Compounds, compositions, electrochemical devices, lithium-ion secondary batteries, and assemblies

Abstract

The present application provides a compound and a composition capable of achieving improvement in cycle characteristics, reduction in electric resistance, and suppression of gas generation of an electrochemical device, and an electrochemical device, a lithium-ion secondary battery, and a module having the composition as an electrolyte. A compound represented by the following general formula (1): Rf 1 -O-Rf 2 (1) wherein Rf 1 and Rf 2 are the same or different and are a fluoroalkenyl group having 2 to 4 carbon atoms.

Description

TECHNICAL FIELD

[0001] The present application relates to a compound, a composition, an electrochemical device, a lithium ion secondary battery, and a module. BACKGROUND

[0002] With the recent weight reduction and size reduction of electrical products, development of electrochemical devices such as lithium ion secondary batteries having high energy density has been promoted. In addition, as the application field of electrochemical devices such as lithium ion secondary batteries expands, improvement of characteristics is desired. In particular, in the future, in the case where lithium ion secondary batteries are used in vehicle applications, improvement of battery characteristics becomes increasingly important.

[0003] As a method for improving battery characteristics, for example, electrolytes containing specific ether compounds are described in Patent Literature 1 to Patent Literature 3.

[0004] PRIOR ART DOCUMENTS

[0005] PATENT LITERATURE

[0006] Patent Literature 1: Japanese Patent Application Laid-Open (JP-A) No. 9-97627

[0007] Patent Literature 2: Japanese Patent Application Laid-Open (JP-A) No. 11-26015

[0008] Patent Literature 3: Japanese Patent Application Laid-Open (JP-A) No. 2012-216539 SUMMARY

[0009] PROBLEMS TO BE SOLVED BY THE INVENTION

[0010] An object of the present application is to provide a compound and a composition capable of achieving improvement of cycle characteristics, reduction of resistance, and suppression of gas generation of an electrochemical device, and an electrochemical device, a lithium ion secondary battery, and a module each having the composition as an electrolyte.

[0011] TECHNICAL SOLUTION FOR SOLVING THE PROBLEMS

[0012] The present application relates to a compound represented by the following general formula (1):

[0013] Rf 1 -O-Rf 2 (1)

[0014] (in the formula, Rf 1 and Rf 2 are the same or different, and are fluoroalkenyl groups having 2 to 4 carbon atoms).

[0015] In the above formula (1), Rf 1 and Rf 2 are the same or different, and are preferably fluoroalkenyl groups having 2 to 3 carbon atoms.

[0016] The above compound is preferably an additive for an electrolyte solution.

[0017] The present application also relates to a composition containing the above compound.

[0018] The above composition preferably contains a compound represented by the following general formula (2):

[0019] Rf 3 -O-Rf 4 (2)

[0020] (in the formula, Rf 3 and Rf 4 are the same or different and are an alkyl group having 1 to 10 carbon atoms or a fluoroalkyl group having 1 to 10 carbon atoms; wherein at least one of Rf 3 and Rf 4 is a fluoroalkyl group).

[0021] The above composition is preferably an additive for an electrolyte solution.

[0022] The above composition is preferably an electrolyte solution.

[0023] The present application also relates to an electrochemical device provided with the above composition as an electrolyte solution.

[0024] The present application also relates to a lithium ion secondary battery provided with the above composition as an electrolyte solution.

[0025] The present application also relates to an assembly provided with the above electrochemical device or the above lithium ion secondary battery.

[0026] Effects of the Invention

[0027] According to the present application, it is possible to provide a compound and a composition that can achieve an improvement in cycle characteristics, a reduction in resistance, and an inhibition of gas generation of an electrochemical device, and an electrochemical device, a lithium ion secondary battery, and an assembly provided with the composition as an electrolyte solution. DETAILED DESCRIPTION

[0028] Hereinafter, the present application will be specifically described.

[0029] The present application relates to a compound represented by the following general formula (1) (hereinafter also referred to as compound (1)):

[0030] Rf 1 -O-Rf 2 (1)

[0031] (in the formula, Rf 1 and Rf 2 are the same or different and are a fluoroalkenyl group having 2 to 4 carbon atoms).

[0032] The compound (1) of the present application, which is a novel compound, can improve the cycle characteristics (e.g., capacity retention rate after cycling) and output characteristics (e.g., internal resistance) of an electrochemical device such as a lithium ion secondary battery, and can suppress gas generation at the time of cycling of the electrochemical device. It is presumed that these effects are due to the formation of a film of a decomposition product of the compound (1) on the electrode of the electrochemical device.

[0033] The compound (1) is represented by General Formula (1):

[0034] Rf 1 -O-Rf 2 (1)

[0035] In General Formula (1), Rf 1 and Rf 2 are each a fluoroalkenyl group having 2 to 4 carbon atoms. From the viewpoint of further improving the effects of improving cycle characteristics, reducing resistance, and suppressing gas generation, Rf 1 and Rf 2 are preferably a fluoroalkenyl group having 2 to 3 carbon atoms, and more preferably one is a fluoroalkenyl group having 2 carbon atoms and the other is a fluoroalkenyl group having 3 carbon atoms.

[0036] Rf 1 and Rf 2 may be linear or branched, and are preferably linear.

[0037] The fluorine content of the compound (1) is preferably 50 to 70% by mass. When the fluorine content is within this range, the balance between non-flammability and compatibility is particularly excellent. Furthermore, this is also preferable from the viewpoint of good oxidation resistance and safety.

[0038] The lower limit of the above-mentioned fluorine content is more preferably 53% by mass, and further preferably 57% by mass. The upper limit is more preferably 63% by mass, and further preferably 61% by mass.

[0039] In addition, the fluorine content of the compound (1) is a value calculated from the structural formula of the compound (1) by {(number of fluorine atoms x 19) / molecular weight of the compound (1)} x 100 (%).

[0040] Rf 1 and Rf 2CF2=CF-, CF2=CFCH2-, CF2=CFCFH-, CF2=CFCF2-, CF2=CHCH2CH2-, CF2=CFCH2CH2-, CF2=CFCFHCH2-, CF2=CFCF2CH2-, CF2=CFCF2CFH-, CF2=CFCF2CF2-, etc. Among them, Rf 1 and Rf 2 one of CF2=CF-, the other is CF2=CFCH2-. That is, compound (1) is particularly preferably CF2=CF-O-CH2CF=CF2.

[0041] Compound (1) can be used alone or in combination of two or more.

[0042] In addition, compound (1) can be used alone or as a composition by being mixed with other components. The present application also relates to a composition containing compound (1) (hereinafter, also referred to as the composition of the present application).

[0043] Compound (1) can be used as an additive for an electrolyte, a solvent for an electrolyte.

[0044] The composition of the present application, like compound (1), can be used as an additive for an electrolyte, a solvent for an electrolyte. Furthermore, the composition of the present application can itself be an electrolyte.

[0045] In the case where compound (1) is used as an additive for an electrolyte, the content of compound (1) with respect to the electrolyte is preferably 0.001 mass ppm or more, more preferably 0.1 mass ppm or more, further preferably 0.5 mass ppm or more, particularly preferably 1 mass ppm or more. In addition, the content of compound (1) is preferably 50,000 mass ppm or less, more preferably 10,000 mass ppm or less, further preferably 1,000 mass ppm or less, particularly preferably 100 mass ppm or less.

[0046] In addition, in the case where the composition of the present application is an additive for an electrolyte, the content of compound (1) with respect to the composition (additive) is preferably 80 mass% or more, more preferably 90 mass% or more, further preferably 95 mass% or more, further preferably 99 mass% or more. The upper limit is not particularly limited.

