carbon atoms, hydrogen atoms and fluorine atoms.
  • R 1 is an alkyl group having one or more carbon atoms which may have a fluorine atom.
  • R 1 a linear or branched alkyl group having 1 to 16 carbon atoms is preferable.
  • the number of carbon atoms of R 1 is more preferably 1 to 6, and still more preferably 1 to 3.
  • R 1 specifically, as a linear or branched alkyl group, CH 3- , CH 3 CH 2- , CH 3 CH 2 CH 2- , CH 3 CH 2 CH 2 CH 2- ,
  • R 1 is a linear alkyl group having a fluorine atom, CF 3- , CF 3 CH 2- , CF 3 CF 2- , CF 3 CH 2 CH 2- , CF 3 CF 2 CH 2- , CF 3 CF 2 CF 2 - , CF 3 CH 2 CF 2 -, CF 3 CH 2 CH 2 CH 2 -, CF 3 CF 2 CH 2 CH 2 -, CF 3 CH 2 CF 2 CH 2 -, CF 3 CH 2 CF 2 CH 2 -, CF 3 CF 2 CF 2 CH 2- , CF 3 CF 2 CF 2 CF 2- , CF 3 CF 2 CH 2 CF 2- , CF 3 CH 2 CH 2 CH 2- , CF 3 CH 2 CF 2 CH 2 CH 2- , CF 3 CH 2 CF 2 CH 2 CH 2- , CF 3 CH 2 CF 2 CH 2 CH 2- , CF 3 CH 2 CF 2 CH 2 CH 2- , CF 3 CH 2 CF 2 CH 2 CH 2- ,
  • R 1 is a branched alkyl group having a fluorine atom
  • Etc. are preferably mentioned. However, since the viscosity is likely to be high when having a branch such as CH 3 -or CF 3- , it is more preferable that the number thereof is small (one) or zero.
  • R 2 is an alkylene group having 1 to 3 carbon atoms which may have a fluorine atom.
  • R 2 may be linear or branched.
  • An example of the minimum structural unit which comprises such a linear or branched alkylene group is shown below.
  • R 2 is composed of these alone or in combination.
  • R 2 is linear, it consists only of the above-mentioned linear minimum structural unit, and in particular, —CH 2 —, —CH 2 CH 2 — or —CF 2 — is preferable.
  • -CH 2 -or -CH 2 CH 2 - is more preferable because the solubility of the electrolyte salt can be further improved.
  • R 2 When R 2 is branched, it contains at least one of the branched minimum structural units described above, and has a general formula of-(CX a X b )-(X a is H, F , CH 3 or CF 3;.
  • X b is CH 3 or CF 3 provided that when X b is CF 3, X a is one represented by H or CH 3) it can be preferably exemplified. In particular, these can further improve the solubility of the electrolyte salt.
  • Preferred fluorinated alkyl group (a) for example CF 3 CF 2 -, HCF 2 CF 2 -, H 2 CFCF 2 -, CH 3 CF 2 -, CF 3 CHF-, CH 3 CF 2 -, CF 3 CF 2 CF 2- , HCF 2 CF 2 CF 2- , H 2 CFCF 2 CF 2- , CH 3 CF 2 CF 2- ,
  • the fluorinated alkyl group (b) having an ether bond is one in which at least one of the hydrogen atoms of the alkyl group having an ether bond is substituted with a fluorine atom.
  • the fluorinated alkyl group (b) having an ether bond preferably has 2 to 17 carbon atoms. If the number of carbon atoms is too large, the viscosity of the fluorinated saturated cyclic carbonate becomes high, and the number of fluorine-containing groups increases. Therefore, the solubility of the electrolyte salt is reduced due to the reduction of the dielectric constant, and the compatibility with other solvents May be seen. From this viewpoint, the carbon number of the fluorinated alkyl group (b) having an ether bond is more preferably 2 to 10, still more preferably 2 to 7.
  • the alkylene group constituting the ether portion of the fluorinated alkyl group (b) having an ether bond may be a linear or branched alkylene group. Examples of the minimum structural unit constituting such a linear or branched alkylene group are shown below.
  • the alkylene group may be composed of these minimum structural units alone, and linear (i), branched (ii) or linear (i) and branched (ii) It may be configured by a combination. Preferred specific examples will be described later.
  • fluorinated alkyl group (b) having an ether bond include general formula (b-1): R 3- (OR 4 ) n 1-(b-1) (Wherein, R 3 may have a fluorine atom, preferably an alkyl group having 1 to 6 carbon atoms; R 4 may have a fluorine atom, preferably an alkylene having 1 to 4 carbon atoms And n1 is an integer of 1 to 3, provided that at least one of R 3 and R 4 has a fluorine atom.
  • R 3 and R 4 include the following, which can be combined as appropriate to form a fluorinated alkyl group (b) having an ether bond represented by the above general formula (b-1). Not limited to these.
  • R 3 a general formula: X c 3 C- (R 5 ) n 2- (wherein three X c are the same or different, each is H or F; R 5 is a C 1-5 fluorine atom Alkylene group which may be possessed; n2 is preferably an alkyl group represented by 0 or 1).
  • R 3 includes CH 3- , CF 3- , HCF 2 -and H 2 CF-.
  • n2 is 1, as R 3 is linear, CF 3 CH 2- , CF 3 CF 2- , CF 3 CH 2 CH 2- , CF 3 CF 2 CH 2- , CF 3 CF 2 CF 2 -, CF 3 CH 2 CF 2 -, CF 3 CH 2 CH 2 CH 2 -, CF 3 CH 2 CF 2 CH 2 -, CF 3 CH 2 CF 2 CH 2 -, CF 3 CF 2 CF 2 CH 2- , CF 3 CF 2 CF 2 CF 2- , CF 3 CF 2 CH 2 CF 2- , CF 3 CH 2 CH 2 CH 2- , CF 3 CH 2 CF 2 CH 2 CH 2- , CF 3 CH 2 CF 2 CH 2 CH 2- , CF 3 CH 2 CF 2 CH 2 CH 2 -, CF 3 CF 2 CF 2 CH 2 CH 2 -, CF 3 CF 2 CF 2 CH 2 CH 2 -, CF 3 CF 2 CH 2 CH 2 -, CF 3 CF 2 CH 2 CH
  • n2 is 1 and R 3 is a branched chain
  • R 3 is linear.
  • n1 is an integer of 1 to 3, preferably 1 or 2.
  • R 4 may be the same or different.
  • R 4 As preferable specific examples of R 4 , the following linear or branched ones can be exemplified.
  • the said fluorinated alkoxy group (c) substitutes at least one of the hydrogen atoms which an alkoxy group has with a fluorine atom.
  • the fluorinated alkoxy group (c) preferably has 1 to 17 carbon atoms. More preferably, it has 1 to 6 carbon atoms.
  • the fluorinated alkoxy group (c) may be represented by the general formula: X d 3 C- (R 6 ) n 3 -O- (wherein three X d are the same or different and each is H or F; R 6 preferably has carbon atoms Particularly preferred is a fluorinated alkoxy group represented by an alkylene group which may have 1 to 5 fluorine atoms; n3 is 0 or 1; provided that any of three X d 's contains a fluorine atom.
  • fluorinated alkoxy group (c) examples include a fluorinated alkoxy group in which an oxygen atom is bonded to the end of the alkyl group exemplified as R 1 in the general formula (a-1).
  • the fluorine content of the fluorinated alkyl group (a) in the fluorinated saturated cyclic carbonate, the fluorinated alkyl group (b) having an ether bond, and the fluorinated alkoxy group (c) is preferably 10% by mass or more. If the fluorine content is too low, the viscosity lowering effect at low temperatures and the flash point raising effect may not be sufficiently obtained. From this viewpoint, the fluorine content is more preferably 12% by mass or more, and still more preferably 15% by mass or more. The upper limit is usually 76% by mass.
  • the fluorine content of the fluorinated alkyl group (a), the fluorinated alkyl group (b) having an ether bond, and the fluorinated alkoxy group (c) is ⁇ (number of fluorine atoms based on the structural formula of each group It is the value computed by x19) / formula weight of each group ⁇ x 100 (%).
  • the fluorine content of the entire fluorinated saturated cyclic carbonate is preferably 10% by mass or more, and more preferably 15% by mass or more.
  • the upper limit is usually 76% by mass.
  • the fluorine content of the fluorinated saturated cyclic carbonate is determined by ⁇ (number of fluorine atoms ⁇ 19) / molecular weight of fluorinated saturated cyclic carbonate ⁇ ⁇ 100 (%) based on the structural formula of fluorinated saturated cyclic carbonate It is a calculated value.
  • fluorinated saturated cyclic carbonate examples include the following.
  • Etc. can also be used.
  • fluorinated saturated cyclic carbonate in which at least one of X 1 to X 4 is a fluorinated alkyl group (a) and the rest are all —H are as follows:
  • fluorinated saturated cyclic carbonate in which at least one of X 1 to X 4 is a fluorinated alkyl group (b) having an ether bond or a fluorinated alkoxy group (c) and the rest is all -H.
  • the fluorinated saturated cyclic carbonate is preferably any of the following compounds.
  • trans-4,5-difluoro-1,3-dioxolan-2-one 5- (1,1-difluoroethyl) -4,4-difluoro-1, 3-dioxolan-2-one
  • 4-methylene-1,3-dioxolan-2-one 4-methyl-5-trifluoromethyl-1,3-dioxolan-2-one
  • 4-ethyl-5,5-difluoro-1,3-dioxolan-2-one 4-ethyl-4,5-difluoro-1,3-dioxolan-2-one
  • 4-ethyl-4,5,5-trifluoro-1,3-dioxolan-2-one 4-ethyl-4,5,5-trifluoro-1,3-dioxolan-2-one, 4,4-difluoro-5-methyl-1,3-diox
  • fluoroethylene carbonate fluoroethylene carbonate, difluoroethylene carbonate, trifluoromethylethylene carbonate (3,3,3-trifluoropropylene carbonate), 2,2,3,3,3-pentafluoro, among others Propyl ethylene carbonate is more preferred.
  • the fluorinated unsaturated cyclic carbonate is a cyclic carbonate having an unsaturated bond and a fluorine atom, and is preferably a fluorinated ethylene carbonate derivative substituted with a substituent having an aromatic ring or a carbon-carbon double bond.
  • the fluorinated cyclic carbonates may be used alone or in any combination of two or more in any proportion.
  • the content of the fluorinated cyclic carbonate is preferably 5 to 90% by volume, more preferably 10 to 60% by volume, with respect to the solvent, and 15 to 50% by volume. More preferably, it is 45% by volume.
  • the linear carbonate may be a non-fluorinated linear carbonate or a fluorinated linear carbonate.
  • non-fluorinated linear carbonates examples include CH 3 OCOOCH 3 (dimethyl carbonate: DMC), CH 3 CH 2 OCOOCH 2 CH 3 (diethyl carbonate: DEC), CH 3 CH 2 OCOOCH 3 (ethyl methyl carbonate: EMC) ), CH 3 OCOOCH 2 CH 2 CH 3 (methyl propyl carbonate), methyl butyl carbonate, ethyl propyl carbonate, ethyl butyl carbonate, dipropyl carbonate, dibutyl carbonate, methyl isopropyl carbonate, methyl 2-phenylphenyl carbonate, phenyl-2 -Phenylphenyl carbonate, trans-2,3-pentylene carbonate, trans-2,3-butylene carbonate, ethyl phenyl carbonate It includes hydrocarbon chain carbonate. Among them, at least one selected from the group consisting of ethyl methyl carbonate, diethyl carbonate and dimethyl carbonate
  • the above non-fluorinated linear carbonates may be used alone or in any combination of two or more in any proportion.
  • the content of the non-fluorinated linear carbonate is preferably 10 to 90% by volume, more preferably 40 to 85% by volume with respect to the solvent. Preferably, it is 50 to 80% by volume.
  • the fluorinated linear carbonate is a linear carbonate having a fluorine atom.
  • the solvent containing fluorinated linear carbonate can be suitably used even under high voltage.
  • Rf 2 OCOOR 7 (B) (Wherein, R f 2 is a fluorinated alkyl group having 1 to 7 carbon atoms, and R 7 is an alkyl group having 1 to 7 carbon atoms which may contain a fluorine atom) It can be mentioned.
  • Rf 2 is a fluorinated alkyl group having 1 to 7 carbon atoms
  • R 7 is an alkyl group which may contain a fluorine atom having 1 to 7 carbon atoms.
  • the said fluorinated alkyl group substitutes at least one of the hydrogen atoms which an alkyl group has with a fluorine atom.
  • R 7 is an alkyl group containing a fluorine atom, it is a fluorinated alkyl group.
  • Rf 2 and R 7 preferably have 1 to 7 carbon atoms, and more preferably 1 to 2 carbon atoms. If the number of carbons is too large, the low temperature characteristics may deteriorate or the solubility of the electrolyte salt may decrease. If the number of carbons is too small, the solubility of the electrolyte salt may decrease, the discharge efficiency may decrease, and further An increase in viscosity etc. may be observed.
  • fluorinated alkyl group having 1 carbon atom examples include CFH 2- , CF 2 H-, and CF 3- .
  • CFH 2 -or CF 3 - is preferable in view of high temperature storage characteristics.
  • Examples of the fluorinated alkyl group having 2 or more carbon atoms include the following general formula (d-1): R 1 -R 2- (d-1) (Wherein, R 1 is an alkyl group having 1 or more carbon atoms which may have a fluorine atom; R 2 is an alkylene group having 1 to 3 carbon atoms which may have a fluorine atom; however, R 1 and The fluorinated alkyl group represented by at least one of R 2 s having a fluorine atom can be preferably exemplified from the viewpoint of good solubility of the electrolyte salt. R 1 and R 2 may further have other atoms than carbon atoms, hydrogen atoms and fluorine atoms.
  • R 1 is an alkyl group having one or more carbon atoms which may have a fluorine atom.
  • R 1 a linear or branched alkyl group having 1 to 6 carbon atoms is preferable.
  • the number of carbon atoms of R 1 is more preferably 1 to 3.
  • R 1 specifically, as a linear or branched alkyl group, CH 3- , CF 3- , CH 3 CH 2- , CH 3 CH 2 CH 2- , CH 3 CH 2 CH 2 CH 2- ,
  • R 1 is a linear alkyl group having a fluorine atom, CF 3- , CF 3 CH 2- , CF 3 CF 2- , CF 3 CH 2 CH 2- , CF 3 CF 2 CH 2- , CF 3 CF 2 CF 2 - , CF 3 CH 2 CF 2 -, CF 3 CH 2 CH 2 CH 2 -, CF 3 CF 2 CH 2 CH 2 -, CF 3 CH 2 CF 2 CH 2 -, CF 3 CH 2 CF 2 CH 2 -, CF 3 CF 2 CF 2 CH 2- , CF 3 CF 2 CF 2 CF 2- , CF 3 CF 2 CH 2 CF 2- , CF 3 CH 2 CH 2 CH 2- , CF 3 CH 2 CF 2 CH 2 CH 2- , CF 3 CH 2 CF 2 CH 2 CH 2- , CF 3 CH 2 CF 2 CH 2 CH 2- , CF 3 CH 2 CF 2 CH 2 CH 2- , CF 3 CH 2 CF 2 CH 2 CH 2- ,
  • R 1 is a branched alkyl group having a fluorine atom
  • Etc. are preferably mentioned. However, since the viscosity is likely to be high when having a branch such as CH 3 -or CF 3- , it is more preferable that the number thereof is small (one) or zero.
  • R 2 is an alkylene group having 1 to 3 carbon atoms which may have a fluorine atom.
  • R 2 may be linear or branched.
  • An example of the minimum structural unit which comprises such a linear or branched alkylene group is shown below.
  • R 2 is composed of these alone or in combination.
  • R 2 is linear, it consists only of the above-mentioned linear minimum structural unit, and in particular, —CH 2 —, —CH 2 CH 2 — or —CF 2 — is preferable.
  • -CH 2 -or -CH 2 CH 2 - is more preferable because the solubility of the electrolyte salt can be further improved.
  • R 2 When R 2 is branched, it contains at least one of the branched minimum structural units described above, and has a general formula of-(CX a X b )-(X a is H, F , CH 3 or CF 3;.
  • X b is CH 3 or CF 3 provided that when X b is CF 3, X a is one represented by H or CH 3) it can be preferably exemplified. In particular, these can further improve the solubility of the electrolyte salt.
  • fluorinated alkyl groups are, for example, CF 3 CF 2- , HCF 2 CF 2- , H 2 CFCF 2- , CH 3 CF 2- , CF 3 CH 2- , CF 3 CF 2 CF 2- , HCF 2 CF 2 CF 2- , H 2 CFCF 2 CF 2- , CH 3 CF 2 CF 2- ,
  • fluorinated alkyl groups of Rf 2 and R 7 CF 3- , CF 3 CF 2- , (CF 3 ) 2 CH-, CF 3 CH 2- , C 2 F 5 CH 2- , CF 3 Preferred are CF 2 CH 2- , HCF 2 CF 2 CH 2- , CF 3 CFHCF 2 CH 2- , CFH 2- , and CF 2 H-, which have high flame retardancy and good rate characteristics and oxidation resistance.
  • CF 3 CH 2- , CF 3 CF 2 CH 2- , HCF 2 CF 2 CH 2- , CFH 2- , and CF 2 H- are more preferable.
  • R 7 is an alkyl group not containing a fluorine atom, it is an alkyl group having 1 to 7 carbon atoms. From the viewpoint of low viscosity, R 7 preferably has 1 to 4 carbon atoms, and more preferably 1 to 3 carbon atoms.
  • Examples of the above-mentioned alkyl group not containing a fluorine atom include CH 3- , CH 3 CH 2- , (CH 3 ) 2 CH-, C 3 H 7- and the like. Among them, CH 3 -and CH 3 CH 2 -are preferable in terms of low viscosity and good rate characteristics.
  • the fluorinated linear carbonate preferably has a fluorine content of 15 to 70% by mass.
  • the fluorine content is in the above-mentioned range, the compatibility with the solvent and the solubility of the salt can be maintained. 20 mass% or more is more preferable, 30 mass% or more is further more preferable, 35 mass% or more is especially preferable, 60 mass% or less is more preferable, and 50 mass% or less is still more preferable.
  • the fluorine content is based on the structural formula of the above-mentioned fluorinated linear carbonate, ⁇ (Number of fluorine atoms ⁇ 19) / molecular weight of fluorinated linear carbonate ⁇ ⁇ 100 (%) Is a value calculated by
  • the fluorinated linear carbonate is preferably any of the following compounds in view of low viscosity.
  • methyl 2,2,2-trifluoroethyl carbonate is particularly preferable.
  • the said fluorinated linear carbonate may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.
  • the content of the fluorinated linear carbonate is preferably 10 to 90% by volume, more preferably 40 to 85% by volume, with respect to the solvent. More preferably, it is 50 to 80% by volume.
  • the carboxylic acid ester may be a cyclic carboxylic acid ester or a linear carboxylic acid ester.
  • the cyclic carboxylic acid ester may be a non-fluorinated cyclic carboxylic acid ester or a fluorinated cyclic carboxylic acid ester.
  • non-fluorinated cyclic carboxylic acid esters examples include non-fluorinated saturated cyclic carboxylic acid esters, and preferred are non-fluorinated saturated cyclic carboxylic acid esters having an alkylene group of 2 to 4 carbon atoms.
  • non-fluorinated saturated cyclic carboxylic acid ester having an alkylene group having 2 to 4 carbon atoms include ⁇ -propiolactone, ⁇ -butyrolactone, ⁇ -caprolactone, ⁇ -valerolactone, ⁇ -methyl- ⁇ - Butyrolactone is mentioned. Among them, ⁇ -butyrolactone and ⁇ -valerolactone are particularly preferable in view of the improvement of the lithium ion dissociation degree and the improvement of the load characteristics.
  • the said non-fluorinated saturated cyclic carboxylic acid ester may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.
  • the content of the non-fluorinated saturated cyclic carboxylic acid ester is preferably 0 to 90% by volume with respect to the solvent, and 0.001 to 90 volumes. % Is more preferable, 1 to 60% by volume is further preferable, and 5 to 40% by volume is particularly preferable.
  • the chain carboxylic acid ester may be a non-fluorinated chain carboxylic acid ester or a fluorinated chain carboxylic acid ester.
  • non-fluorinated linear carboxylic acid ester examples include methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl propionate, ethyl propionate, propyl propionate, butyl propionate, tert-butyl propionate, tert.
  • butyl acetate, methyl propionate, ethyl propionate, propyl propionate and butyl propionate are preferable, and ethyl propionate and propyl propionate are particularly preferable.
  • the non-fluorinated linear carboxylic acid esters may be used alone or in any combination and ratio of two or more.
  • the content of the non-fluorinated linear carboxylic acid ester is preferably 0 to 90% by volume with respect to the solvent, and 0.001 to 90 volumes. % Is more preferable, 1 to 60% by volume is further preferable, and 5 to 40% by volume is particularly preferable.
  • the fluorinated linear carboxylic acid ester is a linear carboxylic acid ester having a fluorine atom.
  • the solvent containing the fluorinated linear carboxylic acid ester can be suitably used even under high voltage.
  • Rf 31 COORf 32 As said fluorinated linear carboxylic acid ester, the following general formula: Rf 31 COORf 32 (Wherein, R f 31 is a fluorinated alkyl group having 1 to 4 carbon atoms, R f 32 is an alkyl group optionally containing a fluorine atom having 1 to 4 carbon atoms), and a fluorinated linear carboxylic acid ester is It is preferable from the viewpoint of good compatibility with other solvents and oxidation resistance.
  • Rf 31 examples include HCF 2- , CF 3- , CF 3 CF 2- , HCF 2 CF 2- , CH 3 CF 2- , CF 3 CH 2- and the like, and among them, HCF 2- , CF 3- -, CF 3 CF 2 -and CF 3 CH 2 -are particularly preferable from the viewpoint of good viscosity and oxidation resistance.
  • Rf 32 for example, CH 3- , C 2 H 5- , CF 3- , CF 3 CF 2- , (CF 3 ) 2 CH-, CF 3 CH 2- , CF 3 CH 2 CH 2- , CF 3 3 CFHCF 2 CH 2 -, C 2 F 5 CH 2 -, CF 2 HCF 2 CH 2 -, C 2 F 5 CH 2 CH 2 -, CF 3 CF 2 CH 2 -, CF 3 CF 2 CF 2 CH 2 -
  • CH 3- , C 2 H 5- , CF 3 CH 2- , and CF 3 CH 2 CH 2 - are particularly preferable because of their good compatibility with other solvents.
  • CF 3 CH 2 C ( O) OCH 3
  • HCF 2 C ( O) OCH 3
  • HCF 2 C ( O) OC 2 H 5
  • CF 3 C ( O) OCH 2 C 2 F 5
  • CF 3 C ( O) OCH 2 CF 2 CF 2 H
  • CF 3 C ( O) OCH 2 CF 3
  • the said fluorinated linear carboxylic acid ester may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.
  • the content of the fluorinated linear carboxylic acid ester is preferably 10 to 90% by volume, preferably 40 to 85% by volume, with respect to the solvent. Is more preferable, and 50 to 80% by volume is even more preferable.
  • the solvent preferably contains at least one selected from the group consisting of the cyclic carbonate, the linear carbonate, and the linear carboxylic acid ester, and the cyclic carbonate, the linear carbonate, and the linear carboxylic acid. It is more preferable to include at least one selected from the group consisting of esters.
  • the cyclic carbonate is preferably a saturated cyclic carbonate.
  • the solvent contains the cyclic carbonate, and at least one selected from the group consisting of the linear carbonate and the linear carboxylic acid ester, the cyclic carbonate, the linear carbonate, and the linear carboxylic acid ester
  • the total content of at least one selected from the group consisting of 10 to 100% by volume is preferable, 30 to 100% by volume is more preferable, and 50 to 100% by volume is more preferable.
  • the solvent contains the cyclic carbonate, and at least one selected from the group consisting of the linear carbonate and the linear carboxylic acid ester, the cyclic carbonate, the linear carbonate, and the linear carboxylic acid ester
  • the volume ratio to at least one selected from the group consisting of is preferably 5/95 to 95/5, more preferably 10/90 or more, still more preferably 15/85 or more, and particularly preferably 20/80 or more. 90/10 or less is more preferable, 60/40 or less is further preferable, and 50/50 or less is particularly preferable.
  • the solvent preferably also contains at least one selected from the group consisting of the non-fluorinated saturated cyclic carbonate, the non-fluorinated linear carbonate, and the non-fluorinated linear carboxylic acid ester, and the non-fluorine It is more preferable to contain a fluorinated saturated cyclic carbonate and at least one selected from the group consisting of the above non-fluorinated linear carbonate and the above non-fluorinated linear carboxylic acid ester.
  • the electrolyte containing the solvent of the above composition can be suitably used for an electrochemical device used at a relatively low voltage.
  • the solvent contains the non-fluorinated saturated cyclic carbonate and at least one selected from the group consisting of the non-fluorinated linear carbonate and the non-fluorinated linear carboxylic acid ester
  • the non-fluorinated saturated cyclic It is preferable that a total of 5 to 100% by volume, preferably 20 to 100% by volume, of a carbonate and at least one selected from the group consisting of the above non-fluorinated linear carbonates and the above non-fluorinated linear carboxylic acid esters It is more preferable to contain, and it is further preferable to contain 30 to 100% by volume.
  • the electrolyte contains the non-fluorinated saturated cyclic carbonate and at least one selected from the group consisting of the non-fluorinated linear carbonate and the non-fluorinated linear carboxylic acid ester
  • the non-fluorinated saturation The volume ratio of the cyclic carbonate to at least one selected from the group consisting of the non-fluorinated linear carbonate and the non-fluorinated linear carboxylic acid ester is preferably 5/95 to 95/5, 10 / 90 or more is more preferable, 15/85 or more is further preferable, 20/80 or more is particularly preferable, 90/10 or less is more preferable, 60/40 or less is more preferable, 50/50 or less is particularly preferable.
  • the solvent preferably also contains at least one selected from the group consisting of the fluorinated saturated cyclic carbonate, the fluorinated linear carbonate, and the fluorinated linear carboxylic acid ester, and the fluorinated saturated cyclic carbonate It is more preferable to include at least one selected from the group consisting of the fluorinated linear carbonate and the fluorinated linear carboxylic acid ester.
  • the electrolyte containing the solvent of the above composition can be suitably used not only for electrochemical devices used at relatively low voltage but also for electrochemical devices used at relatively high voltage.
  • the solvent contains the fluorinated saturated cyclic carbonate, and at least one selected from the group consisting of the fluorinated chain carbonate and the fluorinated chain carboxylic acid ester, the fluorinated saturated cyclic carbonate
  • the total content of at least one selected from the group consisting of fluorinated linear carbonates and the above fluorinated linear carboxylic acid esters is preferably 5 to 100% by volume, and more preferably 10 to 100% by volume. It is more preferable to contain 30 to 100% by volume.
  • the solvent contains the fluorinated saturated cyclic carbonate, and at least one selected from the group consisting of the fluorinated chain carbonate and the fluorinated chain carboxylic acid ester
  • the fluorinated saturated cyclic carbonate is preferably 5/95 to 95/5, more preferably 10/90 or more, and 15 / 85 or more is more preferable, 20/80 or more is particularly preferable, 90/10 or less is more preferable, 60/40 or less is more preferable, and 50/50 or less is particularly preferable.
  • an ionic liquid can also be used as said solvent.
  • An "ionic liquid” is a liquid which consists of the ion which combined the organic cation and the anion.
  • the organic cation is not particularly limited, and examples thereof include imidazolium ions such as dialkylimidazolium cations and trialkylimidazolium cations; tetraalkylammonium ions; alkylpyridinium ions; dialkylpyrrolidinium ions; and dialkylpiperidinium ions .
  • the anion serving as the counter of these organic cations is not particularly limited.
  • the solvent is preferably a non-aqueous solvent
  • the electrolytic solution of the present invention is preferably a non-aqueous electrolytic solution.
  • the electrolytic solution of the present invention may further contain a compound (5) represented by the general formula (5).
  • a a + is a metal ion, a hydrogen ion or an onium ion, a is an integer of 1 to 3, b is an integer of 1 to 3, p is b / a, n 203 is an integer of 1 to 4, n 201 is An integer of 0 to 8, n 202 is 0 or 1, Z 201 is a transition metal, an element of group III, IV or V of the periodic table.
  • X 201 represents O, S, an alkylene group having 1 to 10 carbon atoms, a halogenated alkylene group having 1 to 10 carbon atoms, an arylene group having 6 to 20 carbon atoms, or a halogenated arylene group having 6 to 20 carbon atoms (alkylene group And the halogenated alkylene group, the arylene group and the halogenated arylene group may have a substituent or a hetero atom in the structure, and when n 202 is 1 and n 203 is 2 to 4, n 203 Each X 201 may be bonded).
  • L 201 represents a halogen atom, a cyano group, an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms, a halogenated aryl group having 6 to 20 carbon atoms
  • the alkylene group, the halogenated alkylene group, the arylene group and the halogenated arylene group may have a substituent or a hetero atom in the structure, and when n 201 is 2 to 8, n 201 L 201 is Each may combine to form a ring) or -Z 203 Y 203 .
  • Y 201, Y 202 and Z 203 are, O each independently, S, NY 204, hydrocarbon group or a fluorinated hydrocarbon group.
  • Y 203 and Y 204 each independently represent H, F, an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms or a halogen having 6 to 20 carbon atoms
  • Arylated aryl group (the alkyl group, the halogenated alkyl group, the aryl group and the halogenated aryl group may have a substituent or a hetero atom in the structure, and when a plurality of Y 203 or Y 204 exist, May combine to form a ring).
  • a a + is preferably a lithium ion, a sodium ion, a magnesium ion, a tetraalkylammonium ion or a hydrogen ion, and a lithium ion is particularly preferable.
  • the valence number a of the cation of A a + is an integer of 1 to 3. If it is more than 3, the crystal lattice energy becomes large, which causes a problem that dissolution in a solvent becomes difficult. Therefore, when solubility is required, 1 is more preferable.
  • the valence b of the anion is an integer of 1 to 3, and 1 is particularly preferable.
  • the constant p representing the ratio of cation to anion is necessarily determined by the ratio b / a of the two valences.
  • the ligand part of the general formula (5) will be described.
  • the organic or inorganic moiety bonded to Z 201 in the general formula (5) is referred to as a ligand.
  • Z 201 is preferably Al, B, V, Ti, Si, Zr, Ge, Sn, Cu, Y, Zn, Ga, Nb, Ta, Bi, P, As, Sc, Hf or Sb, Al , B or P is more preferable.
  • X 201 represents O, S, an alkylene group having 1 to 10 carbon atoms, a halogenated alkylene group having 1 to 10 carbon atoms, an arylene group having 6 to 20 carbon atoms, or a halogenated arylene group having 6 to 20 carbon atoms.
  • alkylene group and arylene group may have a substituent or a hetero atom in the structure.
  • a halogen atom instead of hydrogen on an alkylene group and an arylene group, a halogen atom, a chain or cyclic alkyl group, an aryl group, an alkenyl group, an alkoxy group, an aryloxy group, a sulfonyl group, an amino group, a cyano group, a carbonyl It may have a group, an acyl group, an amido group or a hydroxyl group as a substituent, or may have a structure in which nitrogen, sulfur or oxygen is introduced instead of carbon on alkylene and arylene.
  • n 202 is 1 and n 203 is 2 to 4, each of n 203 X 201 may be combined.
  • Such examples may include ligands such as ethylenediaminetetraacetic acid.
  • L 201 represents a halogen atom, a cyano group, an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms, a halogenated aryl group having 6 to 20 carbon atoms, -Z 203 Y 203 (Z 203 and Y 203 will be described later).
  • the alkyl group and the aryl group here may also have a substituent and a hetero atom in the structure, as in X 201, and when n 201 is 2 to 8, n 201 L 201 is each It may combine to form a ring.
  • a fluorine atom or a cyano group is preferable.
  • the solubility and the degree of dissociation of the salt of the anion compound are improved, and along with this, the ion conductivity is improved.
  • oxidation resistance improves and generation
  • Y 201, Y 202 and Z 203 are each independently, O, S, NY 204, hydrocarbon group, or an fluorinated hydrocarbon group.
  • Y 201 and Y 202 are preferably O, S or NY 204 , more preferably O.
  • these ligands constitute the Z 201 and chelate structure within the same ligand. The heat resistance, chemical stability and hydrolysis resistance of this compound are improved by the effect of this chelate.
  • n 202 in this ligand is 0 or 1, but in the case of 0, in particular, the chelating effect is a five-membered ring, and thus the chelating effect is most strongly exhibited and the stability is increased.
  • a fluorinated hydrocarbon group is a group in which at least one hydrogen atom of a hydrocarbon group is substituted by a fluorine atom.
  • Y 203 and Y 204 each independently represent H, F, an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms, or 6 to 20 carbon atoms It is a halogenated aryl group, and these alkyl group and aryl group may have a substituent or a hetero atom in the structure, and when two or more Y 203 or Y 204 exist, each is bonded To form a ring.
  • the constant n 203 related to the number of ligands described above is an integer of 1 to 4, preferably 1 or 2, and more preferably 2.
  • the constant n 201 related to the number of ligands described above is an integer of 0 to 8, preferably an integer of 0 to 4, and more preferably 0, 2 or 4. Furthermore, it is preferable that n 201 is 2 when n 203 is 1 and n 201 is 0 when n 203 is 2.
  • the alkyl group, the halogenated alkyl group, the aryl group and the halogenated aryl group also include those having other functional groups such as a branch, a hydroxyl group and an ether bond.
  • Examples of the compound (5) include lithium oxalato borate salts, and the following formula: Lithium bis (oxalato) borate (LIBOB) represented by the following formula: Lithium difluoro oxalato borate (LIDFOB),
  • Lithium difluoro oxalato phosphanite represented by the following formula: Lithium tetrafluoro oxalato phosphanite (LITFOP) represented by the following formula: And lithium bis (oxalato) difluorophosphanite and the like.
  • dicarboxylic acid complex salts in which the complex center element is boron include lithium bis (malonato) borate, lithium difluoro (malonato) borate, lithium bis (methyl malonato) borate, lithium difluoro (methyl malonato) borate, lithium bis ( Dimethyl malonato) borate, lithium difluoro (dimethyl malonato) borate and the like can be mentioned.
  • dicarboxylic acid complex salt in which the complex central element is phosphorus include lithium tris (oxalato) phosphate, lithium tris (malonato) phosphate, lithium difluorobis (malonato) phosphate, lithium tetrafluoro (malonato) phosphate and lithium tris Methylmalonato) phosphate, lithium difluorobis (methylmalonato) phosphate, lithium tetrafluoro (methylmalonato) phosphate, lithium tris (dimethylmalonato) phosphate, lithium difluorobis (dimethylmalonato) phosphate, lithium tetrafluoro (dimethylmalonato) phosphate etc. It can be mentioned.
  • LiAl (C 2 O 4 ) 2 LiAlF 2 (C 2 O 4 ), etc. may be mentioned.
  • lithium bis (oxalato) borate lithium difluoro (oxalato) borate, lithium tris (oxalato) phosphate, lithium difluorobis (oxalato) phosphate and lithium tetrafluoro (oxalato) phosphate are easy to obtain and have a stable film-like structure. From the point which can contribute to formation of a thing, it is used more suitably.
  • lithium bis (oxalato) borate is particularly preferable.
  • the content of the compound (5) is preferably 0.001% by mass or more, more preferably 0.01% by mass or more, and 10% by mass, with respect to the solvent, since further excellent cycle characteristics can be obtained. % Or less is preferable and 3 mass% or less is more preferable.
  • the electrolytic solution of the present invention preferably further contains an electrolyte salt (except for the compound (5)).
  • an electrolyte salt in addition to lithium salt, ammonium salt, metal salt, liquid salt (ionic liquid), inorganic polymer type salt, organic polymer type salt, etc. can be used for electrolyte solution Any thing can be used.
  • lithium salt is preferable.
  • Arbitrary things can be used as said lithium salt, The following are mentioned specifically.
  • Inorganic lithium salts such as LiPO 2 F 2 ; Lithium tungstates such as LiWOF 5 ; HCO 2 Li, CH 3 CO 2 Li, CH 2 FCO 2 Li, CHF 2 CO 2 Li, CF 3 CO 2 Li, CF 3 CH 2 CO 2 Li, CF 3 CF 2 CO 2 Li, CF 3 CF 2 CF 2 Carboxylic acid lithium salts such as CO 2 Li, CF 3 CF 2 CF 2 CO 2 Li; FSO 3 Li, CH 3 SO 3 Li, CH 2 FSO 3 Li, CHF
  • electrolyte salts may be used alone or in combination of two or more.
  • a preferable example in the case of using two or more in combination is a combined use of LiPF 6 and LiBF 4 or a combined use of LiPF 6 and LiPO 2 F 2 , C 2 H 5 OSO 3 Li or FSO 3 Li, and the high temperature storage characteristics There is an effect of improving load characteristics and cycle characteristics.
  • the blending amount of LiBF 4 , LiPO 2 F 2 , C 2 H 5 OSO 3 Li or FSO 3 Li with respect to 100% by mass of the whole electrolyte solution is not limited, and is optional unless the effects of the present invention are significantly impaired.
  • the amount is usually 0.01% by mass or more, preferably 0.1% by mass or more, and usually 30% by mass or less, preferably 20% by mass or less, more preferably 10% by mass, with respect to the electrolytic solution of the present invention. % Or less, more preferably 5% by mass or less.
  • Another example is the combined use of an inorganic lithium salt and an organic lithium salt, and the combined use of both has the effect of suppressing deterioration due to high temperature storage.
  • the organic lithium salt CF 3 SO 3 Li, LiN (FSO 2 ) 2 , LiN (FSO 2 ) (CF 3 SO 2 ), LiN (CF 3 SO 2 ) 2 , LiN (C 2 F 5 SO 2 ) 2 Lithium cyclic 1,2-perfluoroethanedisulfonyl imide lithium cyclic 1,3-perfluoropropane disulfonyl imide LiC (FSO 2 ) 3 LiC (CF 3 SO 2 ) 3 LiC (C 2 F 5 SO 2 ) 2 ) 3 , LiBF 3 CF 3 , LiBF 3 C 2 F 5 , LiPF 3 (CF 3 ) 3 , LiPF 3 (C 2 F 5 ) 3 or the like.
  • the ratio of the organic lithium salt to the total 100% by mass of the electrolyte is preferably 0.1% by mass or more, particularly preferably 0.5% by mass or more, and preferably 30% by mass or less, particularly preferably Preferably it is 20 mass% or less.
  • the concentration of these electrolyte salts in the electrolyte is not particularly limited as long as the effects of the present invention are not impaired.
  • the total molar concentration of lithium in the electrolytic solution is preferably 0.3 mol / L or more, and more preferably 0.4 mol / L, in order to set the electric conductivity of the electrolytic solution in a good range and to ensure good battery performance.
  • the amount is more preferably 0.5 mol / L or more, preferably 3 mol / L or less, more preferably 2.5 mol / L or less, and still more preferably 2.0 mol / L or less.
  • the electrical conductivity of the electrolyte may be insufficient.
  • the concentration is too high, the electrical conductivity may decrease due to the increase in viscosity, and the battery performance may decrease. May.
  • ammonium salt is preferable as the electrolyte salt of the electrolytic solution for an electric double layer capacitor.
  • ammonium salt include the following (IIa) to (IIe).
  • (IIa) Tetraalkyl quaternary ammonium salt General formula (IIa):
  • R 1a , R 2a , R 3a and R 4a are the same or different, and each may be an alkyl group containing an ether bond of 1 to 6 carbon atoms; X - is an anion)
  • tetraalkyl quaternary ammonium salts represented by the following.
  • those in which a part or all of hydrogen atoms of this ammonium salt is substituted with a fluorine atom and / or a fluorine-containing alkyl group having 1 to 4 carbon atoms are also preferable from the viewpoint of improving the oxidation resistance.
  • R 5a is an alkyl group having 1 to 6 carbon atoms;
  • R 6a is a divalent hydrocarbon group having 1 to 6 carbon atoms;
  • R 7a is an alkyl group having 1 to 4 carbon atoms;
  • z is 1 or 2;
  • X - is an anion
  • the anion X ⁇ may be an inorganic anion or an organic anion.
  • examples of the inorganic anion include AlCl 4 ⁇ , BF 4 ⁇ , PF 6 ⁇ , AsF 6 ⁇ , TaF 6 ⁇ , I ⁇ , and SbF 6 ⁇ .
  • organic anion examples include bisoxalatoborate anion, difluorooxalatoborate anion, tetrafluorooxalatophosphate anion, difluorobisoxalatophosphate anion, CF 3 COO ⁇ , CF 3 SO 3 ⁇ , (CF 3 SO 2 ) 2 N ⁇ , (C 2 F 5 SO 2 ) 2 N ⁇ , and the like.
  • BF 4 ⁇ , PF 6 ⁇ , AsF 6 ⁇ , and SbF 6 ⁇ are preferable from the viewpoint of good oxidation resistance and ion dissociation.
  • Preferred specific examples of the tetraalkyl quaternary ammonium salt include Et 4 NBF 4 , Et 4 NClO 4 , Et 4 NPF 6 , Et 4 NAsF 6 , Et 4 NSbF 6 , Et 4 NCF 3 SO 3 , Et 4 N ( CF 3 SO 2 ) 2 N, Et 4 NC 4 F 9 SO 3 , Et 3 MeNBF 4 , Et 3 MeNClO 4 , Et 3 MeNPF 6 , Et 3 MeNAsF 6 , Et 3 MeNSbF 6 , Et 3 MeNCF 3 SO 3 , Et 3 3 MeN (CF 3 SO 2 ) 2 N, Et 3 MeNC 4 F 9 SO 3 may be used, and in particular, Et 4 NBF 4 , Et 4 NPF 6 , Et 4 NSbF 6 , Et 4 NAsF 6 , Et 3 MeNBF 4 , N, N-diethyl-N-methyl-N- (2-methoxyethyl) ammonium salt etc.
  • R 8a and R 9a are the same or different and each is an alkyl group having 1 to 4 carbon atoms; X - is an anion; n 1 is an integer of 0 to 5; n 2 is an integer of 0 to 5)
  • R 10a and R 11a are the same or different and each is an alkyl group of 1 to 4 carbon atoms; X - is an anion; n 3 is an integer of 0 to 5; n 4 is an integer of 0 to 5) Or a spirocyclic bipyrrolidinium salt represented by the general formula (IIb-3):
  • R 12a and R 13a are the same or different and each is an alkyl group having 1 to 4 carbon atoms; X - is an anion; n 5 is an integer of 0 to 5; n 6 is an integer of 0 to 5)
  • the spiro ring bipyrrolidinium salt shown by these is mentioned preferably. Further, those in which part or all of the hydrogen atoms of this spirocyclic bipyrrolidinium salt are substituted with a fluorine atom and / or a fluorine-containing alkyl group having 1 to 4 carbon atoms are also preferable from the viewpoint of improving the oxidation resistance.
  • Anion X - of the preferred embodiment are the same as for (IIa). Among them, high dissociative, terms the internal resistance is low under a high voltage, BF 4 -, PF 6 - , (CF 3 SO 2) 2 N- or (C 2 F 5 SO 2) 2 N- is preferable.
  • Preferred specific examples of the spirocyclic bipyrrolidinium salt include, for example, Etc.
  • the spirocyclic bipyrrolidinium salt is excellent in solubility in solvents, oxidation resistance, and ion conductivity.
  • R 14a and R 15a are the same or different, and each is an alkyl group having 1 to 6 carbon atoms; X - is an anion)
  • the imidazolium salt shown by these can be illustrated preferably. Further, those in which part or all of hydrogen atoms of this imidazolium salt is substituted with a fluorine atom and / or a fluorine-containing alkyl group having 1 to 4 carbon atoms are also preferable from the viewpoint of improving the oxidation resistance.
  • Anion X - of the preferred embodiment is the same as (IIa).
  • This imidazolium salt is excellent in that it has low viscosity and good solubility.
  • N-alkyl pyridinium salt represented by can be preferably exemplified. Further, it is also preferable from the viewpoint that the oxidation resistance is improved, in which part or all of hydrogen atoms of this N-alkylpyridinium salt is substituted by a fluorine atom and / or a fluorine-containing alkyl group having 1 to 4 carbon atoms.
  • Anion X - of the preferred embodiment is the same as (IIa).
  • This N-alkylpyridinium salt is excellent in that it has low viscosity and good solubility.
  • N, N-dialkyl pyrrolidinium salt represented by can be preferably exemplified.
  • oxidation resistance is also improved in the case where part or all of the hydrogen atoms of this N, N-dialkylpyrrolidinium salt is substituted with a fluorine atom and / or a fluorine-containing alkyl group having 1 to 4 carbon atoms. It is preferable from the point of view.
  • Anion X - of the preferred embodiment is the same as (IIa).
  • This N, N-dialkylpyrrolidinium salt is excellent in that it has low viscosity and good solubility.
  • ammonium salts (IIa), (IIb) and (IIc) are preferable in terms of good solubility, oxidation resistance and ion conductivity, and further preferred
  • a lithium salt may be used as an electrolyte salt for an electric double layer capacitor.
  • the lithium salt LiPF 6, LiBF 4, LiN (FSO 2) 2, LiAsF 6, LiSbF 6, LiN (SO 2 C 2 H 5) 2 is preferred.
  • Magnesium salts may be used to further improve the capacity.
  • the magnesium salt e.g., Mg (ClO 4) 2, Mg (OOC 2 H 5) 2 and the like are preferable.
  • the concentration is preferably 0.7 mol / l or more. If the amount is less than 0.7 mol / liter, not only the low temperature characteristics may be deteriorated, but also the initial internal resistance may be increased.
  • the concentration of the electrolyte salt is more preferably 0.9 mol / l or more.
  • the upper limit of the concentration is preferably 2.0 mol / l or less, more preferably 1.5 mol / l or less, in terms of low temperature characteristics.
  • the concentration is preferably 0.7 to 1.5 mol / l in terms of excellent low temperature characteristics. In the case of spirobipyrrolidinium tetrafluoride (SBPBF 4 ), it is preferably 0.7 to 2.0 mol / liter.
  • the electrolytic solution of the present invention has the general formula (2): (Wherein, X 21 is a group containing at least H or C, n 21 is an integer of 1 to 3, Y 21 and Z 21 are the same or different, a group containing at least H, C, O or F, n 22 Preferably further includes a compound (2) shown by 0), 1 and Y 21 and Z 21 may be bonded to each other to form a ring).
  • the electrolytic solution contains the compound (2), the capacity retention ratio is less likely to be further reduced even when stored at high temperature, and the amount of gas generation is less likely to be further increased.
  • n 21 is 2 or 3
  • two or three X 21 s may be the same or different.
  • the plurality of Y 21 and Z 21 may be the same or different.
  • H-, F-, CH 3- , CH 3 CH 2- , CH 3 CH 2 CH 2- , CF 3- , CF 3 CF 2- , CH 2 FCH 2 -and CF 3 CF 2 CF At least one selected from the group consisting of 2- is preferred.
  • Z 21 H-, F-, CH 3- , CH 3 CH 2- , CH 3 CH 2 CH 2- , CF 3- , CF 3 CF 2- , CH 2 FCH 2 -and CF 3 CF 2 CF At least one selected from the group consisting of 2- is preferred.
  • Y 21 and Z 21 may be bonded to each other to form a carbocyclic or heterocyclic ring which may contain an unsaturated bond and which may have aromaticity.
  • the number of carbon atoms in the ring is preferably 3 to 20.
  • analog refers to an acid anhydride obtained by replacing a part of the structure of the exemplified acid anhydride with another structure without departing from the spirit of the present invention.
  • the acid anhydride having a five-membered ring structure examples include succinic anhydride, methyl succinic anhydride (4-methyl succinic anhydride), and dimethyl succinic anhydride (4, 4-dimethyl succinic anhydride) , 4,5-dimethylsuccinic anhydride etc.), 4,4,5-trimethylsuccinic anhydride, 4,4,5,5-tetramethylsuccinic anhydride, 4-vinylsuccinic anhydride, 4,5 -Divinylsuccinic anhydride, phenylsuccinic anhydride (4-phenylsuccinic anhydride), 4,5-diphenylsuccinic anhydride, 4,4-diphenylsuccinic anhydride, citraconic anhydride, maleic anhydride, Methylmaleic anhydride (4-methylmaleic anhydride), 4,5-dimethylmaleic anhydride, phenylmaleic anhydride (4-phenylmaleic
  • the acid anhydride having a 6-membered ring structure include cyclohexanedicarboxylic acid anhydride (cyclohexane-1,2-dicarboxylic acid anhydride etc.), 4-cyclohexene-1,2-dicarboxylic acid anhydride, Examples thereof include glutaric anhydride, glutaconic anhydride, 2-phenylglutaric anhydride and the like, and analogs thereof.
  • acid anhydride forming the cyclic structure 5-norbornene-2,3-dicarboxylic acid anhydride, cyclopentanetetracarboxylic acid dianhydride, pyromellitic acid anhydride, diglycolic acid anhydride And their analogues.
  • acid anhydride which forms a cyclic structure and is substituted by a halogen atom examples include monofluorosuccinic anhydride (4-fluorosuccinic anhydride and the like), 4,4-difluorosuccinic anhydride, , 5-Difluorosuccinic anhydride, 4,4,5-trifluorosuccinic anhydride, trifluoromethylsuccinic anhydride, tetrafluorosuccinic anhydride (4,4,5,5-tetrafluorosuccinic anhydride ), 4-fluoromaleic anhydride, 4,5-difluoromaleic anhydride, trifluoromethylmaleic anhydride, 5-fluoroitaconic anhydride, 5,5-difluoroitaconic anhydride, etc. And the like.
  • glutaric anhydride citraconic anhydride, glutaconic anhydride, itaconic anhydride, diglycolic anhydride, cyclohexanedicarboxylic acid anhydride, cyclopentanetetracarboxylic acid dianhydride, 4-cyclohexene- 1,2-dicarboxylic acid anhydride, 3,4,5,6-tetrahydrophthalic acid anhydride, 5-norbornene-2,3-dicarboxylic acid anhydride, phenyl succinic acid anhydride, 2-phenyl glutaric acid anhydride, Maleic anhydride, methylmaleic anhydride, trifluoromethylmaleic anhydride, phenylmaleic anhydride, succinic anhydride, methylsuccinic anhydride, dimethylsuccinic anhydride, trifluoromethylsuccinic anhydride, monofluorosuccinic anhydride Acid anhydride, te
  • the compound (2) is represented by the general formula (3):
  • X 31 to X 34 are the same or different and each is a group containing at least H, C, O or F), a compound (3), and a compound represented by the general formula (4):
  • X 41 and X 42 are the same or different and is preferably at least one selected from the group consisting of compounds (4) represented by a group containing at least H, C, O or F) .
  • X 31 to X 34 at least one selected from the group consisting of an alkyl group, a fluorinated alkyl group, an alkenyl group and a fluorinated alkenyl group, which may be the same or different, is preferable.
  • the carbon number of X 31 to X 34 is preferably 1 to 10, and more preferably 1 to 3.
  • H-, F-, CH 3- , CH 3 CH 2- , CH 3 CH 2 CH 2- , CF 3- , CF 3 CF 2- , CH 2 FCH 2 - and CF 3 CF 2 CF 2 - at least one member selected from the group consisting of is more preferable.
  • X 41 and X 42 at least one selected from the group consisting of an alkyl group, a fluorinated alkyl group, an alkenyl group and a fluorinated alkenyl group, which may be the same or different, is preferable.
  • the number of carbon atoms of X 41 and X 42 is preferably 1 to 10, 1 to 3 more preferred.
  • H-, F-, CH 3- , CH 3 CH 2- , CH 3 CH 2 CH 2- , CF 3- , CF 3 CF 2- , CH 2 FCH 2 - and CF 3 CF 2 CF 2 - at least one member selected from the group consisting of is more preferable.
  • the compound (3) is preferably any of the following compounds.
  • the compound (4) is preferably any of the following compounds.
  • the content of the compound (2) is more preferably 0.01 to 10% by mass, still more preferably 0.1 to 3% by mass, and particularly preferably 0.1 to 1.0% by mass.
  • the electrolytic solution contains both the compounds (3) and (4), the capacity retention is less likely to decrease even when stored at high temperatures, and the amount of gas generation is further difficult to increase.
  • 0.08 to 2.50% by mass of the compound (3) and 0.02 to 1.50% by mass of the compound (4) based on the electrolytic solution preferably 0.80 to 2.50. More preferably, the composition contains 3% by mass of the compound (3) and 0.08 to 1.50% by mass of the compound (4).
  • the electrolytic solution of the present invention may contain at least one selected from the group consisting of nitrile compounds represented by the following general formulas (1a), (1b) and (1c).
  • R a and R b each independently represent a hydrogen atom, a cyano group (CN), a halogen atom, an alkyl group, or a group obtained by substituting at least a part of hydrogen atoms of an alkyl group with a halogen atom N represents an integer of 1 to 10.
  • R c is a hydrogen atom, a halogen atom, an alkyl group, a group obtained by substituting at least a part of hydrogen atoms of the alkyl group with a halogen atom, or NC-R c1 -X c1- (R c is an alkylene group And X c1 represents an oxygen atom or a sulfur atom
  • R d and R e each independently represent at least a part of a hydrogen atom, a halogen
  • R a and R b each independently represent a hydrogen atom, a cyano group (CN), a halogen atom, an alkyl group, or a hydrogen atom of at least part of the alkyl group as a halogen atom It is a substituted group.
  • a halogen atom a fluorine atom, a chlorine atom, a bromine atom, an iodine atom is mentioned, for example. Among them, a fluorine atom is preferable.
  • the alkyl group is preferably one having 1 to 5 carbon atoms.
  • alkyl group examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group and a tert-butyl group.
  • a group which substituted at least one hydrogen atom of the alkyl group by the halogen atom a group which substituted at least one hydrogen atom of the above-mentioned alkyl group by the above-mentioned halogen atom can be mentioned.
  • R a and R b are an alkyl group or a group obtained by substituting at least a part of hydrogen atoms of an alkyl group with a halogen atom
  • R a and R b are bonded to each other to form a ring structure (eg cyclohexane ring ) May be formed.
  • R a and R b are preferably a hydrogen atom or an alkyl group.
  • n is an integer of 1 to 10.
  • n pieces of R a may be the same for all, it may be at least partially different.
  • R b is preferably an integer of 1 to 7, and more preferably an integer of 2 to 5.
  • dinitrile and tricarbonitrile are preferable.
  • the dinitrile include malononitrile, succinonitrile, glutaronitrile, adiponitrile, pimeronitrile, suberonitrile, azera nitrile, sebaconitrile, undecane dinitrile, dodecane dinitrile, methyl malononitrile, ethyl malononitrile, isopropyl malononitrile, tert-butyl Malononitrile, methyl succinonitrile, 2, 2-dimethyl succinonitrile, 2,3- dimethyl succinonitrile, 2, 3, 3- trimethyl succinonitrile, 2, 2, 3, 3- tetramethyl succinonitrile 2,3-Diethyl-2,3-dimethylsuccinonitrile, 2,2-diethyl-3,3-dimethylsuccinonitrile, bicyclohexyl-1,1-d
  • succinonitrile glutaronitrile and adiponitrile.
  • tricarbonitrile include pentane tricarbonitrile, propane tricarbonitrile, 1,3,5-hexane tricarbonitrile, 1,3,6-hexane tricarbonitrile, heptane tricarbonitrile, 2,3-propanetricarbonitrile, 1,3,5-pentanetricarbonitrile, cyclohexanetricarbonitrile, triscyanoethylamine, triscyanoethoxypropane, tricyanoethylene, tris (2-cyanoethyl) amine and the like
  • 1,3,6-hexane tricarbonitrile and cyclohexane tricarbonitrile and most preferred is cyclohexane tricarbonitrile.
  • R c is a hydrogen atom, a halogen atom, an alkyl group, a group obtained by substituting at least a part of the hydrogen atoms of the alkyl group with a halogen atom, or NC-R c1 -X c1- (R c1 is an alkylene group, and X c1 is a group represented by an oxygen atom or a sulfur atom.)
  • R d and R e each independently represent a hydrogen atom, a halogen atom, an alkyl group, or an alkyl group Are groups in which at least a part of hydrogen atoms are substituted by halogen atoms.
  • halogen atom examples include those exemplified for the above general formula (1a).
  • the NC-R c1 -X c1 - in R c1 is an alkylene group.
  • the alkylene group an alkylene group having 1 to 3 carbon atoms is preferable.
  • Each of R c , R d and R e is preferably independently a hydrogen atom, a halogen atom, an alkyl group, or a group obtained by substituting at least a part of hydrogen atoms of an alkyl group with a halogen atom.
  • At least one of R c , R d and R e is preferably a halogen atom or a group obtained by substituting at least a part of hydrogen atoms of an alkyl group with a halogen atom, and at least one of a fluorine atom or an alkyl group It is more preferable that it is a group in which a part of hydrogen atoms is substituted by a fluorine atom.
  • R d and R e are an alkyl group or a group obtained by substituting at least a part of hydrogen atoms of an alkyl group with a halogen atom, R d and R e are bonded to each other to form a ring structure (eg, cyclohexane ring ) May be formed.
  • a ring structure eg, cyclohexane ring
  • m is an integer of 1 to 10.
  • the m Rds may be all the same or at least partially different.
  • m is preferably an integer of 2 to 7, and more preferably an integer of 2 to 5.
  • nitrile compound represented by the above general formula (1b) acetonitrile, propionitrile, butyronitrile, isobutyronitrile, valeronitrile, isovaleronitrile, lauronitrile, 3-methoxypropionitrile, 2-methylbutyro ro Nitrile, trimethylacetonitrile, hexanenitrile, cyclopentanecarbonitrile, cyclohexanecarbonitrile, fluoroacetonitrile, difluoroacetonitrile, trifluoroacetonitrile, 2-fluoropropionitrile, 3-fluoropropionitrile, 2,2-difluoropropionitrile, 2,3-Difluoropropionitrile, 3,3-difluoropropionitrile, 2,2,3-trifluoropropionitrile, 3,3,3-trifluoropropionitrile, 3 3'-oxy dipropionate nitrile, 3,3' thiodipropion
  • R f , R g , R h and R i each independently represent at least a group including a cyano group (CN), a hydrogen atom, a halogen atom, an alkyl group or an alkyl group. It is a group in which a part of hydrogen atoms is replaced by a halogen atom.
  • CN cyano group
  • the halogen atom, the alkyl group, and the group in which at least a part of hydrogen atoms of the alkyl group is substituted with a halogen atom include those exemplified for the above general formula (1a).
  • R f , R g , R h and R i are a group containing a cyano group.
  • R f , R g , R h and R i are a group containing a cyano group.
  • R f and R g are preferably a hydrogen atom.
  • l is an integer of 1 to 3.
  • l R f may be all the same or at least a part may be different.
  • R g is preferably an integer of 1 to 2.
  • nitrile compound represented by the above general formula (1c) 3-hexenedinonitrile, mucononitrile, maleonitrile, fumaronitrile, acrylonitrile, methacrylonitrile, crotononitrile, 3-methylcrotononitrile, 2-methyl-2- Examples thereof include butenenitrile, 2-pentenenitrile, 2-methyl-2-pentenenitrile, 3-methyl-2-pentenenitrile, 2-hexenenitrile and the like, and 3-hexene dinitrile and mucononitrile are preferable, and 3-hexene di particular Nitriles are preferred.
  • the content of the nitrile compound is preferably 0.2 to 7% by mass with respect to the electrolytic solution. This can further improve the high temperature storage characteristics and safety of the electrochemical device at high voltage.
  • the lower limit of the total content of the nitrile compound is more preferably 0.3% by mass, and still more preferably 0.5% by mass.
  • the upper limit is more preferably 5% by mass, still more preferably 2% by mass, and particularly preferably 0.5% by mass.
  • the electrolytic solution of the present invention may contain a compound having an isocyanato group (hereinafter sometimes abbreviated as "isocyanate”). It does not specifically limit as said isocyanate, Arbitrary isocyanate can be used. Examples of the isocyanate include monoisocyanates, diisocyanates, triisocyanates and the like.
  • monoisocyanates include isocyanatomethane, isocyanatoethane, 1-isocyanatopropane, 1-isocyanatobutane, 1-isocyanatopentane, 1-isocyanatohexane, 1-isocyanatoheptane, 1-isocyanate.
  • diisocyanates include 1,4-diisocyanatobutane, 1,5-diisocyanatopentane, 1,6-diisocyanatohexane, 1,7-diisocyanatoheptane, 1,8-diisocyanate Natooctane, 1,9-diisocyanatononane, 1,10-diisocyanatodecane, 1,3-diisocyanatopropene, 1,4-diisocyanato-2-butene, 1,4-diisocyanato-2-fluorobutane 1,4-diisocyanato-2,3-difluorobutane, 1,5-diisocyanato-2-pentene, 1,5-diisocyanato-2-methylpentane, 1,6-diisocyanato-2-hexene, 1,6-diisocyanato -3-hexene, 1,6-diisocyan
  • triisocyanates include 1,6,11-triisocyanatoundecane, 4-isocyanatomethyl-1,8-octamethylene diisocyanate, 1,3,5-triisocyanatomethylbenzene, 1,3,5 -Tris (6-isocyanatohex-1-yl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione, 4- (isocyanatomethyl) octamethylene diisocyanate etc. It can be mentioned.
  • 1,6-diisocyanatohexane, 1,3-bis (isocyanatomethyl) cyclohexane, 1,3,5-tris (6-isocyanatohexa-1-yl) -1,3,5-triazine- 2,4,6 (1H, 3H, 5H) -trione, 2,4,4-trimethylhexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate are industrially easy to obtain It is preferable in that the production cost of the electrolytic solution can be kept low, and from the technical point of view it can contribute to the formation of a stable film-like structure and is more preferably used.
  • the content of the isocyanate is not particularly limited and is optional as long as the effects of the present invention are not significantly impaired, but the content is preferably 0.001% by mass or more and 1.0% by mass or less with respect to the electrolytic solution.
  • the content of the isocyanate is at least the lower limit, the non-aqueous electrolyte secondary battery can have a sufficient effect of improving the cycle characteristics. Moreover, the initial stage resistance increase of a non-aqueous electrolyte solution secondary battery can be avoided as it is below this upper limit.
  • the content of isocyanate is more preferably 0.01% by mass or more, still more preferably 0.1% by mass or more, particularly preferably 0.2% by mass or more, and more preferably 0.8% by mass or less, more preferably Is at most 0.7% by mass, particularly preferably at most 0.6% by mass.
  • the electrolytic solution of the present invention may contain a cyclic sulfonic acid ester.
  • the cyclic sulfonic acid ester is not particularly limited, and any cyclic sulfonic acid ester can be used.
  • Examples of cyclic sulfonic acid esters include saturated cyclic sulfonic acid esters, unsaturated cyclic sulfonic acid esters, saturated cyclic disulfonic acid esters, unsaturated cyclic disulfonic acid esters and the like.
  • saturated cyclic sulfonic acid ester examples include 1,3-propane sultone, 1-fluoro-1,3-propane sultone, 2-fluoro-1,3-propane sultone, 3-fluoro-1,3-propane sultone 1-methyl-1,3-propanesultone, 2-methyl-1,3-propanesultone, 3-methyl-1,3-propanesultone, 1,3-butanesultone, 1,4-butanesultone, 1-fluoro-, 1,4-butane sultone, 2-fluoro-1,4-butane sultone, 3-fluoro-1,4-butane sultone, 4-fluoro-1,4-butane sultone, 1-methyl-1,4-butane sultone, 2-methyl- 1,4-butane sultone, 3-methyl-1,4-butane sultone, 4-methyl-1,4-butane sultone, 2,4-butan
  • unsaturated cyclic sulfonic acid ester examples include 1-propene-1,3-sultone, 2-propene-1,3-sultone, 1-fluoro-1-propene-1,3-sultone, 2-fluoro- 1-propene-1,3-sultone, 3-fluoro-1-propene-1,3-sultone, 1-fluoro-2-propene-1,3-sultone, 2-fluoro-2-propene-1,3- Sultone, 3-fluoro-2-propene-1,3-sultone, 1-methyl-1-propene-1,3-sultone, 2-methyl-1-propene-1,3-sultone, 3-methyl-1- Propene-1,3-sultone, 1-methyl-2-propene-1,3-sultone, 2-methyl-2-propene-1,3-sultone, 3-methyl-2-propene-1,3-sultone, 1-butene-1, -Sultone, 2-butene-1,4-
  • 1,3-propane sultone, 1-fluoro-1,3-propane sultone, 2-fluoro-1,3-propane sultone, 3-fluoro-1,3-propane sultone, 1-propene-1,3- Sultone is more preferably used in that it can contribute to the availability and formation of a stable film-like structure.
  • the content of the cyclic sulfonic acid ester is not particularly limited and is optional as long as the effects of the present invention are not significantly impaired, but preferably 0.001% by mass or more and 3.0% by mass or less with respect to the electrolytic solution. is there.
  • the content of the cyclic sulfonic acid ester is more preferably 0.01% by mass or more, still more preferably 0.1% by mass or more, particularly preferably 0.2% by mass or more, and more preferably 2.5% by mass or less More preferably, it is at most 2.0 mass%, particularly preferably at most 1.8 mass%.
  • the electrolytic solution of the present invention may further contain polyethylene oxide having a weight average molecular weight of 2000 to 4000 and having -OH, -OCOOH or -COOH at the end.
  • polyethylene oxide having a weight average molecular weight of 2000 to 4000 and having -OH, -OCOOH or -COOH at the end.
  • polyethylene oxide monool, polyethylene oxide carboxylic acid, polyethylene oxide diol, polyethylene oxide dicarboxylic acid, polyethylene oxide triol, polyethylene oxide tricarboxylic acid etc. are mentioned, for example. These may be used alone or in combination of two or more. Among them, a mixture of polyethylene oxide monool and polyethylene oxide diol, and a mixture of polyethylene carboxylic acid and polyethylene dicarboxylic acid are preferable in that the characteristics of the electrochemical device become better.
  • the weight average molecular weight of the above-mentioned polyethylene oxide is too small, there is a possibility that it is easy to be oxidatively decomposed.
  • the weight average molecular weight is more preferably 3,000 to 4,000.
  • the said weight average molecular weight can be measured by polystyrene conversion by gel permeation chromatography (GPC) method.
  • the content of the polyethylene oxide is preferably 1 ⁇ 10 ⁇ 6 to 1 ⁇ 10 ⁇ 2 mol / kg in the electrolytic solution. If the content of the polyethylene oxide is too high, the properties of the electrochemical device may be impaired.
  • the content of the polyethylene oxide is more preferably 5 ⁇ 10 ⁇ 6 mol / kg or more.
  • the electrolytic solution of the present invention may further contain, as an additive, a fluorinated saturated cyclic carbonate, an unsaturated cyclic carbonate, an overcharge inhibitor, other known auxiliary agents and the like. Thereby, the deterioration of the characteristics of the electrochemical device can be suppressed.
  • fluorinated saturated cyclic carbonate examples include the compounds represented by the general formula (A) described above. Among them, fluoroethylene carbonate, 4,5-difluoro-1,3-dioxolan-2-one, 2,2,3,3,3-pentafluoropropyl ethylene carbonate (4- (2,2,3,3, 3-Pentafluoro-propyl)-[1,3] dioxolan-2-one) is preferred.
  • the fluorinated saturated cyclic carbonate may be used alone or in any combination of two or more in any proportion.
  • the content of the fluorinated saturated cyclic carbonate is preferably 0.001 to 10% by mass, more preferably 0.01 to 5% by mass, with respect to the electrolytic solution. More preferably, it is mass%.
  • unsaturated cyclic carbonates examples include vinylene carbonates, ethylene carbonates substituted with a substituent having an aromatic ring or a carbon-carbon double bond or a carbon-carbon triple bond, phenyl carbonates, vinyl carbonates, allyl carbonates, And catechol carbonates.
  • vinylene carbonates vinylene carbonate, methylvinylene carbonate, 4,5-dimethylvinylene carbonate, phenylvinylene carbonate, 4,5-diphenylvinylene carbonate, vinylvinylene carbonate, 4,5-divinylvinylene carbonate, allylvinylene carbonate, 4 , 5-diallylvinylene carbonate, 4-fluorovinylene carbonate, 4-fluoro-5-methylvinylene carbonate, 4-fluoro-5-phenylvinylene carbonate, 4-fluoro-5-vinylvinylene carbonate, 4-allyl-5-fluoro Vinylene carbonate, ethynyl ethylene carbonate, propargyl ethylene carbonate, methyl vinylene carbonate, dimethyl vinylene carbonate, etc. It is below.
  • ethylene carbonates substituted with a substituent having an aromatic ring or a carbon-carbon double bond or a carbon-carbon triple bond include vinyl ethylene carbonate, 4,5-divinyl ethylene carbonate, 4-methyl-5- Vinyl ethylene carbonate, 4-allyl-5-vinyl ethylene carbonate, ethynyl ethylene carbonate, 4,5-diethynyl ethylene carbonate, 4-methyl-5-ethynyl ethylene carbonate, 4-vinyl-5-ethynyl ethylene carbonate, 4-allyl -5-ethynyl ethylene carbonate, phenyl ethylene carbonate, 4,5-diphenyl ethylene carbonate, 4-phenyl-5-vinyl ethylene carbonate, 4-allyl-5-phenyl ethylene carbonate, allyl ethylene carbonate 4,5-Diallylethylene carbonate, 4-methyl-5-allylethylene carbonate, 4-methylene-1,3-dioxolan-2-one, 4,5-dimethylene-1,3-(2-
  • the molecular weight of the unsaturated cyclic carbonate is not particularly limited, and is arbitrary unless the effects of the present invention are significantly impaired.
  • the molecular weight is preferably 50 or more and 250 or less. Within this range, the solubility of the unsaturated cyclic carbonate in the electrolytic solution can be easily secured, and the effects of the present invention can be sufficiently exhibited.
  • the molecular weight of the unsaturated cyclic carbonate is more preferably 80 or more, and more preferably 150 or less.
  • the method for producing the unsaturated cyclic carbonate is not particularly limited, and any known method can be selected for production.
  • the unsaturated cyclic carbonates may be used alone or in any combination of two or more in any proportion.
  • the content of the unsaturated cyclic carbonate is not particularly limited, and is arbitrary unless the effects of the present invention are significantly impaired.
  • the content of the unsaturated cyclic carbonate is preferably 0.001% by mass or more, more preferably 0.01% by mass or more, and still more preferably 0.1% by mass or more in 100% by mass of the electrolytic solution.
  • the content is preferably 5% by mass or less, more preferably 4% by mass or less, and still more preferably 3% by mass or less.
  • the unsaturated cyclic carbonate in addition to the non-fluorinated unsaturated cyclic carbonate as described above, a fluorinated unsaturated cyclic carbonate can also be suitably used.
  • the fluorinated unsaturated cyclic carbonate is a cyclic carbonate having an unsaturated bond and a fluorine atom.
  • the number of fluorine atoms in the fluorinated unsaturated cyclic carbonate is not particularly limited as long as it is 1 or more. Among them, the number of fluorine atoms is usually 6 or less, preferably 4 or less, and one or two are most preferable.
  • fluorinated unsaturated cyclic carbonate examples include fluorinated vinylene carbonate derivatives, fluorinated ethylene carbonate derivatives substituted with a substituent having an aromatic ring or a carbon-carbon double bond, and the like.
  • fluorinated vinylene carbonate derivatives 4-fluorovinylene carbonate, 4-fluoro-5-methylvinylene carbonate, 4-fluoro-5-phenylvinylene carbonate, 4-allyl-5-fluorovinylene carbonate, 4-fluoro-5- And vinyl vinylene carbonate and the like.
  • fluorinated ethylene carbonate derivative substituted by a substituent having an aromatic ring or a carbon-carbon double bond 4-fluoro-4-vinyl ethylene carbonate, 4-fluoro-4-allyl ethylene carbonate, 4-fluoro-5 -Vinyl ethylene carbonate, 4-fluoro-5-allyl ethylene carbonate, 4,4-difluoro-4-vinyl ethylene carbonate, 4,4-difluoro-4-allyl ethylene carbonate, 4,5-difluoro-4-vinyl ethylene carbonate 4,5-Difluoro-4-allyl ethylene carbonate, 4-fluoro-4,5-divinyl ethylene carbonate, 4-fluoro-4,5-diallyl ethylene carbonate, 4,5-difluoro-4,5-divinyl ethylene carbonate , 4,5-Diful 4- 4, 5-diallyl ethylene carbonate, 4-fluoro 4-phenyl ethylene carbonate, 4- fluoro 5- phenyl ethylene carbonate, 4, 4-fluor
  • the molecular weight of the fluorinated unsaturated cyclic carbonate is not particularly limited and is arbitrary unless the effects of the present invention are significantly impaired.
  • the molecular weight is preferably 50 or more and 500 or less. Within this range, it is easy to ensure the solubility of the fluorinated unsaturated cyclic carbonate in the electrolytic solution.
  • the method for producing the fluorinated unsaturated cyclic carbonate is not particularly limited, and any known method can be selected for production.
  • the molecular weight is more preferably 100 or more, and more preferably 200 or less.
  • the fluorinated unsaturated cyclic carbonates may be used alone or in any combination of two or more in any proportion. Further, the content of the fluorinated unsaturated cyclic carbonate is not particularly limited, and is optional unless the effects of the present invention are significantly impaired.
  • the content of the fluorinated unsaturated cyclic carbonate is usually preferably 0.001% by mass or more, more preferably 0.01% by mass or more, and still more preferably 0.1% by mass or more in 100% by mass of the electrolytic solution. Moreover, preferably it is 5 mass% or less, More preferably, it is 4 mass% or less, More preferably, it is 3 mass% or less. Within this range, an electrochemical device using an electrolytic solution is likely to exhibit a sufficient cycle characteristics improvement effect, and also the high temperature storage characteristics deteriorate, the gas generation amount increases, and the discharge capacity retention rate decreases. It is easy to avoid such situations.
  • the electrolytic solution of the present invention may contain a compound having a triple bond.
  • the type is not particularly limited as long as it is a compound having one or more triple bonds in the molecule.
  • Specific examples of the compound having a triple bond include, for example, the following compounds.
  • compounds having an alkynyloxy group are preferable because they form a negative electrode film more stably in the electrolytic solution.
  • 2- Compounds such as propynyl, di-2-propynyl oxalate and the like are particularly preferable from the viewpoint of improving the storage characteristics.
  • the compounds having a triple bond may be used alone or in any combination of two or more in any proportion.
  • the compounding amount of the compound having a triple bond with respect to the entire electrolytic solution of the present invention is not limited, and is optional unless the effects of the present invention are significantly impaired, but generally 0.01% by mass or more with respect to the electrolytic solution of the present invention Preferably, it is contained at a concentration of 0.05% by mass or more, more preferably 0.1% by mass or more, and usually 5% by mass or less, preferably 3% by mass or less, more preferably 1% by mass or less.
  • effects such as output characteristics, load characteristics, cycle characteristics, high temperature storage characteristics and the like are further improved.
  • an overcharge preventing agent can be used to effectively suppress the battery from bursting / ignition when the electrochemical device using the electrolytic solution becomes overcharged or the like.
  • a non-substituted or alkyl-substituted terphenyl derivative such as biphenyl, o-terphenyl, m-terphenyl, p-terphenyl, etc.
  • a non-substituted or alkyl-substituted terphenyl derivative Partial hydrides of cyclohexylbenzene, t-butylbenzene, t-amylbenzene, diphenylether, dibenzofuran, diphenylcyclohexane, 1,1,3-trimethyl-3-phenylindane, cyclopentylbenzene, cyclohexylbenzene, cumene, 1,3- Aromatic compounds such as diisopropylbenzene, 1,4-diisopropylbenzene, t-butylbenzene, t-amylbenzene, t-hexylbenzene, ani
  • aromatic compounds such as biphenyl, alkylbiphenyl, terphenyl, partially hydrogenated terphenyl, cyclohexylbenzene, t-butylbenzene, t-amylbenzene, diphenylether, dibenzofuran, etc., diphenylcyclohexane, 1,1,3-trimethyl -3-phenylindane, 3-propylphenylacetate, 2-ethylphenylacetate, benzylphenylacetate, methylphenylacetate, benzylacetate, diphenyl carbonate, methylphenyl carbonate and the like are preferable. These may be used alone or in combination of two or more.
  • a combination of cyclohexylbenzene and t-butylbenzene or t-amylbenzene biphenyl, alkylbiphenyl, terphenyl, a partially hydrogenated terphenyl, cyclohexylbenzene, t-butylbenzene,
  • the combined use of at least one selected from oxygen-free aromatic compounds such as t-amyl benzene and at least one selected from oxygen-containing aromatic compounds such as diphenyl ether and dibenzofuran is an overcharge preventing property and high temperature storage characteristics It is preferable from the point of balance of
  • a carboxylic acid anhydride (except for the compound (2)) may be used in the electrolytic solution used in the present invention.
  • the compound represented by following General formula (6) is preferable.
  • the method for producing the carboxylic acid anhydride is not particularly limited, and any known method can be selected for production.
  • each of R 61 and R 62 independently represents a hydrocarbon group having 1 to 15 carbon atoms which may have a substituent.
  • R 61 and R 62 is not particularly limited as long as it is a monovalent hydrocarbon group.
  • it may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, or it may be a combination of an aliphatic hydrocarbon group and an aromatic hydrocarbon group.
  • the aliphatic hydrocarbon group may be a saturated hydrocarbon group and may contain an unsaturated bond (carbon-carbon double bond or carbon-carbon triple bond).
  • the aliphatic hydrocarbon group may be linear or cyclic, and in the case of linear, it may be linear or branched. Furthermore, the chain and cyclic groups may be combined.
  • R 61 and R 62 may be identical to or different from each other.
  • the type of the substituent is not particularly limited unless it is contrary to the spirit of the present invention, and examples thereof include a fluorine atom, a chlorine atom and a bromine atom And a halogen atom such as iodine atom, preferably a fluorine atom.
  • a substituent other than a rogen atom a substituent having a functional group such as an ester group, a cyano group, a carbonyl group, an ether group and the like can be mentioned, with preference given to a cyano group and a carbonyl group.
  • the hydrocarbon group of R 61 and R 62 may have only one of these substituents, or may have two or more of these substituents. When they have two or more substituents, those substituents may be the same or may be different from each other.
  • the carbon number of each of the hydrocarbon groups of R 61 and R 62 is usually 1 or more, and usually 15 or less, preferably 12 or less, more preferably 10 or less, still more preferably 9 or less.
  • the carbon number of the bivalent hydrocarbon group is usually 1 or more, and usually 15 or less, preferably It is 13 or less, more preferably 10 or less, still more preferably 8 or less.
  • the hydrocarbon group of R 61 and R 62 has a substituent containing a carbon atom, it is preferable that the total number of carbon atoms of R 61 and R 62 including the substituent satisfy the above range.
  • analog refers to an acid anhydride obtained by replacing a part of the structure of the exemplified acid anhydride with another structure without departing from the spirit of the present invention.
  • Specific examples of the acid anhydride in which R 61 and R 62 are a linear alkyl group include acetic anhydride, propionic anhydride, butanoic acid anhydride, 2-methylpropionic acid anhydride, and 2,2-dimethylpropionic acid anhydride , 2-methylbutanoic anhydride, 3-methylbutanoic anhydride, 2,2-dimethylbutanoic anhydride, 2,3-dimethylbutanoic anhydride, 3,3-dimethylbutanoic anhydride, 2,2, 3-trimethylbutanoic acid anhydride, 2,3,3-trimethylbutanoic acid anhydride, 2,2,3,3-tetramethylbutanoic acid anhydride, 2-ethylbutanoic acid anhydride, etc., and analogs thereof It can be mentioned.
  • R 61 and R 62 are cyclic alkyl groups
  • R 61 and R 62 are cyclic alkyl groups
  • acid anhydrides wherein R 61 and R 62 are cyclic alkyl groups include cyclopropane carboxylic acid anhydride, cyclopentane carboxylic acid anhydride, cyclohexane carboxylic acid anhydride, etc., and analogs thereof, etc. .
  • R 61 and R 62 are an alkenyl group
  • acrylic acid anhydride 2-methyl acrylic acid anhydride, 3-methyl acrylic acid anhydride, 2,3-dimethyl acrylic acid anhydride, 3,3-Dimethylacrylic anhydride, 2,3,3-trimethylacrylic anhydride, 2-phenylacrylic anhydride, 3-phenylacrylic anhydride, 2,3-diphenylacrylic anhydride, 3, 3-diphenylacrylic anhydride, 3-butenoic anhydride, 2-methyl-3-butenoic anhydride, 2,2-dimethyl-3-butenoic anhydride, 3-methyl-3-tenoic anhydride, 2-Methyl-3-methyl-3-butenoic anhydride, 2,2-dimethyl-3-methyl-3-butenoic anhydride, 3-pentenoic anhydride, 4-pentenoic anhydride, 2-cyclopentene carboxylic acid Acid anhydride , 3-cyclopentene carboxylic acid anhydride,
  • R 61 and R 62 are an alkynyl group
  • Specific examples of the acid anhydride wherein R 61 and R 62 are an alkynyl group include propynic acid anhydride, 3-phenylpropynic acid anhydride, 2-butyric acid anhydride, 2-pentynic acid anhydride, 3-butyric acid Anhydrides, 3-pentynic acid anhydride, 4-pentynic acid anhydride and the like, and analogs thereof and the like can be mentioned.
  • R 61 and R 62 are aryl groups
  • benzoic acid anhydride 4-methylbenzoic acid anhydride, 4-ethylbenzoic acid anhydride, 4-tert-butylbenzoic acid anhydride
  • examples thereof include 2-methylbenzoic acid anhydride, 2,4,6-trimethylbenzoic acid anhydride, 1-naphthalenecarboxylic acid anhydride, 2-naphthalenecarboxylic acid anhydride and the like, and analogs thereof.
  • R 61, R 62 are substituted with halogen atoms
  • halogen atoms mainly cited example has been anhydride substituted with a fluorine atom are set forth below, some or all of these fluorine atoms
  • An acid anhydride obtained by substitution to a chlorine atom, a bromine atom or an iodine atom is also included in the exemplified compounds.
  • Examples of acid anhydrides in which R 61 and R 62 are a linear alkyl group substituted with a halogen atom include fluoroacetic acid anhydride, difluoroacetic acid anhydride, trifluoroacetic acid anhydride, 2-fluoropropionic acid anhydride, 2,2-difluoropropionic anhydride, 2,3-difluoropropionic anhydride, 2,2,3-trifluoropropionic anhydride, 2,3,3-trifluoropropionic anhydride, 2,2,3, 3,3-tetrapropionic anhydride, 2,3,3,3-tetrapropionic anhydride, 3-fluoropropionic anhydride, 3,3-difluoropropionic anhydride, 3,3,3-trifluoro Examples thereof include propionic acid anhydride, perfluoropropionic acid anhydride, and the like, and analogs thereof.
  • 2-fluorocyclopentanecarboxylic acid anhydride 3-fluorocyclopentanecarboxylic acid anhydride, 4-fluorocyclopentane as an example of the acid anhydride which is a cyclic alkyl group in which R 61 and R 62 are substituted by a halogen atom Examples thereof include carboxylic acid anhydrides and the like and analogs thereof.
  • Examples of the acid anhydride which is an alkenyl group in which R 61 and R 62 are substituted by a halogen atom include 2-fluoroacrylic anhydride, 3-fluoroacrylic anhydride, 2,3-difluoroacrylic anhydride, 3,3-Difluoroacrylic anhydride, 2,3,3-trifluoroacrylic anhydride, 2- (trifluoromethyl) acrylic anhydride, 3- (trifluoromethyl) acrylic anhydride, 2,3 -Bis (trifluoromethyl) acrylic anhydride, 2,3,3-tris (trifluoromethyl) acrylic anhydride, 2- (4-fluorophenyl) acrylic anhydride, 3- (4-fluorophenyl) Acrylic anhydride, 2,3-bis (4-fluorophenyl) acrylic anhydride, 3,3-bis (4-fluorophenyl) acrylic anhydride, 2-fluoro 3-butenoic anhydride, 2,2-difluoro-3-butenoic anhydr
  • the acid anhydride which is an alkynyl group in which R 61 and R 62 are substituted by a halogen atom
  • 3-fluoro-2-propanoic acid anhydride 3- (4-fluorophenyl) -2-propynic acid anhydride
  • 3- (2,3,4,5,6-pentafluorophenyl) -2-propanoic acid anhydride 4-fluoro-2-butyric acid anhydride, 4,4-difluoro-2-butyric acid anhydride, And 4,4,4-trifluoro-2-butyric anhydride and the like, and analogs thereof.
  • Examples of the acid anhydride which is an aryl group in which R 61 and R 62 are substituted by a halogen atom include 4-fluorobenzoic acid anhydride, 2,3,4,5,6-pentafluorobenzoic acid anhydride, 4 And-trifluoromethylbenzoic anhydride and the like, and analogs thereof and the like.
  • Examples of the acid anhydride having a substituent having a functional group such as ester, nitrile, ketone or ether as R 61 and R 62 are methoxyformic anhydride, ethoxyformic anhydride, methyl oxalic acid anhydride, Ethyl oxalic acid anhydride, 2-cyanoacetic acid anhydride, 2-oxopropionic acid anhydride, 3-oxobutanoic acid anhydride, 4-acetylbenzoic acid anhydride, methoxyacetic acid anhydride, 4-methoxybenzoic acid anhydride, etc. And their analogs.
  • Examples of combinations of linear alkyl groups include acetic propionic acid anhydride, acetic acid butanoic acid anhydride, butanoic acid propionic acid anhydride, acetic acid 2-methyl propionic acid anhydride, and the like.
  • Examples of the combination of a linear alkyl group and a cyclic alkyl group include acetic acid cyclopentanic acid anhydride, acetic acid cyclohexanic acid anhydride, cyclopentanic acid propionic acid anhydride, and the like.
  • Examples of the combination of a linear alkyl group and an alkenyl group include acetic acid acrylic anhydride, acetic acid 3-methylacrylic acid anhydride, acetic acid 3-butenoic acid anhydride, acrylic acid propionic acid anhydride, and the like.
  • Examples of the combination of a linear alkyl group and an alkynyl group are: acetic anhydride propynic acid anhydride, acetic acid 2-butyric acid anhydride, acetic acid 3-butyric acid anhydride, acetic acid 3-phenylpropynic acid propionic acid propionic acid anhydride , Etc.
  • Examples of the combination of a linear alkyl group and an aryl group include acetic acid benzoic acid anhydride, acetic acid 4-methylbenzoic acid anhydride, acetic acid 1-naphthalenecarboxylic acid anhydride, benzoic acid propionic acid anhydride, and the like.
  • Examples of the combination of a linear alkyl group and a hydrocarbon group having a functional group are: acetic anhydride, acetic anhydride, trifluoroacetic anhydride, acetic anhydride, 4-fluorobenzoic anhydride, fluoroacetic propionic anhydride, alkyl acetate Examples thereof include oxalic acid anhydride, acetic acid 2-cyanoacetic acid anhydride, acetic acid 2-oxopropionic acid anhydride, acetic acid methoxyacetic acid anhydride, methoxyacetic acid propionic acid anhydride and the like.
  • Examples of combinations of cyclic alkyl groups include cyclopentanoic acid cyclohexane anhydride and the like.
  • Examples of the combination of a cyclic alkyl group and an alkenyl group include acrylic acid cyclopentanic acid anhydride, 3-methylacrylic acid cyclopentanic acid anhydride, 3-butenoic acid cyclopentanic acid anhydride, acrylic acid cyclohexaneic acid anhydride, etc. Can be mentioned.
  • Examples of the combination of a cyclic alkyl group and an alkynyl group include propynoic acid cyclopentanic acid anhydride, 2-butyric acid cyclopentanic acid anhydride, propynoic acid cyclohexane acid anhydride, and the like.
  • Examples of the combination of a cyclic alkyl group and an aryl group include benzoic acid cyclopentanic acid anhydride, 4-methylbenzoic acid cyclopentanic acid anhydride, benzoic acid cyclohexanic acid anhydride, and the like.
  • Examples of combinations of cyclic alkyl groups and hydrocarbon groups having a functional group include fluoroacetic acid cyclopentanic acid anhydride, cyclopentanic acid trifluoroacetic acid anhydride, cyclopentanic acid 2-cyanoacetic acid anhydride, cyclopentanic acid methoxyacetic acid Anhydrides, cyclohexane acid fluoroacetic acid anhydride, etc. are mentioned.
  • alkenyl groups acrylic acid 2-methylacrylic anhydride, acrylic acid 3-methylacrylic anhydride, acrylic acid 3-butenoic anhydride, 2-methylacrylic acid 3-methylacrylic anhydride Things, etc.
  • Examples of the combination of the alkenyl group and the alkynyl group include acrylic acid propynic acid anhydride, acrylic acid 2-butyric acid anhydride, 2-methyl acrylic acid propynic acid anhydride and the like.
  • Examples of the combination of the alkenyl group and the aryl group include acrylic acid benzoic acid anhydride, acrylic acid 4-methylbenzoic acid anhydride, 2-methyl acrylic acid benzoic acid anhydride, and the like.
  • alkenyl group and hydrocarbon group having a functional group examples include acrylic acid fluoroacetic acid anhydride, acrylic acid trifluoroacetic acid anhydride, acrylic acid 2-cyanoacetic acid anhydride, acrylic acid methoxyacetic acid anhydride, 2- Methyl acrylic acid fluoro acetic acid anhydride etc. are mentioned.
  • Examples of combinations of alkynyl groups include propyric acid 2-butyric acid anhydride, propyric acid 3-butyric acid anhydride, 2-butyric acid 3-butyric acid anhydride, and the like.
  • Examples of the combination of an alkynyl group and an aryl group include propyric anhydride benzoic acid, propyric anhydride 4-methylbenzoic acid, 2-butyric anhydride benzoic acid, and the like.
  • Examples of the combination of an alkynyl group and a hydrocarbon group having a functional group include propynoic acid fluoroacetic acid anhydride, propynoic acid trifluoroacetic acid anhydride, propynoic acid 2-cyanoacetic acid anhydride, propymic acid methoxyacetic acid anhydride, 2- Butyric acid fluoroacetic acid anhydride and the like can be mentioned.
  • Examples of combinations of aryl groups include benzoic acid 4-methylbenzoic acid anhydride, benzoic acid 1-naphthalenecarboxylic acid anhydride, 4-methylbenzoic acid 1-naphthalenecarboxylic acid anhydride, and the like.
  • Examples of the combination of an aryl group and a hydrocarbon group having a functional group include benzoic acid fluoroacetic acid anhydride, benzoic acid trifluoroacetic acid anhydride, benzoic acid 2-cyanoacetic acid anhydride, benzoic acid methoxyacetic acid anhydride, 4- Methylbenzoic acid fluoroacetic acid anhydride and the like can be mentioned.
  • hydrocarbon groups having a functional group examples include fluoroacetic acid trifluoroacetic acid anhydride, fluoroacetic acid 2-cyanoacetic acid anhydride, fluoroacetic acid methoxyacetic acid anhydride, trifluoroacetic acid 2-cyanoacetic acid anhydride, etc. Can be mentioned.