[0047] In the case where the compound (1) is used as a solvent of an electrolyte solution, the content of the compound (1) is preferably 5% by volume or more, more preferably 10% by volume or more, further preferably 20% by volume or more, and particularly preferably 30% by volume or more, with respect to the solvent. In addition, the content of the compound (1) is preferably 80% by volume or less, more preferably 70% by volume or less, further preferably 60% by volume or less, and particularly preferably 50% by volume or less.

[0048] The compound (1) can be synthesized, for example, from a fluorohydrocarbon having an epoxy group and a fluorohydrocarbon having a hydroxyl group. If it is CF2=CF-O-CH2CF=CF2, it can be synthesized by the method of the following Example.

[0049] The composition of the present application preferably contains a compound represented by the following general formula (2) (hereinafter also referred to as compound (2)):

[0050] Rf 3 -O-Rf 4 (2)

[0051] (in the formula, Rf 3 and Rf 4 are the same or different and are an alkyl group having 1 to 10 carbon atoms or a fluoroalkyl group having 1 to 10 carbon atoms; and at least one of Rf 3 and Rf 4 is a fluoroalkyl group.)

[0052] By containing the compound (2), the flame retardancy of the composition is improved, and the stability and safety at high temperature and high voltage are improved. In addition, by using the compound (1) and the compound (2) in combination, a synergistic effect can be exerted, and the effects of improving the cycle characteristics, reducing the electric resistance, and suppressing gas generation can be improved.

[0053] In the general formula (2), at least one of Rf 3 and Rf 4 may be a fluoroalkyl group having 1 to 10 carbon atoms, and from the viewpoint of further improving the flame retardancy and the stability and safety at high temperature and high voltage of the composition, both Rf 3 and Rf 4 are preferably a fluoroalkyl group having 1 to 10 carbon atoms. In this case, Rf 3 and Rf 4 may be the same or different from each other.

[0054] More preferably, one of Rf 3 and Rf 4 is a fluoroalkyl group having 3 to 6 carbon atoms, and the other is a fluoroalkyl group having 2 to 6 carbon atoms.

[0055] Rf3 and Rf 4 may be linear or branched, and is preferably linear.

[0056] Rf 3 and Rf 4 When the total number of carbon atoms of Rf 3 or Rf 4 is too large, the solubility of the electrolyte salt decreases, and the compatibility with other solvents also begins to be adversely affected, in addition to which the viscosity increases, and thus the rate characteristics decrease. From the aspects of the boiling point and the rate characteristics, it is preferable that the number of carbon atoms of one of Rf 3 and Rf 4 be 2 to 3, and the number of carbon atoms of the other be 3 to 4, and it is more preferable that the number of carbon atoms of one be 2, and the number of carbon atoms of the other be 3.

[0057] The boiling point of the compound (2) is preferably 67°C to 120°C. It is more preferable that it be 80°C or higher, and it is further preferable that it be 90°C or higher.

[0058] The fluorine content of the compound (2) is preferably 40 to 75 mass%. When the fluorine content is within this range, the balance between the non-flammability and the compatibility is particularly excellent. Furthermore, it is also preferable from the viewpoint of the good oxidation resistance and safety.

[0059] The lower limit of the above-mentioned fluorine content is more preferably 45 mass%, it is further preferably 50 mass%, and it is particularly preferably 55 mass%. The upper limit is more preferably 70 mass%, it is further preferably 66 mass%.

[0060] In addition, the fluorine content of the compound (2) is a value calculated from the structural formula of the compound (2) by {(number of fluorine atoms x 19) / molecular weight of the compound (2)} x 100 (%).

[0061] As Rf 3 and Rf 4 , for example, CF3CH2-, CF3CFH-, HCF2CH2-, HCF2CFH-, HCF2CF2-, CF3CF2CH2-, CF3CFHCF2-, HCF2CF2CF2-, HCF2CF2CH2-, CF3CF2CH2CH2-, CF3CFHCF2CH2-, HCF2CF2CF2CF2-, HCF2CF2CF2CH2-, HCF2CF2CH2CH2-, HCF2CF(CF3)CH2-, and the like can be given. Among these, it is preferable that one of Rf 3 and Rf 4 be HCF2CF2-, and the other be HCF2CF2CH2-.

[0062] That is, the compound (2) is particularly preferably HCF2CF2-O-CH2CF2CF2H.

[0063] The compound (2) can be used singly or in combination of two or more.

[0064] Further, the compound (2), like the compound (1), can be used as an additive for an electrolyte or a solvent for an electrolyte.

[0065] In the case where the compound (2) is used as an additive for an electrolyte, the content of the compound (2) with respect to the electrolyte is preferably 0.001 mass ppm or more, more preferably 0.1 mass ppm or more, further preferably 0.5 mass ppm or more, particularly preferably 1 mass ppm or more. In addition, the content of the compound (2) is preferably 50,000 mass ppm or less, more preferably 10,000 mass ppm or less, further preferably 1,000 mass ppm or less, particularly preferably 100 mass ppm or less.

[0066] Further, in the case where the composition of the present application is an additive for an electrolyte, the content of the compound (2) with respect to the composition (additive) is preferably 0.0001 mass ppm or more, more preferably 0.002 mass% or more, further preferably 0.01 mass% or more. In addition, the content of the compound (2) is preferably 20 mass% or less, more preferably 10 mass% or less, further preferably 5 mass% or less, further preferably 1 mass% or less.

[0067] Further, in the case where the composition of the present application is an additive for an electrolyte, the total content of the compound (1) and the compound (2) with respect to the composition (additive) is preferably 90 mass% or more, more preferably 95 mass% or more, further preferably 99 mass% or more. There is no particular limitation on the upper limit, and it can be 100 mass%.

[0068] Further, in the case where the composition of the present application is an additive for an electrolyte, the content of the compound (1) is preferably 0.0001 to 100,000 mass ppm of the content of the compound (2). The lower limit is more preferably 0.1 mass ppm, further preferably 0.5 mass ppm, particularly preferably 1 mass ppm. The upper limit is more preferably 50,000 mass ppm, further preferably 500 mass ppm, particularly preferably 100 mass ppm.

[0069] In the case where the compound (2) is used as a solvent for the electrolyte, the content of the compound (2) is preferably 5% by volume or more, more preferably 10% by volume or more, further preferably 20% by volume or more, and particularly preferably 30% by volume or more, relative to the solvent. In addition, the content of the compound (2) is preferably 80% by volume or less, more preferably 70% by volume or less, further preferably 60% by volume or less, and particularly preferably 50% by volume or less.

[0070] In addition, in the case where the compound (2) is used as a solvent for the electrolyte and the compound (1) is used as an additive for the electrolyte, the content of the compound (1) is preferably 0.1 to 85,000 ppm by mass relative to the content of the compound (2). The lower limit is more preferably 0.5 ppm by mass, and further preferably 1 ppm by mass. The upper limit is more preferably 30,000 ppm by mass, further preferably 300 ppm by mass, and particularly preferably 10 ppm by mass.

[0071] The synthesis method of the compound (2) is not particularly limited, and the compound (2) can be synthesized by a general method.

[0072] In the case where the composition of the present application is used as an electrolyte, the composition of the present application preferably contains a solvent (excluding the compound (1) and the compound (2)).

[0073] The above-mentioned solvent preferably contains at least one selected from carbonates and carboxylic acid esters.

[0074] The above-mentioned carbonates can be cyclic carbonates or chain carbonates.

[0075] The above-mentioned cyclic carbonates can be unfluorinated cyclic carbonates or fluorinated cyclic carbonates.

[0076] As the above-mentioned unfluorinated cyclic carbonates, unfluorinated saturated cyclic carbonates can be mentioned, and unfluorinated saturated alkylene carbonates having an alkylene group with 2 to 6 carbon atoms are preferable, and unfluorinated saturated alkylene carbonates having an alkylene group with 2 to 4 carbon atoms are more preferable.

[0077] Among them, as the above-mentioned unfluorinated saturated cyclic carbonates, at least one selected from ethylene carbonate, propylene carbonate, cis-2,3-pentylene carbonate, cis-2,3-butylene carbonate, 2,3-pentylene carbonate, 2,3-butylene carbonate, 1,2-pentylene carbonate, 1,2-butylene carbonate, and butylene carbonate is preferable from the viewpoint of high dielectric constant and suitable viscosity.

[0078] The above-mentioned unfluorinated saturated cyclic carbonates can be used singly or two or more kinds thereof can be used in any combination and at any ratio.

[0079] In the case of containing the above-mentioned non-fluorinated saturated cyclic carbonate, the content of the above-mentioned non-fluorinated saturated cyclic carbonate is preferably 5 to 90% by volume, more preferably 10 to 60% by volume, and further preferably 15 to 45% by volume, relative to the above-mentioned solvent.

[0080] The above-mentioned fluorinated cyclic carbonate is a cyclic carbonate having a fluorine atom. The solvent containing the fluorinated cyclic carbonate can be preferably used even at a high voltage.

[0081] Note that, in the present specification, "high voltage" means a voltage of 4.2 V or more. In addition, the upper limit of "high voltage" is preferably 4.9 V.

[0082] The above-mentioned fluorinated cyclic carbonate can be a fluorinated saturated cyclic carbonate or a fluorinated unsaturated cyclic carbonate.

[0083] The above-mentioned fluorinated saturated cyclic carbonate is a saturated cyclic carbonate having a fluorine atom, and specifically, a compound represented by the following general formula (A) can be mentioned:

[0084] [Chemical Formula 1]

[0085]

[0086] (In the formula, X 1 to X 4 are the same or different and each represent -H, -CH3, -C2H5, -F, a fluorinated alkyl group which can have an ether bond, or a fluorinated alkoxy group which can have an ether bond. Among them, at least one of X 1 to X 4 is -F, a fluorinated alkyl group which can have an ether bond, or a fluorinated alkoxy group which can have an ether bond.) The above-mentioned fluorinated alkyl group means -CF3, -CF2H, -CH2F, etc.

[0087] In the case where the composition of the present application is used as an electrolytic solution, if the composition of the present application contains the above-mentioned fluorinated saturated cyclic carbonate, the oxidation resistance of the electrolytic solution is improved, and stable and excellent charge / discharge characteristics are obtained.

[0088] Note that, in the present specification, "ether bond" is a bond represented by -O-.

[0089] From the viewpoint of dielectric constant and good oxidation resistance, it is preferable that one or two of X 1 to X 4 be -F, a fluorinated alkyl group which can have an ether bond, or a fluorinated alkoxy group which can have an ether bond.

[0090] Since a reduction in viscosity at low temperature, an increase in flash point, and an improvement in solubility of electrolyte salts can be expected, it is preferable that one or two of X 1 to X 4Preferably, it is -H, -F, fluoroalkyl (a), fluoroalkyl with an ether bond (b), or fluoroalkoxy (c).

[0091] The aforementioned fluoroalkyl group (a) is a group obtained by replacing at least one of the hydrogen atoms in an alkyl group with a fluorine atom. The number of carbon atoms in the fluoroalkyl group (a) is preferably 1 to 20, more preferably 1 to 17, even more preferably 1 to 7, and particularly preferably 1 to 5.

[0092] If the number of carbon atoms is too large, the low-temperature performance may decrease or the solubility of the electrolyte salt may decrease. If the number of carbon atoms is too small, the solubility of the electrolyte salt may decrease, the discharge efficiency may decrease, and the viscosity may increase.

[0093] Examples of fluoroalkyl groups (a) with one carbon atom include CFH2-, CF2H-, and CF3-. In particular, CF2H- or CF3- are preferred for high-temperature storage properties, with CF3- being the most preferred.

[0094] Of the fluoroalkyl groups (a) described above, those with two or more carbon atoms are preferably exemplified by the following general formula (a-1) from the viewpoint of good solubility in electrolyte salts:

[0095] R a1 -R a2 -(a-1)

[0096] (where R is in the formula) a1 It is an alkyl group having 1 or more carbon atoms and may contain fluorine atoms; R a2 It is an alkylene group having 1 to 3 carbon atoms and may have fluorine atoms; wherein, R a1 and R a2 At least one of them has a fluorine atom.

[0097] It should be noted that R a1 and R a2 It can also have atoms other than carbon, hydrogen, and fluorine atoms.

[0098] R a1 It can be an alkyl group having one or more carbon atoms and containing fluorine atoms. As R a1 Preferably, it is a straight-chain or branched alkyl group having 1 to 16 carbon atoms. As R a1 The number of carbon atoms is more preferably 1 to 6, and even more preferably 1 to 3.

[0099] As R a1 Specifically, examples of linear or branched alkyl groups include: CH3-, CH3CH2-, CH3CH2CH2-, CH3CH2CH2CH2-, and CH3CH2CH2CH2-.

[0100] [Chemical Formula 2]

[0101]

[0102] and the like.

[0103] In addition, in the case where R a1 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-, and the like.

[0104] In addition, in the case where R a1 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-, and the like.

[0105] [Chemistry 3]

[0106]

[0107] [Chemistry 4]

[0108]

[0109] Among them, if there are branches such as CH3- and CF3-, the viscosity tends to be higher, so it is preferable to have fewer (one) or zero branches.

[0110] R a2 It can be an alkylene group having 1 to 3 carbon atoms and containing fluorine atoms. R a2 It can be linear or branched. An example of such a minimum structural unit constituting a linear or branched alkylene group is shown below. R a2 It consists of them individually or in combination.

[0111] (i) The smallest structural unit in a linear chain:

[0112] -CH2-, -CHF-, -CF2-, -CHCl-, -CFCl-, -CCl2-

[0113] (ii) Branched minimum structural unit:

[0114] [Chemistry 5]

[0115]

[0116] It should be noted that, in the examples above, from the viewpoint of not causing deHCl reaction due to alkali and being more stable, it is preferable to be composed of structural units that do not contain Cl.

[0117] In R a2 In the case of a linear structure, it is composed only of the aforementioned linear minimum structural units, preferably -CH2-, -CH2CH2-, or -CF2-. From the viewpoint of further improving the solubility of the electrolyte salt, -CH2- or -CH2CH2- is more preferred.

[0118] In R a2 In the case of a branched structure, a group comprising at least one of the smallest structural units of the aforementioned branched structure is preferably exemplified by a group of the general formula -(CX). a X b )-(X a For H, F, CH3 or CF3; X b It is CH3 or CF3. Additionally, in X... b In the case of CF3, X aThese are groups represented by H or CH3. These units, in particular, can further improve the solubility of electrolyte salts.

[0119] Preferred fluoroalkyl groups (a) include, for example, CF3CF2-, HCF2CF2-, H2CFCF2-, CH3CF2-, CF3CHF-, CH3CF2-, CF3CF2CF2-, HCF2CF2CF2-, H2CFCF2CF2-, CH3CF2CF2-,

[0120] [Chemistry 6]

[0121]

[0122] [Chemistry 7]

[0123]

[0124] wait.