  • acetic anhydride preferred are acetic anhydride, propionic acid anhydride, 2-methylpropionic acid anhydride, cyclopentanecarboxylic acid anhydride, cyclohexane carboxylic acid anhydride, etc., acrylic acid Anhydride, 2-methylacrylic anhydride, 3-methylacrylic anhydride, 2,3-dimethylacrylic anhydride, 3, 3-dimethylacrylic anhydride, 3-butenoic anhydride, 2-methyl- 3-butenoic acid anhydride, propynic acid anhydride, 2-butyric acid anhydride, benzoic acid anhydride, 2-methylbenzoic acid anhydride, 4-methylbenzoic acid anhydride, 4-tert-butylbenzoic acid anhydride, Trifluoroacetic acid anhydride, 3,3,3-trifluoropropionic acid anhydride, 2- (trifluoromethyl) acrylic acid anhydride, 2- (4-fluorophenyl) acrylic acid Water
  • These compounds can improve the charge / discharge rate characteristics, the input / output characteristics, and the impedance characteristics after the durability test, in particular, by forming a bond with a lithium oxalate salt appropriately to form a film excellent in durability. It is preferable from the viewpoint of
  • the molecular weight of the carboxylic acid anhydride is not limited as long as the effects of the present invention are not significantly impaired, but is usually 90 or more, preferably 95 or more, and 300 or less, preferably 200 or less. is there.
  • the molecular weight of the carboxylic acid anhydride is in the above range, the increase in viscosity of the electrolytic solution can be suppressed, and the film density can be optimized, so that the durability can be appropriately improved.
  • the carboxylic acid anhydride described above may contain any one type alone in the non-aqueous electrolyte solution of the present invention, or two or more types in any combination and ratio.
  • the content of the above-mentioned carboxylic anhydride with respect to the electrolytic solution of the present invention is optional as long as the effects of the present invention are not significantly impaired. It is desirable to contain at a concentration of% or more, preferably 0.1% by mass or more, and usually 5% by mass or less, preferably 3% by mass or less.
  • the content of the carboxylic acid anhydride is in the above range, the effect of improving the cycle characteristics is easily exhibited, and since the reactivity is suitable, the battery characteristics are easily improved.
  • auxiliary agents can be used in the electrolytic solution of the present invention.
  • Other auxiliary agents include carbonate compounds such as erythritan carbonate, spiro-bis-dimethylene carbonate, methoxyethyl-methyl carbonate and the like; 2,4,8,10-tetraoxaspiro [5.5] undecane, 3,9 Spiro compounds such as divinyl-2,4,8,10-tetraoxaspiro [5.5] undecane; ethylene sulfite, methyl fluorosulfonate, ethyl fluorosulfonate, methyl methanesulfonate, ethyl methanesulfonate, busulfan , Sulfolene, ethylene sulfate, vinylene sulfate, diphenyl sulfone, N, N-dimethyl methane sulfonamide, N, N-diethyl methane sulfonamide, acetamide, N-
  • phosphorus-containing compounds are preferable, and tris (trimethylsilyl) phosphate is preferable.
  • the amount of the other auxiliary agent is not particularly limited, and is optional unless the effects of the present invention are significantly impaired.
  • the other auxiliary agent is preferably 0.01% by mass or more and 5% by mass or less in 100% by mass of the electrolytic solution. Within this range, the effects of the other auxiliary agents can be sufficiently exhibited, and situations in which battery characteristics such as high load discharge characteristics are degraded can be easily avoided.
  • the compounding amount of the other auxiliary agent is more preferably 0.1% by mass or more, still more preferably 0.2% by mass or more, and more preferably 3% by mass or less, still more preferably 1% by mass or less .
  • the electrolytic solution of the present invention is a cyclic and linear carboxylic acid ester, an ether compound, a nitrogen-containing compound, a boron-containing compound, an organic silicon-containing compound, an incombustible (flame retardant) agent, an interface, as long as the effects of the present invention are not impaired.
  • Activators, high dielectric additives, cycle characteristics and rate characteristics improvers, sulfone compounds and the like may further be contained as additives.
  • Examples of the cyclic carboxylic acid ester include those having 3 to 12 carbon atoms in total in the structural formula. Specific examples thereof include gamma-butyrolactone, gamma-valerolactone, gamma-caprolactone, epsilon-caprolactone, 3-methyl- ⁇ -butyrolactone and the like. Among them, gamma-butyrolactone is particularly preferable from the viewpoint of the improvement of the characteristics of the electrochemical device derived from the improvement of the lithium ion dissociation degree.
  • the compounding amount of the cyclic carboxylic acid ester as the additive is usually 0.1% by mass or more, preferably 1% by mass or more, in 100% by mass of the solvent. Within this range, the electrical conductivity of the electrolytic solution can be improved, and the large current discharge characteristics of the electrochemical device can be easily improved. Moreover, the compounding quantity of cyclic carboxylic acid ester becomes like this. Preferably it is 10 mass% or less, More preferably, it is 5 mass% or less. By setting the upper limit in this way, the viscosity of the electrolytic solution is made into an appropriate range, the decrease of the electric conductivity is avoided, the increase of the negative electrode resistance is suppressed, and the large current discharge characteristics of the electrochemical device is made into a good range. Make it easy.
  • fluorinated cyclic carboxylic acid ester (fluorine-containing lactone) can also be used suitably.
  • fluorine-containing lactone for example, the following formula (C):
  • X 15 to X 20 are the same or different, and each is —H, —F, —Cl, —CH 3 or a fluorinated alkyl group; provided that at least one of X 15 to X 20 is a fluorinated alkyl group Is the group)
  • fluorine-containing lactones represented by
  • fluorinated alkyl group in X 15 to X 20 for example, -CFH 2 , -CF 2 H, -CF 3 , -CH 2 CF 3 , -CF 2 CF 3 , -CH 2 CF 2 CF 3 , -CF (CF 3 ) 2 and the like, and from the viewpoint of high oxidation resistance and safety improving effect, —CH 2 CF 3 and —CH 2 CF 2 CF 3 are preferable.
  • X 15 to X 20 is a fluorinated alkyl group
  • -H, -F, -Cl, -CH 3 or a fluorinated alkyl group is substituted at only one position of X 15 to X 20 and It may be replaced with a plurality of places.
  • it is preferably one to three, and more preferably one to two.
  • X 17 and / or X 18 is, in particular X 17 or X 18 is a fluorinated alkyl group, inter alia -CH 2 CF 3 And —CH 2 CF 2 CF 3 is preferable.
  • X 15 to X 20 other than the fluorinated alkyl group are —H, —F, —Cl or CH 3 , and in particular, —H is preferable from the viewpoint of good solubility of the electrolyte salt.
  • a and B each represent one of CX 226 X 227 (wherein X 226 and X 227 are the same or different, and each represents -H, -F, -Cl, -CF 3 , -CH 3 or a hydrogen atom
  • R f 12 is a fluorinated alkyl group which may have an ether bond or fluorinated Alkoxy groups
  • X 221 and X 222 are the same or different, and all are -H, -F, -Cl, -CF 3 or CH 3
  • X 223 to X 225 are the same or different, all are -H, -F , -Cl or an alkyl group whose hydrogen atom may be substituted with a halogen atom and may contain a hetero atom in the chain;
  • n 0 or 1
  • the five-membered ring structure represented by is preferably exemplified from the viewpoint of easy synthesis and good chemical stability, and further, by the combination of A and B, the following formula (F):
  • linear carboxylic acid ester examples include those having 3 to 7 carbon atoms in total in the structural formula. Specifically, methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, t-butyl acetate, methyl propionate, ethyl propionate, n-propyl propionate, Isobutyl propionate, n-butyl propionate, methyl butyrate, isobutyl propionate, t-butyl propionate, methyl butyrate, ethyl butyrate, n-propyl butyrate, isopropyl butyrate, methyl isobutyrate, ethyl isobutyrate, isobutyrate Butyric acid-n-propyl, isopropyl isobutyrate and the like can be mentioned.
  • the ether compound is preferably a C2-C10 linear ether and a C3-C6 cyclic ether.
  • the linear ether having 2 to 10 carbons includes dimethyl ether, diethyl ether, di-n-butyl ether, dimethoxymethane, methoxyethoxymethane, diethoxymethane, dimethoxyethane, methoxyethoxyethane, diethoxyethane, ethylene glycol di-n And -propyl ether, ethylene glycol di-n-butyl ether, diethylene glycol, diethylene glycol dimethyl ether, pentaethylene glycol, triethylene glycol dimethyl ether, triethylene glycol, tetraethylene glycol, tetraethylene glycol dimethyl ether, diisopropyl ether and the like.
  • a fluorinated ether can also be used suitably.
  • fluorinated ether the following general formula (I): Rf 3 -O-Rf 4 (I) (Wherein, R f 3 and R f 4 are the same or different and are an alkyl group of 1 to 10 carbon atoms or a fluorinated alkyl group of 1 to 10 carbon atoms, provided that at least one of R f 3 and R f 4 is fluorine Alkylated groups)
  • fluorinated ethers (I) represented by By containing the fluorinated ether (I), the flame retardancy of the electrolytic solution is improved, and the stability at high temperature and high voltage and the safety are improved.
  • At least one of Rf 3 and Rf 4 may be a fluorinated alkyl group having 1 to 10 carbon atoms, but the flame retardancy of the electrolytic solution, stability at high temperature and high voltage, safety From the viewpoint of further improving the properties, it is preferable that both Rf 3 and Rf 4 be a fluorinated alkyl group having 1 to 10 carbon atoms. In this case, Rf 3 and Rf 4 may be the same or may be different from each other.
  • Rf 3 and Rf 4 are the same or different, and Rf 3 is a fluorinated alkyl group having 3 to 6 carbon atoms, and Rf 4 is a fluorinated alkyl group having 2 to 6 carbon atoms More preferable.
  • the fluorinated ether (I) preferably has a fluorine content of 40 to 75% by mass. When it has a fluorine content in this range, the balance between incombustibility and compatibility becomes particularly excellent. Moreover, it is preferable also from the point whose oxidation resistance and safety are favorable.
  • the lower limit of the fluorine content is more preferably 45% by mass, further preferably 50% by mass, and particularly preferably 55% by mass.
  • the upper limit is more preferably 70% by mass, and still more preferably 66% by mass.
  • the fluorine content of the fluorinated ether (I) is ⁇ (number of fluorine atoms ⁇ 19) / molecular weight of fluorinated ether (I) ⁇ ⁇ 100 (%) based on the structural formula of fluorinated ether (I) It is a value calculated by
  • the Rf 3 for example, CF 3 CF 2 CH 2 - , CF 3 CFHCF 2 -, HCF 2 CF 2 CF 2 -, HCF 2 CF 2 CH 2 -, CF 3 CF 2 CH 2 CH 2 -, CF 3 CFHCF 2 CH 2- , HCF 2 CF 2 CF 2 CF 2- , HCF 2 CF 2 CH 2- , HCF 2 CF (CF 3 ) CH 2- and the like.
  • Rf 4 for example, -CH 2 CF 2 CF 3, -CF 2 CFHCF 3, -CF 2 CF 2 CF 2 H, -CH 2 CF 2 CF 2 H, -CH 2 CH 2 CF 2 CF 3 , -CH 2 CF 2 CFHCF 3 , -CF 2 CF 2 CF 2 CF 2 H, -CH 2 CF 2 CF 2 H, -CH 2 CH 2 CF 2 CF 2 H, -CH 2 CF (CF 3 )
  • Examples include CF 2 H, -CF 2 CF 2 H, -CH 2 CF 2 H, -CF 2 CH 3 and the like.
  • fluorinated ether (I) for example HCF 2 CF 2 CH 2 OCF 2 CF 2 H, CF 3 CF 2 CH 2 OCF 2 CF 2 H, HCF 2 CF 2 CH 2 OCF 2 CFHCF 3, CF 3 CF 2 CH 2 OCF 2 CFHCF 3 , C 6 F 13 OCH 3 , C 6 F 13 OC 2 H 5 , C 8 F 17 OCH 3 , C 8 F 17 OC 2 H 5 , CF 3 CFHCF 2 CH (CH 3 ) OCF 2 CFHCF 3 , HCF 2 CF 2 OCH (C 2 H 5 ) 2 , HCF 2 CF 2 OC 4 H 9 , HCF 2 CF 2 OCH 2 CH (C 2 H 5 ) 2 , HCF 2 CF 2 OCH 2 CH (CH 3 ) 2 and the like.
  • fluorinated ether (I) having a high boiling point can be provided.
  • the boiling point of the fluorinated ether (I) is preferably 67 to 120 ° C.
  • the temperature is more preferably 80 ° C. or more, still more preferably 90 ° C. or more.
  • HCF 2 CF 2 CH 2 OCF 2 CFHCF 3 (boiling point 106 ° C.), CF 3 CF 2 CH, which is advantageous in that it has high boiling point, compatibility with other solvents and good solubility of electrolyte salt.
  • Examples of cyclic ethers having 3 to 6 carbon atoms include 1,2-dioxane, 1,3-dioxane, 2-methyl-1,3-dioxane, 4-methyl-1,3-dioxane, 1,4-dioxane, and meta.
  • dimethoxymethane, diethoxymethane, ethoxymethoxymethane, ethylene glycol-n-propyl ether, ethylene glycol di-n-butyl ether, diethylene glycol dimethyl ether, and crown ether have high ability to solvate lithium ion, and the degree of ion dissociation Preferred from the viewpoint of improvement, and particularly preferred are dimethoxymethane, diethoxymethane and ethoxymethoxymethane because they have low viscosity and give high ion conductivity.
  • nitrogen-containing compound examples include nitriles, fluorine-containing nitriles, carboxylic acid amides, fluorine-containing carboxylic acid amides, sulfonic acid amides, fluorine-containing sulfonic acid amides, acetamide, formamide and the like.
  • 1-methyl-2-pyrrolidinone, 1-methyl-2-piperidone, 3-methyl-2-oxaziridinone, 1,3-dimethyl-2-imidazolidinone and N-methylsuccinimide can also be used.
  • the nitrile compounds represented by the above general formulas (1a), (1b) and (1c) are not included in the above nitrogen-containing compound.
  • boron-containing compound examples include borate esters such as trimethyl borate and triethyl borate, borate ethers, and alkyl borates.
  • organic silicon-containing compound examples include (CH 3 ) 4 -Si, (CH 3 ) 3 -Si-Si (CH 3 ) 3 , silicone oil and the like.
  • non-combustible (flame-retardant) agent examples include phosphoric acid esters and phosphazene compounds.
  • phosphoric acid ester examples include fluorine-containing alkyl phosphoric acid esters, non-fluorinated alkyl phosphoric acid esters, and aryl phosphoric acid esters. Among them, fluorine-containing alkyl phosphates are preferable in that they can exhibit the non-combustible effect in a small amount.
  • Examples of the phosphazene-based compounds include methoxypentafluorocyclotriphosphazene, phenoxypentafluorocyclotriphosphazene, dimethylaminopentafluorocyclotriphosphazene, diethylaminopentafluorocyclotriphosphazene, ethoxypentafluorocyclotriphosphazene, and ethoxyheptafluorocyclotetraphosphazene. Can be mentioned.
  • fluorine-containing alkyl phosphoric acid ester examples include fluorine-containing dialkyl phosphoric acid esters described in JP-A-11-233141, and cyclic alkyl phosphoric acid esters described in JP-A-11-283669. And / or fluorine-containing trialkyl phosphate esters and the like.
  • the surfactant may be any of a cationic surfactant, an anionic surfactant, a nonionic surfactant, and an amphoteric surfactant, but from the viewpoint of favorable cycle characteristics and rate characteristics, a fluorine atom. Is preferable.
  • Examples of such a surfactant containing a fluorine atom include the following formula (30): Rf 5 COO - M + (30) (Wherein R f 5 is a fluorine-containing alkyl group which may contain an ether bond of 3 to 10 carbon atoms; M + is Li + , Na + , K + or NHR ′ 3 + (R ′ is the same or different) , All are H or an alkyl group having 1 to 3 carbon atoms)) Or a fluorinated carboxylic acid salt represented by the following formula (40): Rf 6 SO 3 - M + (40) (Wherein, Rf 6 is a fluorine-containing alkyl group which may contain an ether bond of 3 to 10 carbon atoms; M + is Li + , Na + , K + or NHR ′ 3 + (R ′ is the same or different) , All are H or an alkyl group having 1 to 3 carbon atoms))
  • the content of the surfactant is preferably 0.01 to 2% by mass in the electrolytic solution, from the viewpoint of being able to reduce the surface tension of the electrolytic solution without deteriorating the charge-discharge cycle characteristics.
  • high dielectric additives examples include sulfolane, methylsulfolane, ⁇ -butyrolactone, ⁇ -valerolactone and the like.
  • cycle characteristics and rate characteristics improver examples include methyl acetate, ethyl acetate, tetrahydrofuran, 1,4-dioxane and the like.
  • electrolytic solution of the present invention may be further combined with a polymer material to form a gel (plasticized) gel electrolytic solution.
  • polymer materials conventionally known polyethylene oxide and polypropylene oxide, modified products thereof (Japanese Patent Laid-Open Nos. 8-222270 and 2002-100405); polyacrylate polymers, polyacrylonitrile, polyvinylidene fluoride and the like And fluorine resins such as vinylidene fluoride-hexafluoropropylene copolymer (JP-A-4-506726, JP-A-8-507407, JP-A-10-294131); those fluororesins and hydrocarbon-based resins Composites with resins (JP-A-11-35765, JP-A-11-86630) and the like can be mentioned.
  • the electrolytic solution of the present invention may also contain the ion conductive compound described in Japanese Patent Application No. 2004-301934.
  • This ion conductive compound has the formula (1-1): A- (D) -B (1-1) [Wherein, D is the formula (2-1): -(D1) n- (FAE) m- (AE) p- (Y) q- (2-1) (Wherein, D1 is the formula (2a):
  • R f is a fluorine-containing ether group which may have a crosslinkable functional group; R 10 is a group or a bond which connects R f to the main chain
  • An ether unit having a fluorinated ether group in the side chain represented by The FAE is represented by the formula (2b):
  • Rfa is a hydrogen atom, a fluorinated alkyl group which may have a crosslinkable functional group; R 11 is a group or a bond which connects Rfa to the main chain
  • An ether unit having a fluorinated alkyl group in the side chain represented by AE is the equation (2c):
  • R 13 has a hydrogen atom, an alkyl group which may have a crosslinkable functional group, an aliphatic cyclic hydrocarbon group which may have a crosslinkable functional group, or a crosslinkable functional group Aromatic hydrocarbon group which may be substituted; R 12 is a group or a bond which connects R 13 to the main chain)
  • Ether unit indicated by Y is any of the formulas (2d-1) to (2d-3):
  • a and B are the same or different, and are a hydrogen atom, a fluorine atom and / or an alkyl group which may contain a crosslinkable functional group, a fluorine atom and / or a phenyl group which may contain a crosslinkable functional group, -COOH Group, -OR (R is a hydrogen atom or a fluorine atom and / or an alkyl group which may contain a crosslinkable functional group), an ester group or a carbonate group (provided that the terminal of D is an oxygen atom, -COOH group, -OR, not ester group and carbonate group)] It is an a
  • the electrolytic solution of the present invention may contain a sulfone-based compound.
  • a sulfone-based compound a cyclic sulfone having 3 to 6 carbon atoms and a chain sulfone having 2 to 6 carbon atoms are preferable.
  • the number of sulfonyl groups in one molecule is preferably 1 or 2.
  • cyclic sulfones include monosulfone compounds such as trimethylenesulfones, tetramethylenesulfones, hexamethylenesulfones, disulfone compounds such as trimethylenedisulfones, tetramethylenedisulfones, and hexamethylenedisulfones.
  • monosulfone compounds such as trimethylenesulfones, tetramethylenesulfones, hexamethylenesulfones, disulfone compounds such as trimethylenedisulfones, tetramethylenedisulfones, and hexamethylenedisulfones.
  • tetramethylene sulfones, tetramethylene disulfones, hexamethylene sulfones and hexamethylene disulfones are more preferable, and tetramethylene sulfones (sulfolanes) are particularly preferable, from the
  • the sulfolanes are preferably sulfolanes and / or sulfolane derivatives (hereinafter sometimes abbreviated as “sulfolanes” including sulfolanes).
  • sulfolanes sulfolanes
  • the sulfolane derivative one in which at least one hydrogen atom bonded to a carbon atom constituting a sulfolane ring is substituted with a fluorine atom or an alkyl group is preferable.
  • the content of the sulfone-based compound is not particularly limited and is arbitrary unless the effects of the present invention are significantly impaired. However, the content is generally 0.3% by volume or more, preferably 0.5% by volume or more in 100% by volume of the solvent And more preferably 1% by volume or more, and usually 40% by volume or less, preferably 35% by volume or less, and more preferably 30% by volume or less. If the content of the sulfone-based compound is within the above range, the effect of improving the durability such as cycle characteristics and storage characteristics can be easily obtained, and the viscosity of the non-aqueous electrolyte solution can be made into an appropriate range to lower the electrical conductivity. Can be avoided, and the input / output characteristics and charge / discharge rate characteristics of the non-aqueous electrolytic solution secondary battery can be made in an appropriate range.
  • the electrolytic solution of the present disclosure is at least one selected from the group consisting of lithium fluorophosphate salts (with the exception of LiPF 6 ) and lithium salts having an S ⁇ O group as additives from the viewpoint of improving output characteristics. It is also preferable to include the compound (7) of In addition, when using a compound (7) as an additive, it is preferable to use compounds other than a compound (7) as an electrolyte salt mentioned above.
  • lithium fluorophosphate salts examples include lithium monofluorophosphate (LiPO 3 F), lithium difluorophosphate (LiPO 2 F 2 ), and the like.
  • LiPO 2 F 2 , FSO 3 Li and C 2 H 5 OSO 3 Li are preferable as the compound (7).
  • the content of the compound (7) is preferably 0.001 to 20% by mass, more preferably 0.01 to 15% by mass, and further preferably 0.1 to 10% by mass, with respect to the electrolyte solution. It is more preferable that the content be 0.1 to 7% by mass.
  • additives may be added to the electrolytic solution of the present invention as required.
  • examples of other additives include metal oxides and glasses.
  • the content of hydrogen fluoride (HF) in the electrolytic solution of the present invention is preferably 5 to 200 ppm.
  • HF hydrogen fluoride
  • film formation of the above-mentioned additive can be promoted.
  • the content of HF is too low, the film forming ability on the negative electrode tends to be reduced, and the characteristics of the electrochemical device tend to be deteriorated.
  • the HF content is too high, the oxidation resistance of the electrolytic solution tends to decrease due to the influence of HF.
  • the electrolytic solution of the present invention does not lower the high temperature storability recovery capacity rate of the electrochemical device even if it contains HF in the above range.
  • content of HF 10 ppm or more is more preferable, and 20 ppm or more is still more preferable.
  • the content of HF is also preferably 100 ppm or less, more preferably 80 ppm or less, and particularly preferably 50 ppm or less.
  • the content of HF can be measured by neutralization titration.
  • the electrolytic solution of the present invention may be prepared by any method using the components described above.
  • the electrolytic solution of the present invention can be suitably applied to electrochemical devices such as, for example, lithium ion secondary batteries, lithium ion capacitors, hybrid capacitors, and electric double layer capacitors.
  • electrochemical devices such as, for example, lithium ion secondary batteries, lithium ion capacitors, hybrid capacitors, and electric double layer capacitors.
  • a non-aqueous electrolytic solution battery using the electrolytic solution of the present invention will be described.
  • the non-aqueous electrolyte battery can have a known structure, and typically includes a positive electrode and a positive electrode capable of inserting and extracting ions (for example, lithium ions), and the electrolytic solution of the present invention.
  • An electrochemical device comprising such an electrolytic solution of the present invention is also one of the present invention.
  • Electrochemical devices include lithium ion secondary batteries, lithium ion capacitors, capacitors (hybrid capacitors, electric double layer capacitors), radical cells, solar cells (especially dye-sensitized solar cells), lithium ion primary cells, fuel cells, Various electrochemical sensors, electrochromic devices, electrochemical switching devices, aluminum electrolytic capacitors, tantalum electrolytic capacitors and the like can be mentioned, and lithium ion secondary batteries, lithium ion capacitors, electric double layer capacitors are preferable.
  • a module comprising the above-mentioned electrochemical device is also one of the present invention.
  • the present invention is also a lithium ion secondary battery comprising the electrolytic solution of the present invention.
  • the lithium ion secondary battery preferably includes a positive electrode, a negative electrode, and the above-described electrolyte solution.
  • the positive electrode is composed of a positive electrode active material layer containing a positive electrode active material and a current collector.
  • the positive electrode active material is not particularly limited as long as it can electrochemically store and release lithium ions, but, for example, a lithium-containing transition metal complex oxide, a lithium-containing transition metal phosphate compound, a sulfide, a conductive material Polymers and the like.
  • a lithium-containing transition metal complex oxide and a lithium-containing transition metal phosphate compound are preferable, and in particular, a lithium-containing transition metal complex oxide that produces high voltage is preferable.
  • transition metal of the lithium-containing transition metal complex oxide V, Ti, Cr, Mn, Fe, Co, Ni, Cu, etc. are preferable.
  • lithium cobalt complex oxide such as LiCoO 2 , LiNiO 2 etc.
  • Lithium-manganese complex oxides such as LiMnO 2 , LiMn 2 O 4 , Li 2 MnO 4 and the like, and a part of the transition metal atoms as the main component of these lithium transition metal complex oxides, Na, Substitution with other elements such as K, B, F, Al, Ti, V, Cr, Mn, Fe, Co, Li, Ni, Cu, Zn, Mg, Ga, Zr, Si, Nb, Mo, Sn, W, etc.
  • LiNi 0.5 Mn 0.5 O 2, LiNi 0.85 Co 0.10 Al 0.05 O 2, LiNi 0.5 Co 0.2 Mn 0.3 O 2, LiNi 0.6 Co 0.2 Mn 0.2 O 2, LiNi 0.33 Co 0.33 Mn 0.33 O 2, LiNi 0.45 Co 0.10 Al 0.45 O 2, LiMn 1. 8 Al 0.2 O 4 , LiMn 1.5 Ni 0.5 O 4 and the like can be mentioned.
  • lithium-containing transition metal complex oxide LiMn 1.5 Ni 0.5 O 4 , LiNi 0.5 Co 0.2 Mn 0.3 O 2 , which have high energy density even at high voltage. LiNi 0.6 Co 0.2 Mn 0.2 O 2 is preferred.
  • transition metal of the lithium-containing transition metal phosphate compound V, Ti, Cr, Mn, Fe, Co, Ni, Cu and the like are preferable, and as a specific example, for example, LiFePO 4 , Li 3 Fe 2 (PO 4 ) 3 , iron phosphates such as LiFeP 2 O 7 , cobalt phosphates such as LiCoPO 4 , and a part of transition metal atoms which become main components of these lithium transition metal phosphate compounds Al, Ti, V, Cr, Mn What is substituted by other elements, such as Fe, Co, Li, Ni, Cu, Zn, Mg, Ga, Zr, Nb, Si, etc. are mentioned.
  • lithium-containing transition metal composite oxide examples include Formula: Li a Mn 2-b M 1 b O 4 (wherein, 0.9 ⁇ a; 0 ⁇ b ⁇ 1.5; M 1 is Fe, Co, Ni, Cu, Zn, Al, Sn, Cr, Lithium-manganese spinel composite oxide represented by at least one metal selected from the group consisting of V, Ti, Mg, Ca, Sr, B, Ga, In, Si and Ge) Formula: LiNi 1-c M 2 c O 2 (wherein, 0 ⁇ c ⁇ 0.5; M 2 is Fe, Co, Mn, Cu, Zn, Al, Sn, Cr, V, Ti, Mg, Ca, A lithium-nickel complex oxide represented by at least one metal selected from the group consisting of Sr, B, Ga, In, Si and Ge, or Formula: LiCo 1-d M 3 d O 2 (wherein 0 ⁇ d ⁇ 0.5; M 3 is Fe, Ni, Mn, Cu, Zn, Al, Sn,
  • LiNi 1/3 Co 1/3 Mn 1/3 O 2 is preferred.
  • LiFePO 4 LiNi 0.8 Co 0.2 O 2, Li 1.2 Fe 0.4 Mn 0.4 O 2, LiNi 0.5 Mn 0.5 O 2, LiV 3 O 6 etc. may be mentioned.
  • a compound having a two-dimensional layered structure such as TiS 2 or MoS 2 or a strong compound represented by the general formula Me x Mo 6 S 8 (Me is various transition metals including Pb, Ag, and Cu)
  • Me x Mo 6 S 8 Me is various transition metals including Pb, Ag, and Cu
  • Schbrel compounds having a three-dimensional framework structure a compound having a two-dimensional layered structure
  • elemental sulfur and organic lithium sulfides represented by LiS x and the like can also be mentioned.
  • Examples of the conductive polymer include p-doped conductive polymers and n-doped conductive polymers.
  • Examples of the conductive polymer include polyacetylene-based, polyphenylene-based, heterocyclic polymers, ionic polymers, ladders and network polymers.
  • lithium phosphate in the positive electrode active material because continuous charge characteristics are improved.
  • the lower limit of the amount of lithium phosphate used is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, and still more preferably 0.5% by mass, based on the total of the positive electrode active material and lithium phosphate. %, And the upper limit is preferably 10% by mass or less, more preferably 8% by mass or less, and still more preferably 5% by mass or less.
  • the substance of the composition different from this adhered on the surface of the said positive electrode active material As surface adhesion substances, aluminum oxide, silicon oxide, titanium oxide, zirconium oxide, magnesium oxide, calcium oxide, boron oxide, antimony oxide, oxides such as bismuth oxide, lithium sulfate, sodium sulfate, potassium sulfate, magnesium sulfate, calcium sulfate And sulfates such as aluminum sulfate, carbonates such as lithium carbonate, calcium carbonate and magnesium carbonate, and carbon.
  • surface adhesion substances aluminum oxide, silicon oxide, titanium oxide, zirconium oxide, magnesium oxide, calcium oxide, boron oxide, antimony oxide, oxides such as bismuth oxide, lithium sulfate, sodium sulfate, potassium sulfate, magnesium sulfate, calcium sulfate And sulfates such as aluminum sulfate, carbonates such as lithium carbonate, calcium carbonate and magnesium carbonate, and carbon.
  • surface adhesion substances are, for example, dissolved or suspended in a solvent and impregnated and added to the positive electrode active material and dried, or the surface adhesion substance precursor is dissolved or suspended in a solvent and impregnated into the positive electrode active material It can be made to adhere to the surface of the positive electrode active material by a method of reacting by heating or the like, a method of adding it to the positive electrode active material precursor and simultaneously baking it. In addition, when making carbon adhere, the method of making carbon quality adhere mechanically later, for example, in the form of activated carbon etc. can also be used.
  • the amount of the surface adhesion substance is preferably 0.1 ppm or more, more preferably 1 ppm or more, still more preferably 10 ppm or more, and preferably 20% or less as an upper limit, based on the mass of the positive electrode active material. Is used at 10% or less, more preferably 5% or less.
  • the surface adhesion substance can suppress the oxidation reaction of the electrolytic solution on the surface of the positive electrode active material, and the battery life can be improved. However, when the adhesion amount is too small, the effect is not sufficiently expressed. If it is too high, the resistance may increase to inhibit the lithium ion ingress and egress.
  • the shape of the particles of the positive electrode active material may, for example, be a block, a polyhedron, a sphere, an oval sphere, a plate, a needle, or a column as conventionally used.
  • primary particles may be aggregated to form secondary particles.
  • the tap density of the positive electrode active material is preferably 0.5 g / cm 3 or more, more preferably 0.8 g / cm 3 or more, and still more preferably 1.0 g / cm 3 or more.
  • the tap density of the positive electrode active material is below the above lower limit, the necessary amount of dispersion medium increases at the time of forming the positive electrode active material layer, and the required amount of the conductive material and the binder increases, and the positive electrode to the positive electrode active material layer
  • the filling rate of the active material may be limited, and the battery capacity may be limited.
  • a composite oxide powder with a high tap density a high density positive electrode active material layer can be formed.
  • the tap density is preferably as high as possible, and there is no particular upper limit.
  • the tap density is determined by placing 5 to 10 g of the positive electrode active material powder in a 10 ml glass measuring cylinder and tapping the powder packing density (tap density) g / cm 3 when tapping 200 times with a stroke of about 20 mm. Ask as.
  • the median diameter d50 of the particles of the positive electrode active material is preferably 0.3 ⁇ m or more, more preferably 0.5 ⁇ m or more, still more preferably Is preferably 0.8 ⁇ m or more, most preferably 1.0 ⁇ m or more, preferably 30 ⁇ m or less, more preferably 27 ⁇ m or less, still more preferably 25 ⁇ m or less, most preferably 22 ⁇ m or less. Below the lower limit, high tap density products may not be obtained.
  • the median diameter d50 is measured by a known laser diffraction / scattering type particle size distribution measuring apparatus.
  • LA-920 manufactured by HORIBA is used as a particle size distribution analyzer
  • a 0.1 mass% sodium hexametaphosphate aqueous solution is used as a dispersion medium for measurement, and a refractive index of 1.24 is set after ultrasonic dispersion for 5 minutes. Measured.
  • the average primary particle diameter of the positive electrode active material is preferably 0.05 ⁇ m or more, more preferably 0.1 ⁇ m or more, and still more preferably 0.
  • the upper limit is preferably 5 ⁇ m or less, more preferably 4 ⁇ m or less, still more preferably 3 ⁇ m or less, and most preferably 2 ⁇ m or less. If the above upper limit is exceeded, it is difficult to form spherical secondary particles, which adversely affects the powder packing property or significantly lowers the specific surface area, which may increase the possibility that battery performance such as output characteristics may be degraded. is there. On the other hand, if the lower limit is exceeded, usually problems such as poor reversibility of charge and discharge may occur due to underdeveloped crystals.
  • the primary particle diameter is measured by observation using a scanning electron microscope (SEM). Specifically, in a photograph at a magnification of 10000, the longest value of the intercept by the left and right boundary lines of the primary particle with respect to the straight line in the horizontal direction is obtained for any 50 primary particles, and the average value is obtained Be
  • BET specific surface area of the positive electrode active material is preferably 0.1 m 2 / g or more, more preferably 0.2 m 2 / g or more, further preferably 0.3 m 2 / g or more, and the upper limit is preferably 50 m 2 / It is not more than g, more preferably not more than 40 m 2 / g, still more preferably not more than 30 m 2 / g. If the BET specific surface area is smaller than this range, the battery performance tends to be deteriorated, and if the BET specific surface area is large, it is difficult to increase the tap density, and a problem may easily occur in the coatability when forming the positive electrode active material layer.
  • the BET specific surface area is determined by using a surface area meter (for example, a fully automatic surface area measuring device manufactured by Okura Riken Co., Ltd.) and predrying the sample for 30 minutes at 150 ° C. under nitrogen flow. It is defined as a value measured by a nitrogen adsorption BET one-point method by a gas flow method using a nitrogen-helium mixed gas which is accurately adjusted so that the value of the relative pressure of nitrogen to the atmospheric pressure is 0.3.
  • a surface area meter for example, a fully automatic surface area measuring device manufactured by Okura Riken Co., Ltd.
  • the particles of the positive electrode active material are mainly secondary particles. It is preferable that The particles of the positive electrode active material preferably contain 0.5 to 7.0% by volume of fine particles having an average particle diameter of secondary particles of 40 ⁇ m or less and an average primary particle diameter of 1 ⁇ m or less. By including fine particles having an average primary particle diameter of 1 ⁇ m or less, the contact area with the electrolytic solution becomes large, and the diffusion of lithium ions between the electrode and the electrolytic solution can be made faster, as a result, the battery Output performance can be improved.
  • a general method is used as a manufacturing method of an inorganic compound.
  • various methods can be considered to form spherical or elliptical spherical active materials.
  • a transition metal source material is dissolved or pulverized in a solvent such as water, and the pH is adjusted while stirring.
  • Spherical precursor is collected and dried, if necessary, added with a Li source such as LiOH, Li 2 CO 3 or LiNO 3 and calcined at high temperature to obtain an active material. .
  • the above-mentioned positive electrode active material may be used alone, or two or more of different compositions may be used in any combination or ratio.
  • a combination of LiCoO 2 and LiMn 2 O 4 such as LiNi 0.33 Co 0.33 Mn 0.33 O 2 or a part of this Mn substituted with another transition metal etc.
  • a combination of LiCoO 2 or a part of this Co substituted with another transition metal or the like may be used alone, or two or more of different compositions may be used in any combination or ratio.
  • a combination of LiCoO 2 and LiMn 2 O 4 such as LiNi 0.33 Co 0.33 Mn 0.33 O 2 or a part of this Mn substituted with another transition metal etc.
  • a combination of LiCoO 2 or a part of this Co substituted with another transition metal or the like may be used alone, or two or more of different compositions may be used in any combination or ratio.
  • the content of the positive electrode active material is preferably 50 to 99.5% by mass, and more preferably 80 to 99% by mass, of the positive electrode mixture in view of high battery capacity.
  • the content of the positive electrode active material in the positive electrode active material layer is preferably 80% by mass or more, more preferably 82% by mass or more, and particularly preferably 84% by mass or more.
  • the upper limit is preferably 99% by mass or less, more preferably 98% by mass or less. If the content of the positive electrode active material in the positive electrode active material layer is low, the electrical capacity may be insufficient. Conversely, if the content is too high, the strength of the positive electrode may be insufficient.
  • the positive electrode mixture preferably further contains a binder, a thickener, and a conductive material.
  • Any binder can be used as the binder as long as it is a material safe to the solvent and electrolyte used in the production of the electrode.
  • polyethylene, polypropylene, polyethylene terephthalate, polymethyl methacrylate, aroma -Based polymers such as chitosan, alginic acid, polyacrylic acid, polyimide, cellulose and nitrocellulose; SBR (styrene-butadiene rubber), isoprene rubber, butadiene rubber, fluororubber, NBR (acrylonitrile-butadiene rubber), ethylene ⁇ Rubber-like polymers such as propylene rubber; styrene / butadiene / styrene block copolymer or hydrogenated product thereof; EPDM (ethylene / propylene / diene terpolymer), styrene / ethylene / butadiene
  • the content of the binder is usually 0.1% by mass or more, preferably 1% by mass or more, more preferably 1.5% by mass or more, as a ratio of the binder in the positive electrode active material layer. Usually, it is 80% by mass or less, preferably 60% by mass or less, more preferably 40% by mass or less, and most preferably 10% by mass or less. If the proportion of the binder is too low, the positive electrode active material can not be sufficiently retained, and the mechanical strength of the positive electrode is insufficient, which may deteriorate battery performance such as cycle characteristics. On the other hand, if it is too high, it may lead to a decrease in battery capacity and conductivity.
  • thickener examples include carboxymethylcellulose, methylcellulose, hydroxymethylcellulose, ethylcellulose, polyvinyl alcohol, oxidized starch, phosphorylated starch, casein, polyvinyl pyrrolidone and salts thereof.
  • One type may be used alone, or two or more types may be used in any combination and ratio.
  • the ratio of the thickener to the active material is usually 0.1% by mass or more, preferably 0.2% by mass or more, more preferably 0.3% by mass or more, and usually 5% by mass or less, preferably 3 It is a range of not more than mass%, more preferably not more than 2 mass%. Below this range, the coatability may be significantly reduced. If it exceeds, the proportion of the active material in the positive electrode active material layer may be reduced, which may cause a problem of a decrease in battery capacity or an increase in resistance between the positive electrode active materials.
  • a well-known conductive material can be used arbitrarily as said conductive material.
  • Specific examples include metal materials such as copper and nickel, graphite (natural graphite), graphite such as artificial graphite, acetylene black, ketjen black, channel black, furnace black, lamp black, carbon black such as thermal black, needle coke And carbon materials such as carbon nanotubes, fullerenes, amorphous carbon such as VGCF, and the like.
  • metal materials such as copper and nickel, graphite (natural graphite), graphite such as artificial graphite, acetylene black, ketjen black, channel black, furnace black, lamp black, carbon black such as thermal black, needle coke And carbon materials such as carbon nanotubes, fullerenes, amorphous carbon such as VGCF, and the like.
  • these may be used individually by 1 type and may use 2 or more types together by arbitrary combinations and a ratio.
  • the conductive material is usually 0.01% by mass or more, preferably 0.1% by mass or more, more preferably 1% by mass or more, and usually 50% by mass or less, preferably 30% by mass, in the positive electrode active material layer. % Or less, more preferably 15% by mass or less. If the content is lower than this range, the conductivity may be insufficient. Conversely, if the content is higher than this range, the battery capacity may decrease.
  • an aqueous solvent or an organic solvent may be used.
  • the aqueous solvent include water and mixed solvents of alcohol and water.
  • organic solvents include aliphatic hydrocarbons such as hexane; aromatic hydrocarbons such as benzene, toluene, xylene and methylnaphthalene; heterocyclic compounds such as quinoline and pyridine; ketones such as acetone, methyl ethyl ketone and cyclohexanone Esters such as methyl acetate and methyl acrylate; Amines such as diethylenetriamine and N, N-dimethylaminopropylamine; Ethers such as diethyl ether, propylene oxide and tetrahydrofuran (THF); N-methylpyrrolidone (NMP) And amides such as dimethylformamide and dimethylacetamide; and aprotic polar solvents such as hexamethylphosphaamide and dimethylsulfoxide.
  • aliphatic hydrocarbons such as hexane
  • aromatic hydrocarbons such as benzene, toluene, xylene
  • Examples of the material of the current collector for the positive electrode include metals such as metals such as aluminum, titanium, tantalum, stainless steel and nickel, or alloys thereof; and carbon materials such as carbon cloth and carbon paper. Among them, metal materials, particularly aluminum or its alloy are preferable.
  • Examples of the shape of the current collector include metal foils, metal cylinders, metal coils, metal coils, metal plates, metal thin films, expanded metals, punched metals, foamed metals and the like in the case of metal materials, and in the case of carbon materials, carbon plates and carbons A thin film, a carbon cylinder, etc. are mentioned. Of these, metal thin films are preferred.
  • the thin film may be formed in a mesh shape as appropriate.
  • the thickness of the thin film is arbitrary, but is usually 1 ⁇ m or more, preferably 3 ⁇ m or more, more preferably 5 ⁇ m or more, and usually 1 mm or less, preferably 100 ⁇ m or less, more preferably 50 ⁇ m or less. If the thin film is thinner than this range, the strength required for the current collector may be insufficient. Conversely, if the thin film is thicker than this range, the handleability may be impaired.
  • the conductive support agent is apply
  • the conductive aid include carbon, and noble metals such as gold, platinum and silver.
  • the ratio of the thickness of the current collector to the thickness of the positive electrode active material layer is not particularly limited, but the value of (thickness of positive electrode active material layer on one side immediately before electrolyte injection) / (thickness of current collector) is 20 It is preferably the following, more preferably 15 or less, most preferably 10 or less, and preferably 0.5 or more, more preferably 0.8 or more, and most preferably 1 or more. If this range is exceeded, the current collector may generate Joule heat during high current density charge and discharge. Below this range, the volume ratio of the current collector to the positive electrode active material may increase, and the capacity of the battery may decrease.
  • the production of the positive electrode may be performed according to a conventional method.
  • the binder, thickener, conductive material, solvent and the like described above are added to the above-mentioned positive electrode active material to form a slurry-like positive electrode mixture, which is applied to a current collector, dried and pressed.
  • Density of the positive electrode active material layer is preferably 1.5 g / cm 3 or more, more preferably 2 g / cm 3 or more, still more preferably 2.2 g / cm 3 or more, preferably 5 g / cm 3 or less, More preferably, it is 4.5 g / cm 3 or less, further preferably 4 g / cm 3 or less. If this range is exceeded, the permeability of the electrolyte to the vicinity of the current collector / active material interface may be reduced, and in particular, the charge / discharge characteristics at high current densities may be reduced, and a high output may not be obtained. On the other hand, if it is lower than that, the conductivity between the active materials may be reduced, and the battery resistance may be increased to fail to obtain high output.
  • the area of the positive electrode active material layer is larger than the outer surface area of the battery case from the viewpoint of enhancing the stability at high output and high temperature.
  • the sum of the electrode area of the positive electrode to the surface area of the exterior of the secondary battery is preferably 15 times or more in area ratio, and more preferably 40 times or more.
  • the external surface area of the battery outer case is, in the case of a rectangular shape with a bottom, the total area obtained by calculation from the dimensions of the length, width, and thickness of the case portion filled with the power generation element excluding the protruding portion of the terminal.
  • the sum of the electrode area of the positive electrode is the geometric surface area of the positive electrode mixture layer facing the mixture layer containing the negative electrode active material, and in the structure formed by forming the positive electrode mixture layer on both sides via the current collector foil. , The sum of the area to calculate each face separately.
  • the thickness of the positive electrode plate is not particularly limited, but from the viewpoint of high capacity and high output, the thickness of the mixture layer obtained by subtracting the metal foil thickness of the core material is preferably set as the lower limit to one side of the current collector. Is preferably 10 ⁇ m or more, more preferably 20 ⁇ m or more, and preferably 500 ⁇ m or less, more preferably 450 ⁇ m or less.
  • the substance of the composition different from this adhered on the surface of the said positive electrode plate may be used as surface adhesion substances.
  • surface adhesion substances aluminum oxide, silicon oxide, titanium oxide, zirconium oxide, magnesium oxide, calcium oxide, boron oxide, antimony oxide, oxides such as bismuth oxide, lithium sulfate, sodium sulfate, potassium sulfate, magnesium sulfate, calcium sulfate And sulfates such as aluminum sulfate, carbonates such as lithium carbonate, calcium carbonate and magnesium carbonate, and carbon.
  • the negative electrode is composed of a negative electrode active material layer containing a negative electrode active material, and a current collector.
  • the negative electrode material is not particularly limited as long as it can electrochemically store and release lithium ions.
  • Specific examples include carbon materials, alloy materials, lithium-containing metal composite oxide materials, conductive polymers, and the like. One of these may be used alone, or two or more of these may be used in combination as desired.
  • the negative electrode active material a carbonaceous material capable of absorbing and desorbing lithium such as thermal decomposition products of organic matter and artificial graphite and natural graphite under various thermal decomposition conditions; and desorbing and releasing lithium such as tin oxide and silicon oxide Possible metal oxide materials; lithium metal; various lithium alloys; lithium-containing metal complex oxide materials and the like can be mentioned. These negative electrode active materials may be used as a mixture of two or more.
  • carbonaceous materials capable of storing and releasing lithium artificial graphite or purified natural graphite produced by high temperature treatment of graphitizable pitch obtained from various raw materials, or surface treatment of these graphites with pitch or other organic substances
  • the material is preferably obtained by carbonization after application of carbon, a carbonaceous material obtained by heat-treating natural graphite, artificial graphite, artificial carbonaceous material and artificial graphitic material at a temperature of 400
  • a carbonaceous material comprising at least two or more kinds of different crystalline carbonaceous materials and / or having an interface in which the different crystalline carbonaceous materials are in contact, and at least two or more different orientations of the negative electrode active material layer
  • the material selected from carbonaceous materials having an interface in contact with the carbonaceous material is more preferable because the balance between the initial irreversible capacity and the high current density charge / discharge characteristics is good.
  • these carbon materials may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.
  • a single lithium, a single metal and an alloy forming a lithium alloy, or oxidation thereof It may be any of compounds such as carbides, nitrides, silicides, sulfides or phosphides, and is not particularly limited.
  • the single metal and alloy forming the lithium alloy is preferably a material containing Group 13 and Group 14 metal / metalloid elements, more preferably aluminum, silicon and tin (hereinafter referred to as “specific metal elements”. And metals or alloys or compounds containing these atoms. One of these may be used alone, or two or more of these may be used in any combination and ratio.
  • a negative electrode active material having at least one kind of atom selected from specific metal elements, a metal simple substance of any one kind of specific metal element, an alloy composed of two or more kinds of specific metal elements, one kind or two kinds or more of specification Alloy consisting of metal element and one or more other metal elements, compound containing one or more specified metal elements, and oxide, carbide, nitride, silicide of the compound And complex compounds such as sulfides and phosphides.
  • bonded with several types of elements such as a simple metal, an alloy, or a nonmetallic element, etc. is also mentioned.
  • silicon and tin an alloy of these elements and a metal which does not operate as a negative electrode can be used.
  • tin a complex compound containing 5 to 6 elements in combination of a metal other than tin and silicon which acts as a negative electrode, a metal which does not further act as a negative electrode, and a nonmetallic element may be used it can.
  • the composite material which makes Si or Sn a 1st constitutent element, and contains the 2nd, 3rd constitutent element in addition to it is mentioned.
  • the second constituent element is, for example, at least one of cobalt, iron, magnesium, titanium, vanadium, chromium, manganese, nickel, copper, zinc, gallium and zirconium.
  • the third constituent element is, for example, at least one of boron, carbon, aluminum and phosphorus.
  • silicon or tin alone (may contain a trace amount of impurities), SiO v (0 ⁇ v ⁇ 2), SnO w (0) may be used as the metal material because high battery capacity and excellent battery characteristics can be obtained.
  • ⁇ w ⁇ 2), Si—Co—C composite, Si—Ni—C composite, Sn—Co—C composite, and Sn—Ni—C composite are preferable.
  • the lithium-containing metal complex oxide material used as the negative electrode active material is not particularly limited as long as it can occlude and release lithium, but a material containing titanium and lithium is preferable in terms of high current density charge and discharge characteristics, More preferably, a lithium-containing composite metal oxide material containing titanium is preferable, and a composite oxide of lithium and titanium (hereinafter abbreviated as "lithium-titanium composite oxide”) is more preferable. That is, when a lithium titanium composite oxide having a spinel structure is used by being contained in a negative electrode active material for an electrolyte battery, the output resistance is greatly reduced, which is particularly preferable.
  • lithium titanium complex oxide general formula: Li x Ti y M z O 4 [Wherein, M represents at least one element selected from the group consisting of Na, K, Co, Al, Fe, Ti, Mg, Cr, Ga, Cu, Zn and Nb. ] It is preferable that it is a compound represented by these.
  • Particularly preferable representative compositions of the above compounds are Li 4/3 Ti 5/3 O 4 in (i), Li 1 Ti 2 O 4 in (ii), and Li 4/5 Ti 11/5 O in (iii). 4
  • Li 4/3 Ti 4/3 Al 1/3 O 4 is mentioned as a preferable one.
  • the negative electrode mixture preferably further contains a binder, a thickener, and a conductive material.
  • the binding agent examples include the same as the binding agent that can be used for the positive electrode described above.
  • the ratio of the binder to the negative electrode active material is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, particularly preferably 0.6% by mass or more, and preferably 20% by mass or less, 15 Mass% or less is more preferable, 10 mass% or less is further preferable, and 8 mass% or less is particularly preferable.
  • the binder ratio in which the amount of the binder does not contribute to the battery capacity may increase, which may result in a decrease in the battery capacity. Moreover, if it is less than the said range, strength reduction of a negative electrode may be caused.
  • the ratio of the binder to the negative electrode active material is usually 0.1% by mass or more, and preferably 0.5% by mass or more.
  • the content is more preferably 0.6% by mass or more, and usually 5% by mass or less, preferably 3% by mass or less, and more preferably 2% by mass or less.
  • the ratio to the negative electrode active material is usually 1% by mass or more, preferably 2% by mass or more, and 3% by mass or more Moreover, it is 15 mass% or less normally, 10 mass% or less is preferable, and 8 mass% or less is still more preferable.
  • the ratio of the thickener to the negative electrode active material is usually 0.1% by mass or more, preferably 0.5% by mass or more, more preferably 0.6% by mass or more, and usually 5% by mass or less. 3 mass% or less is preferable, and 2 mass% or less is still more preferable.
  • the ratio of the thickener to the negative electrode active material is below the above range, the coatability may be significantly reduced. If the above range is exceeded, the proportion of the negative electrode active material in the negative electrode active material layer may be reduced, and the battery capacity may be reduced or the resistance between the negative electrode active material may be increased.
  • Examples of the conductive material of the negative electrode include metal materials such as copper and nickel; and carbon materials such as graphite and carbon black.
  • a solvent capable of dissolving or dispersing a negative electrode active material, a binder, a thickener used as needed, and a conductive material can be particularly selected.
  • a solvent capable of dissolving or dispersing a negative electrode active material, a binder, a thickener used as needed, and a conductive material can be particularly selected.
  • an aqueous solvent or an organic solvent may be used.
  • aqueous solvent examples include water, alcohol and the like
  • organic solvent examples include N-methylpyrrolidone (NMP), dimethylformamide, dimethylacetamide, methylacetamide, cyclohexanone, methyl acetate, methyl acrylate, diethyltriamine, N, N- Dimethylaminopropylamine, tetrahydrofuran (THF), toluene, acetone, diethyl ether, dimethylacetamide, hexamethylphosphide, dimethylsulfoxide, benzene, xylene, quinoline, pyridine, methylnaphthalene, hexane and the like can be mentioned.
  • Examples of the material of the current collector for the negative electrode include copper, nickel, and stainless steel. Among them, copper foil is preferable in terms of easy processing into a thin film and cost.
  • the thickness of the current collector is usually 1 ⁇ m or more, preferably 5 ⁇ m or more, and usually 100 ⁇ m or less, preferably 50 ⁇ m or less. If the thickness of the negative electrode current collector is too thick, the capacity of the entire battery may be too low. Conversely, if the thickness is too thin, the handling may be difficult.
  • the production of the negative electrode may be performed according to a conventional method.
  • the above-mentioned negative electrode material may be added with the above-mentioned binder, thickener, conductive material, solvent and the like to form a slurry, which is coated on a current collector, dried and then pressed to obtain high density.
  • the method of forming the thin film layer (negative electrode active material layer) containing the above-mentioned negative electrode active material by methods such as a vapor deposition method, a sputtering method, and a plating method, is also used.
  • the electrode structure when making the negative electrode active material into an electrode is not particularly limited, but the density of the negative electrode active material present on the current collector is preferably 1 g ⁇ cm ⁇ 3 or more, and 1.2 g ⁇ cm ⁇ 3 or more Is more preferable, 1.3 g ⁇ cm ⁇ 3 or more is particularly preferable, and 2.2 g ⁇ cm ⁇ 3 or less is preferable, 2.1 g ⁇ cm ⁇ 3 or less is more preferable, and 2.0 g ⁇ cm ⁇ 3 or less More preferably, it is particularly preferably 1.9 g ⁇ cm ⁇ 3 or less.
  • the density of the negative electrode active material present on the current collector exceeds the above range, the negative electrode active material particles are destroyed, and the initial irreversible capacity is increased, and the electrolyte solution near the current collector / negative electrode active material interface In some cases, the high current density charge / discharge characteristics may be deteriorated due to the decrease in the permeability of the If the above range is exceeded, the conductivity between the negative electrode active materials may be reduced, the battery resistance may be increased, and the capacity per unit volume may be reduced.
  • the thickness of the negative electrode plate is designed according to the positive electrode plate to be used and is not particularly limited, but the thickness of the mixture layer obtained by subtracting the metal foil thickness of the core material is usually 15 ⁇ m or more, preferably 20 ⁇ m or more More preferably, it is 30 ⁇ m or more, and usually 300 ⁇ m or less, preferably 280 ⁇ m or less, more preferably 250 ⁇ m or less.
  • the substance of the composition different from this adhered on the surface of the said negative electrode plate may be used as surface adhesion substances.
  • surface adhesion substances aluminum oxide, silicon oxide, titanium oxide, zirconium oxide, magnesium oxide, calcium oxide, boron oxide, antimony oxide, oxides such as bismuth oxide, lithium sulfate, sodium sulfate, potassium sulfate, magnesium sulfate, calcium sulfate And sulfates such as aluminum sulfate; and carbonates such as lithium carbonate, calcium carbonate, and magnesium carbonate.
  • the lithium ion secondary battery of the present invention preferably further comprises a separator.
  • the material and shape of the separator are not particularly limited as long as they are stable to the electrolytic solution and excellent in liquid retention, and known materials can be used. Among these, resins, glass fibers, inorganic substances, etc., which are formed of a material stable to the electrolytic solution of the present invention, are used, and porous sheet or non-woven fabric-like articles etc. excellent in liquid retention are used. preferable.
  • polyolefins such as polyethylene and a polypropylene, aromatic polyamide, polytetrafluoroethylene, polyether sulfone, a glass filter etc.
  • One of these materials such as polypropylene / polyethylene two-layer film, polypropylene / polyethylene / polypropylene three-layer film may be used alone, or two or more thereof may be used in any combination and ratio.
  • the separator is preferably a porous sheet or a non-woven fabric or the like that uses a polyolefin such as polyethylene or polypropylene as a raw material in that the permeability of the electrolytic solution and the shutdown effect are good.
  • the thickness of the separator is arbitrary, but is usually 1 ⁇ m or more, preferably 5 ⁇ m or more, more preferably 8 ⁇ m or more, and usually 50 ⁇ m or less, preferably 40 ⁇ m or less, still more preferably 30 ⁇ m or less. If the separator is thinner than the above range, the insulation and mechanical strength may be reduced. If the thickness is more than the above range, not only the battery performance such as rate characteristics may be degraded, but also the energy density of the entire electrolyte battery may be degraded.
  • the porosity of the separator is optional, but is usually 20% or more, preferably 35% or more, and more preferably 45% or more, Also, it is usually 90% or less, preferably 85% or less, and more preferably 75% or less.
  • the porosity is smaller than the above range, the film resistance tends to be increased and the rate characteristic tends to be deteriorated.
  • it is larger than the said range it exists in the tendency for the mechanical strength of a separator to fall and for insulation to fall.
  • the average pore diameter of the separator is also optional, but is usually 0.5 ⁇ m or less, preferably 0.2 ⁇ m or less, and usually 0.05 ⁇ m or more.
  • the average pore size exceeds the above range, a short circuit is likely to occur. If the above range is exceeded, the film resistance may increase and the rate characteristics may deteriorate.
  • oxides such as alumina and silicon dioxide
  • nitrides such as aluminum nitride and silicon nitride
  • sulfates such as barium sulfate and calcium sulfate are used, and those having a particle shape or fiber shape are used. Used.
  • a thin film such as a non-woven fabric, a woven fabric and a microporous film is used.
  • the thin film shape one having a pore diameter of 0.01 to 1 ⁇ m and a thickness of 5 to 50 ⁇ m is suitably used.
  • a separator can be used in which a composite porous layer containing particles of the above-mentioned inorganic substance is formed on the surface layer of the positive electrode and / or the negative electrode using a resin binder.
  • alumina particles having a 90% particle size of less than 1 ⁇ m may be formed on both sides of the positive electrode to form a porous layer using a fluorine resin as a binder.
  • the electrode group has a laminated structure in which the positive electrode plate and the negative electrode plate described above are intervened by the separator, and a structure in which the positive electrode plate and the negative electrode plate are spirally wound through the separator. Any one may be used.
  • the ratio of the volume of the electrode group to the internal volume of the battery (hereinafter referred to as the electrode group occupancy rate) is usually 40% or more, preferably 50% or more, and usually 90% or less, preferably 80% or less .
  • the battery capacity decreases. Further, when the above range is exceeded, the void space is small, the battery becomes high temperature, the members expand, the vapor pressure of the liquid component of the electrolyte becomes high, and the internal pressure rises, and the charge and discharge repetition performance as the battery And may deteriorate various characteristics such as high temperature storage, and may further operate a gas release valve that releases the internal pressure to the outside.
  • the current collecting structure is not particularly limited, in order to more effectively realize the improvement of the charge and discharge characteristics of the high current density by the electrolytic solution of the present invention, the structure of reducing the resistance of the wiring portion and the bonding portion may be used. preferable. When the internal resistance is thus reduced, the effect of using the electrolytic solution of the present invention is exhibited particularly well.
  • the electrode group has the above-described laminated structure
  • a structure formed by bundling metal core portions of the respective electrode layers and welding them to terminals is suitably used.
  • the internal resistance increases, so it is also preferable to provide a plurality of terminals in the electrode to reduce the resistance.
  • the electrode group has the above-described wound structure, the internal resistance can be lowered by providing a plurality of lead structures on the positive electrode and the negative electrode and bundling them in the terminals.
  • the material of the outer case is not particularly limited as long as the material is stable to the electrolyte used. Specifically, a nickel-plated steel sheet, metals such as stainless steel, aluminum or aluminum alloy, magnesium alloy or the like, or a laminated film (laminated film) of a resin and an aluminum foil is used. From the viewpoint of weight reduction, metals of aluminum or aluminum alloy and laminate films are preferably used.
  • the metals are welded to form a hermetically sealed structure by laser welding, resistance welding, ultrasonic welding, or a caulking structure is formed using the above metals via a resin gasket.
  • a resin gasket In the outer case using metals, the metals are welded to form a hermetically sealed structure by laser welding, resistance welding, ultrasonic welding, or a caulking structure is formed using the above metals via a resin gasket. The thing is mentioned.
  • those having a sealing and sealing structure by thermally fusing the resin layers to each other may be mentioned.
  • a resin different from the resin used for the laminate film may be interposed between the resin layers.
  • the metal and the resin are joined, and therefore, a resin having a polar group or a modification having a polar group introduced as an intervening resin Resin is preferably used.
  • the shape of the lithium ion secondary battery of the present invention is arbitrary, and examples thereof include cylindrical, square, laminate, coin and large shapes.
  • the shapes and configurations of the positive electrode, the negative electrode, and the separator can be changed and used according to the shapes of the respective batteries.
  • a module including the lithium ion secondary battery of the present invention is also one of the present invention.
  • a positive electrode, a negative electrode, and the above-described electrolyte solution wherein the positive electrode includes a positive electrode current collector and a positive electrode active material layer including a positive electrode active material, and the positive electrode active material includes Mn.
  • the lithium ion secondary battery is also one of the preferred embodiments. Since the positive electrode active material layer containing a positive electrode active material containing Mn is provided, the lithium ion secondary battery is further excellent in high-temperature storage characteristics.
  • LiMn 1.5 Ni 0.5 O 4 , LiNi 0.5 Co 0.2 Mn 0 .3 O 2 , LiNi 0.6 Co 0.2 Mn 0.2 O 2 is preferred.
  • the content of the positive electrode active material in the positive electrode active material layer is preferably 80% by mass or more, more preferably 82% by mass or more, and particularly preferably 84% by mass or more.
  • the upper limit is preferably 99% by mass or less, more preferably 98% by mass or less. If the content of the positive electrode active material in the positive electrode active material layer is low, the electrical capacity may be insufficient. Conversely, if the content is too high, the strength of the positive electrode may be insufficient.
  • the positive electrode active material layer may further contain a conductive material, a thickener and a binder.
  • any material can be used as long as it is a material safe to the solvent and the electrolyte used in the production of the electrode.
  • the content of the binder is usually 0.1% by mass or more, preferably 1% by mass or more, more preferably 1.5% by mass or more, as a ratio of the binder in the positive electrode active material layer. Usually, it is 80% by mass or less, preferably 60% by mass or less, more preferably 40% by mass or less, and most preferably 10% by mass or less. If the proportion of the binder is too low, the positive electrode active material can not be sufficiently retained, and the mechanical strength of the positive electrode is insufficient, which may deteriorate battery performance such as cycle characteristics. On the other hand, if it is too high, it may lead to a decrease in battery capacity and conductivity.
  • thickener examples include carboxymethylcellulose, methylcellulose, hydroxymethylcellulose, ethylcellulose, polyvinyl alcohol, oxidized starch, phosphorylated starch, casein and salts thereof.
  • One type may be used alone, or two or more types may be used in any combination and ratio.
  • the ratio of the thickener to the active material is usually 0.1% by mass or more, preferably 0.2% by mass or more, more preferably 0.3% by mass or more, and usually 5% by mass or less, preferably 3 It is a range of not more than mass%, more preferably not more than 2 mass%. Below this range, the coatability may be significantly reduced. If it exceeds, the proportion of the active material in the positive electrode active material layer may be reduced, which may cause a problem of a decrease in battery capacity or an increase in resistance between the positive electrode active materials.
  • a well-known conductive material can be used arbitrarily as said conductive material.
  • Specific examples thereof include metal materials such as copper and nickel, graphites such as natural graphite and artificial graphite, carbon blacks such as acetylene black, and carbon materials such as amorphous carbon such as needle coke. In addition, these may be used individually by 1 type and may use 2 or more types together by arbitrary combinations and a ratio.
  • the conductive material is usually 0.01% by mass or more, preferably 0.1% by mass or more, more preferably 1% by mass or more, and usually 50% by mass or less, preferably 30% by mass, in the positive electrode active material layer. % Or less, more preferably 15% by mass or less. If the content is lower than this range, the conductivity may be insufficient. Conversely, if the content is higher than this range, the battery capacity may decrease.
  • the positive electrode current collector is preferably made of a valve metal or an alloy thereof in order to further improve the high temperature storage characteristics.
  • a valve metal aluminum, titanium, a tantalum, chromium etc. are mentioned. More preferably, the positive electrode current collector is made of aluminum or an alloy of aluminum.
  • the lithium ion secondary battery is further improved in high temperature storage characteristics, so that the part in contact with the electrolytic solution among the parts electrically connected to the positive electrode current collector is also a valve metal or an alloy thereof. It is preferable that it is comprised.
  • a portion electrically connected to the positive electrode current collector and in contact with the non-aqueous electrolyte is a valve metal or It is preferable to comprise the alloy.
  • Stainless steel coated with valve metal or its alloy may be used.
  • the method for producing the positive electrode is as described above.
  • the above-mentioned binder, thickener, conductive material, solvent and the like are added to the above-mentioned positive electrode active material to obtain a slurry-like positive electrode mixture,
  • the configuration of the negative electrode is as described above.
  • the electric double layer capacitor may include a positive electrode, a negative electrode, and the above-described electrolytic solution.
  • at least one of the positive electrode and the negative electrode is a polarizable electrode, and the following electrodes described in detail in JP-A-9-7896 can be used as the polarizable electrode and the nonpolarizable electrode.
  • the polarizable electrode mainly composed of activated carbon used in the present invention preferably contains non-activated carbon having a large specific surface area and a conductive agent such as carbon black which imparts electron conductivity.
  • the polarizable electrode can be formed in various ways.
  • a polarizable electrode composed of activated carbon and carbon black can be formed by mixing activated carbon powder, carbon black and a phenolic resin, and after press molding, firing and firing in an inert gas atmosphere and a water vapor atmosphere.
  • the polarizable electrode is joined to the current collector with a conductive adhesive or the like.
  • activated carbon powder, carbon black and a binder may be kneaded in the presence of alcohol to form a sheet, which may be dried to form a polarizable electrode.
  • a polarizable electrode For example, polytetrafluoroethylene is used as the binder.
  • activated carbon powder, carbon black, a binder and a solvent are mixed to form a slurry, and the slurry is coated on a metal foil of a current collector and dried to form a polarizable electrode integrated with the current collector. it can.
  • a polarizable electrode mainly composed of activated carbon may be used as an electrical double layer capacitor for both electrodes
  • a nonpolarizable electrode may be used on one side, for example, a positive electrode mainly composed of a battery active material such as metal oxide, and activated carbon
  • a positive electrode mainly composed of a battery active material such as metal oxide such as metal oxide
  • activated carbon A combination of the polarizable electrode and the negative electrode of the main component, the negative electrode mainly of the carbon material capable of reversibly absorbing and desorbing lithium ions, or the negative electrode of lithium metal or lithium alloy and the active carbon as the main component
  • a configuration combining a positive pole is also possible.
  • a carbonaceous material such as carbon black, graphite, expanded graphite, porous carbon, carbon nanotube, carbon nanohorn, ketjen black may be used.
  • the non-polarizable electrode preferably, a carbon material capable of reversibly absorbing and desorbing lithium ions is mainly used, and the carbon material in which lithium ions are occluded is used for the electrode.
  • a lithium salt is used as the electrolyte. According to the electric double layer capacitor of this configuration, a further higher withstand voltage of 4 V can be obtained.
  • the solvent used for the preparation of the slurry in the preparation of the electrode is preferably one which dissolves the binder, and depending on the kind of binder, N-methylpyrrolidone, dimethylformamide, toluene, xylene, isophorone, methyl ethyl ketone, ethyl acetate, methyl acetate, phthalate
  • N-methylpyrrolidone dimethylformamide
  • toluene toluene
  • xylene isophorone
  • methyl ethyl ketone ethyl acetate
  • methyl acetate phthalate
  • the acid dimethyl, ethanol, methanol, butanol or water are chosen accordingly.
  • the activated carbon used for the polarizable electrode examples include phenol resin-based activated carbon, coconut-based activated carbon, and petroleum coke-based activated carbon. Among these, it is preferable to use petroleum coke-based activated carbon or phenol resin-based activated carbon in that a large capacity can be obtained.
  • the activation treatment method of activated carbon includes a steam activation treatment method, a molten KOH activation treatment method, and the like, and it is preferable to use activated carbon by the molten KOH activation treatment method in that a larger capacity can be obtained.
  • Preferable conductive agents used for the polarizable electrode include carbon black, ketjen black, acetylene black, natural graphite, artificial graphite, metal fibers, conductive titanium oxide and ruthenium oxide.
  • the mixing amount of a conductive agent such as carbon black used for the polarizable electrode is 1 to 10% of the total amount with the activated carbon to obtain good conductivity (low internal resistance) or reduce the capacity of the product when too large. It is preferable to set it as 50 mass%.
  • activated carbon used for the polarizable electrode activated carbon having an average particle diameter of 20 ⁇ m or less and a specific surface area of 1500 to 3000 m 2 / g is used so that a large capacity and low internal resistance electric double layer capacitor can be obtained. Is preferred.
  • preferable carbon materials for constituting an electrode composed mainly of a carbon material capable of reversibly absorbing and desorbing lithium ions natural graphite, artificial graphite, graphitized mesocarbon small spheres, graphitized whiskers, gas layer A grown carbon fiber, a baked product of furfuryl alcohol resin or a baked product of novolak resin may be mentioned.
  • the current collector may be any one that is chemically and electrochemically corrosion resistant.
  • Stainless steel, aluminum, titanium or tantalum can be preferably used as the current collector of the polarizable electrode mainly composed of activated carbon.
  • stainless steel or aluminum is a particularly preferable material in terms of both the properties and the cost of the obtained electric double layer capacitor.
  • stainless steel, copper or nickel is used as a current collector of an electrode composed mainly of a carbon material capable of reversibly absorbing and desorbing lithium ions.
  • a powdery lithium is mixed with a carbon material capable of reversibly absorbing and desorbing lithium ions
  • a lithium foil is placed on an electrode formed of a carbon material capable of reversibly absorbing and desorbing lithium ions and a binder, and the electrode is a lithium salt in a state of being in electrical contact with the electrode.
  • Lithium is ionized by immersing in a molten electrolyte and lithium ions are incorporated into the carbon material, (3) formed by the carbon material and the binder capable of reversibly absorbing and desorbing lithium ions
  • the electrode is placed on the negative side, lithium metal is placed on the positive side, and it is immersed in a non-aqueous electrolyte solution using lithium salt as the electrolyte, and a carbon material is electrochemically supplied by passing an electric current.
  • the electric double layer capacitor As the electric double layer capacitor, a wound type electric double layer capacitor, a laminate type electric double layer capacitor, a coin type electric double layer capacitor and the like are generally known, and the above electric double layer capacitor can also be in these types. .
  • a positive electrode and a negative electrode composed of a laminate (electrode) of a current collector and an electrode layer are wound via a separator to produce a wound element, and this wound element is made of aluminum Etc., filled with an electrolytic solution, preferably a non-aqueous electrolytic solution, and then sealed by sealing with a rubber sealing body.
  • separator those of conventionally known materials and constitutions can be used.
  • polyethylene porous membrane, polytetrafluoroethylene, polypropylene fiber or glass fiber, non-woven fabric of cellulose fiber, etc. may be mentioned.
  • a laminate type electric double layer capacitor in which sheet-like positive and negative electrodes are stacked via an electrolytic solution and a separator by a known method, or a gasket is fixed to make the positive and negative electrodes coin-shaped through the electrolytic solution and the separator.
  • a coin-type electric double layer capacitor can also be configured.
  • the electrolytic solution of the present invention is useful as an electrolytic solution for a large-sized lithium ion secondary battery for a hybrid automobile or for a dispersed power source, and for an electric double layer capacitor.
  • LiPF 6 was added to a mixture of ethylene carbonate (EC) and ethyl methyl carbonate (EMC) (volume ratio: 30:70) to a concentration of 1.0 mol / l to prepare a basic electrolyte. Further, methyl allyl oxalate, diallyl oxalate and dimethyl oxalate were added to this electrolytic solution to a content described in Table 1 to obtain a non-aqueous electrolytic solution. In addition, content of each addition compound in each table
  • Example 9 In Example 4, ethyl allyl oxalate and diethyl oxalate were added instead of methyl allyl oxalate and dimethyl oxalate to obtain a non-aqueous electrolyte.
  • Example 10 In Example 4, methyl allyl carbonate was further added to a content described in Table 1 to obtain a non-aqueous electrolytic solution.
  • Example 11 LiPF 6 was added to a mixture of ethylene carbonate (EC) and dimethyl carbonate (DMC) (volume ratio: 30:70) to a concentration of 1.0 mol / l to prepare a basic electrolyte. Further, methyl allyl oxalate, diallyl oxalate and dimethyl oxalate were added to this electrolytic solution to a content described in Table 1 to obtain a non-aqueous electrolytic solution.
  • EC ethylene carbonate
  • DMC dimethyl carbonate
  • Example 12 LiPF 6 was added to a mixture of ethylene carbonate (EC) and ethyl propionate (EP) (volume ratio: 30:70) to a concentration of 1.0 mol / l to prepare a basic electrolyte. Further, methyl allyl oxalate, diallyl oxalate and dimethyl oxalate were added to this electrolytic solution to a content described in Table 1 to obtain a non-aqueous electrolytic solution.
  • EC ethylene carbonate
  • EP ethyl propionate
  • Example 1 preparation was made without addition of methyl allyl oxalate, diallyl oxalate and dimethyl oxalate to obtain a non-aqueous electrolytic solution.
  • Comparative example 2 Further, diethyl oxalate was added to the electrolytic solution of Comparative Example 1 to a content described in Table 1 to obtain a non-aqueous electrolytic solution.
  • the obtained slurry is applied to a copper foil with a thickness of 10 ⁇ m, dried, and rolled with a press, and the size of the active material layer is 52 mm in width, 32 mm in length, and 5 mm in width, 9 mm in length. It cut out to the shape which has a part, and was set as the negative electrode.
  • the positive electrode and the negative electrode are made to face each other through a microporous polyethylene film (separator) having a thickness of 20 ⁇ m and the non-aqueous electrolytic solution obtained above is injected, and the non-aqueous electrolytic solution is sufficiently used as a separator. After penetration, the battery was sealed, pre-charged and aged to prepare a lithium ion secondary battery.
  • 1 C represents a current value for discharging the reference capacity of the battery in one hour
  • 5 C represents a current value five times that of 0.1 C
  • 1 C represents a current value 1/10 that of 0.2 C. Represents a current value of 1 ⁇ 5.
  • Example 13 LiPF 6 was added to a mixture of ethylene carbonate (EC) and ethyl methyl carbonate (EMC) (volume ratio: 30:70) to a concentration of 1.2 mol / l to prepare a basic electrolyte. Further, methyl allyl oxalate, diallyl oxalate, dimethyl oxalate and vinylene carbonate (VC) were added to this electrolytic solution to the contents described in Table 2 to obtain a non-aqueous electrolytic solution.
  • EC ethylene carbonate
  • EMC ethyl methyl carbonate
  • VC vinylene carbonate
  • Example 14 lithium bisoxalato borate (LiBOB) was added instead of VC to a content described in Table 2 to obtain a non-aqueous electrolytic solution.
  • LiBOB lithium bisoxalato borate
  • Example 15 lithium difluorophosphate (LiPO 2 F 2 ) was added in place of VC to a content described in Table 2 to obtain a non-aqueous electrolytic solution.
  • LiPO 2 F 2 lithium difluorophosphate
  • Example 16 lithium fluorosulfonate (FSO 3 Li) was added in place of VC to a content described in Table 2 to obtain a non-aqueous electrolytic solution.
  • FSO 3 Li lithium fluorosulfonate
  • Example 17 In Example 13, ethyl lithium sulfate (C 2 H 5 OSO 3 Li) was added in place of VC to a content described in Table 2 to obtain a non-aqueous electrolytic solution.
  • ethyl lithium sulfate C 2 H 5 OSO 3 Li
  • Example 18 In Example 13, a non-aqueous electrolytic solution was obtained by adding fluoroethylene carbonate (FEC) to the content described in Table 2 instead of VC.
  • FEC fluoroethylene carbonate
  • Example 19 In Example 13, 4- (2,2,3,3,3-pentafluoro-propyl)-[1,3] dioxolan-2-one (CF 3 CF 2 CH 2 -EC) is used in place of VC. It added so that it might become content described in 2, and the non-aqueous electrolyte was obtained.
  • CF 3 CF 2 CH 2 -EC (2,2,3,3,3-pentafluoro-propyl)-[1,3] dioxolan-2-one
  • Example 20 In Example 13, instead of methyl allyl oxalate and dimethyl oxalate, ethyl allyl oxalate and diethyl oxalate were added to obtain a non-aqueous electrolytic solution.
  • Comparative example 3 The basic electrolyte described in Example 13 was used as the non-aqueous electrolyte of Comparative Example 3.
  • Comparative example 4 In Comparative Example 3, diethyl oxalate and VC were added to the contents described in Table 2 to obtain a non-aqueous electrolytic solution.
  • Comparative example 5 In Comparative Example 3, di (2-propynyl) oxalate and VC were added to the contents described in Table 2 to obtain a non-aqueous electrolytic solution.
  • Comparative example 6 In Comparative Example 3, diallyl oxalate and VC were added to the contents described in Table 2 to obtain a non-aqueous electrolytic solution.
  • Comparative example 7 In Comparative Example 3, methyl allyl oxalate and LiPO 2 F 2 were added to the contents described in Table 2 to obtain a non-aqueous electrolytic solution.
  • Comparative Example 8 In Comparative Example 3, ethyl allyl oxalate and LiPO 2 F 2 were added to the contents described in Table 2 to obtain a non-aqueous electrolytic solution.
  • a lithium ion secondary battery was produced in the same manner as in Example 1 except that the non-aqueous electrolytes described in Examples 13 to 20 and Comparative Examples 3 to 8 were used.
  • the lithium ion secondary battery manufactured above is charged to 4.2 V at a constant current corresponding to 0.2 C at 25 ° C. in a state of sandwiching and pressing with a plate, and then 3. It discharged to 0V. This is done 2 cycles to stabilize the battery, and in the third cycle, after charging to 4.2 V with a constant current of 0.2 C, charge to a current value of 0.05 C with a constant voltage of 4.2 V And was discharged to 3.0 V with a constant current of 0.2C. Thereafter, in the fourth cycle, after charging to 4.2 V with a constant current of 0.2 C, charging is performed at a constant voltage of 4.2 V until the current value reaches 0.05 C, and 3. It discharged to 0 V and calculated
  • Example 21 LiPF 6 was added to a mixture of trifluoropropylene carbonate and methyl 2,2,2-trifluoroethyl carbonate (volume ratio: 30:70) to a concentration of 1.0 mol / l to prepare a basic electrolyte. Further, methyl allyl oxalate, diallyl oxalate and dimethyl oxalate were added to this electrolytic solution to a content described in Table 3 to obtain a non-aqueous electrolytic solution.
  • Example 22 LiPF 6 was added to a mixture of trifluoropropylene carbonate and methyl difluoroacetate (volume ratio 30:70) to a concentration of 1.0 mol / l to prepare a basic electrolyte. Further, methyl allyl oxalate, diallyl oxalate and dimethyl oxalate were added to this electrolytic solution to a content described in Table 3 to obtain a non-aqueous electrolytic solution.
  • Example 23 LiPF 6 is added to a mixture of fluoroethylene carbonate (FEC) and methyl 2,2,2-trifluoroethyl carbonate (volume ratio 30:70) to a concentration of 1.0 mol / l to obtain a basic electrolyte did. Further, methyl allyl oxalate, diallyl oxalate and dimethyl oxalate were added to this electrolytic solution to a content described in Table 3 to obtain a non-aqueous electrolytic solution.
  • FEC fluoroethylene carbonate
  • methyl 2,2,2-trifluoroethyl carbonate volume ratio 30:70
  • Example 24 LiPF 6 was added to a mixture of fluoroethylene carbonate (FEC) and methyl difluoroacetate (volume ratio 30:70) to a concentration of 1.0 mol / l to prepare a basic electrolyte. Further, methyl allyl oxalate, diallyl oxalate and dimethyl oxalate were added to this electrolytic solution to a content described in Table 3 to obtain a non-aqueous electrolytic solution.
  • FEC fluoroethylene carbonate
  • methyl difluoroacetate volume ratio 30:70
  • Example 25 Add LiPF 6 to a mixture of fluoroethylene carbonate (FEC) and methyl 3,3,3-trifluoropropionate (volume ratio 30:70) to give a concentration of 1.0 mol / l, and did. Further, methyl allyl oxalate, diallyl oxalate and dimethyl oxalate were added to this electrolytic solution to a content described in Table 3 to obtain a non-aqueous electrolytic solution.
  • FEC fluoroethylene carbonate
  • methyl 3,3,3-trifluoropropionate volume ratio 30:70
  • Example 26 In Example 24, instead of methyl allyl oxalate and dimethyl oxalate, ethyl allyl oxalate and diethyl oxalate were added to obtain a non-aqueous electrolytic solution.
  • Comparative Example 9 The basic electrolyte described in Example 21 was used as the non-aqueous electrolyte of Comparative Example 9.
  • Comparative example 10 The base electrolyte described in Example 22 was used as the non-aqueous electrolyte of Comparative Example 10.
  • Comparative example 11 The basic electrolyte described in Example 23 was used as the non-aqueous electrolyte of Comparative Example 11.
  • Comparative Example 12 The basic electrolyte described in Example 24 was used as the non-aqueous electrolyte of Comparative Example 12.
  • Comparative Example 13 The basic electrolyte described in Example 25 was used as the non-aqueous electrolyte of Comparative Example 13.
  • Comparative Example 14 In the electrolytic solution described in Comparative Example 9, dimethyl oxalate was added to a content described in Table 3 to obtain a non-aqueous electrolytic solution.
  • Comparative example 15 In the electrolytic solution described in Comparative Example 11, dimethyl oxalate was added to a content described in Table 3 to obtain a non-aqueous electrolytic solution.
  • a lithium ion secondary battery was produced in the same manner as in Example 1 except that the non-aqueous electrolytes described in Examples 21 to 26 and Comparative Examples 9 to 15 were used.

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Abstract

Provided is an electrolyte solution that can improve the high-temperature storage characteristics and cycle characteristics of electrochemical devices. The electrolyte solution is characterized by comprising compound (1) represented by general formula (1) (in the formula, R101 is an alkyl group having 1 to 4 carbons and R102 is an alkenyl group having 2 to 4 carbons) and at least one selected from the group consisting of compound (11) represented by general formula (11) (in the formula, R101 is defined as above) and compound (12) represented by general formula (12) (in the formula, R102 is defined as above).

Description

電解液、電気化学デバイス、リチウムイオン二次電池及びモジュールElectrolyte, electrochemical device, lithium ion secondary battery and module
本発明は、電解液、電気化学デバイス、リチウムイオン二次電池及びモジュールに関する。 The present invention relates to an electrolytic solution, an electrochemical device, a lithium ion secondary battery and a module.
近年の電気製品の軽量化、小型化にともない、高いエネルギー密度をもつリチウムイオン二次電池等の電気化学デバイスの開発が進められている。また、リチウムイオン二次電池等の電気化学デバイスの適用分野が拡大するにつれて特性の改善が要望されている。特に今後、車載用にリチウムイオン二次電池が使われた場合、電池特性の改善はますます重要となる。 With the reduction in weight and size of electric products in recent years, development of electrochemical devices such as lithium ion secondary batteries having high energy density has been promoted. Further, as the application field of electrochemical devices such as lithium ion secondary batteries is expanded, there is a demand for improvement of the characteristics. In the future, especially when lithium ion secondary batteries are used for vehicles, improvement of battery characteristics becomes increasingly important.
特許文献１には、炭酸エステル、エーテル及びラクトンからなる群から選ばれる少なくとも１種の非水系溶媒を主体とする溶媒にリチウム塩を溶解してなる電解液において、上記溶媒がジカルボン酸ジエステル（但し、コハク酸ジエステルを除く）又はその誘導体と分子量５００以下の芳香族化合物とを含有することを特徴とする電解液が記載されている。 In Patent Document 1, in the electrolytic solution obtained by dissolving a lithium salt in a solvent mainly composed of at least one non-aqueous solvent selected from the group consisting of carbonate ester, ether and lactone, the solvent is a dicarboxylic acid diester (wherein An electrolytic solution is described which is characterized in that it contains a succinic acid diester) or a derivative thereof and an aromatic compound having a molecular weight of 500 or less.
特許文献２には、非水電解液中にビニレンカーボネート及びジ（２－プロピニル）オギザレートを含み、前記ビニレンカーボネートの添加量は前記非水電解液の質量に対して０．１質量％以上３質量％以下であり、前記ジ（２－プロピニル）オギザレートの添加量は前記非水電解液の質量に対して０．１質量％以上２質量％以下であり、前記非水電解液はエチレンカーボネートと非環状カーボネートとの混合溶媒からなり、前記エチレンカーボネートの含有割合は前記混合溶媒の２０体積％以上４０体積％以下である非水電解液二次電池が記載されている。 In Patent Document 2, the non-aqueous electrolyte contains vinylene carbonate and di (2-propynyl) oxalate, and the addition amount of the vinylene carbonate is 0.1% by mass or more and 3% by mass with respect to the mass of the non-aqueous electrolyte. % Or less, and the addition amount of the di (2-propynyl) oxalate is 0.1% by mass or more and 2% by mass or less with respect to the mass of the non-aqueous electrolyte, and the non-aqueous electrolyte contains ethylene carbonate and non-ethylene carbonate. A non-aqueous electrolyte secondary battery is described which is composed of a mixed solvent with a cyclic carbonate, and the content of the ethylene carbonate is 20% by volume or more and 40% by volume or less of the mixed solvent.
特許文献３には、正極および負極と共に電解液を備え、前記電解液は、非水溶媒と、電解質塩と、特定の化合物の組み合わせを含む、二次電池が記載されている。 Patent Document 3 describes a secondary battery that includes an electrolytic solution together with a positive electrode and a negative electrode, and the electrolytic solution contains a combination of a non-aqueous solvent, an electrolyte salt, and a specific compound.
特許文献４には、溶媒、及び、電解質塩を含む電解液であって、前記溶媒は、電解液中０．００１～１０ｐｐｍの一般式（Ａ）で示される化合物（Ａ）を含むことを特徴とする電解液が記載されている。
Figure JPOXMLDOC01-appb-C000004
 （式中、Ｒ１及びＲ２は、同一又は異なっていてもよく、炭素数１～７のアルキル基である。） Patent Document 4 is an electrolytic solution containing a solvent and an electrolyte salt, and the solvent contains 0.001 to 10 ppm of the compound (A) represented by the general formula (A) in the electrolytic solution. An electrolytic solution is described.
Figure JPOXMLDOC01-appb-C000004
 (In the formula, R 1 and R 2 may be the same or different, and are an alkyl group having 1 to 7 carbon atoms.)
特開２００２－３６７６７４号公報Unexamined-Japanese-Patent No. 2002-367674 特開２００９－１１７３８３号公報JP, 2009-117383, A 特開２０１１－２３８３７３号公報JP, 2011-238373, A 国際公開第２０１５／０８３７４７号WO 2015/083747
しかしながら、これまでの技術は電気化学デバイスの高温保存特性やサイクル特性の向上において十分でなかった。 However, the conventional techniques have not been sufficient in improving the high temperature storage characteristics and cycle characteristics of electrochemical devices.
本発明は、上記現状に鑑みてなされたものであり、電気化学デバイスの高温保存特性及びサイクル特性を向上させることができる電解液、及び、当該電解液を備える電気化学デバイスを提供することを目的とする。 The present invention was made in view of the above-mentioned present situation, and it is an object of the present invention to provide an electrolytic solution capable of improving high temperature storage characteristics and cycle characteristics of an electrochemical device, and an electrochemical device provided with the electrolytic solution. I assume.
本発明者らは、特定の構造を有するシュウ酸エステル化合物を２種類以上含む場合に、上記課題が見事に解決されることを見出し、本発明を完成するに至った。 The inventors of the present invention have found that the above-mentioned problems can be satisfactorily solved when two or more kinds of oxalic acid ester compounds having a specific structure are contained, and the present invention has been accomplished.
本発明は、下記一般式（１）で表される化合物（１）と、下記一般式（１１）で表される化合物（１１）及び下記一般式（１２）で表される化合物（１２）からなる群より選択される少なくとも１種とを含むことを特徴とする電解液である。
一般式（１）：
Figure JPOXMLDOC01-appb-C000005
 （式中、Ｒ１０１は炭素数１～４のアルキル基であり、Ｒ１０２は炭素数２～４のアルケニル基である。）
一般式（１１）：
Figure JPOXMLDOC01-appb-C000006
 （式中、Ｒ１０１は上記と同じである。）
一般式（１２）：
Figure JPOXMLDOC01-appb-C000007
 （式中、Ｒ１０２は上記と同じである。） The present invention relates to a compound (1) represented by the following general formula (1), a compound (11) represented by the following general formula (11), and a compound (12) represented by the following general formula (12) And at least one selected from the group consisting of
General formula (1):
Figure JPOXMLDOC01-appb-C000005
 (Wherein, R 101 is an alkyl group having 1 to 4 carbon atoms, and R 102 is an alkenyl group having 2 to 4 carbon atoms.)
General formula (11):
Figure JPOXMLDOC01-appb-C000006
 (Wherein, R 101 is the same as above).
General formula (12):
Figure JPOXMLDOC01-appb-C000007
 (Wherein, R 102 is the same as above)
本発明は、上記電解液を備えることを特徴とする電気化学デバイスでもある。 The present invention is also an electrochemical device comprising the above-mentioned electrolytic solution.
本発明は、上記電解液を備えることを特徴とするリチウムイオン二次電池でもある。 The present invention is also a lithium ion secondary battery comprising the above-mentioned electrolytic solution.
本発明は、上記電気化学デバイス、又は、上記リチウムイオン二次電池を備えることを特徴とするモジュールでもある。 The present invention is also a module including the electrochemical device or the lithium ion secondary battery.
本発明の電解液によれば、電気化学デバイスの高温保存特性及びサイクル特性を向上させることができる。上記電解液を備える電気化学デバイスは、高温保存特性及びサイクル特性に優れる。 According to the electrolytic solution of the present invention, high temperature storage characteristics and cycle characteristics of the electrochemical device can be improved. The electrochemical device provided with the above-mentioned electrolytic solution is excellent in high-temperature storage characteristics and cycle characteristics.
以下、本発明を具体的に説明する。 Hereinafter, the present invention will be specifically described.
本発明の電解液は、下記一般式（１）：
Figure JPOXMLDOC01-appb-C000008
 で表される化合物（１）と、下記一般式（１１）：
Figure JPOXMLDOC01-appb-C000009
 で表される化合物（１１）及び下記一般式（１２）：
Figure JPOXMLDOC01-appb-C000010
 で表される化合物（１２）からなる群より選択される少なくとも１種とを含むことを特徴とする。この特徴により、本発明の電解液は、電気化学デバイスの高温保存特性及びサイクル特性を向上させることができる。 The electrolytic solution of the present invention has the following general formula (1):
Figure JPOXMLDOC01-appb-C000008
 And a compound (1) represented by the following general formula (11):
Figure JPOXMLDOC01-appb-C000009
 The compound (11) represented by and the following general formula (12):
Figure JPOXMLDOC01-appb-C000010
 And at least one selected from the group consisting of compounds (12) Due to this feature, the electrolytic solution of the present invention can improve the high temperature storage characteristics and cycle characteristics of the electrochemical device.