[0125] The aforementioned fluoroalkyl group (b) with an ether bond is a group obtained by replacing at least one of the hydrogen atoms in an alkyl group with an ether bond with a fluorine atom. The number of carbon atoms in the aforementioned fluoroalkyl group (b) with an ether bond is preferably 2 to 17. If the number of carbon atoms is too high, the viscosity of the aforementioned fluorinated saturated cyclic carbonate increases. Furthermore, due to the increase in fluorine-containing groups, a decrease in the solubility of the electrolyte salt and a decrease in compatibility with other solvents due to a decrease in the dielectric constant are sometimes observed. From this viewpoint, the number of carbon atoms in the aforementioned fluoroalkyl group (b) with an ether bond is more preferably 2 to 10, and even more preferably 2 to 7.

[0126] The alkylene group constituting the ether portion of the fluoroalkyl group (b) having an ether bond described above can be a straight-chain or branched alkylene group. An example of such a minimum structural unit constituting a straight-chain or branched alkylene group is shown below.

[0127] (i) The smallest structural unit in a linear chain:

[0128] -CH2-, -CHF-, -CF2-, -CHCl-, -CFCl-, -CCl2-

[0129] (ii) Branched minimum structural unit:

[0130] [Chemistry 8]

[0131]

[0132] Alkylenes can be composed of these smallest structural units alone, or they can be composed of straight-chain (i) units, branched-chain (ii) units, or a combination of straight-chain (i) and branched-chain (ii) units. Preferred examples are described below.

[0133] It should be noted that in the above examples, from the viewpoint of not causing de-HCl reaction due to alkali, and of being more stable, it is preferable that the structural unit not contain Cl.

[0134] As a further preferred fluoroalkyl group (b) having an ether bond, a group represented by general formula (b-1) can be given:

[0135] R 3 -(OR 4 ) n1 -(b-1)

[0136] (in the formula, R 3 is an alkyl group which can have a fluorine atom, and preferably has 1 to 6 carbon atoms; R 4 is an alkylene group which can have a fluorine atom, and preferably has 1 to 4 carbon atoms; n1 is an integer of 1 to 3; and at least one of R 3 and R 4 has a fluorine atom.)

[0137] As R 3 and R 4 , the following compounds can be given, and they can be appropriately combined to constitute the fluoroalkyl group (b) having an ether bond represented by the above general formula (b-1), but are not limited to these.

[0138] (1) As R 3 , an alkyl group represented by the general formula: X c 3C-(R 5 ) n2 -(3 X c are the same or different, and are each H or F; R 5 is an alkylene group which can have a fluorine atom having 1 to 5 carbon atoms; and n2 is 0 or 1) is preferable.

[0139] In the case where n2 is 0, as R 3 , CH3-, CF3-, HCF2-, and H2CF- can be given.

[0140] As a specific example where n2 is 1, as R 3Examples of linear groups include: CF3CH2-, CF3CF2-, CF3CH2CH2-, CF3CF2CH2-, CF3CF2CF2-, CF3CH2CF2-, CF3CH2CH2CH2-, CF3CF2CH2CH2-, CF3CH2CF2CH2-, CF3CF2CF2CH2-, CF3CF2CF2CF2-, CF3CF2CH2CF2-, CF3CH2CH2CH2CH2-, CF3CF2CH2CH2C H2-, CF3CH2CF2CH2CH2-, CF3CF2CF2CH2CH2-, CF3CF2CF2CF2CH2-, CF3CF2CH2CF2CH2-, CF3CF2CH2CH2CH2CH2-, CF3 CF2CF2CF2CH2CH2-, CF3CF2CH2CF2CH2CH2-, HCF2CH2-, HCF2CF2-, HCF2CH2CH2-, HCF2CF2CH2-, HCF2CH2CF2-, HCF2 CF2CH2CH2-, HCF2CH2CF2CH2-, HCF2CF2CF2CF2-, HCF2CF2CH2CH2CH2-, HCF2CH2CF2CH2CH2-, HCF2CF2CF2CF2CH2-, HCF2CF2CF2CF2CH2CH2-, FCH2CH2-, FCH2CF2-, FCH2CF2CH2-, CH3CF2-, CH3CH2-, CH3CF2CH2-, CH3CF2CF2-, CH3CH2 CH2-, CH3CF2CH2CF2-, CH3CF2CF2CF2-, CH3CH2CF2CF2-, CH3CH2CH2CH2-, CH3CF2CH2CF2CH2-, CH3CF2CF2CF2CH2-, CH3CF2CF2CH2CH2-, CH3CH2CF2CF2CH2-, CH3CF2CH2CF2CH2CH2-, CH3CH2CF2CF2CH2CH2-, CH3CF2CH2CF2CH2CH2-, etc.

[0141] As n2 is 1 and R 3 Examples of branched groups include:

[0142] [Chemistry 9]

[0143]

[0144] wait.

[0145] Among them, if it has branches such as CH3- and CF3-, the viscosity tends to be higher, therefore R is preferred. 3 It is a linear chain.

[0146] (2) the (OR 4 ) n1 - wherein n1 is an integer of 1 to 3, and preferably 1 or 2. In addition, when n1 = 2 or 3, R 4 may be the same or different.

[0147] As a preferred specific example of R 4 , the following straight-chain or branched-chain groups can be exemplified.

[0148] As a straight-chain group, -CH2-, -CHF-, -CF2-, -CH2CH2-, -CF2CH2-, -CF2CF2-, -CH2CF2-, -CH2CH2CH2-, -CH2CH2CF2-, -CH2CF2CH2-, -CH2CF2CF2-, -CF2CH2CH2-, -CF2CF2CH2-, -CF2CH2CF2-, -CF2CF2CF2-, and the like can be exemplified.

[0149] As a branched-chain group, the following can be exemplified:

[0150] [Chemical Formula 10]

[0151]

[0152] and the like.

[0153] The above fluorinated alkoxy group (c) is a group in which at least one of the hydrogen atoms possessed by an alkoxy group is replaced with a fluorine atom. The number of carbon atoms of the above fluorinated alkoxy group (c) is preferably 1 to 17. More preferably, the number of carbon atoms is 1 to 6.

[0154] As the above fluorinated alkoxy group (c), a fluorinated alkoxy group represented by the general formula: X d 3C-(R 6 ) n3 -O-(3 X d are the same or different, and each is H or F; R 6 is preferably an alkylene group which can have a fluorine atom having a number of carbon atoms of 1 to 5; n3 is 0 or 1; and wherein any one of the 3 X d contains a fluorine atom) is particularly preferable.

[0155] As a specific example of the above fluorinated alkoxy group (c), a fluorinated alkoxy group in which an oxygen atom is bonded to the terminal of the alkyl group exemplified as R 1 in the above general formula (a-1) can be exemplified.

[0156] The fluorine content of the fluorinated saturated cyclic carbonate is preferably 10% by mass or more. If the fluorine content is too low, the effects of reducing viscosity at low temperatures and increasing the flash point can not be sufficiently obtained. From this viewpoint, the fluorine content is more preferably 12% by mass or more, and further preferably 15% by mass or more. The upper limit is usually 76% by mass.

[0157] The fluorine content of the fluorinated saturated cyclic carbonate is preferably 10% by mass or more. If the fluorine content is too low, the effects of reducing viscosity at low temperatures and increasing the flash point can not be sufficiently obtained. From this viewpoint, the fluorine content is more preferably 12% by mass or more, and further preferably 15% by mass or more. The upper limit is usually 76% by mass.

[0158] In addition, from the viewpoint of dielectric constant and good 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.

[0159] Note that the fluorine content of the fluorinated saturated cyclic carbonate is a value calculated from the structural formula of the fluorinated saturated cyclic carbonate as {(number of fluorine atoms x 19) / molecular weight of the fluorinated saturated cyclic carbonate} x 100(%).

[0160] As the fluorinated saturated cyclic carbonate, specifically, for example, the following substances can be given.

[0161] As X 1 ~ X 4 The fluorinated saturated cyclic carbonate in which at least one of X

[0162] [Chem. 11]

[0163]

[0164] and the like. These compounds have high withstand voltage and good solubility of electrolyte salts.

[0165] In addition, the following can be used:

[0166] [Chem. 12]

[0167]

[0168] and the like.

[0169] As X 1 ~ X 4 The fluorinated saturated cyclic carbonate in which at least one of X

[0170] [Chem. 13]

[0171]

[0172] [Chem. 14]

[0173]

[0174] [Chem. 15]

[0175]

[0176] and the like.

[0177] as X 1 ~ X 4 Specific examples of the fluoro-saturated cyclic carbonate having an ether bond (b) or fluoroalkoxy group (c) and the rest of which are -H, include the following:

[0178] [Chem. 16]

[0179]

[0180] [Chem. 17]

[0181]

[0182] [Chem. 18]

[0183]

[0184] [Chem. 19]

[0185]

[0186] [Chem. 20]

[0187]

[0188] [Chem. 21]

[0189]

[0190] and the like.

[0191] Among the above fluoro-saturated cyclic carbonates, any one of the following compounds is preferable.

[0192] [Chem. 22]

[0193]

[0194] [Chem. 23]

[0195]

[0196] As the fluorinated saturated cyclic carbonate, in addition to the above-mentioned ones, trans-4,5-difluoro-l,3-dioxolan-2-one, 5-(l,l-difluoroethyl)-4,4-difluoro-l,3-dioxolan-2-one, 4-methylene-l,3-dioxolan-2-one, 4-methyl-5-trifluoromethyl-l,3-dioxolan-2-one, 4-ethyl-5-fluoro-l,3-dioxolan-2-one, 4-ethyl-5,5-difluoro-l,3-dioxolan-2-one, 4-ethyl-4,5-difluoro-l,3-dioxolan-2-one, 4-ethyl-4,5,5-trifluoro-l,3-dioxolan-2-one, 4,4-difluoro-5-methyl-l,3-dioxolan-2-one, 4-fluoro-5-methyl-l,3-dioxolan-2-one, 4-fluoro-5-trifluoromethyl-l,3-dioxolan-2-one, 4,4-difluoro-l,3-dioxolan-2-one, and the like can be mentioned.

[0197] As the fluorinated saturated cyclic carbonate, ethylene carbonate, difluoroethylene carbonate, and trifluoromethyl ethylene carbonate (3,3,3-trifluoro propylene carbonate) are more preferable.

[0198] The above-mentioned 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-phenyl ethylene carbonate, 4,5-difluoro-4-phenyl ethylene carbonate, 4-fluoro-5-phenyl ethylene carbonate, 4-fluoro-5-vinyl ethylene carbonate, 4-fluoro-4-phenyl ethylene carbonate, 4,4-difluoro-4-vinyl ethylene carbonate, 4,4-difluoro-4-allyl ethylene carbonate, 4-fluoro-4-vinyl ethylene carbonate, 4-fluoro-4,5-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 can be mentioned.

[0199] The above-mentioned fluorinated cyclic carbonate can be used alone or in combination of two or more.

[0200] In the case where the above-mentioned fluorinated cyclic carbonate is contained, the content of the above-mentioned fluorinated cyclic carbonate is preferably 5 to 90% by volume, more preferably 10 to 60% by volume, and further preferably 15 to 45% by volume, relative to the above-mentioned solvent.

[0201] The above-mentioned chain carbonate can be an unfluorinated chain carbonate or a fluorinated chain carbonate.

[0202] As the above-mentioned unfluorinated chain carbonate, for example, there are CH3OCOOCH3 (dimethyl carbonate: DMC), CH3CH2OCOOCH2CH3 (diethyl carbonate: DEC), CH3CH2OCOOCH3 (ethyl methyl carbonate: EMC), CH3OCOOCH2CH2CH3 (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, and the like hydrocarbon-based chain carbonates. Of these, at least one selected from the group consisting of ethyl methyl carbonate, diethyl carbonate and dimethyl carbonate is more preferable.

[0203] The above-mentioned unfluorinated chain carbonate can be used singly or two or more kinds thereof can be used in any combination and ratio.

[0204] When the above-mentioned unfluorinated chain carbonate is contained, the content of the above-mentioned unfluorinated chain carbonate with respect to the solvent is preferably 10 to 90% by volume, more preferably 40 to 85% by volume, and further preferably 50 to 80% by volume.

[0205] The above-mentioned fluorinated chain carbonate is a chain carbonate having a fluorine atom. The solvent containing the fluorinated chain carbonate is preferably used even at a high voltage.

[0206] As the above-mentioned fluorinated chain carbonate, there are compounds represented by the general formula (B) :

[0207] Rf a OCOOR 7 (B)

[0208] (In the formula, Rf a 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 can contain a fluorine atom.)

[0209] Rf a 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 can contain a fluorine atom.

[0210] The above-mentioned fluorinated alkyl group is obtained by replacing at least one of the hydrogen atoms of the alkyl group with a fluorine atom. In the case where R 7 is an alkyl group containing a fluorine atom, it becomes a fluorinated alkyl group.

[0211] Rf a and R 7 In terms of low viscosity, the number of carbon atoms is preferably 1 to 7, and more preferably 1 to 2.

[0212] If the number of carbon atoms is too large, sometimes the low-temperature characteristics decrease, or the solubility of the electrolyte salt decreases, and if the number of carbon atoms is too small, sometimes a decrease in the solubility of the electrolyte salt, a decrease in the discharge efficiency, further an increase in the viscosity, and the like are observed.

[0213] As the fluoroalkyl group having 1 carbon atom, CFH2-, CF2H-, CF3-, and the like can be given. In particular, CFH2- or CF3- is preferable in terms of high-temperature storage characteristics.

[0214] As the fluoroalkyl group having 2 or more carbon atoms, from the viewpoint of good solubility of the electrolyte salt, a fluoroalkyl group represented by the following general formula (d-1) can be preferably exemplified:

[0215] R d1 -R d2 -(d-1)

[0216] (In the formula, R d1 is an alkyl group having 1 or more carbon atoms which can have a fluorine atom; R d2 is an alkylene group having 1 to 3 carbon atoms which can have a fluorine atom; and at least one of R d1 and R d2 has a fluorine atom.)

[0217] Note that R d1 and R d2 may also have atoms other than carbon atoms, hydrogen atoms, and fluorine atoms.

[0218] R d1 is an alkyl group having 1 or more carbon atoms which can have a fluorine atom. As R d1 , a linear or branched alkyl group having 1 to 6 carbon atoms is preferable. More preferably, the number of carbon atoms of R d1 is 1 to 3.

[0219] As R d1 , specifically, as the linear or branched alkyl group, CH3-, CF3-, CH3CH2-, CH3CH2CH2-, CH3CH2CH2CH2-,

[0220] [Chem. 24]

[0221]

[0222] and the like.