一般式（１）及び（１１）中、Ｒ１０１は炭素数１～４のアルキル基である。Ｒ１０１の炭素数は、１～３であることが好ましく、１～２であることがより好ましい。
Ｒ１０１としては、メチル基（－ＣＨ３）、エチル基（－ＣＨ２ＣＨ３）が好ましい。
上記アルキル基は、フッ素原子を有していないことが好ましく、ハロゲン原子を有していないことがより好ましい。 In the general formulas (1) and (11), R 101 is an alkyl group having 1 to 4 carbon atoms. The carbon number of R 101 is preferably 1 to 3, and more preferably 1 to 2.
As R 101 , a methyl group (—CH 3 ) and an ethyl group (—CH 2 CH 3 ) are preferable.
It is preferable that the said alkyl group does not have a fluorine atom, and it is more preferable that it does not have a halogen atom.
一般式（１）及び（１２）中、Ｒ１０２は炭素数２～４のアルケニル基である。 In the general formulas (1) and (12), R 102 is an alkenyl group having 2 to 4 carbon atoms.
上記アルケニル基としては、エテニル基（－ＣＨ＝ＣＨ２）、１－プロペニル基（－ＣＨ＝ＣＨ－ＣＨ３）、１－メチルエテニル基（－Ｃ（ＣＨ３）＝ＣＨ２）、２－プロペニル基（－ＣＨ２－ＣＨ＝ＣＨ２）、１－ブテニル基（－ＣＨ＝ＣＨ－ＣＨ２ＣＨ３）、２－メチル－１－プロペニル基（－ＣＨ＝Ｃ（ＣＨ３）－ＣＨ３）、１－メチル－１－プロペニル基（－Ｃ（ＣＨ３）＝ＣＨ－ＣＨ３）、１－エチルエテニル基（－Ｃ（ＣＨ２ＣＨ３）＝ＣＨ２）、２－ブテニル基（－ＣＨ２－ＣＨ＝ＣＨ２－ＣＨ３）、２－メチル－２－プロペニル基（－ＣＨ２－Ｃ（ＣＨ３）＝ＣＨ２）、１－メチル－２－プロペニル基（－ＣＨ（ＣＨ３）－ＣＨ＝ＣＨ２）、３－ブテニル基（－ＣＨ２ＣＨ２－ＣＨ＝ＣＨ２）、１－メチレン－２－プロペニル基（－Ｃ（＝ＣＨ２）－ＣＨ＝ＣＨ２）、１，３－ブタジエニル基（－ＣＨ＝ＣＨ－ＣＨ＝ＣＨ２）、２，３－ブタジエニル基（－ＣＨ２－ＣＨ＝Ｃ＝ＣＨ２）、１－メチル－１，２－プロパジエニル基（－Ｃ（ＣＨ３）＝Ｃ＝ＣＨ２）、１，２－ブタジエニル基（－ＣＨ＝Ｃ＝ＣＨ－ＣＨ３）が好ましく、２－プロペニル基（－ＣＨ２－ＣＨ＝ＣＨ２）、２－ブテニル基（－ＣＨ２－ＣＨ＝ＣＨ２－ＣＨ３）、２－メチル－２－プロペニル基（－ＣＨ２－Ｃ（ＣＨ３）＝ＣＨ２）、１－メチル－２－プロペニル基（－ＣＨ（ＣＨ３）－ＣＨ＝ＣＨ２）、３－ブテニル基（－ＣＨ２ＣＨ２－ＣＨ＝ＣＨ２）がより好ましい。
上記アルケニル基は、フッ素原子を有していないことが好ましく、ハロゲン原子を有していないことがより好ましい。 Examples of the alkenyl group include ethenyl group (-CH = CH 2 ), 1-propenyl group (-CH = CH-CH 3 ), 1-methylethenyl group (-C (CH 3 ) = CH 2 ), 2-propenyl group (-CH 2 -CH = CH 2 ), 1-butenyl group (-CH = CH-CH 2 CH 3 ), 2-methyl-1-propenyl group (-CH = C (CH 3 ) -CH 3 ), 1 - methyl-1-propenyl group (-C (CH 3) = CH -CH 3), 1- Echirueteniru group (-C (CH 2 CH 3) = CH 2), 2- butenyl group (-CH 2 -CH = CH 2 -CH 3 ), 2-methyl-2-propenyl group (-CH 2 -C (CH 3 ) = CH 2 ), 1-methyl-2-propenyl group (-CH (CH 3 ) -CH = CH 2 ), 3-butenyl group (-CH 2 CH 2 -CH = C 2), 1-methylene-2-propenyl group (-C (= CH 2) -CH = CH 2), 1,3- butadienyl group (-CH = CH-CH = CH 2), 2,3- butadienyl group (-CH 2 -CH = C = CH 2 ), 1-methyl-1,2-propadienyl group (-C (CH 3 ) = C = CH 2 ), 1,2-butadienyl group (-CH = C = CH -CH 3 ) is preferable, and 2-propenyl group (-CH 2 -CH = CH 2 ), 2-butenyl group (-CH 2 -CH = CH 2 -CH 3 ), 2-methyl-2-propenyl group (- CH 2 -C (CH 3 ) = CH 2 ), 1-methyl-2-propenyl group (-CH (CH 3 ) -CH = CH 2 ), 3-butenyl group (-CH 2 CH 2 -CH = CH 2) Is more preferred.
It is preferable that the said alkenyl group does not have a fluorine atom, and it is more preferable that it does not have a halogen atom.
一般式（１１）において、２つのＲ１０１は同一であることが好ましく、一般式（１２）において、２つのＲ１０２は同一であることが好ましい。 In the general formula (11), two R 101 are preferably the same, and in the general formula (12), the two R 102 are preferably the same.
化合物（１）の具体例としては、下記式で示される化合物等が挙げられる。
Figure JPOXMLDOC01-appb-C000011
 Specific examples of the compound (1) include compounds represented by the following formulae.
Figure JPOXMLDOC01-appb-C000011
化合物（１）としては、なかでも、
Figure JPOXMLDOC01-appb-C000012
 が好ましい。 Especially as a compound (1),
Figure JPOXMLDOC01-appb-C000012
 Is preferred.
化合物（１１）としては、例えば、
Figure JPOXMLDOC01-appb-C000013
 が好ましい。 As the compound (11), for example,
Figure JPOXMLDOC01-appb-C000013
 Is preferred.
化合物（１２）としては、例えば、
Figure JPOXMLDOC01-appb-C000014
 が好ましい。 As the compound (12), for example,
Figure JPOXMLDOC01-appb-C000014
 Is preferred.
化合物（１）、（１１）及び（１２）は、それぞれ、１種を単独で用いてもよく、２種以上を併用してもよい。 The compounds (1), (11) and (12) may be used alone or in combination of two or more.
本発明の電解液は、電解液に対し、化合物（１）を０．００１～２０質量％含むことが好ましい。化合物（１）の含有量が上記範囲内にあると、電気化学デバイスの高温保存特性やサイクル特性を一層向上させることができる。化合物（１）の含有量としては、０．００５質量％以上がより好ましく、０．０１質量％以上が更に好ましく、０．１質量％以上が更により好ましく、０．５質量％以上が特に好ましい。また、１５質量％以下がより好ましく、１０質量％以下が更に好ましく、７．０質量％以下が更により好ましく、５．０質量％以下が特に好ましい。 The electrolytic solution of the present invention preferably contains 0.001 to 20% by mass of the compound (1) with respect to the electrolytic solution. When the content of the compound (1) is in the above range, the high temperature storage characteristics and the cycle characteristics of the electrochemical device can be further improved. As content of a compound (1), 0.005 mass% or more is more preferable, 0.01 mass% or more is further more preferable, 0.1 mass% or more is still more preferable, 0.5 mass% or more is especially preferable . Moreover, 15 mass% or less is more preferable, 10 mass% or less is more preferable, 7.0 mass% or less is still more preferable, 5.0 mass% or less is especially preferable.
本発明の電解液が化合物（１１）を含む場合、化合物（１１）の含有量は、電解液に対し、０．００１～１５００質量ｐｐｍであることが好ましい。化合物（１１）の含有量が上記範囲内にあると、電気化学デバイスの高温保存特性やサイクル特性を一層向上させることができる。化合物（１１）の含有量としては、０．００５質量ｐｐｍ以上がより好ましく、０．０１質量ｐｐｍ以上が更に好ましく、１．０質量ｐｐｍ以上が特に好ましい。また、１０００質量ｐｐｍ以下がより好ましく、５００質量ｐｐｍ以下が更に好ましく、１００質量ｐｐｍ以下が特に好ましい。 When the electrolytic solution of the present invention contains the compound (11), the content of the compound (11) is preferably 0.001 to 1500 mass ppm with respect to the electrolytic solution. When the content of the compound (11) is in the above range, the high temperature storage characteristics and the cycle characteristics of the electrochemical device can be further improved. As content of a compound (11), 0.005 mass ppm or more is more preferable, 0.01 mass ppm or more is still more preferable, 1.0 mass ppm or more is especially preferable. Moreover, 1000 mass ppm or less is more preferable, 500 mass ppm or less is still more preferable, and 100 mass ppm or less is especially preferable.
本発明の電解液が化合物（１２）を含む場合、化合物（１２）の含有量は、電解液に対し、０．００１～１５００質量ｐｐｍであることが好ましい。化合物（１２）の含有量が上記範囲内にあると、電気化学デバイスの高温保存特性やサイクル特性を一層向上させることができる。化合物（１２）の含有量としては、０．００２質量ｐｐｍ以上がより好ましく、０．０１質量ｐｐｍ以上が更に好ましく、１．０質量ｐｐｍ以上が更により好ましい。また、１０００質量ｐｐｍ以下がより好ましく、５００質量ｐｐｍ以下が更に好ましく、１００質量ｐｐｍ以下が特に好ましい。 When the electrolytic solution of the present invention contains the compound (12), the content of the compound (12) is preferably 0.001 to 1500 mass ppm with respect to the electrolytic solution. When the content of the compound (12) is in the above range, the high temperature storage characteristics and cycle characteristics of the electrochemical device can be further improved. As content of a compound (12), 0.002 mass ppm or more is more preferable, 0.01 mass ppm or more is still more preferable, 1.0 mass ppm or more is still more preferable. Moreover, 1000 mass ppm or less is more preferable, 500 mass ppm or less is still more preferable, and 100 mass ppm or less is especially preferable.
本発明の電解液は、化合物（１１）及び（１２）の両方を含むことが好ましい。 The electrolytic solution of the present invention preferably contains both the compounds (11) and (12).
本発明の電解液は、更に、下記一般式（１３）：
Figure JPOXMLDOC01-appb-C000015
 （式中、Ｒ１０１は炭素数１～４のアルキル基であり、Ｒ１０２は炭素数２～４のアルケニル基である。）で表される化合物（１３）を含んでもよい。上記電解液が化合物（１３）を含むことにより、電気化学デバイスの高温保存特性やサイクル特性を一層向上させることができる。 The electrolytic solution of the present invention is further characterized by the following general formula (13):
Figure JPOXMLDOC01-appb-C000015
 (Wherein, R 101 is an alkyl group having 1 to 4 carbon atoms, and R 102 is an alkenyl group having 2 to 4 carbon atoms.) The compound (13) may be included. When the electrolytic solution contains the compound (13), high temperature storage characteristics and cycle characteristics of the electrochemical device can be further improved.
Ｒ１０１及びＲ１０２については、上述したとおりである。 R 101 and R 102 are as described above.
化合物（１３）の具体例としては、下記式で示される化合物等が挙げられる。
Figure JPOXMLDOC01-appb-C000016
 As a specific example of a compound (13), the compound etc. which are shown by a following formula are mentioned.
Figure JPOXMLDOC01-appb-C000016
化合物（１３）としては、なかでも、
Figure JPOXMLDOC01-appb-C000017
 が好ましい。 Among the compounds (13),
Figure JPOXMLDOC01-appb-C000017
 Is preferred.
化合物（１３）は、１種を単独で用いてもよく、２種以上を併用してもよい。 As the compound (13), one type may be used alone, or two or more types may be used in combination.
本発明の電解液が化合物（１３）を含む場合、化合物（１３）の含有量は、電解液に対し、０．００１～１００質量ｐｐｍであることが好ましい。化合物（１３）の含有量が上記範囲内にあると、電気化学デバイスの高温保存特性やサイクル特性を一層向上させることができる。化合物（１３）の含有量としては、０．０１質量ｐｐｍ以上がより好ましく、０．１質量ｐｐｍ以上が更に好ましく、０．５質量ｐｐｍ以上が特に好ましい。また、５０質量ｐｐｍ以下がより好ましく、３０質量ｐｐｍ以下が更に好ましく、１０質量ｐｐｍ以下が更により好ましい。 When the electrolytic solution of the present invention contains the compound (13), the content of the compound (13) is preferably 0.001 to 100 mass ppm with respect to the electrolytic solution. When the content of the compound (13) is in the above range, the high temperature storage characteristics and the cycle characteristics of the electrochemical device can be further improved. As content of a compound (13), 0.01 mass ppm or more is more preferable, 0.1 mass ppm or more is still more preferable, 0.5 mass ppm or more is especially preferable. Moreover, 50 mass ppm or less is more preferable, 30 mass ppm or less is still more preferable, and 10 mass ppm or less is still more preferable.
本発明の電解液は、溶媒（但し、化合物（１）及び（１１）～（１３）を除く）を含むことが好ましい。 The electrolytic solution of the present invention preferably contains a solvent (excluding compounds (1) and (11) to (13)).
上記溶媒は、カーボネート及びカルボン酸エステルからなる群より選択される少なくとも１種を含むことが好ましい。 The solvent preferably contains at least one selected from the group consisting of carbonate and carboxylic acid ester.
上記カーボネートは、環状カーボネートであってもよいし、鎖状カーボネートであってもよい。 The carbonate may be a cyclic carbonate or a linear carbonate.
上記環状カーボネートは、非フッ素化環状カーボネートであってもよいし、フッ素化環状カーボネートであってもよい。 The cyclic carbonate may be a non-fluorinated cyclic carbonate or a fluorinated cyclic carbonate.
上記非フッ素化環状カーボネートとしては、非フッ素化飽和環状カーボネートが挙げられ、炭素数２～６のアルキレン基を有する非フッ素化飽和アルキレンカーボネートが好ましく、炭素数２～４のアルキレン基を有する非フッ素化飽和アルキレンカーボネートがより好ましい。 Examples of the non-fluorinated cyclic carbonates include non-fluorinated saturated cyclic carbonates. Non-fluorinated saturated alkylene carbonates having an alkylene group of 2 to 6 carbon atoms are preferable, and non-fluorinated compounds having an alkylene group of 2 to 4 carbon atoms Saturated alkylene carbonate is more preferred.
なかでも、上記非フッ素化飽和環状カーボネートとしては、誘電率が高く、粘度が好適となる点で、エチレンカーボネート、プロピレンカーボネート、シス－２，３－ペンチレンカーボネート、シス－２，３－ブチレンカーボネート、２，３－ペンチレンカーボネート、２，３－ブチレンカーボネート、１，２－ペンチレンカーボネート、１，２－ブチレンカーボネート及びブチレンカーボネートからなる群より選択される少なくとも１種が好ましい。 Among them, ethylene carbonate, propylene carbonate, cis-2,3-pentylene carbonate, cis-2,3-butylene carbonate are preferred as the above non-fluorinated saturated cyclic carbonate in that the dielectric constant is high and the viscosity is suitable. Preferred is at least one selected from the group consisting of 2,3-pentylene carbonate, 2,3-butylene carbonate, 1,2-pentylene carbonate, 1,2-butylene carbonate and butylene carbonate.
上記非フッ素化飽和環状カーボネートは、１種を単独で用いてもよく、２種以上を任意の組み合わせ及び比率で併用してもよい。 The said non-fluorinated saturated cyclic carbonate may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.
上記非フッ素化飽和環状カーボネートが含まれる場合、上記非フッ素化飽和環状カーボネートの含有量は、上記溶媒に対して５～９０体積％であることが好ましく、１０～６０体積％であることがより好ましく、１５～４５体積％であることが更に好ましい。 When the non-fluorinated saturated cyclic carbonate is contained, the content of the non-fluorinated saturated cyclic carbonate is preferably 5 to 90% by volume, more preferably 10 to 60% by volume, with respect to the solvent. Preferably, it is 15 to 45% by volume.
上記フッ素化環状カーボネートは、フッ素原子を有する環状カーボネートである。フッ素化環状カーボネートを含む溶媒は、高電圧下でも好適に使用することができる。
なお、本明細書において「高電圧」とは、４．２Ｖ以上の電圧をいう。また、「高電圧」の上限は４．９Ｖが好ましい。 The fluorinated cyclic carbonate is a cyclic carbonate having a fluorine atom. The solvent containing fluorinated cyclic carbonate can be suitably used even under high voltage.
In the present specification, “high voltage” refers to a voltage of 4.2 V or more. Moreover, as for the upper limit of "high voltage", 4.9 V is preferable.
上記フッ素化環状カーボネートは、フッ素化飽和環状カーボネートであってもよいし、フッ素化不飽和環状カーボネートであってもよい。 The fluorinated cyclic carbonate may be a fluorinated saturated cyclic carbonate or a fluorinated unsaturated cyclic carbonate.
上記フッ素化飽和環状カーボネートは、フッ素原子を有する飽和環状カーボネートであり、具体的には、下記一般式（Ａ）： The fluorinated saturated cyclic carbonate is a saturated cyclic carbonate having a fluorine atom, and specifically, the following general formula (A):
Figure JPOXMLDOC01-appb-C000018
 （式中、Ｘ１～Ｘ４は同じか又は異なり、それぞれ－Ｈ、－ＣＨ３、－Ｃ２Ｈ５、－Ｆ、エーテル結合を有してもよいフッ素化アルキル基、又は、エーテル結合を有してもよいフッ素化アルコキシ基を表す。ただし、Ｘ１～Ｘ４の少なくとも１つは、－Ｆ、エーテル結合を有してもよいフッ素化アルキル基、又は、エーテル結合を有してもよいフッ素化アルコキシ基である。）で示される化合物が挙げられる。上記フッ素化アルキル基とは、－ＣＦ３、－ＣＦ２Ｈ、－ＣＨ２Ｆ等である。
Figure JPOXMLDOC01-appb-C000018
 (Wherein, X 1 to X 4 are the same or different and each is —H, —CH 3 , —C 2 H 5 , —F, a fluorinated alkyl group which may have an ether bond, or an ether bond A fluorinated alkoxy group which may be substituted, provided that at least one of X 1 to X 4 is —F, a fluorinated alkyl group which may have an ether bond, or an ether bond; And a compound represented by the above formula) is a good fluorinated alkoxy group. The fluorinated alkyl group is —CF 3 , —CF 2 H, —CH 2 F or the like.
上記フッ素化飽和環状カーボネートを含むと、本発明の電解液を高電圧リチウムイオン二次電池等に適用した場合電解液の耐酸化性が向上し、安定で優れた充放電特性が得られる。
なお、本明細書中で「エーテル結合」は、－Ｏ－で表される結合である。 When the above-mentioned fluorinated saturated cyclic carbonate is contained, when the electrolytic solution of the present invention is applied to a high voltage lithium ion secondary battery etc., the oxidation resistance of the electrolytic solution is improved, and stable and excellent charge / discharge characteristics can be obtained.
In the present specification, “ether bond” is a bond represented by —O—.
誘電率、耐酸化性が良好な点から、Ｘ１～Ｘ４の１つ又は２つが、－Ｆ、エーテル結合を有してもよいフッ素化アルキル基、又は、エーテル結合を有してもよいフッ素化アルコキシ基であることが好ましい。 From the viewpoint of good dielectric constant and oxidation resistance, one or two of X 1 to X 4 may have -F, a fluorinated alkyl group which may have an ether bond, or an ether bond It is preferable that it is a fluorinated alkoxy group.
低温での粘性の低下、引火点の上昇、更には電解質塩の溶解性の向上が期待できることから、Ｘ１～Ｘ４は、－Ｈ、－Ｆ、フッ素化アルキル基（ａ）、エーテル結合を有するフッ素化アルキル基（ｂ）、又は、フッ素化アルコキシ基（ｃ）であることが好ましい。 X 1 to X 4 are —H, −F, a fluorinated alkyl group (a), an ether bond, because a decrease in viscosity at low temperatures, an increase in flash point, and an increase in solubility of electrolyte salts can be expected. It is preferable that it is a fluorinated alkyl group (b) or a fluorinated alkoxy group (c).
上記フッ素化アルキル基（ａ）は、アルキル基が有する水素原子の少なくとも１つをフッ素原子で置換したものである。フッ素化アルキル基（ａ）の炭素数は、１～２０が好ましく、１～１７がより好ましく、１～７が更に好ましく、１～５が特に好ましい。
炭素数が大きくなりすぎると低温特性が低下したり、電解質塩の溶解性が低下したりするおそれがあり、炭素数が少な過ぎると、電解質塩の溶解性の低下、放電効率の低下、更には粘性の増大等がみられることがある。 The said fluorinated alkyl group (a) is what substituted at least 1 of the hydrogen atom which an alkyl group has with a fluorine atom. The carbon number of the fluorinated alkyl group (a) is preferably 1 to 20, more preferably 1 to 17, still more preferably 1 to 7, and particularly preferably 1 to 5.
If the number of carbons is too large, the low temperature characteristics may deteriorate or the solubility of the electrolyte salt may decrease. If the number of carbons is too small, the solubility of the electrolyte salt may decrease, the discharge efficiency may decrease, and further An increase in viscosity etc. may be observed.
上記フッ素化アルキル基（ａ）のうち、炭素数が１のものとしては、ＣＦＨ２－、ＣＦ２Ｈ－、ＣＦ３－が挙げられる。特に、ＣＦ２Ｈ－又はＣＦ３－が高温保存特性上好ましく、ＣＦ３－が最も好ましい。 Among the above-mentioned fluorinated alkyl groups (a), one having 1 carbon atom includes CFH 2- , CF 2 H-and CF 3- . In particular, CF 2 H— or CF 3 — is preferable in view of high-temperature storage characteristics, and CF 3 — is most preferable.
上記フッ素化アルキル基（ａ）のうち、炭素数が２以上のものとしては、下記一般式（ａ－１）：
Ｒ１－Ｒ２－　（ａ－１）
（式中、Ｒ１はフッ素原子を有していてもよい炭素数１以上のアルキル基；Ｒ２はフッ素原子を有していてもよい炭素数１～３のアルキレン基；ただし、Ｒ１及びＲ２の少なくとも一方はフッ素原子を有している）で示されるフッ素化アルキル基が、電解質塩の溶解性が良好な点から好ましく例示できる。
なお、Ｒ１及びＲ２は、更に、炭素原子、水素原子及びフッ素原子以外の、その他の原子を有していてもよい。 Among the above-mentioned fluorinated alkyl groups (a), those having 2 or more carbon atoms include those represented by the following general formula (a-1):
R 1 -R 2- (a-1)
(Wherein, R 1 is an alkyl group having 1 or more carbon atoms which may have a fluorine atom; R 2 is an alkylene group having 1 to 3 carbon atoms which may have a fluorine atom; however, R 1 and The fluorinated alkyl group represented by at least one of R 2 s having a fluorine atom can be preferably exemplified from the viewpoint of good solubility of the electrolyte salt.
R 1 and R 2 may further have other atoms than carbon atoms, hydrogen atoms and fluorine atoms.
Ｒ１は、フッ素原子を有していてもよい炭素数１以上のアルキル基である。Ｒ１としては、炭素数１～１６の直鎖状又は分岐鎖状のアルキル基が好ましい。Ｒ１の炭素数としては、１～６がより好ましく、１～３が更に好ましい。 R 1 is an alkyl group having one or more carbon atoms which may have a fluorine atom. As R 1 , a linear or branched alkyl group having 1 to 16 carbon atoms is preferable. The number of carbon atoms of R 1 is more preferably 1 to 6, and still more preferably 1 to 3.
Ｒ１として、具体的には、直鎖状又は分岐鎖状のアルキル基として、ＣＨ３－、ＣＨ３ＣＨ２－、ＣＨ３ＣＨ２ＣＨ２－、ＣＨ３ＣＨ２ＣＨ２ＣＨ２－、 As R 1 , specifically, as a linear or branched alkyl group, CH 3- , CH 3 CH 2- , CH 3 CH 2 CH 2- , CH 3 CH 2 CH 2 CH 2- ,
Figure JPOXMLDOC01-appb-C000019
Figure JPOXMLDOC01-appb-C000019
等が挙げられる。 Etc.
また、Ｒ１がフッ素原子を有する直鎖状のアルキル基である場合、ＣＦ３－、ＣＦ３ＣＨ２－、ＣＦ３ＣＦ２－、ＣＦ３ＣＨ２ＣＨ２－、ＣＦ３ＣＦ２ＣＨ２－、ＣＦ３ＣＦ２ＣＦ２－、ＣＦ３ＣＨ２ＣＦ２－、ＣＦ３ＣＨ２ＣＨ２ＣＨ２－、ＣＦ３ＣＦ２ＣＨ２ＣＨ２－、ＣＦ３ＣＨ２ＣＦ２ＣＨ２－、ＣＦ３ＣＦ２ＣＦ２ＣＨ２－、ＣＦ３ＣＦ２ＣＦ２ＣＦ２－、ＣＦ３ＣＦ２ＣＨ２ＣＦ２－、ＣＦ３ＣＨ２ＣＨ２ＣＨ２ＣＨ２－、ＣＦ３ＣＦ２ＣＨ２ＣＨ２ＣＨ２－、ＣＦ３ＣＨ２ＣＦ２ＣＨ２ＣＨ２－、ＣＦ３ＣＦ２ＣＦ２ＣＨ２ＣＨ２－、ＣＦ３ＣＦ２ＣＦ２ＣＦ２ＣＨ２－、ＣＦ３ＣＦ２ＣＨ２ＣＦ２ＣＨ２－、ＣＦ３ＣＦ２ＣＨ２ＣＨ２ＣＨ２ＣＨ２－、ＣＦ３ＣＦ２ＣＦ２ＣＦ２ＣＨ２ＣＨ２－、ＣＦ３ＣＦ２ＣＨ２ＣＦ２ＣＨ２ＣＨ２－、ＨＣＦ２－、ＨＣＦ２ＣＨ２－、ＨＣＦ２ＣＦ２－、ＨＣＦ２ＣＨ２ＣＨ２－、ＨＣＦ２ＣＦ２ＣＨ２－、ＨＣＦ２ＣＨ２ＣＦ２－、ＨＣＦ２ＣＦ２ＣＨ２ＣＨ２－、ＨＣＦ２ＣＨ２ＣＦ２ＣＨ２－、ＨＣＦ２ＣＦ２ＣＦ２ＣＦ２－、ＨＣＦ２ＣＦ２ＣＨ２ＣＨ２ＣＨ２－、ＨＣＦ２ＣＨ２ＣＦ２ＣＨ２ＣＨ２－、ＨＣＦ２ＣＦ２ＣＦ２ＣＦ２ＣＨ２－、ＨＣＦ２ＣＦ２ＣＦ２ＣＦ２ＣＨ２ＣＨ２－、ＦＣＨ２－、ＦＣＨ２ＣＨ２－、ＦＣＨ２ＣＦ２－、ＦＣＨ２ＣＦ２ＣＨ２－、ＦＣＨ２ＣＦ２ＣＦ２－、ＣＨ３ＣＦ２ＣＨ２－、ＣＨ３ＣＦ２ＣＦ２－、ＣＨ３ＣＦ２ＣＨ２ＣＦ２－、ＣＨ３ＣＦ２ＣＦ２ＣＦ２－、ＣＨ３ＣＨ２ＣＦ２ＣＦ２－、ＣＨ３ＣＦ２ＣＨ２ＣＦ２ＣＨ２－、ＣＨ３ＣＦ２ＣＦ２ＣＦ２ＣＨ２－、ＣＨ３ＣＦ２ＣＦ２ＣＨ２ＣＨ２－、ＣＨ３ＣＨ２ＣＦ２ＣＦ２ＣＨ２－、ＣＨ３ＣＦ２ＣＨ２ＣＦ２ＣＨ２ＣＨ２－、ＣＨ３ＣＦ２ＣＨ２ＣＦ２ＣＨ２ＣＨ２－、ＨＣＦＣｌＣＦ２ＣＨ２－、ＨＣＦ２ＣＦＣｌＣＨ２－、ＨＣＦ２ＣＦＣｌＣＦ２ＣＦＣｌＣＨ２－、ＨＣＦＣｌＣＦ２ＣＦＣｌＣＦ２ＣＨ２－等が挙げられる。 Moreover, when R 1 is a linear alkyl group having a fluorine atom, CF 3- , CF 3 CH 2- , CF 3 CF 2- , CF 3 CH 2 CH 2- , CF 3 CF 2 CH 2- , CF 3 CF 2 CF 2 - , CF 3 CH 2 CF 2 -, CF 3 CH 2 CH 2 CH 2 -, CF 3 CF 2 CH 2 CH 2 -, CF 3 CH 2 CF 2 CH 2 -, CF 3 CF 2 CF 2 CH 2- , CF 3 CF 2 CF 2 CF 2- , CF 3 CF 2 CH 2 CF 2- , CF 3 CH 2 CH 2 CH 2 CH 2- , CF 3 CF 2 CH 2 CH 2 CH 2- , CF 3 CH 2 CF 2 CH 2 CH 2 -, CF 3 CF 2 CF 2 CH 2 CH 2 -, CF 3 CF 2 CF 2 CF 2 CH 2 -, CF 3 CF 2 CH 2 CF 2 CH 2 -, CF 3 C F 2 CH 2 CH 2 CH 2 CH 2 -, CF 3 CF 2 CF 2 CF 2 CH 2 CH 2 -, CF 3 CF 2 CH 2 CF 2 CH 2 CH 2 -, HCF 2 -, HCF 2 CH 2 -, HCF 2 CF 2 -, HCF 2 CH 2 CH 2 -, HCF 2 CF 2 CH 2 -, HCF 2 CH 2 CF 2 -, HCF 2 CF 2 CH 2 CH 2 -, HCF 2 CH 2 CF 2 CH 2 -, HCF 2 CF 2 CF 2 CF 2- , HCF 2 CF 2 CH 2 CH 2 CH 2- , HCF 2 CH 2 CF 2 CH 2 CH 2- , HCF 2 CF 2 CF 2 CF 2 CF 2 CH 2- , HCF 2 CF 2 CF 2 CF 2 CH 2 CH 2 -, FCH 2 -, FCH 2 CH 2 -, FCH 2 CF 2 -, FCH 2 CF 2 CH 2 -, FCH 2 CF 2 CF 2 - CH 3 CF 2 CH 2 -, CH 3 CF 2 CF 2 -, CH 3 CF 2 CH 2 CF 2 -, CH 3 CF 2 CF 2 CF 2 -, CH 3 CH 2 CF 2 CF 2 -, CH 3 CF 2 CH 2 CF 2 CH 2 -, CH 3 CF 2 CF 2 CF 2 CH 2 -, CH 3 CF 2 CF 2 CH 2 CH 2 -, CH 3 CH 2 CF 2 CF 2 CH 2 -, CH 3 CF 2 CH 2 CF 2 CH 2 CH 2 -, CH 3 CF 2 CH 2 CF 2 CH 2 CH 2 -, HCFClCF 2 CH 2 -, HCF 2 CFClCH 2 -, HCF 2 CFClCF 2 CFClCH 2 -, HCFClCF 2 CFClCF 2 CH 2 - , etc. Can be mentioned.
また、Ｒ１がフッ素原子を有する分岐鎖状のアルキル基である場合、 Moreover, when R 1 is a branched alkyl group having a fluorine atom,
Figure JPOXMLDOC01-appb-C000020
Figure JPOXMLDOC01-appb-C000020
Figure JPOXMLDOC01-appb-C000021
Figure JPOXMLDOC01-appb-C000021
等が好ましく挙げられる。ただし、ＣＨ３－やＣＦ３－という分岐を有していると粘性が高くなりやすいため、その数は少ない（１個）かゼロであることがより好ましい。 Etc. are preferably mentioned. However, since the viscosity is likely to be high when having a branch such as CH 3 -or CF 3- , it is more preferable that the number thereof is small (one) or zero.
Ｒ２はフッ素原子を有していてもよい炭素数１～３のアルキレン基である。Ｒ２は、直鎖状であってもよく、分岐鎖状であってもよい。このような直鎖状又は分岐鎖状のアルキレン基を構成する最小構造単位の一例を下記に示す。Ｒ２はこれらの単独又は組合せで構成される。 R 2 is an alkylene group having 1 to 3 carbon atoms which may have a fluorine atom. R 2 may be linear or branched. An example of the minimum structural unit which comprises such a linear or branched alkylene group is shown below. R 2 is composed of these alone or in combination.
（ｉ）直鎖状の最小構造単位：
－ＣＨ２－、－ＣＨＦ－、－ＣＦ２－、－ＣＨＣｌ－、－ＣＦＣｌ－、－ＣＣｌ２－ (I) Linear minimum structural unit:
-CH 2 -, - CHF -, - CF 2 -, - CHCl -, - CFCl -, - CCl 2 -
（ｉｉ）分岐鎖状の最小構造単位： (Ii) Branched minimum structural unit:
Figure JPOXMLDOC01-appb-C000022
Figure JPOXMLDOC01-appb-C000022
なお、以上の例示のなかでも、塩基による脱ＨＣｌ反応が起こらず、より安定なことから、Ｃｌを含有しない構成単位から構成されることが好ましい。 In addition, among the above exemplifications, it is preferable to be composed of a structural unit not containing Cl, because deHCl reaction with a base does not occur and it is more stable.
Ｒ２は、直鎖状である場合には、上述した直鎖状の最小構造単位のみからなるものであり、なかでも－ＣＨ２－、－ＣＨ２ＣＨ２－又は－ＣＦ２－が好ましい。電解質塩の溶解性をより一層向上させることができる点から、－ＣＨ２－又は－ＣＨ２ＣＨ２－がより好ましい。 When R 2 is linear, it consists only of the above-mentioned linear minimum structural unit, and in particular, —CH 2 —, —CH 2 CH 2 — or —CF 2 — is preferable. -CH 2 -or -CH 2 CH 2 -is more preferable because the solubility of the electrolyte salt can be further improved.
Ｒ２は、分岐鎖状である場合には、上述した分岐鎖状の最小構造単位を少なくとも１つ含んでなるものであり、一般式－（ＣＸａＸｂ）－（ＸａはＨ、Ｆ、ＣＨ３又はＣＦ３；ＸｂはＣＨ３又はＣＦ３。ただし、ＸｂがＣＦ３の場合、ＸａはＨ又はＣＨ３である）で表されるものが好ましく例示できる。これらは特に電解質塩の溶解性をより一層向上させることができる。 When R 2 is branched, it contains at least one of the branched minimum structural units described above, and has a general formula of-(CX a X b )-(X a is H, F , CH 3 or CF 3;. X b is CH 3 or CF 3 provided that when X b is CF 3, X a is one represented by H or CH 3) it can be preferably exemplified. In particular, these can further improve the solubility of the electrolyte salt.
好ましいフッ素化アルキル基（ａ）としては、例えばＣＦ３ＣＦ２－、ＨＣＦ２ＣＦ２－、Ｈ２ＣＦＣＦ２－、ＣＨ３ＣＦ２－、ＣＦ３ＣＨＦ－、ＣＨ３ＣＦ２－、ＣＦ３ＣＦ２ＣＦ２－、ＨＣＦ２ＣＦ２ＣＦ２－、Ｈ２ＣＦＣＦ２ＣＦ２－、ＣＨ３ＣＦ２ＣＦ２－、 Preferred fluorinated alkyl group (a), for example CF 3 CF 2 -, HCF 2 CF 2 -, H 2 CFCF 2 -, CH 3 CF 2 -, CF 3 CHF-, CH 3 CF 2 -, CF 3 CF 2 CF 2- , HCF 2 CF 2 CF 2- , H 2 CFCF 2 CF 2- , CH 3 CF 2 CF 2- ,
Figure JPOXMLDOC01-appb-C000023
Figure JPOXMLDOC01-appb-C000023
Figure JPOXMLDOC01-appb-C000024
Figure JPOXMLDOC01-appb-C000024
等が挙げられる。 Etc.
上記エーテル結合を有するフッ素化アルキル基（ｂ）は、エーテル結合を有するアルキル基が有する水素原子の少なくとも１つをフッ素原子で置換したものである。上記エーテル結合を有するフッ素化アルキル基（ｂ）は、炭素数が２～１７であることが好ましい。炭素数が多過ぎると、上記フッ素化飽和環状カーボネートの粘性が高くなり、また、フッ素含有基が多くなることから、誘電率の低下による電解質塩の溶解性低下や、他の溶剤との相溶性の低下がみられることがある。この観点から上記エーテル結合を有するフッ素化アルキル基（ｂ）の炭素数は２～１０がより好ましく、２～７が更に好ましい。 The fluorinated alkyl group (b) having an ether bond is one in which at least one of the hydrogen atoms of the alkyl group having an ether bond is substituted with a fluorine atom. The fluorinated alkyl group (b) having an ether bond preferably has 2 to 17 carbon atoms. If the number of carbon atoms is too large, the viscosity of the fluorinated saturated cyclic carbonate becomes high, and the number of fluorine-containing groups increases. Therefore, the solubility of the electrolyte salt is reduced due to the reduction of the dielectric constant, and the compatibility with other solvents May be seen. From this viewpoint, the carbon number of the fluorinated alkyl group (b) having an ether bond is more preferably 2 to 10, still more preferably 2 to 7.
上記エーテル結合を有するフッ素化アルキル基（ｂ）のエーテル部分を構成するアルキレン基は直鎖状又は分岐鎖状のアルキレン基でよい。そうした直鎖状又は分岐鎖状のアルキレン基を構成する最小構造単位の一例を下記に示す。 The alkylene group constituting the ether portion of the fluorinated alkyl group (b) having an ether bond may be a linear or branched alkylene group. Examples of the minimum structural unit constituting such a linear or branched alkylene group are shown below.
（ｉ）直鎖状の最小構造単位：
－ＣＨ２－、－ＣＨＦ－、－ＣＦ２－、－ＣＨＣｌ－、－ＣＦＣｌ－、－ＣＣｌ２－ (I) Linear minimum structural unit:
-CH 2 -, - CHF -, - CF 2 -, - CHCl -, - CFCl -, - CCl 2 -
（ｉｉ）分岐鎖状の最小構造単位： (Ii) Branched minimum structural unit:
Figure JPOXMLDOC01-appb-C000025
Figure JPOXMLDOC01-appb-C000025
アルキレン基は、これらの最小構造単位単独で構成されてもよく、直鎖状（ｉ）同士、分岐鎖状（ｉｉ）同士、又は、直鎖状（ｉ）と分岐鎖状（ｉｉ）との組み合わせにより構成されてもよい。好ましい具体例は、後述する。 The alkylene group may be composed of these minimum structural units alone, and linear (i), branched (ii) or linear (i) and branched (ii) It may be configured by a combination. Preferred specific examples will be described later.
なお、以上の例示のなかでも、塩基による脱ＨＣｌ反応が起こらず、より安定なことから、Ｃｌを含有しない構成単位から構成されることが好ましい。 In addition, among the above exemplifications, it is preferable to be composed of a structural unit not containing Cl, because deHCl reaction with a base does not occur and it is more stable.
更に好ましいエーテル結合を有するフッ素化アルキル基（ｂ）としては、一般式（ｂ－１）：
Ｒ３－（ＯＲ４）ｎ１－　　　　　　　（ｂ－１）
（式中、Ｒ３はフッ素原子を有していてもよい、好ましくは炭素数１～６のアルキル基；Ｒ４はフッ素原子を有していてもよい、好ましくは炭素数１～４のアルキレン基；ｎ１は１～３の整数；ただし、Ｒ３及びＲ４の少なくとも１つはフッ素原子を有している）で示されるものが挙げられる。 Further preferable examples of the fluorinated alkyl group (b) having an ether bond include general formula (b-1):
R 3- (OR 4 ) n 1-(b-1)
(Wherein, R 3 may have a fluorine atom, preferably an alkyl group having 1 to 6 carbon atoms; R 4 may have a fluorine atom, preferably an alkylene having 1 to 4 carbon atoms And n1 is an integer of 1 to 3, provided that at least one of R 3 and R 4 has a fluorine atom.
Ｒ３及びＲ４としては以下のものが例示でき、これらを適宜組み合わせて、上記一般式（ｂ－１）で表されるエーテル結合を有するフッ素化アルキル基（ｂ）を構成することができるが、これらのみに限定されるものではない。 Examples of R 3 and R 4 include the following, which can be combined as appropriate to form a fluorinated alkyl group (b) having an ether bond represented by the above general formula (b-1). Not limited to these.
（１）Ｒ３としては、一般式：Ｘｃ ３Ｃ－（Ｒ５）ｎ２－（３つのＸｃは同じか又は異なりいずれもＨ又はＦ；Ｒ５は炭素数１～５のフッ素原子を有していてもよいアルキレン基；ｎ２は０又は１）で表されるアルキル基が好ましい。 (1) As R 3 , a general formula: X c 3 C- (R 5 ) n 2- (wherein three X c are the same or different, each is H or F; R 5 is a C 1-5 fluorine atom Alkylene group which may be possessed; n2 is preferably an alkyl group represented by 0 or 1).
ｎ２が０の場合、Ｒ３としては、ＣＨ３－、ＣＦ３－、ＨＣＦ２－及びＨ２ＣＦ－が挙げられる。 When n2 is 0, R 3 includes CH 3- , CF 3- , HCF 2 -and H 2 CF-.
ｎ２が１の場合の具体例としては、Ｒ３が直鎖状のものとして、ＣＦ３ＣＨ２－、ＣＦ３ＣＦ２－、ＣＦ３ＣＨ２ＣＨ２－、ＣＦ３ＣＦ２ＣＨ２－、ＣＦ３ＣＦ２ＣＦ２－、ＣＦ３ＣＨ２ＣＦ２－、ＣＦ３ＣＨ２ＣＨ２ＣＨ２－、ＣＦ３ＣＦ２ＣＨ２ＣＨ２－、ＣＦ３ＣＨ２ＣＦ２ＣＨ２－、ＣＦ３ＣＦ２ＣＦ２ＣＨ２－、ＣＦ３ＣＦ２ＣＦ２ＣＦ２－、ＣＦ３ＣＦ２ＣＨ２ＣＦ２－、ＣＦ３ＣＨ２ＣＨ２ＣＨ２ＣＨ２－、ＣＦ３ＣＦ２ＣＨ２ＣＨ２ＣＨ２－、ＣＦ３ＣＨ２ＣＦ２ＣＨ２ＣＨ２－、ＣＦ３ＣＦ２ＣＦ２ＣＨ２ＣＨ２－、ＣＦ３ＣＦ２ＣＦ２ＣＦ２ＣＨ２－、ＣＦ３ＣＦ２ＣＨ２ＣＦ２ＣＨ２－、ＣＦ３ＣＦ２ＣＨ２ＣＨ２ＣＨ２ＣＨ２－、ＣＦ３ＣＦ２ＣＦ２ＣＦ２ＣＨ２ＣＨ２－、ＣＦ３ＣＦ２ＣＨ２ＣＦ２ＣＨ２ＣＨ２－、ＨＣＦ２ＣＨ２－、ＨＣＦ２ＣＦ２－、ＨＣＦ２ＣＨ２ＣＨ２－、ＨＣＦ２ＣＦ２ＣＨ２－、ＨＣＦ２ＣＨ２ＣＦ２－、ＨＣＦ２ＣＦ２ＣＨ２ＣＨ２－、ＨＣＦ２ＣＨ２ＣＦ２ＣＨ２－、ＨＣＦ２ＣＦ２ＣＦ２ＣＦ２－、ＨＣＦ２ＣＦ２ＣＨ２ＣＨ２ＣＨ２－、ＨＣＦ２ＣＨ２ＣＦ２ＣＨ２ＣＨ２－、ＨＣＦ２ＣＦ２ＣＦ２ＣＦ２ＣＨ２－、ＨＣＦ２ＣＦ２ＣＦ２ＣＦ２ＣＨ２ＣＨ２－、ＦＣＨ２ＣＨ２－、ＦＣＨ２ＣＦ２－、ＦＣＨ２ＣＦ２ＣＨ２－、ＣＨ３ＣＦ２－、ＣＨ３ＣＨ２－、ＣＨ３ＣＦ２ＣＨ２－、ＣＨ３ＣＦ２ＣＦ２－、ＣＨ３ＣＨ２ＣＨ２－、ＣＨ３ＣＦ２ＣＨ２ＣＦ２－、ＣＨ３ＣＦ２ＣＦ２ＣＦ２－、ＣＨ３ＣＨ２ＣＦ２ＣＦ２－、ＣＨ３ＣＨ２ＣＨ２ＣＨ２－、ＣＨ３ＣＦ２ＣＨ２ＣＦ２ＣＨ２－、ＣＨ３ＣＦ２ＣＦ２ＣＦ２ＣＨ２－、ＣＨ３ＣＦ２ＣＦ２ＣＨ２ＣＨ２－、ＣＨ３ＣＨ２ＣＦ２ＣＦ２ＣＨ２－、ＣＨ３ＣＦ２ＣＨ２ＣＦ２ＣＨ２ＣＨ２－、ＣＨ３ＣＨ２ＣＦ２ＣＦ２ＣＨ２ＣＨ２－、ＣＨ３ＣＦ２ＣＨ２ＣＦ２ＣＨ２ＣＨ２－等が例示できる。 As a specific example when n2 is 1, as R 3 is linear, CF 3 CH 2- , CF 3 CF 2- , CF 3 CH 2 CH 2- , CF 3 CF 2 CH 2- , CF 3 CF 2 CF 2 -, CF 3 CH 2 CF 2 -, CF 3 CH 2 CH 2 CH 2 -, CF 3 CF 2 CH 2 CH 2 -, CF 3 CH 2 CF 2 CH 2 -, CF 3 CF 2 CF 2 CH 2- , CF 3 CF 2 CF 2 CF 2- , CF 3 CF 2 CH 2 CF 2- , CF 3 CH 2 CH 2 CH 2 CH 2- , CF 3 CF 2 CH 2 CH 2 CH 2- , CF 3 CH 2 CF 2 CH 2 CH 2 -, CF 3 CF 2 CF 2 CH 2 CH 2 -, CF 3 CF 2 CF 2 CF 2 CH 2 -, CF 3 CF 2 CH 2 CF 2 CH 2 -, CF 3 CF 2 CH 2 H 2 CH 2 CH 2 -, CF 3 CF 2 CF 2 CF 2 CH 2 CH 2 -, CF 3 CF 2 CH 2 CF 2 CH 2 CH 2 -, HCF 2 CH 2 -, HCF 2 CF 2 -, HCF 2 CH 2 CH 2 -, HCF 2 CF 2 CH 2 -, HCF 2 CH 2 CF 2 -, HCF 2 CF 2 CH 2 CH 2 -, HCF 2 CH 2 CF 2 CH 2 -, HCF 2 CF 2 CF 2 CF 2 -, HCF 2 CF 2 CH 2 CH 2 CH 2- , HCF 2 CH 2 CF 2 CH 2 CH 2- , HCF 2 CF 2 CF 2 CF 2 CH 2- , HCF 2 CF 2 CF 2 CF 2 CF 2 CH 2 CH 2 -, FCH 2 CH 2 -, FCH 2 CF 2 -, FCH 2 CF 2 CH 2 -, CH 3 CF 2 -, CH 3 CH 2 -, CH 3 CF 2 CH 2 -, C 3 CF 2 CF 2 -, CH 3 CH 2 CH 2 -, CH 3 CF 2 CH 2 CF 2 -, CH 3 CF 2 CF 2 CF 2 -, CH 3 CH 2 CF 2 CF 2 -, CH 3 CH 2 CH 2 CH 2- , CH 3 CF 2 CH 2 CF 2 CH 2- , CH 3 CF 2 CF 2 CF 2 CH 2- , CH 3 CF 2 CF 2 CH 2 CH 2- , CH 3 CH 2 CF 2 CF 2 CH 2— , CH 3 CF 2 CH 2 CF 2 CH 2 CH 2 —, CH 3 CH 2 CF 2 CF 2 CF 2 CH 2 CH 2 —, CH 3 CF 2 CH 2 CF 2 CH 2 CH 2 — and the like.
ｎ２が１であり、かつＲ３が分岐鎖状のものとしては、 When n2 is 1 and R 3 is a branched chain,
Figure JPOXMLDOC01-appb-C000026
Figure JPOXMLDOC01-appb-C000026
等が挙げられる。 Etc.
ただし、ＣＨ３－やＣＦ３－という分岐を有していると粘性が高くなりやすいため、Ｒ３が直鎖状のものがより好ましい。 However, since the viscosity tends to be high when having a branch such as CH 3 -or CF 3- , it is more preferable that R 3 is linear.
（２）上記一般式（ｂ－１）の－（ＯＲ４）ｎ１－において、ｎ１は１～３の整数であり、好ましくは１又は２である。なお、ｎ１＝２又は３のとき、Ｒ４は同じでも異なっていてもよい。 (2) In- (OR 4 ) n1 -of the above general formula (b-1), n1 is an integer of 1 to 3, preferably 1 or 2. When n1 = 2 or 3, R 4 may be the same or different.
Ｒ４の好ましい具体例としては、次の直鎖状又は分岐鎖状のものが例示できる。 As preferable specific examples of R 4 , the following linear or branched ones can be exemplified.
直鎖状のものとしては、－ＣＨ２－、－ＣＨＦ－、－ＣＦ２－、－ＣＨ２ＣＨ２－、－ＣＦ２ＣＨ２－、－ＣＦ２ＣＦ２－、－ＣＨ２ＣＦ２－、－ＣＨ２ＣＨ２ＣＨ２－、－ＣＨ２ＣＨ２ＣＦ２－、－ＣＨ２ＣＦ２ＣＨ２－、－ＣＨ２ＣＦ２ＣＦ２－、－ＣＦ２ＣＨ２ＣＨ２－、－ＣＦ２ＣＦ２ＣＨ２－、－ＣＦ２ＣＨ２ＣＦ２－、－ＣＦ２ＣＦ２ＣＦ２－等が例示できる。 As those linear, -CH 2 -, - CHF - , - CF 2 -, - CH 2 CH 2 -, - CF 2 CH 2 -, - CF 2 CF 2 -, - CH 2 CF 2 -, -CH 2 CH 2 CH 2- , -CH 2 CH 2 CF 2- , -CH 2 CF 2 CH 2- , -CH 2 CF 2 CF 2- , -CF 2 CH 2 CH 2- , -CF 2 CF 2 CH 2- , -CF 2 CH 2 CF 2- , -CF 2 CF 2 CF 2- and the like can be exemplified.
分岐鎖状のものとしては、 As branched ones,
Figure JPOXMLDOC01-appb-C000027
Figure JPOXMLDOC01-appb-C000027
等が挙げられる。 Etc.
上記フッ素化アルコキシ基（ｃ）は、アルコキシ基が有する水素原子の少なくとも１つをフッ素原子で置換したものである。上記フッ素化アルコキシ基（ｃ）は、炭素数が１～１７であることが好ましい。より好ましくは、炭素数１～６である。 The said fluorinated alkoxy group (c) substitutes at least one of the hydrogen atoms which an alkoxy group has with a fluorine atom. The fluorinated alkoxy group (c) preferably has 1 to 17 carbon atoms. More preferably, it has 1 to 6 carbon atoms.
上記フッ素化アルコキシ基（ｃ）としては、一般式：Ｘｄ ３Ｃ－（Ｒ６）ｎ３－Ｏ－（３つのＸｄは同じか又は異なりいずれもＨ又はＦ；Ｒ６は好ましくは炭素数１～５のフッ素原子を有していてもよいアルキレン基；ｎ３は０又は１；ただし３つのＸｄのいずれかはフッ素原子を含んでいる）で表されるフッ素化アルコキシ基が特に好ましい。 The fluorinated alkoxy group (c) may be represented by the general formula: X d 3 C- (R 6 ) n 3 -O- (wherein three X d are the same or different and each is H or F; R 6 preferably has carbon atoms Particularly preferred is a fluorinated alkoxy group represented by an alkylene group which may have 1 to 5 fluorine atoms; n3 is 0 or 1; provided that any of three X d 's contains a fluorine atom.
上記フッ素化アルコキシ基（ｃ）の具体例としては、上記一般式（ａ－１）におけるＲ１として例示したアルキル基の末端に酸素原子が結合したフッ素化アルコキシ基が挙げられる。 Specific examples of the fluorinated alkoxy group (c) include a fluorinated alkoxy group in which an oxygen atom is bonded to the end of the alkyl group exemplified as R 1 in the general formula (a-1).
上記フッ素化飽和環状カーボネートにおけるフッ素化アルキル基（ａ）、エーテル結合を有するフッ素化アルキル基（ｂ）、及び、フッ素化アルコキシ基（ｃ）のフッ素含有率は１０質量％以上が好ましい。フッ素含有率が低過ぎると、低温での粘性低下効果や引火点の上昇効果が充分に得られないおそれがある。この観点から上記フッ素含有率は１２質量％以上がより好ましく、１５質量％以上が更に好ましい。上限は通常７６質量％である。
フッ素化アルキル基（ａ）、エーテル結合を有するフッ素化アルキル基（ｂ）、及び、フッ素化アルコキシ基（ｃ）のフッ素含有率は、各基の構造式に基づいて、｛（フッ素原子の個数×１９）／各基の式量｝×１００（％）により算出した値である。 The fluorine content of the fluorinated alkyl group (a) in the fluorinated saturated cyclic carbonate, the fluorinated alkyl group (b) having an ether bond, and the fluorinated alkoxy group (c) is preferably 10% by mass or more. If the fluorine content is too low, the viscosity lowering effect at low temperatures and the flash point raising effect may not be sufficiently obtained. From this viewpoint, the fluorine content is more preferably 12% by mass or more, and still more preferably 15% by mass or more. The upper limit is usually 76% by mass.
The fluorine content of the fluorinated alkyl group (a), the fluorinated alkyl group (b) having an ether bond, and the fluorinated alkoxy group (c) is {(number of fluorine atoms based on the structural formula of each group It is the value computed by x19) / formula weight of each group} x 100 (%).
また、誘電率、耐酸化性が良好な点からは、上記フッ素化飽和環状カーボネート全体のフッ素含有率は１０質量％以上が好ましく、１５質量％以上がより好ましい。上限は通常７６質量％である。
なお、上記フッ素化飽和環状カーボネートのフッ素含有率は、フッ素化飽和環状カーボネートの構造式に基づいて、｛（フッ素原子の個数×１９）／フッ素化飽和環状カーボネートの分子量｝×１００（％）により算出した値である。 Further, from the viewpoint of good dielectric constant and oxidation resistance, the fluorine content of the entire fluorinated saturated cyclic carbonate is preferably 10% by mass or more, and more preferably 15% by mass or more. The upper limit is usually 76% by mass.
The fluorine content of the fluorinated saturated cyclic carbonate is determined by {(number of fluorine atoms × 19) / molecular weight of fluorinated saturated cyclic carbonate} × 100 (%) based on the structural formula of fluorinated saturated cyclic carbonate It is a calculated value.
上記フッ素化飽和環状カーボネートとしては、具体的には、例えば、以下が挙げられる。 Specific examples of the fluorinated saturated cyclic carbonate include the following.
Ｘ１～Ｘ４の少なくとも１つが－Ｆであるフッ素化飽和環状カーボネートの具体例として、 As specific examples of the fluorinated saturated cyclic carbonate in which at least one of X 1 to X 4 is -F,
Figure JPOXMLDOC01-appb-C000028
 等が挙げられる。これらの化合物は、耐電圧が高く、電解質塩の溶解性も良好である。
Figure JPOXMLDOC01-appb-C000028
 Etc. These compounds have high withstand voltage and good solubility of the electrolyte salt.
他に、 other,
Figure JPOXMLDOC01-appb-C000029
Figure JPOXMLDOC01-appb-C000029
等も使用できる。 Etc. can also be used.
Ｘ１～Ｘ４の少なくとも１つがフッ素化アルキル基（ａ）であり、かつ残りが全て－Ｈであるフッ素化飽和環状カーボネートの具体例としては、 Specific examples of the fluorinated saturated cyclic carbonate in which at least one of X 1 to X 4 is a fluorinated alkyl group (a) and the rest are all —H are as follows:
Figure JPOXMLDOC01-appb-C000030
Figure JPOXMLDOC01-appb-C000030
Figure JPOXMLDOC01-appb-C000031
Figure JPOXMLDOC01-appb-C000031
Figure JPOXMLDOC01-appb-C000032
Figure JPOXMLDOC01-appb-C000032
等が挙げられる。 Etc.
Ｘ１～Ｘ４の少なくとも１つが、エーテル結合を有するフッ素化アルキル基（ｂ）、又は、フッ素化アルコキシ基（ｃ）であり、かつ残りが全て－Ｈであるフッ素化飽和環状カーボネートの具体例としては、 Specific examples of the fluorinated saturated cyclic carbonate in which at least one of X 1 to X 4 is a fluorinated alkyl group (b) having an ether bond or a fluorinated alkoxy group (c) and the rest is all -H. as,
Figure JPOXMLDOC01-appb-C000033
Figure JPOXMLDOC01-appb-C000033
Figure JPOXMLDOC01-appb-C000034
Figure JPOXMLDOC01-appb-C000034
Figure JPOXMLDOC01-appb-C000035
Figure JPOXMLDOC01-appb-C000035
Figure JPOXMLDOC01-appb-C000036
Figure JPOXMLDOC01-appb-C000036
Figure JPOXMLDOC01-appb-C000037
Figure JPOXMLDOC01-appb-C000037
Figure JPOXMLDOC01-appb-C000038
Figure JPOXMLDOC01-appb-C000038
等が挙げられる。 Etc.
なかでも、上記フッ素化飽和環状カーボネートとしては、以下の化合物のいずれかであることが好ましい。 Among them, the fluorinated saturated cyclic carbonate is preferably any of the following compounds.
Figure JPOXMLDOC01-appb-C000039
Figure JPOXMLDOC01-appb-C000039
Figure JPOXMLDOC01-appb-C000040
Figure JPOXMLDOC01-appb-C000040
上記フッ素化飽和環状カーボネートとしては、その他にも、ｔｒａｎｓ－４，５－ジフルオロ－１，３－ジオキソラン－２－オン、５－（１，１－ジフルオロエチル）－４，４－ジフルオロ－１，３－ジオキソラン－２－オン、４－メチレン－１，３－ジオキソラン－２－オン、４－メチル－５－トリフルオロメチル－１，３－ジオキソラン－２－オン、４－エチル－５－フルオロ－１，３－ジオキソラン－２－オン、４－エチル－５，５－ジフルオロ－１，３－ジオキソラン－２－オン、４－エチル－４，５－ジフルオロ－１，３－ジオキソラン－２－オン、４－エチル－４，５，５－トリフルオロ－１，３－ジオキソラン－２－オン、４，４－ジフルオロ－５－メチル－１，３－ジオキソラン－２－オン、４－フルオロ－５－メチル－１，３－ジオキソラン－２－オン、４－フルオロ－５－トリフルオロメチル－１，３－ジオキソラン－２－オン、４，４－ジフルオロ－１，３－ジオキソラン－２－オン等が挙げられる。 In addition to the above-mentioned fluorinated saturated cyclic carbonate, trans-4,5-difluoro-1,3-dioxolan-2-one, 5- (1,1-difluoroethyl) -4,4-difluoro-1, 3-dioxolan-2-one, 4-methylene-1,3-dioxolan-2-one, 4-methyl-5-trifluoromethyl-1,3-dioxolan-2-one, 4-ethyl-5-fluoro- 1,3-dioxolan-2-one, 4-ethyl-5,5-difluoro-1,3-dioxolan-2-one, 4-ethyl-4,5-difluoro-1,3-dioxolan-2-one, 4-ethyl-4,5,5-trifluoro-1,3-dioxolan-2-one, 4,4-difluoro-5-methyl-1,3-dioxolan-2-one, 4-fluoro-5-methyl -1 3-dioxolan-2-one, 4-fluoro-5-trifluoromethyl-1,3-dioxolan-2-one, 4,4-difluoro-1,3-dioxolan-2-one, and the like.
上記フッ素化飽和環状カーボネートとしては、なかでも、フルオロエチレンカーボネート、ジフルオロエチレンカーボネート、トリフルオロメチルエチレンカーボネート（３，３，３－トリフルオロプロピレンカーボネート）、２，２，３，３，３－ペンタフルオロプロピルエチレンカーボネートがより好ましい。 Among the above fluorinated saturated cyclic carbonates, fluoroethylene carbonate, difluoroethylene carbonate, trifluoromethylethylene carbonate (3,3,3-trifluoropropylene carbonate), 2,2,3,3,3-pentafluoro, among others Propyl ethylene carbonate is more preferred.
上記フッ素化不飽和環状カーボネートは、不飽和結合とフッ素原子とを有する環状カーボネートであり、芳香環又は炭素－炭素二重結合を有する置換基で置換されたフッ素化エチレンカーボネート誘導体が好ましい。具体的には、４，４－ジフルオロ－５－フェニルエチレンカーボネート、４，５－ジフルオロ－４－フェニルエチレンカーボネート、４－フルオロ－５－フェニルエチレンカーボネート、４－フルオロ－５－ビニルエチレンカーボネート、４－フルオロ－４－フェニルエチレンカーボネート、４，４－ジフルオロ－４－ビニルエチレンカーボネート、４，４－ジフルオロ－４－アリルエチレンカーボネート、４－フルオロ－４－ビニルエチレンカーボネート、４－フルオロ－４，５－ジアリルエチレンカーボネート、４，５－ジフルオロ－４－ビニルエチレンカーボネート、４，５－ジフルオロ－４，５－ジビニルエチレンカーボネート、４，５－ジフルオロ－４，５－ジアリルエチレンカーボネート等が挙げられる。 The fluorinated unsaturated cyclic carbonate is a cyclic carbonate having an unsaturated bond and a fluorine atom, and is preferably a fluorinated ethylene carbonate derivative substituted with a substituent having an aromatic ring or a carbon-carbon double bond. Specifically, 4,4-difluoro-5-phenylethylene carbonate, 4,5-difluoro-4-phenylethylene carbonate, 4-fluoro-5-phenylethylene carbonate, 4-fluoro-5-vinylethylene carbonate, 4 -Fluoro-4-phenylethylene carbonate, 4,4-difluoro-4-vinylethylene carbonate, 4,4-difluoro-4-allylethylene carbonate, 4-fluoro-4-vinylethylene carbonate, 4-fluoro-4,5 And -diallyl ethylene carbonate, 4,5-difluoro-4-vinyl ethylene carbonate, 4,5-difluoro-4,5-divinyl ethylene carbonate, 4,5-difluoro-4,5-diallyl ethylene carbonate and the like.
上記フッ素化環状カーボネートは、１種を単独で用いてもよく、２種以上を任意の組み合わせ及び比率で併用してもよい。 The fluorinated cyclic carbonates may be used alone or in any combination of two or more in any proportion.
上記フッ素化環状カーボネートが含まれる場合、上記フッ素化環状カーボネートの含有量は、上記溶媒に対して５～９０体積％であることが好ましく、１０～６０体積％であることがより好ましく、１５～４５体積％であることが更に好ましい。 When the fluorinated cyclic carbonate is contained, the content of the fluorinated cyclic carbonate is preferably 5 to 90% by volume, more preferably 10 to 60% by volume, with respect to the solvent, and 15 to 50% by volume. More preferably, it is 45% by volume.
上記鎖状カーボネートは、非フッ素化鎖状カーボネートであってもよいし、フッ素化鎖状カーボネートであってもよい。 The linear carbonate may be a non-fluorinated linear carbonate or a fluorinated linear carbonate.
上記非フッ素化鎖状カーボネートとしては、例えば、ＣＨ３ＯＣＯＯＣＨ３（ジメチルカーボネート：ＤＭＣ）、ＣＨ３ＣＨ２ＯＣＯＯＣＨ２ＣＨ３（ジエチルカーボネート：ＤＥＣ）、ＣＨ３ＣＨ２ＯＣＯＯＣＨ３（エチルメチルカーボネート：ＥＭＣ）、ＣＨ３ＯＣＯＯＣＨ２ＣＨ２ＣＨ３（メチルプロピルカーボネート）、メチルブチルカーボネート、エチルプロピルカーボネート、エチルブチルカーボネート、ジプロピルカーボネート、ジブチルカーボネート、メチルイソプロピルカーボネート、メチル－２－フェニルフェニルカーボネート、フェニル－２－フェニルフェニルカーボネート、トランス－２，３－ペンチレンカーボネート、トランス－２，３－ブチレンカーボネート、エチルフェニルカーボネート等の炭化水素系鎖状カーボネートが挙げられる。なかでも、エチルメチルカーボネート、ジエチルカーボネート及びジメチルカーボネートからなる群より選択される少なくとも１種であることが好ましい。 Examples of the non-fluorinated linear carbonates include CH 3 OCOOCH 3 (dimethyl carbonate: DMC), CH 3 CH 2 OCOOCH 2 CH 3 (diethyl carbonate: DEC), CH 3 CH 2 OCOOCH 3 (ethyl methyl carbonate: EMC) ), CH 3 OCOOCH 2 CH 2 CH 3 (methyl propyl carbonate), methyl butyl carbonate, ethyl propyl carbonate, ethyl butyl carbonate, dipropyl carbonate, dibutyl carbonate, methyl isopropyl carbonate, methyl 2-phenylphenyl carbonate, phenyl-2 -Phenylphenyl carbonate, trans-2,3-pentylene carbonate, trans-2,3-butylene carbonate, ethyl phenyl carbonate It includes hydrocarbon chain carbonate. Among them, at least one selected from the group consisting of ethyl methyl carbonate, diethyl carbonate and dimethyl carbonate is preferable.
上記非フッ素化鎖状カーボネートは、１種を単独で用いてもよく、２種以上を任意の組み合わせ及び比率で併用してもよい。 The above non-fluorinated linear carbonates may be used alone or in any combination of two or more in any proportion.
上記非フッ素化鎖状カーボネートが含まれる場合、上記非フッ素化鎖状カーボネートの含有量は、上記溶媒に対して１０～９０体積％であることが好ましく、４０～８５体積％であることがより好ましく、５０～８０体積％であることが更に好ましい。 When the non-fluorinated linear carbonate is contained, the content of the non-fluorinated linear carbonate is preferably 10 to 90% by volume, more preferably 40 to 85% by volume with respect to the solvent. Preferably, it is 50 to 80% by volume.
上記フッ素化鎖状カーボネートは、フッ素原子を有する鎖状カーボネートである。フッ素化鎖状カーボネートを含む溶媒は、高電圧下でも好適に使用することができる。 The fluorinated linear carbonate is a linear carbonate having a fluorine atom. The solvent containing fluorinated linear carbonate can be suitably used even under high voltage.
上記フッ素化鎖状カーボネートとしては、一般式（Ｂ）：
Ｒｆ２ＯＣＯＯＲ７　　　　　（Ｂ）
（式中、Ｒｆ２は、炭素数１～７のフッ素化アルキル基であり、Ｒ７は、炭素数１～７のフッ素原子を含んでいてもよいアルキル基である。）で示される化合物を挙げることができる。 As said fluorinated linear carbonate, general formula (B):
Rf 2 OCOOR 7 (B)
(Wherein, R f 2 is a fluorinated alkyl group having 1 to 7 carbon atoms, and R 7 is an alkyl group having 1 to 7 carbon atoms which may contain a fluorine atom) It can be mentioned.
Ｒｆ２は、炭素数１～７のフッ素化アルキル基であり、Ｒ７は、炭素数１～７のフッ素原子を含んでいてもよいアルキル基である。
上記フッ素化アルキル基は、アルキル基が有する水素原子の少なくとも１つをフッ素原子で置換したものである。Ｒ７がフッ素原子を含むアルキル基である場合、フッ素化アルキル基となる。
Ｒｆ２及びＲ７は、低粘性である点で、炭素数が１～７であることが好ましく、１～２であることがより好ましい。
炭素数が大きくなりすぎると低温特性が低下したり、電解質塩の溶解性が低下したりするおそれがあり、炭素数が少な過ぎると、電解質塩の溶解性の低下、放電効率の低下、更には粘性の増大等がみられることがある。 Rf 2 is a fluorinated alkyl group having 1 to 7 carbon atoms, and R 7 is an alkyl group which may contain a fluorine atom having 1 to 7 carbon atoms.
The said fluorinated alkyl group substitutes at least one of the hydrogen atoms which an alkyl group has with a fluorine atom. When R 7 is an alkyl group containing a fluorine atom, it is a fluorinated alkyl group.
From the viewpoint of low viscosity, Rf 2 and R 7 preferably have 1 to 7 carbon atoms, and more preferably 1 to 2 carbon atoms.
If the number of carbons is too large, the low temperature characteristics may deteriorate or the solubility of the electrolyte salt may decrease. If the number of carbons is too small, the solubility of the electrolyte salt may decrease, the discharge efficiency may decrease, and further An increase in viscosity etc. may be observed.
炭素数が１のフッ素化アルキル基としては、ＣＦＨ２－、ＣＦ２Ｈ－、ＣＦ３－等が挙げられる。特に、ＣＦＨ２－又はＣＦ３－が高温保存特性上好ましい。 Examples of the fluorinated alkyl group having 1 carbon atom include CFH 2- , CF 2 H-, and CF 3- . In particular, CFH 2 -or CF 3 -is preferable in view of high temperature storage characteristics.
炭素数が２以上のフッ素化アルキル基としては、下記一般式（ｄ－１）：
Ｒ１－Ｒ２－　（ｄ－１）
（式中、Ｒ１はフッ素原子を有していてもよい炭素数１以上のアルキル基；Ｒ２はフッ素原子を有していてもよい炭素数１～３のアルキレン基；ただし、Ｒ１及びＲ２の少なくとも一方はフッ素原子を有している）で示されるフッ素化アルキル基が、電解質塩の溶解性が良好な点から好ましく例示できる。
なお、Ｒ１及びＲ２は、更に、炭素原子、水素原子及びフッ素原子以外の、その他の原子を有していてもよい。 Examples of the fluorinated alkyl group having 2 or more carbon atoms include the following general formula (d-1):
R 1 -R 2- (d-1)
(Wherein, R 1 is an alkyl group having 1 or more carbon atoms which may have a fluorine atom; R 2 is an alkylene group having 1 to 3 carbon atoms which may have a fluorine atom; however, R 1 and The fluorinated alkyl group represented by at least one of R 2 s having a fluorine atom can be preferably exemplified from the viewpoint of good solubility of the electrolyte salt.
R 1 and R 2 may further have other atoms than carbon atoms, hydrogen atoms and fluorine atoms.
Ｒ１は、フッ素原子を有していてもよい炭素数１以上のアルキル基である。Ｒ１としては、炭素数１～６の直鎖状又は分岐鎖状のアルキル基が好ましい。Ｒ１の炭素数としては、１～３がより好ましい。 R 1 is an alkyl group having one or more carbon atoms which may have a fluorine atom. As R 1 , a linear or branched alkyl group having 1 to 6 carbon atoms is preferable. The number of carbon atoms of R 1 is more preferably 1 to 3.
Ｒ１として、具体的には、直鎖状又は分岐鎖状のアルキル基として、ＣＨ３－、ＣＦ３－、ＣＨ３ＣＨ２－、ＣＨ３ＣＨ２ＣＨ２－、ＣＨ３ＣＨ２ＣＨ２ＣＨ２－、 As R 1 , specifically, as a linear or branched alkyl group, CH 3- , CF 3- , CH 3 CH 2- , CH 3 CH 2 CH 2- , CH 3 CH 2 CH 2 CH 2- ,
Figure JPOXMLDOC01-appb-C000041
Figure JPOXMLDOC01-appb-C000041
等が挙げられる。 Etc.
また、Ｒ１がフッ素原子を有する直鎖状のアルキル基である場合、ＣＦ３－、ＣＦ３ＣＨ２－、ＣＦ３ＣＦ２－、ＣＦ３ＣＨ２ＣＨ２－、ＣＦ３ＣＦ２ＣＨ２－、ＣＦ３ＣＦ２ＣＦ２－、ＣＦ３ＣＨ２ＣＦ２－、ＣＦ３ＣＨ２ＣＨ２ＣＨ２－、ＣＦ３ＣＦ２ＣＨ２ＣＨ２－、ＣＦ３ＣＨ２ＣＦ２ＣＨ２－、ＣＦ３ＣＦ２ＣＦ２ＣＨ２－、ＣＦ３ＣＦ２ＣＦ２ＣＦ２－、ＣＦ３ＣＦ２ＣＨ２ＣＦ２－、ＣＦ３ＣＨ２ＣＨ２ＣＨ２ＣＨ２－、ＣＦ３ＣＦ２ＣＨ２ＣＨ２ＣＨ２－、ＣＦ３ＣＨ２ＣＦ２ＣＨ２ＣＨ２－、ＣＦ３ＣＦ２ＣＦ２ＣＨ２ＣＨ２－、ＣＦ３ＣＦ２ＣＦ２ＣＦ２ＣＨ２－、ＣＦ３ＣＦ２ＣＨ２ＣＦ２ＣＨ２－、ＣＦ３ＣＦ２ＣＨ２ＣＨ２ＣＨ２ＣＨ２－、ＣＦ３ＣＦ２ＣＦ２ＣＦ２ＣＨ２ＣＨ２－、ＣＦ３ＣＦ２ＣＨ２ＣＦ２ＣＨ２ＣＨ２－、ＨＣＦ２－、ＨＣＦ２ＣＨ２－、ＨＣＦ２ＣＦ２－、ＨＣＦ２ＣＨ２ＣＨ２－、ＨＣＦ２ＣＦ２ＣＨ２－、ＨＣＦ２ＣＨ２ＣＦ２－、ＨＣＦ２ＣＦ２ＣＨ２ＣＨ２－、ＨＣＦ２ＣＨ２ＣＦ２ＣＨ２－、ＨＣＦ２ＣＦ２ＣＦ２ＣＦ２－、ＨＣＦ２ＣＦ２ＣＨ２ＣＨ２ＣＨ２－、ＨＣＦ２ＣＨ２ＣＦ２ＣＨ２ＣＨ２－、ＨＣＦ２ＣＦ２ＣＦ２ＣＦ２ＣＨ２－、ＨＣＦ２ＣＦ２ＣＦ２ＣＦ２ＣＨ２ＣＨ２－、ＦＣＨ２－、ＦＣＨ２ＣＨ２－、ＦＣＨ２ＣＦ２－、ＦＣＨ２ＣＦ２ＣＨ２－、ＦＣＨ２ＣＦ２ＣＦ２－、ＣＨ３ＣＦ２ＣＨ２－、ＣＨ３ＣＦ２ＣＦ２－、ＣＨ３ＣＦ２ＣＨ２ＣＦ２－、ＣＨ３ＣＦ２ＣＦ２ＣＦ２－、ＣＨ３ＣＨ２ＣＦ２ＣＦ２－、ＣＨ３ＣＦ２ＣＨ２ＣＦ２ＣＨ２－、ＣＨ３ＣＦ２ＣＦ２ＣＦ２ＣＨ２－、ＣＨ３ＣＦ２ＣＦ２ＣＨ２ＣＨ２－、ＣＨ３ＣＨ２ＣＦ２ＣＦ２ＣＨ２－、ＣＨ３ＣＦ２ＣＨ２ＣＦ２ＣＨ２ＣＨ２－、ＣＨ３ＣＦ２ＣＨ２ＣＦ２ＣＨ２ＣＨ２－、ＨＣＦＣｌＣＦ２ＣＨ２－、ＨＣＦ２ＣＦＣｌＣＨ２－、ＨＣＦ２ＣＦＣｌＣＦ２ＣＦＣｌＣＨ２－、ＨＣＦＣｌＣＦ２ＣＦＣｌＣＦ２ＣＨ２－等が挙げられる。 Moreover, when R 1 is a linear alkyl group having a fluorine atom, CF 3- , CF 3 CH 2- , CF 3 CF 2- , CF 3 CH 2 CH 2- , CF 3 CF 2 CH 2- , CF 3 CF 2 CF 2 - , CF 3 CH 2 CF 2 -, CF 3 CH 2 CH 2 CH 2 -, CF 3 CF 2 CH 2 CH 2 -, CF 3 CH 2 CF 2 CH 2 -, CF 3 CF 2 CF 2 CH 2- , CF 3 CF 2 CF 2 CF 2- , CF 3 CF 2 CH 2 CF 2- , CF 3 CH 2 CH 2 CH 2 CH 2- , CF 3 CF 2 CH 2 CH 2 CH 2- , CF 3 CH 2 CF 2 CH 2 CH 2 -, CF 3 CF 2 CF 2 CH 2 CH 2 -, CF 3 CF 2 CF 2 CF 2 CH 2 -, CF 3 CF 2 CH 2 CF 2 CH 2 -, CF 3 C F 2 CH 2 CH 2 CH 2 CH 2 -, CF 3 CF 2 CF 2 CF 2 CH 2 CH 2 -, CF 3 CF 2 CH 2 CF 2 CH 2 CH 2 -, HCF 2 -, HCF 2 CH 2 -, HCF 2 CF 2 -, HCF 2 CH 2 CH 2 -, HCF 2 CF 2 CH 2 -, HCF 2 CH 2 CF 2 -, HCF 2 CF 2 CH 2 CH 2 -, HCF 2 CH 2 CF 2 CH 2 -, HCF 2 CF 2 CF 2 CF 2- , HCF 2 CF 2 CH 2 CH 2 CH 2- , HCF 2 CH 2 CF 2 CH 2 CH 2- , HCF 2 CF 2 CF 2 CF 2 CF 2 CH 2- , HCF 2 CF 2 CF 2 CF 2 CH 2 CH 2 -, FCH 2 -, FCH 2 CH 2 -, FCH 2 CF 2 -, FCH 2 CF 2 CH 2 -, FCH 2 CF 2 CF 2 - CH 3 CF 2 CH 2 -, CH 3 CF 2 CF 2 -, CH 3 CF 2 CH 2 CF 2 -, CH 3 CF 2 CF 2 CF 2 -, CH 3 CH 2 CF 2 CF 2 -, CH 3 CF 2 CH 2 CF 2 CH 2 -, CH 3 CF 2 CF 2 CF 2 CH 2 -, CH 3 CF 2 CF 2 CH 2 CH 2 -, CH 3 CH 2 CF 2 CF 2 CH 2 -, CH 3 CF 2 CH 2 CF 2 CH 2 CH 2 -, CH 3 CF 2 CH 2 CF 2 CH 2 CH 2 -, HCFClCF 2 CH 2 -, HCF 2 CFClCH 2 -, HCF 2 CFClCF 2 CFClCH 2 -, HCFClCF 2 CFClCF 2 CH 2 - , etc. Can be mentioned.
また、Ｒ１がフッ素原子を有する分岐鎖状のアルキル基である場合、 Moreover, when R 1 is a branched alkyl group having a fluorine atom,
Figure JPOXMLDOC01-appb-C000042
Figure JPOXMLDOC01-appb-C000042
Figure JPOXMLDOC01-appb-C000043
Figure JPOXMLDOC01-appb-C000043
等が好ましく挙げられる。ただし、ＣＨ３－やＣＦ３－という分岐を有していると粘性が高くなりやすいため、その数は少ない（１個）かゼロであることがより好ましい。 Etc. are preferably mentioned. However, since the viscosity is likely to be high when having a branch such as CH 3 -or CF 3- , it is more preferable that the number thereof is small (one) or zero.
Ｒ２はフッ素原子を有していてもよい炭素数１～３のアルキレン基である。Ｒ２は、直鎖状であってもよく、分岐鎖状であってもよい。このような直鎖状又は分岐鎖状のアルキレン基を構成する最小構造単位の一例を下記に示す。Ｒ２はこれらの単独又は組合せで構成される。 R 2 is an alkylene group having 1 to 3 carbon atoms which may have a fluorine atom. R 2 may be linear or branched. An example of the minimum structural unit which comprises such a linear or branched alkylene group is shown below. R 2 is composed of these alone or in combination.
（ｉ）直鎖状の最小構造単位：
－ＣＨ２－、－ＣＨＦ－、－ＣＦ２－、－ＣＨＣｌ－、－ＣＦＣｌ－、－ＣＣｌ２－ (I) Linear minimum structural unit:
-CH 2 -, - CHF -, - CF 2 -, - CHCl -, - CFCl -, - CCl 2 -
（ｉｉ）分岐鎖状の最小構造単位： (Ii) Branched minimum structural unit:
Figure JPOXMLDOC01-appb-C000044
Figure JPOXMLDOC01-appb-C000044
なお、以上の例示のなかでも、塩基による脱ＨＣｌ反応が起こらず、より安定なことから、Ｃｌを含有しない構成単位から構成されることが好ましい。 In addition, among the above exemplifications, it is preferable to be composed of a structural unit not containing Cl, because deHCl reaction with a base does not occur and it is more stable.
Ｒ２は、直鎖状である場合には、上述した直鎖状の最小構造単位のみからなるものであり、なかでも－ＣＨ２－、－ＣＨ２ＣＨ２－又は－ＣＦ２－が好ましい。電解質塩の溶解性をより一層向上させることができる点から、－ＣＨ２－又は－ＣＨ２ＣＨ２－がより好ましい。 When R 2 is linear, it consists only of the above-mentioned linear minimum structural unit, and in particular, —CH 2 —, —CH 2 CH 2 — or —CF 2 — is preferable. -CH 2 -or -CH 2 CH 2 -is more preferable because the solubility of the electrolyte salt can be further improved.
Ｒ２は、分岐鎖状である場合には、上述した分岐鎖状の最小構造単位を少なくとも１つ含んでなるものであり、一般式－（ＣＸａＸｂ）－（ＸａはＨ、Ｆ、ＣＨ３又はＣＦ３；ＸｂはＣＨ３又はＣＦ３。ただし、ＸｂがＣＦ３の場合、ＸａはＨ又はＣＨ３である）で表されるものが好ましく例示できる。これらは特に電解質塩の溶解性をより一層向上させることができる。 When R 2 is branched, it contains at least one of the branched minimum structural units described above, and has a general formula of-(CX a X b )-(X a is H, F , CH 3 or CF 3;. X b is CH 3 or CF 3 provided that when X b is CF 3, X a is one represented by H or CH 3) it can be preferably exemplified. In particular, these can further improve the solubility of the electrolyte salt.
好ましいフッ素化アルキル基としては、具体的には、例えば、ＣＦ３ＣＦ２－、ＨＣＦ２ＣＦ２－、Ｈ２ＣＦＣＦ２－、ＣＨ３ＣＦ２－、ＣＦ３ＣＨ２－、ＣＦ３ＣＦ２ＣＦ２－、ＨＣＦ２ＣＦ２ＣＦ２－、Ｈ２ＣＦＣＦ２ＣＦ２－、ＣＨ３ＣＦ２ＣＦ２－、 Specific preferred fluorinated alkyl groups are, for example, CF 3 CF 2- , HCF 2 CF 2- , H 2 CFCF 2- , CH 3 CF 2- , CF 3 CH 2- , CF 3 CF 2 CF 2- , HCF 2 CF 2 CF 2- , H 2 CFCF 2 CF 2- , CH 3 CF 2 CF 2- ,
Figure JPOXMLDOC01-appb-C000045
Figure JPOXMLDOC01-appb-C000045
Figure JPOXMLDOC01-appb-C000046
Figure JPOXMLDOC01-appb-C000046
等が挙げられる。 Etc.
なかでも、Ｒｆ２とＲ７のフッ素化アルキル基としては、ＣＦ３－、ＣＦ３ＣＦ２－、（ＣＦ３）２ＣＨ－、ＣＦ３ＣＨ２－、Ｃ２Ｆ５ＣＨ２－、ＣＦ３ＣＦ２ＣＨ２－、ＨＣＦ２ＣＦ２ＣＨ２－、ＣＦ３ＣＦＨＣＦ２ＣＨ２－、ＣＦＨ２－、ＣＦ２Ｈ－が好ましく、難燃性が高く、レート特性や耐酸化性が良好な点から、ＣＦ３ＣＨ２－、ＣＦ３ＣＦ２ＣＨ２－、ＨＣＦ２ＣＦ２ＣＨ２－、ＣＦＨ２－、ＣＦ２Ｈ－がより好ましい。 Among them, as fluorinated alkyl groups of Rf 2 and R 7 , CF 3- , CF 3 CF 2- , (CF 3 ) 2 CH-, CF 3 CH 2- , C 2 F 5 CH 2- , CF 3 Preferred are CF 2 CH 2- , HCF 2 CF 2 CH 2- , CF 3 CFHCF 2 CH 2- , CFH 2- , and CF 2 H-, which have high flame retardancy and good rate characteristics and oxidation resistance. , CF 3 CH 2- , CF 3 CF 2 CH 2- , HCF 2 CF 2 CH 2- , CFH 2- , and CF 2 H- are more preferable.
Ｒ７がフッ素原子を含まないアルキル基の場合は炭素数１～７のアルキル基である。Ｒ７は、低粘性である点で、炭素数が１～４であることが好ましく、１～３であることがより好ましい。 When R 7 is an alkyl group not containing a fluorine atom, it is an alkyl group having 1 to 7 carbon atoms. From the viewpoint of low viscosity, R 7 preferably has 1 to 4 carbon atoms, and more preferably 1 to 3 carbon atoms.
上記フッ素原子を含まないアルキル基としては、例えば、ＣＨ３－、ＣＨ３ＣＨ２－、（ＣＨ３）２ＣＨ－、Ｃ３Ｈ７－等が挙げられる。なかでも、粘度が低く、レート特性が良好な点から、ＣＨ３－、ＣＨ３ＣＨ２－が好ましい。 Examples of the above-mentioned alkyl group not containing a fluorine atom include CH 3- , CH 3 CH 2- , (CH 3 ) 2 CH-, C 3 H 7- and the like. Among them, CH 3 -and CH 3 CH 2 -are preferable in terms of low viscosity and good rate characteristics.
上記フッ素化鎖状カーボネートは、フッ素含有率が１５～７０質量％であることが好ましい。フッ素含有率が上述の範囲であると、溶剤との相溶性、塩の溶解性を維持することができる。上記フッ素含有率は、２０質量％以上がより好ましく、３０質量％以上が更に好ましく、３５質量％以上が特に好ましく、６０質量％以下がより好ましく、５０質量％以下が更に好ましい。
なお、本発明においてフッ素含有率は、上記フッ素化鎖状カーボネートの構造式に基づいて、
｛（フッ素原子の個数×１９）／フッ素化鎖状カーボネートの分子量｝×１００（％）
により算出した値である。 The fluorinated linear carbonate preferably has a fluorine content of 15 to 70% by mass. When the fluorine content is in the above-mentioned range, the compatibility with the solvent and the solubility of the salt can be maintained. 20 mass% or more is more preferable, 30 mass% or more is further more preferable, 35 mass% or more is especially preferable, 60 mass% or less is more preferable, and 50 mass% or less is still more preferable.
In the present invention, the fluorine content is based on the structural formula of the above-mentioned fluorinated linear carbonate,
{(Number of fluorine atoms × 19) / molecular weight of fluorinated linear carbonate} × 100 (%)
Is a value calculated by
上記フッ素化鎖状カーボネートとしては、低粘性である点で、以下の化合物のいずれかであることが好ましい。 The fluorinated linear carbonate is preferably any of the following compounds in view of low viscosity.
Figure JPOXMLDOC01-appb-C000047
Figure JPOXMLDOC01-appb-C000047
上記フッ素化鎖状カーボネートとしては、メチル２，２，２－トリフルオロエチルカーボネートが特に好ましい。 As the above-mentioned fluorinated linear carbonate, methyl 2,2,2-trifluoroethyl carbonate is particularly preferable.
上記フッ素化鎖状カーボネートは、１種を単独で用いてもよく、２種以上を任意の組み合わせ及び比率で併用してもよい。 The said fluorinated linear carbonate may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.
上記フッ素化鎖状カーボネートが含まれる場合、上記フッ素化鎖状カーボネートの含有量は、上記溶媒に対して１０～９０体積％であることが好ましく、４０～８５体積％であることがより好ましく、５０～８０体積％であることが更に好ましい。 When the fluorinated linear carbonate is contained, the content of the fluorinated linear carbonate is preferably 10 to 90% by volume, more preferably 40 to 85% by volume, with respect to the solvent. More preferably, it is 50 to 80% by volume.
上記カルボン酸エステルは、環状カルボン酸エステルであってもよいし、鎖状カルボン酸エステルであってもよい。 The carboxylic acid ester may be a cyclic carboxylic acid ester or a linear carboxylic acid ester.
上記環状カルボン酸エステルは、非フッ素化環状カルボン酸エステルであってもよいし、フッ素化環状カルボン酸エステルであってもよい。 The cyclic carboxylic acid ester may be a non-fluorinated cyclic carboxylic acid ester or a fluorinated cyclic carboxylic acid ester.
上記非フッ素化環状カルボン酸エステルとしては、非フッ素化飽和環状カルボン酸エステルが挙げられ、炭素数２～４のアルキレン基を有する非フッ素化飽和環状カルボン酸エステルが好ましい。 Examples of the non-fluorinated cyclic carboxylic acid esters include non-fluorinated saturated cyclic carboxylic acid esters, and preferred are non-fluorinated saturated cyclic carboxylic acid esters having an alkylene group of 2 to 4 carbon atoms.
炭素数２～４のアルキレン基を有する非フッ素化飽和環状カルボン酸エステルの具体的な例としては、β－プロピオラクトン、γ－ブチロラクトン、ε－カプロラクトン、δ－バレロラクトン、αメチル－γ－ブチロラクトンが挙げられる。なかでも、γ－ブチロラクトン、δ－バレロラクトンがリチウムイオン解離度の向上及び負荷特性向上の点から特に好ましい。 Specific examples of the non-fluorinated saturated cyclic carboxylic acid ester having an alkylene group having 2 to 4 carbon atoms include β-propiolactone, γ-butyrolactone, ε-caprolactone, δ-valerolactone, α-methyl-γ- Butyrolactone is mentioned. Among them, γ-butyrolactone and δ-valerolactone are particularly preferable in view of the improvement of the lithium ion dissociation degree and the improvement of the load characteristics.
上記非フッ素化飽和環状カルボン酸エステルは、１種を単独で用いてもよく、２種以上を任意の組み合わせ及び比率で併用してもよい。 The said non-fluorinated saturated cyclic carboxylic acid ester may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.
上記非フッ素化飽和環状カルボン酸エステルが含まれる場合、上記非フッ素化飽和環状カルボン酸エステルの含有量は、上記溶媒に対して０～９０体積％であることが好ましく、０．００１～９０体積％であることがより好ましく、１～６０体積％であることが更に好ましく、５～４０体積％であることが特に好ましい。 When the non-fluorinated saturated cyclic carboxylic acid ester is contained, the content of the non-fluorinated saturated cyclic carboxylic acid ester is preferably 0 to 90% by volume with respect to the solvent, and 0.001 to 90 volumes. % Is more preferable, 1 to 60% by volume is further preferable, and 5 to 40% by volume is particularly preferable.
上記鎖状カルボン酸エステルは、非フッ素化鎖状カルボン酸エステルであってもよいし、フッ素化鎖状カルボン酸エステルであってもよい。 The chain carboxylic acid ester may be a non-fluorinated chain carboxylic acid ester or a fluorinated chain carboxylic acid ester.
上記非フッ素化鎖状カルボン酸エステルとしては、例えば、酢酸メチル、酢酸エチル、酢酸プロピル、酢酸ブチル、プロピオン酸メチル、プロピオン酸エチル、プロピオン酸プロピル、プロピオン酸ブチル、ｔｅｒｔ－ブチルプロピオネート、ｔｅｒｔ－ブチルブチレート、ｓｅｃ－ブチルプロピオネート、ｓｅｃ－ブチルブチレート、ｎ－ブチルブチレート、ピロリン酸メチル、ピロリン酸エチル、ｔｅｒｔ－ブチルホルメート、ｔｅｒｔ－ブチルアセテート、ｓｅｃ－ブチルホルメート、ｓｅｃ－ブチルアセテート、ｎ－ヘキシルピバレート、ｎ－プロピルホルメート、ｎ－プロピルアセテート、ｎ－ブチルホルメート、ｎ－ブチルピバレート、ｎ－オクチルピバレート、エチル　２－（ジメトキシホスホリル）アセテート、エチル　２－（ジメチルホスホリル）アセテート、エチル　２－（ジエトキシホスホリル）アセテート、エチル　２－（ジエチルホスホリル）アセテート、イソプロピルプロピオネート、イソプロピルアセテート、エチルホルメート、エチル　２－プロピニルオギザレート、イソプロピルホルメート、イソプロピルブチレート、イソブチルホルメート、イソブチルプロピオネート、イソブチルブチレート、イソブチルアセテート等が挙げられる。 Examples of the non-fluorinated linear carboxylic acid ester include methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl propionate, ethyl propionate, propyl propionate, butyl propionate, tert-butyl propionate, tert. -Butyl butyrate, sec-butyl propionate, sec-butyl butyrate, n-butyl butyrate, methyl pyrophosphate, ethyl pyrophosphate, tert-butyl formate, tert-butyl acetate, sec-butyl formate, sec -Butyl acetate, n-hexyl pivalate, n-propyl formate, n-propyl acetate, n-butyl formate, n-butyl pivalate, n-octyl pivalate, ethyl 2- (dimethoxyphosphoryl) acetate, ethyl 2 (Dimethylphosphoryl) acetate, ethyl 2- (diethoxyphosphoryl) acetate, ethyl 2- (diethylphosphoryl) acetate, isopropyl propionate, isopropyl acetate, ethyl formate, ethyl 2-propynyl oxime, isopropyl formate, isopropyl Examples include butyrate, isobutyl formate, isobutyl propionate, isobutyl butyrate, isobutyl acetate and the like.
なかでも、酢酸ブチル、プロピオン酸メチル、プロピオン酸エチル、プロピオン酸プロピル、プロピオン酸ブチルが好ましく、特に好ましくはプロピオン酸エチル、プロピオン酸プロピルである。 Among them, butyl acetate, methyl propionate, ethyl propionate, propyl propionate and butyl propionate are preferable, and ethyl propionate and propyl propionate are particularly preferable.
上記非フッ素化鎖状カルボン酸エステルは、１種を単独で用いてもよく、２種以上を任意の組み合わせ及び比率で併用してもよい。 The non-fluorinated linear carboxylic acid esters may be used alone or in any combination and ratio of two or more.
上記非フッ素化鎖状カルボン酸エステルが含まれる場合、上記非フッ素化鎖状カルボン酸エステルの含有量は、上記溶媒に対して０～９０体積％であることが好ましく、０．００１～９０体積％であることがより好ましく、１～６０体積％であることが更に好ましく、５～４０体積％であることが特に好ましい。 When the non-fluorinated linear carboxylic acid ester is contained, the content of the non-fluorinated linear carboxylic acid ester is preferably 0 to 90% by volume with respect to the solvent, and 0.001 to 90 volumes. % Is more preferable, 1 to 60% by volume is further preferable, and 5 to 40% by volume is particularly preferable.
上記フッ素化鎖状カルボン酸エステルは、フッ素原子を有する鎖状カルボン酸エステルである。フッ素化鎖状カルボン酸エステルを含む溶媒は、高電圧下でも好適に使用することができる。 The fluorinated linear carboxylic acid ester is a linear carboxylic acid ester having a fluorine atom. The solvent containing the fluorinated linear carboxylic acid ester can be suitably used even under high voltage.
上記フッ素化鎖状カルボン酸エステルとしては、下記一般式：
Ｒｆ３１ＣＯＯＲｆ３２
（式中、Ｒｆ３１は炭素数１～４のフッ素化アルキル基、Ｒｆ３２は炭素数１～４のフッ素原子を含んでいてもよいアルキル基）で示されるフッ素化鎖状カルボン酸エステルが、他溶媒との相溶性や耐酸化性が良好な点から好ましい。 As said fluorinated linear carboxylic acid ester, the following general formula:
Rf 31 COORf 32
(Wherein, R f 31 is a fluorinated alkyl group having 1 to 4 carbon atoms, R f 32 is an alkyl group optionally containing a fluorine atom having 1 to 4 carbon atoms), and a fluorinated linear carboxylic acid ester is It is preferable from the viewpoint of good compatibility with other solvents and oxidation resistance.
Ｒｆ３１としては、例えばＨＣＦ２－、ＣＦ３－、ＣＦ３ＣＦ２－、ＨＣＦ２ＣＦ２－、ＣＨ３ＣＦ２－、ＣＦ３ＣＨ２－等が例示でき、なかでもＨＣＦ２－、ＣＦ３－、ＣＦ３ＣＦ２－、ＣＦ３ＣＨ２－が粘度、耐酸化性が良好な点から特に好ましい。 Examples of Rf 31 include HCF 2- , CF 3- , CF 3 CF 2- , HCF 2 CF 2- , CH 3 CF 2- , CF 3 CH 2- and the like, and among them, HCF 2- , CF 3- -, CF 3 CF 2 -and CF 3 CH 2 -are particularly preferable from the viewpoint of good viscosity and oxidation resistance.
Ｒｆ３２としては、例えば、ＣＨ３－、Ｃ２Ｈ５－、ＣＦ３－、ＣＦ３ＣＦ２－、（ＣＦ３）２ＣＨ－、ＣＦ３ＣＨ２－、ＣＦ３ＣＨ２ＣＨ２－、ＣＦ３ＣＦＨＣＦ２ＣＨ２－、Ｃ２Ｆ５ＣＨ２－、ＣＦ２ＨＣＦ２ＣＨ２－、Ｃ２Ｆ５ＣＨ２ＣＨ２－、ＣＦ３ＣＦ２ＣＨ２－、ＣＦ３ＣＦ２ＣＦ２ＣＨ２－等が例示でき、なかでもＣＨ３－、Ｃ２Ｈ５－、ＣＦ３ＣＨ２－、ＣＦ３ＣＨ２ＣＨ２－が、他溶媒との相溶性が良好な点から特に好ましい。 As Rf 32 , for example, CH 3- , C 2 H 5- , CF 3- , CF 3 CF 2- , (CF 3 ) 2 CH-, CF 3 CH 2- , CF 3 CH 2 CH 2- , CF 3 3 CFHCF 2 CH 2 -, C 2 F 5 CH 2 -, CF 2 HCF 2 CH 2 -, C 2 F 5 CH 2 CH 2 -, CF 3 CF 2 CH 2 -, CF 3 CF 2 CF 2 CH 2 - Among them, CH 3- , C 2 H 5- , CF 3 CH 2- , and CF 3 CH 2 CH 2 -are particularly preferable because of their good compatibility with other solvents.
上記フッ素化鎖状カルボン酸エステルの具体例としては、例えばＣＦ３ＣＨ２Ｃ（＝Ｏ）ＯＣＨ３（３，３，３－トリフルオロプロピオン酸メチル）、ＨＣＦ２Ｃ（＝Ｏ）ＯＣＨ３（ジフルオロ酢酸メチル）、ＨＣＦ２Ｃ（＝Ｏ）ＯＣ２Ｈ５（ジフルオロ酢酸エチル）、ＣＦ３Ｃ（＝Ｏ）ＯＣＨ２ＣＨ２ＣＦ３、ＣＦ３Ｃ（＝Ｏ）ＯＣＨ２Ｃ２Ｆ５、ＣＦ３Ｃ（＝Ｏ）ＯＣＨ２ＣＦ２ＣＦ２Ｈ（トリフルオロ酢酸２，２，３，３－テトラフルオロプロピル）、ＣＦ３Ｃ（＝Ｏ）ＯＣＨ２ＣＦ３、ＣＦ３Ｃ（＝Ｏ）ＯＣＨ（ＣＦ３）２、ペンタフルオロ酪酸エチル、ペンタフルオロプロピオン酸メチル、ペンタフルオロプロピオン酸エチル、ペンタフルオロイソ酪酸メチル、トリフルオロ酪酸イソプロピル、トリフルオロ酢酸エチル、トリフルオロ酢酸ｔｅｒｔ－ブチル、トリフルオロ酢酸ｎ－ブチル、テトラフルオロ－２－（メトキシ）プロピオン酸メチル、酢酸２，２－ジフルオロエチル、酢酸２，２，３，３－テトラフルオロプロピル、酢酸２，２，２－トリフルオロエチル、酢酸１Ｈ，１Ｈ－ヘプタフルオロブチル、４，４，４－トリフルオロ酪酸メチル、４，４，４－トリフルオロ酪酸エチル、３，３，３－トリフルオロプロピオン酸エチル、３，３，３－トリフルオロプロピオン酸３，３，３トリフルオロプロピル、３－（トリフルオロメチル）酪酸エチル、２，３，３，３－テトラフルオロプロピオン酸メチル、２，２－ジフルオロ酢酸ブチル、２，２，３，３－テトラフルオロプロピオン酸メチル、２－（トリフルオロメチル）－３，３，３－トリフルオロプロピオン酸メチル、ヘプタフルオロ酪酸メチル等の１種又は２種以上が例示できる。
なかでもＣＦ３ＣＨ２Ｃ（＝Ｏ）ＯＣＨ３、ＨＣＦ２Ｃ（＝Ｏ）ＯＣＨ３、ＨＣＦ２Ｃ（＝Ｏ）ＯＣ２Ｈ５、ＣＦ３Ｃ（＝Ｏ）ＯＣＨ２Ｃ２Ｆ５、ＣＦ３Ｃ（＝Ｏ）ＯＣＨ２ＣＦ２ＣＦ２Ｈ、ＣＦ３Ｃ（＝Ｏ）ＯＣＨ２ＣＦ３、ＣＦ３Ｃ（＝Ｏ）ＯＣＨ（ＣＦ３）２、ペンタフルオロ酪酸エチル、ペンタフルオロプロピオン酸メチル、ペンタフルオロプロピオン酸エチル、ペンタフルオロイソ酪酸メチル、トリフルオロ酪酸イソプロピル、トリフルオロ酢酸エチル、トリフルオロ酢酸ｔｅｒｔ－ブチル、トリフルオロ酢酸ｎ－ブチル、テトラフルオロ－２－（メトキシ）プロピオン酸メチル、酢酸２，２－ジフルオロエチル、酢酸２，２，３，３－テトラフルオロプロピル、酢酸２，２，２－トリフルオロエチル、酢酸１Ｈ，１Ｈ－ヘプタフルオロブチル、４，４，４－トリフルオロ酪酸メチル、４，４，４－トリフルオロ酪酸エチル、３，３，３－トリフルオロプロピオン酸エチル、３，３，３－トリフルオロプロピオン酸３，３，３－トリフルオロプロピル、３－（トリフルオロメチル）酪酸エチル、２，３，３，３－テトラフルオロプロピオン酸メチル、２，２－ジフルオロ酢酸ブチル、２，２，３，３－テトラフルオロプロピオン酸メチル、２－（トリフルオロメチル）－３，３，３－トリフルオロプロピオン酸メチル、ヘプタフルオロ酪酸メチルが、他溶媒との相溶性及びレート特性が良好な点から好ましく、ＣＦ３ＣＨ２Ｃ（＝Ｏ）ＯＣＨ３、ＨＣＦ２Ｃ（＝Ｏ）ＯＣＨ３、ＨＣＦ２Ｃ（＝Ｏ）ＯＣ２Ｈ５がより好ましく、ＨＣＦ２Ｃ（＝Ｏ）ＯＣＨ３、ＨＣＦ２Ｃ（＝Ｏ）ＯＣ２Ｈ５が特に好ましい。 Specific examples of the fluorinated linear carboxylic acid ester include CF 3 CH 2 C (= O) OCH 3 (methyl 3,3,3-trifluoropropionate), HCF 2 C (= O) OCH 3 ( Methyl difluoroacetate), HCF 2 C (= O) OC 2 H 5 (ethyl difluoroacetate), CF 3 C (= O) OCH 2 CH 2 CF 3 , CF 3 C (= O) OCH 2 C 2 F 5 , CF 3 C (= O) OCH 2 CF 2 CF 2 H (trifluoroacetic acid 2,2,3,3-tetrafluoropropyl), CF 3 C (= O) OCH 2 CF 3 , CF 3 C (= O) OCH (CF 3 ) 2 , ethyl pentafluorobutyrate, methyl pentafluoropropionate, ethyl pentafluoropropionate, methyl pentafluoroisobutyrate, isopropyl trifluorobutyrate , Trifluoroacetate ethyl, tert-butyl trifluoroacetate, n-butyl trifluoroacetate, methyl tetrafluoro-2- (methoxy) propionate, 2,2-difluoroethyl acetate, 2,2,3,3-tetraacetate Fluoropropyl, 2,2,2-trifluoroethyl acetate, 1H, 1H-heptafluorobutyl acetate, methyl 4,4,4-trifluorobutyrate, ethyl 4,4,4-trifluorobutyrate, 3,3,3,3 Ethyl trifluoropropionate, 3,3,3 trifluoropropyl acid 3,3,3 trifluoropropyl acid, ethyl 3- (trifluoromethyl) butyrate, methyl 2,3,3,3-tetrafluoropropionate, 2,2-Difluorobutyl acetate, methyl 2,2,3,3-tetrafluoropropionate, 2- (trifluoromethyl) 3,3,3 methyl, one methyl heptafluoro butyrate or two or more can be exemplified.
Among them, CF 3 CH 2 C (= O) OCH 3 , HCF 2 C (= O) OCH 3 , HCF 2 C (= O) OC 2 H 5 , CF 3 C (= O) OCH 2 C 2 F 5 , CF 3 C (= O) OCH 2 CF 2 CF 2 H, CF 3 C (= O) OCH 2 CF 3, CF 3 C (= O) OCH (CF 3) 2, ethyl pentafluorophenyl butyrate, pentafluorophenyl acid Methyl, ethyl pentafluoropropionate, methyl pentafluoroisobutyrate, isopropyl trifluorobutyrate, ethyl trifluoroacetate, tert-butyl trifluoroacetate, n-butyl trifluoroacetate, methyl tetrafluoro-2- (methoxy) propionate, 2,2-Difluoroethyl acetate, 2,2,3,3-tetrafluoropropyl acetate, 2,2,2-trifluoroacetate 1H, 1H-heptafluorobutyl acetate, methyl 4,4,4-trifluorobutyrate, ethyl 4,4,4-trifluorobutyrate, ethyl 3,3,3-trifluoropropionate, 3,3,3 -Trifluoropropionic acid 3,3,3-trifluoropropyl, ethyl 3- (trifluoromethyl) butyrate, methyl 2,3,3,3-tetrafluoropropionate, butyl 2,2-difluoroacetate, 2,2 Methyl 3,3,3-tetrafluoropropionate, methyl 2- (trifluoromethyl) -3,3,3-trifluoropropionate, methyl heptafluorobutyrate have good compatibility with other solvents and rate characteristics Among them, CF 3 CH 2 C (= O) OCH 3 , HCF 2 C (= O) OCH 3 , and HCF 2 C (= O) OC 2 H 5 are more preferable, and H is preferable. CF 2 C (= O) OCH 3 and HCF 2 C (= O) OC 2 H 5 are particularly preferred.
上記フッ素化鎖状カルボン酸エステルは、１種を単独で用いてもよく、２種以上を任意の組み合わせ及び比率で併用してもよい。 The said fluorinated linear carboxylic acid ester may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.
上記フッ素化鎖状カルボン酸エステルが含まれる場合、上記フッ素化鎖状カルボン酸エステルの含有量は、上記溶媒に対して１０～９０体積％であることが好ましく、４０～８５体積％であることがより好ましく、５０～８０体積％であることが更に好ましい。 When the fluorinated linear carboxylic acid ester is contained, the content of the fluorinated linear carboxylic acid ester is preferably 10 to 90% by volume, preferably 40 to 85% by volume, with respect to the solvent. Is more preferable, and 50 to 80% by volume is even more preferable.
上記溶媒は、上記環状カーボネート、上記鎖状カーボネート及び上記鎖状カルボン酸エステルからなる群より選択される少なくとも１種を含むことが好ましく、上記環状カーボネートと、上記鎖状カーボネート及び上記鎖状カルボン酸エステルからなる群より選択される少なくとも１種とを含むことがより好ましい。上記環状カーボネートは、飽和環状カーボネートであることが好ましい。
上記の組成の溶媒を含有する電解液は、電気化学デバイスの高温保存特性やサイクル特性を一層向上させることができる。 The solvent preferably contains at least one selected from the group consisting of the cyclic carbonate, the linear carbonate, and the linear carboxylic acid ester, and the cyclic carbonate, the linear carbonate, and the linear carboxylic acid. It is more preferable to include at least one selected from the group consisting of esters. The cyclic carbonate is preferably a saturated cyclic carbonate.
The electrolyte containing the solvent of the above composition can further improve the high temperature storage characteristics and the cycle characteristics of the electrochemical device.
上記溶媒が上記環状カーボネートと、上記鎖状カーボネート及び上記鎖状カルボン酸エステルからなる群より選択される少なくとも１種とを含む場合、上記環状カーボネートと、上記鎖状カーボネート及び上記鎖状カルボン酸エステルからなる群より選択される少なくとも１種とを合計で、１０～１００体積％含むことが好ましく、３０～１００体積％含むことがより好ましく、５０～１００体積％含むことが更に好ましい。 When the solvent contains the cyclic carbonate, and at least one selected from the group consisting of the linear carbonate and the linear carboxylic acid ester, the cyclic carbonate, the linear carbonate, and the linear carboxylic acid ester The total content of at least one selected from the group consisting of 10 to 100% by volume is preferable, 30 to 100% by volume is more preferable, and 50 to 100% by volume is more preferable.
上記溶媒が上記環状カーボネートと、上記鎖状カーボネート及び上記鎖状カルボン酸エステルからなる群より選択される少なくとも１種とを含む場合、上記環状カーボネートと、上記鎖状カーボネート及び上記鎖状カルボン酸エステルからなる群より選択される少なくとも１種との体積比としては、５／９５～９５／５が好ましく、１０／９０以上がより好ましく、１５／８５以上が更に好ましく、２０／８０以上が特に好ましく、９０／１０以下がより好ましく、６０／４０以下が更に好ましく、５０／５０以下が特に好ましい。 When the solvent contains the cyclic carbonate, and at least one selected from the group consisting of the linear carbonate and the linear carboxylic acid ester, the cyclic carbonate, the linear carbonate, and the linear carboxylic acid ester The volume ratio to at least one selected from the group consisting of is preferably 5/95 to 95/5, more preferably 10/90 or more, still more preferably 15/85 or more, and particularly preferably 20/80 or more. 90/10 or less is more preferable, 60/40 or less is further preferable, and 50/50 or less is particularly preferable.
上記溶媒は、また、上記非フッ素化飽和環状カーボネート、上記非フッ素化鎖状カーボネート及び上記非フッ素化鎖状カルボン酸エステルからなる群より選択される少なくとも１種を含むことも好ましく、上記非フッ素化飽和環状カーボネートと、上記非フッ素化鎖状カーボネート及び上記非フッ素化鎖状カルボン酸エステルからなる群より選択される少なくとも１種とを含むことがより好ましい。上記の組成の溶媒を含有する電解液は、比較的低電圧で使用される電気化学デバイスに好適に利用できる。 The solvent preferably also contains at least one selected from the group consisting of the non-fluorinated saturated cyclic carbonate, the non-fluorinated linear carbonate, and the non-fluorinated linear carboxylic acid ester, and the non-fluorine It is more preferable to contain a fluorinated saturated cyclic carbonate and at least one selected from the group consisting of the above non-fluorinated linear carbonate and the above non-fluorinated linear carboxylic acid ester. The electrolyte containing the solvent of the above composition can be suitably used for an electrochemical device used at a relatively low voltage.
上記溶媒が上記非フッ素化飽和環状カーボネートと、上記非フッ素化鎖状カーボネート及び上記非フッ素化鎖状カルボン酸エステルからなる群より選択される少なくとも１種とを含む場合、上記非フッ素化飽和環状カーボネートと、上記非フッ素化鎖状カーボネート及び上記非フッ素化鎖状カルボン酸エステルからなる群より選択される少なくとも１種とを合計で、５～１００体積％含むことが好ましく、２０～１００体積％含むことがより好ましく、３０～１００体積％含むことが更に好ましい。 When the solvent contains the non-fluorinated saturated cyclic carbonate and at least one selected from the group consisting of the non-fluorinated linear carbonate and the non-fluorinated linear carboxylic acid ester, the non-fluorinated saturated cyclic It is preferable that a total of 5 to 100% by volume, preferably 20 to 100% by volume, of a carbonate and at least one selected from the group consisting of the above non-fluorinated linear carbonates and the above non-fluorinated linear carboxylic acid esters It is more preferable to contain, and it is further preferable to contain 30 to 100% by volume.
上記電解液が上記非フッ素化飽和環状カーボネートと、上記非フッ素化鎖状カーボネート及び上記非フッ素化鎖状カルボン酸エステルからなる群より選択される少なくとも１種とを含む場合、上記非フッ素化飽和環状カーボネートと、上記非フッ素化鎖状カーボネート及び上記非フッ素化鎖状カルボン酸エステルからなる群より選択される少なくとも１種との体積比としては、５／９５～９５／５が好ましく、１０／９０以上がより好ましく、１５／８５以上が更に好ましく、２０／８０以上が特に好ましく、９０／１０以下がより好ましく、６０／４０以下が更に好ましく、５０／５０以下が特に好ましい。 When the electrolyte contains the non-fluorinated saturated cyclic carbonate and at least one selected from the group consisting of the non-fluorinated linear carbonate and the non-fluorinated linear carboxylic acid ester, the non-fluorinated saturation The volume ratio of the cyclic carbonate to at least one selected from the group consisting of the non-fluorinated linear carbonate and the non-fluorinated linear carboxylic acid ester is preferably 5/95 to 95/5, 10 / 90 or more is more preferable, 15/85 or more is further preferable, 20/80 or more is particularly preferable, 90/10 or less is more preferable, 60/40 or less is more preferable, 50/50 or less is particularly preferable.
上記溶媒は、また、上記フッ素化飽和環状カーボネート、上記フッ素化鎖状カーボネート及び上記フッ素化鎖状カルボン酸エステルからなる群より選択される少なくとも１種を含むことも好ましく、上記フッ素化飽和環状カーボネートと、上記フッ素化鎖状カーボネート及び上記フッ素化鎖状カルボン酸エステルからなる群より選択される少なくとも１種とを含むことがより好ましい。上記の組成の溶媒を含有する電解液は、比較的低電圧で使用される電気化学デバイスだけでなく、比較的高電圧で使用される電気化学デバイスにも好適に利用できる。 The solvent preferably also contains at least one selected from the group consisting of the fluorinated saturated cyclic carbonate, the fluorinated linear carbonate, and the fluorinated linear carboxylic acid ester, and the fluorinated saturated cyclic carbonate It is more preferable to include at least one selected from the group consisting of the fluorinated linear carbonate and the fluorinated linear carboxylic acid ester. The electrolyte containing the solvent of the above composition can be suitably used not only for electrochemical devices used at relatively low voltage but also for electrochemical devices used at relatively high voltage.
上記溶媒が上記フッ素化飽和環状カーボネートと、上記フッ素化鎖状カーボネート及び上記フッ素化鎖状カルボン酸エステルからなる群より選択される少なくとも１種とを含む場合、上記フッ素化飽和環状カーボネートと、上記フッ素化鎖状カーボネート及び上記フッ素化鎖状カルボン酸エステルからなる群より選択される少なくとも１種とを合計で、５～１００体積％含むことが好ましく、１０～１００体積％含むことがより好ましく、３０～１００体積％含むことが更に好ましい。 When the solvent contains the fluorinated saturated cyclic carbonate, and at least one selected from the group consisting of the fluorinated chain carbonate and the fluorinated chain carboxylic acid ester, the fluorinated saturated cyclic carbonate The total content of at least one selected from the group consisting of fluorinated linear carbonates and the above fluorinated linear carboxylic acid esters is preferably 5 to 100% by volume, and more preferably 10 to 100% by volume. It is more preferable to contain 30 to 100% by volume.
上記溶媒が上記フッ素化飽和環状カーボネートと、上記フッ素化鎖状カーボネート及び上記フッ素化鎖状カルボン酸エステルからなる群より選択される少なくとも１種とを含む場合、上記フッ素化飽和環状カーボネートと、上記フッ素化鎖状カーボネート及び上記フッ素化鎖状カルボン酸エステルからなる群より選択される少なくとも１種との体積比としては、５／９５～９５／５が好ましく、１０／９０以上がより好ましく、１５／８５以上が更に好ましく、２０／８０以上が特に好ましく、９０／１０以下がより好ましく、６０／４０以下が更に好ましく、５０／５０以下が特に好ましい。 When the solvent contains the fluorinated saturated cyclic carbonate, and at least one selected from the group consisting of the fluorinated chain carbonate and the fluorinated chain carboxylic acid ester, the fluorinated saturated cyclic carbonate The volume ratio to at least one selected from the group consisting of a fluorinated linear carbonate and the fluorinated linear carboxylic acid ester is preferably 5/95 to 95/5, more preferably 10/90 or more, and 15 / 85 or more is more preferable, 20/80 or more is particularly preferable, 90/10 or less is more preferable, 60/40 or less is more preferable, and 50/50 or less is particularly preferable.
また、上記溶媒として、イオン液体を用いることもできる。「イオン液体」とは、有機カチオンとアニオンとを組み合わせたイオンからなる液体である。 Moreover, an ionic liquid can also be used as said solvent. An "ionic liquid" is a liquid which consists of the ion which combined the organic cation and the anion.
有機カチオンとしては、特に限定されないが、例えば、ジアルキルイミダゾリウムカチオン、トリアルキルイミダゾリウムカチオン等のイミダゾリウムイオン；テトラアルキルアンモニウムイオン；アルキルピリジニウムイオン；ジアルキルピロリジニウムイオン；及びジアルキルピペリジニウムイオンが挙げられる。 The organic cation is not particularly limited, and examples thereof include imidazolium ions such as dialkylimidazolium cations and trialkylimidazolium cations; tetraalkylammonium ions; alkylpyridinium ions; dialkylpyrrolidinium ions; and dialkylpiperidinium ions .
これらの有機カチオンのカウンターとなるアニオンとしては、特に限定されないが、例えば、ＰＦ６アニオン、ＰＦ３（Ｃ２Ｆ５）３アニオン、ＰＦ３（ＣＦ３）３アニオン、ＢＦ４アニオン、ＢＦ２（ＣＦ３）２アニオン、ＢＦ３（ＣＦ３）アニオン、ビスオキサラトホウ酸アニオン、Ｐ（Ｃ２Ｏ４）Ｆ２アニオン、Ｔｆ（トリフルオロメタンスルホニル）アニオン、Ｎｆ（ノナフルオロブタンスルホニル）アニオン、ビス（フルオロスルホニル）イミドアニオン、ビス（トリフルオロメタンスルホニル）イミドアニオン、ビス（ペンタフルオロエタンスルホニル）イミドアニオン、ジシアノアミンアニオン、ハロゲン化物アニオンを用いることができる。 The anion serving as the counter of these organic cations is not particularly limited. For example, PF 6 anion, PF 3 (C 2 F 5 ) 3 anion, PF 3 (CF 3 ) 3 anion, BF 4 anion, BF 2 ( CF 3 ) 2 anion, BF 3 (CF 3 ) anion, bisoxalato borate anion, P (C 2 O 4 ) F 2 anion, Tf (trifluoromethanesulfonyl) anion, Nf (nonafluorobutanesulfonyl) anion, bis ( A fluorosulfonyl) imide anion, a bis (trifluoromethanesulfonyl) imide anion, a bis (pentafluoroethanesulfonyl) imide anion, a dicyanoamine anion, and a halide anion can be used.
上記溶媒は、非水溶媒であることが好ましく、本発明の電解液は、非水電解液であることが好ましい。 The solvent is preferably a non-aqueous solvent, and the electrolytic solution of the present invention is preferably a non-aqueous electrolytic solution.
本発明の電解液は、更に、一般式（５）で示される化合物（５）を含んでもよい。 The electrolytic solution of the present invention may further contain a compound (5) represented by the general formula (5).
一般式（５）：
Figure JPOXMLDOC01-appb-C000048
 （式中、Ａａ＋は金属イオン、水素イオン又はオニウムイオン。ａは１～３の整数、ｂは１～３の整数、ｐはｂ／ａ、ｎ２０３は１～４の整数、ｎ２０１は０～８の整数、ｎ２０２は０又は１、Ｚ２０１は遷移金属、周期律表のＩＩＩ族、ＩＶ族又はＶ族の元素。
Ｘ２０１は、Ｏ、Ｓ、炭素数１～１０のアルキレン基、炭素数１～１０のハロゲン化アルキレン基、炭素数６～２０のアリーレン基又は炭素数６～２０のハロゲン化アリーレン基（アルキレン基、ハロゲン化アルキレン基、アリーレン基、及び、ハロゲン化アリーレン基はその構造中に置換基、ヘテロ原子を持っていてもよく、またｎ２０２が１でｎ２０３が２～４のときにはｎ２０３個のＸ２０１はそれぞれが結合していてもよい）。
Ｌ２０１は、ハロゲン原子、シアノ基、炭素数１～１０のアルキル基、炭素数１～１０のハロゲン化アルキル基、炭素数６～２０のアリール基、炭素数６～２０のハロゲン化アリール基（アルキレン基、ハロゲン化アルキレン基、アリーレン基、及び、ハロゲン化アリーレン基はその構造中に置換基、ヘテロ原子を持っていてもよく、またｎ２０１が２～８のときにはｎ２０１個のＬ２０１はそれぞれが結合して環を形成してもよい）又は－Ｚ２０３Ｙ２０３。
Ｙ２０１、Ｙ２０２及びＺ２０３は、それぞれ独立でＯ、Ｓ、ＮＹ２０４、炭化水素基又はフッ素化炭化水素基。Ｙ２０３及びＹ２０４は、それぞれ独立でＨ、Ｆ、炭素数１～１０のアルキル基、炭素数１～１０のハロゲン化アルキル基、炭素数６～２０のアリール基又は炭素数６～２０のハロゲン化アリール基（アルキル基、ハロゲン化アルキル基、アリール基及びハロゲン化アリール基はその構造中に置換基、ヘテロ原子を持っていてもよく、Ｙ２０３又はＹ２０４が複数個存在する場合にはそれぞれが結合して環を形成してもよい）。） General formula (5):
Figure JPOXMLDOC01-appb-C000048
 (Wherein, A a + is a metal ion, a hydrogen ion or an onium ion, a is an integer of 1 to 3, b is an integer of 1 to 3, p is b / a, n 203 is an integer of 1 to 4, n 201 is An integer of 0 to 8, n 202 is 0 or 1, Z 201 is a transition metal, an element of group III, IV or V of the periodic table.
X 201 represents O, S, an alkylene group having 1 to 10 carbon atoms, a halogenated alkylene group having 1 to 10 carbon atoms, an arylene group having 6 to 20 carbon atoms, or a halogenated arylene group having 6 to 20 carbon atoms (alkylene group And the halogenated alkylene group, the arylene group and the halogenated arylene group may have a substituent or a hetero atom in the structure, and when n 202 is 1 and n 203 is 2 to 4, n 203 Each X 201 may be bonded).
L 201 represents a halogen atom, a cyano group, an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms, a halogenated aryl group having 6 to 20 carbon atoms The alkylene group, the halogenated alkylene group, the arylene group and the halogenated arylene group may have a substituent or a hetero atom in the structure, and when n 201 is 2 to 8, n 201 L 201 is Each may combine to form a ring) or -Z 203 Y 203 .
Y 201, Y 202 and Z 203 are, O each independently, S, NY 204, hydrocarbon group or a fluorinated hydrocarbon group. Y 203 and Y 204 each independently represent H, F, an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms or a halogen having 6 to 20 carbon atoms Arylated aryl group (the alkyl group, the halogenated alkyl group, the aryl group and the halogenated aryl group may have a substituent or a hetero atom in the structure, and when a plurality of Y 203 or Y 204 exist, May combine to form a ring). )
Ａａ＋としては、リチウムイオン、ナトリウムイオン、カリウムイオン、マグネシウムイオン、カルシウムイオン、バリウムイオン、セシウムイオン、銀イオン、亜鉛イオン、銅イオン、コバルトイオン、鉄イオン、ニッケルイオン、マンガンイオン、チタンイオン、鉛イオン、クロムイオン、バナジウムイオン、ルテニウムイオン、イットリウムイオン、ランタノイドイオン、アクチノイドイオン、テトラブチルアンモニウムイオン、テトラエチルアンモニウムイオン、テトラメチルアンモニウムイオン、トリエチルメチルアンモニウムイオン、トリエチルアンモニウムイオン、ピリジニウムイオン、イミダゾリウムイオン、水素イオン、テトラエチルホスホニウムイオン、テトラメチルホスホニウムイオン、テトラフェニルホスホニウムイオン、トリフェニルスルホニウムイオン、トリエチルスルホニウムイオン等が挙げられる。 As A a + , lithium ion, sodium ion, potassium ion, magnesium ion, calcium ion, barium ion, cesium ion, silver ion, zinc ion, copper ion, cobalt ion, iron ion, nickel ion, manganese ion, titanium ion, Lead ion, chromium ion, vanadium ion, ruthenium ion, yttrium ion, lanthanide ion, actinide ion, tetrabutyl ammonium ion, tetraethyl ammonium ion, tetramethyl ammonium ion, triethyl methyl ammonium ion, triethyl ammonium ion, pyridinium ion, imidazolium ion , Hydrogen ion, tetraethyl phosphonium ion, tetramethyl phosphonium ion, tetraphenyl phosphonium Ions, triphenylsulfonium ion, triethylsulfonium ion and the like.
電気化学的なデバイス等の用途に使用する場合、Ａａ＋は、リチウムイオン、ナトリウムイオン、マグネシウムイオン、テトラアルキルアンモニウムイオン、水素イオンが好ましく、リチウムイオンが特に好ましい。Ａａ＋のカチオンの価数ａは、１～３の整数である。３より大きい場合、結晶格子エネルギーが大きくなるため、溶媒に溶解することが困難になるという問題が起こる。そのため溶解度を必要とする場合は１がより好ましい。アニオンの価数ｂも同様に１～３の整数であり、特に１が好ましい。カチオンとアニオンの比を表す定数ｐは、両者の価数の比ｂ／ａで必然的に決まる。 When used for applications such as electrochemical devices, A a + is preferably a lithium ion, a sodium ion, a magnesium ion, a tetraalkylammonium ion or a hydrogen ion, and a lithium ion is particularly preferable. The valence number a of the cation of A a + is an integer of 1 to 3. If it is more than 3, the crystal lattice energy becomes large, which causes a problem that dissolution in a solvent becomes difficult. Therefore, when solubility is required, 1 is more preferable. Likewise, the valence b of the anion is an integer of 1 to 3, and 1 is particularly preferable. The constant p representing the ratio of cation to anion is necessarily determined by the ratio b / a of the two valences.
次に、一般式（５）の配位子の部分について説明する。本明細書において、一般式（５）におけるＺ２０１に結合している有機又は無機の部分を配位子と呼ぶ。 Next, the ligand part of the general formula (5) will be described. In the present specification, the organic or inorganic moiety bonded to Z 201 in the general formula (5) is referred to as a ligand.
Ｚ２０１は、Ａｌ、Ｂ、Ｖ、Ｔｉ、Ｓｉ、Ｚｒ、Ｇｅ、Ｓｎ、Ｃｕ、Ｙ、Ｚｎ、Ｇａ、Ｎｂ、Ｔａ、Ｂｉ、Ｐ、Ａｓ、Ｓｃ、Ｈｆ又はＳｂであることが好ましく、Ａｌ、Ｂ又はＰであることがより好ましい。 Z 201 is preferably Al, B, V, Ti, Si, Zr, Ge, Sn, Cu, Y, Zn, Ga, Nb, Ta, Bi, P, As, Sc, Hf or Sb, Al , B or P is more preferable.
Ｘ２０１は、Ｏ、Ｓ、炭素数１～１０のアルキレン基、炭素数１～１０のハロゲン化アルキレン基、炭素数６～２０のアリーレン基又は炭素数６～２０のハロゲン化アリーレン基を表す。これらのアルキレン基及びアリーレン基はその構造中に置換基、ヘテロ原子を持っていてもよい。具体的には、アルキレン基及びアリーレン基上の水素の代わりに、ハロゲン原子、鎖状又は環状のアルキル基、アリール基、アルケニル基、アルコキシ基、アリーロキシ基、スルホニル基、アミノ基、シアノ基、カルボニル基、アシル基、アミド基、水酸基を置換基として持っていてもよいし、アルキレン及びアリーレン上の炭素の代わりに、窒素、硫黄、酸素が導入された構造であってもよい。またｎ２０２が１でｎ２０３が２～４のときには、ｎ２０３個のＸ２０１はそれぞれが結合していてもよい。そのような例としては、エチレンジアミン四酢酸のような配位子を挙げることができる。 X 201 represents O, S, an alkylene group having 1 to 10 carbon atoms, a halogenated alkylene group having 1 to 10 carbon atoms, an arylene group having 6 to 20 carbon atoms, or a halogenated arylene group having 6 to 20 carbon atoms. These alkylene group and arylene group may have a substituent or a hetero atom in the structure. Specifically, instead of hydrogen on an alkylene group and an arylene group, a halogen atom, a chain or cyclic alkyl group, an aryl group, an alkenyl group, an alkoxy group, an aryloxy group, a sulfonyl group, an amino group, a cyano group, a carbonyl It may have a group, an acyl group, an amido group or a hydroxyl group as a substituent, or may have a structure in which nitrogen, sulfur or oxygen is introduced instead of carbon on alkylene and arylene. When n 202 is 1 and n 203 is 2 to 4, each of n 203 X 201 may be combined. Such examples may include ligands such as ethylenediaminetetraacetic acid.
Ｌ２０１は、ハロゲン原子、シアノ基、炭素数１～１０のアルキル基、炭素数１～１０のハロゲン化アルキル基、炭素数６～２０のアリール基、炭素数６～２０のハロゲン化アリール基又は－Ｚ２０３Ｙ２０３（Ｚ２０３、Ｙ２０３については後述）を表す。ここでのアルキル基及びアリール基も、Ｘ２０１と同様に、その構造中に置換基、ヘテロ原子を持っていてもよく、またｎ２０１が２～８のときにはｎ２０１個のＬ２０１はそれぞれが結合して環を形成していてもよい。Ｌ２０１としては、フッ素原子又はシアノ基が好ましい。フッ素原子の場合には、アニオン化合物の塩の溶解度や解離度が向上し、これに伴ってイオン伝導度が向上するからである。また、耐酸化性が向上し、これにより副反応の発生を抑制することができるからである。 L 201 represents a halogen atom, a cyano group, an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms, a halogenated aryl group having 6 to 20 carbon atoms, -Z 203 Y 203 (Z 203 and Y 203 will be described later). The alkyl group and the aryl group here may also have a substituent and a hetero atom in the structure, as in X 201, and when n 201 is 2 to 8, n 201 L 201 is each It may combine to form a ring. As L 201 , a fluorine atom or a cyano group is preferable. In the case of a fluorine atom, the solubility and the degree of dissociation of the salt of the anion compound are improved, and along with this, the ion conductivity is improved. Moreover, it is because oxidation resistance improves and generation | occurrence | production of a side reaction can be suppressed by this.
Ｙ２０１、Ｙ２０２及びＺ２０３は、それぞれ独立で、Ｏ、Ｓ、ＮＹ２０４、炭化水素基又はフッ素化炭化水素基を表す。Ｙ２０１及びＹ２０２は、Ｏ、Ｓ又はＮＹ２０４であることが好ましく、Ｏであることがより好ましい。化合物（５）の特徴として、同一の配位子内にＹ２０１及びＹ２０２によるＺ２０１との結合があるため、これらの配位子がＺ２０１とキレート構造を構成している。このキレートの効果により、この化合物の耐熱性、化学的安定性、耐加水分解性が向上している。この配位子中の定数ｎ２０２は０又は１であるが、特に、０の場合はこのキレートリングが五員環になるため、キレート効果が最も強く発揮され安定性が増すため好ましい。
なお、本明細書において、フッ素化炭化水素基は、炭化水素基の水素原子の少なくとも１つがフッ素原子に置換された基である。 Y 201, Y 202 and Z 203 are each independently, O, S, NY 204, hydrocarbon group, or an fluorinated hydrocarbon group. Y 201 and Y 202 are preferably O, S or NY 204 , more preferably O. As a feature of the compound (5), because of the coupling with Z 201 by Y 201 and Y 202, these ligands constitute the Z 201 and chelate structure within the same ligand. The heat resistance, chemical stability and hydrolysis resistance of this compound are improved by the effect of this chelate. The constant n 202 in this ligand is 0 or 1, but in the case of 0, in particular, the chelating effect is a five-membered ring, and thus the chelating effect is most strongly exhibited and the stability is increased.
In the present specification, a fluorinated hydrocarbon group is a group in which at least one hydrogen atom of a hydrocarbon group is substituted by a fluorine atom.
Ｙ２０３及びＹ２０４は、それぞれ独立で、Ｈ、Ｆ、炭素数１～１０のアルキル基、炭素数１～１０のハロゲン化アルキル基、炭素数６～２０のアリール基又は炭素数６～２０のハロゲン化アリール基であり、これらのアルキル基及びアリール基は、その構造中に置換基又はヘテロ原子を有してもよく、またＹ２０３又はＹ２０４が複数個存在する場合には、それぞれが結合して環を形成してもよい。 Y 203 and Y 204 each independently represent H, F, an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms, or 6 to 20 carbon atoms It is a halogenated aryl group, and these alkyl group and aryl group may have a substituent or a hetero atom in the structure, and when two or more Y 203 or Y 204 exist, each is bonded To form a ring.
また、上述した配位子の数に関係する定数ｎ２０３は、１～４の整数であり、好ましくは１又は２であり、より好ましくは２である。また、上述した配位子の数に関係する定数ｎ２０１は、０～８の整数であり、好ましくは０～４の整数であり、より好ましくは０、２又は４である。更に、ｎ２０３が１のときｎ２０１は２、ｎ２０３が２のときｎ２０１は０であることが好ましい。 The constant n 203 related to the number of ligands described above is an integer of 1 to 4, preferably 1 or 2, and more preferably 2. The constant n 201 related to the number of ligands described above is an integer of 0 to 8, preferably an integer of 0 to 4, and more preferably 0, 2 or 4. Furthermore, it is preferable that n 201 is 2 when n 203 is 1 and n 201 is 0 when n 203 is 2.
一般式（５）において、アルキル基、ハロゲン化アルキル基、アリール基、ハロゲン化アリール基は、分岐や水酸基、エーテル結合等の他の官能基を持つものも含む。 In the general formula (5), the alkyl group, the halogenated alkyl group, the aryl group and the halogenated aryl group also include those having other functional groups such as a branch, a hydroxyl group and an ether bond.
化合物（５）としては、一般式：
Figure JPOXMLDOC01-appb-C000049
 （式中、Ａａ＋、ａ、ｂ、ｐ、ｎ２０１、Ｚ２０１及びＬ２０１は上述したとおり）で示される化合物、又は、一般式：
Figure JPOXMLDOC01-appb-C000050
 （式中、Ａａ＋、ａ、ｂ、ｐ、ｎ２０１、Ｚ２０１及びＬ２０１は上述したとおり）で示される化合物であることが好ましい。 As the compound (5), a compound represented by the general formula:
Figure JPOXMLDOC01-appb-C000049
 ( Wherein , a a + , a, b, p, n 201 , Z 201 and L 201 are as described above) or a compound represented by the general formula:
Figure JPOXMLDOC01-appb-C000050
 (Wherein, A a + , a, b, p, n 201 , Z 201 and L 201 are as described above) is preferable.
化合物（５）としては、リチウムオキサラトボレート塩類が挙げられ、下記式：
Figure JPOXMLDOC01-appb-C000051
 で示されるリチウムビス（オキサラト）ボレート（ＬＩＢＯＢ）、下記式：
Figure JPOXMLDOC01-appb-C000052
 で示されるリチウムジフルオロオキサラトボレート（ＬＩＤＦＯＢ）、 Examples of the compound (5) include lithium oxalato borate salts, and the following formula:
Figure JPOXMLDOC01-appb-C000051
 Lithium bis (oxalato) borate (LIBOB) represented by the following formula:
Figure JPOXMLDOC01-appb-C000052
 Lithium difluoro oxalato borate (LIDFOB),
化合物（５）としては、また、下記式：
Figure JPOXMLDOC01-appb-C000053
 で示されるリチウムジフルオロオキサラトホスファナイト（ＬＩＤＦＯＰ）、下記式：
Figure JPOXMLDOC01-appb-C000054
 で示されるリチウムテトラフルオロオキサラトホスファナイト（ＬＩＴＦＯＰ）、下記式：
Figure JPOXMLDOC01-appb-C000055
 で示されるリチウムビス（オキサラト）ジフルオロホスファナイト等が挙げられる。 As the compound (5), the following formula:
Figure JPOXMLDOC01-appb-C000053
 Lithium difluoro oxalato phosphanite (LIDFOP) represented by the following formula:
Figure JPOXMLDOC01-appb-C000054
 Lithium tetrafluoro oxalato phosphanite (LITFOP) represented by the following formula:
Figure JPOXMLDOC01-appb-C000055
 And lithium bis (oxalato) difluorophosphanite and the like.
その他、錯体中心元素がホウ素であるジカルボン酸錯体塩の具体例としては、リチウムビス（マロナト）ボレート、リチウムジフルオロ（マロナト）ボレート、リチウムビス（メチルマロナト）ボレート、リチウムジフルオロ（メチルマロナト）ボレート、リチウムビス（ジメチルマロナト）ボレート、リチウムジフルオロ（ジメチルマロナト）ボレート等が挙げられる。 Other specific examples of dicarboxylic acid complex salts in which the complex center element is boron include lithium bis (malonato) borate, lithium difluoro (malonato) borate, lithium bis (methyl malonato) borate, lithium difluoro (methyl malonato) borate, lithium bis ( Dimethyl malonato) borate, lithium difluoro (dimethyl malonato) borate and the like can be mentioned.
錯体中心元素がリンであるジカルボン酸錯体塩の具体例としては、リチウムトリス（オキサラト）ホスフェート、リチウムトリス（マロナト）ホスフェート、リチウムジフルオロビス（マロナト）ホスフェート、リチウムテトラフルオロ（マロナト）ホスフェート、リチウムトリス（メチルマロナト）ホスフェート、リチウムジフルオロビス（メチルマロナト）ホスフェート、リチウムテトラフルオロ（メチルマロナト）ホスフェート、リチウムトリス（ジメチルマロナト）ホスフェート、リチウムジフルオロビス（ジメチルマロナト）ホスフェート、リチウムテトラフルオロ（ジメチルマロナト）ホスフェート等が挙げられる。 Specific examples of the dicarboxylic acid complex salt in which the complex central element is phosphorus include lithium tris (oxalato) phosphate, lithium tris (malonato) phosphate, lithium difluorobis (malonato) phosphate, lithium tetrafluoro (malonato) phosphate and lithium tris Methylmalonato) phosphate, lithium difluorobis (methylmalonato) phosphate, lithium tetrafluoro (methylmalonato) phosphate, lithium tris (dimethylmalonato) phosphate, lithium difluorobis (dimethylmalonato) phosphate, lithium tetrafluoro (dimethylmalonato) phosphate etc. It can be mentioned.
錯体中心元素がアルミニウムであるジカルボン酸錯体塩の具体例としては、ＬｉＡｌ（Ｃ２Ｏ４）２、ＬｉＡｌＦ２（Ｃ２Ｏ４）等が挙げられる。 As a specific example of the dicarboxylic acid complex salt whose complex central element is aluminum, LiAl (C 2 O 4 ) 2 , LiAlF 2 (C 2 O 4 ), etc. may be mentioned.
中でも、リチウムビス（オキサラト）ボレート、リチウムジフルオロ（オキサラト）ボレート、リチウムトリス（オキサラト）ホスフェート、リチウムジフルオロビス（オキサラト）ホスフェート、リチウムテトラフルオロ（オキサラト）ホスフェートが、入手の容易さや安定な被膜状の構造物の形成に寄与することができる点から、より好適に用いられる。化合物（５）としては、リチウムビス（オキサラト）ボレートが特に好ましい。 Among them, lithium bis (oxalato) borate, lithium difluoro (oxalato) borate, lithium tris (oxalato) phosphate, lithium difluorobis (oxalato) phosphate and lithium tetrafluoro (oxalato) phosphate are easy to obtain and have a stable film-like structure. From the point which can contribute to formation of a thing, it is used more suitably. As the compound (5), lithium bis (oxalato) borate is particularly preferable.
化合物（５）の含有量としては、より一層の優れたサイクル特性が得られることから、上記溶媒に対して、０．００１質量％以上が好ましく、０．０１質量％以上がより好ましく、１０質量％以下が好ましく、３質量％以下がより好ましい。 The content of the compound (5) is preferably 0.001% by mass or more, more preferably 0.01% by mass or more, and 10% by mass, with respect to the solvent, since further excellent cycle characteristics can be obtained. % Or less is preferable and 3 mass% or less is more preferable.
本発明の電解液は、更に、電解質塩（但し、化合物（５）を除く）を含むことが好ましい。上記電解質塩としては、リチウム塩、アンモニウム塩、金属塩のほか、液体状の塩（イオン性液体）、無機高分子型の塩、有機高分子型の塩等、電解液に使用することができる任意のものを用いることができる。 The electrolytic solution of the present invention preferably further contains an electrolyte salt (except for the compound (5)). As the electrolyte salt, in addition to lithium salt, ammonium salt, metal salt, liquid salt (ionic liquid), inorganic polymer type salt, organic polymer type salt, etc. can be used for electrolyte solution Any thing can be used.
リチウムイオン二次電池用電解液の電解質塩としては、リチウム塩が好ましい。
上記リチウム塩として任意のものを用いることができ、具体的には以下のものが挙げられる。例えば、ＬｉＰＦ６、ＬｉＢＦ４、ＬｉＣｌＯ４、ＬｉＡｌＦ４、ＬｉＳｂＦ６、ＬｉＴａＦ６、ＬｉＷＦ７、ＬｉＡｓＦ６，ＬｉＡｌＣｌ４，ＬｉＩ、ＬｉＢｒ、ＬｉＣｌ、ＬｉＢ１０Ｃｌ１０、Ｌｉ２ＳｉＦ６、Ｌｉ２ＰＦＯ３、ＬｉＰＯ２Ｆ２等の無機リチウム塩；
ＬｉＷＯＦ５等のタングステン酸リチウム類；
ＨＣＯ２Ｌｉ、ＣＨ３ＣＯ２Ｌｉ、ＣＨ２ＦＣＯ２Ｌｉ、ＣＨＦ２ＣＯ２Ｌｉ、ＣＦ３ＣＯ２Ｌｉ、ＣＦ３ＣＨ２ＣＯ２Ｌｉ、ＣＦ３ＣＦ２ＣＯ２Ｌｉ、ＣＦ３ＣＦ２ＣＦ２ＣＯ２Ｌｉ、ＣＦ３ＣＦ２ＣＦ２ＣＦ２ＣＯ２Ｌｉ等のカルボン酸リチウム塩類；
ＦＳＯ３Ｌｉ、ＣＨ３ＳＯ３Ｌｉ、ＣＨ２ＦＳＯ３Ｌｉ、ＣＨＦ２ＳＯ３Ｌｉ、ＣＦ３ＳＯ３Ｌｉ、ＣＦ３ＣＦ２ＳＯ３Ｌｉ、ＣＦ３ＣＦ２ＣＦ２ＳＯ３Ｌｉ、ＣＦ３ＣＦ２ＣＦ２ＣＦ２ＳＯ３Ｌｉ、リチウムメチルサルフェート、リチウムエチルサルフェート（Ｃ２Ｈ５ＯＳＯ３Ｌｉ）、リチウム２，２，２－トリフルオロエチルサルフェート等のＳ＝Ｏ基を有するリチウム塩類；
ＬｉＮ（ＦＣＯ）２、ＬｉＮ（ＦＣＯ）（ＦＳＯ２）、ＬｉＮ（ＦＳＯ２）２、ＬｉＮ（ＦＳＯ２）（ＣＦ３ＳＯ２）、ＬｉＮ（ＣＦ３ＳＯ２）２、ＬｉＮ（Ｃ２Ｆ５ＳＯ２）２、リチウムビスパーフルオロエタンスルホニルイミド、リチウム環状１，２－パーフルオロエタンジスルホニルイミド、リチウム環状１，３－パーフルオロプロパンジスルホニルイミド、リチウム環状１，２－エタンジスルホニルイミド、リチウム環状１，３－プロパンジスルホニルイミド、リチウム環状１，４－パーフルオロブタンジスルホニルイミド、ＬｉＮ（ＣＦ３ＳＯ２）（ＦＳＯ２）、ＬｉＮ（ＣＦ３ＳＯ２）（Ｃ３Ｆ７ＳＯ２）、ＬｉＮ（ＣＦ３ＳＯ２）（Ｃ４Ｆ９ＳＯ２）、ＬｉＮ（ＰＯＦ２）２等のリチウムイミド塩類；
ＬｉＣ（ＦＳＯ２）３、ＬｉＣ（ＣＦ３ＳＯ２）３、ＬｉＣ（Ｃ２Ｆ５ＳＯ２）３等のリチウムメチド塩類；
その他、式：ＬｉＰＦａ（ＣｎＦ２ｎ＋１）６－ａ（式中、ａは０～５の整数であり、ｎは１～６の整数である）で表される塩（例えばＬｉＰＦ３（Ｃ２Ｆ５）３、ＬｉＰＦ３（ＣＦ３）３、ＬｉＰＦ３（ｉｓｏ－Ｃ３Ｆ７）３、ＬｉＰＦ５（ｉｓｏ－Ｃ３Ｆ７）、ＬｉＰＦ４（ＣＦ３）２、ＬｉＰＦ４（Ｃ２Ｆ５）２）、ＬｉＰＦ４（ＣＦ３ＳＯ２）２、ＬｉＰＦ４（Ｃ２Ｆ５ＳＯ２）２、ＬｉＢＦ３ＣＦ３、ＬｉＢＦ３Ｃ２Ｆ５、ＬｉＢＦ３Ｃ３Ｆ７、ＬｉＢＦ２（ＣＦ３）２、ＬｉＢＦ２（Ｃ２Ｆ５）２、ＬｉＢＦ２（ＣＦ３ＳＯ２）２、ＬｉＢＦ２（Ｃ２Ｆ５ＳＯ２）２等の含フッ素有機リチウム塩類；ＬｉＳＣＮ、ＬｉＢ（ＣＮ）４、ＬｉＢ（Ｃ６Ｈ５）４、Ｌｉ２（Ｃ２Ｏ４）、ＬｉＰ（Ｃ２Ｏ４）３、Ｌｉ２Ｂ１２ＦｂＨ１２－ｂ（ｂは０～３の整数）等が挙げられる。 As an electrolyte salt of the electrolyte solution for lithium ion secondary batteries, lithium salt is preferable.
Arbitrary things can be used as said lithium salt, The following are mentioned specifically. For example, LiPF 6, LiBF 4, LiClO 4, LiAlF 4, LiSbF 6, LiTaF 6, LiWF 7, LiAsF 6, LiAlCl 4, LiI, LiBr, LiCl, LiB 10 Cl 10, Li 2 SiF 6, Li 2 PFO 3, Inorganic lithium salts such as LiPO 2 F 2 ;
Lithium tungstates such as LiWOF 5 ;
HCO 2 Li, CH 3 CO 2 Li, CH 2 FCO 2 Li, CHF 2 CO 2 Li, CF 3 CO 2 Li, CF 3 CH 2 CO 2 Li, CF 3 CF 2 CO 2 Li, CF 3 CF 2 CF 2 Carboxylic acid lithium salts such as CO 2 Li, CF 3 CF 2 CF 2 CF 2 CO 2 Li;
FSO 3 Li, CH 3 SO 3 Li, CH 2 FSO 3 Li, CHF 2 SO 3 Li, CF 3 SO 3 Li, CF 3 CF 2 SO 3 Li, CF 3 CF 2 CF 2 SO 3 Li, CF 3 CF 2 Lithium salts having an S = O group such as CF 2 CF 2 SO 3 Li, lithium methyl sulfate, lithium ethyl sulfate (C 2 H 5 OSO 3 Li), lithium 2,2,2-trifluoroethyl sulfate, etc .;
LiN (FCO) 2, LiN ( FCO) (FSO 2), LiN (FSO 2) 2, LiN (FSO 2) (CF 3 SO 2), LiN (CF 3 SO 2) 2, LiN (C 2 F 5 SO 2 ) 2 , lithium bisperfluoroethane sulfonylimide, lithium cyclic 1,2-perfluoroethanedisulfonylimide, lithium cyclic 1,3-perfluoropropane disulfonylimide, lithium cyclic 1,2-ethanedisulfonylimide, lithium cyclic 1,3-propanediol disulfonylimide, lithium cyclic 1,4-perfluorobutane disulfonylimide, LiN (CF 3 SO 2) (FSO 2), LiN (CF 3 SO 2) (C 3 F 7 SO 2) , LiN (CF 3 SO 2) (C 4 F 9 SO 2), LiN (POF 2) 2 and the like lithium in Muimido salts;
Lithium methide salts such as LiC (FSO 2 ) 3 , LiC (CF 3 SO 2 ) 3 , LiC (C 2 F 5 SO 2 ) 3 and the like;
In addition, a salt represented by the formula: LiPF a (C n F 2 n + 1 ) 6-a (wherein, a is an integer of 0 to 5 and n is an integer of 1 to 6) (eg LiPF 3 (C 2 F 5 ) 3 , LiPF 3 (CF 3 ) 3 , LiPF 3 (iso-C 3 F 7 ) 3 , LiPF 5 (iso-C 3 F 7 ), LiPF 4 (CF 3 ) 2 , LiPF 4 (C 2 F 5 ) 2 ), LiPF 4 (CF 3 SO 2 ) 2 , LiPF 4 (C 2 F 5 SO 2 ) 2 , LiBF 3 CF 3 , LiBF 3 C 2 F 5 , LiBF 3 C 3 F 7 , LiBF 2 ( Fluorine-containing organic lithium salts such as CF 3 ) 2 , LiBF 2 (C 2 F 5 ) 2 , LiBF 2 (CF 3 SO 2 ) 2 , LiBF 2 (C 2 F 5 SO 2 ) 2 ; LiSCN, LiB (CN) 4, LiB ( 6 H 5) 4, Li 2 (C 2 O 4), LiP (C 2 O 4) 3, Li 2 B 12 F b H 12-b (b can be mentioned an integer of 0 to 3), or the like.
中でも、ＬｉＰＦ６、ＬｉＢＦ４、ＬｉＳｂＦ６、ＬｉＴａＦ６、ＬｉＰＯ２Ｆ２、ＦＳＯ３Ｌｉ、ＣＦ３ＳＯ３Ｌｉ、ＬｉＮ（ＦＳＯ２）２、ＬｉＮ（ＦＳＯ２）（ＣＦ３ＳＯ２）、ＬｉＮ（ＣＦ３ＳＯ２）２、ＬｉＮ（Ｃ２Ｆ５ＳＯ２）２、リチウム環状１，２－パーフルオロエタンジスルホニルイミド、リチウム環状１，３－パーフルオロプロパンジスルホニルイミド、ＬｉＣ（ＦＳＯ２）３、ＬｉＣ（ＣＦ３ＳＯ２）３、ＬｉＣ（Ｃ２Ｆ５ＳＯ２）３、ＬｉＢＦ３ＣＦ３、ＬｉＢＦ３Ｃ２Ｆ５、ＬｉＰＦ３（ＣＦ３）３、ＬｉＰＦ３（Ｃ２Ｆ５）３等が出力特性やハイレート充放電特性、高温保存特性、サイクル特性等を向上させる効果がある点から特に好ましく、ＬｉＰＦ６、ＬｉＮ（ＦＳＯ２）２及びＬｉＢＦ４からなる群より選択される少なくとも１種のリチウム塩が最も好ましい。 Among them, LiPF 6 , LiBF 4 , LiSbF 6 , LiTaF 6 , LiPO 2 F 2 , FSO 3 Li, CF 3 SO 3 Li, LiN (FSO 2 ) 2 , LiN (FSO 2 ) (CF 3 SO 2 ), LiN (Li 3 CF 3 SO 2 ) 2 , LiN (C 2 F 5 SO 2 ) 2 , lithium cyclic 1,2-perfluoroethane disulfonylimide, lithium cyclic 1,3-perfluoropropane disulfonyl imide, LiC (FSO 2 ) 3 , LiC (CF 3 SO 2) 3, LiC (C 2 F 5 SO 2) 3, LiBF 3 CF 3, LiBF 3 C 2 F 5, LiPF 3 (CF 3) 3, LiPF 3 (C 2 F 5) 3 Is particularly preferable because it has the effect of improving output characteristics, high rate charge / discharge characteristics, high temperature storage characteristics, cycle characteristics etc. F 6, LiN (FSO 2) 2 and at least one lithium salt selected from the group consisting of LiBF 4 are most preferred.
これらの電解質塩は単独で用いても、２種以上を併用してもよい。２種以上を併用する場合の好ましい一例は、ＬｉＰＦ６とＬｉＢＦ４との併用や、ＬｉＰＦ６とＬｉＰＯ２Ｆ２、Ｃ２Ｈ５ＯＳＯ３Ｌｉ又はＦＳＯ３Ｌｉとの併用であり、高温保存特性、負荷特性やサイクル特性を向上させる効果がある。 These electrolyte salts may be used alone or in combination of two or more. A preferable example in the case of using two or more in combination is a combined use of LiPF 6 and LiBF 4 or a combined use of LiPF 6 and LiPO 2 F 2 , C 2 H 5 OSO 3 Li or FSO 3 Li, and the high temperature storage characteristics There is an effect of improving load characteristics and cycle characteristics.
この場合、電解液全体１００質量％に対するＬｉＢＦ４、ＬｉＰＯ２Ｆ２、Ｃ２Ｈ５ＯＳＯ３Ｌｉ又はＦＳＯ３Ｌｉの配合量に制限は無く、本発明の効果を著しく損なわない限り任意であるが、本発明の電解液に対して、通常、０．０１質量％以上、好ましくは０．１質量％以上であり、また、通常３０質量％以下、好ましくは２０質量％以下、より好ましくは１０質量％以下、更に好ましくは５質量％以下である。 In this case, the blending amount of LiBF 4 , LiPO 2 F 2 , C 2 H 5 OSO 3 Li or FSO 3 Li with respect to 100% by mass of the whole electrolyte solution is not limited, and is optional unless the effects of the present invention are significantly impaired. The amount is usually 0.01% by mass or more, preferably 0.1% by mass or more, and usually 30% by mass or less, preferably 20% by mass or less, more preferably 10% by mass, with respect to the electrolytic solution of the present invention. % Or less, more preferably 5% by mass or less.
また、他の一例は、無機リチウム塩と有機リチウム塩との併用であり、この両者の併用は、高温保存による劣化を抑制する効果がある。有機リチウム塩としては、ＣＦ３ＳＯ３Ｌｉ、ＬｉＮ（ＦＳＯ２）２、ＬｉＮ（ＦＳＯ２）（ＣＦ３ＳＯ２）、ＬｉＮ（ＣＦ３ＳＯ２）２、ＬｉＮ（Ｃ２Ｆ５ＳＯ２）２、リチウム環状１，２－パーフルオロエタンジスルホニルイミド、リチウム環状１，３－パーフルオロプロパンジスルホニルイミド、ＬｉＣ（ＦＳＯ２）３、ＬｉＣ（ＣＦ３ＳＯ２）３、ＬｉＣ（Ｃ２Ｆ５ＳＯ２）３、ＬｉＢＦ３ＣＦ３、ＬｉＢＦ３Ｃ２Ｆ５、ＬｉＰＦ３（ＣＦ３）３、ＬｉＰＦ３（Ｃ２Ｆ５）３等であるのが好ましい。この場合には、電解液全体１００質量％に対する有機リチウム塩の割合は、好ましくは０．１質量％以上、特に好ましくは０．５質量％以上であり、また、好ましくは３０質量％以下、特に好ましくは２０質量％以下である。 Another example is the combined use of an inorganic lithium salt and an organic lithium salt, and the combined use of both has the effect of suppressing deterioration due to high temperature storage. As the organic lithium salt, CF 3 SO 3 Li, LiN (FSO 2 ) 2 , LiN (FSO 2 ) (CF 3 SO 2 ), LiN (CF 3 SO 2 ) 2 , LiN (C 2 F 5 SO 2 ) 2 Lithium cyclic 1,2-perfluoroethanedisulfonyl imide lithium cyclic 1,3-perfluoropropane disulfonyl imide LiC (FSO 2 ) 3 LiC (CF 3 SO 2 ) 3 LiC (C 2 F 5 SO 2 ) 2 ) 3 , LiBF 3 CF 3 , LiBF 3 C 2 F 5 , LiPF 3 (CF 3 ) 3 , LiPF 3 (C 2 F 5 ) 3 or the like. In this case, the ratio of the organic lithium salt to the total 100% by mass of the electrolyte is preferably 0.1% by mass or more, particularly preferably 0.5% by mass or more, and preferably 30% by mass or less, particularly preferably Preferably it is 20 mass% or less.
電解液中のこれらの電解質塩の濃度は、本発明の効果を損なわない限り特に制限されない。電解液の電気伝導率を良好な範囲とし、良好な電池性能を確保する点から、電解液中のリチウムの総モル濃度は、好ましくは０．３ｍｏｌ／Ｌ以上、より好ましくは０．４ｍｏｌ／Ｌ以上、更に好ましくは０．５ｍｏｌ／Ｌ以上であり、また、好ましくは３ｍｏｌ／Ｌ以下、より好ましくは２．５ｍｏｌ／Ｌ以下、更に好ましくは２．０ｍｏｌ／Ｌ以下である。 The concentration of these electrolyte salts in the electrolyte is not particularly limited as long as the effects of the present invention are not impaired. The total molar concentration of lithium in the electrolytic solution is preferably 0.3 mol / L or more, and more preferably 0.4 mol / L, in order to set the electric conductivity of the electrolytic solution in a good range and to ensure good battery performance. The amount is more preferably 0.5 mol / L or more, preferably 3 mol / L or less, more preferably 2.5 mol / L or less, and still more preferably 2.0 mol / L or less.
リチウムの総モル濃度が低すぎると、電解液の電気伝導率が不十分の場合があり、一方、濃度が高すぎると、粘度上昇のため電気伝導度が低下する場合があり、電池性能が低下する場合がある。 If the total molar concentration of lithium is too low, the electrical conductivity of the electrolyte may be insufficient. On the other hand, if the concentration is too high, the electrical conductivity may decrease due to the increase in viscosity, and the battery performance may decrease. May.
電気二重層キャパシタ用電解液の電解質塩としては、アンモニウム塩が好ましい。
上記アンモニウム塩としては、以下（ＩＩａ）～（ＩＩｅ）が挙げられる。
（ＩＩａ）テトラアルキル４級アンモニウム塩
一般式（ＩＩａ）： An ammonium salt is preferable as the electrolyte salt of the electrolytic solution for an electric double layer capacitor.
Examples of the ammonium salt include the following (IIa) to (IIe).
(IIa) Tetraalkyl quaternary ammonium salt General formula (IIa):
Figure JPOXMLDOC01-appb-C000056
 （式中、Ｒ１ａ、Ｒ２ａ、Ｒ３ａ及びＲ４ａは同じか又は異なり、いずれも炭素数１～６のエーテル結合を含んでいてもよいアルキル基；Ｘ－はアニオン）
で示されるテトラアルキル４級アンモニウム塩が好ましく例示できる。また、このアンモニウム塩の水素原子の一部又は全部がフッ素原子及び／又は炭素数１～４の含フッ素アルキル基で置換されているものも、耐酸化性が向上する点から好ましい。
Figure JPOXMLDOC01-appb-C000056
 (Wherein, R 1a , R 2a , R 3a and R 4a are the same or different, and each may be an alkyl group containing an ether bond of 1 to 6 carbon atoms; X - is an anion)
Preferred are tetraalkyl quaternary ammonium salts represented by the following. In addition, those in which a part or all of hydrogen atoms of this ammonium salt is substituted with a fluorine atom and / or a fluorine-containing alkyl group having 1 to 4 carbon atoms are also preferable from the viewpoint of improving the oxidation resistance.
具体例としては、一般式（ＩＩａ－１）： As a specific example, general formula (IIa-1):
Figure JPOXMLDOC01-appb-C000057
 （式中、Ｒ１ａ、Ｒ２ａ及びＸ－は前記と同じ；ｘ及びｙは同じか又は異なり０～４の整数で、かつｘ＋ｙ＝４）
で示されるテトラアルキル４級アンモニウム塩、一般式（ＩＩａ－２）：
Figure JPOXMLDOC01-appb-C000057
 (Wherein, R 1a , R 2a and X − are the same as above; x and y are the same or different and are integers of 0 to 4 and x + y = 4)
Tetraalkyl quaternary ammonium salt represented by the general formula (IIa-2):
Figure JPOXMLDOC01-appb-C000058
 （式中、Ｒ５ａは炭素数１～６のアルキル基；Ｒ６ａは炭素数１～６の２価の炭化水素基；Ｒ７ａは炭素数１～４のアルキル基；ｚは１又は２；Ｘ－はアニオン）
で示されるアルキルエーテル基含有トリアルキルアンモニウム塩、
等が挙げられる。アルキルエーテル基を導入することにより、粘性の低下を図ることができる。
Figure JPOXMLDOC01-appb-C000058
 (Wherein, R 5a is an alkyl group having 1 to 6 carbon atoms; R 6a is a divalent hydrocarbon group having 1 to 6 carbon atoms; R 7a is an alkyl group having 1 to 4 carbon atoms; z is 1 or 2; X - is an anion)
Alkyl ether group-containing trialkyl ammonium salt represented by
Etc. The viscosity can be reduced by introducing an alkyl ether group.
アニオンＸ－は、無機アニオンでも有機アニオンでもよい。無機アニオンとしては、例えばＡｌＣｌ４ －、ＢＦ４ －、ＰＦ６ －、ＡｓＦ６ －、ＴａＦ６ －、Ｉ－、ＳｂＦ６ －が挙げられる。有機アニオンとしては、例えばビスオキサラトボレートアニオン、ジフルオロオキサラトボレートアニオン、テトラフルオロオキサラトホスフェートアニオン、ジフルオロビスオキサラトフォスフェートアニオン、ＣＦ３ＣＯＯ－、ＣＦ３ＳＯ３ －、（ＣＦ３ＳＯ２）２Ｎ－、（Ｃ２Ｆ５ＳＯ２）２Ｎ－等が挙げられる。 The anion X − may be an inorganic anion or an organic anion. Examples of the inorganic anion include AlCl 4 − , BF 4 − , PF 6 − , AsF 6 − , TaF 6 − , I − , and SbF 6 − . Examples of the organic anion include bisoxalatoborate anion, difluorooxalatoborate anion, tetrafluorooxalatophosphate anion, difluorobisoxalatophosphate anion, CF 3 COO − , CF 3 SO 3 − , (CF 3 SO 2 ) 2 N − , (C 2 F 5 SO 2 ) 2 N −, and the like.
これらのうち、耐酸化性やイオン解離性が良好な点から、ＢＦ４ －、ＰＦ６ －、ＡｓＦ６ －、ＳｂＦ６ －が好ましい。 Among these, BF 4 − , PF 6 − , AsF 6 − , and SbF 6 − are preferable from the viewpoint of good oxidation resistance and ion dissociation.
テトラアルキル４級アンモニウム塩の好適な具体例としては、Ｅｔ４ＮＢＦ４、Ｅｔ４ＮＣｌＯ４、Ｅｔ４ＮＰＦ６、Ｅｔ４ＮＡｓＦ６、Ｅｔ４ＮＳｂＦ６、Ｅｔ４ＮＣＦ３ＳＯ３、Ｅｔ４Ｎ（ＣＦ３ＳＯ２）２Ｎ、Ｅｔ４ＮＣ４Ｆ９ＳＯ３、Ｅｔ３ＭｅＮＢＦ４、Ｅｔ３ＭｅＮＣｌＯ４、Ｅｔ３ＭｅＮＰＦ６、Ｅｔ３ＭｅＮＡｓＦ６、Ｅｔ３ＭｅＮＳｂＦ６、Ｅｔ３ＭｅＮＣＦ３ＳＯ３、Ｅｔ３ＭｅＮ（ＣＦ３ＳＯ２）２Ｎ、Ｅｔ３ＭｅＮＣ４Ｆ９ＳＯ３を用いればよく、特に、Ｅｔ４ＮＢＦ４、Ｅｔ４ＮＰＦ６、Ｅｔ４ＮＳｂＦ６、Ｅｔ４ＮＡｓＦ６、Ｅｔ３ＭｅＮＢＦ４、Ｎ，Ｎ－ジエチル－Ｎ－メチル－Ｎ－（２－メトキシエチル）アンモニウム塩等が挙げられる。 Preferred specific examples of the tetraalkyl quaternary ammonium salt include Et 4 NBF 4 , Et 4 NClO 4 , Et 4 NPF 6 , Et 4 NAsF 6 , Et 4 NSbF 6 , Et 4 NCF 3 SO 3 , Et 4 N ( CF 3 SO 2 ) 2 N, Et 4 NC 4 F 9 SO 3 , Et 3 MeNBF 4 , Et 3 MeNClO 4 , Et 3 MeNPF 6 , Et 3 MeNAsF 6 , Et 3 MeNSbF 6 , Et 3 MeNCF 3 SO 3 , Et 3 3 MeN (CF 3 SO 2 ) 2 N, Et 3 MeNC 4 F 9 SO 3 may be used, and in particular, Et 4 NBF 4 , Et 4 NPF 6 , Et 4 NSbF 6 , Et 4 NAsF 6 , Et 3 MeNBF 4 , N, N-diethyl-N-methyl-N- (2-methoxyethyl) ammonium salt etc. Be
（ＩＩｂ）スピロ環ビピロリジニウム塩
一般式（ＩＩｂ－１）： (IIb) Spirocyclic Bipyrrolidinium Salt General Formula (IIb-1):
Figure JPOXMLDOC01-appb-C000059
 （式中、Ｒ８ａ及びＲ９ａは同じか又は異なり、いずれも炭素数１～４のアルキル基；Ｘ－はアニオン；ｎ１は０～５の整数；ｎ２は０～５の整数）
で示されるスピロ環ビピロリジニウム塩、一般式（ＩＩｂ－２）：
Figure JPOXMLDOC01-appb-C000059
 (Wherein, R 8a and R 9a are the same or different and each is an alkyl group having 1 to 4 carbon atoms; X - is an anion; n 1 is an integer of 0 to 5; n 2 is an integer of 0 to 5)
A spiro ring bipyrrolidinium salt represented by the general formula (IIb-2):
Figure JPOXMLDOC01-appb-C000060
 （式中、Ｒ１０ａ及びＲ１１ａは同じか又は異なり、いずれも炭素数１～４のアルキル基；Ｘ－はアニオン；ｎ３は０～５の整数；ｎ４は０～５の整数）
で示されるスピロ環ビピロリジニウム塩、又は、一般式（ＩＩｂ－３）：
Figure JPOXMLDOC01-appb-C000060
 (Wherein, R 10a and R 11a are the same or different and each is an alkyl group of 1 to 4 carbon atoms; X - is an anion; n 3 is an integer of 0 to 5; n 4 is an integer of 0 to 5)
Or a spirocyclic bipyrrolidinium salt represented by the general formula (IIb-3):
Figure JPOXMLDOC01-appb-C000061
 （式中、Ｒ１２ａ及びＲ１３ａは同じか又は異なり、いずれも炭素数１～４のアルキル基；Ｘ－はアニオン；ｎ５は０～５の整数；ｎ６は０～５の整数）
で示されるスピロ環ビピロリジニウム塩が好ましく挙げられる。また、このスピロ環ビピロリジニウム塩の水素原子の一部又は全部がフッ素原子及び／又は炭素数１～４の含フッ素アルキル基で置換されているものも、耐酸化性が向上する点から好ましい。
Figure JPOXMLDOC01-appb-C000061
 (Wherein R 12a and R 13a are the same or different and each is an alkyl group having 1 to 4 carbon atoms; X - is an anion; n 5 is an integer of 0 to 5; n 6 is an integer of 0 to 5)
The spiro ring bipyrrolidinium salt shown by these is mentioned preferably. Further, those in which part or all of the hydrogen atoms of this spirocyclic bipyrrolidinium salt are substituted with a fluorine atom and / or a fluorine-containing alkyl group having 1 to 4 carbon atoms are also preferable from the viewpoint of improving the oxidation resistance.
アニオンＸ－の好ましい具体例は、（ＩＩａ）の場合と同じである。なかでも、解離性が高く、高電圧下での内部抵抗が低い点から、ＢＦ４－、ＰＦ６－、（ＣＦ３ＳＯ２）２Ｎ－又は（Ｃ２Ｆ５ＳＯ２）２Ｎ－が好ましい。 Anion X - of the preferred embodiment are the same as for (IIa). Among them, high dissociative, terms the internal resistance is low under a high voltage, BF 4 -, PF 6 - , (CF 3 SO 2) 2 N- or (C 2 F 5 SO 2) 2 N- is preferable.
スピロ環ビピロリジニウム塩の好ましい具体例としては、例えば、
Figure JPOXMLDOC01-appb-C000062
 等が挙げられる。 Preferred specific examples of the spirocyclic bipyrrolidinium salt include, for example,
Figure JPOXMLDOC01-appb-C000062
 Etc.
このスピロ環ビピロリジニウム塩は溶媒への溶解性、耐酸化性、イオン伝導性の点で優れている。 The spirocyclic bipyrrolidinium salt is excellent in solubility in solvents, oxidation resistance, and ion conductivity.
（ＩＩｃ）イミダゾリウム塩
一般式（ＩＩｃ）： (IIc) imidazolium salt general formula (IIc):
Figure JPOXMLDOC01-appb-C000063
 （式中、Ｒ１４ａ及びＲ１５ａは同じか又は異なり、いずれも炭素数１～６のアルキル基；Ｘ－はアニオン）
で示されるイミダゾリウム塩が好ましく例示できる。また、このイミダゾリウム塩の水素原子の一部又は全部がフッ素原子及び／又は炭素数１～４の含フッ素アルキル基で置換されているものも、耐酸化性が向上する点から好ましい。
Figure JPOXMLDOC01-appb-C000063
 (Wherein, R 14a and R 15a are the same or different, and each is an alkyl group having 1 to 6 carbon atoms; X - is an anion)
The imidazolium salt shown by these can be illustrated preferably. Further, those in which part or all of hydrogen atoms of this imidazolium salt is substituted with a fluorine atom and / or a fluorine-containing alkyl group having 1 to 4 carbon atoms are also preferable from the viewpoint of improving the oxidation resistance.
アニオンＸ－の好ましい具体例は、（ＩＩａ）と同じである。 Anion X - of the preferred embodiment is the same as (IIa).
好ましい具体例としては、例えば As a preferred embodiment, for example,
Figure JPOXMLDOC01-appb-C000064
 等が挙げられる。
Figure JPOXMLDOC01-appb-C000064
 Etc.
このイミダゾリウム塩は粘性が低く、また溶解性が良好な点で優れている。 This imidazolium salt is excellent in that it has low viscosity and good solubility.
（ＩＩｄ）：Ｎ－アルキルピリジニウム塩
一般式（ＩＩｄ）： (IId): N-alkylpyridinium salt general formula (IId):
Figure JPOXMLDOC01-appb-C000065
 （式中、Ｒ１６ａは炭素数１～６のアルキル基；Ｘ－はアニオン）
で示されるＮ－アルキルピリジニウム塩が好ましく例示できる。また、このＮ－アルキルピリジニウム塩の水素原子の一部又は全部がフッ素原子及び／又は炭素数１～４の含フッ素アルキル基で置換されているものも、耐酸化性が向上する点から好ましい。
Figure JPOXMLDOC01-appb-C000065
 (Wherein, R 16a is an alkyl group having 1 to 6 carbon atoms; X - is an anion)
The N-alkyl pyridinium salt represented by can be preferably exemplified. Further, it is also preferable from the viewpoint that the oxidation resistance is improved, in which part or all of hydrogen atoms of this N-alkylpyridinium salt is substituted by a fluorine atom and / or a fluorine-containing alkyl group having 1 to 4 carbon atoms.
アニオンＸ－の好ましい具体例は、（ＩＩａ）と同じである。 Anion X - of the preferred embodiment is the same as (IIa).
好ましい具体例としては、例えば As a preferred embodiment, for example,
Figure JPOXMLDOC01-appb-C000066
 等が挙げられる。
Figure JPOXMLDOC01-appb-C000066
 Etc.
このＮ－アルキルピリジニウム塩は粘性が低く、また溶解性が良好な点で優れている。 This N-alkylpyridinium salt is excellent in that it has low viscosity and good solubility.
（ＩＩｅ）Ｎ，Ｎ－ジアルキルピロリジニウム塩
一般式（ＩＩｅ）： (IIe) N, N-dialkylpyrrolidinium salts of general formula (IIe):
Figure JPOXMLDOC01-appb-C000067
 （式中、Ｒ１７ａ及びＲ１８ａは同じか又は異なり、いずれも炭素数１～６のアルキル基；Ｘ－はアニオン）
で示されるＮ，Ｎ－ジアルキルピロリジニウム塩が好ましく例示できる。また、このＮ，Ｎ－ジアルキルピロリジニウム塩の水素原子の一部又は全部がフッ素原子及び／又は炭素数１～４の含フッ素アルキル基で置換されているものも、耐酸化性が向上する点から好ましい。
Figure JPOXMLDOC01-appb-C000067
 (Wherein, R 17a and R 18a are the same or different and each is an alkyl group having 1 to 6 carbon atoms; X - is an anion)
The N, N-dialkyl pyrrolidinium salt represented by can be preferably exemplified. In addition, oxidation resistance is also improved in the case where part or all of the hydrogen atoms of this N, N-dialkylpyrrolidinium salt is substituted with a fluorine atom and / or a fluorine-containing alkyl group having 1 to 4 carbon atoms. It is preferable from the point of view.
アニオンＸ－の好ましい具体例は、（ＩＩａ）と同じである。 Anion X - of the preferred embodiment is the same as (IIa).
好ましい具体例としては、例えば As a preferred embodiment, for example,
Figure JPOXMLDOC01-appb-C000068
Figure JPOXMLDOC01-appb-C000068
Figure JPOXMLDOC01-appb-C000069
 等が挙げられる。
Figure JPOXMLDOC01-appb-C000069
 Etc.
このＮ，Ｎ－ジアルキルピロリジニウム塩は粘性が低く、また溶解性が良好な点で優れている。 This N, N-dialkylpyrrolidinium salt is excellent in that it has low viscosity and good solubility.
これらのアンモニウム塩のうち、（ＩＩａ）、（ＩＩｂ）及び（ＩＩｃ）が溶解性、耐酸化性、イオン伝導性が良好な点で好ましく、更には Among these ammonium salts, (IIa), (IIb) and (IIc) are preferable in terms of good solubility, oxidation resistance and ion conductivity, and further preferred
Figure JPOXMLDOC01-appb-C000070
 （式中、Ｍｅはメチル基；Ｅｔはエチル基；Ｘ－、ｘ、ｙは式（ＩＩａ－１）と同じ）
が好ましい。
Figure JPOXMLDOC01-appb-C000070
 (Wherein, Me is a methyl group; Et is an ethyl group; X − , x and y are the same as in formula (IIa-1))
Is preferred.
また、電気二重層キャパシタ用電解質塩として、リチウム塩を用いてもよい。リチウム塩としては、例えば、ＬｉＰＦ６、ＬｉＢＦ４、ＬｉＮ（ＦＳＯ２）２、ＬｉＡｓＦ６、ＬｉＳｂＦ６、ＬｉＮ（ＳＯ２Ｃ２Ｈ５）２が好ましい。
更に容量を向上させるために、マグネシウム塩を用いてもよい。マグネシウム塩としては、例えば、Ｍｇ（ＣｌＯ４）２、Ｍｇ（ＯＯＣ２Ｈ５）２等が好ましい。 In addition, a lithium salt may be used as an electrolyte salt for an electric double layer capacitor. Examples of the lithium salt, LiPF 6, LiBF 4, LiN (FSO 2) 2, LiAsF 6, LiSbF 6, LiN (SO 2 C 2 H 5) 2 is preferred.
Magnesium salts may be used to further improve the capacity. The magnesium salt, e.g., Mg (ClO 4) 2, Mg (OOC 2 H 5) 2 and the like are preferable.
電解質塩が上記アンモニウム塩である場合、濃度は、０．７モル／リットル以上であることが好ましい。０．７モル／リットル未満であると、低温特性が悪くなるだけでなく、初期内部抵抗が高くなってしまうおそれがある。上記電解質塩の濃度は、０．９モル／リットル以上であることがより好ましい。
上記濃度の上限は、低温特性の点で、２．０モル／リットル以下であることが好ましく、１．５モル／リットル以下であることがより好ましい。
上記アンモニウム塩が、４フッ化ホウ酸トリエチルメチルアンモニウム（ＴＥＭＡＢＦ４）の場合、その濃度は、低温特性に優れる点で、０．７～１．５モル／リットルであることが好ましい。
また、４フッ化ホウ酸スピロビピロリジニウム（ＳＢＰＢＦ４）の場合は、０．７～２．０モル／リットルであることが好ましい。 When the electrolyte salt is the above ammonium salt, the concentration is preferably 0.7 mol / l or more. If the amount is less than 0.7 mol / liter, not only the low temperature characteristics may be deteriorated, but also the initial internal resistance may be increased. The concentration of the electrolyte salt is more preferably 0.9 mol / l or more.
The upper limit of the concentration is preferably 2.0 mol / l or less, more preferably 1.5 mol / l or less, in terms of low temperature characteristics.
When the above ammonium salt is triethylmethyl tetrafluoroborate (TEMABF 4 ), the concentration is preferably 0.7 to 1.5 mol / l in terms of excellent low temperature characteristics.
In the case of spirobipyrrolidinium tetrafluoride (SBPBF 4 ), it is preferably 0.7 to 2.0 mol / liter.
本発明の電解液は、一般式（２）：
Figure JPOXMLDOC01-appb-C000071
 （式中、Ｘ２１は少なくともＨ又はＣを含む基、ｎ２１は１～３の整数、Ｙ２１及びＺ２１は、同じか又は異なり、少なくともＨ、Ｃ、Ｏ又はＦを含む基、ｎ２２は０又は１、Ｙ２１及びＺ２１はお互いに結合して環を形成してもよい。）で示される化合物（２）を更に含むことが好ましい。上記電解液が化合物（２）を含むと、高温で保管した場合でも、容量保持率が一層低下しにくく、ガスの発生量が更に増加しにくい。 The electrolytic solution of the present invention has the general formula (2):
Figure JPOXMLDOC01-appb-C000071
 (Wherein, X 21 is a group containing at least H or C, n 21 is an integer of 1 to 3, Y 21 and Z 21 are the same or different, a group containing at least H, C, O or F, n 22 Preferably further includes a compound (2) shown by 0), 1 and Y 21 and Z 21 may be bonded to each other to form a ring). When the electrolytic solution contains the compound (2), the capacity retention ratio is less likely to be further reduced even when stored at high temperature, and the amount of gas generation is less likely to be further increased.
ｎ２１が２又は３の場合、２つ又は３つのＸ２１は同じであっても異なっていてもよい。
Ｙ２１及びＺ２１が複数存在する場合、複数存在するＹ２１及びＺ２１は同じであっても異なっていてもよい。 When n 21 is 2 or 3, two or three X 21 s may be the same or different.
When a plurality of Y 21 and Z 21 are present, the plurality of Y 21 and Z 21 may be the same or different.
Ｘ２１としては、－ＣＹ２１Ｚ２１－（式中、Ｙ２１及びＺ２１は上記のとおり）又は－ＣＹ２１＝ＣＺ２１－（式中、Ｙ２１及びＺ２１は上記のとおり）で示される基が好ましい。 As X 21, it is represented by —CY 21 Z 21 — (wherein Y 21 and Z 21 are as described above) or —CY 21 = CZ 21 − (wherein Y 21 and Z 21 as described above) Groups are preferred.
Ｙ２１としては、Ｈ－、Ｆ－、ＣＨ３－、ＣＨ３ＣＨ２－、ＣＨ３ＣＨ２ＣＨ２－、ＣＦ３－、ＣＦ３ＣＦ２－、ＣＨ２ＦＣＨ２－及びＣＦ３ＣＦ２ＣＦ２－からなる群より選択される少なくとも１種が好ましい。
Ｚ２１としては、Ｈ－、Ｆ－、ＣＨ３－、ＣＨ３ＣＨ２－、ＣＨ３ＣＨ２ＣＨ２－、ＣＦ３－、ＣＦ３ＣＦ２－、ＣＨ２ＦＣＨ２－及びＣＦ３ＣＦ２ＣＦ２－からなる群より選択される少なくとも１種が好ましい。 As Y 21 , H-, F-, CH 3- , CH 3 CH 2- , CH 3 CH 2 CH 2- , CF 3- , CF 3 CF 2- , CH 2 FCH 2 -and CF 3 CF 2 CF At least one selected from the group consisting of 2- is preferred.
As Z 21 , H-, F-, CH 3- , CH 3 CH 2- , CH 3 CH 2 CH 2- , CF 3- , CF 3 CF 2- , CH 2 FCH 2 -and CF 3 CF 2 CF At least one selected from the group consisting of 2- is preferred.
又は、Ｙ２１及びＺ２１は、お互いに結合して、不飽和結合を含んでもよく、芳香族性を有していてもよい炭素環又は複素環を形成することができる。環の炭素数は３～２０が好ましい。 Alternatively, Y 21 and Z 21 may be bonded to each other to form a carbocyclic or heterocyclic ring which may contain an unsaturated bond and which may have aromaticity. The number of carbon atoms in the ring is preferably 3 to 20.
次いで、化合物（２）の具体例について説明する。なお、以下の例示において「類縁体」とは、例示される酸無水物の構造の一部を、本発明の趣旨に反しない範囲で、別の構造に置き換えることにより得られる酸無水物を指すもので、例えば複数の酸無水物からなる二量体、三量体及び四量体等、又は、置換基の炭素数が同じではあるが分岐鎖を有する等構造異性のもの、置換基が酸無水物に結合する部位が異なるもの等が挙げられる。 Next, specific examples of the compound (2) will be described. In the following examples, “analog” refers to an acid anhydride obtained by replacing a part of the structure of the exemplified acid anhydride with another structure without departing from the spirit of the present invention. For example, dimers, trimers and tetramers of multiple acid anhydrides, etc., or equistructural isomers having the same carbon number of substituents but having branched chains, and the substituent is an acid Those having different sites of binding to an anhydride and the like can be mentioned.