[0223] In addition, R d1In the case of a straight-chain alkyl group having a fluorine atom, examples that can be given include: 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-, and the like.

[0224] In addition, in the case where R d1 In the case of a branched-chain alkyl group having a fluorine atom, examples that can be given include:

[0225] [Chemical Formula 25]

[0226]

[0227] [Chemical Formula 26]

[0228]

[0229] However, if having a branch such as CH3-, CF3-, the viscosity tends to be high, and thus it is more preferable that the number thereof is small (one) or zero.

[0230] R d2 is an alkylene group having 1 to 3 carbon atoms which can have a fluorine atom. R d2 may be linear or branched. An example of such a minimum structural unit constituting a linear or branched alkylene group is shown below. d2 consisting of them alone or in combination.

[0231] (i) a linear minimum structural unit:

[0232] -CH2-, -CHF-, -CF2-, -CHCI-, -CFCI-, -CCI2-

[0233] (ii) a branched minimum structural unit:

[0234] [Chem. 27]

[0235]

[0236] Note that, among the above examples, from the viewpoint of not causing a de-HCI reaction due to a base and being more stable, it is preferable that the structure is constituted of a structure unit not containing CI.

[0237] R d2 In the case where R is linear, it is constituted of only the above linear minimum structural unit, of which -CH2-, -CH2CH2- or -CF2- is preferable. From the viewpoint of being able to further improve the solubility of the electrolyte salt, -CH2- or -CH2CH2- is more preferable.

[0238] R d2 In the case where R is branched, at least one of the above branched minimum structural units is included, and a group represented by the general formula: -(CX a X b )-(CX a is H, F, CH3or CF3; X b is CH3or CF3(in the case where X b is CF3, X a is H or CH3). These units are particularly capable of further improving the solubility of the electrolyte salt.

[0239] Preferred fluoroalkyl groups include, for example: CF3CF2-, HCF2CF2-, H2CFCF2-, CH3CF2-, CF3CH2-, CF3CF2CF2-, HCF2CF2CF2-, H2CFCF2CF2-, CH3CF2CF2-.

[0240] [Chemistry 28]

[0241]

[0242] [Chemistry 29]

[0243]

[0244] wait.

[0245] Among them, as Rf a and R 7 The fluoroalkyl groups are preferably CF3-, CF3CF2-, (CF3)2CH-, CF3CH2-, C2F5CH2-, CF3CF2CH2-, HCF2CF2CH2-, CF3CFHCF2CH2-, CFH2-, and CF2H-. From the viewpoint of high flame retardancy, good rate characteristics, and good oxidation resistance, CF3CH2-, CF3CF2CH2-, HCF2CF2CH2-, CFH2-, and CF2H- are more preferred.

[0246] R 7 When it is an alkyl group that does not contain fluorine atoms, it is an alkyl group with 1 to 7 carbon atoms. From the viewpoint of low viscosity, R 7 The number of carbon atoms is preferably 1 to 4, and more preferably 1 to 3.

[0247] Examples of alkyl groups that do not contain fluorine atoms include CH3-, CH3CH2-, (CH3)2CH-, and C3H7-. Among these, CH3- and CH3CH2- are preferred due to their low viscosity and good rate characteristics.

[0248] Preferably, the fluorine content of the above-mentioned fluorinated chain carbonate is 15% to 70% by mass. If the fluorine content is within the above range, it is possible to maintain compatibility with solvents and solubility in salts. More preferably, the fluorine content is 20% by mass or more, further preferably 30% by mass or more, particularly preferably 35% by mass or more, more preferably 60% by mass or less, and even more preferably 50% by mass or less.

[0249] It should be noted that, in this invention, the fluorine content is a value calculated based on the structural formula of the above-mentioned fluorinated chain carbonate:

[0250] {(Number of fluorine atoms × 19) / Molecular weight of fluorinated chain carbonate} × 100 (%)

[0251] As the above-mentioned fluorinated chain carbonate, in terms of low viscosity, any one of the following compounds is preferable.

[0252] [Chemical Formula 30]

[0253]

[0254] As the above-mentioned fluorinated chain carbonate, methyl 2,2,2-trifluoroethyl carbonate (F3CH2COC(=O)OCH3) is particularly preferable.

[0255] The above-mentioned fluorinated chain carbonate can be used alone or two or more kinds thereof can be used in any combination and ratio.

[0256] When the above-mentioned fluorinated chain carbonate is contained, the content of the fluorinated chain carbonate with respect to the solvent is preferably 10 to 90% by volume, more preferably 40 to 85% by volume, and further preferably 50 to 80% by volume.

[0257] The above-mentioned carboxylic acid ester can be a cyclic carboxylic acid ester or a chain carboxylic acid ester.

[0258] The above-mentioned cyclic carboxylic acid ester can be an unfluorinated cyclic carboxylic acid ester or a fluorinated cyclic carboxylic acid ester.

[0259] As the above-mentioned unfluorinated cyclic carboxylic acid ester, an unfluorinated saturated cyclic carboxylic acid ester having an alkylene group with 2 to 4 carbon atoms is preferable.

[0260] Specific examples of the unfluorinated saturated cyclic carboxylic acid ester having an alkylene group with 2 to 4 carbon atoms include β-propiolactone, γ-butyrolactone, ε-caprolactone, δ-valerolactone, and α-methyl-γ-butyrolactone. Among them, γ-butyrolactone and δ-valerolactone are particularly preferable from the viewpoint of improving the lithium ion dissociation degree and improving the load characteristics.

[0261] The above-mentioned unfluorinated saturated cyclic carboxylic acid ester can be used alone or two or more kinds thereof can be used in any combination and ratio.

[0262] When the above-mentioned unfluorinated saturated cyclic carboxylic acid ester is contained, the content of the unfluorinated saturated cyclic carboxylic acid ester with respect to the solvent is preferably 0 to 90% by volume, more preferably 0.001 to 90% by volume, further preferably 1 to 60% by volume, and particularly preferably 5 to 40% by volume.

[0263] The above-mentioned chain carboxylic acid ester can be an unfluorinated chain carboxylic acid ester or a fluorinated chain carboxylic acid ester. In the case where the above-mentioned solvent contains the above-mentioned chain carboxylic acid ester, the increase in the resistance of the electrolyte solution after high-temperature storage can be further suppressed.

[0264] As the non-fluorinated chain carboxylic acid ester, for example, there can be mentioned 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, 2-propynylethyl oxalate, isopropyl formate, isopropyl butyrate, isobutyl formate, isobutyl propionate, isobutyl butyrate, isobutyl acetate, and the like.

[0265] Among them, butyl acetate, methyl propionate, ethyl propionate, propyl propionate, butyl propionate are preferable, and ethyl propionate, propyl propionate are particularly preferable.

[0266] The above non-fluorinated chain carboxylic acid ester can be used singly or two or more kinds thereof can be used in any combination and at any ratio.

[0267] When the non-fluorinated chain carboxylic acid ester is contained, the content of the non-fluorinated chain carboxylic acid ester is preferably 0 to 90% by volume, more preferably 0.001 to 90% by volume, further preferably 1 to 60% by volume, and particularly preferably 5 to 40% by volume, relative to the solvent.

[0268] The above fluorinated chain carboxylic acid ester is a chain carboxylic acid ester having a fluorine atom. The solvent containing the fluorinated chain carboxylic acid ester is preferably used even at a high voltage.