５員環構造を形成している酸無水物の具体例としては、無水コハク酸、メチルコハク酸無水物（４－メチルコハク酸無水物）、ジメチルコハク酸無水物（４，４－ジメチルコハク酸無水物、４，５－ジメチルコハク酸無水物等）、４，４，５－トリメチルコハク酸無水物、４，４，５，５－テトラメチルコハク酸無水物、４－ビニルコハク酸無水物、４，５－ジビニルコハク酸無水物、フェニルコハク酸無水物（４－フェニルコハク酸無水物）、４，５－ジフェニルコハク酸無水物、４，４－ジフェニルコハク酸無水物、無水シトラコン酸、無水マレイン酸、メチルマレイン酸無水物（４－メチルマレイン酸無水物）、４，５－ジメチルマレイン酸無水物、フェニルマレイン酸無水物（４－フェニルマレイン酸無水物）、４，５－ジフェニルマレイン酸無水物、イタコン酸無水物、５－メチルイタコン酸無水物、５，５－ジメチルイタコン酸無水物、無水フタル酸、３，４，５，６－テトラヒドロフタル酸無水物等、及びそれらの類縁体等が挙げられる。 Specific examples of the acid anhydride having a five-membered ring structure include succinic anhydride, methyl succinic anhydride (4-methyl succinic anhydride), and dimethyl succinic anhydride (4, 4-dimethyl succinic anhydride) , 4,5-dimethylsuccinic anhydride etc.), 4,4,5-trimethylsuccinic anhydride, 4,4,5,5-tetramethylsuccinic anhydride, 4-vinylsuccinic anhydride, 4,5 -Divinylsuccinic anhydride, phenylsuccinic anhydride (4-phenylsuccinic anhydride), 4,5-diphenylsuccinic anhydride, 4,4-diphenylsuccinic anhydride, citraconic anhydride, maleic anhydride, Methylmaleic anhydride (4-methylmaleic anhydride), 4,5-dimethylmaleic anhydride, phenylmaleic anhydride (4-phenylmaleic anhydride), 4,5-diphenyl Leic anhydride, itaconic anhydride, 5-methyl itaconic anhydride, 5,5-dimethyl itaconic anhydride, phthalic anhydride, 3,4,5,6-tetrahydrophthalic anhydride etc., and the like Analogs and the like can be mentioned.
６員環構造を形成している酸無水物の具体例としては、シクロヘキサンジカルボン酸無水物（シクロヘキサン－１，２－ジカルボン酸無水物等）、４－シクロヘキセン－１，２－ジカルボン酸無水物、無水グルタル酸、無水グルタコン酸、２－フェニルグルタル酸無水物等、及びそれらの類縁体等が挙げられる。 Specific examples of the acid anhydride having a 6-membered ring structure include cyclohexanedicarboxylic acid anhydride (cyclohexane-1,2-dicarboxylic acid anhydride etc.), 4-cyclohexene-1,2-dicarboxylic acid anhydride, Examples thereof include glutaric anhydride, glutaconic anhydride, 2-phenylglutaric anhydride and the like, and analogs thereof.
その他の環状構造を形成している酸無水物の具体例としては、５－ノルボルネン－２，３－ジカルボン酸無水物、シクロペンタンテトラカルボン酸二無水物、ピロメリット酸無水物、無水ジグリコール酸等、及びそれらの類縁体等が挙げられる。 As specific examples of the acid anhydride forming the cyclic structure, 5-norbornene-2,3-dicarboxylic acid anhydride, cyclopentanetetracarboxylic acid dianhydride, pyromellitic acid anhydride, diglycolic acid anhydride And their analogues.
環状構造を形成するとともに、ハロゲン原子で置換された酸無水物の具体例としては、モノフルオロコハク酸無水物（４－フルオロコハク酸無水物等）、４，４－ジフルオロコハク酸無水物、４，５－ジフルオロコハク酸無水物、４，４，５－トリフルオロコハク酸無水物、トリフルオロメチルコハク酸無水物、テトラフルオロコハク酸無水物（４，４，５，５－テトラフルオロコハク酸無水物）、４－フルオロマレイン酸無水物、４，５－ジフルオロマレイン酸無水物、トリフルオロメチルマレイン酸無水物、５－フルオロイタコン酸無水物、５，５－ジフルオロイタコン酸無水物等、及びそれらの類縁体等が挙げられる。 Specific examples of the acid anhydride which forms a cyclic structure and is substituted by a halogen atom include monofluorosuccinic anhydride (4-fluorosuccinic anhydride and the like), 4,4-difluorosuccinic anhydride, , 5-Difluorosuccinic anhydride, 4,4,5-trifluorosuccinic anhydride, trifluoromethylsuccinic anhydride, tetrafluorosuccinic anhydride (4,4,5,5-tetrafluorosuccinic anhydride ), 4-fluoromaleic anhydride, 4,5-difluoromaleic anhydride, trifluoromethylmaleic anhydride, 5-fluoroitaconic anhydride, 5,5-difluoroitaconic anhydride, etc. And the like.
化合物（２）としては、なかでも、無水グルタル酸、無水シトラコン酸、無水グルタコン酸、無水イタコン酸、無水ジグリコール酸、シクロヘキサンジカルボン酸無水物、シクロペンタンテトラカルボン酸二無水物、４－シクロヘキセン－１，２－ジカルボン酸無水物、３，４，５，６－テトラヒドロフタル酸無水物、５－ノルボルネン－２，３－ジカルボン酸無水物、フェニルコハク酸無水物、２－フェニルグルタル酸無水物、無水マレイン酸、メチルマレイン酸無水物、トリフルオロメチルマレイン酸無水物、フェニルマレイン酸無水物、無水コハク酸、メチルコハク酸無水物、ジメチルコハク酸無水物、トリフルオロメチルコハク酸無水物、モノフルオロコハク酸無水物、テトラフルオロコハク酸無水物等が好ましく、無水マレイン酸、メチルマレイン酸無水物、トリフルオロメチルマレイン酸無水物、無水コハク酸、メチルコハク酸無水物、トリフルオロメチルコハク酸無水物、テトラフルオロコハク酸無水物がより好ましく、無水マレイン酸、無水コハク酸が更に好ましい。 As the compound (2), among them, glutaric anhydride, citraconic anhydride, glutaconic anhydride, itaconic anhydride, diglycolic anhydride, cyclohexanedicarboxylic acid anhydride, cyclopentanetetracarboxylic acid dianhydride, 4-cyclohexene- 1,2-dicarboxylic acid anhydride, 3,4,5,6-tetrahydrophthalic acid anhydride, 5-norbornene-2,3-dicarboxylic acid anhydride, phenyl succinic acid anhydride, 2-phenyl glutaric acid anhydride, Maleic anhydride, methylmaleic anhydride, trifluoromethylmaleic anhydride, phenylmaleic anhydride, succinic anhydride, methylsuccinic anhydride, dimethylsuccinic anhydride, trifluoromethylsuccinic anhydride, monofluorosuccinic anhydride Acid anhydride, tetrafluorosuccinic anhydride and the like are preferable, and maleic anhydride Methylmaleic anhydride, trifluoromethylmaleic anhydride, succinic anhydride, methylsuccinic anhydride, trifluoromethylsuccinic anhydride, tetrafluorosuccinic anhydride are more preferable, and maleic anhydride and succinic anhydride are more preferable. preferable.
化合物（２）は、一般式（３）： The compound (2) is represented by the general formula (3):
Figure JPOXMLDOC01-appb-C000072
 （式中、Ｘ３１～Ｘ３４は、同じか又は異なり、少なくともＨ、Ｃ、Ｏ又はＦを含む基）で示される化合物（３）、及び、一般式（４）：
Figure JPOXMLDOC01-appb-C000072
 (Wherein, X 31 to X 34 are the same or different and each is a group containing at least H, C, O or F), a compound (3), and a compound represented by the general formula (4):
Figure JPOXMLDOC01-appb-C000073
 （式中、Ｘ４１及びＸ４２は、同じか又は異なり、少なくともＨ、Ｃ、Ｏ又はＦを含む基）で示される化合物（４）からなる群より選択される少なくとも１種であることが好ましい。
Figure JPOXMLDOC01-appb-C000073
 (Wherein, X 41 and X 42 are the same or different and is preferably at least one selected from the group consisting of compounds (4) represented by a group containing at least H, C, O or F) .
Ｘ３１～Ｘ３４としては、同じか又は異なり、アルキル基、フッ素化アルキル基、アルケニル基及びフッ素化アルケニル基からなる群より選択される少なくとも１種が好ましい。Ｘ３１～Ｘ３４の炭素数は、１～１０が好ましく、１～３がより好ましい。 As X 31 to X 34 , at least one selected from the group consisting of an alkyl group, a fluorinated alkyl group, an alkenyl group and a fluorinated alkenyl group, which may be the same or different, is preferable. The carbon number of X 31 to X 34 is preferably 1 to 10, and more preferably 1 to 3.
Ｘ３１～Ｘ３４としては、同じか又は異なり、Ｈ－、Ｆ－、ＣＨ３－、ＣＨ３ＣＨ２－、ＣＨ３ＣＨ２ＣＨ２－、ＣＦ３－、ＣＦ３ＣＦ２－、ＣＨ２ＦＣＨ２－及びＣＦ３ＣＦ２ＣＦ２－からなる群より選択される少なくとも１種がより好ましい。 As X 31 to X 34 , the same or different, H-, F-, CH 3- , CH 3 CH 2- , CH 3 CH 2 CH 2- , CF 3- , CF 3 CF 2- , CH 2 FCH 2 - and CF 3 CF 2 CF 2 - at least one member selected from the group consisting of is more preferable.
Ｘ４１及びＸ４２としては、同じか又は異なり、アルキル基、フッ素化アルキル基、アルケニル基及びフッ素化アルケニル基からなる群より選択される少なくとも１種が好ましい。Ｘ４１及びＸ４２の炭素数は、１～１０が好ましく、１～３がより好ましい。 As X 41 and X 42 , at least one selected from the group consisting of an alkyl group, a fluorinated alkyl group, an alkenyl group and a fluorinated alkenyl group, which may be the same or different, is preferable. The number of carbon atoms of X 41 and X 42 is preferably 1 to 10, 1 to 3 more preferred.
Ｘ４１及びＸ４２としては、同じか又は異なり、Ｈ－、Ｆ－、ＣＨ３－、ＣＨ３ＣＨ２－、ＣＨ３ＣＨ２ＣＨ２－、ＣＦ３－、ＣＦ３ＣＦ２－、ＣＨ２ＦＣＨ２－及びＣＦ３ＣＦ２ＣＦ２－からなる群より選択される少なくとも１種がより好ましい。 As X 41 and X 42 , the same or different, H-, F-, CH 3- , CH 3 CH 2- , CH 3 CH 2 CH 2- , CF 3- , CF 3 CF 2- , CH 2 FCH 2 - and CF 3 CF 2 CF 2 - at least one member selected from the group consisting of is more preferable.
化合物（３）は、以下の化合物のいずれかであることが好ましい。 The compound (3) is preferably any of the following compounds.
Figure JPOXMLDOC01-appb-C000074
Figure JPOXMLDOC01-appb-C000074
化合物（４）は、以下の化合物のいずれかであることが好ましい。 The compound (4) is preferably any of the following compounds.
Figure JPOXMLDOC01-appb-C000075
Figure JPOXMLDOC01-appb-C000075
上記電解液は、高温で保管した場合でも、容量保持率が一層低下しにくく、ガスの発生量が更に増加しにくいことから、上記電解液に対して、０．０００１～１５質量％の化合物（２）を含むことが好ましい。化合物（２）の含有量としては、０．０１～１０質量％がより好ましく、０．１～３質量％が更に好ましく、０．１～１．０質量％が特に好ましい。 Even when the electrolyte is stored at high temperature, the capacity retention is less likely to decrease and the amount of gas generation is further difficult to increase. Therefore, 0.0001 to 15% by mass of the compound (based on the electrolyte) It is preferable to include 2). The content of the compound (2) is more preferably 0.01 to 10% by mass, still more preferably 0.1 to 3% by mass, and particularly preferably 0.1 to 1.0% by mass.
上記電解液が化合物（３）及び（４）の両方を含む場合、高温で保管した場合でも、容量保持率が一層低下しにくく、ガスの発生量が更に増加しにくいことから、上記電解液は、上記電解液に対して、０．０８～２．５０質量％の化合物（３）及び０．０２～１．５０質量％の化合物（４）を含むことが好ましく、０．８０～２．５０質量％の化合物（３）及び０．０８～１．５０質量％の化合物（４）を含むことがより好ましい。 When the electrolytic solution contains both the compounds (3) and (4), the capacity retention is less likely to decrease even when stored at high temperatures, and the amount of gas generation is further difficult to increase. And 0.08 to 2.50% by mass of the compound (3) and 0.02 to 1.50% by mass of the compound (4) based on the electrolytic solution, preferably 0.80 to 2.50. More preferably, the composition contains 3% by mass of the compound (3) and 0.08 to 1.50% by mass of the compound (4).
本発明の電解液は、下記一般式（１ａ）、（１ｂ）及び（１ｃ）で表されるニトリル化合物からなる群より選択される少なくとも１種を含んでもよい。
Figure JPOXMLDOC01-appb-C000076
 （式中、Ｒａ及びＲｂは、それぞれ独立して、水素原子、シアノ基（ＣＮ）、ハロゲン原子、アルキル基、又は、アルキル基の少なくとも一部の水素原子をハロゲン原子で置換した基を表す。ｎは１～１０の整数を表す。）
Figure JPOXMLDOC01-appb-C000077
 （式中、Ｒｃは、水素原子、ハロゲン原子、アルキル基、アルキル基の少なくとも一部の水素原子をハロゲン原子で置換した基、又は、ＮＣ－Ｒｃ１－Ｘｃ１－（Ｒｃ１はアルキレン基、Ｘｃ１は酸素原子又は硫黄原子を表す。）で表される基を表す。Ｒｄ及びＲｅは、それぞれ独立して、水素原子、ハロゲン原子、アルキル基、又は、アルキル基の少なくとも一部の水素原子をハロゲン原子で置換した基を表す。ｍは１～１０の整数を表す。）
Figure JPOXMLDOC01-appb-C000078
 （式中、Ｒｆ、Ｒｇ、Ｒｈ及びＲｉは、それぞれ独立して、シアノ基（ＣＮ）を含む基、水素原子（Ｈ）、ハロゲン原子、アルキル基、又は、アルキル基の少なくとも一部の水素原子をハロゲン原子で置換した基を表す。ただし、Ｒｆ、Ｒｇ、Ｒｈ及びＲｉのうち少なくとも１つはシアノ基を含む基である。ｌは１～３の整数を表す。）
これにより、電気化学デバイスの高温保存特性を向上させることができる。上記ニトリル化合物を単独で用いてもよく、２種以上を任意の組み合わせ及び比率で併用してもよい。 The electrolytic solution of the present invention may contain at least one selected from the group consisting of nitrile compounds represented by the following general formulas (1a), (1b) and (1c).
Figure JPOXMLDOC01-appb-C000076
 (Wherein, R a and R b each independently represent a hydrogen atom, a cyano group (CN), a halogen atom, an alkyl group, or a group obtained by substituting at least a part of hydrogen atoms of an alkyl group with a halogen atom N represents an integer of 1 to 10)
Figure JPOXMLDOC01-appb-C000077
 (Wherein, R c is a hydrogen atom, a halogen atom, an alkyl group, a group obtained by substituting at least a part of hydrogen atoms of the alkyl group with a halogen atom, or NC-R c1 -X c1- (R c is an alkylene group And X c1 represents an oxygen atom or a sulfur atom) R d and R e each independently represent at least a part of a hydrogen atom, a halogen atom, an alkyl group or an alkyl group Represents a group in which a hydrogen atom of is substituted by a halogen atom, m represents an integer of 1 to 10)
Figure JPOXMLDOC01-appb-C000078
 (Wherein, R f , R g , R h and R i are each independently at least one of a group containing a cyano group (CN), a hydrogen atom (H), a halogen atom, an alkyl group, or an alkyl group And at least one of R f , R g , R h and R i is a group containing a cyano group, and l represents an integer of 1 to 3. .)
This can improve the high temperature storage characteristics of the electrochemical device. The above nitrile compounds may be used alone, or two or more thereof may be used in any combination and ratio.
上記一般式（１ａ）において、Ｒａ及びＲｂは、それぞれ独立して、水素原子、シアノ基（ＣＮ）、ハロゲン原子、アルキル基、又は、アルキル基の少なくとも一部の水素原子をハロゲン原子で置換した基である。
ハロゲン原子としては、例えば、フッ素原子、塩素原子、臭素原子、ヨウ素原子が挙げられる。中でもフッ素原子が好ましい。
アルキル基としては、炭素数１～５のものが好ましい。アルキル基の具体例としては、メチル基、エチル基、プロピル基、イソプロピル基、ブチル基、イソブチル基、ｔｅｒｔ－ブチル基等が挙げられる。
アルキル基の少なくとも一部の水素原子をハロゲン原子で置換した基としては、上述したアルキル基の少なくとも一部の水素原子を上述したハロゲン原子で置換した基が挙げられる。
Ｒａ及びＲｂがアルキル基、又は、アルキル基の少なくとも一部の水素原子をハロゲン原子で置換した基である場合は、ＲａとＲｂとが互いに結合して環構造（例えば、シクロヘキサン環）を形成していてもよい。
Ｒａ及びＲｂは、水素原子又はアルキル基であることが好ましい。 In the above general formula (1a), R a and R b each independently represent a hydrogen atom, a cyano group (CN), a halogen atom, an alkyl group, or a hydrogen atom of at least part of the alkyl group as a halogen atom It is a substituted group.
As a halogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom is mentioned, for example. Among them, a fluorine atom is preferable.
The alkyl group is preferably one having 1 to 5 carbon atoms. Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group and a tert-butyl group.
As a group which substituted at least one hydrogen atom of the alkyl group by the halogen atom, a group which substituted at least one hydrogen atom of the above-mentioned alkyl group by the above-mentioned halogen atom can be mentioned.
When R a and R b are an alkyl group or a group obtained by substituting at least a part of hydrogen atoms of an alkyl group with a halogen atom, R a and R b are bonded to each other to form a ring structure (eg cyclohexane ring ) May be formed.
R a and R b are preferably a hydrogen atom or an alkyl group.
上記一般式（１ａ）において、ｎは１～１０の整数である。ｎが２以上である場合、ｎ個のＲａは全て同じであってもよく、少なくとも一部が異なっていてもよい。Ｒｂについても同様である。ｎは、１～７の整数が好ましく、２～５の整数がより好ましい。 In the above general formula (1a), n is an integer of 1 to 10. When n is 2 or more, n pieces of R a may be the same for all, it may be at least partially different. The same applies to R b . n is preferably an integer of 1 to 7, and more preferably an integer of 2 to 5.
上記一般式（１ａ）で表されるニトリル化合物としては、ジニトリル及びトリカルボニトリルが好ましい。
ジニトリルの具体例としては、マロノニトリル、スクシノニトリル、グルタロニトリル、アジポニトリル、ピメロニトリル、スベロニトリル、アゼラニトリル、セバコニトリル、ウンデカンジニトリル、ドデカンジニトリル、メチルマロノニトリル、エチルマロノニトリル、イソプロピルマロノニトリル、ｔｅｒｔ－ブチルマロノニトリル、メチルスクシノニトリル、２，２－ジメチルスクシノニトリル、２，３－ジメチルスクシノニトリル、２，３，３－トリメチルスクシノニトリル、２，２，３，３－テトラメチルスクシノニトリル、２，３－ジエチル－２，３－ジメチルスクシノニトリル、２，２－ジエチル－３，３－ジメチルスクシノニトリル、ビシクロヘキシル－１，１－ジカルボニトリル、ビシクロヘキシル－２，２－ジカルボニトリル、ビシクロヘキシル－３，３－ジカルボニトリル、２，５－ジメチル－２，５－ヘキサンジカルボニトリル、２，３－ジイソブチル－２，３－ジメチルスクシノニトリル、２，２－ジイソブチル－３，３－ジメチルスクシノニトリル、２－メチルグルタロニトリル、２，３－ジメチルグルタロニトリル、２，４－ジメチルグルタロニトリル、２，２，３，３－テトラメチルグルタロニトリル、２，２，４，４－テトラメチルグルタロニトリル、２，２，３，４－テトラメチルグルタロニトリル、２，３，３，４－テトラメチルグルタロニトリル、１，４－ジシアノペンタン、２，６－ジシアノヘプタン、２，７－ジシアノオクタン、２，８－ジシアノノナン、１，６－ジシアノデカン、１，２－ジジアノベンゼン、１，３－ジシアノベンゼン、１，４－ジシアノベンゼン、３，３’－（エチレンジオキシ）ジプロピオニトリル、３，３’－（エチレンジチオ）ジプロピオニトリル、３，９－ビス（２－シアノエチル）－２，４，８，１０－テトラオキサスピロ［５，５］ウンデカン、ブタンニトリル、フタロニトリル等を例示できる。これらのうち、特に好ましいのはスクシノニトリル、グルタロニトリル、アジポニトリルである。
また、トリカルボニトリルの具体例としては、ペンタントリカルボニトリル、プロパントリカルボニトリル、１，３，５－ヘキサントリカルボニトリル、１，３，６－ヘキサントリカルボニトリル、ヘプタントリカルボニトリル、１，２，３－プロパントリカルボニトリル、１，３，５－ペンタントリカルボニトリル、シクロヘキサントリカルボニトリル、トリスシアノエチルアミン、トリスシアノエトキシプロパン、トリシアノエチレン、トリス（２－シアノエチル）アミン等が挙げられ特に好ましいものは、１，３，６－ヘキサントリカルボニトリル、シクロヘキサントリカルボニトリルであり、最も好ましいものはシクロヘキサントリカルボニトリルである。 As a nitrile compound represented by the said General formula (1a), dinitrile and tricarbonitrile are preferable.
Specific examples of the dinitrile include malononitrile, succinonitrile, glutaronitrile, adiponitrile, pimeronitrile, suberonitrile, azera nitrile, sebaconitrile, undecane dinitrile, dodecane dinitrile, methyl malononitrile, ethyl malononitrile, isopropyl malononitrile, tert-butyl Malononitrile, methyl succinonitrile, 2, 2-dimethyl succinonitrile, 2,3- dimethyl succinonitrile, 2, 3, 3- trimethyl succinonitrile, 2, 2, 3, 3- tetramethyl succinonitrile 2,3-Diethyl-2,3-dimethylsuccinonitrile, 2,2-diethyl-3,3-dimethylsuccinonitrile, bicyclohexyl-1,1-dicarbonitrile, bicyclohexyl-2,2-dicarb Tolyl, bicyclohexyl-3,3-dicarbonitrile, 2,5-dimethyl-2,5-hexanedicarbonitrile, 2,3-diisobutyl-2,3-dimethylsuccinonitrile, 2,2-diisobutyl-3 , 3-dimethylsuccinonitrile, 2-methylglutaronitrile, 2,3-dimethylglutaronitrile, 2,4-dimethylglutaronitrile, 2,2,3,3-tetramethylglutaronitrile, 2,2 1,4,4-Tetramethylglutaronitrile, 2,2,3,4-Tetramethylglutaronitrile, 2,3,3,4-Tetramethylglutaronitrile, 1,4-dicyanopentane, 2,6- Dicyanoheptane, 2,7-dicyanooctane, 2,8-dicyanononane, 1,6-dicyanodecane, 1,2-dicyanobenzene, 1,3-dicyano Benzene, 1,4-dicyanobenzene, 3,3 '-(ethylenedioxy) dipropionitrile, 3,3'-(ethylenedithio) dipropionitrile, 3,9-bis (2-cyanoethyl) -2,4 And 8,10-tetraoxaspiro [5,5] undecane, butane nitrile, phthalonitrile and the like. Among these, particularly preferred are succinonitrile, glutaronitrile and adiponitrile.
Also, specific examples of tricarbonitrile include pentane tricarbonitrile, propane tricarbonitrile, 1,3,5-hexane tricarbonitrile, 1,3,6-hexane tricarbonitrile, heptane tricarbonitrile, 2,3-propanetricarbonitrile, 1,3,5-pentanetricarbonitrile, cyclohexanetricarbonitrile, triscyanoethylamine, triscyanoethoxypropane, tricyanoethylene, tris (2-cyanoethyl) amine and the like Preferred are 1,3,6-hexane tricarbonitrile and cyclohexane tricarbonitrile, and most preferred is cyclohexane tricarbonitrile.
上記一般式（１ｂ）において、Ｒｃは、水素原子、ハロゲン原子、アルキル基、アルキル基の少なくとも一部の水素原子をハロゲン原子で置換した基、又は、ＮＣ－Ｒｃ１－Ｘｃ１－（Ｒｃ１はアルキレン基、Ｘｃ１は酸素原子又は硫黄原子を表す。）で表される基であり、Ｒｄ及びＲｅは、それぞれ独立して、水素原子、ハロゲン原子、アルキル基、又は、アルキル基の少なくとも一部の水素原子をハロゲン原子で置換した基である。
ハロゲン原子、アルキル基、及び、アルキル基の少なくとも一部の水素原子をハロゲン原子で置換した基については、上記一般式（１ａ）について例示したものが挙げられる。
上記ＮＣ－Ｒｃ１－Ｘｃ１－におけるＲｃ１はアルキレン基である。アルキレン基としては、炭素数１～３のアルキレン基が好ましい。
Ｒｃ、Ｒｄ及びＲｅは、それぞれ独立して、水素原子、ハロゲン原子、アルキル基、又は、アルキル基の少なくとも一部の水素原子をハロゲン原子で置換した基であることが好ましい。
Ｒｃ、Ｒｄ及びＲｅの少なくとも１つは、ハロゲン原子、又は、アルキル基の少なくとも一部の水素原子をハロゲン原子で置換した基であることが好ましく、フッ素原子、又は、アルキル基の少なくとも一部の水素原子をフッ素原子で置換した基であることがより好ましい。
Ｒｄ及びＲｅがアルキル基、又は、アルキル基の少なくとも一部の水素原子をハロゲン原子で置換した基である場合は、ＲｄとＲｅとが互いに結合して環構造（例えば、シクロヘキサン環）を形成していてもよい。 In the above general formula (1b), R c is a hydrogen atom, a halogen atom, an alkyl group, a group obtained by substituting at least a part of the hydrogen atoms of the alkyl group with a halogen atom, or NC-R c1 -X c1- (R c1 is an alkylene group, and X c1 is a group represented by an oxygen atom or a sulfur atom.) R d and R e each independently represent a hydrogen atom, a halogen atom, an alkyl group, or an alkyl group Are groups in which at least a part of hydrogen atoms are substituted by halogen atoms.
Examples of the halogen atom, the alkyl group, and the group in which at least a part of hydrogen atoms of the alkyl group is substituted with a halogen atom include those exemplified for the above general formula (1a).
The NC-R c1 -X c1 - in R c1 is an alkylene group. As the alkylene group, an alkylene group having 1 to 3 carbon atoms is preferable.
Each of R c , R d and R e is preferably independently a hydrogen atom, a halogen atom, an alkyl group, or a group obtained by substituting at least a part of hydrogen atoms of an alkyl group with a halogen atom.
At least one of R c , R d and R e is preferably a halogen atom or a group obtained by substituting at least a part of hydrogen atoms of an alkyl group with a halogen atom, and at least one of a fluorine atom or an alkyl group It is more preferable that it is a group in which a part of hydrogen atoms is substituted by a fluorine atom.
When R d and R e are an alkyl group or a group obtained by substituting at least a part of hydrogen atoms of an alkyl group with a halogen atom, R d and R e are bonded to each other to form a ring structure (eg, cyclohexane ring ) May be formed.
上記一般式（１ｂ）において、ｍは１～１０の整数である。ｍが２以上である場合、ｍ個のＲｄは全て同じであってもよく、少なくとも一部が異なっていてもよい。Ｒｅについても同様である。ｍは、２～７の整数が好ましく、２～５の整数がより好ましい。 In the above general formula (1b), m is an integer of 1 to 10. When m is 2 or more, the m Rds may be all the same or at least partially different. The same applies to R e . m is preferably an integer of 2 to 7, and more preferably an integer of 2 to 5.
上記一般式（１ｂ）で表されるニトリル化合物としては、アセトニトリル、プロピオニトリル、ブチロニトリル、イソブチロニトリル、バレロニトリル、イソバレロニトリル、ラウロニトリル、３－メトキシプロピオニトリル、２－メチルブチロニトリル、トリメチルアセトニトリル、ヘキサンニトリル、シクロペンタンカルボニトリル、シクロヘキサンカルボニトリル、フルオロアセトニトリル、ジフルオロアセトニトリル、トリフルオロアセトニトリル、２－フルオロプロピオニトリル、３－フルオロプロピオニトリル、２，２－ジフルオロプロピオニトリル、２，３－ジフルオロプロピオニトリル、３，３－ジフルオロプロピオニトリル、２，２，３－トリフルオロプロピオニトリル、３，３，３－トリフルオロプロピオニトリル、３，３’－オキシジプロピオニトリル、３，３’－チオジプロピオニトリル、ペンタフルオロプロピオニトリル、メトキシアセトニトリル、ベンゾニトリル等が例示できる。これらのうち、特に好ましいのは，３，３，３－トリフルオロプロピオニトリルである。 As the nitrile compound represented by the above general formula (1b), acetonitrile, propionitrile, butyronitrile, isobutyronitrile, valeronitrile, isovaleronitrile, lauronitrile, 3-methoxypropionitrile, 2-methylbutyro ro Nitrile, trimethylacetonitrile, hexanenitrile, cyclopentanecarbonitrile, cyclohexanecarbonitrile, fluoroacetonitrile, difluoroacetonitrile, trifluoroacetonitrile, 2-fluoropropionitrile, 3-fluoropropionitrile, 2,2-difluoropropionitrile, 2,3-Difluoropropionitrile, 3,3-difluoropropionitrile, 2,2,3-trifluoropropionitrile, 3,3,3-trifluoropropionitrile, 3 3'-oxy dipropionate nitrile, 3,3' thiodipropionitrile, pentafluoro propionitrile, methoxy acetonitrile, benzonitrile and the like. Among these, particularly preferred is 3,3,3-trifluoropropionitrile.
上記一般式（１ｃ）において、Ｒｆ、Ｒｇ、Ｒｈ及びＲｉは、それぞれ独立して、シアノ基（ＣＮ）を含む基、水素原子、ハロゲン原子、アルキル基、又は、アルキル基の少なくとも一部の水素原子をハロゲン原子で置換した基である。
ハロゲン原子、アルキル基、及び、アルキル基の少なくとも一部の水素原子をハロゲン原子で置換した基については、上記一般式（１ａ）について例示したものが挙げられる。
シアノ基を含む基としては、シアノ基のほか、アルキル基の少なくとも一部の水素原子をシアノ基で置換した基が挙げられる。この場合のアルキル基としては、上記一般式（１ａ）について例示したものが挙げられる。
Ｒｆ、Ｒｇ、Ｒｈ及びＲｉのうち少なくとも１つはシアノ基を含む基である。好ましくは、Ｒｆ、Ｒｇ、Ｒｈ及びＲｉのうち少なくとも２つがシアノ基を含む基であることであり、より好ましくは、Ｒｈ及びＲｉがシアノ基を含む基であることである。Ｒｈ及びＲｉがシアノ基を含む基である場合、Ｒｆ及びＲｇは、水素原子であることが好ましい。 In the above general formula (1c), R f , R g , R h and R i each independently represent at least a group including a cyano group (CN), a hydrogen atom, a halogen atom, an alkyl group or an alkyl group. It is a group in which a part of hydrogen atoms is replaced by a halogen atom.
Examples of the halogen atom, the alkyl group, and the group in which at least a part of hydrogen atoms of the alkyl group is substituted with a halogen atom include those exemplified for the above general formula (1a).
As a group containing a cyano group, the group which substituted at least one hydrogen atom of the alkyl group by the cyano group other than a cyano group is mentioned. As the alkyl group in this case, those exemplified for the above general formula (1a) can be mentioned.
At least one of R f , R g , R h and R i is a group containing a cyano group. Preferably, at least two of R f , R g , R h and R i are a group containing a cyano group, more preferably, R h and R i are a group containing a cyano group . When R h and R i are a group containing a cyano group, R f and R g are preferably a hydrogen atom.
上記一般式（１ｃ）において、ｌは１～３の整数である。ｌが２以上である場合、ｌ個のＲｆは全て同じであってもよく、少なくとも一部が異なっていてもよい。Ｒｇについても同様である。ｌは、１～２の整数が好ましい。 In the above general formula (1c), l is an integer of 1 to 3. When l is 2 or more, l R f may be all the same or at least a part may be different. The same applies to R g . l is preferably an integer of 1 to 2.
上記一般式（１ｃ）で表されるニトリル化合物としては、３－ヘキセンジニトリル、ムコノニトリル、マレオニトリル、フマロニトリル、アクリロニトリル、メタクリロニトリル、クロトノニトリル、３－メチルクロトノニトリル、２－メチル－２－ブテンニトリル、２－ペンテンニトリル、２－メチル－２－ペンテンニトリル、３－メチル－２－ペンテンニトリル、２－ヘキセンニトリル等が例示され、３－ヘキセンジニトリル、ムコノニトリルが好ましく、特に３－ヘキセンジニトリルが好ましい。 As the nitrile compound represented by the above general formula (1c), 3-hexenedinonitrile, mucononitrile, maleonitrile, fumaronitrile, acrylonitrile, methacrylonitrile, crotononitrile, 3-methylcrotononitrile, 2-methyl-2- Examples thereof include butenenitrile, 2-pentenenitrile, 2-methyl-2-pentenenitrile, 3-methyl-2-pentenenitrile, 2-hexenenitrile and the like, and 3-hexene dinitrile and mucononitrile are preferable, and 3-hexene di particular Nitriles are preferred.
上記ニトリル化合物の含有量は、電解液に対して０．２～７質量％であることが好ましい。これにより、電気化学デバイスの高電圧での高温保存特性、安全性を一層向上させることができる。上記ニトリル化合物の含有量の合計の下限は０．３質量％がより好ましく、０．５質量％が更に好ましい。上限は５質量％がより好ましく、２質量％が更に好ましく、０．５質量％が特に好ましい。 The content of the nitrile compound is preferably 0.2 to 7% by mass with respect to the electrolytic solution. This can further improve the high temperature storage characteristics and safety of the electrochemical device at high voltage. The lower limit of the total content of the nitrile compound is more preferably 0.3% by mass, and still more preferably 0.5% by mass. The upper limit is more preferably 5% by mass, still more preferably 2% by mass, and particularly preferably 0.5% by mass.
本発明の電解液は、イソシアナト基を有する化合物（以下、「イソシアネート」と略記する場合がある）を含んでもよい。上記イソシアネートとしては、特に限定されず、任意のイソシアネートを用いることができる。イソシアネートの例としては、モノイソシアネート類、ジイソシアネート類、トリイソシアネート類等が挙げられる。 The electrolytic solution of the present invention may contain a compound having an isocyanato group (hereinafter sometimes abbreviated as "isocyanate"). It does not specifically limit as said isocyanate, Arbitrary isocyanate can be used. Examples of the isocyanate include monoisocyanates, diisocyanates, triisocyanates and the like.
モノイソシアネート類の具体例としては、イソシアナトメタン、イソシアナトエタン、１－イソシアナトプロパン、１－イソシアナトブタン、１－イソシアナトペンタン、１－イソシアナトヘキサン、１－イソシアナトヘプタン、１－イソシアナトオクタン、１－イソシアナトノナン、１－イソシアナトデカン、イソシアナトシクロヘキサン、メトキシカルボニルイソシアネート、エトキシカルボニルイソシアネート、プロポキシカルボニルイソシアネート、ブトキシカルボニルイソシアネート、メトキシスルホニルイソシアネート、エトキシスルホニルイソシアネート、プロポキシスルホニルイソシアネート、ブトキシスルホニルイソシアネート、フルオロスルホニルイソシアネート、メチルイソシアネート、ブチルイソシアネート、フェニルイソシアネート、２－イソシアナトエチルアクリレート、２－イソシアナトエチルメタクリレート、エチルイソシアネート等が挙げられる。 Specific examples of monoisocyanates include isocyanatomethane, isocyanatoethane, 1-isocyanatopropane, 1-isocyanatobutane, 1-isocyanatopentane, 1-isocyanatohexane, 1-isocyanatoheptane, 1-isocyanate. Natooctane, 1-isocyanatononane, 1-isocyanatodecane, isocyanatocyclohexane, methoxycarbonyl isocyanate, ethoxycarbonyl isocyanate, propoxycarbonyl isocyanate, butoxycarbonyl isocyanate, methoxysulfonyl isocyanate, ethoxysulfonyl isocyanate, propoxysulfonyl isocyanate, butoxysulfonyl isocyanate , Fluorosulfonyl isocyanate, methyl isocyanate, butyl isocyanate, fe Le isocyanate, 2-isocyanatoethyl acrylate, 2-isocyanatoethyl methacrylate, ethyl isocyanate.
ジイソシアネート類の具体例としては、１，４－ジイソシアナトブタン、１，５－ジイソシアナトペンタン、１，６－ジイソシアナトヘキサン、１，７－ジイソシアナトヘプタン、１，８－ジイソシアナトオクタン、１，９－ジイソシアナトノナン、１，１０－ジイソシアナトデカン、１，３－ジイソシアナトプロペン、１，４－ジイソシアナト－２－ブテン、１，４－ジイソシアナト－２－フルオロブタン、１，４－ジイソシアナト－２，３－ジフルオロブタン、１，５－ジイソシアナト－２－ペンテン、１，５－ジイソシアナト－２－メチルペンタン、１，６－ジイソシアナト－２－ヘキセン、１，６－ジイソシアナト－３－ヘキセン、１，６－ジイソシアナト－３－フルオロヘキサン、１，６－ジイソシアナト－３，４－ジフルオロヘキサン、トルエンジイソシアネート、キシレンジイソシアネート、トリレンジイソシアネート、１，２－ビス（イソシアナトメチル）シクロヘキサン、１，３－ビス（イソシアナトメチル）シクロヘキサン、１，４－ビス（イソシアナトメチル）シクロヘキサン、１，２－ジイソシアナトシクロヘキサン、１，３－ジイソシアナトシクロヘキサン、１，４－ジイソシアナトシクロヘキサン、ジシクロヘキシルメタン－１，１’－ジイソシアネート、ジシクロヘキシルメタン－２，２’－ジイソシアネート、ジシクロヘキシルメタン－３，３’－ジイソシアネート、ジシクロヘキシルメタン－４，４’－ジイソシアネート、イソホロンジイソシアネート、ビシクロ［２．２．１］ヘプタン－２，５－ジイルビス（メチル＝イソシアネート）、ビシクロ［２．２．１］ヘプタン－２，６－ジイルビス（メチル＝イソシアネート）、２，４，４－トリメチルヘキサメチレンジイソシアナート、２，２，４－トリメチルヘキサメチレンジイソシアナート、ヘキサメチレンジイソシアネート、１，４－フェニレンジイソシアネート、オクタメチレンジイソシアネート、テトラメチレンジイソシアネート等が挙げられる。 Specific examples of diisocyanates include 1,4-diisocyanatobutane, 1,5-diisocyanatopentane, 1,6-diisocyanatohexane, 1,7-diisocyanatoheptane, 1,8-diisocyanate Natooctane, 1,9-diisocyanatononane, 1,10-diisocyanatodecane, 1,3-diisocyanatopropene, 1,4-diisocyanato-2-butene, 1,4-diisocyanato-2-fluorobutane 1,4-diisocyanato-2,3-difluorobutane, 1,5-diisocyanato-2-pentene, 1,5-diisocyanato-2-methylpentane, 1,6-diisocyanato-2-hexene, 1,6-diisocyanato -3-hexene, 1,6-diisocyanato-3-fluorohexane, 1,6-diisocyanato-3,4-difluorohexane Sun, toluene diisocyanate, xylene diisocyanate, tolylene diisocyanate, 1,2-bis (isocyanatomethyl) cyclohexane, 1,3-bis (isocyanatomethyl) cyclohexane, 1,4-bis (isocyanatomethyl) cyclohexane, 1, 2-diisocyanatocyclohexane, 1,3-diisocyanatocyclohexane, 1,4-diisocyanatocyclohexane, dicyclohexylmethane-1,1'-diisocyanate, dicyclohexylmethane-2,2'-diisocyanate, dicyclohexylmethane-3, 3'-diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, isophorone diisocyanate, bicyclo [2.2.1] heptane-2,5-diyl bis (methyl isocyanate), Black [2.2.1] heptane-2,6-diyl bis (methyl isocyanate), 2,4,4-trimethylhexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, hexamethylene diisocyanate And 1,4-phenylene diisocyanate, octamethylene diisocyanate, tetramethylene diisocyanate and the like.
トリイソシアネート類の具体例としては、１，６，１１－トリイソシアナトウンデカン、４－イソシアナトメチル－１，８－オクタメチレンジイソシアネート、１，３，５－トリイソシアネートメチルベンゼン、１，３，５－トリス（６－イソシアナトヘキサ－１－イル）－１，３，５－トリアジン－２，４，６（１Ｈ，３Ｈ，５Ｈ）－トリオン、４－（イソシアナトメチル）オクタメチレン＝ジイソシアネート等が挙げられる。 Specific examples of triisocyanates include 1,6,11-triisocyanatoundecane, 4-isocyanatomethyl-1,8-octamethylene diisocyanate, 1,3,5-triisocyanatomethylbenzene, 1,3,5 -Tris (6-isocyanatohex-1-yl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione, 4- (isocyanatomethyl) octamethylene diisocyanate etc. It can be mentioned.
中でも、１，６－ジイソシアナトヘキサン、１，３－ビス（イソシアナトメチル）シクロヘキサン、１，３，５－トリス（６－イソシアナトヘキサ－１－イル）－１，３，５－トリアジン－２，４，６（１Ｈ，３Ｈ，５Ｈ）－トリオン、２，４，４－トリメチルヘキサメチレンジイソシアナート、２，２，４－トリメチルヘキサメチレンジイソシアナートが、工業的に入手し易いものであり、電解液の製造コストが低く抑えられる点で好ましく、また技術的な観点からも安定な被膜状の構造物の形成に寄与することができ、より好適に用いられる。 Among them, 1,6-diisocyanatohexane, 1,3-bis (isocyanatomethyl) cyclohexane, 1,3,5-tris (6-isocyanatohexa-1-yl) -1,3,5-triazine- 2,4,6 (1H, 3H, 5H) -trione, 2,4,4-trimethylhexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate are industrially easy to obtain It is preferable in that the production cost of the electrolytic solution can be kept low, and from the technical point of view it can contribute to the formation of a stable film-like structure and is more preferably used.
イソシアネートの含有量は、特に限定されず、本発明の効果を著しく損なわない限り任意であるが、電解液に対して、好ましくは０．００１質量％以上、１．０質量％以下である。イソシアネートの含有量がこの下限以上であると、非水系電解液二次電池に、十分なサイクル特性向上効果をもたらすことができる。また、この上限以下であると、非水系電解液二次電池の初期の抵抗増加を避けることができる。イソシアネートの含有量は、より好ましくは０．０１質量％以上、更に好ましくは０．１質量％以上、特に好ましくは０．２質量％以上、また、より好ましくは０．８質量％以下、更に好ましくは０．７質量％以下、特に好ましくは０．６質量％以下である。 The content of the isocyanate is not particularly limited and is optional as long as the effects of the present invention are not significantly impaired, but the content is preferably 0.001% by mass or more and 1.0% by mass or less with respect to the electrolytic solution. When the content of the isocyanate is at least the lower limit, the non-aqueous electrolyte secondary battery can have a sufficient effect of improving the cycle characteristics. Moreover, the initial stage resistance increase of a non-aqueous electrolyte solution secondary battery can be avoided as it is below this upper limit. The content of isocyanate is more preferably 0.01% by mass or more, still more preferably 0.1% by mass or more, particularly preferably 0.2% by mass or more, and more preferably 0.8% by mass or less, more preferably Is at most 0.7% by mass, particularly preferably at most 0.6% by mass.
本発明の電解液は、環状スルホン酸エステルを含んでもよい。環状スルホン酸エステルとしては、特に限定されず、任意の環状スルホン酸エステルを用いることができる。環状スルホン酸エステルの例としては、飽和環状スルホン酸エステル、不飽和環状スルホン酸エステル、飽和環状ジスルホン酸エステル、不飽和環状ジスルホン酸エステル等が挙げられる。 The electrolytic solution of the present invention may contain a cyclic sulfonic acid ester. The cyclic sulfonic acid ester is not particularly limited, and any cyclic sulfonic acid ester can be used. Examples of cyclic sulfonic acid esters include saturated cyclic sulfonic acid esters, unsaturated cyclic sulfonic acid esters, saturated cyclic disulfonic acid esters, unsaturated cyclic disulfonic acid esters and the like.
飽和環状スルホン酸エステルの具体例としては、１，３－プロパンスルトン、１－フルオロ－１，３－プロパンスルトン、２－フルオロ－１，３－プロパンスルトン、３－フルオロ－１，３－プロパンスルトン、１－メチル－１，３－プロパンスルトン、２－メチル－１，３－プロパンスルトン、３－メチル－１，３－プロパンスルトン、１，３－ブタンスルトン、１，４－ブタンスルトン、１－フルオロ－１，４－ブタンスルトン、２－フルオロ－１，４－ブタンスルトン、３－フルオロ－１，４－ブタンスルトン、４－フルオロ－１，４－ブタンスルトン、１－メチル－１，４－ブタンスルトン、２－メチル－１，４－ブタンスルトン、３－メチル－１，４－ブタンスルトン、４－メチル－１，４－ブタンスルトン、２，４－ブタンスルトン等が挙げられる。 Specific examples of the saturated cyclic sulfonic acid ester include 1,3-propane sultone, 1-fluoro-1,3-propane sultone, 2-fluoro-1,3-propane sultone, 3-fluoro-1,3-propane sultone 1-methyl-1,3-propanesultone, 2-methyl-1,3-propanesultone, 3-methyl-1,3-propanesultone, 1,3-butanesultone, 1,4-butanesultone, 1-fluoro-, 1,4-butane sultone, 2-fluoro-1,4-butane sultone, 3-fluoro-1,4-butane sultone, 4-fluoro-1,4-butane sultone, 1-methyl-1,4-butane sultone, 2-methyl- 1,4-butane sultone, 3-methyl-1,4-butane sultone, 4-methyl-1,4-butane sultone, 2,4-butane sultone Emissions, and the like.
不飽和環状スルホン酸エステルの具体例としては、１－プロペン－１，３－スルトン、２－プロペン－１，３－スルトン、１－フルオロ－１－プロペン－１，３－スルトン、２－フルオロ－１－プロペン－１，３－スルトン、３－フルオロ－１－プロペン－１，３－スルトン、１－フルオロ－２－プロペン－１，３－スルトン、２－フルオロ－２－プロペン－１，３－スルトン、３－フルオロ－２－プロペン－１，３－スルトン、１－メチル－１－プロペン－１，３－スルトン、２－メチル－１－プロペン－１，３－スルトン、３－メチル－１－プロペン－１，３－スルトン、１－メチル－２－プロペン－１，３－スルトン、２－メチル－２－プロペン－１，３－スルトン、３－メチル－２－プロペン－１，３－スルトン、１－ブテン－１，４－スルトン、２－ブテン－１，４－スルトン、３－ブテン－１，４－スルトン、１－フルオロ－１－ブテン－１，４－スルトン、２－フルオロ－１－ブテン－１，４－スルトン、３－フルオロ－１－ブテン－１，４－スルトン、４－フルオロ－１－ブテン－１，４－スルトン、１－フルオロ－２－ブテン－１，４－スルトン、２－フルオロ－２－ブテン－１，４－スルトン、３－フルオロ－２－ブテン－１，４－スルトン、４－フルオロ－２－ブテン－１，４－スルトン、１，３－プロペンスルトン、１－フルオロ－３－ブテン－１，４－スルトン、２－フルオロ－３－ブテン－１，４－スルトン、３－フルオロ－３－ブテン－１，４－スルトン、４－フルオロ－３－ブテン－１，４－スルトン、１－メチル－１－ブテン－１，４－スルトン、２－メチル－１－ブテン－１，４－スルトン、３－メチル－１－ブテン－１，４－スルトン、４－メチル－１－ブテン－１，４－スルトン、１－メチル－２－ブテン－１，４－スルトン、２－メチル－２－ブテン－１，４－スルトン、３－メチル－２－ブテン－１，４－スルトン、４－メチル－２－ブテン－１，４－スルトン、１－メチル－３－ブテン－１，４－スルトン、２－メチル－３－ブテン－１，４－スルトン、３－メチル－３－ブテン－１，４－スルトン、４－メチル－３－ブテン－１４－スルトン等が挙げられる。 Specific examples of the unsaturated cyclic sulfonic acid ester include 1-propene-1,3-sultone, 2-propene-1,3-sultone, 1-fluoro-1-propene-1,3-sultone, 2-fluoro- 1-propene-1,3-sultone, 3-fluoro-1-propene-1,3-sultone, 1-fluoro-2-propene-1,3-sultone, 2-fluoro-2-propene-1,3- Sultone, 3-fluoro-2-propene-1,3-sultone, 1-methyl-1-propene-1,3-sultone, 2-methyl-1-propene-1,3-sultone, 3-methyl-1- Propene-1,3-sultone, 1-methyl-2-propene-1,3-sultone, 2-methyl-2-propene-1,3-sultone, 3-methyl-2-propene-1,3-sultone, 1-butene-1, -Sultone, 2-butene-1,4-sultone, 3-butene-1,4-sultone, 1-fluoro-1-butene-1,4-sultone, 2-fluoro-1-butene-1,4-sultone , 3-fluoro-1-butene-1,4-sultone, 4-fluoro-1-butene-1,4-sultone, 1-fluoro-2-butene-1,4-sultone, 2-fluoro-2-butene -1,4-Sultone, 3-Fluoro-2-butene-1,4-sultone, 4-Fluoro-2-butene-1,4-sultone, 1,3-propene sultone, 1-Fluoro-3-butene- 1,4-sultone, 2-fluoro-3-butene-1,4-sultone, 3-fluoro-3-butene-1,4-sultone, 4-fluoro-3-butene-1,4-sultone, 1- Methyl-1-butene-1,4-sult , 2-Methyl-1-butene-1,4-sultone, 3-methyl-1-butene-1,4-sultone, 4-methyl-1-butene-1,4-sultone, 1-methyl-2-butene -1,4-Sultone, 2-Methyl-2-butene-1,4-Sultone, 3-Methyl-2-butene-1,4-Sultone, 4-Methyl-2-butene-1,4-Sultone, 1 -Methyl-3-butene-1,4-sultone, 2-methyl-3-butene-1,4-sultone, 3-methyl-3-butene-1,4-sultone, 4-methyl-3-butene-14 -Sultone etc. are mentioned.
中でも、１，３－プロパンスルトン、１－フルオロ－１，３－プロパンスルトン、２－フルオロ－１，３－プロパンスルトン、３－フルオロ－１，３－プロパンスルトン、１－プロペン－１，３－スルトンが、入手の容易さや安定な被膜状の構造物の形成に寄与することができる点から、より好適に用いられる。環状スルホン酸エステルの含有量は、特に限定されず、本発明の効果を著しく損なわない限り任意であるが、電解液に対して、好ましくは０．００１質量％以上、３．０質量％以下である。 Among them, 1,3-propane sultone, 1-fluoro-1,3-propane sultone, 2-fluoro-1,3-propane sultone, 3-fluoro-1,3-propane sultone, 1-propene-1,3- Sultone is more preferably used in that it can contribute to the availability and formation of a stable film-like structure. The content of the cyclic sulfonic acid ester is not particularly limited and is optional as long as the effects of the present invention are not significantly impaired, but preferably 0.001% by mass or more and 3.0% by mass or less with respect to the electrolytic solution. is there.
環状スルホン酸エステルの含有量がこの下限以上であると、非水系電解液二次電池に、十分なサイクル特性向上効果をもたらすことができる。また、この上限以下であると、非水系電解液二次電池の製造コストの増加を避けることができる。環状スルホン酸エステルの含有量は、より好ましくは０．０１質量％以上、更に好ましくは０．１質量％以上、特に好ましくは０．２質量％以上、また、より好ましくは２．５質量％以下、更に好ましくは２．０質量％以下、特に好ましくは１．８質量％以下である。 When the content of the cyclic sulfonic acid ester is at least the lower limit, a sufficient improvement in cycle characteristics can be provided to the non-aqueous electrolyte secondary battery. Moreover, the increase in the manufacturing cost of a non-aqueous electrolyte solution secondary battery can be avoided as it is below this upper limit. The content of the cyclic sulfonic acid ester is more preferably 0.01% by mass or more, still more preferably 0.1% by mass or more, particularly preferably 0.2% by mass or more, and more preferably 2.5% by mass or less More preferably, it is at most 2.0 mass%, particularly preferably at most 1.8 mass%.
本発明の電解液は、更に、重量平均分子量が２０００～４０００であり、末端に－ＯＨ、－ＯＣＯＯＨ、又は、－ＣＯＯＨを有するポリエチレンオキシドを含有してもよい。
このような化合物を含有することにより、電極界面の安定性が向上し、電気化学デバイスの特性を向上させることができる。
上記ポリエチレンオキシドとしては、例えば、ポリエチレンオキシドモノオール、ポリエチレンオキシドカルボン酸、ポリエチレンオキシドジオール、ポリエチレンオキシドジカルボン酸、ポリエチレンオキシドトリオール、ポリエチレンオキシドトリカルボン酸等が挙げられる。これらは単独で使用してもよいし、２種以上を併用してもよい。
なかでも、電気化学デバイスの特性がより良好となる点で、ポリエチレンオキシドモノオールとポリエチレンオキシドジオールの混合物、及び、ポリエチレンカルボン酸とポリエチレンジカルボン酸の混合物であることが好ましい。 The electrolytic solution of the present invention may further contain polyethylene oxide having a weight average molecular weight of 2000 to 4000 and having -OH, -OCOOH or -COOH at the end.
By containing such a compound, the stability of the electrode interface can be improved, and the characteristics of the electrochemical device can be improved.
As said polyethylene oxide, polyethylene oxide monool, polyethylene oxide carboxylic acid, polyethylene oxide diol, polyethylene oxide dicarboxylic acid, polyethylene oxide triol, polyethylene oxide tricarboxylic acid etc. are mentioned, for example. These may be used alone or in combination of two or more.
Among them, a mixture of polyethylene oxide monool and polyethylene oxide diol, and a mixture of polyethylene carboxylic acid and polyethylene dicarboxylic acid are preferable in that the characteristics of the electrochemical device become better.
上記ポリエチレンオキシドの重量平均分子量が小さすぎると、酸化分解されやすくなるおそれがある。上記重量平均分子量は、３０００～４０００がより好ましい。
上記重量平均分子量は、ゲルパーミエーションクロマトグラフィー（ＧＰＣ）法によるポリスチレン換算により測定することができる。 If the weight average molecular weight of the above-mentioned polyethylene oxide is too small, there is a possibility that it is easy to be oxidatively decomposed. The weight average molecular weight is more preferably 3,000 to 4,000.
The said weight average molecular weight can be measured by polystyrene conversion by gel permeation chromatography (GPC) method.
上記ポリエチレンオキシドの含有量は、電解液中１×１０－６～１×１０－２ｍｏｌ／ｋｇであることが好ましい。上記ポリエチレンオキシドの含有量が多すぎると、電気化学デバイスの特性を損なうおそれがある。
上記ポリエチレンオキシドの含有量は、５×１０－６ｍｏｌ／ｋｇ以上であることがより好ましい。 The content of the polyethylene oxide is preferably 1 × 10 −6 to 1 × 10 −2 mol / kg in the electrolytic solution. If the content of the polyethylene oxide is too high, the properties of the electrochemical device may be impaired.
The content of the polyethylene oxide is more preferably 5 × 10 −6 mol / kg or more.
本発明の電解液は、添加剤として、更に、フッ素化飽和環状カーボネート、不飽和環状カーボネート、過充電防止剤、その他の公知の助剤等を含有していてもよい。これにより、電気化学デバイスの特性の低下を抑制することができる。 The electrolytic solution of the present invention may further contain, as an additive, a fluorinated saturated cyclic carbonate, an unsaturated cyclic carbonate, an overcharge inhibitor, other known auxiliary agents and the like. Thereby, the deterioration of the characteristics of the electrochemical device can be suppressed.
フッ素化飽和環状カーボネートとしては、上述した一般式（Ａ）で示される化合物が挙げられる。なかでも、フルオロエチレンカーボネート、４，５－ジフルオロ－１，３－ジオキソラン－２－オン、２，２，３，３，３－ペンタフルオロプロピルエチレンカーボネート（４－（２，２，３，３，３－ペンタフルオロ－プロピル）－［１，３］ジオキソラン－２－オン）が好ましい。フッ素化飽和環状カーボネートは、１種を単独で用いてもよく、２種以上を任意の組み合わせ及び比率で併用してもよい。 Examples of the fluorinated saturated cyclic carbonate include the compounds represented by the general formula (A) described above. Among them, fluoroethylene carbonate, 4,5-difluoro-1,3-dioxolan-2-one, 2,2,3,3,3-pentafluoropropyl ethylene carbonate (4- (2,2,3,3, 3-Pentafluoro-propyl)-[1,3] dioxolan-2-one) is preferred. The fluorinated saturated cyclic carbonate may be used alone or in any combination of two or more in any proportion.
上記フッ素化飽和環状カーボネートの含有量は、上記電解液に対して、０．００１～１０質量％であることが好ましく、０．０１～５質量％であることがより好ましく、０．１～３質量％であることが更に好ましい。 The content of the fluorinated saturated cyclic carbonate is preferably 0.001 to 10% by mass, more preferably 0.01 to 5% by mass, with respect to the electrolytic solution. More preferably, it is mass%.
不飽和環状カーボネートとしては、ビニレンカーボネート類、芳香環又は炭素－炭素二重結合又は炭素－炭素三重結合を有する置換基で置換されたエチレンカーボネート類、フェニルカーボネート類、ビニルカーボネート類、アリルカーボネート類、カテコールカーボネート類等が挙げられる。 Examples of unsaturated cyclic carbonates include vinylene carbonates, ethylene carbonates substituted with a substituent having an aromatic ring or a carbon-carbon double bond or a carbon-carbon triple bond, phenyl carbonates, vinyl carbonates, allyl carbonates, And catechol carbonates.
ビニレンカーボネート類としては、ビニレンカーボネート、メチルビニレンカーボネート、４，５－ジメチルビニレンカーボネート、フェニルビニレンカーボネート、４，５－ジフェニルビニレンカーボネート、ビニルビニレンカーボネート、４，５－ジビニルビニレンカーボネート、アリルビニレンカーボネート、４，５－ジアリルビニレンカーボネート、４－フルオロビニレンカーボネート、４－フルオロ－５－メチルビニレンカーボネート、４－フルオロ－５－フェニルビニレンカーボネート、４－フルオロ－５－ビニルビニレンカーボネート、４－アリル－５－フルオロビニレンカーボネート、エチニルエチレンカーボネート、プロパルギルエチレンカーボネート、メチルビニレンカーボネート、ジメチルビニレンカーボネート等が挙げられる。 As vinylene carbonates, vinylene carbonate, methylvinylene carbonate, 4,5-dimethylvinylene carbonate, phenylvinylene carbonate, 4,5-diphenylvinylene carbonate, vinylvinylene carbonate, 4,5-divinylvinylene carbonate, allylvinylene carbonate, 4 , 5-diallylvinylene carbonate, 4-fluorovinylene carbonate, 4-fluoro-5-methylvinylene carbonate, 4-fluoro-5-phenylvinylene carbonate, 4-fluoro-5-vinylvinylene carbonate, 4-allyl-5-fluoro Vinylene carbonate, ethynyl ethylene carbonate, propargyl ethylene carbonate, methyl vinylene carbonate, dimethyl vinylene carbonate, etc. It is below.
芳香環又は炭素－炭素二重結合又は炭素－炭素三重結合を有する置換基で置換されたエチレンカーボネート類の具体例としては、ビニルエチレンカーボネート、４，５－ジビニルエチレンカーボネート、４－メチル－５－ビニルエチレンカーボネート、４－アリル－５－ビニルエチレンカーボネート、エチニルエチレンカーボネート、４，５－ジエチニルエチレンカーボネート、４－メチル－５－エチニルエチレンカーボネート、４－ビニル－５－エチニルエチレンカーボネート、４－アリル－５－エチニルエチレンカーボネート、フェニルエチレンカーボネート、４，５－ジフェニルエチレンカーボネート、４－フェニル－５－ビニルエチレンカーボネート、４－アリル－５－フェニルエチレンカーボネート、アリルエチレンカーボネート、４，５－ジアリルエチレンカーボネート、４－メチル－５－アリルエチレンカーボネート、４－メチレン－１，３－ジオキソラン－２－オン、４，５－ジメチレン－１，３－ジオキソラン－２－オン、４－メチル－５－アリルエチレンカーボネート等が挙げられる。 Specific examples of ethylene carbonates substituted with a substituent having an aromatic ring or a carbon-carbon double bond or a carbon-carbon triple bond include vinyl ethylene carbonate, 4,5-divinyl ethylene carbonate, 4-methyl-5- Vinyl ethylene carbonate, 4-allyl-5-vinyl ethylene carbonate, ethynyl ethylene carbonate, 4,5-diethynyl ethylene carbonate, 4-methyl-5-ethynyl ethylene carbonate, 4-vinyl-5-ethynyl ethylene carbonate, 4-allyl -5-ethynyl ethylene carbonate, phenyl ethylene carbonate, 4,5-diphenyl ethylene carbonate, 4-phenyl-5-vinyl ethylene carbonate, 4-allyl-5-phenyl ethylene carbonate, allyl ethylene carbonate 4,5-Diallylethylene carbonate, 4-methyl-5-allylethylene carbonate, 4-methylene-1,3-dioxolan-2-one, 4,5-dimethylene-1,3-dioxolan-2-one, 4- Methyl 5-allyl ethylene carbonate and the like can be mentioned.
なかでも、不飽和環状カーボネートとしては、ビニレンカーボネート、メチルビニレンカーボネート、４，５－ジメチルビニレンカーボネート、ビニルビニレンカーボネート、４，５－ビニルビニレンカーボネート、アリルビニレンカーボネート、４，５－ジアリルビニレンカーボネート、ビニルエチレンカーボネート、４，５－ジビニルエチレンカーボネート、４－メチル－５－ビニルエチレンカーボネート、アリルエチレンカーボネート、４，５－ジアリルエチレンカーボネート、４－メチル－５－アリルエチレンカーボネート、４－アリル－５－ビニルエチレンカーボネート、エチニルエチレンカーボネート、４，５－ジエチニルエチレンカーボネート、４－メチル－５－エチニルエチレンカーボネート、４－ビニル－５－エチニルエチレンカーボネートが好ましい。また、ビニレンカーボネート、ビニルエチレンカーボネート、エチニルエチレンカーボネートは更に安定な界面保護被膜を形成するので、特に好ましく、ビニレンカーボネートが最も好ましい。 Among them, as unsaturated cyclic carbonates, vinylene carbonate, methylvinylene carbonate, 4,5-dimethylvinylene carbonate, vinylvinylene carbonate, 4,5-vinylvinylene carbonate, allylvinylene carbonate, 4,5-diallylvinylene carbonate, vinyl Ethylene carbonate, 4,5-divinyl ethylene carbonate, 4-methyl-5-vinyl ethylene carbonate, allyl ethylene carbonate, 4,5-diallyl ethylene carbonate, 4-methyl-5-allyl ethylene carbonate, 4-allyl-5-vinyl Ethylene carbonate, ethynyl ethylene carbonate, 4,5-diethynyl ethylene carbonate, 4-methyl-5-ethynyl ethylene carbonate, 4-vinyl-5-ethynyl ether Ren carbonate is preferred. Further, vinylene carbonate, vinyl ethylene carbonate and ethynyl ethylene carbonate are particularly preferable because they form a more stable interfacial protective film, and vinylene carbonate is most preferable.
不飽和環状カーボネートの分子量は、特に制限されず、本発明の効果を著しく損なわない限り任意である。分子量は、好ましくは、５０以上、２５０以下である。この範囲であれば、電解液に対する不飽和環状カーボネートの溶解性を確保しやすく、本発明の効果が十分に発現されやすい。不飽和環状カーボネートの分子量は、より好ましくは８０以上であり、また、より好ましくは１５０以下である。 The molecular weight of the unsaturated cyclic carbonate is not particularly limited, and is arbitrary unless the effects of the present invention are significantly impaired. The molecular weight is preferably 50 or more and 250 or less. Within this range, the solubility of the unsaturated cyclic carbonate in the electrolytic solution can be easily secured, and the effects of the present invention can be sufficiently exhibited. The molecular weight of the unsaturated cyclic carbonate is more preferably 80 or more, and more preferably 150 or less.
不飽和環状カーボネートの製造方法は、特に制限されず、公知の方法を任意に選択して製造することが可能である。 The method for producing the unsaturated cyclic carbonate is not particularly limited, and any known method can be selected for production.
不飽和環状カーボネートは、１種を単独で用いても、２種以上を任意の組み合わせ及び比率で併用してもよい。 The unsaturated cyclic carbonates may be used alone or in any combination of two or more in any proportion.
上記不飽和環状カーボネートの含有量は、特に制限されず、本発明の効果を著しく損なわない限り任意である。上記不飽和環状カーボネートの含有量は、電解液１００質量％中０．００１質量％以上が好ましく、より好ましくは０．０１質量％以上、更に好ましくは０．１質量％以上である。また、上記含有量は、５質量％以下が好ましく、より好ましくは４質量％以下、更に好ましくは３質量％以下である。上記範囲内であれば、電解液を用いた電気化学デバイスが十分なサイクル特性向上効果を発現しやすく、また、高温保存特性が低下し、ガス発生量が多くなり、放電容量維持率が低下するといった事態を回避しやすい。 The content of the unsaturated cyclic carbonate is not particularly limited, and is arbitrary unless the effects of the present invention are significantly impaired. The content of the unsaturated cyclic carbonate is preferably 0.001% by mass or more, more preferably 0.01% by mass or more, and still more preferably 0.1% by mass or more in 100% by mass of the electrolytic solution. The content is preferably 5% by mass or less, more preferably 4% by mass or less, and still more preferably 3% by mass or less. Within the above range, an electrochemical device using an electrolytic solution is likely to exhibit a sufficient cycle characteristics improvement effect, and also the high temperature storage characteristics deteriorate, the amount of gas generation increases, and the discharge capacity retention rate decreases. It is easy to avoid such situations.
不飽和環状カーボネートとしては、上述のような非フッ素化不飽和環状カーボネートの他、フッ素化不飽和環状カーボネートも好適に用いることができる。
フッ素化不飽和環状カーボネートは、不飽和結合とフッ素原子とを有する環状カーボネートである。フッ素化不飽和環状カーボネートが有するフッ素原子の数は１以上があれば、特に制限されない。中でもフッ素原子が通常６以下、好ましくは４以下であり、１個又は２個のものが最も好ましい。 As the unsaturated cyclic carbonate, in addition to the non-fluorinated unsaturated cyclic carbonate as described above, a fluorinated unsaturated cyclic carbonate can also be suitably used.
The fluorinated unsaturated cyclic carbonate is a cyclic carbonate having an unsaturated bond and a fluorine atom. The number of fluorine atoms in the fluorinated unsaturated cyclic carbonate is not particularly limited as long as it is 1 or more. Among them, the number of fluorine atoms is usually 6 or less, preferably 4 or less, and one or two are most preferable.
フッ素化不飽和環状カーボネートとしては、フッ素化ビニレンカーボネート誘導体、芳香環又は炭素－炭素二重結合を有する置換基で置換されたフッ素化エチレンカーボネート誘導体等が挙げられる。 Examples of the fluorinated unsaturated cyclic carbonate include fluorinated vinylene carbonate derivatives, fluorinated ethylene carbonate derivatives substituted with a substituent having an aromatic ring or a carbon-carbon double bond, and the like.
フッ素化ビニレンカーボネート誘導体としては、４－フルオロビニレンカーボネート、４－フルオロ－５－メチルビニレンカーボネート、４－フルオロ－５－フェニルビニレンカーボネート、４－アリル－５－フルオロビニレンカーボネート、４－フルオロ－５－ビニルビニレンカーボネート等が挙げられる。 As fluorinated vinylene carbonate derivatives, 4-fluorovinylene carbonate, 4-fluoro-5-methylvinylene carbonate, 4-fluoro-5-phenylvinylene carbonate, 4-allyl-5-fluorovinylene carbonate, 4-fluoro-5- And vinyl vinylene carbonate and the like.
芳香環又は炭素－炭素二重結合を有する置換基で置換されたフッ素化エチレンカーボネート誘導体としては、４－フルオロ－４－ビニルエチレンカーボネート、４－フルオロ－４－アリルエチレンカーボネート、４－フルオロ－５－ビニルエチレンカーボネート、４－フルオロ－５－アリルエチレンカーボネート、４，４－ジフルオロ－４－ビニルエチレンカーボネート、４，４－ジフルオロ－４－アリルエチレンカーボネート、４，５－ジフルオロ－４－ビニルエチレンカーボネート、４，５－ジフルオロ－４－アリルエチレンカーボネート、４－フルオロ－４，５－ジビニルエチレンカーボネート、４－フルオロ－４，５－ジアリルエチレンカーボネート、４，５－ジフルオロ－４，５－ジビニルエチレンカーボネート、４，５－ジフルオロ－４，５－ジアリルエチレンカーボネート、４－フルオロ－４－フェニルエチレンカーボネート、４－フルオロ－５－フェニルエチレンカーボネート、４，４－ジフルオロ－５－フェニルエチレンカーボネート、４，５－ジフルオロ－４－フェニルエチレンカーボネート等が挙げられる。 As the fluorinated ethylene carbonate derivative substituted by a substituent having an aromatic ring or a carbon-carbon double bond, 4-fluoro-4-vinyl ethylene carbonate, 4-fluoro-4-allyl ethylene carbonate, 4-fluoro-5 -Vinyl ethylene carbonate, 4-fluoro-5-allyl ethylene carbonate, 4,4-difluoro-4-vinyl ethylene carbonate, 4,4-difluoro-4-allyl ethylene carbonate, 4,5-difluoro-4-vinyl ethylene carbonate 4,5-Difluoro-4-allyl ethylene carbonate, 4-fluoro-4,5-divinyl ethylene carbonate, 4-fluoro-4,5-diallyl ethylene carbonate, 4,5-difluoro-4,5-divinyl ethylene carbonate , 4,5-Diful 4- 4, 5-diallyl ethylene carbonate, 4-fluoro 4-phenyl ethylene carbonate, 4- fluoro 5- phenyl ethylene carbonate, 4, 4- difluoro 5- phenyl ethylene carbonate, 4, 5- difluoro-4- 4- Phenyl ethylene carbonate etc. are mentioned.
なかでも、フッ素化不飽和環状カーボネートとしては、４－フルオロビニレンカーボネート、４－フルオロ－５－メチルビニレンカーボネート、４－フルオロ－５－ビニルビニレンカーボネート、４－アリル－５－フルオロビニレンカーボネート、４－フルオロ－４－ビニルエチレンカーボネート、４－フルオロ－４－アリルエチレンカーボネート、４－フルオロ－５－ビニルエチレンカーボネート、４－フルオロ－５－アリルエチレンカーボネート、４，４－ジフルオロ－４－ビニルエチレンカーボネート、４，４－ジフルオロ－４－アリルエチレンカーボネート、４，５－ジフルオロ－４－ビニルエチレンカーボネート、４，５－ジフルオロ－４－アリルエチレンカーボネート、４－フルオロ－４，５－ジビニルエチレンカーボネート、４－フルオロ－４，５－ジアリルエチレンカーボネート、４，５－ジフルオロ－４，５－ジビニルエチレンカーボネート、４，５－ジフルオロ－４，５－ジアリルエチレンカーボネートが、安定な界面保護被膜を形成するので、より好適に用いられる。 Among them, 4-fluorovinylene carbonate, 4-fluoro-5-methylvinylene carbonate, 4-fluoro-5-vinylvinylene carbonate, 4-allyl-5-fluorovinylene carbonate, and the like as the fluorinated unsaturated cyclic carbonate Fluoro-4-vinyl ethylene carbonate, 4-fluoro-4-allyl ethylene carbonate, 4-fluoro-5-vinyl ethylene carbonate, 4-fluoro-5-allyl ethylene carbonate, 4,4-difluoro-4-vinyl ethylene carbonate, 4,4-Difluoro-4-allyl ethylene carbonate, 4,5-difluoro-4-vinyl ethylene carbonate, 4,5-difluoro-4-allyl ethylene carbonate, 4-fluoro-4,5-divinyl ethylene carbonate, -Fluoro-4,5-diallylethylene carbonate, 4,5-difluoro-4,5-divinylethylene carbonate, 4,5-difluoro-4,5-diallylethylene carbonate form a stable interfacial protective film, It is more preferably used.
フッ素化不飽和環状カーボネートの分子量は、特に制限されず、本発明の効果を著しく損なわない限り任意である。分子量は、好ましくは、５０以上であり、また、５００以下である。この範囲であれば、電解液に対するフッ素化不飽和環状カーボネートの溶解性を確保しやすい。 The molecular weight of the fluorinated unsaturated cyclic carbonate is not particularly limited and is arbitrary unless the effects of the present invention are significantly impaired. The molecular weight is preferably 50 or more and 500 or less. Within this range, it is easy to ensure the solubility of the fluorinated unsaturated cyclic carbonate in the electrolytic solution.
フッ素化不飽和環状カーボネートの製造方法は、特に制限されず、公知の方法を任意に選択して製造することが可能である。分子量は、より好ましくは１００以上であり、また、より好ましくは２００以下である。 The method for producing the fluorinated unsaturated cyclic carbonate is not particularly limited, and any known method can be selected for production. The molecular weight is more preferably 100 or more, and more preferably 200 or less.
フッ素化不飽和環状カーボネートは、１種を単独で用いてもよく、２種以上を任意の組み合わせ及び比率で併用してもよい。また、フッ素化不飽和環状カーボネートの含有量は、特に制限されず、本発明の効果を著しく損なわない限り任意である。フッ素化不飽和環状カーボネートの含有量は、通常、電解液１００質量％中、好ましくは０．００１質量％以上、より好ましくは０．０１質量％以上、更に好ましくは０．１質量％以上であり、また、好ましくは５質量％以下、より好ましくは４質量％以下、更に好ましくは３質量％以下である。この範囲内であれば、電解液を用いた電気化学デバイスが十分なサイクル特性向上効果を発現しやすく、また、高温保存特性が低下し、ガス発生量が多くなり、放電容量維持率が低下するといった事態を回避しやすい。 The fluorinated unsaturated cyclic carbonates may be used alone or in any combination of two or more in any proportion. Further, the content of the fluorinated unsaturated cyclic carbonate is not particularly limited, and is optional unless the effects of the present invention are significantly impaired. The content of the fluorinated unsaturated cyclic carbonate is usually preferably 0.001% by mass or more, more preferably 0.01% by mass or more, and still more preferably 0.1% by mass or more in 100% by mass of the electrolytic solution. Moreover, preferably it is 5 mass% or less, More preferably, it is 4 mass% or less, More preferably, it is 3 mass% or less. Within this range, an electrochemical device using an electrolytic solution is likely to exhibit a sufficient cycle characteristics improvement effect, and also the high temperature storage characteristics deteriorate, the gas generation amount increases, and the discharge capacity retention rate decreases. It is easy to avoid such situations.
本発明の電解液は、三重結合を有する化合物を含んでいてもよい。分子内に三重結合を１つ以上有している化合物であれば特にその種類は限定されない。
三重結合を有する化合物の具体例としては、例えば、以下の化合物が挙げられる。
１－ペンチン、２－ペンチン、１－ヘキシン、２－ヘキシン、３－ヘキシン、１－ヘプチン、２－ヘプチン、３－ヘプチン、１－オクチン、２－オクチン、３－オクチン、４－オクチン、１－ノニン、２－ノニン、３－ノニン、４－ノニン、１－ドデシン、２－ドデシン、３－ドデシン、４－ドデシン、５－ドデシン、フェニルアセチレン、１－フェニル－１－プロピン、１－フェニル－２－プロピン、１－フェニル－１－ブチン、４－フェニル－１－ブチン、４－フェニル－１－ブチン、１－フェニル－１－ペンチン、５－フェニル－１－ペンチン、１－フェニル－１－ヘキシン、６－フェニル－１－ヘキシン、ジフェニルアセチレン、４－エチニルトルエン、ジシクロヘキシルアセチレン等の炭化水素化合物； The electrolytic solution of the present invention may contain a compound having a triple bond. The type is not particularly limited as long as it is a compound having one or more triple bonds in the molecule.
Specific examples of the compound having a triple bond include, for example, the following compounds.
1-Pentin, 2-Pentin, 1-Hexin, 2-Hexin, 3-Hexin, 1-Heptin, 2-Heptin, 3-Heptin, 1-Octin, 2-Octin, 3-Octin, 4-Octin, 1- Nonin, 2-nonin, 3-nonin, 4-nonin, 1-dodecin, 2-dodecin, 3-dodecin, 4-dodecin, 5-dodecin, phenylacetylene, 1-phenyl-1-propyne, 1-phenyl-2 -Propine, 1-phenyl-1-butyne, 4-phenyl-1-butyne, 4-phenyl-1-butyne, 1-phenyl-1-pentyne, 5-phenyl-1-pentyne, 1-phenyl-1-hexyne And hydrocarbon compounds such as 6-phenyl-1-hexyne, diphenylacetylene, 4-ethynyltoluene, dicyclohexylacetylene and the like;
２－プロピニルメチルカーボネート、２－プロピニルエチルカーボネート、２－プロピニルプロピルカーボネート、２－プロピニルブチルカーボネート、２－プロピニルフェニルカーボネート、２－プロピニルシクロヘキシルカーボネート、ジ－２－プロピニルカーボネート、１－メチル－２－プロピニルメチルカーボネート、１，１－ジメチル－２－プロピニルメチルカーボネート、２－ブチニルメチルカーボネート、３－ブチニルメチルカーボネート、２－ペンチニルメチルカーボネート、３－ペンチニルメチルカーボネート、４－ペンチニルメチルカーボネート等のモノカーボネート；２－ブチン－１，４－ジオール　ジメチルジカーボネート、２－ブチン－１，４－ジオール　ジエチルジカーボネート、２－ブチン－１，４－ジオール　ジプロピルジカーボネート、２－ブチン－１，４－ジオール　ジブチルジカーボネート、２－ブチン－１，４－ジオール　ジフェニルジカーボネート、２－ブチン－１，４－ジオール　ジシクロヘキシルジカーボネート等のジカーボネート； 2-propynyl methyl carbonate, 2-propynyl ethyl carbonate, 2-propynyl propyl carbonate, 2-propynyl butyl carbonate, 2-propynyl phenyl carbonate, 2-propynyl cyclohexyl carbonate, di-2-propynyl carbonate, 1-methyl-2-propynyl Methyl carbonate, 1,1-dimethyl-2-propynyl methyl carbonate, 2-butynyl methyl carbonate, 3-butynyl methyl carbonate, 2-pentynyl methyl carbonate, 3-pentynyl methyl carbonate, 4-pentynyl methyl carbonate, etc. Monocarbonates; 2-butyne-1,4-diol dimethyl dicarbonate, 2-butyne-1,4-diol diethyl dicarbonate, 2-butyne-1,4-dio Dipropyl dicarbonate, 2-butyne-1,4-diol dibutyl carbonate, 2-butyne-1,4-diol diphenyl carbonate, dicarbonate such as 2-butyne-1,4-diol and dicyclohexyl carbonate;
酢酸２－プロピニル、プロピオン酸２－プロピニル、酪酸２－プロピニル、安息香酸２－プロピニル、シクロヘキシルカルボン酸２－プロピニル、酢酸１，１－ジメチル－２－プロピニル、プロピオン酸１，１－ジメチル－２－プロピニル、酪酸１，１－ジメチル－２－プロピニル、安息香酸１，１－ジメチル－２－プロピニル、シクロヘキシルカルボン酸１，１－ジメチル－２－プロピニル、酢酸２－ブチニル、酢酸３－ブチニル、酢酸２－ペンチニル、酢酸３－ペンチニル、酢酸４－ペンチニル、アクリル酸メチル、アクリル酸エチル、アクリル酸プロピル、アクリル酸ビニル、アクリル酸２－プロペニル、アクリル酸２－ブテニル、アクリル酸３－ブテニル、メタクリル酸メチル、メタクリル酸エチル、メタクリル酸プロピル、メタクリル酸ビニル、メタクリル酸２－プロペニル、メタクリル酸２－ブテニル、メタクリル酸３－ブテニル、２－プロピン酸メチル、２－プロピン酸エチル、２－プロピン酸プロピル、２－プロピン酸ビニル、２－プロピン酸２－プロペニル、２－プロピン酸２－ブテニル、２－プロピン酸３－ブテニル、２－ブチン酸メチル、２－ブチン酸エチル、２－ブチン酸プロピル、２－ブチン酸ビニル、２－ブチン酸２－プロペニル、２－ブチン酸２－ブテニル、２－ブチン酸３－ブテニル、３－ブチン酸メチル、３－ブチン酸エチル、３－ブチン酸プロピル、３－ブチン酸ビニル、３－ブチン酸２－プロペニル、３－ブチン酸２－ブテニル、３－ブチン酸３－ブテニル、２－ペンチン酸メチル、２－ペンチン酸エチル、２－ペンチン酸プロピル、２－ペンチン酸ビニル、２－ペンチン酸２－プロペニル、２－ペンチン酸２－ブテニル、２－ペンチン酸３－ブテニル、３－ペンチン酸メチル、３－ペンチン酸エチル、３－ペンチン酸プロピル、３－ペンチン酸ビニル、３－ペンチン酸２－プロペニル、３－ペンチン酸２－ブテニル、３－ペンチン酸３－ブテニル、４－ペンチン酸メチル、４－ペンチン酸エチル、４－ペンチン酸プロピル、４－ペンチン酸ビニル、４－ペンチン酸２－プロペニル、４－ペンチン酸２－ブテニル、４－ペンチン酸３－ブテニル等のモノカルボン酸エステル、フマル酸エステル、トリメチル酢酸メチル、トリメチル酢酸エチル； 2-propynyl acetate, 2-propynyl propionate, 2-propynyl butyrate, 2-propynyl benzoate, 2-propynyl cyclohexylcarboxylate, 1,1-dimethyl-2-propynyl acetate, 1,1-dimethyl-2-propionic acid Propynyl, 1,1-dimethyl-2-propynyl butyrate, 1,1-dimethyl-2-propynyl benzoate, 1,1-dimethyl-2-propynyl cyclohexylcarboxylate, 2-butynyl acetate, 3-butynyl acetate, 2-acetic acid -Pentynyl, 3-pentynyl acetate, 4-pentynyl acetate, methyl acrylate, ethyl acrylate, propyl acrylate, vinyl acrylate, 2-propenyl acrylate, 2-butenyl acrylate, 3-butenyl acrylate, methyl methacrylate , Ethyl Methacrylate, Propyl Methacrylate, Methac Vinyl lactate, 2-propenyl methacrylate, 2-butenyl methacrylate, 3-butenyl methacrylate, methyl 2-propynoate, ethyl 2-propynoate, propyl 2-propynoate, vinyl 2-propynoate, 2-propynoic acid 2-propenyl, 2-butynyl 2-propynoate, 3-butenyl 2-propynoate, methyl 2-butyrate, ethyl 2-butyrate, propyl 2-butynoate, vinyl 2-butynoate, 2-butynoate Propenyl, 2-butenyl 2-butyrate, 3-butenyl 2-butyrate, methyl 3-butyrate, ethyl 3-butyrate, propyl 3-butynoate, vinyl 3-butynoate, 2-propenyl 3-butynate, 3-butyric acid 2-butenyl, 3-butynyl 3-butenyl, methyl 2-pentyrate, ethyl 2-pentyrate, propyl 2-pentyrate, 2- Vinyl benzoate, 2-propenyl 2-pentyrate, 2-butenyl 2-pentyrate, 3-butenyl 2-pentyrate, methyl 3-pentyrate, ethyl 3-pentyrate, propyl 3-pentynoate, 3-pentynoate Vinyl, 2-propenyl 3-pentyrate, 2-butenyl 3-pentyrate, 3-butenyl 3-pentyrate, methyl 4-pentyrate, ethyl 4-pentyrate, propyl 4-pentyrate, vinyl 4-pentynoate, Monocarboxylic acid esters such as 4-propynoic acid 2-propenyl, 4-butyric acid 2-butenyl, 4-butyric acid 3-butenyl and the like, fumaric acid esters, methyl trimethylacetate, ethyl trimethylacetate;
２－ブチン－１，４－ジオール　ジアセテート、２－ブチン－１，４－ジオール　ジプロピオネート、２－ブチン－１，４－ジオール　ジブチレート、２－ブチン－１，４－ジオール　ジベンゾエート、２－ブチン－１，４－ジオール　ジシクロヘキサンカルボキシレート、ヘキサヒドロベンゾ［１，３，２］ジオキサチオラン－２－オキシド（１，２－シクロヘキサンジオール、２，２－ジオキシド－１，２－オキサチオラン－４－イルアセテート、２，２－ジオキシド－１，２－オキサチオラン－４－イルアセテート等のジカルボン酸エステル； 2-butyne-1,4-diol diacetate, 2-butyne-1,4-diol dipropionate, 2-butyne-1,4-diol dibutyrate, 2-butyne-1,4-diol dibenzoate, 2-butyne -1,4-diol dicyclohexanecarboxylate, hexahydrobenzo [1,3,2] dioxathiolane-2-oxide (1,2-cyclohexanediol, 2,2-dioxide-1,2-oxathiolan-4-yl acetate , Dicarboxylic acid esters such as 2,2-dioxide-1,2-oxathiolan-4-yl acetate;
シュウ酸メチル　２－プロピニル、シュウ酸エチル　２－プロピニル、シュウ酸プロピル　２－プロピニル、シュウ酸２－プロピニル　ビニル、シュウ酸アリル　２－プロピニル、シュウ酸ジ－２－プロピニル、シュウ酸２－ブチニル　メチル、シュウ酸２－ブチニル　エチル、シュウ酸２－ブチニルプロピル、シュウ酸２－ブチニル　ビニル、シュウ酸アリル　２－ブチニル、シュウ酸　ジ－２－ブチニル、シュウ酸３－ブチニル　メチル、シュウ酸３－ブチニル　エチル、シュウ酸３－ブチニルプロピル、シュウ酸３－ブチニル　ビニル、シュウ酸アリル　３－ブチニル、シュウ酸ジ－３－ブチニル等のシュウ酸ジエステル； Methyl oxalate 2-propynyl, ethyl oxalate 2-propynyl, propyl oxalate 2-propynyl, oxalate 2-propynyl vinyl, allyl oxalate 2-propynyl oxalate, di-2-propynyl oxalate, 2-butynyl methyl oxalate, Ethyl 2-butynyl oxalate, 2-butynyl propyl oxalate, vinyl 2-butynyl oxalate, allyl 2-butynyl oxalate, di-2-butynyl oxalate, 3-butynyl methyl oxalate, 3-butynyl ethyl oxalate Oxalic acid diesters such as 3-butynylpropyl oxalate, 3-butynyl vinyl oxalate, allyl 3-butynyl oxalate, di-3-butynyl oxalate;
メチル（２－プロピニル）（ビニル）ホスフィンオキシド、ジビニル（２－プロピニル）ホスフィンオキシド、ジ（２－プロピニル）（ビニル）ホスフィンオキシド、ジ（２－プロペニル）２（－プロピニル）ホスフィンオキシド、ジ（２－プロピニル）（２－プロペニル）ホスフィンオキシド、ジ（３－ブテニル）（２－プロピニル）ホスフィンオキシド、及びジ（２－プロピニル）（３－ブテニル）ホスフィンオキシド等のホスフィンオキシド； Methyl (2-propynyl) (vinyl) phosphine oxide, divinyl (2- propynyl) phosphine oxide, di (2- propynyl) (vinyl) phosphine oxide, di (2- propenyl) 2 (-propynyl) phosphine oxide, di (2 Phosphine oxides such as propynyl) (2-propenyl) phosphine oxide, di (3-butenyl) (2-propynyl) phosphine oxide, and di (2-propynyl) (3-butenyl) phosphine oxide;
メチル（２－プロペニル）ホスフィン酸２－プロピニル、２－ブテニル（メチル）ホスフィン酸２－プロピニル、ジ（２－プロペニル）ホスフィン酸２－プロピニル、ジ（３－ブテニル）ホスフィン酸２－プロピニル、メチル（２－プロペニル）ホスフィン酸１，１－ジメチル－２－プロピニル、２－ブテニル（メチル）ホスフィン酸１，１－ジメチル－２－プロピニル、ジ（２－プロペニル）ホスフィン酸１，１－ジメチル－２－プロピニル、及びジ（３－ブテニル）ホスフィン酸１，１－ジメチル－２－プロピニル、メチル（２－プロピニル）ホスフィン酸２－プロペニル、メチル（２－プロピニル）ホスフィン酸３－ブテニル、ジ（２－プロピニル）ホスフィン酸２－プロペニル、ジ（２－プロピニル）ホスフィン酸３－ブテニル、２－プロピニル（２－プロペニル）ホスフィン酸２－プロペニル、及び２－プロピニル（２－プロペニル）ホスフィン酸３－ブテニル等のホスフィン酸エステル； 2-propynyl methyl (2-propenyl) phosphinate, 2-propynyl 2-butenyl (methyl) phosphinate, 2-propynyl di (2-propenyl) phosphinate, 2-propynyl di (3-butenyl) phosphinate, methyl (2-propenyl) 2-propenyl) phosphinic acid 1,1-dimethyl-2-propynyl, 2-butenyl (methyl) phosphinic acid 1,1-dimethyl-2-propynyl, di (2-propenyl) phosphinic acid 1,1-dimethyl-2- Propynyl and 1,1-dimethyl-2-propynyl di (3-butenyl) phosphinic acid, 2-propenyl methyl (2-propynyl) phosphinic acid, 3-butenyl methyl (2-propynyl) phosphinic acid, di (2-propynyl) ) 2-propenyl phosphinate, 3-butenyl di (2-propynyl) phosphinate, 2 Propynyl (2-propenyl) phosphinic acid 2-propenyl, and 2-propynyl (2-propenyl) phosphinic acid 3-phosphinic acid esters butenyl;
２－プロペニルホスホン酸メチル　２－プロピニル、２－ブテニルホスホン酸メチル（２－プロピニル）、２－プロペニルホスホン酸（２－プロピニル）（２－プロペニル）、３－ブテニルホスホン酸（３－ブテニル）（２－プロピニル）、２－プロペニルホスホン酸（１，１－ジメチル－２－プロピニル）（メチル）、２－ブテニルホスホン酸（１，１－ジメチル－２－プロピニル）（メチル）、２－プロペニルホスホン酸（１，１－ジメチル－２－プロピニル）（２－プロペニル）、及び３－ブテニルホスホン酸（３－ブテニル）（１，１－ジメチル－２－プロピニル）、メチルホスホン酸（２－プロピニル）（２－プロペニル）、メチルホスホン酸（３－ブテニル）（２－プロピニル）、メチルホスホン酸（１，１－ジメチル－２－プロピニル）（２－プロペニル）、メチルホスホン酸（３－ブテニル）（１，１－ジメチル－２－プロピニル）、エチルホスホン酸（２－プロピニル）（２－プロペニル）、エチルホスホン酸（３－ブテニル）（２－プロピニル）、エチルホスホン酸（１，１－ジメチル－２－プロピニル）（２－プロペニル）、及びエチルホスホン酸（３－ブテニル）（１，１－ジメチル－２－プロピニル）等のホスホン酸エステル； 2-propenyl phosphonate methyl 2-propynyl, methyl 2-butenyl phosphonate (2-propynyl), 2-propenyl phosphonic acid (2-propynyl) (2-propenyl), 3-butenyl phosphonic acid (3-butenyl) (2-propynyl) ), 2-propenyl phosphonic acid (1,1-dimethyl-2-propynyl) (methyl), 2-butenyl phosphonic acid (1,1-dimethyl-2-propynyl) (methyl), 2-propenyl phosphonic acid (1,1 -Dimethyl-2-propynyl) (2-propenyl), and 3-butenylphosphonic acid (3-butenyl) (1,1-dimethyl-2-propynyl), methylphosphonic acid (2-propynyl) (2-propenyl), methylphosphonic acid (3-butenyl) (2-propynyl), methylphosphonic acid (1,1-dimethyl-2-propane) Pinyl) (2-propenyl), methylphosphonic acid (3-butenyl) (1,1-dimethyl-2-propynyl), ethylphosphonic acid (2-propynyl) (2-propenyl), ethylphosphonic acid (3-butenyl) ( Phosphonic esters such as 2-propynyl), ethylphosphonic acid (1,1-dimethyl-2-propynyl) (2-propenyl), and ethylphosphonic acid (3-butenyl) (1,1-dimethyl-2-propynyl) ;
リン酸（メチル）（２－プロペニル）（２－プロピニル）、リン酸（エチル）（２－プロペニル）（２－プロピニル）、リン酸（２－ブテニル）（メチル）（２－プロピニル）、リン酸（２－ブテニル）（エチル）（２－プロピニル）、リン酸（１，１－ジメチル－２－プロピニル）（メチル）（２－プロペニル）、リン酸（１，１－ジメチル－２－プロピニル）（エチル）（２－プロペニル）、リン酸（２－ブテニル）（１，１－ジメチル－２－プロピニル）（メチル）、及びリン酸（２－ブテニル）（エチル）（１，１－ジメチル－２－プロピニル）等のリン酸エステル。 Phosphoric acid (methyl) (2-propenyl) (2-propynyl), phosphoric acid (ethyl) (2-propenyl) (2-propynyl), phosphoric acid (2-butenyl) (methyl) (methyl) (2-propynyl), phosphoric acid (2-butenyl) (ethyl) (2-propynyl), phosphoric acid (1,1-dimethyl-2-propynyl) (methyl) (2-propenyl), phosphoric acid (1,1-dimethyl-2-propynyl) ( Ethyl) (2-propenyl), phosphoric acid (2-butenyl) (1,1-dimethyl-2-propynyl) (methyl), and phosphoric acid (2-butenyl) (ethyl) (1,1-dimethyl-2-) Phosphate esters such as propynyl).
これらのうち、アルキニルオキシ基を有する化合物は、電解液中でより安定に負極被膜を形成するため好ましい。 Among these, compounds having an alkynyloxy group are preferable because they form a negative electrode film more stably in the electrolytic solution.
更に、２－プロピニルメチルカーボネート、ジ－２－プロピニルカーボネート、２－ブチン－１，４－ジオール　ジメチルジカーボネート、酢酸２－プロピニル、２－ブチン－１，４－ジオール　ジアセテート、シュウ酸メチル　２－プロピニル、シュウ酸ジ－２－プロピニル等の化合物が保存特性向上の点から特に好ましい。 Furthermore, 2-propynyl methyl carbonate, di-2-propynyl carbonate, 2-butyne-1,4-diol dimethyl dicarbonate, 2-propynyl acetate, 2-butyne-1,4-diol diacetate, methyl oxalate 2- Compounds such as propynyl, di-2-propynyl oxalate and the like are particularly preferable from the viewpoint of improving the storage characteristics.
上記三重結合を有する化合物は、１種を単独で用いてもよく、２種以上を任意の組み合わせ及び比率で併用してもよい。本発明の電解液全体に対する三重結合を有する化合物の配合量に制限は無く、本発明の効果を著しく損なわない限り任意であるが、本発明の電解液に対して、通常０．０１質量％以上、好ましくは０．０５質量％以上、より好ましくは０．１質量％以上、また、通常５質量％以下、好ましくは３質量％以下、より好ましくは１質量％以下の濃度で含有させる。上記範囲を満たした場合は、出力特性、負荷特性、サイクル特性、高温保存特性等の効果がより向上する。 The compounds having a triple bond may be used alone or in any combination of two or more in any proportion. The compounding amount of the compound having a triple bond with respect to the entire electrolytic solution of the present invention is not limited, and is optional unless the effects of the present invention are significantly impaired, but generally 0.01% by mass or more with respect to the electrolytic solution of the present invention Preferably, it is contained at a concentration of 0.05% by mass or more, more preferably 0.1% by mass or more, and usually 5% by mass or less, preferably 3% by mass or less, more preferably 1% by mass or less. When the above range is satisfied, effects such as output characteristics, load characteristics, cycle characteristics, high temperature storage characteristics and the like are further improved.
本発明の電解液においては、電解液を用いた電気化学デバイスが過充電等の状態になった際に電池の破裂・発火を効果的に抑制するために、過充電防止剤を用いることができる。 In the electrolytic solution of the present invention, an overcharge preventing agent can be used to effectively suppress the battery from bursting / ignition when the electrochemical device using the electrolytic solution becomes overcharged or the like. .
過充電防止剤としては、ビフェニル、ｏ－ターフェニル、ｍ－ターフェニル、ｐ－ターフェニル等の無置換又はアルキル基で置換されたターフェニル誘導体、無置換又はアルキル基で置換されたターフェニル誘導体の部分水素化物、シクロヘキシルベンゼン、ｔ－ブチルベンゼン、ｔ－アミルベンゼン、ジフェニルエーテル、ジベンゾフラン、ジフェニルシクロヘキサン、１，１，３－トリメチル－３－フェニルインダン、シクロペンチルベンゼン、シクロヘキシルベンゼン、クメン、１，３－ジイソプロピルベンゼン、１，４－ジイソプロピルベンゼン、ｔ－ブチルベンゼン、ｔ－アミルベンゼン、ｔ－ヘキシルベンゼン、アニソール等の芳香族化合物；２－フルオロビフェニル、４－フルオロビフェニル、ｏ－シクロヘキシルフルオロベンゼン、ｐ－シクロヘキシルフルオロベンゼン、ｏ－シクロヘキシルフルオロベンゼン、ｐ－シクロヘキシルフルオロベンゼンフルオロベンゼン、フルオロトルエン、ベンゾトリフルオリド等の上記芳香族化合物の部分フッ素化物；２，４－ジフルオロアニソール、２，５－ジフルオロアニソール、１，６－ジフルオロアニソール、２，６－ジフルオロアニソール、３，５－ジフルオロアニソール等の含フッ素アニソール化合物；３－プロピルフェニルアセテート、２－エチルフェニルアセテート、ベンジルフェニルアセテート、メチルフェニルアセテート、ベンジルアセテート、フェネチルフェニルアセテート等の芳香族アセテート類；ジフェニルカーボネート、メチルフェニルカーボネート等の芳香族カーボネート類；トルエン、キシレン等のトルエン誘導体；２－メチルビフェニル、３－メチルビフェニル、４－メチルビフェニル、ｏ－シクロヘキシルビフェニル等の無置換又はアルキル基で置換されたビフェニル誘導体等が挙げられる。中でも、ビフェニル、アルキルビフェニル、ターフェニル、ターフェニルの部分水素化体、シクロヘキシルベンゼン、ｔ－ブチルベンゼン、ｔ－アミルベンゼン、ジフェニルエーテル、ジベンゾフラン等の芳香族化合物、ジフェニルシクロヘキサン、１，１，３－トリメチル－３－フェニルインダン、３－プロピルフェニルアセテート、２－エチルフェニルアセテート、ベンジルフェニルアセテート、メチルフェニルアセテート、ベンジルアセテート、ジフェニルカーボネート、メチルフェニルカーボネート等が好ましい。これらは１種を単独で用いても、２種以上を併用してもよい。２種以上併用する場合は、特に、シクロヘキシルベンゼンとｔ－ブチルベンゼン又はｔ－アミルベンゼンとの組み合わせ、ビフェニル、アルキルビフェニル、ターフェニル、ターフェニルの部分水素化体、シクロヘキシルベンゼン、ｔ－ブチルベンゼン、ｔ－アミルベンゼン等の酸素を含有しない芳香族化合物から選ばれる少なくとも１種と、ジフェニルエーテル、ジベンゾフラン等の含酸素芳香族化合物から選ばれる少なくとも１種を併用するのが過充電防止特性と高温保存特性のバランスの点から好ましい。 As the overcharge inhibiting agent, a non-substituted or alkyl-substituted terphenyl derivative such as biphenyl, o-terphenyl, m-terphenyl, p-terphenyl, etc., a non-substituted or alkyl-substituted terphenyl derivative Partial hydrides of cyclohexylbenzene, t-butylbenzene, t-amylbenzene, diphenylether, dibenzofuran, diphenylcyclohexane, 1,1,3-trimethyl-3-phenylindane, cyclopentylbenzene, cyclohexylbenzene, cumene, 1,3- Aromatic compounds such as diisopropylbenzene, 1,4-diisopropylbenzene, t-butylbenzene, t-amylbenzene, t-hexylbenzene, anisole; 2-fluorobiphenyl, 4-fluorobiphenyl, o-cyclohexylfluorobenzene Partially fluorinated compounds of the above aromatic compounds such as benzene, p-cyclohexyl fluorobenzene, o-cyclohexyl fluorobenzene, p-cyclohexyl fluorobenzene fluorobenzene, fluorotoluene, benzotrifluoride, etc .; 2,4-difluoroanisole, 2,5- Fluorine-containing anisole compounds such as difluoroanisole, 1,6-difluoroanisole, 2,6-difluoroanisole, 3,5-difluoroanisole; 3-propylphenyl acetate, 2-ethylphenyl acetate, benzylphenyl acetate, methylphenyl acetate, Aromatic acetates such as benzyl acetate and phenethyl phenyl acetate; Aromatic carbonates such as diphenyl carbonate and methyl phenyl carbonate; Toluene and xylene Toluene derivatives and the like; 2-methylbiphenyl, 3-methylbiphenyl, 4-methyl biphenyl, biphenyl derivatives which are unsubstituted or substituted alkyl group such as o- cyclohexyl biphenyl. Among them, aromatic compounds such as biphenyl, alkylbiphenyl, terphenyl, partially hydrogenated terphenyl, cyclohexylbenzene, t-butylbenzene, t-amylbenzene, diphenylether, dibenzofuran, etc., diphenylcyclohexane, 1,1,3-trimethyl -3-phenylindane, 3-propylphenylacetate, 2-ethylphenylacetate, benzylphenylacetate, methylphenylacetate, benzylacetate, diphenyl carbonate, methylphenyl carbonate and the like are preferable. These may be used alone or in combination of two or more. When two or more kinds are used in combination, in particular, a combination of cyclohexylbenzene and t-butylbenzene or t-amylbenzene, biphenyl, alkylbiphenyl, terphenyl, a partially hydrogenated terphenyl, cyclohexylbenzene, t-butylbenzene, The combined use of at least one selected from oxygen-free aromatic compounds such as t-amyl benzene and at least one selected from oxygen-containing aromatic compounds such as diphenyl ether and dibenzofuran is an overcharge preventing property and high temperature storage characteristics It is preferable from the point of balance of
本発明に使用する電解液には、カルボン酸無水物（但し、化合物（２）を除く）を用いてもよい。下記一般式（６）で表される化合物が好ましい。カルボン酸無水物の製造方法は、特に制限されず、公知の方法を任意に選択して製造することが可能である。 A carboxylic acid anhydride (except for the compound (2)) may be used in the electrolytic solution used in the present invention. The compound represented by following General formula (6) is preferable. The method for producing the carboxylic acid anhydride is not particularly limited, and any known method can be selected for production.
Figure JPOXMLDOC01-appb-C000079
 （一般式（６）中、Ｒ６１、Ｒ６２はそれぞれ独立に、置換基を有していてもよい、炭素数１以上１５以下の炭化水素基を表す。）
Figure JPOXMLDOC01-appb-C000079
 (In the general formula (6), each of R 61 and R 62 independently represents a hydrocarbon group having 1 to 15 carbon atoms which may have a substituent.)
Ｒ６１、Ｒ６２は、一価の炭化水素基であれば、その種類は特に制限されない。例えば、脂肪族炭化水素基であっても芳香族炭化水素基であってもよく、脂肪族炭化水素基と芳香族炭化水素基とが結合したものであってもよい。脂肪族炭化水素基は、飽和炭化水素基であってもよく、不飽和結合（炭素－炭素二重結合又は炭素－炭素三重結合）を含んでいてもよい。また、脂肪族炭化水素基は、鎖状であっても環状であってもよく、鎖状の場合は、直鎖状であっても分岐鎖状であってもよい。更には、鎖状と環状とが結合したものであってもよい。なお、Ｒ６１及びＲ６２は互いに同一であってもよく、異なっていてもよい。 The type of R 61 and R 62 is not particularly limited as long as it is a monovalent hydrocarbon group. For example, it may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, or it may be a combination of an aliphatic hydrocarbon group and an aromatic hydrocarbon group. The aliphatic hydrocarbon group may be a saturated hydrocarbon group and may contain an unsaturated bond (carbon-carbon double bond or carbon-carbon triple bond). The aliphatic hydrocarbon group may be linear or cyclic, and in the case of linear, it may be linear or branched. Furthermore, the chain and cyclic groups may be combined. R 61 and R 62 may be identical to or different from each other.
また、Ｒ６１、Ｒ６２の炭化水素基が置換基を有する場合、その置換基の種類は、本発明の趣旨に反するものでない限り特に制限されないが、例としてはフッ素原子、塩素原子、臭素原子、ヨウ素原子等のハロゲン原子が挙げられ、好ましくはフッ素原子である。又はロゲン原子以外の置換基として、エステル基、シアノ基、カルボニル基、エーテル基等の官能基を有する置換基等も挙げられ、好ましくはシアノ基、カルボニル基である。Ｒ６１、Ｒ６２の炭化水素基は、これらの置換基を一つのみ有していてもよく、二つ以上有していてもよい。二つ以上の置換基を有する場合、それらの置換基は同じであってもよく、互いに異なっていてもよい。 Further, when the hydrocarbon group of R 61 and R 62 has a substituent, the type of the substituent is not particularly limited unless it is contrary to the spirit of the present invention, and examples thereof include a fluorine atom, a chlorine atom and a bromine atom And a halogen atom such as iodine atom, preferably a fluorine atom. Alternatively, as a substituent other than a rogen atom, a substituent having a functional group such as an ester group, a cyano group, a carbonyl group, an ether group and the like can be mentioned, with preference given to a cyano group and a carbonyl group. The hydrocarbon group of R 61 and R 62 may have only one of these substituents, or may have two or more of these substituents. When they have two or more substituents, those substituents may be the same or may be different from each other.
Ｒ６１、Ｒ６２の各々の炭化水素基の炭素数は、通常１以上であり、また通常１５以下、好ましくは１２以下、より好ましくは１０以下、更に好ましくは９以下である。Ｒ１とＲ２とが互いに結合して二価の炭化水素基を形成している場合は、その二価の炭化水素基の炭素数が、通常１以上であり、また通常１５以下、好ましくは１３以下、より好ましくは１０以下、更に好ましくは８以下である。尚、Ｒ６１、Ｒ６２の炭化水素基が炭素原子を含有する置換基を有する場合は、その置換基も含めたＲ６１、Ｒ６２全体の炭素数が上記範囲を満たしていることが好ましい。 The carbon number of each of the hydrocarbon groups of R 61 and R 62 is usually 1 or more, and usually 15 or less, preferably 12 or less, more preferably 10 or less, still more preferably 9 or less. When R 1 and R 2 are bonded to each other to form a bivalent hydrocarbon group, the carbon number of the bivalent hydrocarbon group is usually 1 or more, and usually 15 or less, preferably It is 13 or less, more preferably 10 or less, still more preferably 8 or less. When the hydrocarbon group of R 61 and R 62 has a substituent containing a carbon atom, it is preferable that the total number of carbon atoms of R 61 and R 62 including the substituent satisfy the above range.
次いで、上記一般式（６）で表わされる酸無水物の具体例について説明する。なお、以下の例示において「類縁体」とは、例示される酸無水物の構造の一部を、本発明の趣旨に反しない範囲で、別の構造に置き換えることにより得られる酸無水物を指すもので、例えば複数の酸無水物からなる二量体、三量体及び四量体等、又は、置換基の炭素数が同じではあるが分岐鎖を有する等構造異性のもの、置換基が酸無水物に結合する部位が異なるもの等が挙げられる。 Next, specific examples of the acid anhydride represented by the above general formula (6) will be described. In the following examples, “analog” refers to an acid anhydride obtained by replacing a part of the structure of the exemplified acid anhydride with another structure without departing from the spirit of the present invention. For example, dimers, trimers and tetramers of multiple acid anhydrides, etc., or equistructural isomers having the same carbon number of substituents but having branched chains, and the substituent is an acid Those having different sites of binding to an anhydride and the like can be mentioned.
まず、Ｒ６１、Ｒ６２が同一である酸無水物の具体例を以下に挙げる。 First, specific examples of acid anhydrides in which R 61 and R 62 are the same are listed below.
Ｒ６１、Ｒ６２が鎖状アルキル基である酸無水物の具体例としては、無水酢酸、プロピオン酸無水物、ブタン酸無水物、２－メチルプロピオン酸無水物、２，２－ジメチルプロピオン酸無水物、２－メチルブタン酸無水物、３－メチルブタン酸無水物、２，２－ジメチルブタン酸無水物、２，３－ジメチルブタン酸無水物、３，３－ジメチルブタン酸無水物、２，２，３－トリメチルブタン酸無水物、２，３，３－トリメチルブタン酸無水物、２，２，３，３－テトラメチルブタン酸無水物、２－エチルブタン酸無水物等、及びそれらの類縁体等が挙げられる。 Specific examples of the acid anhydride in which R 61 and R 62 are a linear alkyl group include acetic anhydride, propionic anhydride, butanoic acid anhydride, 2-methylpropionic acid anhydride, and 2,2-dimethylpropionic acid anhydride , 2-methylbutanoic anhydride, 3-methylbutanoic anhydride, 2,2-dimethylbutanoic anhydride, 2,3-dimethylbutanoic anhydride, 3,3-dimethylbutanoic anhydride, 2,2, 3-trimethylbutanoic acid anhydride, 2,3,3-trimethylbutanoic acid anhydride, 2,2,3,3-tetramethylbutanoic acid anhydride, 2-ethylbutanoic acid anhydride, etc., and analogs thereof It can be mentioned.
Ｒ６１、Ｒ６２が環状アルキル基である酸無水物の具体例としては、シクロプロパンカルボン酸無水物、シクロペンタンカルボン酸無水物、シクロヘキサンカルボン酸無水物等、及びそれらの類縁体等が挙げられる。 Specific examples of acid anhydrides wherein R 61 and R 62 are cyclic alkyl groups include cyclopropane carboxylic acid anhydride, cyclopentane carboxylic acid anhydride, cyclohexane carboxylic acid anhydride, etc., and analogs thereof, etc. .
Ｒ６１、Ｒ６２がアルケニル基である酸無水物の具体例としては、アクリル酸無水物、２－メチルアクリル酸無水物、３－メチルアクリル酸無水物、２，３－ジメチルアクリル酸無水物、３，３－ジメチルアクリル酸無水物、２，３，３－トリメチルアクリル酸無水物、２－フェニルアクリル酸無水物、３－フェニルアクリル酸無水物、２，３－ジフェニルアクリル酸無水物、３，３－ジフェニルアクリル酸無水物、３－ブテン酸無水物、２－メチル－３－ブテン酸無水物、２，２－ジメチル－３－ブテン酸無水物、３－メチル－３－テン酸無水物、２－メチル－３－メチル－３－ブテン酸無水物、２，２－ジメチル－３－メチル－３－ブテン酸無水物、３－ペンテン酸無水物、４－ペンテン酸無水物、２－シクロペンテンカルボン酸無水物、３－シクロペンテンカルボン酸無水物、４－シクロペンテンカルボン酸無水物等、及びそれらの類縁体等が挙げられる。 Specific examples of the acid anhydride wherein R 61 and R 62 are an alkenyl group include acrylic acid anhydride, 2-methyl acrylic acid anhydride, 3-methyl acrylic acid anhydride, 2,3-dimethyl acrylic acid anhydride, 3,3-Dimethylacrylic anhydride, 2,3,3-trimethylacrylic anhydride, 2-phenylacrylic anhydride, 3-phenylacrylic anhydride, 2,3-diphenylacrylic anhydride, 3, 3-diphenylacrylic anhydride, 3-butenoic anhydride, 2-methyl-3-butenoic anhydride, 2,2-dimethyl-3-butenoic anhydride, 3-methyl-3-tenoic anhydride, 2-Methyl-3-methyl-3-butenoic anhydride, 2,2-dimethyl-3-methyl-3-butenoic anhydride, 3-pentenoic anhydride, 4-pentenoic anhydride, 2-cyclopentene carboxylic acid Acid anhydride , 3-cyclopentene carboxylic acid anhydride, 4-cyclopentenecarboxylic acid anhydride and the like, and analogs of these compounds.
Ｒ６１、Ｒ６２がアルキニル基である酸無水物の具体例としては、プロピン酸無水物、３－フェニルプロピン酸無水物、２－ブチン酸無水物、２－ペンチン酸無水物、３－ブチン酸無水物、３－ペンチン酸無水物、４－ペンチン酸無水物等、及びそれらの類縁体等が挙げられる。 Specific examples of the acid anhydride wherein R 61 and R 62 are an alkynyl group include propynic acid anhydride, 3-phenylpropynic acid anhydride, 2-butyric acid anhydride, 2-pentynic acid anhydride, 3-butyric acid Anhydrides, 3-pentynic acid anhydride, 4-pentynic acid anhydride and the like, and analogs thereof and the like can be mentioned.
Ｒ６１、Ｒ６２がアリール基である酸無水物の具体例としては、安息香酸無水物、４－メチル安息香酸無水物、４－エチル安息香酸無水物、４－ｔｅｒｔ－ブチル安息香酸無水物、２－メチル安息香酸無水物、２，４，６－トリメチル安息香酸無水物、１－ナフタレンカルボン酸無水物、２－ナフタレンカルボン酸無水物等、及びそれらの類縁体等が挙げられる。 Specific examples of the acid anhydride wherein R 61 and R 62 are aryl groups include benzoic acid anhydride, 4-methylbenzoic acid anhydride, 4-ethylbenzoic acid anhydride, 4-tert-butylbenzoic acid anhydride, Examples thereof include 2-methylbenzoic acid anhydride, 2,4,6-trimethylbenzoic acid anhydride, 1-naphthalenecarboxylic acid anhydride, 2-naphthalenecarboxylic acid anhydride and the like, and analogs thereof.
また、Ｒ６１、Ｒ６２がハロゲン原子で置換された酸無水物の例として、主にフッ素原子で置換された酸無水物の例を以下に挙げるが、これらのフッ素原子の一部又は全部を塩素原子、臭素原子、ヨウ素原子に置換して得られる酸無水物も、例示化合物に含まれるものとする。 As examples of the acid anhydride R 61, R 62 are substituted with halogen atoms, mainly cited example has been anhydride substituted with a fluorine atom are set forth below, some or all of these fluorine atoms An acid anhydride obtained by substitution to a chlorine atom, a bromine atom or an iodine atom is also included in the exemplified compounds.
Ｒ６１、Ｒ６２がハロゲン原子で置換された鎖状アルキル基である酸無水物の例としては、フルオロ酢酸無水物、ジフルオロ酢酸無水物、トリフルオロ酢酸無水物、２－フルオロプロピオン酸無水物、２，２－ジフルオロプロピオン酸無水物、２，３－ジフルオロプロピオン酸無水物、２，２，３－トリフルオロプロピオン酸無水物、２，３，３－トリフルオロプロピオン酸無水物、２，２，３，３－テトラプロピオン酸無水物、２，３，３，３－テトラプロピオン酸無水物、３－フルオロプロピオン酸無水物、３，３－ジフルオロプロピオン酸無水物、３，３，３－トリフルオロプロピオン酸無水物、パーフルオロプロピオン酸無水物等、及びそれらの類縁体等が挙げられる。 Examples of acid anhydrides in which R 61 and R 62 are a linear alkyl group substituted with a halogen atom include fluoroacetic acid anhydride, difluoroacetic acid anhydride, trifluoroacetic acid anhydride, 2-fluoropropionic acid anhydride, 2,2-difluoropropionic anhydride, 2,3-difluoropropionic anhydride, 2,2,3-trifluoropropionic anhydride, 2,3,3-trifluoropropionic anhydride, 2,2,3, 3,3-tetrapropionic anhydride, 2,3,3,3-tetrapropionic anhydride, 3-fluoropropionic anhydride, 3,3-difluoropropionic anhydride, 3,3,3-trifluoro Examples thereof include propionic acid anhydride, perfluoropropionic acid anhydride, and the like, and analogs thereof.
Ｒ６１、Ｒ６２がハロゲン原子で置換された環状アルキル基である酸無水物の例としては、２－フルオロシクロペンタンカルボン酸無水物、３－フルオロシクロペンタンカルボン酸無水物、４－フルオロシクロペンタンカルボン酸無水物等、及びそれらの類縁体等が挙げられる。 2-fluorocyclopentanecarboxylic acid anhydride, 3-fluorocyclopentanecarboxylic acid anhydride, 4-fluorocyclopentane as an example of the acid anhydride which is a cyclic alkyl group in which R 61 and R 62 are substituted by a halogen atom Examples thereof include carboxylic acid anhydrides and the like and analogs thereof.
Ｒ６１、Ｒ６２がハロゲン原子で置換されたアルケニル基である酸無水物の例としては、２－フルオロアクリル酸無水物、３－フルオロアクリル酸無水物、２，３－ジフルオロアクリル酸無水物、３，３－ジフルオロアクリル酸無水物、２，３，３－トリフルオロアクリル酸無水物、２－（トリフルオロメチル）アクリル酸無水物、３－（トリフルオロメチル）アクリル酸無水物、２，３－ビス（トリフルオロメチル）アクリル酸無水物、２，３，３－トリス（トリフルオロメチル）アクリル酸無水物、２－（４－フルオロフェニル）アクリル酸無水物、３－（４－フルオロフェニル）アクリル酸無水物、２，３－ビス（４－フルオロフェニル）アクリル酸無水物、３，３－ビス（４－フルオロフェニル）アクリル酸無水物、２－フルオロ－３－ブテン酸無水物、２，２－ジフルオロ－３－ブテン酸無水物、３－フルオロ－２－ブテン酸無水物、４－フルオロ－３－ブテン酸無水物、３，４－ジフルオロ－３－ブテン酸無水物、３，３，４－トリフルオロ－３－ブテン酸無水物等、及びそれらの類縁体等が挙げられる。 Examples of the acid anhydride which is an alkenyl group in which R 61 and R 62 are substituted by a halogen atom include 2-fluoroacrylic anhydride, 3-fluoroacrylic anhydride, 2,3-difluoroacrylic anhydride, 3,3-Difluoroacrylic anhydride, 2,3,3-trifluoroacrylic anhydride, 2- (trifluoromethyl) acrylic anhydride, 3- (trifluoromethyl) acrylic anhydride, 2,3 -Bis (trifluoromethyl) acrylic anhydride, 2,3,3-tris (trifluoromethyl) acrylic anhydride, 2- (4-fluorophenyl) acrylic anhydride, 3- (4-fluorophenyl) Acrylic anhydride, 2,3-bis (4-fluorophenyl) acrylic anhydride, 3,3-bis (4-fluorophenyl) acrylic anhydride, 2-fluoro 3-butenoic anhydride, 2,2-difluoro-3-butenoic anhydride, 3-fluoro-2-butenoic anhydride, 4-fluoro-3-butenoic anhydride, 3,4-difluoro-3-anhydride Examples thereof include butene acid anhydride, 3,3,4-trifluoro-3-butenoic acid anhydride and the like, and analogs thereof.
Ｒ６１、Ｒ６２がハロゲン原子で置換されたアルキニル基である酸無水物の例としては、３－フルオロ－２－プロピン酸無水物、３－（４－フルオロフェニル）－２－プロピン酸無水物、３－（２，３，４，５，６－ペンタフルオロフェニル）－２－プロピン酸無水物、４－フルオロ－２－ブチン酸無水物、４，４－ジフルオロ－２－ブチン酸無水物、４，４，４－トリフルオロ－２－ブチン酸無水物等、及びそれらの類縁体等が挙げられる。 As an example of the acid anhydride which is an alkynyl group in which R 61 and R 62 are substituted by a halogen atom, 3-fluoro-2-propanoic acid anhydride, 3- (4-fluorophenyl) -2-propynic acid anhydride , 3- (2,3,4,5,6-pentafluorophenyl) -2-propanoic acid anhydride, 4-fluoro-2-butyric acid anhydride, 4,4-difluoro-2-butyric acid anhydride, And 4,4,4-trifluoro-2-butyric anhydride and the like, and analogs thereof.
Ｒ６１、Ｒ６２がハロゲン原子で置換されたアリール基である酸無水物の例としては、４－フルオロ安息香酸無水物、２，３，４，５，６－ペンタフルオロ安息香酸無水物、４－トリフルオロメチル安息香酸無水物等、及びそれらの類縁体等が挙げられる。 Examples of the acid anhydride which is an aryl group in which R 61 and R 62 are substituted by a halogen atom include 4-fluorobenzoic acid anhydride, 2,3,4,5,6-pentafluorobenzoic acid anhydride, 4 And-trifluoromethylbenzoic anhydride and the like, and analogs thereof and the like.
Ｒ６１、Ｒ６２がエステル、ニトリル、ケトン、エーテル等の官能基を有する置換基を有している酸無水物の例としては、メトキシギ酸無水物、エトキシギ酸無水物、メチルシュウ酸無水物、エチルシュウ酸無水物、２－シアノ酢酸無水物、２－オキソプロピオン酸無水物、３－オキソブタン酸無水物、４－アセチル安息香酸無水物、メトキシ酢酸無水物、４－メトキシ安息香酸無水物等、及びそれらの類縁体等が挙げられる。 Examples of the acid anhydride having a substituent having a functional group such as ester, nitrile, ketone or ether as R 61 and R 62 are methoxyformic anhydride, ethoxyformic anhydride, methyl oxalic acid anhydride, Ethyl oxalic acid anhydride, 2-cyanoacetic acid anhydride, 2-oxopropionic acid anhydride, 3-oxobutanoic acid anhydride, 4-acetylbenzoic acid anhydride, methoxyacetic acid anhydride, 4-methoxybenzoic acid anhydride, etc. And their analogs.
続いて、Ｒ６１、Ｒ６２が互いに異なる酸無水物の具体例を以下に挙げる。 Subsequently, specific examples of acid anhydrides in which R 61 and R 62 are different from each other are listed below.
Ｒ６１、Ｒ６２としては上に挙げた例、及びそれらの類縁体の全ての組み合わせが考えられるが、以下に代表的な例を挙げる。 As the examples of R 61 and R 62 , combinations of all of the above-listed examples and their analogs can be considered, but representative examples are listed below.
鎖状アルキル基同士の組み合わせの例としては、酢酸プロピオン酸無水物、酢酸ブタン酸無水物、ブタン酸プロピオン酸無水物、酢酸２－メチルプロピオン酸無水物、等が挙げられる。 Examples of combinations of linear alkyl groups include acetic propionic acid anhydride, acetic acid butanoic acid anhydride, butanoic acid propionic acid anhydride, acetic acid 2-methyl propionic acid anhydride, and the like.
鎖状アルキル基と環状アルキル基の組み合わせの例としては、酢酸シクロペンタン酸無水物、酢酸シクロヘキサン酸無水物、シクロペンタン酸プロピオン酸無水物、等が挙げられる。 Examples of the combination of a linear alkyl group and a cyclic alkyl group include acetic acid cyclopentanic acid anhydride, acetic acid cyclohexanic acid anhydride, cyclopentanic acid propionic acid anhydride, and the like.
鎖状アルキル基とアルケニル基の組み合わせの例としては、酢酸アクリル酸無水物、酢酸３－メチルアクリル酸無水物、酢酸３－ブテン酸無水物、アクリル酸プロピオン酸無水物、等が挙げられる。 Examples of the combination of a linear alkyl group and an alkenyl group include acetic acid acrylic anhydride, acetic acid 3-methylacrylic acid anhydride, acetic acid 3-butenoic acid anhydride, acrylic acid propionic acid anhydride, and the like.
鎖状アルキル基とアルキニル基の組み合わせの例としては、酢酸プロピン酸無水物、酢酸２－ブチン酸無水物、酢酸３－ブチン酸無水物、酢酸３－フェニルプロピン酸無水物プロピオン酸プロピン酸無水物、等が挙げられる。 Examples of the combination of a linear alkyl group and an alkynyl group are: acetic anhydride propynic acid anhydride, acetic acid 2-butyric acid anhydride, acetic acid 3-butyric acid anhydride, acetic acid 3-phenylpropynic acid propionic acid propionic acid anhydride , Etc.
鎖状アルキル基とアリール基の組み合わせの例としては、酢酸安息香酸無水物、酢酸４－メチル安息香酸無水物、酢酸１－ナフタレンカルボン酸無水物、安息香酸プロピオン酸無水物、等が挙げられる。 Examples of the combination of a linear alkyl group and an aryl group include acetic acid benzoic acid anhydride, acetic acid 4-methylbenzoic acid anhydride, acetic acid 1-naphthalenecarboxylic acid anhydride, benzoic acid propionic acid anhydride, and the like.
鎖状アルキル基と官能基を有する炭化水素基の組み合わせの例としては、酢酸フルオロ酢酸無水物、酢酸トリフルオロ酢酸無水物、酢酸４－フルオロ安息香酸無水物、フルオロ酢酸プロピオン酸無水物、酢酸アルキルシュウ酸無水物、酢酸２－シアノ酢酸無水物、酢酸２－オキソプロピオン酸無水物、酢酸メトキシ酢酸無水物、メトキシ酢酸プロピオン酸無水物、等が挙げられる。 Examples of the combination of a linear alkyl group and a hydrocarbon group having a functional group are: acetic anhydride, acetic anhydride, trifluoroacetic anhydride, acetic anhydride, 4-fluorobenzoic anhydride, fluoroacetic propionic anhydride, alkyl acetate Examples thereof include oxalic acid anhydride, acetic acid 2-cyanoacetic acid anhydride, acetic acid 2-oxopropionic acid anhydride, acetic acid methoxyacetic acid anhydride, methoxyacetic acid propionic acid anhydride and the like.
環状アルキル基同士の組み合わせの例としては、シクロペンタン酸シクロヘキサン酸無水物、等が挙げられる。 Examples of combinations of cyclic alkyl groups include cyclopentanoic acid cyclohexane anhydride and the like.
環状アルキル基とアルケニル基の組み合わせの例としては、アクリル酸シクロペンタン酸無水物、３－メチルアクリル酸シクロペンタン酸無水物、３－ブテン酸シクロペンタン酸無水物、アクリル酸シクロヘキサン酸無水物、等が挙げられる。 Examples of the combination of a cyclic alkyl group and an alkenyl group include acrylic acid cyclopentanic acid anhydride, 3-methylacrylic acid cyclopentanic acid anhydride, 3-butenoic acid cyclopentanic acid anhydride, acrylic acid cyclohexaneic acid anhydride, etc. Can be mentioned.
環状アルキル基とアルキニル基の組み合わせの例としては、プロピン酸シクロペンタン酸無水物、２－ブチン酸シクロペンタン酸無水物、プロピン酸シクロヘキサン酸無水物、等が挙げられる。 Examples of the combination of a cyclic alkyl group and an alkynyl group include propynoic acid cyclopentanic acid anhydride, 2-butyric acid cyclopentanic acid anhydride, propynoic acid cyclohexane acid anhydride, and the like.
環状アルキル基とアリール基の組み合わせの例としては、安息香酸シクロペンタン酸無水物、４－メチル安息香酸シクロペンタン酸無水物、安息香酸シクロヘキサン酸無水物、等が挙げられる。 Examples of the combination of a cyclic alkyl group and an aryl group include benzoic acid cyclopentanic acid anhydride, 4-methylbenzoic acid cyclopentanic acid anhydride, benzoic acid cyclohexanic acid anhydride, and the like.
環状アルキル基と官能基を有する炭化水素基の組み合わせの例としては、フルオロ酢酸シクロペンタン酸無水物、シクロペンタン酸トリフルオロ酢酸無水物、シクロペンタン酸２－シアノ酢酸無水物、シクロペンタン酸メトキシ酢酸無水物、シクロヘキサン酸フルオロ酢酸無水物、等が挙げられる。 Examples of combinations of cyclic alkyl groups and hydrocarbon groups having a functional group include fluoroacetic acid cyclopentanic acid anhydride, cyclopentanic acid trifluoroacetic acid anhydride, cyclopentanic acid 2-cyanoacetic acid anhydride, cyclopentanic acid methoxyacetic acid Anhydrides, cyclohexane acid fluoroacetic acid anhydride, etc. are mentioned.
アルケニル基同士の組み合わせの例としては、アクリル酸２－メチルアクリル酸無水物、アクリル酸３－メチルアクリル酸無水物、アクリル酸３－ブテン酸無水物、２－メチルアクリル酸３－メチルアクリル酸無水物、等が挙げられる。 As an example of the combination of alkenyl groups, acrylic acid 2-methylacrylic anhydride, acrylic acid 3-methylacrylic anhydride, acrylic acid 3-butenoic anhydride, 2-methylacrylic acid 3-methylacrylic anhydride Things, etc.
アルケニル基とアルキニル基の組み合わせの例としては、アクリル酸プロピン酸無水物、アクリル酸２－ブチン酸無水物、２－メチルアクリル酸プロピン酸無水物、等が挙げられる。 Examples of the combination of the alkenyl group and the alkynyl group include acrylic acid propynic acid anhydride, acrylic acid 2-butyric acid anhydride, 2-methyl acrylic acid propynic acid anhydride and the like.
アルケニル基とアリール基の組み合わせの例としては、アクリル酸安息香酸無水物、アクリル酸４－メチル安息香酸無水物、２－メチルアクリル酸安息香酸無水物、等が挙げられる。 Examples of the combination of the alkenyl group and the aryl group include acrylic acid benzoic acid anhydride, acrylic acid 4-methylbenzoic acid anhydride, 2-methyl acrylic acid benzoic acid anhydride, and the like.
アルケニル基と官能基を有する炭化水素基の組み合わせの例としては、アクリル酸フルオロ酢酸無水物、アクリル酸トリフルオロ酢酸無水物、アクリル酸２－シアノ酢酸無水物、アクリル酸メトキシ酢酸無水物、２－メチルアクリル酸フルオロ酢酸無水物、等が挙げられる。 Examples of the combination of alkenyl group and hydrocarbon group having a functional group include acrylic acid fluoroacetic acid anhydride, acrylic acid trifluoroacetic acid anhydride, acrylic acid 2-cyanoacetic acid anhydride, acrylic acid methoxyacetic acid anhydride, 2- Methyl acrylic acid fluoro acetic acid anhydride etc. are mentioned.
アルキニル基同士の組み合わせの例としては、プロピン酸２－ブチン酸無水物、プロピン酸３－ブチン酸無水物、２－ブチン酸３－ブチン酸無水物、等が挙げられる。 Examples of combinations of alkynyl groups include propyric acid 2-butyric acid anhydride, propyric acid 3-butyric acid anhydride, 2-butyric acid 3-butyric acid anhydride, and the like.
アルキニル基とアリール基の組み合わせの例としては、安息香酸プロピン酸無水物、４－メチル安息香酸プロピン酸無水物、安息香酸２－ブチン酸無水物、等が挙げられる。 Examples of the combination of an alkynyl group and an aryl group include propyric anhydride benzoic acid, propyric anhydride 4-methylbenzoic acid, 2-butyric anhydride benzoic acid, and the like.
アルキニル基と官能基を有する炭化水素基の組み合わせの例としては、プロピン酸フルオロ酢酸無水物、プロピン酸トリフルオロ酢酸無水物、プロピン酸２－シアノ酢酸無水物、プロピン酸メトキシ酢酸無水物、２－ブチン酸フルオロ酢酸無水物、等が挙げられる。 Examples of the combination of an alkynyl group and a hydrocarbon group having a functional group include propynoic acid fluoroacetic acid anhydride, propynoic acid trifluoroacetic acid anhydride, propynoic acid 2-cyanoacetic acid anhydride, propymic acid methoxyacetic acid anhydride, 2- Butyric acid fluoroacetic acid anhydride and the like can be mentioned.
アリール基同士の組み合わせの例としては、安息香酸４－メチル安息香酸無水物、安息香酸１－ナフタレンカルボン酸無水物、４－メチル安息香酸１－ナフタレンカルボン酸無水物、等が挙げられる。 Examples of combinations of aryl groups include benzoic acid 4-methylbenzoic acid anhydride, benzoic acid 1-naphthalenecarboxylic acid anhydride, 4-methylbenzoic acid 1-naphthalenecarboxylic acid anhydride, and the like.
アリール基と官能基を有する炭化水素基の組み合わせの例としては、安息香酸フルオロ酢酸無水物、安息香酸トリフルオロ酢酸無水物、安息香酸２－シアノ酢酸無水物、安息香酸メトキシ酢酸無水物、４－メチル安息香酸フルオロ酢酸無水物、等が挙げられる。 Examples of the combination of an aryl group and a hydrocarbon group having a functional group include benzoic acid fluoroacetic acid anhydride, benzoic acid trifluoroacetic acid anhydride, benzoic acid 2-cyanoacetic acid anhydride, benzoic acid methoxyacetic acid anhydride, 4- Methylbenzoic acid fluoroacetic acid anhydride and the like can be mentioned.
官能基を有する炭化水素基同士の組み合わせの例としては、フルオロ酢酸トリフルオロ酢酸無水物、フルオロ酢酸２－シアノ酢酸無水物、フルオロ酢酸メトキシ酢酸無水物、トリフルオロ酢酸２－シアノ酢酸無水物、等が挙げられる。 Examples of combinations of hydrocarbon groups having a functional group include fluoroacetic acid trifluoroacetic acid anhydride, fluoroacetic acid 2-cyanoacetic acid anhydride, fluoroacetic acid methoxyacetic acid anhydride, trifluoroacetic acid 2-cyanoacetic acid anhydride, etc. Can be mentioned.
上記の鎖状構造を形成している酸無水物のうち好ましくは、無水酢酸、プロピオン酸無水物、２－メチルプロピオン酸無水物、シクロペンタンカルボン酸無水物、シクロヘキサンカルボン酸無水物等、アクリル酸無水物、２－メチルアクリル酸無水物、３－メチルアクリル酸無水物、２，３－ジメチルアクリル酸無水物、３，３－ジメチルアクリル酸無水物、３－ブテン酸無水物、２－メチル－３－ブテン酸無水物、プロピン酸無水物、２－ブチン酸無水物、安息香酸無水物、２－メチル安息香酸無水物、４－メチル安息香酸無水物、４－ｔｅｒｔ－ブチル安息香酸無水物、トリフルオロ酢酸無水物、３，３，３－トリフルオロプロピオン酸無水物、２－（トリフルオロメチル）アクリル酸無水物、２－（４－フルオロフェニル）アクリル酸無水物、４－フルオロ安息香酸無水物、２，３，４，５，６－ペンタフルオロ安息香酸無水物、メトキシギ酸無水物、エトキシギ酸無水物、であり、より好ましくは、アクリル酸無水物、２－メチルアクリル酸無水物、３－メチルアクリル酸無水物、安息香酸無水物、２－メチル安息香酸無水物、４－メチル安息香酸無水物、４－ｔｅｒｔ－ブチル安息香酸無水物、４－フルオロ安息香酸無水物、２，３，４，５，６－ペンタフルオロ安息香酸無水物、メトキシギ酸無水物、エトキシギ酸無水物である。 Among the acid anhydrides forming the above chain structure, preferred are acetic anhydride, propionic acid anhydride, 2-methylpropionic acid anhydride, cyclopentanecarboxylic acid anhydride, cyclohexane carboxylic acid anhydride, etc., acrylic acid Anhydride, 2-methylacrylic anhydride, 3-methylacrylic anhydride, 2,3-dimethylacrylic anhydride, 3, 3-dimethylacrylic anhydride, 3-butenoic anhydride, 2-methyl- 3-butenoic acid anhydride, propynic acid anhydride, 2-butyric acid anhydride, benzoic acid anhydride, 2-methylbenzoic acid anhydride, 4-methylbenzoic acid anhydride, 4-tert-butylbenzoic acid anhydride, Trifluoroacetic acid anhydride, 3,3,3-trifluoropropionic acid anhydride, 2- (trifluoromethyl) acrylic acid anhydride, 2- (4-fluorophenyl) acrylic acid Water, 4-fluorobenzoic acid anhydride, 2,3,4,5,6-pentafluorobenzoic acid anhydride, methoxyformic acid anhydride, ethoxyformic acid anhydride, more preferably acrylic acid anhydride, 2-methylacrylic anhydride, 3-methylacrylic anhydride, benzoic anhydride, 2-methylbenzoic anhydride, 4-methylbenzoic anhydride, 4-tert-butylbenzoic anhydride, 4-fluoro Benzoic anhydride, 2,3,4,5,6-pentafluorobenzoic anhydride, methoxyformic anhydride, ethoxyformic anhydride.
これらの化合物は、適切にリチウムオキサラート塩との結合を形成して耐久性に優れる皮膜を形成することで、特に耐久試験後の充放電レート特性、入出力特性、インピーダンス特性を向上させることができる観点で好ましい。 These compounds can improve the charge / discharge rate characteristics, the input / output characteristics, and the impedance characteristics after the durability test, in particular, by forming a bond with a lithium oxalate salt appropriately to form a film excellent in durability. It is preferable from the viewpoint of
なお、上記カルボン酸無水物の分子量に制限は無く、本発明の効果を著しく損なわない限り任意であるが、通常９０以上、好ましくは９５以上であり、一方、通常３００以下、好ましくは２００以下である。カルボン酸無水物の分子量が上記範囲内であると、電解液の粘度上昇を抑制でき、かつ皮膜密度が適正化されるために耐久性を適切に向上することができる。 The molecular weight of the carboxylic acid anhydride is not limited as long as the effects of the present invention are not significantly impaired, but is usually 90 or more, preferably 95 or more, and 300 or less, preferably 200 or less. is there. When the molecular weight of the carboxylic acid anhydride is in the above range, the increase in viscosity of the electrolytic solution can be suppressed, and the film density can be optimized, so that the durability can be appropriately improved.
また、上記カルボン酸無水物の製造方法にも特に制限は無く、公知の方法を任意に選択して製造することが可能である。以上説明したカルボン酸無水物は、本発明の非水系電解液中に、何れか１種を単独で含有させてもよく、２種以上を任意の組み合わせ及び比率で併有させてもよい。 Moreover, there is no restriction | limiting in particular also in the manufacturing method of the said carboxylic anhydride, It is possible to select and manufacture a well-known method arbitrarily. The carboxylic acid anhydride described above may contain any one type alone in the non-aqueous electrolyte solution of the present invention, or two or more types in any combination and ratio.
また、本発明の電解液に対する上記カルボン酸無水物の含有量に特に制限は無く、本発明の効果を著しく損なわない限り任意であるが、本発明の電解液に対して、通常０．０１質量％以上、好ましくは０．１質量％以上、また、通常５質量％以下、好ましくは３質量％以下の濃度で含有させることが望ましい。カルボン酸無水物の含有量が上記範囲内であると、サイクル特性向上効果が発現しやすくなり、また反応性が好適であるため電池特性が向上しやすくなる。 There is no particular limitation on the content of the above-mentioned carboxylic anhydride with respect to the electrolytic solution of the present invention, and it is optional as long as the effects of the present invention are not significantly impaired. It is desirable to contain at a concentration of% or more, preferably 0.1% by mass or more, and usually 5% by mass or less, preferably 3% by mass or less. When the content of the carboxylic acid anhydride is in the above range, the effect of improving the cycle characteristics is easily exhibited, and since the reactivity is suitable, the battery characteristics are easily improved.
本発明の電解液には、公知のその他の助剤を用いることができる。その他の助剤としては、エリスリタンカーボネート、スピロ－ビス－ジメチレンカーボネート、メトキシエチル－メチルカーボネート等のカーボネート化合物；２，４，８，１０－テトラオキサスピロ［５．５］ウンデカン、３，９－ジビニル－２，４，８，１０－テトラオキサスピロ［５．５］ウンデカン等のスピロ化合物；エチレンサルファイト、フルオロスルホン酸メチル、フルオロスルホン酸エチル、メタンスルホン酸メチル、メタンスルホン酸エチル、ブスルファン、スルホレン、硫酸エチレン、硫酸ビニレン、ジフェニルスルホン、Ｎ，Ｎ－ジメチルメタンスルホンアミド、Ｎ，Ｎ－ジエチルメタンスルホンアミド、アセトアミド、Ｎ－メチルホルムアミド、Ｎ，Ｎ－ジメチルホルムアミド、Ｎ，Ｎ－ジメチルアセトアミド、ビニルスルホン酸メチル、ビニルスルホン酸エチル、ビニルスルホン酸アリル、ビニルスルホン酸プロパルギル、アリルスルホン酸メチル、アリルスルホン酸エチル、アリルスルホン酸アリル、アリルスルホン酸プロパルギル、１，２－ビス（ビニルスルホニロキシ）エタン、無水プロパンジスルホン酸、無水スルホ酪酸、無水スルホ安息香酸、無水スルホプロピオン酸、無水エタンジスルホン酸、メチレンメタンジスルホネート、メタンスルホン酸　２－プロピニル、ペンテンサルファイト、ペンタフルオロフェニルメタンスルホネート、プロピレンサルフェート、プロピレンサルファイト、プロパンサルトン、ブチレンサルファイト、ブタン－２，３－ジイル　ジメタンスルホネート、２－ブチン－１，４－ジイルジメタンスルホネート、２－フェニルビシクロヘキシル、２－ブチン－１，４－ジイルジホルメート、ビニルスルホン酸　２－プロピニル、ビス（２－ビニルスルホニルエチル）エーテル、５－ビニル－ヘキサヒドロ－１，３，２－ベンゾジオキサチオール－２－オキシド、２－（メタンスルホニルオキシ）プロピオン酸２－プロピニル、５，５－ジメチル－１，２－オキサチオラン－４－オン　２，２－ジオキシド、３－スルホ－プロピオン酸無水物トリメチレンメタンジスルホネート２－メチルテトラヒドロフラン、トリメチレンメタンジスルホネート、テトラメチレンスルホキシド、ジメチレンメタンジスルホネート、ジフルオロエチルメチルスルホン、ジビニルスルホン、１，２－ビス（ビニルスルホニル）エタン、エチレンビスホスホン酸メチル、エチレンビスホスホン酸エチル、エチレンサルフェート等の含硫黄化合物；１－メチル－２－ピロリジノン、１－メチル－２－ピペリドン、３－メチル－２－オキサゾリジノン、１，３－ジメチル－２－イミダゾリジノン及びＮ－メチルスクシンイミド、ニトロメタン、ニトロエタン、チオフェン１－オキシド、エチレンジアミン等の含窒素化合物；亜リン酸トリメチル、亜リン酸トリエチル、亜リン酸トリフェニル、リン酸トリメチル、リン酸トリエチル、リン酸トリフェニル、メチルホスホン酸ジメチル、エチルホスホン酸ジエチル、ビニルホスホン酸ジメチル、ビニルホスホン酸ジエチル、ジエチルホスホノ酢酸エチル、ジメチルホスフィン酸メチル、ジエチルホスフィン酸エチル、トリメチルホスフィンオキシド、トリエチルホスフィンオキシド、リン酸ビス（２，２－ジフルオロエチル）２，２，２－トリフルオロエチル、リン酸ビス（２，２，３，３－テトラフルオロプロピル）２，２，２－トリフルオロエチル、リン酸ビス（２，２，２－トリフルオロエチル）メチル、リン酸ビス（２，２，２－トリフルオロエチル）エチル、リン酸ビス（２，２，２－トリフルオロエチル）２，２－ジフルオロエチルリン酸ビス（２，２，２－トリフルオロエチル）２，２，３，３－テトラフルオロプロピル、リン酸トリブチル、リン酸トリス（２，２，２－トリフルオロエチル）、リン酸トリス（１，１，１，３，３，３－ヘキサフルオロプロパン－２－イル）、リン酸トリオクチル、リン酸２－フェニルフェニルジメチル、リン酸２－フェニルフェニルジエチル、リン酸（２，２，２－トリフルオロエチル）（２，２，３，３－テトラフルオロプロピル）メチル、リン酸トリエステル、メチレンビスホスホン酸メチル、メチレンビスホスホン酸エチル、メチル　２－（ジメトキシホスホリル）アセテート、メチル　２－（ジメチルホスホリル）アセテート、メチル　２－（ジエトキシホスホリル）アセテート、メチル　２－（ジエチルホスホリル）アセテート、ブチレンビスホスホン酸メチル、ブチレンビスホスホン酸エチル、２－プロピニル　２－（ジメトキシホスホリル）アセテート、２－プロピニル　２－（ジメチルホスホリル）アセテート、２－プロピニル　２－（ジエトキシホスホリル）アセテート、２－プロピニル　２－（ジエチルホスホリル）アセテート、トリス（トリメチルシリル）ホスフェート、トリス（トリメチルシリル）ホスファイト、トリス（トリエチルシリル）ホスフェート、トリス（トリエチルシリル）ホスファイト等の含燐化合物；ヘプタン、オクタン、ノナン、デカン、シクロヘプタン、メチルホルメート、メチル　２－プロピニルオギザレート、メタクリル酸　２－プロピニル、マロン酸ジメチル、マロン酸エステル、ペンタン、ベンゼン、フラン、ナフタレン、２，５，８，１１－テトラオキサドデカン、２，５，８，１１，１４－ペンタオキサペンタデカン、３－ペンタノン、２－フェニルビシクロヘキシル、３－アリル無水コハク酸、エトキシメトキシエタン、トリメトキシメタン、シクロヘキサン等の炭化水素化合物；フルオロベンゼン、ジフルオロベンゼン、ヘキサフルオロベンゼン、ベンゾトリフルオライド、モノフルオロベンゼン、１－フルオロ－２－シクロヘキシルベンゼン、１－フルオロ－４－ｔｅｒｔ－ブチルベンゼン、１－フルオロ－３－シクロヘキシルベンゼン、１－フルオロ－２－シクロヘキシルベンゼン、フッ素化ビフェニル等の含フッ素芳香族化合物；ホウ酸トリス（トリメチルシリル）、ホウ酸トリス（トリメトキシシリル）、リン酸トリス（トリメチルシリル）、リン酸トリス（トリメトキシシリル）、ジメトキシアルミノキシトリメトキシシラン、ジエトキシアルミノキシトリエトキシシラン、ジプロポキシアルミノキシトリエトキシシラン、ジブトキシアルミノキシトリメトキシシラン、ジブトキシアルミノキシトリエトキシシラン、チタンテトラキス（トリメチルシロキシド）、チタンテトラキス（トリエチルシロキシド）１、亜リン酸トリス（トリメチルシリル）、ポリリン酸トリメチルシリル、テトラメチルシラン等のシラン化合物；ジメチルオキサレート、ジオキソラン、ジオキサン、ジメチルケトン、ジエチルケトン、ジエチルオキサレート、ジ（２－プロピニル）オギザレート、コハク酸ジメチル、グルタル酸　ジ（２－プロピニル）、ギ酸　２－プロピニル、ギ酸エチル、グライム、エチルモノグライム、エチルメチルオキサレート、エチルホルメート、等の含酸素化合物等が挙げられる。これらは１種を単独で用いても、２種以上を併用してもよい。これらの助剤を添加することにより、高温保存後の容量維持特性やサイクル特性を向上させることができる。 Other known auxiliary agents can be used in the electrolytic solution of the present invention. Other auxiliary agents include carbonate compounds such as erythritan carbonate, spiro-bis-dimethylene carbonate, methoxyethyl-methyl carbonate and the like; 2,4,8,10-tetraoxaspiro [5.5] undecane, 3,9 Spiro compounds such as divinyl-2,4,8,10-tetraoxaspiro [5.5] undecane; ethylene sulfite, methyl fluorosulfonate, ethyl fluorosulfonate, methyl methanesulfonate, ethyl methanesulfonate, busulfan , Sulfolene, ethylene sulfate, vinylene sulfate, diphenyl sulfone, N, N-dimethyl methane sulfonamide, N, N-diethyl methane sulfonamide, acetamide, N-methyl formamide, N, N-dimethylformamide, N, N-dimethyl acetamide , B Methyl sulfonate, ethyl vinyl sulfonate, allyl vinyl sulfonate, propargyl vinyl sulfonate, methyl allyl sulfonate, ethyl allyl sulfonate, allyl allyl sulfonate, propargyl allyl sulfonate, 1,2-bis (vinyl sulfonyloxy) Ethane, propanedisulfonic acid anhydride, sulfobutyric anhydride, sulfobenzoic acid anhydride, sulfobenzoic acid anhydride, sulfopropionic acid anhydride, ethanedisulfonic acid anhydride, methylene methane disulfonate, 2-propynyl methanesulfonic acid, penten sulfite, pentafluorophenyl methane sulfonate, propylene sulfate Propylene sulfite, propane sultone, butylene sulfite, butane-2,3-diyl dimethane sulfonate, 2-butyne-1,4-diyl dimethane sulfonate, -Phenylbicyclohexyl, 2-butyne-1,4-diyl diformate, vinyl sulfonic acid 2-propynyl, bis (2-vinylsulfonylethyl) ether, 5-vinyl-hexahydro-1,3,2-benzodioxa Thiol-2-oxide, 2-propynyl 2- (methanesulfonyloxy) propionate, 5,5-dimethyl-1,2-oxathiolan-4-one 2,2-dioxide, 3-sulfo-propionic anhydride trimethylene Methanedisulfonate 2-methyltetrahydrofuran, trimethylenemethanedisulfonate, tetramethylene sulfoxide, dimethylene methanedisulfonate, difluoroethyl methyl sulfone, divinyl sulfone, 1,2-bis (vinylsulfonyl) ethane, methyl ethylene bisphosphonate, ethylene Sulfur-containing compounds such as ethyl bisphosphonate and ethylene sulfate; 1-methyl-2-pyrrolidinone, 1-methyl-2-piperidone, 3-methyl-2-oxazolidinone, 1,3-dimethyl-2-imidazolidinone and N- Nitrogen containing compounds such as methyl succinimide, nitromethane, nitroethane, thiophene 1-oxide, ethylene diamine; trimethyl phosphite, triethyl phosphite, triphenyl phosphite, trimethyl phosphate, triethyl phosphate, triphenyl phosphate, methyl phosphonic acid Dimethyl, diethyl ethylphosphonate, dimethyl vinylphosphonate, diethyl vinylphosphonate, ethyl diethylphosphonoacetate, methyl dimethylphosphinate, ethyl diethylphosphinate, trimethylphosphine oxide, triethylphosphine oxide Phosphate, bis (2,2-difluoroethyl) 2,2,2-trifluoroethyl phosphate, bis (2,2,3,3-tetrafluoropropyl) phosphate 2,2,2-trifluoroethyl, phosphorus Acid bis (2,2,2-trifluoroethyl) methyl phosphate, bis (2,2,2-trifluoroethyl) ethyl phosphate, bis (2,2,2-trifluoroethyl) phosphate 2,2-difluoro Ethyl phosphate bis (2,2,2-trifluoroethyl) 2,2,3,3-tetrafluoropropyl, tributyl phosphate, tris (2,2,2-trifluoroethyl) phosphate, tris phosphate 1,1,1,3,3,3-hexafluoropropan-2-yl), trioctyl phosphate, 2-phenylphenyl dimethyl phosphate, 2-phenylphenyl diethyl phosphate, phosphoric acid (2,2,2 Trifluoroethyl) (2,2,3,3-tetrafluoropropyl) methyl, phosphotriester, methyl methylene bisphosphonate, ethyl methylene bisphosphonate, methyl 2- (dimethoxyphosphoryl) acetate, methyl 2- (dimethylphosphoryl) Acetate, methyl 2- (diethoxyphosphoryl) acetate, methyl 2- (diethylphosphoryl) acetate, methyl butylene bisphosphonate, ethyl butylene bisphosphonate, 2-propynyl 2- (dimethoxyphosphoryl) acetate, 2-propynyl 2- (dimethylphosphoryl ) Acetate, 2-propynyl 2- (diethoxyphosphoryl) acetate, 2-propynyl 2- (diethylphosphoryl) acetate, tris (trimethylsilyl) phosphate, tris ( Phosphorus-containing compounds such as trimethylsilyl) phosphite, tris (triethylsilyl) phosphate and tris (triethylsilyl) phosphite; heptane, octane, nonane, decane, cycloheptane, methyl formate, methyl 2-propynyl ogvalate, methacrylic acid 2-propynyl, dimethyl malonate, malonic ester, pentane, benzene, furan, naphthalene, 2,5,8,11-tetraoxadodecane, 2,5,8,11,14-pentaoxapentadecane, 3-pentanone, Hydrocarbon compounds such as 2-phenylbicyclohexyl, 3-allyl succinic anhydride, ethoxymethoxyethane, trimethoxymethane, cyclohexane and the like; fluorobenzene, difluorobenzene, hexafluorobenzene, benzotrifluoride, mono Fluorine-containing aromatic compounds such as fluorobenzene, 1-fluoro-2-cyclohexylbenzene, 1-fluoro-4-tert-butylbenzene, 1-fluoro-3-cyclohexylbenzene, 1-fluoro-2-cyclohexylbenzene, fluorinated biphenyl Tris (trimethylsilyl) borate, tris (trimethoxysilyl) borate, tris (trimethylsilyl) phosphate, tris (trimethoxysilyl) phosphate, dimethoxyaluminoxytrimethoxysilane, diethoxyaluminoxytriethoxysilane, dipropoxy propoxy Aluminoxytriethoxysilane, dibutoxyaluminoxytrimethoxysilane, dibutoxyaluminoxytriethoxysilane, titanium tetrakis (trimethylsiloxide), titanium tetrakis (triethylsiloxide) Silane compounds such as tris (trimethylsilyl) phosphite, trimethylsilyl polyphosphate and tetramethylsilane; dimethyl oxalate, dioxolane, dioxane, dimethyl ketone, diethyl ketone, diethyl oxalate, di (2-propynyl) oxalate, dimethyl succinate And oxygenated compounds such as glutaric acid di (2-propynyl), formic acid 2-propynyl, ethyl formate, glyme, ethyl monoglyme, ethyl methyl oxalate, ethyl formate and the like. These may be used alone or in combination of two or more. By adding these assistants, capacity retention characteristics and cycle characteristics after high temperature storage can be improved.
上記その他の助剤としては、なかでも、含燐化合物が好ましく、トリス（トリメチルシリル）ホスフェートが好ましい。 Among the above auxiliary agents, phosphorus-containing compounds are preferable, and tris (trimethylsilyl) phosphate is preferable.
その他の助剤の配合量は、特に制限されず、本発明の効果を著しく損なわない限り任意である。その他の助剤は、電解液１００質量％中、好ましくは、０．０１質量％以上であり、また、５質量％以下である。この範囲であれば、その他助剤の効果が十分に発現させやすく、高負荷放電特性等の電池の特性が低下するといった事態も回避しやすい。その他の助剤の配合量は、より好ましくは０．１質量％以上、更に好ましくは０．２質量％以上であり、また、より好ましくは３質量％以下、更に好ましくは１質量％以下である。 The amount of the other auxiliary agent is not particularly limited, and is optional unless the effects of the present invention are significantly impaired. The other auxiliary agent is preferably 0.01% by mass or more and 5% by mass or less in 100% by mass of the electrolytic solution. Within this range, the effects of the other auxiliary agents can be sufficiently exhibited, and situations in which battery characteristics such as high load discharge characteristics are degraded can be easily avoided. The compounding amount of the other auxiliary agent is more preferably 0.1% by mass or more, still more preferably 0.2% by mass or more, and more preferably 3% by mass or less, still more preferably 1% by mass or less .
本発明の電解液は、本発明の効果を損なわない範囲で、環状及び鎖状カルボン酸エステル、エーテル化合物、窒素含有化合物、ホウ素含有化合物、有機ケイ素含有化合物、不燃（難燃）化剤、界面活性剤、高誘電化添加剤、サイクル特性及びレート特性改善剤、スルホン系化合物等を添加剤として更に含有してもよい。 The electrolytic solution of the present invention is a cyclic and linear carboxylic acid ester, an ether compound, a nitrogen-containing compound, a boron-containing compound, an organic silicon-containing compound, an incombustible (flame retardant) agent, an interface, as long as the effects of the present invention are not impaired. Activators, high dielectric additives, cycle characteristics and rate characteristics improvers, sulfone compounds and the like may further be contained as additives.
上記環状カルボン酸エステルとしては、その構造式中の全炭素原子数が３～１２のものが挙げられる。具体的には、ガンマブチロラクトン、ガンマバレロラクトン、ガンマカプロラクトン、イプシロンカプロラクトン、３－メチル－γ－ブチロラクトン等が挙げられる。中でも、ガンマブチロラクトンがリチウムイオン解離度の向上に由来する電気化学デバイスの特性向上の点から特に好ましい。 Examples of the cyclic carboxylic acid ester include those having 3 to 12 carbon atoms in total in the structural formula. Specific examples thereof include gamma-butyrolactone, gamma-valerolactone, gamma-caprolactone, epsilon-caprolactone, 3-methyl-γ-butyrolactone and the like. Among them, gamma-butyrolactone is particularly preferable from the viewpoint of the improvement of the characteristics of the electrochemical device derived from the improvement of the lithium ion dissociation degree.
添加剤としての環状カルボン酸エステルの配合量は、通常、溶媒１００質量％中、好ましくは０．１質量％以上、より好ましくは１質量％以上である。この範囲であると、電解液の電気伝導率を改善し、電気化学デバイスの大電流放電特性を向上させやすくなる。また、環状カルボン酸エステルの配合量は、好ましくは１０質量％以下、より好ましくは５質量％以下である。このように上限を設定することにより、電解液の粘度を適切な範囲とし、電気伝導率の低下を回避し、負極抵抗の増大を抑制し、電気化学デバイスの大電流放電特性を良好な範囲としやすくする。 The compounding amount of the cyclic carboxylic acid ester as the additive is usually 0.1% by mass or more, preferably 1% by mass or more, in 100% by mass of the solvent. Within this range, the electrical conductivity of the electrolytic solution can be improved, and the large current discharge characteristics of the electrochemical device can be easily improved. Moreover, the compounding quantity of cyclic carboxylic acid ester becomes like this. Preferably it is 10 mass% or less, More preferably, it is 5 mass% or less. By setting the upper limit in this way, the viscosity of the electrolytic solution is made into an appropriate range, the decrease of the electric conductivity is avoided, the increase of the negative electrode resistance is suppressed, and the large current discharge characteristics of the electrochemical device is made into a good range. Make it easy.
また、上記環状カルボン酸エステルとしては、フッ素化環状カルボン酸エステル（含フッ素ラクトン）も好適に用いることができる。含フッ素ラクトンとしては、例えば、下記式（Ｃ）： Moreover, as said cyclic carboxylic acid ester, fluorinated cyclic carboxylic acid ester (fluorine-containing lactone) can also be used suitably. As the fluorine-containing lactone, for example, the following formula (C):
Figure JPOXMLDOC01-appb-C000080
Figure JPOXMLDOC01-appb-C000080
（式中、Ｘ１５～Ｘ２０は同じか又は異なり、いずれも－Ｈ、－Ｆ、－Ｃｌ、－ＣＨ３又はフッ素化アルキル基；ただし、Ｘ１５～Ｘ２０の少なくとも１つはフッ素化アルキル基である）
で示される含フッ素ラクトンが挙げられる。 (Wherein, X 15 to X 20 are the same or different, and each is —H, —F, —Cl, —CH 3 or a fluorinated alkyl group; provided that at least one of X 15 to X 20 is a fluorinated alkyl group Is the group)
And fluorine-containing lactones represented by
Ｘ１５～Ｘ２０におけるフッ素化アルキル基としては、例えば、－ＣＦＨ２、－ＣＦ２Ｈ、－ＣＦ３、－ＣＨ２ＣＦ３、－ＣＦ２ＣＦ３、－ＣＨ２ＣＦ２ＣＦ３、－ＣＦ（ＣＦ３）２等が挙げられ、耐酸化性が高く、安全性向上効果がある点から－ＣＨ２ＣＦ３、－ＣＨ２ＣＦ２ＣＦ３が好ましい。 As a fluorinated alkyl group in X 15 to X 20 , for example, -CFH 2 , -CF 2 H, -CF 3 , -CH 2 CF 3 , -CF 2 CF 3 , -CH 2 CF 2 CF 3 , -CF (CF 3 ) 2 and the like, and from the viewpoint of high oxidation resistance and safety improving effect, —CH 2 CF 3 and —CH 2 CF 2 CF 3 are preferable.
Ｘ１５～Ｘ２０の少なくとも１つがフッ素化アルキル基であれば、－Ｈ、－Ｆ、－Ｃｌ、－ＣＨ３又はフッ素化アルキル基は、Ｘ１５～Ｘ２０の１箇所のみに置換していてもよいし、複数の箇所に置換していてもよい。好ましくは、電解質塩の溶解性が良好な点から１～３箇所、更に好ましくは１～２箇所である。 When at least one of X 15 to X 20 is a fluorinated alkyl group, -H, -F, -Cl, -CH 3 or a fluorinated alkyl group is substituted at only one position of X 15 to X 20 and It may be replaced with a plurality of places. From the viewpoint of good solubility of the electrolyte salt, it is preferably one to three, and more preferably one to two.
フッ素化アルキル基の置換位置は特に限定されないが、合成収率が良好なことから、Ｘ１７及び／又はＸ１８が、特にＸ１７又はＸ１８がフッ素化アルキル基、なかでも－ＣＨ２ＣＦ３、－ＣＨ２ＣＦ２ＣＦ３であることが好ましい。フッ素化アルキル基以外のＸ１５～Ｘ２０は、－Ｈ、－Ｆ、－Ｃｌ又はＣＨ３であり、特に電解質塩の溶解性が良好な点から－Ｈが好ましい。 But it is not fluorinated alkyl group substituted position particularly limited to, since the synthesis yields good, X 17 and / or X 18 is, in particular X 17 or X 18 is a fluorinated alkyl group, inter alia -CH 2 CF 3 And —CH 2 CF 2 CF 3 is preferable. X 15 to X 20 other than the fluorinated alkyl group are —H, —F, —Cl or CH 3 , and in particular, —H is preferable from the viewpoint of good solubility of the electrolyte salt.
含フッ素ラクトンとしては、上記式で示されるもの以外にも、例えば、下記式（Ｄ）： As the fluorine-containing lactone, in addition to the one represented by the above formula, for example, the following formula (D):
Figure JPOXMLDOC01-appb-C000081
Figure JPOXMLDOC01-appb-C000081
（式中、Ａ及びＢはいずれか一方がＣＸ２２６Ｘ２２７（Ｘ２２６及びＸ２２７は同じか又は異なり、いずれも－Ｈ、－Ｆ、－Ｃｌ、－ＣＦ３、－ＣＨ３又は水素原子がハロゲン原子で置換されていてもよくヘテロ原子を鎖中に含んでいてもよいアルキレン基）であり、他方は酸素原子；Ｒｆ１２はエーテル結合を有していてもよいフッ素化アルキル基又はフッ素化アルコキシ基；Ｘ２２１及びＸ２２２は同じか又は異なり、いずれも－Ｈ、－Ｆ、－Ｃｌ、－ＣＦ３又はＣＨ３；Ｘ２２３～Ｘ２２５は同じか又は異なり、いずれも－Ｈ、－Ｆ、－Ｃｌ又は水素原子がハロゲン原子で置換されていてもよくヘテロ原子を鎖中に含んでいてもよいアルキル基；ｎ＝０又は１）
で示される含フッ素ラクトン等も挙げられる。 (Wherein, A and B each represent one of CX 226 X 227 (wherein X 226 and X 227 are the same or different, and each represents -H, -F, -Cl, -CF 3 , -CH 3 or a hydrogen atom An alkylene group which may be substituted by a halogen atom and which may contain a hetero atom in the chain, and the other is an oxygen atom; R f 12 is a fluorinated alkyl group which may have an ether bond or fluorinated Alkoxy groups; X 221 and X 222 are the same or different, and all are -H, -F, -Cl, -CF 3 or CH 3 ; and X 223 to X 225 are the same or different, all are -H, -F , -Cl or an alkyl group whose hydrogen atom may be substituted with a halogen atom and may contain a hetero atom in the chain; n = 0 or 1)
And the like.
式（Ｄ）で示される含フッ素ラクトンとしては、下記式（Ｅ）： As the fluorine-containing lactone represented by the formula (D), the following formula (E):
Figure JPOXMLDOC01-appb-C000082
Figure JPOXMLDOC01-appb-C000082
（式中、Ａ、Ｂ、Ｒｆ１２、Ｘ２２１、Ｘ２２２及びＸ２２３は式（Ｄ）と同じである）
で示される５員環構造が、合成が容易である点、化学的安定性が良好な点から好ましく挙げられ、更には、ＡとＢの組合せにより、下記式（Ｆ）： (Wherein, A, B, R f 12 , X 221 , X 222 and X 223 are the same as in formula (D))
The five-membered ring structure represented by is preferably exemplified from the viewpoint of easy synthesis and good chemical stability, and further, by the combination of A and B, the following formula (F):
Figure JPOXMLDOC01-appb-C000083
Figure JPOXMLDOC01-appb-C000083
（式中、Ｒｆ１２、Ｘ２２１、Ｘ２２２、Ｘ２２３、Ｘ２２６及びＸ２２７は式（Ｄ）と同じである）
で示される含フッ素ラクトンと、下記式（Ｇ）： (Wherein, Rf 12 , X 221 , X 222 , X 223 , X 226 and X 227 are the same as in formula (D))
And a fluorine-containing lactone represented by the following formula (G):
Figure JPOXMLDOC01-appb-C000084
Figure JPOXMLDOC01-appb-C000084
（式中、Ｒｆ１２、Ｘ２２１、Ｘ２２２、Ｘ２２３、Ｘ２２６及びＸ２２７は式（Ｄ）と同じである）
で示される含フッ素ラクトンがある。 (Wherein, Rf 12 , X 221 , X 222 , X 223 , X 226 and X 227 are the same as in formula (D))
There is a fluorine-containing lactone shown by
これらのなかでも、高い誘電率、高い耐電圧といった優れた特性が特に発揮できる点、そのほか電解質塩の溶解性、内部抵抗の低減が良好な点で本発明における電解液としての特性が向上する点から、 Among these, particularly excellent characteristics such as high dielectric constant and high withstand voltage can be exhibited, and in addition, the characteristics as the electrolytic solution in the present invention are improved in that the solubility of the electrolyte salt and the reduction in internal resistance are good. From
Figure JPOXMLDOC01-appb-C000085
 等が挙げられる。
フッ素化環状カルボン酸エステルを含有させることにより、イオン伝導度の向上、安全性の向上、高温時の安定性向上といった効果が得られる。
Figure JPOXMLDOC01-appb-C000085
 Etc.
By containing a fluorinated cyclic carboxylic acid ester, effects such as improvement of ion conductivity, improvement of safety, and improvement of stability at high temperature can be obtained.
上記鎖状カルボン酸エステルとしては、その構造式中の全炭素数が３～７のものが挙げられる。具体的には、酢酸メチル、酢酸エチル、酢酸－ｎ－プロピル、酢酸イソプロピル、酢酸－ｎ－ブチル、酢酸イソブチル、酢酸－ｔ－ブチル、プロピオン酸メチル、プロピオン酸エチル、プロピオン酸－ｎ－プロピル、プロピオン酸イソブチル、プロピオン酸－ｎ－ブチル、メチルブチレート、プロピオン酸イソブチル、プロピオン酸－ｔ－ブチル、酪酸メチル、酪酸エチル、酪酸－ｎ－プロピル、酪酸イソプロピル、イソ酪酸メチル、イソ酪酸エチル、イソ酪酸－ｎ－プロピル、イソ酪酸イソプロピル等が挙げられる。 Examples of the above-mentioned linear carboxylic acid ester include those having 3 to 7 carbon atoms in total in the structural formula. Specifically, methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, t-butyl acetate, methyl propionate, ethyl propionate, n-propyl propionate, Isobutyl propionate, n-butyl propionate, methyl butyrate, isobutyl propionate, t-butyl propionate, methyl butyrate, ethyl butyrate, n-propyl butyrate, isopropyl butyrate, methyl isobutyrate, ethyl isobutyrate, isobutyrate Butyric acid-n-propyl, isopropyl isobutyrate and the like can be mentioned.
中でも、酢酸メチル、酢酸エチル、酢酸－ｎ－プロピル、酢酸－ｎ－ブチル、プロピオン酸メチル、プロピオン酸エチル、プロピオン酸－ｎ－プロピル、プロピオン酸イソプロピル、酪酸メチル、酪酸エチル等が粘度低下によるイオン伝導度の向上の点から好ましい。 Among them, methyl acetate, ethyl acetate, n-propyl acetate, n-butyl acetate, methyl propionate, ethyl propionate, n-propyl propionate, isopropyl propionate, methyl butyrate, ethyl butyrate, etc. ions due to viscosity decrease It is preferable from the point of improvement of conductivity.
上記エーテル化合物としては、炭素数２～１０の鎖状エーテル、及び炭素数３～６の環状エーテルが好ましい。
炭素数２～１０の鎖状エーテルとしては、ジメチルエーテル、ジエチルエーテル、ジ－ｎ－ブチルエーテル、ジメトキシメタン、メトキシエトキシメタン、ジエトキシメタン、ジメトキシエタン、メトキシエトキシエタン、ジエトキシエタン、エチレングリコールジ－ｎ－プロピルエーテル、エチレングリコールジ－ｎ－ブチルエーテル、ジエチレングリコール、ジエチレングリコールジメチルエーテル、ペンタエチレングリコール、トリエチレングリコールジメチルエーテル、トリエチレングリコール、テトラエチレングリコール、テトラエチレングリコールジメチルエーテル、ジイソプロピルエーテル等が挙げられる。 The ether compound is preferably a C2-C10 linear ether and a C3-C6 cyclic ether.
The linear ether having 2 to 10 carbons includes dimethyl ether, diethyl ether, di-n-butyl ether, dimethoxymethane, methoxyethoxymethane, diethoxymethane, dimethoxyethane, methoxyethoxyethane, diethoxyethane, ethylene glycol di-n And -propyl ether, ethylene glycol di-n-butyl ether, diethylene glycol, diethylene glycol dimethyl ether, pentaethylene glycol, triethylene glycol dimethyl ether, triethylene glycol, tetraethylene glycol, tetraethylene glycol dimethyl ether, diisopropyl ether and the like.
また、上記エーテル化合物としては、フッ素化エーテルも好適に用いることができる。
上記フッ素化エーテルとしては、下記一般式（Ｉ）：
Ｒｆ３－Ｏ－Ｒｆ４　　　　　　　（Ｉ）
（式中、Ｒｆ３及びＲｆ４は同じか又は異なり、炭素数１～１０のアルキル基又は炭素数１～１０のフッ素化アルキル基である。ただし、Ｒｆ３及びＲｆ４の少なくとも一方は、フッ素化アルキル基である。）
で表されるフッ素化エーテル（Ｉ）が挙げられる。フッ素化エーテル（Ｉ）を含有させることにより、電解液の難燃性が向上するとともに、高温高電圧での安定性、安全性が向上する。 Moreover, as said ether compound, a fluorinated ether can also be used suitably.
As said fluorinated ether, the following general formula (I):
Rf 3 -O-Rf 4 (I)
(Wherein, R f 3 and R f 4 are the same or different and are an alkyl group of 1 to 10 carbon atoms or a fluorinated alkyl group of 1 to 10 carbon atoms, provided that at least one of R f 3 and R f 4 is fluorine Alkylated groups))
And fluorinated ethers (I) represented by By containing the fluorinated ether (I), the flame retardancy of the electrolytic solution is improved, and the stability at high temperature and high voltage and the safety are improved.
上記一般式（Ｉ）においては、Ｒｆ３及びＲｆ４の少なくとも一方が炭素数１～１０のフッ素化アルキル基であればよいが、電解液の難燃性及び高温高電圧での安定性、安全性を一層向上させる観点から、Ｒｆ３及びＲｆ４が、ともに炭素数１～１０のフッ素化アルキル基であることが好ましい。この場合、Ｒｆ３及びＲｆ４は同じであってもよく、互いに異なっていてもよい。
なかでも、Ｒｆ３及びＲｆ４が、同じか又は異なり、Ｒｆ３が炭素数３～６のフッ素化アルキル基であり、かつ、Ｒｆ４が炭素数２～６のフッ素化アルキル基であることがより好ましい。 In the above general formula (I), at least one of Rf 3 and Rf 4 may be a fluorinated alkyl group having 1 to 10 carbon atoms, but the flame retardancy of the electrolytic solution, stability at high temperature and high voltage, safety From the viewpoint of further improving the properties, it is preferable that both Rf 3 and Rf 4 be a fluorinated alkyl group having 1 to 10 carbon atoms. In this case, Rf 3 and Rf 4 may be the same or may be different from each other.
Among them, Rf 3 and Rf 4 are the same or different, and Rf 3 is a fluorinated alkyl group having 3 to 6 carbon atoms, and Rf 4 is a fluorinated alkyl group having 2 to 6 carbon atoms More preferable.
Ｒｆ３及びＲｆ４の合計炭素数が少な過ぎるとフッ素化エーテルの沸点が低くなりすぎ、また、Ｒｆ３又はＲｆ４の炭素数が多過ぎると、電解質塩の溶解性が低下し、他の溶媒との相溶性にも悪影響が出始め、また粘度が上昇するためレート特性が低減する。Ｒｆ３の炭素数が３又は４、Ｒｆ４の炭素数が２又は３のとき、沸点及びレート特性に優れる点で有利である。 If the total carbon number of Rf 3 and Rf 4 is too small, the boiling point of the fluorinated ether becomes too low, and if the carbon number of Rf 3 or Rf 4 is too large, the solubility of the electrolyte salt decreases and other solvents The compatibility with the compound also begins to be adversely affected, and the rate characteristic decreases because the viscosity increases. When the carbon number of Rf 3 is 3 or 4, and the carbon number of Rf 4 is 2 or 3, it is advantageous in that the boiling point and rate characteristics are excellent.
上記フッ素化エーテル（Ｉ）は、フッ素含有率が４０～７５質量％であることが好ましい。この範囲のフッ素含有率を有するとき、不燃性と相溶性のバランスに特に優れたものになる。また、耐酸化性、安全性が良好な点からも好ましい。
上記フッ素含有率の下限は、４５質量％がより好ましく、５０質量％が更に好ましく、５５質量％が特に好ましい。上限は７０質量％がより好ましく、６６質量％が更に好ましい。
なお、フッ素化エーテル（Ｉ）のフッ素含有率は、フッ素化エーテル（Ｉ）の構造式に基づいて、｛（フッ素原子の個数×１９）／フッ素化エーテル（Ｉ）の分子量｝×１００（％）により算出した値である。 The fluorinated ether (I) preferably has a fluorine content of 40 to 75% by mass. When it has a fluorine content in this range, the balance between incombustibility and compatibility becomes particularly excellent. Moreover, it is preferable also from the point whose oxidation resistance and safety are favorable.
The lower limit of the fluorine content is more preferably 45% by mass, further preferably 50% by mass, and particularly preferably 55% by mass. The upper limit is more preferably 70% by mass, and still more preferably 66% by mass.
The fluorine content of the fluorinated ether (I) is {(number of fluorine atoms × 19) / molecular weight of fluorinated ether (I)} × 100 (%) based on the structural formula of fluorinated ether (I) It is a value calculated by
Ｒｆ３としては、例えば、ＣＦ３ＣＦ２ＣＨ２－、ＣＦ３ＣＦＨＣＦ２－、ＨＣＦ２ＣＦ２ＣＦ２－、ＨＣＦ２ＣＦ２ＣＨ２－、ＣＦ３ＣＦ２ＣＨ２ＣＨ２－、ＣＦ３ＣＦＨＣＦ２ＣＨ２－、ＨＣＦ２ＣＦ２ＣＦ２ＣＦ２－、ＨＣＦ２ＣＦ２ＣＦ２ＣＨ２－、ＨＣＦ２ＣＦ２ＣＨ２ＣＨ２－、ＨＣＦ２ＣＦ（ＣＦ３）ＣＨ２－等が挙げられる。また、Ｒｆ４としては、例えば、－ＣＨ２ＣＦ２ＣＦ３、－ＣＦ２ＣＦＨＣＦ３、－ＣＦ２ＣＦ２ＣＦ２Ｈ、－ＣＨ２ＣＦ２ＣＦ２Ｈ、－ＣＨ２ＣＨ２ＣＦ２ＣＦ３、－ＣＨ２ＣＦ２ＣＦＨＣＦ３、－ＣＦ２ＣＦ２ＣＦ２ＣＦ２Ｈ、－ＣＨ２ＣＦ２ＣＦ２ＣＦ２Ｈ、－ＣＨ２ＣＨ２ＣＦ２ＣＦ２Ｈ、－ＣＨ２ＣＦ（ＣＦ３）ＣＦ２Ｈ、－ＣＦ２ＣＦ２Ｈ、－ＣＨ２ＣＦ２Ｈ、－ＣＦ２ＣＨ３等が挙げられる。 The Rf 3, for example, CF 3 CF 2 CH 2 - , CF 3 CFHCF 2 -, HCF 2 CF 2 CF 2 -, HCF 2 CF 2 CH 2 -, CF 3 CF 2 CH 2 CH 2 -, CF 3 CFHCF 2 CH 2- , HCF 2 CF 2 CF 2 CF 2- , HCF 2 CF 2 CF 2 CH 2- , HCF 2 CF 2 CH 2 CH 2- , HCF 2 CF (CF 3 ) CH 2- and the like. As the Rf 4, for example, -CH 2 CF 2 CF 3, -CF 2 CFHCF 3, -CF 2 CF 2 CF 2 H, -CH 2 CF 2 CF 2 H, -CH 2 CH 2 CF 2 CF 3 , -CH 2 CF 2 CFHCF 3 , -CF 2 CF 2 CF 2 CF 2 H, -CH 2 CF 2 CF 2 CF 2 H, -CH 2 CH 2 CF 2 CF 2 H, -CH 2 CF (CF 3 ) Examples include CF 2 H, -CF 2 CF 2 H, -CH 2 CF 2 H, -CF 2 CH 3 and the like.
上記フッ素化エーテル（Ｉ）の具体例としては、例えばＨＣＦ２ＣＦ２ＣＨ２ＯＣＦ２ＣＦ２Ｈ、ＣＦ３ＣＦ２ＣＨ２ＯＣＦ２ＣＦ２Ｈ、ＨＣＦ２ＣＦ２ＣＨ２ＯＣＦ２ＣＦＨＣＦ３、ＣＦ３ＣＦ２ＣＨ２ＯＣＦ２ＣＦＨＣＦ３、Ｃ６Ｆ１３ＯＣＨ３、Ｃ６Ｆ１３ＯＣ２Ｈ５、Ｃ８Ｆ１７ＯＣＨ３、Ｃ８Ｆ１７ＯＣ２Ｈ５、ＣＦ３ＣＦＨＣＦ２ＣＨ（ＣＨ３）ＯＣＦ２ＣＦＨＣＦ３、ＨＣＦ２ＣＦ２ＯＣＨ（Ｃ２Ｈ５）２、ＨＣＦ２ＣＦ２ＯＣ４Ｈ９、ＨＣＦ２ＣＦ２ＯＣＨ２ＣＨ（Ｃ２Ｈ５）２、ＨＣＦ２ＣＦ２ＯＣＨ２ＣＨ（ＣＨ３）２等が挙げられる。 Specific examples of the fluorinated ether (I), for example HCF 2 CF 2 CH 2 OCF 2 CF 2 H, CF 3 CF 2 CH 2 OCF 2 CF 2 H, HCF 2 CF 2 CH 2 OCF 2 CFHCF 3, CF 3 CF 2 CH 2 OCF 2 CFHCF 3 , C 6 F 13 OCH 3 , C 6 F 13 OC 2 H 5 , C 8 F 17 OCH 3 , C 8 F 17 OC 2 H 5 , CF 3 CFHCF 2 CH (CH 3 ) OCF 2 CFHCF 3 , HCF 2 CF 2 OCH (C 2 H 5 ) 2 , HCF 2 CF 2 OC 4 H 9 , HCF 2 CF 2 OCH 2 CH (C 2 H 5 ) 2 , HCF 2 CF 2 OCH 2 CH (CH 3 ) 2 and the like.
なかでも、片末端又は両末端にＨＣＦ２－又はＣＦ３ＣＦＨ－を含むものが分極性に優れ、沸点の高いフッ素化エーテル（Ｉ）を与えることができる。フッ素化エーテル（Ｉ）の沸点は、６７～１２０℃であることが好ましい。より好ましくは８０℃以上、更に好ましくは９０℃以上である。 Among them, those containing HCF 2 -or CF 3 CFH- at one end or both ends are excellent in polarizability, and fluorinated ether (I) having a high boiling point can be provided. The boiling point of the fluorinated ether (I) is preferably 67 to 120 ° C. The temperature is more preferably 80 ° C. or more, still more preferably 90 ° C. or more.
このようなフッ素化エーテル（Ｉ）としては、例えば、ＣＦ３ＣＨ２ＯＣＦ２ＣＦＨＣＦ３、ＣＦ３ＣＦ２ＣＨ２ＯＣＦ２ＣＦＨＣＦ３、ＨＣＦ２ＣＦ２ＣＨ２ＯＣＦ２ＣＦＨＣＦ３、ＨＣＦ２ＣＦ２ＣＨ２ＯＣＨ２ＣＦ２ＣＦ２Ｈ、ＣＦ３ＣＦＨＣＦ２ＣＨ２ＯＣＦ２ＣＦＨＣＦ３、ＨＣＦ２ＣＦ２ＣＨ２ＯＣＦ２ＣＦ２Ｈ、ＣＦ３ＣＦ２ＣＨ２ＯＣＦ２ＣＦ２Ｈ等の１種又は２種以上が挙げられる。
なかでも、高沸点、他の溶媒との相溶性や電解質塩の溶解性が良好な点で有利なことから、ＨＣＦ２ＣＦ２ＣＨ２ＯＣＦ２ＣＦＨＣＦ３（沸点１０６℃）、ＣＦ３ＣＦ２ＣＨ２ＯＣＦ２ＣＦＨＣＦ３（沸点８２℃）、ＨＣＦ２ＣＦ２ＣＨ２ＯＣＦ２ＣＦ２Ｈ（沸点９２℃）及びＣＦ３ＣＦ２ＣＨ２ＯＣＦ２ＣＦ２Ｈ（沸点６８℃）からなる群より選択される少なくとも１種であることが好ましく、ＨＣＦ２ＣＦ２ＣＨ２ＯＣＦ２ＣＦＨＣＦ３（沸点１０６℃）及びＨＣＦ２ＣＦ２ＣＨ２ＯＣＦ２ＣＦ２Ｈ（沸点９２℃）からなる群より選択される少なくとも１種であることがより好ましい。 Such fluorinated ether (I), for example, CF 3 CH 2 OCF 2 CFHCF 3, CF 3 CF 2 CH 2 OCF 2 CFHCF 3, HCF 2 CF 2 CH 2 OCF 2 CFHCF 3, HCF 2 CF 2 CH 2 OCH 2 CF 2 CF 2 H, CF 3 CFHCF 2 CH 2 OCF 2 CFHCF 3 , HCF 2 CF 2 CH 2 OCF 2 CF 2 H, CF 3 CF 2 CH 2 OCF 2 CF 2 H, or the like The above is mentioned.