[0269] As the above fluorinated chain carboxylic acid ester, from the viewpoints of good compatibility with other solvents and good oxidation resistance, a fluorinated chain carboxylic acid ester represented by the following general formula is preferable:

[0270] R 31 COOR 32

[0271] (In the formula, R 31 and R 32 are each independently an alkyl group which can have a fluorine atom having 1 to 4 carbon atoms, and at least one of R 31 and R 32 contains a fluorine atom.)

[0272] R 31 and R 32, for example, non-fluorinated alkyl groups such as methyl (-CH3), ethyl (-CH2CH3), propyl (-CH2CH2CH3), isopropyl (-CH(CH3)2), n-butyl (-CH2CH2CH2CH3), t-butyl (-C(CH3)3), and the like; -CF3, -CF2H, -CFH2, -CF2CF3, -CF2CF2H, -CF2CFH2, -CH2CF3, -CH2CF2H, -CH2CFH2, -CF2CF2CF3, -CF2CF2CF2H, -CF2CF2CFH2, -CH2CF2CF3, -CH2CF2CF2H, -CH2CF2CFH2, -CH2CH2CF3, -CH2CH2CF2H, -CH2CH2CFH2, -CF(CF3)2, -CF(CF2H)2, -CF(CFH2)2, -CH(CF3)2, -CH(CF2H)2, -CH(CFH2)2, -CF(OCH3)CF3, -CF2CF2CF2CF3, -CF2CF2CF2CF2H, -CF2CF2CF2CFH2, -CH2CF2CF2CF3, -CH2CF2CF2CF2H, -CH2CF2CF2CFH2, -CH2CH2CF2CF3, -CH2CH2CF2CF2H, -CH2CH2CF2CFH2, -CH2CH2CH2CF3, -CH2CH2CH2CF2H, -CH2CH2CH2CFH2, -CF(CF3)CF2CF3, -CF(CF2H)CF2CF3, -CF(CFH2)CF2CF3, -CF(CF3)CF2CF2H, -CF(CF3)CF2CFH2, -CF(CF3)CH2CF3, -CF(CF3)CH2CF2H, -CF(CF3)CH2CFH2, -CH(CF3)CF2CF3, -CH(CF2H)CF2CF3, -CH(CFH2)CF2CF3, -CH(CF3)CF2CF2H, -CH(CF3)CF2CFH2, -CH(CF3)CH2CF3, -CH(CF3)CH2CF2H, -CH(CF3)CH2CFH2, -CF2CF(CF3)CF3, -CF2CF(CF2H)CF3, -CF2CF(CFH2)CF3, -CF2CF(CF3)CF2H, -CF2CF(CF3)CFH2, -CH2CF(CF3)CF3, -CH2CF(CF2H)CF3, -CH2CF(CFH2)CF3, -CH2CF(CF3)CF2H, -CH2CF(CF3)CFH2, -CH2CH(CF3)CF3, -CH2CH(CF2H)CF3, -CH2CH(CFH2)CF3, -CH2CH(CF3)CF2H,-CH2CH(CF3)CFH2, -CF2CH(CF3)CF3, -CF2CH(CF2H)CF3, -CF2CH(CFH2)CF3, -CF2CH(CF3)CF2H, -CF2CH(CF3)CFH2, -C(CF3)3, -C(CF2H)3, -C(CFH2)3, and the like fluorinated alkyl groups. Among them, from the viewpoint of compatibility with other solvents, viscosity, and good oxidation resistance, methyl, ethyl, -CF3, -CF2H, -CF2CF3, -CH2CF3, -CH2CF2H, -CH2CFH2, -CH2CH2CF3, -CH2CF2CF3, -CH2CF2CF2H, -CH2CF2CFH2 are particularly preferable.

[0273] As specific examples of the above-mentioned fluorinated chain carboxylic acid ester, for example, one or two or more of CF3CH2C(=O)OCH3 (methyl 3,3,3-trifluoropropionate), HCF2C(=O)OCH3 (methyl difluoroacetate), HCF2C(=O)OC2H5 (ethyl difluoroacetate), CF3C(=O)OCH2C2CF3, CF3C(=O)OCH2CF2CF5, CF3C(=O)OCH2CF2CF2H (2,2,3,3-tetrafluoropropyl trifluoroacetate), CF3C(=O)OCH2CF3, CF3C(=O)OCH(CF3)2, ethyl pentafluorobutyrate, methyl pentafluoropropionate, ethyl pentafluoropropionate, methyl heptafluoroisobutyrate, 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, CH3C(=O)OCH2CF3 (2,2,2-trifluoroethyl acetate), 1H, 1H-heptafluorobutyl acetate, methyl 4,4,4-trifluorobutyrate, ethyl 4,4,4-trifluorobutyrate, ethyl 3,3,3-trifluoropropionate, 3,3,3-trifluoropropyl 3,3,3-trifluoropropionate, ethyl 3-(trifluoromethyl)butyrate, methyl 2,3,3,3-tetrafluoropropionate, butyl 2,2-difluoroacetate, methyl 2,2,3,3-tetrafluoropropionate, methyl 2-(trifluoromethyl)-3,3,3-trifluoropropionate, methyl heptafluorobutyrate, and the like can be exemplified.

[0274] CF3CH2C(=O)OCH3, HCF2C(=O)OCH3, HCF2C(=O)OC2H5, CF3C(=O)OCH2C2F5, CF3C(=O)OCH2CF2CF2H, CF3C(=O)OCH2CF3, CF3C(=O)OCH(CF3)2, ethyl pentafluorobutyrate, methyl pentafluoropropionate, ethyl pentafluoropropionate, methyl heptafluoroisobutyrate, 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, CH3C(=O)OCH2CF3, 1H, 1H-heptafluorobutyl acetate, methyl 4,4,4-trifluorobutyrate, ethyl 4,4,4-trifluorobutyrate, ethyl 3,3,3-trifluoropropionate, 3,3,3-trifluoropropyl 3,3,3-trifluoropropionate, ethyl 3-(trifluoromethyl)butyrate, methyl 2,3,3,3-tetrafluoropropionate, butyl 2,2-difluoroacetate, methyl 2,2,3,3-tetrafluoropropionate, methyl 2-(trifluoromethyl)-3,3,3-trifluoropropionate, methyl heptafluorobutyrate, more preferably CF3CH2C(=O)OCH3, HCF2C(=O)OCH3, HCF2C(=O)OC2H5, CH3C(=O)OCH2CF3, and particularly preferably HCF2C(=O)OCH3, HCF2C(=O)OC2H5, CH3C(=O)OCH2CF3.

[0275] The above-mentioned fluorinated chain carboxylic acid ester can be used alone or in combination of two or more kinds in any ratio.

[0276] When the fluorinated chain carboxylic acid ester is contained, the content of the fluorinated chain carboxylic acid ester is preferably 10 to 90 vol%, more preferably 40 to 85 vol%, and further preferably 50 to 80 vol% with respect to the solvent.

[0277] The above-mentioned solvent preferably contains at least one selected from the above-mentioned cyclic carbonate, the above-mentioned chain carbonate, and the above-mentioned chain carboxylic acid ester, and more preferably contains the above-mentioned cyclic carbonate and at least one selected from the above-mentioned chain carbonate and the above-mentioned chain carboxylic acid ester. The above-mentioned cyclic carbonate is preferably a saturated cyclic carbonate.

[0278] The electrolyte containing the above-mentioned solvent composition can further improve the high-temperature storage characteristics and cycle characteristics of the electrochemical device.