Among them, HCF 2 CF 2 CH 2 OCF 2 CFHCF 3 (boiling point 106 ° C.), CF 3 CF 2 CH, which is advantageous in that it has high boiling point, compatibility with other solvents and good solubility of electrolyte salt. 2 OCF 2 CFHCF 3 (boiling point 82 ° C.), HCF 2 CF 2 CH 2 OCF 2 CF 2 H (boiling point 92 ° C.) and CF 3 CF 2 CH 2 OCF 2 CF 2 H (boiling point 68 ° C.) HCF 2 CF 2 CH 2 OCF 2 CFHCF 3 (boiling point 106 ° C.) and HCF 2 CF 2 CH 2 OCF 2 CF 2 H (boiling point 92 ° C.) It is more preferable that it is 1 type.
炭素数３～６の環状エーテルとしては、１，２－ジオキサン、１，３－ジオキサン、２－メチル－１，３－ジオキサン、４－メチル－１，３－ジオキサン、１，４－ジオキサン、メタホルムアルデヒド、２－メチル－１，３－ジオキソラン、１，３－ジオキソラン、４－メチル－１，３－ジオキソラン、２－（トリフルオロエチル）ジオキソラン２，２，－ビス（トリフルオロメチル）－１，３－ジオキソラン等、及びこれらのフッ素化化合物が挙げられる。中でも、ジメトキシメタン、ジエトキシメタン、エトキシメトキシメタン、エチレングリコール－ｎ－プロピルエーテル、エチレングリコールジ－ｎ－ブチルエーテル、ジエチレングリコールジメチルエーテル、クラウンエーテルが、リチウムイオンへの溶媒和能力が高く、イオン解離度を向上させる点で好ましく、特に好ましくは、粘性が低く、高いイオン伝導度を与えることから、ジメトキシメタン、ジエトキシメタン、エトキシメトキシメタンである。 Examples of cyclic ethers having 3 to 6 carbon atoms include 1,2-dioxane, 1,3-dioxane, 2-methyl-1,3-dioxane, 4-methyl-1,3-dioxane, 1,4-dioxane, and meta. Formaldehyde, 2-methyl-1,3-dioxolane, 1,3-dioxolane, 4-methyl-1,3-dioxolane, 2- (trifluoroethyl) dioxolane 2,2-bis (trifluoromethyl) -1, 3-dioxolane and the like, and fluorinated compounds thereof. Among them, dimethoxymethane, diethoxymethane, ethoxymethoxymethane, ethylene glycol-n-propyl ether, ethylene glycol di-n-butyl ether, diethylene glycol dimethyl ether, and crown ether have high ability to solvate lithium ion, and the degree of ion dissociation Preferred from the viewpoint of improvement, and particularly preferred are dimethoxymethane, diethoxymethane and ethoxymethoxymethane because they have low viscosity and give high ion conductivity.
上記窒素含有化合物としては、ニトリル、含フッ素ニトリル、カルボン酸アミド、含フッ素カルボン酸アミド、スルホン酸アミド及び含フッ素スルホン酸アミド、アセトアミド、ホルムアミド等が挙げられる。また、１－メチル－２－ピロリジノン、１－メチル－２－ピペリドン、３－メチル－２－オキサジリジノン、１，３－ジメチル－２－イミダゾリジノン及びＮ－メチルスクシンイミド等も使用できる。ただし、上記一般式（１ａ）、（１ｂ）及び（１ｃ）で表されるニトリル化合物は上記窒素含有化合物に含めないものとする。 Examples of the nitrogen-containing compound include nitriles, fluorine-containing nitriles, carboxylic acid amides, fluorine-containing carboxylic acid amides, sulfonic acid amides, fluorine-containing sulfonic acid amides, acetamide, formamide and the like. In addition, 1-methyl-2-pyrrolidinone, 1-methyl-2-piperidone, 3-methyl-2-oxaziridinone, 1,3-dimethyl-2-imidazolidinone and N-methylsuccinimide can also be used. However, the nitrile compounds represented by the above general formulas (1a), (1b) and (1c) are not included in the above nitrogen-containing compound.
上記ホウ素含有化合物としては、例えば、トリメチルボレート、トリエチルボレート等のホウ酸エステル、ホウ酸エーテル、及び、ホウ酸アルキル等が挙げられる。 Examples of the boron-containing compound include borate esters such as trimethyl borate and triethyl borate, borate ethers, and alkyl borates.
上記有機ケイ素含有化合物としては、例えば、（ＣＨ３）４－Ｓｉ、（ＣＨ３）３－Ｓｉ－Ｓｉ（ＣＨ３）３、シリコンオイル等が挙げられる。 Examples of the organic silicon-containing compound include (CH 3 ) 4 -Si, (CH 3 ) 3 -Si-Si (CH 3 ) 3 , silicone oil and the like.
上記不燃（難燃）化剤としては、リン酸エステルやホスファゼン系化合物が挙げられる。上記リン酸エステルとしては、例えば、含フッ素アルキルリン酸エステル、非フッ素系アルキルリン酸エステル、アリールリン酸エステル等が挙げられる。なかでも、少量で不燃効果を発揮できる点で、含フッ素アルキルリン酸エステルであることが好ましい。 Examples of the non-combustible (flame-retardant) agent include phosphoric acid esters and phosphazene compounds. Examples of the phosphoric acid ester include fluorine-containing alkyl phosphoric acid esters, non-fluorinated alkyl phosphoric acid esters, and aryl phosphoric acid esters. Among them, fluorine-containing alkyl phosphates are preferable in that they can exhibit the non-combustible effect in a small amount.
上記ホスファゼン系化合物は例えば、メトキシペンタフルオロシクロトリホスファゼン、フェノキシペンタフルオロシクロトリホスファゼン、ジメチルアミノペンタフルオロシクロトリホスファゼン、ジエチルアミノペンタフルオロシクロトリホスファゼン、エトキシペンタフルオロシクロトリホスファゼン、エトキシヘプタフルオロシクロテトラホスファゼン等が挙げられる。 Examples of the phosphazene-based compounds include methoxypentafluorocyclotriphosphazene, phenoxypentafluorocyclotriphosphazene, dimethylaminopentafluorocyclotriphosphazene, diethylaminopentafluorocyclotriphosphazene, ethoxypentafluorocyclotriphosphazene, and ethoxyheptafluorocyclotetraphosphazene. Can be mentioned.
上記含フッ素アルキルリン酸エステルとしては、具体的には、特開平１１－２３３１４１号公報に記載された含フッ素ジアルキルリン酸エステル、特開平１１－２８３６６９号公報に記載された環状のアルキルリン酸エステル、又は、含フッ素トリアルキルリン酸エステル等が挙げられる。 Specific examples of the fluorine-containing alkyl phosphoric acid ester include fluorine-containing dialkyl phosphoric acid esters described in JP-A-11-233141, and cyclic alkyl phosphoric acid esters described in JP-A-11-283669. And / or fluorine-containing trialkyl phosphate esters and the like.
上記不燃（難燃）化剤としては、（ＣＨ３Ｏ）３Ｐ＝Ｏ、（ＣＦ３ＣＨ２Ｏ）３Ｐ＝Ｏ、（ＨＣＦ２ＣＨ２Ｏ）３Ｐ＝Ｏ、（ＣＦ３ＣＦ２ＣＨ２）３Ｐ＝Ｏ、（ＨＣＦ２ＣＦ２ＣＨ２）３Ｐ＝Ｏ等が好ましい。 As the incombustible (flame retardant) agents, (CH 3 O) 3 P = O, (CF 3 CH 2 O) 3 P = O, (HCF 2 CH 2 O) 3 P = O, (CF 3 CF 2 CH 2 ) 3 P = O, (HCF 2 CF 2 CH 2 ) 3 P = O and the like are preferable.
上記界面活性剤としては、カチオン性界面活性剤、アニオン性界面活性剤、非イオン性界面活性剤、両性界面活性剤のいずれでもよいが、サイクル特性、レート特性が良好となる点から、フッ素原子を含むものであることが好ましい。 The surfactant may be any of a cationic surfactant, an anionic surfactant, a nonionic surfactant, and an amphoteric surfactant, but from the viewpoint of favorable cycle characteristics and rate characteristics, a fluorine atom. Is preferable.
このようなフッ素原子を含む界面活性剤としては、例えば、下記式（３０）：
Ｒｆ５ＣＯＯ－Ｍ＋　　　　　（３０）
（式中、Ｒｆ５は炭素数３～１０のエーテル結合を含んでいてもよい含フッ素アルキル基；Ｍ＋はＬｉ＋、Ｎａ＋、Ｋ＋又はＮＨＲ’３ ＋（Ｒ’は同じか又は異なり、いずれもＨ又は炭素数が１～３のアルキル基）である）
で表される含フッ素カルボン酸塩や、下記式（４０）：
Ｒｆ６ＳＯ３ －Ｍ＋　　　　　（４０）
（式中、Ｒｆ６は炭素数３～１０のエーテル結合を含んでいてもよい含フッ素アルキル基；Ｍ＋はＬｉ＋、Ｎａ＋、Ｋ＋又はＮＨＲ’３ ＋（Ｒ’は同じか又は異なり、いずれもＨ又は炭素数が１～３のアルキル基）である）
で表される含フッ素スルホン酸塩等が好ましい。 Examples of such a surfactant containing a fluorine atom include the following formula (30):
Rf 5 COO - M + (30)
(Wherein R f 5 is a fluorine-containing alkyl group which may contain an ether bond of 3 to 10 carbon atoms; M + is Li + , Na + , K + or NHR ′ 3 + (R ′ is the same or different) , All are H or an alkyl group having 1 to 3 carbon atoms))
Or a fluorinated carboxylic acid salt represented by the following formula (40):
Rf 6 SO 3 - M + (40)
(Wherein, Rf 6 is a fluorine-containing alkyl group which may contain an ether bond of 3 to 10 carbon atoms; M + is Li + , Na + , K + or NHR ′ 3 + (R ′ is the same or different) , All are H or an alkyl group having 1 to 3 carbon atoms))
The fluorine-containing sulfonate represented by these etc. are preferable.
上記界面活性剤の含有量は、充放電サイクル特性を低下させずに電解液の表面張力を低下させることができる点から、電解液中０．０１～２質量％であることが好ましい。 The content of the surfactant is preferably 0.01 to 2% by mass in the electrolytic solution, from the viewpoint of being able to reduce the surface tension of the electrolytic solution without deteriorating the charge-discharge cycle characteristics.
上記高誘電化添加剤としては、例えば、スルホラン、メチルスルホラン、γ－ブチロラクトン、γ－バレロラクトン等が挙げられる。 Examples of the high dielectric additives include sulfolane, methylsulfolane, γ-butyrolactone, γ-valerolactone and the like.
上記サイクル特性及びレート特性改善剤としては、例えば、酢酸メチル、酢酸エチル、テトラヒドロフラン、１，４－ジオキサン等が挙げられる。 Examples of the above cycle characteristics and rate characteristics improver include methyl acetate, ethyl acetate, tetrahydrofuran, 1,4-dioxane and the like.
また、本発明の電解液は、更に高分子材料と組み合わせてゲル状（可塑化された）のゲル電解液としてもよい。 In addition, the electrolytic solution of the present invention may be further combined with a polymer material to form a gel (plasticized) gel electrolytic solution.
かかる高分子材料としては、従来公知のポリエチレンオキシドやポリプロピレンオキシド、それらの変性体（特開平８－２２２２７０号公報、特開２００２－１００４０５号公報）；ポリアクリレート系ポリマー、ポリアクリロニトリルや、ポリフッ化ビニリデン、フッ化ビニリデン－ヘキサフルオロプロピレン共重合体等のフッ素樹脂（特表平４－５０６７２６号公報、特表平８－５０７４０７号公報、特開平１０－２９４１３１号公報）；それらフッ素樹脂と炭化水素系樹脂との複合体（特開平１１－３５７６５号公報、特開平１１－８６６３０号公報）等が挙げられる。特には、ポリフッ化ビニリデン、フッ化ビニリデン－ヘキサフルオロプロピレン共重合体をゲル電解質用高分子材料として用いることが望ましい。 As such polymer materials, conventionally known polyethylene oxide and polypropylene oxide, modified products thereof (Japanese Patent Laid-Open Nos. 8-222270 and 2002-100405); polyacrylate polymers, polyacrylonitrile, polyvinylidene fluoride and the like And fluorine resins such as vinylidene fluoride-hexafluoropropylene copolymer (JP-A-4-506726, JP-A-8-507407, JP-A-10-294131); those fluororesins and hydrocarbon-based resins Composites with resins (JP-A-11-35765, JP-A-11-86630) and the like can be mentioned. In particular, it is desirable to use polyvinylidene fluoride or a vinylidene fluoride-hexafluoropropylene copolymer as the polymer material for gel electrolyte.
そのほか、本発明の電解液は、特願２００４－３０１９３４号明細書に記載されているイオン伝導性化合物も含んでいてもよい。 In addition, the electrolytic solution of the present invention may also contain the ion conductive compound described in Japanese Patent Application No. 2004-301934.
このイオン伝導性化合物は、式（１－１）：
Ａ－（Ｄ）－Ｂ　（１－１）
［式中、Ｄは式（２－１）：
－（Ｄ１）ｎ－（ＦＡＥ）ｍ－（ＡＥ）ｐ－（Ｙ）ｑ－　（２－１）
（式中、Ｄ１は、式（２ａ）： This ion conductive compound has the formula (1-1):
A- (D) -B (1-1)
[Wherein, D is the formula (2-1):
-(D1) n- (FAE) m- (AE) p- (Y) q- (2-1)
(Wherein, D1 is the formula (2a):
Figure JPOXMLDOC01-appb-C000086
Figure JPOXMLDOC01-appb-C000086
（式中、Ｒｆは架橋性官能基を有していてもよい含フッ素エーテル基；Ｒ１０はＲｆと主鎖を結合する基又は結合手）
で示される側鎖に含フッ素エーテル基を有するエーテル単位；
ＦＡＥは、式（２ｂ）： (Wherein, R f is a fluorine-containing ether group which may have a crosslinkable functional group; R 10 is a group or a bond which connects R f to the main chain)
An ether unit having a fluorinated ether group in the side chain represented by
The FAE is represented by the formula (2b):
Figure JPOXMLDOC01-appb-C000087
Figure JPOXMLDOC01-appb-C000087
（式中、Ｒｆａは水素原子、架橋性官能基を有していてもよいフッ素化アルキル基；Ｒ１１はＲｆａと主鎖を結合する基又は結合手）
で示される側鎖にフッ素化アルキル基を有するエーテル単位；
ＡＥは、式（２ｃ）： (Wherein, Rfa is a hydrogen atom, a fluorinated alkyl group which may have a crosslinkable functional group; R 11 is a group or a bond which connects Rfa to the main chain)
An ether unit having a fluorinated alkyl group in the side chain represented by
AE is the equation (2c):
Figure JPOXMLDOC01-appb-C000088
Figure JPOXMLDOC01-appb-C000088
（式中、Ｒ１３は水素原子、架橋性官能基を有していてもよいアルキル基、架橋性官能基を有していてもよい脂肪族環式炭化水素基又は架橋性官能基を有していてもよい芳香族炭化水素基；Ｒ１２はＲ１３と主鎖を結合する基又は結合手）
で示されるエーテル単位；
Ｙは、式（２ｄ－１）～（２ｄ－３）： (Wherein R 13 has a hydrogen atom, an alkyl group which may have a crosslinkable functional group, an aliphatic cyclic hydrocarbon group which may have a crosslinkable functional group, or a crosslinkable functional group Aromatic hydrocarbon group which may be substituted; R 12 is a group or a bond which connects R 13 to the main chain)
Ether unit indicated by
Y is any of the formulas (2d-1) to (2d-3):
Figure JPOXMLDOC01-appb-C000089
Figure JPOXMLDOC01-appb-C000089
の少なくとも１種を含む単位；
ｎは０～２００の整数；ｍは０～２００の整数；ｐは０～１００００の整数；ｑは１～１００の整数；ただしｎ＋ｍは０ではなく、Ｄ１、ＦＡＥ、ＡＥ及びＹの結合順序は特定されない）；
Ａ及びＢは同じか又は異なり、水素原子、フッ素原子及び／又は架橋性官能基を含んでいてもよいアルキル基、フッ素原子及び／又は架橋性官能基を含んでいてもよいフェニル基、－ＣＯＯＨ基、－ＯＲ（Ｒは水素原子又はフッ素原子及び／又は架橋性官能基を含んでいてもよいアルキル基）、エステル基又はカーボネート基（ただし、Ｄの末端が酸素原子の場合は－ＣＯＯＨ基、－ＯＲ、エステル基及びカーボネート基ではない）］
で表される側鎖に含フッ素基を有する非晶性含フッ素ポリエーテル化合物である。 A unit comprising at least one of
n is an integer of 0 to 200; m is an integer of 0 to 200; p is an integer of 0 to 10000; q is an integer of 1 to 100; however, n + m is not 0, and the bonding order of D1, FAE, AE and Y is Not identified);
A and B are the same or different, and are a hydrogen atom, a fluorine atom and / or an alkyl group which may contain a crosslinkable functional group, a fluorine atom and / or a phenyl group which may contain a crosslinkable functional group, -COOH Group, -OR (R is a hydrogen atom or a fluorine atom and / or an alkyl group which may contain a crosslinkable functional group), an ester group or a carbonate group (provided that the terminal of D is an oxygen atom, -COOH group, -OR, not ester group and carbonate group)]
It is an amorphous fluorine-containing polyether compound which has a fluorine-containing group in the side chain represented by
本発明の電解液は、スルホン系化合物を含んでもよい。スルホン系化合物としては、炭素数３～６の環状スルホン、及び炭素数２～６の鎖状スルホンが好ましい。１分子中のスルホニル基の数は、１又は２であることが好ましい。 The electrolytic solution of the present invention may contain a sulfone-based compound. As the sulfone-based compound, a cyclic sulfone having 3 to 6 carbon atoms and a chain sulfone having 2 to 6 carbon atoms are preferable. The number of sulfonyl groups in one molecule is preferably 1 or 2.
環状スルホンとしては、モノスルホン化合物であるトリメチレンスルホン類、テトラメチレンスルホン類、ヘキサメチレンスルホン類；ジスルホン化合物であるトリメチレンジスルホン類、テトラメチレンジスルホン類、ヘキサメチレンジスルホン類等が挙げられる。中でも誘電率と粘性の観点から、テトラメチレンスルホン類、テトラメチレンジスルホン類、ヘキサメチレンスルホン類、ヘキサメチレンジスルホン類がより好ましく、テトラメチレンスルホン類（スルホラン類）が特に好ましい。 Examples of cyclic sulfones include monosulfone compounds such as trimethylenesulfones, tetramethylenesulfones, hexamethylenesulfones, disulfone compounds such as trimethylenedisulfones, tetramethylenedisulfones, and hexamethylenedisulfones. Among them, tetramethylene sulfones, tetramethylene disulfones, hexamethylene sulfones and hexamethylene disulfones are more preferable, and tetramethylene sulfones (sulfolanes) are particularly preferable, from the viewpoint of dielectric constant and viscosity.
スルホラン類としては、スルホラン及び／又はスルホラン誘導体（以下、スルホランも含めて「スルホラン類」と略記する場合がある。）が好ましい。スルホラン誘導体としては、スルホラン環を構成する炭素原子上に結合した水素原子の１以上がフッ素原子やアルキル基で置換されたものが好ましい。 The sulfolanes are preferably sulfolanes and / or sulfolane derivatives (hereinafter sometimes abbreviated as “sulfolanes” including sulfolanes). As the sulfolane derivative, one in which at least one hydrogen atom bonded to a carbon atom constituting a sulfolane ring is substituted with a fluorine atom or an alkyl group is preferable.
中でも、２－メチルスルホラン、３－メチルスルホラン、２－フルオロスルホラン、３－フルオロスルホラン、２，２－ジフルオロスルホラン、２，３－ジフルオロスルホラン、２，４－ジフルオロスルホラン、２，５－ジフルオロスルホラン、３，４－ジフルオロスルホラン、２－フルオロ－３－メチルスルホラン、２－フルオロ－２－メチルスルホラン、３－フルオロ－３－メチルスルホラン、３－フルオロ－２－メチルスルホラン、４－フルオロ－３－メチルスルホラン、４－フルオロ－２－メチルスルホラン、５－フルオロ－３－メチルスルホラン、５－フルオロ－２－メチルスルホラン、２－フルオロメチルスルホラン、３－フルオロメチルスルホラン、２－ジフルオロメチルスルホラン、３－ジフルオロメチルスルホラン、２－トリフルオロメチルスルホラン、３－トリフルオロメチルスルホラン、２－フルオロ－３－（トリフルオロメチル）スルホラン、３－フルオロ－３－（トリフルオロメチル）スルホラン、４－フルオロ－３－（トリフルオロメチル）スルホラン、３－スルホレン、５－フルオロ－３－（トリフルオロメチル）スルホラン等がイオン伝導度が高く入出力が高い点で好ましい。 Among them, 2-methylsulfolane, 3-methylsulfolane, 2-fluorosulfolane, 3-fluorosulfolane, 2,2-difluorosulfolane, 2,3-difluorosulfolane, 2,4-difluorosulfolane, 2,5-difluorosulfolane, 3,4-Difluorosulfolane, 2-fluoro-3-methylsulfolane, 2-fluoro-2-methylsulfolane, 3-fluoro-3-methylsulfolane, 3-fluoro-2-methylsulfolane, 4-fluoro-3-methylsulfolane Sulfolane, 4-fluoro-2-methylsulfolane, 5-fluoro-3-methylsulfolane, 5-fluoro-2-methylsulfolane, 2-fluoromethylsulfolane, 3-fluoromethylsulfolane, 2-difluoromethylsulfolane, 3-difluoro Methyl sulfolane, 2- Trifluoromethyl sulfolane, 3-trifluoromethyl sulfolane, 2-fluoro-3- (trifluoromethyl) sulfolane, 3-fluoro-3- (trifluoromethyl) sulfolane, 4-fluoro-3- (trifluoromethyl) sulfolane 3-Sulfolene, 5-fluoro-3- (trifluoromethyl) sulfolane and the like are preferable in that they have high ion conductivity and high input and output.
また、鎖状スルホンとしては、ジメチルスルホン、エチルメチルスルホン、ジエチルスルホン、ｎ－プロピルメチルスルホン、ｎ－プロピルエチルスルホン、ジ－ｎ－プロピルスルホン、イソプロピルメチルスルホン、イソプロピルエチルスルホン、ジイソプロピルスルホン、ｎ－ブチルメチルスルホン、ｎ－ブチルエチルスルホン、ｔ－ブチルメチルスルホン、ｔ－ブチルエチルスルホン、モノフルオロメチルメチルスルホン、ジフルオロメチルメチルスルホン、トリフルオロメチルメチルスルホン、モノフルオロエチルメチルスルホン、ジフルオロエチルメチルスルホン、トリフルオロエチルメチルスルホン、ペンタフルオロエチルメチルスルホン、エチルモノフルオロメチルスルホン、エチルジフルオロメチルスルホン、エチルトリフルオロメチルスルホン、パーフルオロエチルメチルスルホン、エチルトリフルオロエチルスルホン、エチルペンタフルオロエチルスルホン、ジ（トリフルオロエチル）スルホン、パーフルオロジエチルスルホン、フルオロメチル－ｎ－プロピルスルホン、ジフルオロメチル－ｎ－プロピルスルホン、トリフルオロメチル－ｎ－プロピルスルホン、フルオロメチルイソプロピルスルホン、ジフルオロメチルイソプロピルスルホン、トリフルオロメチルイソプロピルスルホン、トリフルオロエチル－ｎ－プロピルスルホン、トリフルオロエチルイソプロピルスルホン、ペンタフルオロエチル－ｎ－プロピルスルホン、ペンタフルオロエチルイソプロピルスルホン、トリフルオロエチル－ｎ－ブチルスルホン、トリフルオロエチル－ｔ－ブチルスルホン、ペンタフルオロエチル－ｎ－ブチルスルホン、ペンタフルオロエチル－ｔ－ブチルスルホン等が挙げられる。 Moreover, as a chain sulfone, dimethyl sulfone, ethyl methyl sulfone, diethyl sulfone, n-propyl methyl sulfone, n-propyl ethyl sulfone, di-n-propyl sulfone, isopropyl methyl sulfone, isopropyl ethyl sulfone, diisopropyl sulfone, n- Butyl methyl sulfone, n-butyl ethyl sulfone, t-butyl methyl sulfone, t-butyl ethyl sulfone, monofluoromethyl methyl sulfone, difluoromethyl methyl sulfone, trifluoromethyl methyl sulfone, monofluoroethyl methyl sulfone, difluoroethyl methyl sulfone, Trifluoroethyl methyl sulfone, pentafluoroethyl methyl sulfone, ethyl monofluoromethyl sulfone, ethyl difluoromethyl sulfone, ethyl trif Omethyl sulfone, perfluoroethyl methyl sulfone, ethyl trifluoroethyl sulfone, ethyl pentafluoroethyl sulfone, di (trifluoroethyl) sulfone, perfluorodiethyl sulfone, fluoromethyl-n-propyl sulfone, difluoromethyl-n-propyl sulfone Trifluoromethyl-n-propyl sulfone, fluoromethyl isopropyl sulfone, difluoromethyl isopropyl sulfone, trifluoromethyl isopropyl sulfone, trifluoroethyl-n-propyl sulfone, trifluoroethyl isopropyl sulfone, pentafluoroethyl-n-propyl sulfone, Pentafluoroethyl isopropyl sulfone, trifluoroethyl-n-butyl sulfone, trifluoroethyl-t-butyl sulfone Emissions, pentafluoroethyl -n- butyl sulfone, pentafluoroethyl -t- butyl sulfone, and the like.
中でも、ジメチルスルホン、エチルメチルスルホン、ジエチルスルホン、ｎ－プロピルメチルスルホン、イソプロピルメチルスルホン、ｎ－ブチルメチルスルホン、ｔ－ブチルメチルスルホン、モノフルオロメチルメチルスルホン、ジフルオロメチルメチルスルホン、トリフルオロメチルメチルスルホン、モノフルオロエチルメチルスルホン、ジフルオロエチルメチルスルホン、トリフルオロエチルメチルスルホン、ペンタフルオロエチルメチルスルホン、エチルモノフルオロメチルスルホン、エチルジフルオロメチルスルホン、エチルトリフルオロメチルスルホン、エチルトリフルオロエチルスルホン、エチルペンタフルオロエチルスルホン、トリフルオロメチル－ｎ－プロピルスルホン、トリフルオロメチルイソプロピルスルホン、トリフルオロエチル－ｎ－ブチルスルホン、トリフルオロエチル－ｔ－ブチルスルホン、トリフルオロメチル－ｎ－ブチルスルホン、トリフルオロメチル－ｔ－ブチルスルホン等がイオン伝導度が高く入出力が高い点で好ましい。 Among them, dimethyl sulfone, ethyl methyl sulfone, diethyl sulfone, n-propyl methyl sulfone, isopropyl methyl sulfone, n-butyl methyl sulfone, t-butyl methyl sulfone, monofluoromethyl methyl sulfone, difluoromethyl methyl sulfone, trifluoromethyl methyl sulfone Monofluoroethyl methyl sulfone difluoroethyl methyl sulfone trifluoroethyl methyl sulfone pentafluoroethyl methyl sulfone ethyl monofluoromethyl sulfone ethyl difluoromethyl sulfone ethyl trifluoromethyl sulfone ethyl trifluoroethyl sulfone ethyl pentafluoro Ethyl sulfone, trifluoromethyl-n-propyl sulfone, trifluoromethyl isopropyl sulfone, tri Ruoroechiru -n- butyl sulfone, trifluoroethyl -t- butyl sulfone, trifluoromethyl -n- butyl sulfone, trifluoromethyl -t- butyl sulfone is preferred because a higher high output ionic conductivity.
スルホン系化合物の含有量は、特に制限されず、本発明の効果を著しく損なわない限り任意であるが、上記溶媒１００体積％中、通常０．３体積％以上、好ましくは０．５体積％以上、より好ましくは１体積％以上であり、また、通常４０体積％以下、好ましくは３５体積％以下、より好ましくは３０体積％以下である。スルホン系化合物の含有量が上記範囲内であれば、サイクル特性や保存特性等の耐久性の向上効果が得られやすく、また、非水系電解液の粘度を適切な範囲とし、電気伝導率の低下を回避することができ、非水系電解液二次電池の入出力特性や充放電レート特性を適正な範囲とすることができる。 The content of the sulfone-based compound is not particularly limited and is arbitrary unless the effects of the present invention are significantly impaired. However, the content is generally 0.3% by volume or more, preferably 0.5% by volume or more in 100% by volume of the solvent And more preferably 1% by volume or more, and usually 40% by volume or less, preferably 35% by volume or less, and more preferably 30% by volume or less. If the content of the sulfone-based compound is within the above range, the effect of improving the durability such as cycle characteristics and storage characteristics can be easily obtained, and the viscosity of the non-aqueous electrolyte solution can be made into an appropriate range to lower the electrical conductivity. Can be avoided, and the input / output characteristics and charge / discharge rate characteristics of the non-aqueous electrolytic solution secondary battery can be made in an appropriate range.
本開示の電解液は、出力特性向上の観点から、添加剤として、フルオロリン酸リチウム塩類（但し、ＬｉＰＦ６を除く）及びＳ＝Ｏ基を有するリチウム塩類からなる群より選択される少なくとも１種の化合物（７）を含むことも好ましい。
なお、添加剤として化合物（７）を使用する場合、上述した電解質塩としては、化合物（７）以外の化合物を使用することが好ましい。 The electrolytic solution of the present disclosure is at least one selected from the group consisting of lithium fluorophosphate salts (with the exception of LiPF 6 ) and lithium salts having an S 添加 O group as additives from the viewpoint of improving output characteristics. It is also preferable to include the compound (7) of
In addition, when using a compound (7) as an additive, it is preferable to use compounds other than a compound (7) as an electrolyte salt mentioned above.
上記フルオロリン酸リチウム塩類としては、モノフルオロリン酸リチウム（ＬｉＰＯ３Ｆ）、ジフルオロリン酸リチウム（ＬｉＰＯ２Ｆ２）等が挙げられる。
上記Ｓ＝Ｏ基を有するリチウム塩類としては、モノフルオロスルホン酸リチウム（ＦＳＯ３Ｌｉ）、メチル硫酸リチウム（ＣＨ３ＯＳＯ３Ｌｉ）、エチル硫酸リチウム（Ｃ２Ｈ５ＯＳＯ３Ｌｉ）、２，２，２－トリフルオロエチル硫酸リチウム等が挙げられる。
化合物（７）としては、中でも、ＬｉＰＯ２Ｆ２、ＦＳＯ３Ｌｉ、Ｃ２Ｈ５ＯＳＯ３Ｌｉが好ましい。 Examples of lithium fluorophosphate salts include lithium monofluorophosphate (LiPO 3 F), lithium difluorophosphate (LiPO 2 F 2 ), and the like.
As lithium salts having the above S = O group, lithium monofluorosulfonate (FSO 3 Li), lithium methyl sulfate (CH 3 OSO 3 Li), lithium ethyl sulfate (C 2 H 5 OSO 3 Li), 2, 2 And 2-trifluoroethyl lithium sulfate.
Among them, LiPO 2 F 2 , FSO 3 Li and C 2 H 5 OSO 3 Li are preferable as the compound (7).
化合物（７）の含有量は、上記電解液に対し、０．００１～２０質量％であることが好ましく、０．０１～１５質量％であることがより好ましく、０．１～１０質量％であることが更に好ましく、０．１～７質量％であることが特に好ましい。 The content of the compound (7) is preferably 0.001 to 20% by mass, more preferably 0.01 to 15% by mass, and further preferably 0.1 to 10% by mass, with respect to the electrolyte solution. It is more preferable that the content be 0.1 to 7% by mass.
本発明の電解液には必要に応じて、更に他の添加剤を配合してもよい。他の添加剤としては、例えば、金属酸化物、ガラス等が挙げられる。 Other additives may be added to the electrolytic solution of the present invention as required. Examples of other additives include metal oxides and glasses.
本発明の電解液は、フッ化水素（ＨＦ）の含有量が５～２００ｐｐｍであることが好ましい。ＨＦを含有することにより、上述した添加剤の被膜形成を促進させることができる。ＨＦの含有量が少なすぎると、負極上での被膜形成能力が下がり、電気化学デバイスの特性が低下する傾向がある。また、ＨＦ含有量が多すぎると、ＨＦの影響により電解液の耐酸化性が低下する傾向がある。本発明の電解液は、上記範囲のＨＦを含有しても、電気化学デバイスの高温保存性回復容量率を低下させることがない。
ＨＦの含有量は、１０ｐｐｍ以上がより好ましく、２０ｐｐｍ以上が更に好ましい。ＨＦの含有量はまた、１００ｐｐｍ以下がより好ましく、８０ｐｐｍ以下が更に好ましく、５０ｐｐｍ以下が特に好ましい。
ＨＦの含有量は、中和滴定法により測定することができる。 The content of hydrogen fluoride (HF) in the electrolytic solution of the present invention is preferably 5 to 200 ppm. By containing HF, film formation of the above-mentioned additive can be promoted. When the content of HF is too low, the film forming ability on the negative electrode tends to be reduced, and the characteristics of the electrochemical device tend to be deteriorated. In addition, when the HF content is too high, the oxidation resistance of the electrolytic solution tends to decrease due to the influence of HF. The electrolytic solution of the present invention does not lower the high temperature storability recovery capacity rate of the electrochemical device even if it contains HF in the above range.
As for content of HF, 10 ppm or more is more preferable, and 20 ppm or more is still more preferable. The content of HF is also preferably 100 ppm or less, more preferably 80 ppm or less, and particularly preferably 50 ppm or less.
The content of HF can be measured by neutralization titration.
本発明の電解液は、上述した成分を用いて、任意の方法で調製するとよい。 The electrolytic solution of the present invention may be prepared by any method using the components described above.
本発明の電解液は、例えば、リチウムイオン二次電池、リチウムイオンキャパシタ、ハイブリットキャパシタ、電気二重層キャパシタ等の電気化学デバイスに好適に適用することができる。以下、本発明の電解液を用いた非水系電解液電池について説明する。
上記非水系電解液電池は、公知の構造を採ることができ、典型的には、イオン（例えばリチウムイオン）を吸蔵・放出可能な正極及び正極と、上記本発明の電解液とを備える。このような本発明の電解液を備える電気化学デバイスもまた、本発明の一つである。 The electrolytic solution of the present invention can be suitably applied to electrochemical devices such as, for example, lithium ion secondary batteries, lithium ion capacitors, hybrid capacitors, and electric double layer capacitors. Hereinafter, a non-aqueous electrolytic solution battery using the electrolytic solution of the present invention will be described.
The non-aqueous electrolyte battery can have a known structure, and typically includes a positive electrode and a positive electrode capable of inserting and extracting ions (for example, lithium ions), and the electrolytic solution of the present invention. An electrochemical device comprising such an electrolytic solution of the present invention is also one of the present invention.
電気化学デバイスとしては、リチウムイオン二次電池、リチウムイオンキャパシタ、キャパシタ（ハイブリッドキャパシタ、電気二重層キャパシタ）、ラジカル電池、太陽電池（特に色素増感型太陽電池）、リチウムイオン一次電池、燃料電池、各種電気化学センサー、エレクトロクロミック素子、電気化学スイッチング素子、アルミニウム電解コンデンサ、タンタル電解コンデンサ等が挙げられ、リチウムイオン二次電池、リチウムイオンキャパシタ、電気二重層キャパシタが好適である。
上記電気化学デバイスを備えるモジュールも本発明の一つである。 Electrochemical devices include lithium ion secondary batteries, lithium ion capacitors, capacitors (hybrid capacitors, electric double layer capacitors), radical cells, solar cells (especially dye-sensitized solar cells), lithium ion primary cells, fuel cells, Various electrochemical sensors, electrochromic devices, electrochemical switching devices, aluminum electrolytic capacitors, tantalum electrolytic capacitors and the like can be mentioned, and lithium ion secondary batteries, lithium ion capacitors, electric double layer capacitors are preferable.
A module comprising the above-mentioned electrochemical device is also one of the present invention.
本発明はまた、本発明の電解液を備えるリチウムイオン二次電池でもある。
上記リチウムイオン二次電池は、正極、負極、及び、上述の電解液を備えることが好ましい。 The present invention is also a lithium ion secondary battery comprising the electrolytic solution of the present invention.
The lithium ion secondary battery preferably includes a positive electrode, a negative electrode, and the above-described electrolyte solution.
＜正極＞
正極は、正極活物質を含む正極活物質層と、集電体とから構成される。 <Positive electrode>
The positive electrode is composed of a positive electrode active material layer containing a positive electrode active material and a current collector.
上記正極活物質としては、電気化学的にリチウムイオンを吸蔵・放出可能なものであれば特に制限されないが、例えば、リチウム含有遷移金属複合酸化物、リチウム含有遷移金属リン酸化合物、硫化物、導電性高分子等が挙げられる。なかでも、正極活物質としては、リチウム含有遷移金属複合酸化物、リチウム含有遷移金属リン酸化合物が好ましく、特に、高電圧を産み出すリチウム含有遷移金属複合酸化物が好ましい。 The positive electrode active material is not particularly limited as long as it can electrochemically store and release lithium ions, but, for example, a lithium-containing transition metal complex oxide, a lithium-containing transition metal phosphate compound, a sulfide, a conductive material Polymers and the like. Among them, as the positive electrode active material, a lithium-containing transition metal complex oxide and a lithium-containing transition metal phosphate compound are preferable, and in particular, a lithium-containing transition metal complex oxide that produces high voltage is preferable.
リチウム含有遷移金属複合酸化物の遷移金属としてはＶ、Ｔｉ、Ｃｒ、Ｍｎ、Ｆｅ、Ｃｏ、Ｎｉ、Ｃｕ等が好ましく、具体例としては、ＬｉＣｏＯ２等のリチウム・コバルト複合酸化物、ＬｉＮｉＯ２等のリチウム・ニッケル複合酸化物、ＬｉＭｎＯ２、ＬｉＭｎ２Ｏ４、Ｌｉ２ＭｎＯ４等のリチウム・マンガン複合酸化物、これらのリチウム遷移金属複合酸化物の主体となる遷移金属原子の一部をＮａ、Ｋ、Ｂ、Ｆ、Ａｌ、Ｔｉ、Ｖ、Ｃｒ、Ｍｎ、Ｆｅ、Ｃｏ、Ｌｉ、Ｎｉ、Ｃｕ、Ｚｎ、Ｍｇ、Ｇａ、Ｚｒ、Ｓｉ、Ｎｂ、Ｍｏ、Ｓｎ、Ｗ等の他の元素で置換したもの等が挙げられる。置換されたものの具体例としては、例えば、ＬｉＮｉ０．５Ｍｎ０．５Ｏ２、ＬｉＮｉ０．８５Ｃｏ０．１０Ａｌ０．０５Ｏ２、ＬｉＮｉ０．５Ｃｏ０．２Ｍｎ０．３Ｏ２、ＬｉＮｉ０．６Ｃｏ０．２Ｍｎ０．２Ｏ２、ＬｉＮｉ０．３３Ｃｏ０．３３Ｍｎ０．３３Ｏ２、ＬｉＮｉ０．４５Ｃｏ０．１０Ａｌ０．４５Ｏ２、ＬｉＭｎ１．８Ａｌ０．２Ｏ４、ＬｉＭｎ１．５Ｎｉ０．５Ｏ４等が挙げられる。 As a transition metal of the lithium-containing transition metal complex oxide, V, Ti, Cr, Mn, Fe, Co, Ni, Cu, etc. are preferable. As a specific example, lithium cobalt complex oxide such as LiCoO 2 , LiNiO 2 etc. Lithium-manganese complex oxides such as LiMnO 2 , LiMn 2 O 4 , Li 2 MnO 4 and the like, and a part of the transition metal atoms as the main component of these lithium transition metal complex oxides, Na, Substitution with other elements such as K, B, F, Al, Ti, V, Cr, Mn, Fe, Co, Li, Ni, Cu, Zn, Mg, Ga, Zr, Si, Nb, Mo, Sn, W, etc. And the like. Specific examples of those substituted, for example, LiNi 0.5 Mn 0.5 O 2, LiNi 0.85 Co 0.10 Al 0.05 O 2, LiNi 0.5 Co 0.2 Mn 0.3 O 2, LiNi 0.6 Co 0.2 Mn 0.2 O 2, LiNi 0.33 Co 0.33 Mn 0.33 O 2, LiNi 0.45 Co 0.10 Al 0.45 O 2, LiMn 1. 8 Al 0.2 O 4 , LiMn 1.5 Ni 0.5 O 4 and the like can be mentioned.
なかでも、上記リチウム含有遷移金属複合酸化物としては、高電圧にした場合でもエネルギー密度が高いＬｉＭｎ１．５Ｎｉ０．５Ｏ４、ＬｉＮｉ０．５Ｃｏ０．２Ｍｎ０．３Ｏ２、ＬｉＮｉ０．６Ｃｏ０．２Ｍｎ０．２Ｏ２が好ましい。 Among them, as the lithium-containing transition metal complex oxide, LiMn 1.5 Ni 0.5 O 4 , LiNi 0.5 Co 0.2 Mn 0.3 O 2 , which have high energy density even at high voltage. LiNi 0.6 Co 0.2 Mn 0.2 O 2 is preferred.
リチウム含有遷移金属リン酸化合物の遷移金属としては、Ｖ、Ｔｉ、Ｃｒ、Ｍｎ、Ｆｅ、Ｃｏ、Ｎｉ、Ｃｕ等が好ましく、具体例としては、例えば、ＬｉＦｅＰＯ４、Ｌｉ３Ｆｅ２（ＰＯ４）３、ＬｉＦｅＰ２Ｏ７等のリン酸鉄類、ＬｉＣｏＰＯ４等のリン酸コバルト類、これらのリチウム遷移金属リン酸化合物の主体となる遷移金属原子の一部をＡｌ、Ｔｉ、Ｖ、Ｃｒ、Ｍｎ、Ｆｅ、Ｃｏ、Ｌｉ、Ｎｉ、Ｃｕ、Ｚｎ、Ｍｇ、Ｇａ、Ｚｒ、Ｎｂ、Ｓｉ等の他の元素で置換したもの等が挙げられる。 As a transition metal of the lithium-containing transition metal phosphate compound, V, Ti, Cr, Mn, Fe, Co, Ni, Cu and the like are preferable, and as a specific example, for example, LiFePO 4 , Li 3 Fe 2 (PO 4 ) 3 , iron phosphates such as LiFeP 2 O 7 , cobalt phosphates such as LiCoPO 4 , and a part of transition metal atoms which become main components of these lithium transition metal phosphate compounds Al, Ti, V, Cr, Mn What is substituted by other elements, such as Fe, Co, Li, Ni, Cu, Zn, Mg, Ga, Zr, Nb, Si, etc. are mentioned.
上記リチウム含有遷移金属複合酸化物としては、例えば、
式：ＬｉａＭｎ２－ｂＭ１ ｂＯ４（式中、０．９≦ａ；０≦ｂ≦１．５；Ｍ１はＦｅ、Ｃｏ、Ｎｉ、Ｃｕ、Ｚｎ、Ａｌ、Ｓｎ、Ｃｒ、Ｖ、Ｔｉ、Ｍｇ、Ｃａ、Ｓｒ、Ｂ、Ｇａ、Ｉｎ、Ｓｉ及びＧｅよりなる群から選ばれる少なくとも１種の金属）で表されるリチウム・マンガンスピネル複合酸化物、
式：ＬｉＮｉ１－ｃＭ２ ｃＯ２（式中、０≦ｃ≦０．５；Ｍ２はＦｅ、Ｃｏ、Ｍｎ、Ｃｕ、Ｚｎ、Ａｌ、Ｓｎ、Ｃｒ、Ｖ、Ｔｉ、Ｍｇ、Ｃａ、Ｓｒ、Ｂ、Ｇａ、Ｉｎ、Ｓｉ及びＧｅよりなる群から選ばれる少なくとも１種の金属）で表されるリチウム・ニッケル複合酸化物、又は、
式：ＬｉＣｏ１－ｄＭ３ ｄＯ２（式中、０≦ｄ≦０．５；Ｍ３はＦｅ、Ｎｉ、Ｍｎ、Ｃｕ、Ｚｎ、Ａｌ、Ｓｎ、Ｃｒ、Ｖ、Ｔｉ、Ｍｇ、Ｃａ、Ｓｒ、Ｂ、Ｇａ、Ｉｎ、Ｓｉ及びＧｅよりなる群から選ばれる少なくとも１種の金属）で表されるリチウム・コバルト複合酸化物が挙げられる。 Examples of the lithium-containing transition metal composite oxide include
Formula: Li a Mn 2-b M 1 b O 4 (wherein, 0.9 ≦ a; 0 ≦ b ≦ 1.5; M 1 is Fe, Co, Ni, Cu, Zn, Al, Sn, Cr, Lithium-manganese spinel composite oxide represented by at least one metal selected from the group consisting of V, Ti, Mg, Ca, Sr, B, Ga, In, Si and Ge)
Formula: LiNi 1-c M 2 c O 2 (wherein, 0 ≦ c ≦ 0.5; M 2 is Fe, Co, Mn, Cu, Zn, Al, Sn, Cr, V, Ti, Mg, Ca, A lithium-nickel complex oxide represented by at least one metal selected from the group consisting of Sr, B, Ga, In, Si and Ge, or
Formula: LiCo 1-d M 3 d O 2 (wherein 0 ≦ d ≦ 0.5; M 3 is Fe, Ni, Mn, Cu, Zn, Al, Sn, Cr, V, Ti, Mg, Ca, And lithium-cobalt composite oxide represented by at least one metal selected from the group consisting of Sr, B, Ga, In, Si and Ge).
なかでも、エネルギー密度が高く、高出力なリチウムイオン二次電池を提供できる点から、ＬｉＣｏＯ２、ＬｉＭｎＯ２、ＬｉＮｉＯ２、ＬｉＭｎ２Ｏ４、ＬｉＮｉ０．８Ｃｏ０．１５Ａｌ０．０５Ｏ２、又はＬｉＮｉ１／３Ｃｏ１／３Ｍｎ１／３Ｏ２が好ましい。 Among them, LiCoO 2 , LiMnO 2 , LiNiO 2 , LiMn 2 O 4 , LiNi 0.8 Co 0.15 Al 0.05 O 2 from the viewpoint of being able to provide a lithium ion secondary battery with high energy density and high output. Or LiNi 1/3 Co 1/3 Mn 1/3 O 2 is preferred.
その他の上記正極活物質として、ＬｉＦｅＰＯ４、ＬｉＮｉ０．８Ｃｏ０．２Ｏ２、Ｌｉ１．２Ｆｅ０．４Ｍｎ０．４Ｏ２、ＬｉＮｉ０．５Ｍｎ０．５Ｏ２、ＬｉＶ３Ｏ６等が挙げられる。 Other of the positive electrode active material, LiFePO 4, LiNi 0.8 Co 0.2 O 2, Li 1.2 Fe 0.4 Mn 0.4 O 2, LiNi 0.5 Mn 0.5 O 2, LiV 3 O 6 etc. may be mentioned.
硫化物としては、ＴｉＳ２やＭｏＳ２等の二次元層状構造をもつ化合物や、一般式ＭｅｘＭｏ６Ｓ８（ＭｅはＰｂ、Ａｇ、Ｃｕをはじめとする各種遷移金属）で表される強固な三次元骨格構造を有するシュブレル化合物等が挙げられる。また、硫黄単体やＬｉＳｘで表される有機リチウム硫化物等も挙げられる。 As a sulfide, a compound having a two-dimensional layered structure such as TiS 2 or MoS 2 or a strong compound represented by the general formula Me x Mo 6 S 8 (Me is various transition metals including Pb, Ag, and Cu) And Schbrel compounds having a three-dimensional framework structure. In addition, elemental sulfur and organic lithium sulfides represented by LiS x and the like can also be mentioned.
導電性高分子としては、ｐ－ドーピング型の導電性高分子やｎ－ドーピング型の導電性高分子が挙げられる。導電性高分子としては、ポリアセチレン系、ポリフェニレン系、複素環ポリマー、イオン性ポリマー、ラダー及びネットワーク状ポリマー等が挙げられる。 Examples of the conductive polymer include p-doped conductive polymers and n-doped conductive polymers. Examples of the conductive polymer include polyacetylene-based, polyphenylene-based, heterocyclic polymers, ionic polymers, ladders and network polymers.
また、正極活物質にリン酸リチウムを含ませると、連続充電特性が向上するので好ましい。リン酸リチウムの使用に制限はないが、前記の正極活物質とリン酸リチウムを混合して用いることが好ましい。使用するリン酸リチウムの量は上記正極活物質とリン酸リチウムの合計に対し、下限が、好ましくは０．１質量％以上、より好ましくは０．３質量％以上、更に好ましくは０．５質量％以上であり、上限が、好ましくは１０質量％以下、より好ましくは８質量％以下、更に好ましくは５質量％以下である。 In addition, it is preferable to contain lithium phosphate in the positive electrode active material because continuous charge characteristics are improved. Although there is no restriction | limiting in use of lithium phosphate, It is preferable to mix and use said positive electrode active material and lithium phosphate. The lower limit of the amount of lithium phosphate used is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, and still more preferably 0.5% by mass, based on the total of the positive electrode active material and lithium phosphate. %, And the upper limit is preferably 10% by mass or less, more preferably 8% by mass or less, and still more preferably 5% by mass or less.
また、上記正極活物質の表面に、これとは異なる組成の物質が付着したものを用いてもよい。表面付着物質としては酸化アルミニウム、酸化ケイ素、酸化チタン、酸化ジルコニウム、酸化マグネシウム、酸化カルシウム、酸化ホウ素、酸化アンチモン、酸化ビスマス等の酸化物、硫酸リチウム、硫酸ナトリウム、硫酸カリウム、硫酸マグネシウム、硫酸カルシウム、硫酸アルミニウム等の硫酸塩、炭酸リチウム、炭酸カルシウム、炭酸マグネシウム等の炭酸塩、炭素等が挙げられる。 Moreover, you may use the thing in which the substance of the composition different from this adhered on the surface of the said positive electrode active material. As surface adhesion substances, aluminum oxide, silicon oxide, titanium oxide, zirconium oxide, magnesium oxide, calcium oxide, boron oxide, antimony oxide, oxides such as bismuth oxide, lithium sulfate, sodium sulfate, potassium sulfate, magnesium sulfate, calcium sulfate And sulfates such as aluminum sulfate, carbonates such as lithium carbonate, calcium carbonate and magnesium carbonate, and carbon.
これら表面付着物質は、例えば、溶媒に溶解又は懸濁させて該正極活物質に含浸添加、乾燥する方法、表面付着物質前駆体を溶媒に溶解又は懸濁させて該正極活物質に含浸添加後、加熱等により反応させる方法、正極活物質前駆体に添加して同時に焼成する方法等により該正極活物質表面に付着させることができる。なお、炭素を付着させる場合には、炭素質を、例えば、活性炭等の形で後から機械的に付着させる方法も用いることもできる。 These surface adhesion substances are, for example, dissolved or suspended in a solvent and impregnated and added to the positive electrode active material and dried, or the surface adhesion substance precursor is dissolved or suspended in a solvent and impregnated into the positive electrode active material It can be made to adhere to the surface of the positive electrode active material by a method of reacting by heating or the like, a method of adding it to the positive electrode active material precursor and simultaneously baking it. In addition, when making carbon adhere, the method of making carbon quality adhere mechanically later, for example, in the form of activated carbon etc. can also be used.
表面付着物質の量としては、上記正極活物質に対して質量で、下限として好ましくは０．１ｐｐｍ以上、より好ましくは１ｐｐｍ以上、更に好ましくは１０ｐｐｍ以上、上限として、好ましくは２０％以下、より好ましくは１０％以下、更に好ましくは５％以下で用いられる。表面付着物質により、正極活物質表面での電解液の酸化反応を抑制することができ、電池寿命を向上させることができるが、その付着量が少なすぎる場合その効果は十分に発現せず、多すぎる場合には、リチウムイオンの出入りを阻害するため抵抗が増加する場合がある。 The amount of the surface adhesion substance is preferably 0.1 ppm or more, more preferably 1 ppm or more, still more preferably 10 ppm or more, and preferably 20% or less as an upper limit, based on the mass of the positive electrode active material. Is used at 10% or less, more preferably 5% or less. The surface adhesion substance can suppress the oxidation reaction of the electrolytic solution on the surface of the positive electrode active material, and the battery life can be improved. However, when the adhesion amount is too small, the effect is not sufficiently expressed. If it is too high, the resistance may increase to inhibit the lithium ion ingress and egress.
正極活物質の粒子の形状は、従来用いられるような、塊状、多面体状、球状、楕円球状、板状、針状、柱状等が挙げられる。また、一次粒子が凝集して、二次粒子を形成していてもよい。 The shape of the particles of the positive electrode active material may, for example, be a block, a polyhedron, a sphere, an oval sphere, a plate, a needle, or a column as conventionally used. In addition, primary particles may be aggregated to form secondary particles.
正極活物質のタップ密度は、好ましくは０．５ｇ／ｃｍ３以上、より好ましくは０．８ｇ／ｃｍ３以上、更に好ましくは１．０ｇ／ｃｍ３以上である。該正極活物質のタップ密度が上記下限を下回ると正極活物質層形成時に、必要な分散媒量が増加すると共に、導電材や結着剤の必要量が増加し、正極活物質層への正極活物質の充填率が制約され、電池容量が制約される場合がある。タップ密度の高い複合酸化物粉体を用いることにより、高密度の正極活物質層を形成することができる。タップ密度は一般に大きいほど好ましく、特に上限はないが、大きすぎると、正極活物質層内における電解液を媒体としたリチウムイオンの拡散が律速となり、負荷特性が低下しやすくなる場合があるため、上限は、好ましくは４．０ｇ／ｃｍ３以下、より好ましくは３．７ｇ／ｃｍ３以下、更に好ましくは３．５ｇ／ｃｍ３以下である。
なお、本発明では、タップ密度は、正極活物質粉体５～１０ｇを１０ｍｌのガラス製メスシリンダーに入れ、ストローク約２０ｍｍで２００回タップした時の粉体充填密度（タップ密度）ｇ／ｃｍ３として求める。 The tap density of the positive electrode active material is preferably 0.5 g / cm 3 or more, more preferably 0.8 g / cm 3 or more, and still more preferably 1.0 g / cm 3 or more. When the tap density of the positive electrode active material is below the above lower limit, the necessary amount of dispersion medium increases at the time of forming the positive electrode active material layer, and the required amount of the conductive material and the binder increases, and the positive electrode to the positive electrode active material layer The filling rate of the active material may be limited, and the battery capacity may be limited. By using a composite oxide powder with a high tap density, a high density positive electrode active material layer can be formed. Generally, the tap density is preferably as high as possible, and there is no particular upper limit. However, if it is too large, diffusion of lithium ions in the positive electrode active material layer through the electrolyte may be limited, and load characteristics may be easily degraded. The upper limit is preferably 4.0 g / cm 3 or less, more preferably 3.7 g / cm 3 or less, and still more preferably 3.5 g / cm 3 or less.
In the present invention, the tap density is determined by placing 5 to 10 g of the positive electrode active material powder in a 10 ml glass measuring cylinder and tapping the powder packing density (tap density) g / cm 3 when tapping 200 times with a stroke of about 20 mm. Ask as.
正極活物質の粒子のメジアン径ｄ５０（一次粒子が凝集して二次粒子を形成している場合には二次粒子径）は好ましくは０．３μｍ以上、より好ましくは０．５μｍ以上、更に好ましくは０．８μｍ以上、最も好ましくは１．０μｍ以上であり、また、好ましくは３０μｍ以下、より好ましくは２７μｍ以下、更に好ましくは２５μｍ以下、最も好ましくは２２μｍ以下である。上記下限を下回ると、高タップ密度品が得られなくなる場合があり、上限を超えると粒子内のリチウムの拡散に時間がかかるため、電池性能の低下をきたしたり、電池の正極作成、即ち活物質と導電材やバインダー等を溶媒でスラリー化し、薄膜状に塗布する際に、スジを引く等の問題を生ずる場合がある。ここで、異なるメジアン径ｄ５０をもつ上記正極活物質を２種類以上混合することで、正極作成時の充填性を更に向上させることができる。 The median diameter d50 of the particles of the positive electrode active material (secondary particle diameter when primary particles are aggregated to form secondary particles) is preferably 0.3 μm or more, more preferably 0.5 μm or more, still more preferably Is preferably 0.8 μm or more, most preferably 1.0 μm or more, preferably 30 μm or less, more preferably 27 μm or less, still more preferably 25 μm or less, most preferably 22 μm or less. Below the lower limit, high tap density products may not be obtained. When the upper limit is exceeded, it takes time to diffuse lithium in the particles, resulting in deterioration of the battery performance or preparation of the positive electrode of the battery, ie active material When a conductive material, a binder or the like is slurried with a solvent and applied in a thin film, problems such as streaking may occur. Here, by mixing two or more types of the above-described positive electrode active materials having different median diameters d50, the filling property at the time of preparation of the positive electrode can be further improved.
なお、本発明では、メジアン径ｄ５０は、公知のレーザー回折／散乱式粒度分布測定装置によって測定される。粒度分布計としてＨＯＲＩＢＡ社製ＬＡ－９２０を用いる場合、測定の際に用いる分散媒として、０．１質量％ヘキサメタリン酸ナトリウム水溶液を用い、５分間の超音波分散後に測定屈折率１．２４を設定して測定される。 In the present invention, the median diameter d50 is measured by a known laser diffraction / scattering type particle size distribution measuring apparatus. When LA-920 manufactured by HORIBA is used as a particle size distribution analyzer, a 0.1 mass% sodium hexametaphosphate aqueous solution is used as a dispersion medium for measurement, and a refractive index of 1.24 is set after ultrasonic dispersion for 5 minutes. Measured.
一次粒子が凝集して二次粒子を形成している場合には、上記正極活物質の平均一次粒子径としては、好ましくは０．０５μｍ以上、より好ましくは０．１μｍ以上、更に好ましくは０．２μｍ以上であり、上限は、好ましくは５μｍ以下、より好ましくは４μｍ以下、更に好ましくは３μｍ以下、最も好ましくは２μｍ以下である。上記上限を超えると球状の二次粒子を形成し難く、粉体充填性に悪影響を及ぼしたり、比表面積が大きく低下するために、出力特性等の電池性能が低下する可能性が高くなる場合がある。逆に、上記下限を下回ると、通常、結晶が未発達であるために充放電の可逆性が劣る等の問題を生ずる場合がある。 When primary particles are aggregated to form secondary particles, the average primary particle diameter of the positive electrode active material is preferably 0.05 μm or more, more preferably 0.1 μm or more, and still more preferably 0. The upper limit is preferably 5 μm or less, more preferably 4 μm or less, still more preferably 3 μm or less, and most preferably 2 μm or less. If the above upper limit is exceeded, it is difficult to form spherical secondary particles, which adversely affects the powder packing property or significantly lowers the specific surface area, which may increase the possibility that battery performance such as output characteristics may be degraded. is there. On the other hand, if the lower limit is exceeded, usually problems such as poor reversibility of charge and discharge may occur due to underdeveloped crystals.
なお、本発明では、一次粒子径は、走査電子顕微鏡（ＳＥＭ）を用いた観察により測定される。具体的には、１００００倍の倍率の写真で、水平方向の直線に対する一次粒子の左右の境界線による切片の最長の値を、任意の５０個の一次粒子について求め、平均値をとることにより求められる。 In the present invention, the primary particle diameter is measured by observation using a scanning electron microscope (SEM). Specifically, in a photograph at a magnification of 10000, the longest value of the intercept by the left and right boundary lines of the primary particle with respect to the straight line in the horizontal direction is obtained for any 50 primary particles, and the average value is obtained Be
正極活物質のＢＥＴ比表面積は、好ましくは０．１ｍ２／ｇ以上、より好ましくは０．２ｍ２／ｇ以上、更に好ましくは０．３ｍ２／ｇ以上であり、上限は好ましくは５０ｍ２／ｇ以下、より好ましくは４０ｍ２／ｇ以下、更に好ましくは３０ｍ２／ｇ以下である。ＢＥＴ比表面積がこの範囲よりも小さいと電池性能が低下しやすく、大きいとタップ密度が上がりにくくなり、正極活物質層形成時の塗布性に問題が発生しやすい場合がある。 BET specific surface area of the positive electrode active material is preferably 0.1 m 2 / g or more, more preferably 0.2 m 2 / g or more, further preferably 0.3 m 2 / g or more, and the upper limit is preferably 50 m 2 / It is not more than g, more preferably not more than 40 m 2 / g, still more preferably not more than 30 m 2 / g. If the BET specific surface area is smaller than this range, the battery performance tends to be deteriorated, and if the BET specific surface area is large, it is difficult to increase the tap density, and a problem may easily occur in the coatability when forming the positive electrode active material layer.
なお、本発明では、ＢＥＴ比表面積は、表面積計（例えば、大倉理研社製全自動表面積測定装置）を用い、試料に対して窒素流通下１５０℃で３０分間、予備乾燥を行なった後、大気圧に対する窒素の相対圧の値が０．３となるように正確に調整した窒素ヘリウム混合ガスを用い、ガス流動法による窒素吸着ＢＥＴ１点法によって測定した値で定義される。 In the present invention, the BET specific surface area is determined by using a surface area meter (for example, a fully automatic surface area measuring device manufactured by Okura Riken Co., Ltd.) and predrying the sample for 30 minutes at 150 ° C. under nitrogen flow. It is defined as a value measured by a nitrogen adsorption BET one-point method by a gas flow method using a nitrogen-helium mixed gas which is accurately adjusted so that the value of the relative pressure of nitrogen to the atmospheric pressure is 0.3.
本発明のリチウムイオン二次電池が、ハイブリッド自動車用や分散電源用の大型リチウムイオン二次電池として使用される場合、高出力が要求されるため、上記正極活物質の粒子は二次粒子が主体となることが好ましい。
上記正極活物質の粒子は、二次粒子の平均粒子径が４０μｍ以下で、かつ、平均一次粒子径が１μｍ以下の微粒子を、０．５～７．０体積％含むものであることが好ましい。平均一次粒子径が１μｍ以下の微粒子を含有させることにより、電解液との接触面積が大きくなり、電極と電解液との間でのリチウムイオンの拡散をより速くすることができ、その結果、電池の出力性能を向上させることができる。 When the lithium ion secondary battery of the present invention is used as a large-sized lithium ion secondary battery for hybrid vehicles and dispersed power sources, high power is required, so the particles of the positive electrode active material are mainly secondary particles. It is preferable that
The particles of the positive electrode active material preferably contain 0.5 to 7.0% by volume of fine particles having an average particle diameter of secondary particles of 40 μm or less and an average primary particle diameter of 1 μm or less. By including fine particles having an average primary particle diameter of 1 μm or less, the contact area with the electrolytic solution becomes large, and the diffusion of lithium ions between the electrode and the electrolytic solution can be made faster, as a result, the battery Output performance can be improved.
正極活物質の製造法としては、無機化合物の製造法として一般的な方法が用いられる。特に球状ないし楕円球状の活物質を作成するには種々の方法が考えられるが、例えば、遷移金属の原料物質を水等の溶媒中に溶解ないし粉砕分散して、攪拌をしながらｐＨを調節して球状の前駆体を作成回収し、これを必要に応じて乾燥した後、ＬｉＯＨ、Ｌｉ２ＣＯ３、ＬｉＮＯ３等のＬｉ源を加えて高温で焼成して活物質を得る方法等が挙げられる。 As a manufacturing method of a positive electrode active material, a general method is used as a manufacturing method of an inorganic compound. In particular, various methods can be considered to form spherical or elliptical spherical active materials. For example, a transition metal source material is dissolved or pulverized in a solvent such as water, and the pH is adjusted while stirring. Spherical precursor is collected and dried, if necessary, added with a Li source such as LiOH, Li 2 CO 3 or LiNO 3 and calcined at high temperature to obtain an active material. .
正極の製造のために、前記の正極活物質を単独で用いてもよく、異なる組成の２種以上を、任意の組み合わせ又は比率で併用してもよい。この場合の好ましい組み合わせとしては、ＬｉＣｏＯ２とＬｉＮｉ０．３３Ｃｏ０．３３Ｍｎ０．３３Ｏ２等のＬｉＭｎ２Ｏ４若しくはこのＭｎの一部を他の遷移金属等で置換したものとの組み合わせ、あるいは、ＬｉＣｏＯ２若しくはこのＣｏの一部を他の遷移金属等で置換したものとの組み合わせが挙げられる。 For the production of the positive electrode, the above-mentioned positive electrode active material may be used alone, or two or more of different compositions may be used in any combination or ratio. As a preferable combination in this case, a combination of LiCoO 2 and LiMn 2 O 4 such as LiNi 0.33 Co 0.33 Mn 0.33 O 2 or a part of this Mn substituted with another transition metal etc. Or a combination of LiCoO 2 or a part of this Co substituted with another transition metal or the like.
上記正極活物質の含有量は、電池容量が高い点で、正極合剤の５０～９９．５質量％が好ましく、８０～９９質量％がより好ましい。また、正極活物質の、正極活物質層中の含有量は、好ましくは８０質量％以上、より好ましくは８２質量％以上、特に好ましくは８４質量％以上である。また上限は、好ましくは９９質量％以下、より好ましくは９８質量％以下である。正極活物質層中の正極活物質の含有量が低いと電気容量が不十分となる場合がある。逆に含有量が高すぎると正極の強度が不足する場合がある。 The content of the positive electrode active material is preferably 50 to 99.5% by mass, and more preferably 80 to 99% by mass, of the positive electrode mixture in view of high battery capacity. The content of the positive electrode active material in the positive electrode active material layer is preferably 80% by mass or more, more preferably 82% by mass or more, and particularly preferably 84% by mass or more. The upper limit is preferably 99% by mass or less, more preferably 98% by mass or less. If the content of the positive electrode active material in the positive electrode active material layer is low, the electrical capacity may be insufficient. Conversely, if the content is too high, the strength of the positive electrode may be insufficient.
上記正極合剤は、更に、結着剤、増粘剤、導電材を含むことが好ましい。
上記結着剤としては、電極製造時に使用する溶媒や電解液に対して安全な材料であれば、任意のものを使用することができ、例えば、ポリエチレン、ポリプロピレン、ポリエチレンテレフタレート、ポリメチルメタクリレート、芳香族ポリアミド、キトサン、アルギン酸、ポリアクリル酸、ポリイミド、セルロース、ニトロセルロース等の樹脂系高分子；ＳＢＲ（スチレン・ブタジエンゴム）、イソプレンゴム、ブタジエンゴム、フッ素ゴム、ＮＢＲ（アクリロニトリル・ブタジエンゴム）、エチレン・プロピレンゴム等のゴム状高分子；スチレン・ブタジエン・スチレンブロック共重合体又はその水素添加物；ＥＰＤＭ（エチレン・プロピレン・ジエン三元共重合体）、スチレン・エチレン・ブタジエン・スチレン共重合体、スチレン・イソプレン・スチレンブロック共重合体又はその水素添加物等の熱可塑性エラストマー状高分子；シンジオタクチック－１，２－ポリブタジエン、ポリ酢酸ビニル、エチレン・酢酸ビニル共重合体、プロピレン・α－オレフィン共重合体等の軟質樹脂状高分子；ポリフッ化ビニリデン、ポリテトラフルオロエチレン、フッ化ビニリデン共重合体、テトラフルオロエチレン・エチレン共重合体等のフッ素系高分子；アルカリ金属イオン（特にリチウムイオン）のイオン伝導性を有する高分子組成物等が挙げられる。これらは、１種を単独で用いても、２種以上を任意の組み合わせ及び比率で併用してもよい。 The positive electrode mixture preferably further contains a binder, a thickener, and a conductive material.
Any binder can be used as the binder as long as it is a material safe to the solvent and electrolyte used in the production of the electrode. For example, polyethylene, polypropylene, polyethylene terephthalate, polymethyl methacrylate, aroma -Based polymers such as chitosan, alginic acid, polyacrylic acid, polyimide, cellulose and nitrocellulose; SBR (styrene-butadiene rubber), isoprene rubber, butadiene rubber, fluororubber, NBR (acrylonitrile-butadiene rubber), ethylene・ Rubber-like polymers such as propylene rubber; styrene / butadiene / styrene block copolymer or hydrogenated product thereof; EPDM (ethylene / propylene / diene terpolymer), styrene / ethylene / butadiene / styrene copolymer, Styrene I Thermoplastic elastomeric polymers such as prene / styrene block copolymers or their hydrogenated products; syndiotactic-1,2-polybutadiene, polyvinyl acetate, ethylene / vinyl acetate copolymer, propylene / α-olefin copolymer Soft resinous polymers such as coalescing, etc .; fluorinated polymers such as polyvinylidene fluoride, polytetrafluoroethylene, vinylidene fluoride copolymers, tetrafluoroethylene / ethylene copolymers, etc .; ions of alkali metal ions (especially lithium ions) The polymer composition etc. which have conductivity are mentioned. One of these may be used alone, or two or more of these may be used in any combination and ratio.
結着剤の含有量は、正極活物質層中の結着剤の割合として、通常０．１質量％以上、好ましくは１質量％以上、更に好ましくは１．５質量％以上であり、また、通常８０質量％以下、好ましくは６０質量％以下、更に好ましくは４０質量％以下、最も好ましくは１０質量％以下である。結着剤の割合が低すぎると、正極活物質を十分保持できずに正極の機械的強度が不足し、サイクル特性等の電池性能を悪化させてしまう場合がある。一方で、高すぎると、電池容量や導電性の低下につながる場合がある。 The content of the binder is usually 0.1% by mass or more, preferably 1% by mass or more, more preferably 1.5% by mass or more, as a ratio of the binder in the positive electrode active material layer. Usually, it is 80% by mass or less, preferably 60% by mass or less, more preferably 40% by mass or less, and most preferably 10% by mass or less. If the proportion of the binder is too low, the positive electrode active material can not be sufficiently retained, and the mechanical strength of the positive electrode is insufficient, which may deteriorate battery performance such as cycle characteristics. On the other hand, if it is too high, it may lead to a decrease in battery capacity and conductivity.
上記増粘剤としては、カルボキシメチルセルロース、メチルセルロース、ヒドロキシメチルセルロース、エチルセルロース、ポリビニルアルコール、酸化スターチ、リン酸化スターチ、カゼイン、ポリビニルピロリドン及びこれらの塩等が挙げられる。１種を単独で用いても、２種以上を任意の組み合わせ及び比率で併用してもよい。 Examples of the thickener include carboxymethylcellulose, methylcellulose, hydroxymethylcellulose, ethylcellulose, polyvinyl alcohol, oxidized starch, phosphorylated starch, casein, polyvinyl pyrrolidone and salts thereof. One type may be used alone, or two or more types may be used in any combination and ratio.
活物質に対する増粘剤の割合は、通常０．１質量％以上、好ましくは０．２質量％以上、より好ましくは０．３質量％以上であり、また、通常５質量％以下、好ましくは３質量％以下、より好ましくは２質量％以下の範囲である。この範囲を下回ると、著しく塗布性が低下する場合がある。上回ると、正極活物質層に占める活物質の割合が低下し、電池の容量が低下する問題や正極活物質間の抵抗が増大する問題が生じる場合がある。 The ratio of the thickener to the active material is usually 0.1% by mass or more, preferably 0.2% by mass or more, more preferably 0.3% by mass or more, and usually 5% by mass or less, preferably 3 It is a range of not more than mass%, more preferably not more than 2 mass%. Below this range, the coatability may be significantly reduced. If it exceeds, the proportion of the active material in the positive electrode active material layer may be reduced, which may cause a problem of a decrease in battery capacity or an increase in resistance between the positive electrode active materials.
上記導電材としては、公知の導電材を任意に用いることができる。具体例としては、銅、ニッケル等の金属材料、天然黒鉛、人造黒鉛等の黒鉛（グラファイト）、アセチレンブラック、ケッチェンブラック、チャンネルブラック、ファーネスブラック、ランプブラック、サーマルブラック等のカーボンブラック、ニードルコークス、カーボンナノチューブ、フラーレン、ＶＧＣＦ等の無定形炭素等の炭素材料等が挙げられる。なお、これらは、１種を単独で用いてもよく、２種以上を任意の組み合わせ及び比率で併用してもよい。導電材は、正極活物質層中に、通常０．０１質量％以上、好ましくは０．１質量％以上、より好ましくは１質量％以上であり、また、通常５０質量％以下、好ましくは３０質量％以下、より好ましくは１５質量％以下含有するように用いられる。含有量がこの範囲よりも低いと導電性が不十分となる場合がある。逆に、含有量がこの範囲よりも高いと電池容量が低下する場合がある。 A well-known conductive material can be used arbitrarily as said conductive material. Specific examples include metal materials such as copper and nickel, graphite (natural graphite), graphite such as artificial graphite, acetylene black, ketjen black, channel black, furnace black, lamp black, carbon black such as thermal black, needle coke And carbon materials such as carbon nanotubes, fullerenes, amorphous carbon such as VGCF, and the like. In addition, these may be used individually by 1 type and may use 2 or more types together by arbitrary combinations and a ratio. The conductive material is usually 0.01% by mass or more, preferably 0.1% by mass or more, more preferably 1% by mass or more, and usually 50% by mass or less, preferably 30% by mass, in the positive electrode active material layer. % Or less, more preferably 15% by mass or less. If the content is lower than this range, the conductivity may be insufficient. Conversely, if the content is higher than this range, the battery capacity may decrease.
スラリーを形成するための溶媒としては、正極活物質、導電材、結着剤、並びに必要に応じて使用される増粘剤を溶解又は分散することが可能な溶媒であれば、その種類に特に制限はなく、水系溶媒と有機系溶媒のどちらを用いてもよい。水系溶媒としては、例えば、水、アルコールと水との混合媒等が挙げられる。有機系溶媒としては、例えば、ヘキサン等の脂肪族炭化水素類；ベンゼン、トルエン、キシレン、メチルナフタレン等の芳香族炭化水素類；キノリン、ピリジン等の複素環化合物；アセトン、メチルエチルケトン、シクロヘキサノン等のケトン類；酢酸メチル、アクリル酸メチル等のエステル類；ジエチレントリアミン、Ｎ，Ｎ－ジメチルアミノプロピルアミン等のアミン類；ジエチルエーテル、プロピレンオキシド、テトラヒドロフラン（ＴＨＦ）等のエーテル類；Ｎ－メチルピロリドン（ＮＭＰ）、ジメチルホルムアミド、ジメチルアセトアミド等のアミド類；ヘキサメチルホスファルアミド、ジメチルスルホキシド等の非プロトン性極性溶媒等が挙げられる。 As a solvent for forming a slurry, any solvent that can dissolve or disperse the positive electrode active material, the conductive material, the binder, and the thickener used as needed, is particularly selected as the solvent. There is no limitation, and either an aqueous solvent or an organic solvent may be used. Examples of the aqueous solvent include water and mixed solvents of alcohol and water. Examples of organic solvents include aliphatic hydrocarbons such as hexane; aromatic hydrocarbons such as benzene, toluene, xylene and methylnaphthalene; heterocyclic compounds such as quinoline and pyridine; ketones such as acetone, methyl ethyl ketone and cyclohexanone Esters such as methyl acetate and methyl acrylate; Amines such as diethylenetriamine and N, N-dimethylaminopropylamine; Ethers such as diethyl ether, propylene oxide and tetrahydrofuran (THF); N-methylpyrrolidone (NMP) And amides such as dimethylformamide and dimethylacetamide; and aprotic polar solvents such as hexamethylphosphaamide and dimethylsulfoxide.
正極用集電体の材質としては、アルミニウム、チタン、タンタル、ステンレス鋼、ニッケル等の金属、又は、その合金等の金属材料；カーボンクロス、カーボンペーパー等の炭素材料が挙げられる。なかでも、金属材料、特にアルミニウム又はその合金が好ましい。 Examples of the material of the current collector for the positive electrode include metals such as metals such as aluminum, titanium, tantalum, stainless steel and nickel, or alloys thereof; and carbon materials such as carbon cloth and carbon paper. Among them, metal materials, particularly aluminum or its alloy are preferable.
集電体の形状としては、金属材料の場合、金属箔、金属円柱、金属コイル、金属板、金属薄膜、エキスパンドメタル、パンチメタル、発泡メタル等が挙げられ、炭素材料の場合、炭素板、炭素薄膜、炭素円柱等が挙げられる。これらのうち、金属薄膜が好ましい。なお、薄膜は適宜メッシュ状に形成してもよい。薄膜の厚さは任意であるが、通常１μｍ以上、好ましくは３μｍ以上、より好ましくは５μｍ以上、また、通常１ｍｍ以下、好ましくは１００μｍ以下、より好ましくは５０μｍ以下である。薄膜がこの範囲よりも薄いと集電体として必要な強度が不足する場合がある。逆に、薄膜がこの範囲よりも厚いと取り扱い性が損なわれる場合がある。 Examples of the shape of the current collector include metal foils, metal cylinders, metal coils, metal coils, metal plates, metal thin films, expanded metals, punched metals, foamed metals and the like in the case of metal materials, and in the case of carbon materials, carbon plates and carbons A thin film, a carbon cylinder, etc. are mentioned. Of these, metal thin films are preferred. The thin film may be formed in a mesh shape as appropriate. The thickness of the thin film is arbitrary, but is usually 1 μm or more, preferably 3 μm or more, more preferably 5 μm or more, and usually 1 mm or less, preferably 100 μm or less, more preferably 50 μm or less. If the thin film is thinner than this range, the strength required for the current collector may be insufficient. Conversely, if the thin film is thicker than this range, the handleability may be impaired.
また、集電体の表面に導電助剤が塗布されていることも、集電体と正極活物質層の電気接触抵抗を低下させる観点で好ましい。導電助剤としては、炭素や、金、白金、銀等の貴金属類が挙げられる。 Moreover, it is also preferable that the conductive support agent is apply | coated to the surface of a collector from a viewpoint of reducing the electrical contact resistance of a collector and a positive electrode active material layer. Examples of the conductive aid include carbon, and noble metals such as gold, platinum and silver.
集電体と正極活物質層の厚さの比は特には限定されないが、（電解液注液直前の片面の正極活物質層の厚さ）／（集電体の厚さ）の値が２０以下であることが好ましく、より好ましくは１５以下、最も好ましくは１０以下であり、また、０．５以上が好ましく、より好ましくは０．８以上、最も好ましくは１以上の範囲である。この範囲を上回ると、高電流密度充放電時に集電体がジュール熱による発熱を生じる場合がある。この範囲を下回ると、正極活物質に対する集電体の体積比が増加し、電池の容量が減少する場合がある。 The ratio of the thickness of the current collector to the thickness of the positive electrode active material layer is not particularly limited, but the value of (thickness of positive electrode active material layer on one side immediately before electrolyte injection) / (thickness of current collector) is 20 It is preferably the following, more preferably 15 or less, most preferably 10 or less, and preferably 0.5 or more, more preferably 0.8 or more, and most preferably 1 or more. If this range is exceeded, the current collector may generate Joule heat during high current density charge and discharge. Below this range, the volume ratio of the current collector to the positive electrode active material may increase, and the capacity of the battery may decrease.
正極の製造は、常法によればよい。例えば、上記正極活物質に、上述した結着剤、増粘剤、導電材、溶媒等を加えてスラリー状の正極合剤とし、これを集電体に塗布し、乾燥した後にプレスして高密度化する方法が挙げられる。 The production of the positive electrode may be performed according to a conventional method. For example, the binder, thickener, conductive material, solvent and the like described above are added to the above-mentioned positive electrode active material to form a slurry-like positive electrode mixture, which is applied to a current collector, dried and pressed. There is a method of densifying.
上記高密度化は、ハンドプレス、ローラープレス等により行うことができる。正極活物質層の密度は、好ましくは１．５ｇ／ｃｍ３以上、より好ましくは２ｇ／ｃｍ３以上、更に好ましくは２．２ｇ／ｃｍ３以上であり、また、好ましくは５ｇ／ｃｍ３以下、より好ましくは４．５ｇ／ｃｍ３以下、更に好ましくは４ｇ／ｃｍ３以下の範囲である。この範囲を上回ると集電体／活物質界面付近への電解液の浸透性が低下し、特に高電流密度での充放電特性が低下し高出力が得られない場合がある。また下回ると活物質間の導電性が低下し、電池抵抗が増大し高出力が得られない場合がある。 The densification can be performed by a hand press, a roller press or the like. Density of the positive electrode active material layer is preferably 1.5 g / cm 3 or more, more preferably 2 g / cm 3 or more, still more preferably 2.2 g / cm 3 or more, preferably 5 g / cm 3 or less, More preferably, it is 4.5 g / cm 3 or less, further preferably 4 g / cm 3 or less. If this range is exceeded, the permeability of the electrolyte to the vicinity of the current collector / active material interface may be reduced, and in particular, the charge / discharge characteristics at high current densities may be reduced, and a high output may not be obtained. On the other hand, if it is lower than that, the conductivity between the active materials may be reduced, and the battery resistance may be increased to fail to obtain high output.
本発明の電解液を用いる場合、高出力かつ高温時の安定性を高める観点から、正極活物質層の面積は、電池外装ケースの外表面積に対して大きくすることが好ましい。具体的には、二次電池の外装の表面積に対する正極の電極面積の総和が面積比で１５倍以上とすることが好ましく、更に４０倍以上とすることがより好ましい。電池外装ケースの外表面積とは、有底角型形状の場合には、端子の突起部分を除いた発電要素が充填されたケース部分の縦と横と厚さの寸法から計算で求める総面積をいう。有底円筒形状の場合には、端子の突起部分を除いた発電要素が充填されたケース部分を円筒として近似する幾何表面積である。正極の電極面積の総和とは、負極活物質を含む合剤層に対向する正極合剤層の幾何表面積であり、集電体箔を介して両面に正極合剤層を形成してなる構造では、それぞれの面を別々に算出する面積の総和をいう。 When using the electrolytic solution of the present invention, it is preferable to make the area of the positive electrode active material layer larger than the outer surface area of the battery case from the viewpoint of enhancing the stability at high output and high temperature. Specifically, the sum of the electrode area of the positive electrode to the surface area of the exterior of the secondary battery is preferably 15 times or more in area ratio, and more preferably 40 times or more. The external surface area of the battery outer case is, in the case of a rectangular shape with a bottom, the total area obtained by calculation from the dimensions of the length, width, and thickness of the case portion filled with the power generation element excluding the protruding portion of the terminal. Say. In the case of a bottomed cylindrical shape, it is a geometric surface area which approximates the case part filled with the power generation element excluding the protruding part of the terminal as a cylinder. The sum of the electrode area of the positive electrode is the geometric surface area of the positive electrode mixture layer facing the mixture layer containing the negative electrode active material, and in the structure formed by forming the positive electrode mixture layer on both sides via the current collector foil. , The sum of the area to calculate each face separately.
正極板の厚さは特に限定されないが、高容量かつ高出力の観点から、芯材の金属箔厚さを差し引いた合剤層の厚さは、集電体の片面に対して下限として、好ましくは１０μｍ以上、より好ましくは２０μｍ以上で、また、好ましくは５００μｍ以下、より好ましくは４５０μｍ以下である。 The thickness of the positive electrode plate is not particularly limited, but from the viewpoint of high capacity and high output, the thickness of the mixture layer obtained by subtracting the metal foil thickness of the core material is preferably set as the lower limit to one side of the current collector. Is preferably 10 μm or more, more preferably 20 μm or more, and preferably 500 μm or less, more preferably 450 μm or less.
また、上記正極板の表面に、これとは異なる組成の物質が付着したものを用いてもよい。表面付着物質としては酸化アルミニウム、酸化ケイ素、酸化チタン、酸化ジルコニウム、酸化マグネシウム、酸化カルシウム、酸化ホウ素、酸化アンチモン、酸化ビスマス等の酸化物、硫酸リチウム、硫酸ナトリウム、硫酸カリウム、硫酸マグネシウム、硫酸カルシウム、硫酸アルミニウム等の硫酸塩、炭酸リチウム、炭酸カルシウム、炭酸マグネシウム等の炭酸塩、炭素等が挙げられる。 Moreover, you may use that to which the substance of the composition different from this adhered on the surface of the said positive electrode plate. As surface adhesion substances, aluminum oxide, silicon oxide, titanium oxide, zirconium oxide, magnesium oxide, calcium oxide, boron oxide, antimony oxide, oxides such as bismuth oxide, lithium sulfate, sodium sulfate, potassium sulfate, magnesium sulfate, calcium sulfate And sulfates such as aluminum sulfate, carbonates such as lithium carbonate, calcium carbonate and magnesium carbonate, and carbon.
＜負極＞
負極は、負極活物質を含む負極活物質層と、集電体とから構成される。 <Negative electrode>
The negative electrode is composed of a negative electrode active material layer containing a negative electrode active material, and a current collector.
負極材料としては、電気化学的にリチウムイオンを吸蔵・放出可能なものであれば、特に制限はない。具体例としては、炭素材料、合金系材料、リチウム含有金属複合酸化物材料、導電性高分子等が挙げられる。これらは、１種を単独で用いてもよく、また２種以上を任意に組み合わせて併用してもよい。 The negative electrode material is not particularly limited as long as it can electrochemically store and release lithium ions. Specific examples include carbon materials, alloy materials, lithium-containing metal composite oxide materials, conductive polymers, and the like. One of these may be used alone, or two or more of these may be used in combination as desired.
上記負極活物質としては、様々な熱分解条件での有機物の熱分解物や人造黒鉛、天然黒鉛等のリチウムを吸蔵・放出可能な炭素質材料；酸化錫、酸化ケイ素等のリチウムを吸蔵・放出可能な金属酸化物材料；リチウム金属；種々のリチウム合金；リチウム含有金属複合酸化物材料等を挙げることができる。これらの負極活物質は、２種以上を混合して用いてもよい。 As the negative electrode active material, a carbonaceous material capable of absorbing and desorbing lithium such as thermal decomposition products of organic matter and artificial graphite and natural graphite under various thermal decomposition conditions; and desorbing and releasing lithium such as tin oxide and silicon oxide Possible metal oxide materials; lithium metal; various lithium alloys; lithium-containing metal complex oxide materials and the like can be mentioned. These negative electrode active materials may be used as a mixture of two or more.
リチウムを吸蔵・放出可能な炭素質材料としては、種々の原料から得た易黒鉛性ピッチの高温処理によって製造された人造黒鉛若しくは精製天然黒鉛、又は、これらの黒鉛にピッチその他の有機物で表面処理を施した後炭化して得られるものが好ましく、天然黒鉛、人造黒鉛、人造炭素質物質並びに人造黒鉛質物質を４００～３２００℃の範囲で１回以上熱処理した炭素質材料、負極活物質層が少なくとも２種類以上の異なる結晶性を有する炭素質からなり、かつ／又はその異なる結晶性の炭素質が接する界面を有している炭素質材料、負極活物質層が少なくとも２種以上の異なる配向性の炭素質が接する界面を有している炭素質材料、から選ばれるものが、初期不可逆容量、高電流密度充放電特性のバランスがよくより好ましい。また、これらの炭素材料は、１種を単独で用いてもよく、２種以上を任意の組み合わせ及び比率で併用してもよい。 As carbonaceous materials capable of storing and releasing lithium, artificial graphite or purified natural graphite produced by high temperature treatment of graphitizable pitch obtained from various raw materials, or surface treatment of these graphites with pitch or other organic substances The material is preferably obtained by carbonization after application of carbon, a carbonaceous material obtained by heat-treating natural graphite, artificial graphite, artificial carbonaceous material and artificial graphitic material at a temperature of 400 A carbonaceous material comprising at least two or more kinds of different crystalline carbonaceous materials and / or having an interface in which the different crystalline carbonaceous materials are in contact, and at least two or more different orientations of the negative electrode active material layer The material selected from carbonaceous materials having an interface in contact with the carbonaceous material is more preferable because the balance between the initial irreversible capacity and the high current density charge / discharge characteristics is good. Moreover, these carbon materials may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.
上記の人造炭素質物質並びに人造黒鉛質物質を４００～３２００℃の範囲で１回以上熱処理した炭素質材料としては、石炭系コークス、石油系コークス、石炭系ピッチ、石油系ピッチ及びこれらピッチを酸化処理したもの、ニードルコークス、ピッチコークス及びこれらを一部黒鉛化した炭素剤、ファーネスブラック、アセチレンブラック、ピッチ系炭素繊維等の有機物の熱分解物、炭化可能な有機物及びこれらの炭化物、又は炭化可能な有機物をベンゼン、トルエン、キシレン、キノリン、ｎ－ヘキサン等の低分子有機溶剤に溶解させた溶液及びこれらの炭化物等が挙げられる。 As the above-mentioned artificial carbonaceous material and carbonaceous material obtained by heat treating artificial graphite material at 400 to 3200 ° C. one or more times, it is possible to oxidize coal coke, petroleum coke, coal pitch, petroleum pitch and these pitches. Treated, needle coke, pitch coke and carbon agents partially graphitized thereof, furnace black, acetylene black, pyrolyzate of organic matter such as pitch carbon fiber, carbonizable organic matter and carbides thereof, or carbonizable A solution obtained by dissolving the organic substance in a low molecular weight organic solvent such as benzene, toluene, xylene, quinoline, n-hexane and the like, carbides of these, and the like.
上記負極活物質として用いられる金属材料（但し、リチウムチタン複合酸化物を除く）としては、リチウムを吸蔵・放出可能であれば、リチウム単体、リチウム合金を形成する単体金属及び合金、又はそれらの酸化物、炭化物、窒化物、ケイ化物、硫化物若しくはリン化物等の化合物のいずれであってもよく、特に制限されない。リチウム合金を形成する単体金属及び合金としては、１３族及び１４族の金属・半金属元素を含む材料であることが好ましく、より好ましくはアルミニウム、ケイ素及びスズ（以下、「特定金属元素」と略記）の単体金属及びこれら原子を含む合金又は化合物である。これらは、１種を単独で用いてもよく、２種以上を任意の組み合わせ及び比率で併用してもよい。 As a metal material (but excluding lithium titanium complex oxide) used as the above-mentioned negative electrode active material, if lithium can be occluded and released, a single lithium, a single metal and an alloy forming a lithium alloy, or oxidation thereof It may be any of compounds such as carbides, nitrides, silicides, sulfides or phosphides, and is not particularly limited. The single metal and alloy forming the lithium alloy is preferably a material containing Group 13 and Group 14 metal / metalloid elements, more preferably aluminum, silicon and tin (hereinafter referred to as “specific metal elements”. And metals or alloys or compounds containing these atoms. One of these may be used alone, or two or more of these may be used in any combination and ratio.
特定金属元素から選ばれる少なくとも１種の原子を有する負極活物質としては、いずれか１種の特定金属元素の金属単体、２種以上の特定金属元素からなる合金、１種又は２種以上の特定金属元素とその他の１種又は２種以上の金属元素とからなる合金、並びに、１種又は２種以上の特定金属元素を含有する化合物、及びその化合物の酸化物、炭化物、窒化物、ケイ化物、硫化物若しくはリン化物等の複合化合物が挙げられる。負極活物質としてこれらの金属単体、合金又は金属化合物を用いることで、電池の高容量化が可能である。 As a negative electrode active material having at least one kind of atom selected from specific metal elements, a metal simple substance of any one kind of specific metal element, an alloy composed of two or more kinds of specific metal elements, one kind or two kinds or more of specification Alloy consisting of metal element and one or more other metal elements, compound containing one or more specified metal elements, and oxide, carbide, nitride, silicide of the compound And complex compounds such as sulfides and phosphides. By using these simple metals, alloys or metal compounds as the negative electrode active material, the capacity of the battery can be increased.
また、これらの複合化合物が、金属単体、合金又は非金属元素等の数種の元素と複雑に結合した化合物も挙げられる。具体的には、例えばケイ素やスズでは、これらの元素と負極として作動しない金属との合金を用いることができる。例えば、スズの場合、スズとケイ素以外で負極として作用する金属と、更に負極として動作しない金属と、非金属元素との組み合わせで５～６種の元素を含むような複雑な化合物も用いることができる。 Moreover, the compound which these composite compounds couple | bonded with several types of elements, such as a simple metal, an alloy, or a nonmetallic element, etc. is also mentioned. Specifically, for example, in silicon and tin, an alloy of these elements and a metal which does not operate as a negative electrode can be used. For example, in the case of tin, a complex compound containing 5 to 6 elements in combination of a metal other than tin and silicon which acts as a negative electrode, a metal which does not further act as a negative electrode, and a nonmetallic element may be used it can.
具体的には、Ｓｉ単体、ＳｉＢ４、ＳｉＢ６、Ｍｇ２Ｓｉ、Ｎｉ２Ｓｉ、ＴｉＳｉ２、ＭｏＳｉ２、ＣｏＳｉ２、ＮｉＳｉ２、ＣａＳｉ２、ＣｒＳｉ２、Ｃｕ６Ｓｉ、ＦｅＳｉ２、ＭｎＳｉ２、ＮｂＳｉ２、ＴａＳｉ２、ＶＳｉ２、ＷＳｉ２、ＺｎＳｉ２、ＳｉＣ、Ｓｉ３Ｎ４、Ｓｉ２Ｎ２Ｏ、ＳｉＯｖ（０＜ｖ≦２）、ＬｉＳｉＯあるいはスズ単体、ＳｎＳｉＯ３、ＬｉＳｎＯ、Ｍｇ２Ｓｎ、ＳｎＯｗ（０＜ｗ≦２）が挙げられる。
また、Ｓｉ又はＳｎを第一の構成元素とし、それに加えて第２、第３の構成元素を含む複合材料が挙げられる。第２の構成元素は、例えば、コバルト、鉄、マグネシウム、チタン、バナジウム、クロム、マンガン、ニッケル、銅、亜鉛、ガリウム及びジルコニウムのうち少なくとも１種である。第３の構成元素は、例えば、ホウ素、炭素、アルミニウム及びリンのうち少なくとも１種である。
特に、高い電池容量及び優れた電池特性が得られることから、上記金属材料として、ケイ素又はスズの単体（微量の不純物を含んでよい）、ＳｉＯｖ（０＜ｖ≦２）、ＳｎＯｗ（０≦ｗ≦２）、Ｓｉ－Ｃｏ－Ｃ複合材料、Ｓｉ－Ｎｉ－Ｃ複合材料、Ｓｎ－Ｃｏ－Ｃ複合材料、Ｓｎ－Ｎｉ－Ｃ複合材料が好ましい。 Specifically, Si simple substance, SiB 4 , SiB 6 , Mg 2 Si, Ni 2 Si, TiSi 2 , MoSi 2 , MoSi 2 , CoSi 2 , NiSi 2 , CaSi 2 , CrSi 2 , Cu 6 Si, FeSi 2 , MnSi 2 , NbSi 2 , TaSi 2 , VSi 2 , WSi 2 , ZnSi 2 , SiC, Si 3 N 4 , Si 2 N 2 O, SiO v (0 <v ≦ 2), LiSiO or tin alone, SnSiO 3 , LiSnO, Mg 2 Sn, SnO w (0 <w ≦ 2) can be mentioned.
Moreover, the composite material which makes Si or Sn a 1st constitutent element, and contains the 2nd, 3rd constitutent element in addition to it is mentioned. The second constituent element is, for example, at least one of cobalt, iron, magnesium, titanium, vanadium, chromium, manganese, nickel, copper, zinc, gallium and zirconium. The third constituent element is, for example, at least one of boron, carbon, aluminum and phosphorus.
In particular, silicon or tin alone (may contain a trace amount of impurities), SiO v (0 <v ≦ 2), SnO w (0) may be used as the metal material because high battery capacity and excellent battery characteristics can be obtained. ≦ w ≦ 2), Si—Co—C composite, Si—Ni—C composite, Sn—Co—C composite, and Sn—Ni—C composite are preferable.
負極活物質として用いられるリチウム含有金属複合酸化物材料としては、リチウムを吸蔵・放出可能であれば、特に制限されないが、高電流密度充放電特性の点からチタン及びリチウムを含有する材料が好ましく、より好ましくはチタンを含むリチウム含有複合金属酸化物材料が好ましく、更にリチウムとチタンの複合酸化物（以下、「リチウムチタン複合酸化物」と略記）が好ましい。すなわち、スピネル構造を有するリチウムチタン複合酸化物を、電解液電池用負極活物質に含有させて用いると、出力抵抗が大きく低減するので特に好ましい。 The lithium-containing metal complex oxide material used as the negative electrode active material is not particularly limited as long as it can occlude and release lithium, but a material containing titanium and lithium is preferable in terms of high current density charge and discharge characteristics, More preferably, a lithium-containing composite metal oxide material containing titanium is preferable, and a composite oxide of lithium and titanium (hereinafter abbreviated as "lithium-titanium composite oxide") is more preferable. That is, when a lithium titanium composite oxide having a spinel structure is used by being contained in a negative electrode active material for an electrolyte battery, the output resistance is greatly reduced, which is particularly preferable.
上記リチウムチタン複合酸化物としては、一般式：
ＬｉｘＴｉｙＭｚＯ４
［式中、Ｍは、Ｎａ、Ｋ、Ｃｏ、Ａｌ、Ｆｅ、Ｔｉ、Ｍｇ、Ｃｒ、Ｇａ、Ｃｕ、Ｚｎ及びＮｂからなる群より選ばれる少なくとも１種の元素を表わす。］
で表される化合物であることが好ましい。
上記組成の中でも、
（ｉ）１．２≦ｘ≦１．４、１．５≦ｙ≦１．７、ｚ＝０
（ｉｉ）０．９≦ｘ≦１．１、１．９≦ｙ≦２．１、ｚ＝０
（ｉｉｉ）０．７≦ｘ≦０．９、２．１≦ｙ≦２．３、ｚ＝０
の構造が、電池性能のバランスが良好なため特に好ましい。 As said lithium titanium complex oxide, general formula:
Li x Ti y M z O 4
[Wherein, M represents at least one element selected from the group consisting of Na, K, Co, Al, Fe, Ti, Mg, Cr, Ga, Cu, Zn and Nb. ]
It is preferable that it is a compound represented by these.
Among the above compositions,
(I) 1.2 ≦ x ≦ 1.4, 1.5 ≦ y ≦ 1.7, z = 0
(Ii) 0.9 ≦ x ≦ 1.1, 1.9 ≦ y ≦ 2.1, z = 0
(Iii) 0.7 ≦ x ≦ 0.9, 2.1 ≦ y ≦ 2.3, z = 0
Is particularly preferable because the battery performance is well balanced.
上記化合物の特に好ましい代表的な組成は、（ｉ）ではＬｉ４／３Ｔｉ５／３Ｏ４、（ｉｉ）ではＬｉ１Ｔｉ２Ｏ４、（ｉｉｉ）ではＬｉ４／５Ｔｉ１１／５Ｏ４である。また、Ｚ≠０の構造については、例えば、Ｌｉ４／３Ｔｉ４／３Ａｌ１／３Ｏ４が好ましいものとして挙げられる。 Particularly preferable representative compositions of the above compounds are Li 4/3 Ti 5/3 O 4 in (i), Li 1 Ti 2 O 4 in (ii), and Li 4/5 Ti 11/5 O in (iii). 4 In addition, for the structure of Z ≠ 0, for example, Li 4/3 Ti 4/3 Al 1/3 O 4 is mentioned as a preferable one.
上記負極合剤は、更に、結着剤、増粘剤、導電材を含むことが好ましい。 The negative electrode mixture preferably further contains a binder, a thickener, and a conductive material.
上記結着剤としては、上述した、正極に用いることができる結着剤と同様のものが挙げられる。負極活物質に対する結着剤の割合は、０．１質量％以上が好ましく、０．５質量％以上が更に好ましく、０．６質量％以上が特に好ましく、また、２０質量％以下が好ましく、１５質量％以下がより好ましく、１０質量％以下が更に好ましく、８質量％以下が特に好ましい。負極活物質に対する結着剤の割合が、上記範囲を上回ると、結着剤量が電池容量に寄与しない結着剤割合が増加して、電池容量の低下を招く場合がある。また、上記範囲を下回ると、負極電極の強度低下を招く場合がある。 Examples of the binding agent include the same as the binding agent that can be used for the positive electrode described above. The ratio of the binder to the negative electrode active material is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, particularly preferably 0.6% by mass or more, and preferably 20% by mass or less, 15 Mass% or less is more preferable, 10 mass% or less is further preferable, and 8 mass% or less is particularly preferable. When the ratio of the binder to the negative electrode active material exceeds the above range, the binder ratio in which the amount of the binder does not contribute to the battery capacity may increase, which may result in a decrease in the battery capacity. Moreover, if it is less than the said range, strength reduction of a negative electrode may be caused.
特に、ＳＢＲに代表されるゴム状高分子を主要成分に含有する場合には、負極活物質に対する結着剤の割合は、通常０．１質量％以上であり、０．５質量％以上が好ましく、０．６質量％以上が更に好ましく、また、通常５質量％以下であり、３質量％以下が好ましく、２質量％以下が更に好ましい。また、ポリフッ化ビニリデンに代表されるフッ素系高分子を主要成分に含有する場合には負極活物質に対する割合は、通常１質量％以上であり、２質量％以上が好ましく、３質量％以上が更に好ましく、また、通常１５質量％以下であり、１０質量％以下が好ましく、８質量％以下が更に好ましい。 In particular, when the main component contains a rubbery polymer represented by SBR, the ratio of the binder to the negative electrode active material is usually 0.1% by mass or more, and preferably 0.5% by mass or more. The content is more preferably 0.6% by mass or more, and usually 5% by mass or less, preferably 3% by mass or less, and more preferably 2% by mass or less. When the fluorine-containing polymer represented by polyvinylidene fluoride is contained in the main component, the ratio to the negative electrode active material is usually 1% by mass or more, preferably 2% by mass or more, and 3% by mass or more Moreover, it is 15 mass% or less normally, 10 mass% or less is preferable, and 8 mass% or less is still more preferable.
上記増粘剤としては、上述した、正極に用いることができる増粘剤と同様のものが挙げられる。負極活物質に対する増粘剤の割合は、通常０．１質量％以上であり、０．５質量％以上が好ましく、０．６質量％以上が更に好ましく、また、通常５質量％以下であり、３質量％以下が好ましく、２質量％以下が更に好ましい。負極活物質に対する増粘剤の割合が、上記範囲を下回ると、著しく塗布性が低下する場合がある。また、上記範囲を上回ると、負極活物質層に占める負極活物質の割合が低下し、電池の容量が低下する問題や負極活物質間の抵抗が増大する場合がある。 As said thickener, the thing similar to the thickener mentioned above and which can be used for a positive electrode is mentioned. The ratio of the thickener to the negative electrode active material is usually 0.1% by mass or more, preferably 0.5% by mass or more, more preferably 0.6% by mass or more, and usually 5% by mass or less. 3 mass% or less is preferable, and 2 mass% or less is still more preferable. When the ratio of the thickener to the negative electrode active material is below the above range, the coatability may be significantly reduced. If the above range is exceeded, the proportion of the negative electrode active material in the negative electrode active material layer may be reduced, and the battery capacity may be reduced or the resistance between the negative electrode active material may be increased.
負極の導電材としては、銅やニッケル等の金属材料；グラファイト、カーボンブラック等の炭素材料等が挙げられる。 Examples of the conductive material of the negative electrode include metal materials such as copper and nickel; and carbon materials such as graphite and carbon black.
スラリーを形成するための溶媒としては、負極活物質、結着剤、並びに必要に応じて使用される増粘剤及び導電材を溶解又は分散することが可能な溶媒であれば、その種類に特に制限はなく、水系溶媒と有機系溶媒のどちらを用いてもよい。
水系溶媒としては、水、アルコール等が挙げられ、有機系溶媒としてはＮ－メチルピロリドン（ＮＭＰ）、ジメチルホルムアミド、ジメチルアセトアミド、メチルエチルケトン、シクロヘキサノン、酢酸メチル、アクリル酸メチル、ジエチルトリアミン、Ｎ，Ｎ－ジメチルアミノプロピルアミン、テトラヒドロフラン（ＴＨＦ）、トルエン、アセトン、ジエチルエーテル、ジメチルアセトアミド、ヘキサメチルホスファルアミド、ジメチルスルホキシド、ベンゼン、キシレン、キノリン、ピリジン、メチルナフタレン、ヘキサン等が挙げられる。 As a solvent for forming a slurry, a solvent capable of dissolving or dispersing a negative electrode active material, a binder, a thickener used as needed, and a conductive material can be particularly selected. There is no limitation, and either an aqueous solvent or an organic solvent may be used.
Examples of the aqueous solvent include water, alcohol and the like, and examples of the organic solvent include N-methylpyrrolidone (NMP), dimethylformamide, dimethylacetamide, methylacetamide, cyclohexanone, methyl acetate, methyl acrylate, diethyltriamine, N, N- Dimethylaminopropylamine, tetrahydrofuran (THF), toluene, acetone, diethyl ether, dimethylacetamide, hexamethylphosphide, dimethylsulfoxide, benzene, xylene, quinoline, pyridine, methylnaphthalene, hexane and the like can be mentioned.
負極用集電体の材質としては、銅、ニッケル又はステンレス等が挙げられる。なかでも、薄膜に加工しやすいという点、及び、コストの点から銅箔が好ましい。 Examples of the material of the current collector for the negative electrode include copper, nickel, and stainless steel. Among them, copper foil is preferable in terms of easy processing into a thin film and cost.
集電体の厚さは、通常１μｍ以上、好ましくは５μｍ以上であり、通常１００μｍ以下、好ましくは５０μｍ以下である。負極集電体の厚さが厚すぎると、電池全体の容量が低下し過ぎることがあり、逆に薄すぎると取扱いが困難になることがある。 The thickness of the current collector is usually 1 μm or more, preferably 5 μm or more, and usually 100 μm or less, preferably 50 μm or less. If the thickness of the negative electrode current collector is too thick, the capacity of the entire battery may be too low. Conversely, if the thickness is too thin, the handling may be difficult.
負極の製造は、常法によればよい。例えば、上記負極材料に、上述した結着剤、増粘剤、導電材、溶媒等を加えてスラリー状とし、集電体に塗布し、乾燥した後にプレスして高密度化する方法が挙げられる。また、合金材料を用いる場合には、蒸着法、スパッタ法、メッキ法等の手法により、上述の負極活物質を含有する薄膜層（負極活物質層）を形成する方法も用いられる。 The production of the negative electrode may be performed according to a conventional method. For example, the above-mentioned negative electrode material may be added with the above-mentioned binder, thickener, conductive material, solvent and the like to form a slurry, which is coated on a current collector, dried and then pressed to obtain high density. . Moreover, when using an alloy material, the method of forming the thin film layer (negative electrode active material layer) containing the above-mentioned negative electrode active material by methods, such as a vapor deposition method, a sputtering method, and a plating method, is also used.
負極活物質を電極化した際の電極構造は特に制限されないが、集電体上に存在している負極活物質の密度は、１ｇ・ｃｍ－３以上が好ましく、１．２ｇ・ｃｍ－３以上が更に好ましく、１．３ｇ・ｃｍ－３以上が特に好ましく、また、２．２ｇ・ｃｍ－３以下が好ましく、２．１ｇ・ｃｍ－３以下がより好ましく、２．０ｇ・ｃｍ－３以下が更に好ましく、１．９ｇ・ｃｍ－３以下が特に好ましい。集電体上に存在している負極活物質の密度が、上記範囲を上回ると、負極活物質粒子が破壊され、初期不可逆容量の増加や、集電体／負極活物質界面付近への電解液の浸透性低下による高電流密度充放電特性悪化を招く場合がある。また、上記範囲を下回ると、負極活物質間の導電性が低下し、電池抵抗が増大し、単位容積当たりの容量が低下する場合がある。 The electrode structure when making the negative electrode active material into an electrode is not particularly limited, but the density of the negative electrode active material present on the current collector is preferably 1 g · cm −3 or more, and 1.2 g · cm −3 or more Is more preferable, 1.3 g · cm −3 or more is particularly preferable, and 2.2 g · cm −3 or less is preferable, 2.1 g · cm −3 or less is more preferable, and 2.0 g · cm −3 or less More preferably, it is particularly preferably 1.9 g · cm −3 or less. When the density of the negative electrode active material present on the current collector exceeds the above range, the negative electrode active material particles are destroyed, and the initial irreversible capacity is increased, and the electrolyte solution near the current collector / negative electrode active material interface In some cases, the high current density charge / discharge characteristics may be deteriorated due to the decrease in the permeability of the If the above range is exceeded, the conductivity between the negative electrode active materials may be reduced, the battery resistance may be increased, and the capacity per unit volume may be reduced.
負極板の厚さは用いられる正極板に合わせて設計されるものであり、特に制限されないが、芯材の金属箔厚さを差し引いた合剤層の厚さは通常１５μｍ以上、好ましくは２０μｍ以上、より好ましくは３０μｍ以上、また、通常３００μｍ以下、好ましくは２８０μｍ以下、より好ましくは２５０μｍ以下が望ましい。 The thickness of the negative electrode plate is designed according to the positive electrode plate to be used and is not particularly limited, but the thickness of the mixture layer obtained by subtracting the metal foil thickness of the core material is usually 15 μm or more, preferably 20 μm or more More preferably, it is 30 μm or more, and usually 300 μm or less, preferably 280 μm or less, more preferably 250 μm or less.
また、上記負極板の表面に、これとは異なる組成の物質が付着したものを用いてもよい。表面付着物質としては酸化アルミニウム、酸化ケイ素、酸化チタン、酸化ジルコニウム、酸化マグネシウム、酸化カルシウム、酸化ホウ素、酸化アンチモン、酸化ビスマス等の酸化物、硫酸リチウム、硫酸ナトリウム、硫酸カリウム、硫酸マグネシウム、硫酸カルシウム、硫酸アルミニウム等の硫酸塩、炭酸リチウム、炭酸カルシウム、炭酸マグネシウム等の炭酸塩等が挙げられる。 Moreover, you may use that to which the substance of the composition different from this adhered on the surface of the said negative electrode plate. As surface adhesion substances, aluminum oxide, silicon oxide, titanium oxide, zirconium oxide, magnesium oxide, calcium oxide, boron oxide, antimony oxide, oxides such as bismuth oxide, lithium sulfate, sodium sulfate, potassium sulfate, magnesium sulfate, calcium sulfate And sulfates such as aluminum sulfate; and carbonates such as lithium carbonate, calcium carbonate, and magnesium carbonate.
＜セパレータ＞
本発明のリチウムイオン二次電池は、更に、セパレータを備えることが好ましい。
上記セパレータの材質や形状は、電解液に安定であり、かつ、保液性に優れていれば特に限定されず、公知のものを使用することができる。なかでも、本発明の電解液に対し安定な材料で形成された、樹脂、ガラス繊維、無機物等が用いられ、保液性に優れた多孔性シート又は不織布状の形態の物等を用いるのが好ましい。 <Separator>
The lithium ion secondary battery of the present invention preferably further comprises a separator.
The material and shape of the separator are not particularly limited as long as they are stable to the electrolytic solution and excellent in liquid retention, and known materials can be used. Among these, resins, glass fibers, inorganic substances, etc., which are formed of a material stable to the electrolytic solution of the present invention, are used, and porous sheet or non-woven fabric-like articles etc. excellent in liquid retention are used. preferable.
樹脂、ガラス繊維セパレータの材料としては、例えば、ポリエチレン、ポリプロピレン等のポリオレフィン、芳香族ポリアミド、ポリテトラフルオロエチレン、ポリエーテルスルホン、ガラスフィルター等を用いることができる。ポリプロピレン／ポリエチレン２層フィルム、ポリプロピレン／ポリエチレン／ポリプロピレン３層フィルム等、これらの材料は１種を単独で用いてもよく、２種以上を任意の組み合わせ及び比率で併用してもよい。なかでも、上記セパレータは、電解液の浸透性やシャットダウン効果が良好である点で、ポリエチレン、ポリプロピレン等のポリオレフィンを原料とする多孔性シート又は不織布等であることが好ましい。 As a material of resin and a glass fiber separator, polyolefins, such as polyethylene and a polypropylene, aromatic polyamide, polytetrafluoroethylene, polyether sulfone, a glass filter etc. can be used, for example. One of these materials such as polypropylene / polyethylene two-layer film, polypropylene / polyethylene / polypropylene three-layer film may be used alone, or two or more thereof may be used in any combination and ratio. Among them, the separator is preferably a porous sheet or a non-woven fabric or the like that uses a polyolefin such as polyethylene or polypropylene as a raw material in that the permeability of the electrolytic solution and the shutdown effect are good.
セパレータの厚さは任意であるが、通常１μｍ以上であり、５μｍ以上が好ましく、８μｍ以上が更に好ましく、また、通常５０μｍ以下であり、４０μｍ以下が好ましく、３０μｍ以下が更に好ましい。セパレータが、上記範囲より薄過ぎると、絶縁性や機械的強度が低下する場合がある。また、上記範囲より厚過ぎると、レート特性等の電池性能が低下する場合があるばかりでなく、電解液電池全体としてのエネルギー密度が低下する場合がある。 The thickness of the separator is arbitrary, but is usually 1 μm or more, preferably 5 μm or more, more preferably 8 μm or more, and usually 50 μm or less, preferably 40 μm or less, still more preferably 30 μm or less. If the separator is thinner than the above range, the insulation and mechanical strength may be reduced. If the thickness is more than the above range, not only the battery performance such as rate characteristics may be degraded, but also the energy density of the entire electrolyte battery may be degraded.
更に、セパレータとして多孔性シートや不織布等の多孔質のものを用いる場合、セパレータの空孔率は任意であるが、通常２０％以上であり、３５％以上が好ましく、４５％以上が更に好ましく、また、通常９０％以下であり、８５％以下が好ましく、７５％以下が更に好ましい。空孔率が、上記範囲より小さ過ぎると、膜抵抗が大きくなってレート特性が悪化する傾向がある。また、上記範囲より大き過ぎると、セパレータの機械的強度が低下し、絶縁性が低下する傾向にある。 Furthermore, when a porous sheet such as a porous sheet or a non-woven fabric is used as the separator, the porosity of the separator is optional, but is usually 20% or more, preferably 35% or more, and more preferably 45% or more, Also, it is usually 90% or less, preferably 85% or less, and more preferably 75% or less. When the porosity is smaller than the above range, the film resistance tends to be increased and the rate characteristic tends to be deteriorated. Moreover, when it is larger than the said range, it exists in the tendency for the mechanical strength of a separator to fall and for insulation to fall.
また、セパレータの平均孔径も任意であるが、通常０．５μｍ以下であり、０．２μｍ以下が好ましく、また、通常０．０５μｍ以上である。平均孔径が、上記範囲を上回ると、短絡が生じ易くなる。また、上記範囲を下回ると、膜抵抗が大きくなりレート特性が低下する場合がある。 The average pore diameter of the separator is also optional, but is usually 0.5 μm or less, preferably 0.2 μm or less, and usually 0.05 μm or more. When the average pore size exceeds the above range, a short circuit is likely to occur. If the above range is exceeded, the film resistance may increase and the rate characteristics may deteriorate.
一方、無機物の材料としては、例えば、アルミナや二酸化ケイ素等の酸化物、窒化アルミや窒化ケイ素等の窒化物、硫酸バリウムや硫酸カルシウム等の硫酸塩が用いられ、粒子形状若しくは繊維形状のものが用いられる。 On the other hand, as the inorganic material, for example, oxides such as alumina and silicon dioxide, nitrides such as aluminum nitride and silicon nitride, and sulfates such as barium sulfate and calcium sulfate are used, and those having a particle shape or fiber shape are used. Used.
形態としては、不織布、織布、微多孔性フィルム等の薄膜形状のものが用いられる。薄膜形状では、孔径が０．０１～１μｍ、厚さが５～５０μｍのものが好適に用いられる。上記の独立した薄膜形状以外に、樹脂製の結着剤を用いて上記無機物の粒子を含有する複合多孔層を正極及び／又は負極の表層に形成させてなるセパレータを用いることができる。例えば、正極の両面に９０％粒径が１μｍ未満のアルミナ粒子を、フッ素樹脂を結着剤として多孔層を形成させることが挙げられる。 As the form, a thin film such as a non-woven fabric, a woven fabric and a microporous film is used. As the thin film shape, one having a pore diameter of 0.01 to 1 μm and a thickness of 5 to 50 μm is suitably used. In addition to the above-described independent thin film shape, a separator can be used in which a composite porous layer containing particles of the above-mentioned inorganic substance is formed on the surface layer of the positive electrode and / or the negative electrode using a resin binder. For example, alumina particles having a 90% particle size of less than 1 μm may be formed on both sides of the positive electrode to form a porous layer using a fluorine resin as a binder.
＜電池設計＞
電極群は、上記の正極板と負極板とを上記のセパレータを介してなる積層構造のもの、及び上記の正極板と負極板とを上記のセパレータを介して渦巻き状に捲回した構造のもののいずれでもよい。電極群の体積が電池内容積に占める割合（以下、電極群占有率と称する）は、通常４０％以上であり、５０％以上が好ましく、また、通常９０％以下であり、８０％以下が好ましい。 <Battery design>
The electrode group has a laminated structure in which the positive electrode plate and the negative electrode plate described above are intervened by the separator, and a structure in which the positive electrode plate and the negative electrode plate are spirally wound through the separator. Any one may be used. The ratio of the volume of the electrode group to the internal volume of the battery (hereinafter referred to as the electrode group occupancy rate) is usually 40% or more, preferably 50% or more, and usually 90% or less, preferably 80% or less .
電極群占有率が、上記範囲を下回ると、電池容量が小さくなる。また、上記範囲を上回ると空隙スペースが少なく、電池が高温になることによって部材が膨張したり電解質の液成分の蒸気圧が高くなったりして内部圧力が上昇し、電池としての充放電繰り返し性能や高温保存等の諸特性を低下させたり、更には、内部圧力を外に逃がすガス放出弁が作動する場合がある。 When the electrode group occupancy rate falls below the above range, the battery capacity decreases. Further, when the above range is exceeded, the void space is small, the battery becomes high temperature, the members expand, the vapor pressure of the liquid component of the electrolyte becomes high, and the internal pressure rises, and the charge and discharge repetition performance as the battery And may deteriorate various characteristics such as high temperature storage, and may further operate a gas release valve that releases the internal pressure to the outside.
集電構造は、特に制限されないが、本発明の電解液による高電流密度の充放電特性の向上をより効果的に実現するには、配線部分や接合部分の抵抗を低減する構造にすることが好ましい。この様に内部抵抗を低減させた場合、本発明の電解液を使用した効果は特に良好に発揮される。 Although the current collecting structure is not particularly limited, in order to more effectively realize the improvement of the charge and discharge characteristics of the high current density by the electrolytic solution of the present invention, the structure of reducing the resistance of the wiring portion and the bonding portion may be used. preferable. When the internal resistance is thus reduced, the effect of using the electrolytic solution of the present invention is exhibited particularly well.
電極群が上記の積層構造のものでは、各電極層の金属芯部分を束ねて端子に溶接して形成される構造が好適に用いられる。一枚の電極面積が大きくなる場合には、内部抵抗が大きくなるので、電極内に複数の端子を設けて抵抗を低減することも好適に用いられる。電極群が上記の捲回構造のものでは、正極及び負極にそれぞれ複数のリード構造を設け、端子に束ねることにより、内部抵抗を低くすることができる。 When the electrode group has the above-described laminated structure, a structure formed by bundling metal core portions of the respective electrode layers and welding them to terminals is suitably used. When the area of one electrode increases, the internal resistance increases, so it is also preferable to provide a plurality of terminals in the electrode to reduce the resistance. When the electrode group has the above-described wound structure, the internal resistance can be lowered by providing a plurality of lead structures on the positive electrode and the negative electrode and bundling them in the terminals.
外装ケースの材質は用いられる電解液に対して安定な物質であれば特に制限されない。具体的には、ニッケルめっき鋼板、ステンレス、アルミニウム又はアルミニウム合金、マグネシウム合金等の金属類、又は、樹脂とアルミ箔との積層フィルム（ラミネートフィルム）が用いられる。軽量化の観点から、アルミニウム又はアルミニウム合金の金属、ラミネートフィルムが好適に用いられる。 The material of the outer case is not particularly limited as long as the material is stable to the electrolyte used. Specifically, a nickel-plated steel sheet, metals such as stainless steel, aluminum or aluminum alloy, magnesium alloy or the like, or a laminated film (laminated film) of a resin and an aluminum foil is used. From the viewpoint of weight reduction, metals of aluminum or aluminum alloy and laminate films are preferably used.
金属類を用いる外装ケースでは、レーザー溶接、抵抗溶接、超音波溶接により金属同士を溶着して封止密閉構造とするもの、若しくは、樹脂製ガスケットを介して上記金属類を用いてかしめ構造とするものが挙げられる。上記ラミネートフィルムを用いる外装ケースでは、樹脂層同士を熱融着することにより封止密閉構造とするもの等が挙げられる。シール性を上げるために、上記樹脂層の間にラミネートフィルムに用いられる樹脂と異なる樹脂を介在させてもよい。特に、集電端子を介して樹脂層を熱融着して密閉構造とする場合には、金属と樹脂との接合になるので、介在する樹脂として極性基を有する樹脂や極性基を導入した変成樹脂が好適に用いられる。 In the outer case using metals, the metals are welded to form a hermetically sealed structure by laser welding, resistance welding, ultrasonic welding, or a caulking structure is formed using the above metals via a resin gasket. The thing is mentioned. In the outer case using the above-mentioned laminated film, those having a sealing and sealing structure by thermally fusing the resin layers to each other may be mentioned. In order to improve the sealing property, a resin different from the resin used for the laminate film may be interposed between the resin layers. In particular, in the case where the resin layer is heat-sealed through the current collection terminal to form a sealed structure, the metal and the resin are joined, and therefore, a resin having a polar group or a modification having a polar group introduced as an intervening resin Resin is preferably used.
本発明のリチウムイオン二次電池の形状は任意であり、例えば、円筒型、角型、ラミネート型、コイン型、大型等の形状が挙げられる。なお、正極、負極、セパレータの形状及び構成は、それぞれの電池の形状に応じて変更して使用することができる。 The shape of the lithium ion secondary battery of the present invention is arbitrary, and examples thereof include cylindrical, square, laminate, coin and large shapes. The shapes and configurations of the positive electrode, the negative electrode, and the separator can be changed and used according to the shapes of the respective batteries.
また、本発明のリチウムイオン二次電池を備えるモジュールも本発明の一つである。 In addition, a module including the lithium ion secondary battery of the present invention is also one of the present invention.
また、正極、負極、及び、上述の電解液を備え、上記正極は、正極集電体及び正極活物質を含む正極活物質層を備えており、上記正極活物質は、Ｍｎを含むことを特徴とするリチウムイオン二次電池も、好適な態様の一つである。Ｍｎを含む正極活物質を含む正極活物質層を備えることから、上記リチウムイオン二次電池は、高温保存特性により一層優れる。 A positive electrode, a negative electrode, and the above-described electrolyte solution, wherein the positive electrode includes a positive electrode current collector and a positive electrode active material layer including a positive electrode active material, and the positive electrode active material includes Mn. The lithium ion secondary battery is also one of the preferred embodiments. Since the positive electrode active material layer containing a positive electrode active material containing Mn is provided, the lithium ion secondary battery is further excellent in high-temperature storage characteristics.
上記Ｍｎを含む正極活物質としては、エネルギー密度が高く、高出力なリチウムイオン二次電池を提供できる点から、ＬｉＭｎ１．５Ｎｉ０．５Ｏ４、ＬｉＮｉ０．５Ｃｏ０．２Ｍｎ０．３Ｏ２、ＬｉＮｉ０．６Ｃｏ０．２Ｍｎ０．２Ｏ２が好ましい。 As the positive electrode active material containing Mn, it is possible to provide a lithium ion secondary battery having a high energy density and a high output, LiMn 1.5 Ni 0.5 O 4 , LiNi 0.5 Co 0.2 Mn 0 .3 O 2 , LiNi 0.6 Co 0.2 Mn 0.2 O 2 is preferred.
上記正極活物質の、正極活物質層中の含有量は、好ましくは８０質量％以上、より好ましくは８２質量％以上、特に好ましくは８４質量％以上である。また上限は、好ましくは９９質量％以下、より好ましくは９８質量％以下である。正極活物質層中の正極活物質の含有量が低いと電気容量が不十分となる場合がある。逆に含有量が高すぎると正極の強度が不足する場合がある。 The content of the positive electrode active material in the positive electrode active material layer is preferably 80% by mass or more, more preferably 82% by mass or more, and particularly preferably 84% by mass or more. The upper limit is preferably 99% by mass or less, more preferably 98% by mass or less. If the content of the positive electrode active material in the positive electrode active material layer is low, the electrical capacity may be insufficient. Conversely, if the content is too high, the strength of the positive electrode may be insufficient.
上記正極活物質層は、更に、導電材、増粘剤及び結着剤を含んでもよい。 The positive electrode active material layer may further contain a conductive material, a thickener and a binder.
上記結着剤としては、電極製造時に使用する溶媒や電解液に対して安全な材料であれば、任意のものを使用することができ、例えば、ポリフッ化ビニリデン、ポリテトラフルオロエチレン、ポリエチレン、ポリプロピレン、ＳＢＲ（スチレン・ブタジエンゴム）、イソプレンゴム、ブタジエンゴム、エチレン－アクリル酸共重合体、エチレン－メタクリル酸共重合体、ポリエチレンテレフタレート、ポリメチルメタクリレート、ポリイミド、芳香族ポリアミド、セルロース、ニトロセルロース、ＮＢＲ（アクリロニトリル－ブタジエンゴム）、フッ素ゴム、エチレン－プロピレンゴム、スチレン・ブタジエン・スチレンブロック共重合体又はその水素添加物、ＥＰＤＭ（エチレン・プロピレン・ジエン三元共重合体）、スチレン・エチレン・ブタジエン・エチレン共重合体、スチレン・イソプレン・スチレンブロック共重合体又はその水素添加物、シンジオタクチック－１，２－ポリブタジエン、ポリ酢酸ビニル、エチレン・酢酸ビニル共重合体、プロピレン・α－オレフィン共重合体、フッ素化ポリフッ化ビニリデン、テトラフルオロエチレン・エチレン共重合体、アルカリ金属イオン（特にリチウムイオン）のイオン伝導性を有する高分子組成物等が挙げられる。なお、これらの物質は、１種を単独で用いてもよく、２種以上を任意の組み合わせ及び比率で併用してもよい。 As the above-mentioned binder, any material can be used as long as it is a material safe to the solvent and the electrolyte used in the production of the electrode. For example, polyvinylidene fluoride, polytetrafluoroethylene, polyethylene, polypropylene , SBR (styrene-butadiene rubber), isoprene rubber, butadiene rubber, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, polyethylene terephthalate, polymethyl methacrylate, polyimide, aromatic polyamide, cellulose, nitrocellulose, NBR (Acrylonitrile-butadiene rubber), fluororubber, ethylene-propylene rubber, styrene / butadiene / styrene block copolymer or a hydrogenated product thereof, EPDM (ethylene / propylene / diene terpolymer), styrene / ethylene / Tadiene / ethylene copolymer, styrene / isoprene / styrene block copolymer or a hydrogenated product thereof, syndiotactic-1,2-polybutadiene, polyvinyl acetate, ethylene / vinyl acetate copolymer, propylene / α-olefin copolymer Examples thereof include polymers, fluorinated polyvinylidene fluoride, tetrafluoroethylene / ethylene copolymers, and polymer compositions having ion conductivity of alkali metal ions (particularly lithium ions). One of these substances may be used alone, or two or more of these substances may be used in any combination and ratio.
結着剤の含有量は、正極活物質層中の結着剤の割合として、通常０．１質量％以上、好ましくは１質量％以上、更に好ましくは１．５質量％以上であり、また、通常８０質量％以下、好ましくは６０質量％以下、更に好ましくは４０質量％以下、最も好ましくは１０質量％以下である。結着剤の割合が低すぎると、正極活物質を十分保持できずに正極の機械的強度が不足し、サイクル特性等の電池性能を悪化させてしまう場合がある。一方で、高すぎると、電池容量や導電性の低下につながる場合がある。 The content of the binder is usually 0.1% by mass or more, preferably 1% by mass or more, more preferably 1.5% by mass or more, as a ratio of the binder in the positive electrode active material layer. Usually, it is 80% by mass or less, preferably 60% by mass or less, more preferably 40% by mass or less, and most preferably 10% by mass or less. If the proportion of the binder is too low, the positive electrode active material can not be sufficiently retained, and the mechanical strength of the positive electrode is insufficient, which may deteriorate battery performance such as cycle characteristics. On the other hand, if it is too high, it may lead to a decrease in battery capacity and conductivity.
上記増粘剤としては、カルボキシメチルセルロース、メチルセルロース、ヒドロキシメチルセルロース、エチルセルロース、ポリビニルアルコール、酸化スターチ、リン酸化スターチ、カゼイン及びこれらの塩等が挙げられる。１種を単独で用いても、２種以上を任意の組み合わせ及び比率で併用してもよい。 Examples of the thickener include carboxymethylcellulose, methylcellulose, hydroxymethylcellulose, ethylcellulose, polyvinyl alcohol, oxidized starch, phosphorylated starch, casein and salts thereof. One type may be used alone, or two or more types may be used in any combination and ratio.
活物質に対する増粘剤の割合は、通常０．１質量％以上、好ましくは０．２質量％以上、より好ましくは０．３質量％以上であり、また、通常５質量％以下、好ましくは３質量％以下、より好ましくは２質量％以下の範囲である。この範囲を下回ると、著しく塗布性が低下する場合がある。上回ると、正極活物質層に占める活物質の割合が低下し、電池の容量が低下する問題や正極活物質間の抵抗が増大する問題が生じる場合がある。 The ratio of the thickener to the active material is usually 0.1% by mass or more, preferably 0.2% by mass or more, more preferably 0.3% by mass or more, and usually 5% by mass or less, preferably 3 It is a range of not more than mass%, more preferably not more than 2 mass%. Below this range, the coatability may be significantly reduced. If it exceeds, the proportion of the active material in the positive electrode active material layer may be reduced, which may cause a problem of a decrease in battery capacity or an increase in resistance between the positive electrode active materials.
上記導電材としては、公知の導電材を任意に用いることができる。具体例としては、銅、ニッケル等の金属材料、天然黒鉛、人造黒鉛等の黒鉛（グラファイト）、アセチレンブラック等のカーボンブラック、ニードルコークス等の無定形炭素等の炭素材料等が挙げられる。なお、これらは、１種を単独で用いてもよく、２種以上を任意の組み合わせ及び比率で併用してもよい。導電材は、正極活物質層中に、通常０．０１質量％以上、好ましくは０．１質量％以上、より好ましくは１質量％以上であり、また、通常５０質量％以下、好ましくは３０質量％以下、より好ましくは１５質量％以下含有するように用いられる。含有量がこの範囲よりも低いと導電性が不十分となる場合がある。逆に、含有量がこの範囲よりも高いと電池容量が低下する場合がある。 A well-known conductive material can be used arbitrarily as said conductive material. Specific examples thereof include metal materials such as copper and nickel, graphites such as natural graphite and artificial graphite, carbon blacks such as acetylene black, and carbon materials such as amorphous carbon such as needle coke. In addition, these may be used individually by 1 type and may use 2 or more types together by arbitrary combinations and a ratio. The conductive material is usually 0.01% by mass or more, preferably 0.1% by mass or more, more preferably 1% by mass or more, and usually 50% by mass or less, preferably 30% by mass, in the positive electrode active material layer. % Or less, more preferably 15% by mass or less. If the content is lower than this range, the conductivity may be insufficient. Conversely, if the content is higher than this range, the battery capacity may decrease.
上記正極集電体は、高温保存特性がより一層改善することから、弁金属又はその合金で構成されていることが好ましい。上記弁金属としては、アルミニウム、チタン、タンタル、クロム等が挙げられる。上記正極集電体は、アルミニウム又はアルミニウムの合金で構成されていることがより好ましい。 The positive electrode current collector is preferably made of a valve metal or an alloy thereof in order to further improve the high temperature storage characteristics. As said valve metal, aluminum, titanium, a tantalum, chromium etc. are mentioned. More preferably, the positive electrode current collector is made of aluminum or an alloy of aluminum.
上記リチウムイオン二次電池は、高温保存特性がより一層改善することから、上記正極集電体と電気的に接続されている部分のうち電解液と接触する部分についても、弁金属又はその合金で構成されていることが好ましい。特に、電池外装ケース、及び、上記電池外装ケースに収容されるリード線や安全弁等のうち正極集電体と電気的に接続されていて、かつ非水電解液と接触する部分は、弁金属又はその合金で構成することが好ましい。弁金属又はその合金により被覆したステンレスを使用してもよい。 The lithium ion secondary battery is further improved in high temperature storage characteristics, so that the part in contact with the electrolytic solution among the parts electrically connected to the positive electrode current collector is also a valve metal or an alloy thereof. It is preferable that it is comprised. In particular, of the battery case, and the lead wire and the safety valve accommodated in the battery case, a portion electrically connected to the positive electrode current collector and in contact with the non-aqueous electrolyte is a valve metal or It is preferable to comprise the alloy. Stainless steel coated with valve metal or its alloy may be used.
上記正極の製造方法は、上述したとおりであり、例えば、上記正極活物質に、上述した結着剤、増粘剤、導電材、溶媒等を加えてスラリー状の正極合剤とし、これを上記正極集電体に塗布し、乾燥した後にプレスして高密度化する方法が挙げられる。 The method for producing the positive electrode is as described above. For example, the above-mentioned binder, thickener, conductive material, solvent and the like are added to the above-mentioned positive electrode active material to obtain a slurry-like positive electrode mixture, There is a method of applying a positive electrode current collector, drying and pressing to increase the density.
上記負極の構成は上述したとおりである。 The configuration of the negative electrode is as described above.
上記電気二重層キャパシタは、正極、負極、及び、上述の電解液を備えていてよい。
上記電気二重層キャパシタでは、正極及び負極の少なくとも一方は分極性電極であり、分極性電極及び非分極性電極としては特開平９－７８９６号公報に詳しく記載されている以下の電極が使用できる。 The electric double layer capacitor may include a positive electrode, a negative electrode, and the above-described electrolytic solution.
In the electric double layer capacitor, at least one of the positive electrode and the negative electrode is a polarizable electrode, and the following electrodes described in detail in JP-A-9-7896 can be used as the polarizable electrode and the nonpolarizable electrode.
本発明で用いる活性炭を主体とする分極性電極は、好ましくは大比表面積の不活性炭と電子伝導性を付与するカーボンブラック等の導電剤とを含むものである。分極性電極は種々の方法で形成することができる。例えば、活性炭粉末とカーボンブラックとフェノール系樹脂を混合し、プレス成形後不活性ガス雰囲気中及び水蒸気雰囲気中で焼成、賦活することにより、活性炭とカーボンブラックからなる分極性電極を形成できる。好ましくは、この分極性電極は集電体と導電性接着剤等で接合する。 The polarizable electrode mainly composed of activated carbon used in the present invention preferably contains non-activated carbon having a large specific surface area and a conductive agent such as carbon black which imparts electron conductivity. The polarizable electrode can be formed in various ways. For example, a polarizable electrode composed of activated carbon and carbon black can be formed by mixing activated carbon powder, carbon black and a phenolic resin, and after press molding, firing and firing in an inert gas atmosphere and a water vapor atmosphere. Preferably, the polarizable electrode is joined to the current collector with a conductive adhesive or the like.
また、活性炭粉末、カーボンブラック及び結合剤をアルコールの存在下で混練してシート状に成形し、乾燥して分極性電極とすることもできる。この結合剤には、例えばポリテトラフルオロエチレンが用いられる。また、活性炭粉末、カーボンブラック、結合剤及び溶媒を混合してスラリーとし、このスラリーを集電体の金属箔にコートし、乾燥して集電体と一体化された分極性電極とすることもできる。 Alternatively, activated carbon powder, carbon black and a binder may be kneaded in the presence of alcohol to form a sheet, which may be dried to form a polarizable electrode. For example, polytetrafluoroethylene is used as the binder. Alternatively, activated carbon powder, carbon black, a binder and a solvent are mixed to form a slurry, and the slurry is coated on a metal foil of a current collector and dried to form a polarizable electrode integrated with the current collector. it can.
活性炭を主体とする分極性電極を両極に用いて電気二重層キャパシタとしてもよいが、片側に非分極性電極を用いる構成、例えば、金属酸化物等の電池活物質を主体とする正極と、活性炭を主体とする分極性電極の負極とを組合せた構成、リチウムイオンを可逆的に吸蔵、離脱しうる炭素材料を主体とする負極、又はリチウム金属やリチウム合金の負極と、活性炭を主体とする分極性の正極とを組合せた構成も可能である。 Although a polarizable electrode mainly composed of activated carbon may be used as an electrical double layer capacitor for both electrodes, a nonpolarizable electrode may be used on one side, for example, a positive electrode mainly composed of a battery active material such as metal oxide, and activated carbon A combination of the polarizable electrode and the negative electrode of the main component, the negative electrode mainly of the carbon material capable of reversibly absorbing and desorbing lithium ions, or the negative electrode of lithium metal or lithium alloy and the active carbon as the main component A configuration combining a positive pole is also possible.
また、活性炭に代えて又は併用して、カーボンブラック、グラファイト、膨張黒鉛、ポーラスカーボン、カーボンナノチューブ、カーボンナノホーン、ケッチェンブラック等の炭素質材料を用いてもよい。 Also, in place of or in combination with activated carbon, a carbonaceous material such as carbon black, graphite, expanded graphite, porous carbon, carbon nanotube, carbon nanohorn, ketjen black may be used.
非分極性電極としては、好ましくはリチウムイオンを可逆的に吸蔵、離脱しうる炭素材料を主体とするものとし、この炭素材料にリチウムイオンを吸蔵させたものを電極に使用する。この場合、電解質にはリチウム塩が使用される。この構成の電気二重層キャパシタによれば、更に高い４Ｖを超える耐電圧が得られる。 As the non-polarizable electrode, preferably, a carbon material capable of reversibly absorbing and desorbing lithium ions is mainly used, and the carbon material in which lithium ions are occluded is used for the electrode. In this case, a lithium salt is used as the electrolyte. According to the electric double layer capacitor of this configuration, a further higher withstand voltage of 4 V can be obtained.
電極の作製におけるスラリーの調製に用いる溶媒は結合剤を溶解するものが好ましく、結合剤の種類に合わせ、Ｎ－メチルピロリドン、ジメチルホルムアミド、トルエン、キシレン、イソホロン、メチルエチルケトン、酢酸エチル、酢酸メチル、フタル酸ジメチル、エタノール、メタノール、ブタノール又は水が適宜選択される。 The solvent used for the preparation of the slurry in the preparation of the electrode is preferably one which dissolves the binder, and depending on the kind of binder, N-methylpyrrolidone, dimethylformamide, toluene, xylene, isophorone, methyl ethyl ketone, ethyl acetate, methyl acetate, phthalate The acid dimethyl, ethanol, methanol, butanol or water are chosen accordingly.
分極性電極に用いる活性炭としては、フェノール樹脂系活性炭、やしがら系活性炭、石油コークス系活性炭等がある。これらのうち大きい容量を得られる点で石油コークス系活性炭又はフェノール樹脂系活性炭を使用するのが好ましい。また、活性炭の賦活処理法には、水蒸気賦活処理法、溶融ＫＯＨ賦活処理法等があり、より大きな容量が得られる点で溶融ＫＯＨ賦活処理法による活性炭を使用するのが好ましい。 Examples of the activated carbon used for the polarizable electrode include phenol resin-based activated carbon, coconut-based activated carbon, and petroleum coke-based activated carbon. Among these, it is preferable to use petroleum coke-based activated carbon or phenol resin-based activated carbon in that a large capacity can be obtained. Further, the activation treatment method of activated carbon includes a steam activation treatment method, a molten KOH activation treatment method, and the like, and it is preferable to use activated carbon by the molten KOH activation treatment method in that a larger capacity can be obtained.
分極性電極に用いる好ましい導電剤としては、カーボンブラック、ケッチェンブラック、アセチレンブラック、天然黒鉛、人造黒鉛、金属ファイバ、導電性酸化チタン、酸化ルテニウムが挙げられる。分極性電極に使用するカーボンブラック等の導電剤の混合量は、良好な導電性（低い内部抵抗）を得るように、また多すぎると製品の容量が減るため、活性炭との合計量中１～５０質量％とするのが好ましい。 Preferable conductive agents used for the polarizable electrode include carbon black, ketjen black, acetylene black, natural graphite, artificial graphite, metal fibers, conductive titanium oxide and ruthenium oxide. The mixing amount of a conductive agent such as carbon black used for the polarizable electrode is 1 to 10% of the total amount with the activated carbon to obtain good conductivity (low internal resistance) or reduce the capacity of the product when too large. It is preferable to set it as 50 mass%.
また、分極性電極に用いる活性炭としては、大容量で低内部抵抗の電気二重層キャパシタが得られるように、平均粒径が２０μｍ以下で比表面積が１５００～３０００ｍ２／ｇの活性炭を使用するのが好ましい。また、リチウムイオンを可逆的に吸蔵、離脱しうる炭素材料を主体とする電極を構成するための好ましい炭素材料としては、天然黒鉛、人造黒鉛、黒鉛化メソカーボン小球体、黒鉛化ウィスカ、気層成長炭素繊維、フルフリルアルコール樹脂の焼成品又はノボラック樹脂の焼成品が挙げられる。 In addition, as activated carbon used for the polarizable electrode, activated carbon having an average particle diameter of 20 μm or less and a specific surface area of 1500 to 3000 m 2 / g is used so that a large capacity and low internal resistance electric double layer capacitor can be obtained. Is preferred. In addition, as preferable carbon materials for constituting an electrode composed mainly of a carbon material capable of reversibly absorbing and desorbing lithium ions, natural graphite, artificial graphite, graphitized mesocarbon small spheres, graphitized whiskers, gas layer A grown carbon fiber, a baked product of furfuryl alcohol resin or a baked product of novolak resin may be mentioned.
集電体は化学的、電気化学的に耐食性のあるものであればよい。活性炭を主体とする分極性電極の集電体としては、ステンレス、アルミニウム、チタン又はタンタルが好ましく使用できる。これらのうち、ステンレス又はアルミニウムが、得られる電気二重層キャパシタの特性と価格の両面において特に好ましい材料である。リチウムイオンを可逆的に吸蔵、離脱しうる炭素材料を主体とする電極の集電体としては、好ましくはステンレス、銅又はニッケルが使用される。 The current collector may be any one that is chemically and electrochemically corrosion resistant. Stainless steel, aluminum, titanium or tantalum can be preferably used as the current collector of the polarizable electrode mainly composed of activated carbon. Among these, stainless steel or aluminum is a particularly preferable material in terms of both the properties and the cost of the obtained electric double layer capacitor. Preferably, stainless steel, copper or nickel is used as a current collector of an electrode composed mainly of a carbon material capable of reversibly absorbing and desorbing lithium ions.
また、リチウムイオンを可逆的に吸蔵、離脱しうる炭素材料にあらかじめリチウムイオンを吸蔵させるには、（１）粉末状のリチウムを、リチウムイオンを可逆的に吸蔵、離脱しうる炭素材料に混ぜておく方法、（２）リチウムイオンを可逆的に吸蔵、離脱しうる炭素材料と結合剤により形成された電極上にリチウム箔を載せ、電極と電気的に接触させた状態で、この電極をリチウム塩を溶かした電解液中に浸漬することによりリチウムをイオン化させ、リチウムイオンを炭素材料中に取り込ませる方法、（３）リチウムイオンを可逆的に吸蔵、離脱しうる炭素材料と結合剤により形成された電極をマイナス側に置き、リチウム金属をプラス側に置いてリチウム塩を電解質とする非水系電解液中に浸漬し、電流を流して電気化学的に炭素材料中にリチウムをイオン化した状態で取り込ませる方法がある。 In addition, in order to occlude lithium ions in advance in a carbon material capable of reversibly absorbing and desorbing lithium ions, (1) a powdery lithium is mixed with a carbon material capable of reversibly absorbing and desorbing lithium ions (2) A lithium foil is placed on an electrode formed of a carbon material capable of reversibly absorbing and desorbing lithium ions and a binder, and the electrode is a lithium salt in a state of being in electrical contact with the electrode. Lithium is ionized by immersing in a molten electrolyte and lithium ions are incorporated into the carbon material, (3) formed by the carbon material and the binder capable of reversibly absorbing and desorbing lithium ions The electrode is placed on the negative side, lithium metal is placed on the positive side, and it is immersed in a non-aqueous electrolyte solution using lithium salt as the electrolyte, and a carbon material is electrochemically supplied by passing an electric current. A method of incorporating in a state in which lithium has been ionized.
電気二重層キャパシタとしては、巻回型電気二重層キャパシタ、ラミネート型電気二重層キャパシタ、コイン型電気二重層キャパシタ等が一般に知られており、上記電気二重層キャパシタもこれらの形式とすることができる。 As the electric double layer capacitor, a wound type electric double layer capacitor, a laminate type electric double layer capacitor, a coin type electric double layer capacitor and the like are generally known, and the above electric double layer capacitor can also be in these types. .
例えば巻回型電気二重層キャパシタは、集電体と電極層の積層体（電極）からなる正極及び負極を、セパレータを介して巻回して巻回素子を作製し、この巻回素子をアルミニウム製等のケースに入れ、電解液、好ましくは非水系電解液を満たしたのち、ゴム製の封口体で封止して密封することにより組み立てられる。 For example, in a wound type electric double layer capacitor, a positive electrode and a negative electrode composed of a laminate (electrode) of a current collector and an electrode layer are wound via a separator to produce a wound element, and this wound element is made of aluminum Etc., filled with an electrolytic solution, preferably a non-aqueous electrolytic solution, and then sealed by sealing with a rubber sealing body.
セパレータとしては、従来公知の材料と構成のものが使用できる。例えば、ポリエチレン多孔質膜、ポリテトラフルオロエチレン、ポリプロピレン繊維やガラス繊維、セルロース繊維の不織布等が挙げられる。 As the separator, those of conventionally known materials and constitutions can be used. For example, polyethylene porous membrane, polytetrafluoroethylene, polypropylene fiber or glass fiber, non-woven fabric of cellulose fiber, etc. may be mentioned.
また、公知の方法により、電解液とセパレータを介してシート状の正極及び負極を積層したラミネート型電気二重層キャパシタや、ガスケットで固定して電解液とセパレータを介して正極及び負極をコイン型に構成したコイン型電気二重層キャパシタとすることもできる。 In addition, a laminate type electric double layer capacitor in which sheet-like positive and negative electrodes are stacked via an electrolytic solution and a separator by a known method, or a gasket is fixed to make the positive and negative electrodes coin-shaped through the electrolytic solution and the separator. A coin-type electric double layer capacitor can also be configured.
本発明の電解液は、ハイブリッド自動車用や分散電源用の大型リチウムイオン二次電池用や、電気二重層キャパシタ用の電解液として有用である。 The electrolytic solution of the present invention is useful as an electrolytic solution for a large-sized lithium ion secondary battery for a hybrid automobile or for a dispersed power source, and for an electric double layer capacitor.
次に本発明を実施例を挙げて説明するが、本発明はかかる実施例のみに限定されるものではない。 EXAMPLES The present invention will next be described by way of examples, which should not be construed as limiting the invention thereto.
（電解液の調製）
実施例１～８
エチレンカーボネート（ＥＣ）とエチルメチルカーボネート（ＥＭＣ）の混合物（体積比３０：７０）にＬｉＰＦ６を１．０モル／リットルの濃度となるように添加し、基本電解液とした。更にこの電解液にメチルアリルオキサレートとジアリルオキサレートとジメチルオキサレートを表１に記載の含有量となるよう添加して非水電解液を得た。なお、各表中の各添加化合物の含有量は、最終的に得られる電解液に対する割合を示す。 (Preparation of electrolyte)
Examples 1 to 8
LiPF 6 was added to a mixture of ethylene carbonate (EC) and ethyl methyl carbonate (EMC) (volume ratio: 30:70) to a concentration of 1.0 mol / l to prepare a basic electrolyte. Further, methyl allyl oxalate, diallyl oxalate and dimethyl oxalate were added to this electrolytic solution to a content described in Table 1 to obtain a non-aqueous electrolytic solution. In addition, content of each addition compound in each table | surface shows the ratio with respect to the electrolyte solution finally obtained.
実施例９
実施例４において、メチルアリルオキサレートとジメチルオキサレートの代わりにエチルアリルオキサレートとジエチルオキサレートを添加して非水電解液を得た。 Example 9
In Example 4, ethyl allyl oxalate and diethyl oxalate were added instead of methyl allyl oxalate and dimethyl oxalate to obtain a non-aqueous electrolyte.
実施例１０
実施例４において、更にメチルアリルカーボネートを表１に記載の含有量となるよう添加して非水電解液を得た。 Example 10
In Example 4, methyl allyl carbonate was further added to a content described in Table 1 to obtain a non-aqueous electrolytic solution.
実施例１１
エチレンカーボネート（ＥＣ）とジメチルカーボネート（ＤＭＣ）の混合物（体積比３０：７０）にＬｉＰＦ６を１．０モル／リットルの濃度となるように添加し、基本電解液とした。更にこの電解液にメチルアリルオキサレートとジアリルオキサレートとジメチルオキサレートを表１に記載の含有量となるよう添加して非水電解液を得た。 Example 11
LiPF 6 was added to a mixture of ethylene carbonate (EC) and dimethyl carbonate (DMC) (volume ratio: 30:70) to a concentration of 1.0 mol / l to prepare a basic electrolyte. Further, methyl allyl oxalate, diallyl oxalate and dimethyl oxalate were added to this electrolytic solution to a content described in Table 1 to obtain a non-aqueous electrolytic solution.
実施例１２
エチレンカーボネート（ＥＣ）とプロピオン酸エチル（ＥＰ）の混合物（体積比３０：７０）にＬｉＰＦ６を１．０モル／リットルの濃度となるように添加し、基本電解液とした。更にこの電解液にメチルアリルオキサレートとジアリルオキサレートとジメチルオキサレートを表１に記載の含有量となるよう添加して非水電解液を得た。 Example 12
LiPF 6 was added to a mixture of ethylene carbonate (EC) and ethyl propionate (EP) (volume ratio: 30:70) to a concentration of 1.0 mol / l to prepare a basic electrolyte. Further, methyl allyl oxalate, diallyl oxalate and dimethyl oxalate were added to this electrolytic solution to a content described in Table 1 to obtain a non-aqueous electrolytic solution.
比較例１
実施例１において、メチルアリルオキサレートとジアリルオキサレートとジメチルオキサレートを添加せずに調製し、非水電解液を得た。 Comparative Example 1
In Example 1, preparation was made without addition of methyl allyl oxalate, diallyl oxalate and dimethyl oxalate to obtain a non-aqueous electrolytic solution.
比較例２
比較例１の電解液に、更にジエチルオキサレートを表１に記載の含有量となるよう添加して非水電解液を得た。 Comparative example 2
Further, diethyl oxalate was added to the electrolytic solution of Comparative Example 1 to a content described in Table 1 to obtain a non-aqueous electrolytic solution.
（アルミラミネート型リチウムイオン二次電池の作製）
［正極の作製］
正極活物質としてのＬｉ（Ｎｉ１／３Ｍｎ１／３Ｃｏ１／３）Ｏ２　９０質量％と、導電材としてのアセチレンブラック５質量％と、結着剤としてのポリフッ化ビニリデン（ＰＶｄＦ）５質量％とを、Ｎ－メチルピロリドン溶媒中で混合して、スラリー化した。得られたスラリーを、予め導電助剤を塗布した厚さ１５μｍのアルミ箔の片面に塗布して、乾燥し、プレス機にてロールプレスしたものを、活物質層のサイズとして幅５０ｍｍ、長さ３０ｍｍ、及び幅５ｍｍ、長さ９ｍｍの未塗工部を有する形状に切り出して正極とした。 (Fabrication of aluminum laminate type lithium ion secondary battery)
[Production of positive electrode]
90% by mass of Li (Ni 1/3 Mn 1/3 Co 1/3 ) O 2 as a positive electrode active material, 5% by mass of acetylene black as a conductive material, and polyvinylidene fluoride (PVdF) 5 as a binder Mass% was mixed in N-methyl pyrrolidone solvent and slurried. The obtained slurry is applied on one side of a 15 μm thick aluminum foil coated with a conductive aid in advance, dried, and roll-pressed with a press. The size of the active material layer is 50 mm wide and 50 mm long. It cut out to the shape which has an uncoated part of 30 mm and width 5 mm and length 9 mm, and was used as the positive electrode.
［負極の作製］
炭素質材料（グラファイト）９８質量部に、増粘剤及びバインダーとして、カルボキシメチルセルロースナトリウムの水性ディスパージョン（カルボキシメチルセルロースナトリウムの濃度１質量％）１質量部及びスチレン－ブタジエンゴムの水性ディスパージョン（スチレン－ブタジエンゴムの濃度５０質量％）１質量部を加え、ディスパーザーで混合してスラリー化した。得られたスラリーを厚さ１０μｍの銅箔に塗布して乾燥し、プレス機で圧延したものを、活物質層のサイズとして幅５２ｍｍ、長さ３２ｍｍ、及び幅５ｍｍ、長さ９ｍｍの未塗工部を有する形状に切り出して負極とした。 [Fabrication of negative electrode]
To 98 parts by mass of a carbonaceous material (graphite), 1 part by mass of an aqueous dispersion of carboxymethylcellulose sodium (concentration of 1% by mass of sodium carboxymethylcellulose) as a thickener and a binder, and an aqueous dispersion of styrene-butadiene rubber (styrene- 1 part by mass of a butadiene rubber concentration of 50% by mass) was added, mixed by a disperser and slurried. The obtained slurry is applied to a copper foil with a thickness of 10 μm, dried, and rolled with a press, and the size of the active material layer is 52 mm in width, 32 mm in length, and 5 mm in width, 9 mm in length. It cut out to the shape which has a part, and was set as the negative electrode.
［アルミラミネートセルの作製］
上記の正極を厚さ２０μｍの微孔性ポリエチレンフィルム（セパレータ）を介して正極と負極を対向させ、上記で得られた非水電解液を注入し、上記非水電解液がセパレータ等に充分に浸透した後、封止し予備充電、エージングを行い、リチウムイオン二次電池を作製した。 [Production of aluminum laminated cell]
The positive electrode and the negative electrode are made to face each other through a microporous polyethylene film (separator) having a thickness of 20 μm and the non-aqueous electrolytic solution obtained above is injected, and the non-aqueous electrolytic solution is sufficiently used as a separator. After penetration, the battery was sealed, pre-charged and aged to prepare a lithium ion secondary battery.
（電池特性の測定）
［初期特性評価］
上記で製造したリチウムイオン二次電池を、板で挟み加圧した状態で、２５℃において、０．２Ｃに相当する定電流で４．２Ｖまで充電した後、０．２Ｃの定電流で３．０Ｖまで放電した。これを２サイクル行って電池を安定させ、３サイクル目は、０．２Ｃの定電流で４．２Ｖまで充電後、４．２Ｖの定電圧で電流値が０．０５Ｃになるまで充電を実施し、０．２Ｃの定電流で３．０Ｖまで放電した。その後、４サイクル目に０．２Ｃの定電流で４．２Ｖまで充電後、４．２Ｖの定電圧で電流値が０．０５Ｃになるまで充電を実施し、０．２Ｃの定電流で３．０Ｖまで放電し、初期放電容量を求めた。その後、０．２Ｃの定電流で４．２Ｖまで充電後、４．２Ｖの定電圧で電流値が０．０５Ｃになるまで充電を実施した。
ここで、１Ｃとは電池の基準容量を１時間で放電する電流値を表し、５Ｃとはその５倍の電流値を、０．１Ｃとはその１／１０の電流値を、また０．２Ｃとはその１／５の電流値を表す。 (Measurement of battery characteristics)
[Initial characterization]
The lithium ion secondary battery manufactured above is charged to 4.2 V at a constant current corresponding to 0.2 C at 25 ° C. in a state of sandwiching and pressing with a plate, and then 3. It discharged to 0V. This is done 2 cycles to stabilize the battery, and in the third cycle, after charging to 4.2 V with a constant current of 0.2 C, charge to a current value of 0.05 C with a constant voltage of 4.2 V And was discharged to 3.0 V with a constant current of 0.2C. Thereafter, in the fourth cycle, after charging to 4.2 V with a constant current of 0.2 C, charging is performed at a constant voltage of 4.2 V until the current value reaches 0.05 C, and 3. It discharged to 0 V and calculated | required initial stage discharge capacity. Thereafter, the battery was charged to 4.2 V with a constant current of 0.2 C and then charged to a current value of 0.05 C with a constant voltage of 4.2 V.
Here, 1 C represents a current value for discharging the reference capacity of the battery in one hour, 5 C represents a current value five times that of 0.1 C, and 1 C represents a current value 1/10 that of 0.2 C. Represents a current value of 1⁄5.
［高温保存試験］
初期特性評価が終了した二次電池を、８５℃３６時間の条件で高温保存した。次に、２５℃において０．５Ｃで３Ｖまで放電し、高温保存後の残存容量を測定し、下記式に基づき、容量維持率（％）を求めた。
（残存容量）／（初期放電容量）×１００＝容量維持率（％）
結果を表１に示す。 [High temperature storage test]
The secondary battery for which the initial characterization was completed was stored at 85 ° C. for 36 hours under high temperature. Next, the battery was discharged to 3 V at 0.5 ° C. at 25 ° C., the residual capacity after high temperature storage was measured, and the capacity retention rate (%) was determined based on the following equation.
(Remaining capacity) / (initial discharge capacity) × 100 = capacity maintenance rate (%)
The results are shown in Table 1.
［高温サイクル試験］
上記で製造したリチウムイオン二次電池を、板で挟み加圧した状態で、６０℃において、１Ｃに相当する電流で４．２Ｖまで定電流－定電圧充電（以下、ＣＣ／ＣＶ充電と表記する。）（０．１Ｃカット）した後、１Ｃの定電流で３Ｖまで放電し、これを１サイクルとして、３サイクル目の放電容量から初期放電容量を求めた。ここで、１Ｃとは電池の基準容量を１時間で放電する電流値を表わし、例えば、０．２Ｃとはその１／５の電流値を表わす。再度サイクルを行い、２００サイクル後の放電容量を測定した。初期放電容量に対する２００サイクル後の放電容量の割合を求め、これをサイクル容量維持率（％）とした。
（２００サイクル後の放電容量）÷（初期放電容量）×１００＝容量維持率（％）
結果を表１に示す。 [High temperature cycle test]
The lithium ion secondary battery manufactured above is charged with constant current to constant voltage up to 4.2 V at a current corresponding to 1 C at 60 ° C. in a state of being sandwiched and pressurized with a plate (hereinafter referred to as CC / CV charging) After (0.1 C cut), the battery was discharged to 3 V at a constant current of 1 C, and this was used as one cycle to obtain an initial discharge capacity from the discharge capacity at the third cycle. Here, 1 C represents a current value that discharges the reference capacity of the battery in one hour, and, for example, 0.2 C represents a current value of 1/5 thereof. The cycle was repeated again, and the discharge capacity after 200 cycles was measured. The ratio of the discharge capacity after 200 cycles to the initial discharge capacity was determined, and this was taken as the cycle capacity retention rate (%).
(Discharge capacity after 200 cycles) / (initial discharge capacity) x 100 = capacity retention rate (%)
The results are shown in Table 1.
（電解液の調製）
実施例１３
エチレンカーボネート（ＥＣ）とエチルメチルカーボネート（ＥＭＣ）の混合物（体積比３０：７０）にＬｉＰＦ６を１．２モル／リットルの濃度となるように添加して基本電解液とした。更にこの電解液にメチルアリルオキサレートとジアリルオキサレートとジメチルオキサレートとビニレンカーボネート（ＶＣ）を表２に記載の含有量となるよう添加して非水電解液を得た。 (Preparation of electrolyte)
Example 13
LiPF 6 was added to a mixture of ethylene carbonate (EC) and ethyl methyl carbonate (EMC) (volume ratio: 30:70) to a concentration of 1.2 mol / l to prepare a basic electrolyte. Further, methyl allyl oxalate, diallyl oxalate, dimethyl oxalate and vinylene carbonate (VC) were added to this electrolytic solution to the contents described in Table 2 to obtain a non-aqueous electrolytic solution.
実施例１４
実施例１３において、ＶＣの代わりにリチウムビスオキサラトボレート（ＬｉＢＯＢ）を表２に記載の含有量となるよう添加して非水電解液を得た。 Example 14
In Example 13, lithium bisoxalato borate (LiBOB) was added instead of VC to a content described in Table 2 to obtain a non-aqueous electrolytic solution.
実施例１５
実施例１３において、ＶＣの代わりにジフルオロリン酸リチウム（ＬｉＰＯ２Ｆ２）を表２に記載の含有量となるよう添加して非水電解液を得た。 Example 15
In Example 13, lithium difluorophosphate (LiPO 2 F 2 ) was added in place of VC to a content described in Table 2 to obtain a non-aqueous electrolytic solution.
実施例１６
実施例１３において、ＶＣの代わりにフルオロスルホン酸リチウム（ＦＳＯ３Ｌｉ）を表２に記載の含有量となるよう添加して非水電解液を得た。 Example 16
In Example 13, lithium fluorosulfonate (FSO 3 Li) was added in place of VC to a content described in Table 2 to obtain a non-aqueous electrolytic solution.
実施例１７
実施例１３において、ＶＣの代わりに硫酸エチルリチウム（Ｃ２Ｈ５ＯＳＯ３Ｌｉ）を表２に記載の含有量となるよう添加して非水電解液を得た。 Example 17
In Example 13, ethyl lithium sulfate (C 2 H 5 OSO 3 Li) was added in place of VC to a content described in Table 2 to obtain a non-aqueous electrolytic solution.
実施例１８
実施例１３において、ＶＣの代わりにフルオロエチレンカーボネート（ＦＥＣ）を表２に記載の含有量となるよう添加して非水電解液を得た。 Example 18
In Example 13, a non-aqueous electrolytic solution was obtained by adding fluoroethylene carbonate (FEC) to the content described in Table 2 instead of VC.
実施例１９
実施例１３において、ＶＣの代わりに４－（２，２，３，３，３－ペンタフルオロ－プロピル）－［１，３］ジオキソラン－２－オン（ＣＦ３ＣＦ２ＣＨ２－ＥＣ）を表２に記載の含有量となるよう添加して非水電解液を得た。 Example 19
In Example 13, 4- (2,2,3,3,3-pentafluoro-propyl)-[1,3] dioxolan-2-one (CF 3 CF 2 CH 2 -EC) is used in place of VC. It added so that it might become content described in 2, and the non-aqueous electrolyte was obtained.
実施例２０
実施例１３において、メチルアリルオキサレートとジメチルオキサレートの代わりにエチルアリルオキサレートとジエチルオキサレートを添加して非水電解液を得た。 Example 20
In Example 13, instead of methyl allyl oxalate and dimethyl oxalate, ethyl allyl oxalate and diethyl oxalate were added to obtain a non-aqueous electrolytic solution.
比較例３
実施例１３に記載の基本電解液を比較例３の非水電解液とした。 Comparative example 3
The basic electrolyte described in Example 13 was used as the non-aqueous electrolyte of Comparative Example 3.
比較例４
比較例３において、ジエチルオキサレートとＶＣとを表２に記載の含有量となるよう添加して非水電解液を得た。 Comparative example 4
In Comparative Example 3, diethyl oxalate and VC were added to the contents described in Table 2 to obtain a non-aqueous electrolytic solution.
比較例５
比較例３において、ジ（２－プロピニル）オキサレートとＶＣとを表２に記載の含有量となるよう添加して非水電解液を得た。 Comparative example 5
In Comparative Example 3, di (2-propynyl) oxalate and VC were added to the contents described in Table 2 to obtain a non-aqueous electrolytic solution.
比較例６
比較例３において、ジアリルオキサレートとＶＣとを表２に記載の含有量となるよう添加して非水電解液を得た。 Comparative example 6
In Comparative Example 3, diallyl oxalate and VC were added to the contents described in Table 2 to obtain a non-aqueous electrolytic solution.
比較例７
比較例３において、メチルアリルオキサレートとＬｉＰＯ２Ｆ２とを表２に記載の含有量となるよう添加して非水電解液を得た。 Comparative example 7
In Comparative Example 3, methyl allyl oxalate and LiPO 2 F 2 were added to the contents described in Table 2 to obtain a non-aqueous electrolytic solution.
比較例８
比較例３において、エチルアリルオキサレートとＬｉＰＯ２Ｆ２とを表２に記載の含有量となるよう添加して非水電解液を得た。 Comparative Example 8
In Comparative Example 3, ethyl allyl oxalate and LiPO 2 F 2 were added to the contents described in Table 2 to obtain a non-aqueous electrolytic solution.
（アルミラミネート型リチウムイオン二次電池の作製）
実施例１３～２０及び比較例３～８に記載の非水電解液を用いる他は、実施例１と同様にして、リチウムイオン二次電池を作製した。 (Fabrication of aluminum laminate type lithium ion secondary battery)
A lithium ion secondary battery was produced in the same manner as in Example 1 except that the non-aqueous electrolytes described in Examples 13 to 20 and Comparative Examples 3 to 8 were used.
（電池特性の測定）
［初期特性評価］
上記で製造したリチウムイオン二次電池を、板で挟み加圧した状態で、２５℃において、０．２Ｃに相当する定電流で４．２Ｖまで充電した後、０．２Ｃの定電流で３．０Ｖまで放電した。これを２サイクル行って電池を安定させ、３サイクル目は、０．２Ｃの定電流で４．２Ｖまで充電後、４．２Ｖの定電圧で電流値が０．０５Ｃになるまで充電を実施し、０．２Ｃの定電流で３．０Ｖまで放電した。その後、４サイクル目に０．２Ｃの定電流で４．２Ｖまで充電後、４．２Ｖの定電圧で電流値が０．０５Ｃになるまで充電を実施し、０．２Ｃの定電流で３．０Ｖまで放電し、初期放電容量を求めた。その後、０．２Ｃの定電流で４．２Ｖまで充電後、４．２Ｖの定電圧で電流値が０．０５Ｃになるまで充電を実施した。 (Measurement of battery characteristics)
[Initial characterization]
The lithium ion secondary battery manufactured above is charged to 4.2 V at a constant current corresponding to 0.2 C at 25 ° C. in a state of sandwiching and pressing with a plate, and then 3. It discharged to 0V. This is done 2 cycles to stabilize the battery, and in the third cycle, after charging to 4.2 V with a constant current of 0.2 C, charge to a current value of 0.05 C with a constant voltage of 4.2 V And was discharged to 3.0 V with a constant current of 0.2C. Thereafter, in the fourth cycle, after charging to 4.2 V with a constant current of 0.2 C, charging is performed at a constant voltage of 4.2 V until the current value reaches 0.05 C, and 3. It discharged to 0 V and calculated | required initial stage discharge capacity. Thereafter, the battery was charged to 4.2 V with a constant current of 0.2 C and then charged to a current value of 0.05 C with a constant voltage of 4.2 V.
［高温保存試験］
初期特性評価が終了した二次電池を、８５℃３６時間の条件で高温保存した。電池を十分に冷却させた後、アルキメデス法により体積を測定し、保存前後の体積変化から発生したガス量を求めた。次に、２５℃において０．５Ｃで３Ｖまで放電し、高温保存後の残存容量を測定し、下記式に基づき、容量維持率（％）を求めた。
（残存容量）／（初期放電容量）×１００＝容量維持率（％）
結果を表２に示す。 [High temperature storage test]
The secondary battery for which the initial characterization was completed was stored at 85 ° C. for 36 hours under high temperature. After the battery was sufficiently cooled, the volume was measured by the Archimedes method, and the amount of generated gas was determined from the volume change before and after storage. Next, the battery was discharged to 3 V at 0.5 ° C. at 25 ° C., the residual capacity after high temperature storage was measured, and the capacity retention rate (%) was determined based on the following equation.
(Remaining capacity) / (initial discharge capacity) × 100 = capacity maintenance rate (%)
The results are shown in Table 2.
［高温サイクル試験］
上記で製造したリチウムイオン二次電池を、板で挟み加圧した状態で、６０℃において、１Ｃに相当する電流で４．２Ｖまで定電流－定電圧充電（以下、ＣＣ／ＣＶ充電と表記する。）（０．１Ｃカット）した後、１Ｃの定電流で３Ｖまで放電し、これを１サイクルとして、３サイクル目の放電容量から初期放電容量を求めた。ここで、１Ｃとは電池の基準容量を１時間で放電する電流値を表わし、例えば、０．２Ｃとはその１／５の電流値を表わす。再度サイクルを行い、２００サイクル後の放電容量を測定した。初期放電容量に対する２００サイクル後の放電容量の割合を求め、これをサイクル容量維持率（％）とした。
（２００サイクル後の放電容量）÷（初期放電容量）×１００＝容量維持率（％）
結果を表２に示す。 [High temperature cycle test]
The lithium ion secondary battery manufactured above is charged with constant current to constant voltage up to 4.2 V at a current corresponding to 1 C at 60 ° C. in a state of being sandwiched and pressurized with a plate (hereinafter referred to as CC / CV charging) After (0.1 C cut), the battery was discharged to 3 V at a constant current of 1 C, and this was used as one cycle to obtain an initial discharge capacity from the discharge capacity at the third cycle. Here, 1 C represents a current value that discharges the reference capacity of the battery in one hour, and, for example, 0.2 C represents a current value of 1/5 thereof. The cycle was repeated again, and the discharge capacity after 200 cycles was measured. The ratio of the discharge capacity after 200 cycles to the initial discharge capacity was determined, and this was taken as the cycle capacity retention rate (%).
(Discharge capacity after 200 cycles) / (initial discharge capacity) x 100 = capacity retention rate (%)
The results are shown in Table 2.
（電解液の調製）
実施例２１
トリフルオロプロピレンカーボネートとメチル　２，２，２－トリフルオロエチルカーボネートの混合物（体積比３０：７０）にＬｉＰＦ６を１．０モル／リットルの濃度となるように添加して基本電解液とした。更にこの電解液にメチルアリルオキサレートとジアリルオキサレートとジメチルオキサレートを表３に記載の含有量となるよう添加して非水電解液を得た。 (Preparation of electrolyte)
Example 21
LiPF 6 was added to a mixture of trifluoropropylene carbonate and methyl 2,2,2-trifluoroethyl carbonate (volume ratio: 30:70) to a concentration of 1.0 mol / l to prepare a basic electrolyte. Further, methyl allyl oxalate, diallyl oxalate and dimethyl oxalate were added to this electrolytic solution to a content described in Table 3 to obtain a non-aqueous electrolytic solution.
実施例２２
トリフルオロプロピレンカーボネートとメチルジフルオロアセテートの混合物（体積比３０：７０）にＬｉＰＦ６を１．０モル／リットルの濃度となるように添加して基本電解液とした。更にこの電解液にメチルアリルオキサレートとジアリルオキサレートとジメチルオキサレートを表３に記載の含有量となるよう添加して非水電解液を得た。 Example 22
LiPF 6 was added to a mixture of trifluoropropylene carbonate and methyl difluoroacetate (volume ratio 30:70) to a concentration of 1.0 mol / l to prepare a basic electrolyte. Further, methyl allyl oxalate, diallyl oxalate and dimethyl oxalate were added to this electrolytic solution to a content described in Table 3 to obtain a non-aqueous electrolytic solution.
実施例２３
フルオロエチレンカーボネート（ＦＥＣ）とメチル　２，２，２－トリフルオロエチルカーボネートの混合物（体積比３０：７０）にＬｉＰＦ６を１．０モル／リットルの濃度となるように添加して基本電解液とした。更にこの電解液にメチルアリルオキサレートとジアリルオキサレートとジメチルオキサレートを表３に記載の含有量となるよう添加して非水電解液を得た。 Example 23
LiPF 6 is added to a mixture of fluoroethylene carbonate (FEC) and methyl 2,2,2-trifluoroethyl carbonate (volume ratio 30:70) to a concentration of 1.0 mol / l to obtain a basic electrolyte did. Further, methyl allyl oxalate, diallyl oxalate and dimethyl oxalate were added to this electrolytic solution to a content described in Table 3 to obtain a non-aqueous electrolytic solution.
実施例２４
フルオロエチレンカーボネート（ＦＥＣ）とメチルジフルオロアセテートの混合物（体積比３０：７０）にＬｉＰＦ６を１．０モル／リットルの濃度となるように添加して基本電解液とした。更にこの電解液にメチルアリルオキサレートとジアリルオキサレートとジメチルオキサレートを表３に記載の含有量となるよう添加して非水電解液を得た。 Example 24
LiPF 6 was added to a mixture of fluoroethylene carbonate (FEC) and methyl difluoroacetate (volume ratio 30:70) to a concentration of 1.0 mol / l to prepare a basic electrolyte. Further, methyl allyl oxalate, diallyl oxalate and dimethyl oxalate were added to this electrolytic solution to a content described in Table 3 to obtain a non-aqueous electrolytic solution.
実施例２５
フルオロエチレンカーボネート（ＦＥＣ）とメチル３，３，３－トリフルオロプロピオネートの混合物（体積比３０：７０）にＬｉＰＦ６を１．０モル／リットルの濃度となるように添加して基本電解液とした。更にこの電解液にメチルアリルオキサレートとジアリルオキサレートとジメチルオキサレートを表３に記載の含有量となるよう添加して非水電解液を得た。 Example 25
Add LiPF 6 to a mixture of fluoroethylene carbonate (FEC) and methyl 3,3,3-trifluoropropionate (volume ratio 30:70) to give a concentration of 1.0 mol / l, and did. Further, methyl allyl oxalate, diallyl oxalate and dimethyl oxalate were added to this electrolytic solution to a content described in Table 3 to obtain a non-aqueous electrolytic solution.
実施例２６
実施例２４において、メチルアリルオキサレートとジメチルオキサレートの代わりにエチルアリルオキサレートとジエチルオキサレートを添加して非水電解液を得た。 Example 26
In Example 24, instead of methyl allyl oxalate and dimethyl oxalate, ethyl allyl oxalate and diethyl oxalate were added to obtain a non-aqueous electrolytic solution.
比較例９
実施例２１に記載の基本電解液を比較例９の非水電解液とした。 Comparative Example 9
The basic electrolyte described in Example 21 was used as the non-aqueous electrolyte of Comparative Example 9.
比較例１０
実施例２２に記載の基本電解液を比較例１０の非水電解液とした。 Comparative example 10
The base electrolyte described in Example 22 was used as the non-aqueous electrolyte of Comparative Example 10.
比較例１１
実施例２３に記載の基本電解液を比較例１１の非水電解液とした。 Comparative example 11
The basic electrolyte described in Example 23 was used as the non-aqueous electrolyte of Comparative Example 11.
比較例１２
実施例２４に記載の基本電解液を比較例１２の非水電解液とした。 Comparative Example 12
The basic electrolyte described in Example 24 was used as the non-aqueous electrolyte of Comparative Example 12.
比較例１３
実施例２５に記載の基本電解液を比較例１３の非水電解液とした。 Comparative Example 13
The basic electrolyte described in Example 25 was used as the non-aqueous electrolyte of Comparative Example 13.
比較例１４
比較例９に記載の電解液において、ジメチルオキサレートを表３に記載の含有量となるよう添加して非水電解液を得た。 Comparative Example 14
In the electrolytic solution described in Comparative Example 9, dimethyl oxalate was added to a content described in Table 3 to obtain a non-aqueous electrolytic solution.
比較例１５
比較例１１に記載の電解液において、ジメチルオキサレートを表３に記載の含有量となるよう添加して非水電解液を得た。 Comparative example 15
In the electrolytic solution described in Comparative Example 11, dimethyl oxalate was added to a content described in Table 3 to obtain a non-aqueous electrolytic solution.
（アルミラミネート型リチウムイオン二次電池の作製）
実施例２１～２６及び比較例９～１５に記載の非水電解液を用いる他は、実施例１と同様にして、リチウムイオン二次電池を作製した。 (Fabrication of aluminum laminate type lithium ion secondary battery)
A lithium ion secondary battery was produced in the same manner as in Example 1 except that the non-aqueous electrolytes described in Examples 21 to 26 and Comparative Examples 9 to 15 were used.
（電池特性の測定）
［高温サイクル特性試験］
上記で製造したリチウムイオン二次電池を、板で挟み加圧した状態で、６０℃において、１Ｃに相当する電流で４．３５Ｖまで定電流－定電圧充電（以下、ＣＣ／ＣＶ充電と表記する。）（０．１Ｃカット）した後、１Ｃの定電流で３Ｖまで放電し、これを１サイクルとして、３サイクル目の放電容量から初期放電容量を求めた。ここで、１Ｃとは電池の基準容量を１時間で放電する電流値を表わし、例えば、０．２Ｃとはその１／５の電流値を表わす。再度サイクルを行い、２００サイクル後の放電容量を測定した。初期放電容量に対する２００サイクル後の放電容量の割合を求め、これをサイクル容量維持率（％）とした。
（２００サイクル後の放電容量）÷（初期放電容量）×１００＝容量維持率（％）
結果を表３に示す。 (Measurement of battery characteristics)
[High temperature cycle characteristic test]
The lithium ion secondary battery manufactured above is charged with a constant current to constant voltage up to 4.35 V at a current corresponding to 1 C at 60 ° C. in a state of sandwiching and pressing with a plate (hereinafter referred to as CC / CV charging) After (0.1 C cut), the battery was discharged to 3 V at a constant current of 1 C, and this was used as one cycle to obtain an initial discharge capacity from the discharge capacity at the third cycle. Here, 1 C represents a current value that discharges the reference capacity of the battery in one hour, and, for example, 0.2 C represents a current value of 1/5 thereof. The cycle was repeated again, and the discharge capacity after 200 cycles was measured. The ratio of the discharge capacity after 200 cycles to the initial discharge capacity was determined, and this was taken as the cycle capacity retention rate (%).
(Discharge capacity after 200 cycles) / (initial discharge capacity) x 100 = capacity retention rate (%)
The results are shown in Table 3.
Figure JPOXMLDOC01-appb-T000090
Figure JPOXMLDOC01-appb-T000090
Figure JPOXMLDOC01-appb-T000091
Figure JPOXMLDOC01-appb-T000091
Figure JPOXMLDOC01-appb-T000092
Figure JPOXMLDOC01-appb-T000092

Claims (4)

  1. 下記一般式（１）で表される化合物（１）と、下記一般式（１１）で表される化合物（１１）及び下記一般式（１２）で表される化合物（１２）からなる群より選択される少なくとも１種とを含むことを特徴とする電解液。
    一般式（１）：
    Figure JPOXMLDOC01-appb-C000001
     （式中、Ｒ１０１は炭素数１～４のアルキル基であり、Ｒ１０２は炭素数２～４のアルケニル基である。）
    一般式（１１）：
    Figure JPOXMLDOC01-appb-C000002
     （式中、Ｒ１０１は前記と同じである。）
    一般式（１２）：
    Figure JPOXMLDOC01-appb-C000003
     （式中、Ｒ１０２は前記と同じである。）     Selected from the group consisting of a compound (1) represented by the following general formula (1), a compound (11) represented by the following general formula (11), and a compound (12) represented by the following general formula (12) And at least one of the following:
    General formula (1):
    Figure JPOXMLDOC01-appb-C000001
     (Wherein, R 101 is an alkyl group having 1 to 4 carbon atoms, and R 102 is an alkenyl group having 2 to 4 carbon atoms.)
    General formula (11):
    Figure JPOXMLDOC01-appb-C000002
     (Wherein, R 101 is the same as the above).
    General formula (12):
    Figure JPOXMLDOC01-appb-C000003
     (Wherein, R 102 is as defined above)
  2. 請求項１記載の電解液を備えることを特徴とする電気化学デバイス。 An electrochemical device comprising the electrolytic solution according to claim 1.
  3. 請求項１記載の電解液を備えることを特徴とするリチウムイオン二次電池。 A lithium ion secondary battery comprising the electrolytic solution according to claim 1.
  4. 請求項２記載の電気化学デバイス、又は、請求項３記載のリチウムイオン二次電池を備えることを特徴とするモジュール。

          A module comprising the electrochemical device according to claim 2 or the lithium ion secondary battery according to claim 3.

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2020246540A1 (en) * 2019-06-04 2020-12-10 三菱ケミカル株式会社 Non-aqueous electrolyte and non-aqueous electrolyte battery
US11594761B2 (en) 2017-11-09 2023-02-28 Daikin Industries, Ltd. Electrolytic solution, electrochemical device, lithium-ion secondary cell, and module

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09199172A (en) * 1996-01-18 1997-07-31 Sony Corp Nonaqueous electrolyte secondary battery
WO2005015677A1 (en) * 2003-08-11 2005-02-17 Ube Industries, Ltd. Lithium secondary cell and its nonaqueous electrolyte
JP2011238373A (en) * 2010-05-06 2011-11-24 Sony Corp Secondary battery, electrolytic solution for secondary battery, electric tool, electric vehicle, and power storage system
KR20150072188A (en) * 2013-12-19 2015-06-29 에스케이이노베이션 주식회사 Electrolyte for Lithium Secondary Battery and Lithium Secondary Battery Containing the Same

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09199172A (en) * 1996-01-18 1997-07-31 Sony Corp Nonaqueous electrolyte secondary battery
WO2005015677A1 (en) * 2003-08-11 2005-02-17 Ube Industries, Ltd. Lithium secondary cell and its nonaqueous electrolyte
JP2011238373A (en) * 2010-05-06 2011-11-24 Sony Corp Secondary battery, electrolytic solution for secondary battery, electric tool, electric vehicle, and power storage system
KR20150072188A (en) * 2013-12-19 2015-06-29 에스케이이노베이션 주식회사 Electrolyte for Lithium Secondary Battery and Lithium Secondary Battery Containing the Same

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11594761B2 (en) 2017-11-09 2023-02-28 Daikin Industries, Ltd. Electrolytic solution, electrochemical device, lithium-ion secondary cell, and module
WO2020246540A1 (en) * 2019-06-04 2020-12-10 三菱ケミカル株式会社 Non-aqueous electrolyte and non-aqueous electrolyte battery

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