[0279] When the solvent comprises the cyclic carbonate and at least one selected from the chain carbonate and the chain carboxylic acid ester, the cyclic carbonate and at least one selected from the chain carbonate and the chain carboxylic acid ester are preferably contained in a total of 10 to 90% by volume, more preferably 30 to 80% by volume, further preferably 50 to 70% by volume.

[0280] When the solvent comprises the cyclic carbonate and at least one selected from the chain carbonate and the chain carboxylic acid ester, the volume ratio of the cyclic carbonate and at least one selected from the chain carbonate and the chain carboxylic acid ester is preferably 5 / 95 to 95 / 5; more preferably 10 / 90 or more, further preferably 15 / 85 or more, particularly preferably 20 / 80 or more; more preferably 90 / 10 or less, further preferably 60 / 40 or less, particularly preferably 50 / 50 or less.

[0281] The above solvent preferably further comprises at least one selected from the above non-fluorinated saturated cyclic carbonate, the above non-fluorinated chain carbonate and the above non-fluorinated chain carboxylic acid ester, more preferably comprises the above non-fluorinated saturated cyclic carbonate and at least one selected from the above non-fluorinated chain carbonate and the above non-fluorinated chain carboxylic acid ester. An electrolyte containing the above solvent is suitably used for an electrochemical device used at a lower voltage.

[0282] When the above solvent comprises the above non-fluorinated saturated cyclic carbonate and at least one selected from the above non-fluorinated chain carbonate and the above non-fluorinated chain carboxylic acid ester, the above non-fluorinated saturated cyclic carbonate and at least one selected from the above non-fluorinated chain carbonate and the above non-fluorinated chain carboxylic acid ester are preferably contained in a total of 5 to 90% by volume, more preferably 20 to 80% by volume, further preferably 30 to 70% by volume.

[0283] When the electrolyte contains the above non-fluorinated saturated cyclic carbonate and at least one selected from the above non-fluorinated chain carbonate and the above non-fluorinated chain carboxylic acid ester, the volume ratio of the above non-fluorinated saturated cyclic carbonate and at least one selected from the above non-fluorinated chain carbonate and the above non-fluorinated chain carboxylic acid ester is preferably 5 / 95 to 95 / 5; more preferably 10 / 90 or more, further preferably 15 / 85 or more, particularly preferably 20 / 80 or more; more preferably 90 / 10 or less, further preferably 60 / 40 or less, particularly preferably 50 / 50 or less.

[0284] The above solvent preferably further contains at least one selected from the above fluorinated saturated cyclic carbonate, the above fluorinated chain carbonate, and the above fluorinated chain carboxylic acid ester, more preferably contains the above fluorinated saturated cyclic carbonate and at least one selected from the above fluorinated chain carbonate and the above fluorinated chain carboxylic acid ester. The electrolyte containing the solvent of the above composition is not only suitable for use in electrochemical devices using at a lower voltage, but also suitable for use in electrochemical devices using at a higher voltage.

[0285] When the solvent contains the fluorinated saturated cyclic carbonate and at least one selected from the fluorinated chain carbonate and the fluorinated chain carboxylic acid ester, the fluorinated saturated cyclic carbonate and at least one selected from the fluorinated chain carbonate and the fluorinated chain carboxylic acid ester are preferably contained at 5 to 100% by volume in total, more preferably at 10 to 100% by volume, further preferably at 30 to 100% by volume.

[0286] When the solvent contains the fluorinated saturated cyclic carbonate and at least one selected from the fluorinated chain carbonate and the fluorinated chain carboxylic acid ester, the volume ratio of the fluorinated saturated cyclic carbonate and at least one selected from the fluorinated chain carbonate and the fluorinated chain carboxylic acid ester is preferably 5 / 95 to 95 / 5; more preferably 10 / 90 or more, further preferably 15 / 85 or more, particularly preferably 20 / 80 or more; more preferably 90 / 10 or less, further preferably 60 / 40 or less, particularly preferably 50 / 50 or less.

[0287] In addition, as the above solvent, an ionic liquid (in which a compound (1) is excluded) can also be used. The "ionic liquid" refers to a liquid composed of ions of organic cations and anions.

[0288] As the organic cation, there is no particular limitation, and for example, imidazolium ions such as dialkylimidazolium cations and trialkylimidazolium cations; tetraalkylammonium ions; alkylpyridinium ions; dialkylpyrrolidinium ions; and dialkylpiperidinium ions can be given.

[0289] As the anion that counterbalances these organic cations, there is no particular limitation, and for example, PF6 anions, PF3(C2F5)3 anions, PF3(CF3)3 anions, BF4 anions, BF2(CF3)2 anions, BF3(CF3) anions, bisoxalato borate anions, P(C2O4)F2 anions, Tf (trifluoromethylsulfonyl) anions, Nf (nonafluorobutylsulfonyl) anions, bis(fluorosulfonyl)imide anions, bis(trifluoromethylsulfonyl)imide anions, bis(pentafluoroethylsulfonyl)imide anions, dicyanamide anions, halide anions can be used.

[0290] The above solvent is preferably a nonaqueous solvent, and the composition of the present application is preferably a nonaqueous electrolyte solution.

[0291] The content of the solvent in the electrolyte solution is preferably 70 to 99.999 mass%, more preferably 80 mass% or more, and more preferably 92 mass% or less.

[0292] The composition of the present application can further contain a compound (3) represented by General Formula (3).

[0293] General Formula (3):

[0294] [Chemical Formula 31]

[0295]

[0296] (In the formula, A a+ is a metal ion, hydrogen or a onium ion, a is an integer of 1 to 3, b is an integer of 1 to 3, p is b / a, n203 is an integer of 1 to 4, n201 is an integer of 0 to 8, n202 is 0 or 1, Z 201 is a transition metal, an element of Group III, Group IV or Group V of the periodic table.

[0297] X 201 is 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 (the alkylene group, the halogenated alkylene group, the arylene group and the halogenated arylene group can have a substituent, a hetero atom in its structure, and in addition, when n202 is 1 and n203 is 2 to 4, n203 X 201 may be respectively bonded).

[0298] L 201 is 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 can have a substituent, a hetero atom in its structure, and in addition, when n201 is 2 to 8, n201 L 201 may be respectively bonded to form a ring) or -Z 203 Y 203 .

[0299] Y 201 , Y 202 and Z 203 are each independently O, S, NY 204 , a hydrocarbon group or a fluorinated hydrocarbon group. Y 203 and Y 204each independently 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 halogenated aryl group having 6 to 20 carbon atoms (the alkyl group, the halogenated alkyl group, the aryl group, and the halogenated aryl group can have a substituent, a hetero atom in its structure, and Y 203 or Y 204 In the case where a plurality of them are present, they can be bonded respectively to form a ring.

[0300] 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, lanthanoid ion, actinoid ion, tetrabutylammonium ion, tetraethylammonium ion, tetramethylammonium ion, triethylmethylammonium ion, triethylammonium ion, pyridinium ion, imidazolium ion, hydrogen ion, tetraethylphosphonium ion, tetramethylphosphonium ion, tetraphenylphosphonium ion, triphenylsulfonium ion, triethylsulfonium ion, and the like.

[0301] In the case of use for an electrochemical device or the like, A a+ is preferably lithium ion, sodium ion, magnesium ion, tetraalkylammonium ion, hydrogen ion, and particularly preferably lithium ion. a+ The valence number a of the cation of A is an integer of 1 to 3. In the case of more than 3, the lattice energy becomes large, and thus a problem of difficulty in solubility in a solvent is caused. Therefore, in the case where solubility is required, 1 is more preferable. The valence number b of the anion is also an integer of 1 to 3, and particularly preferably 1. The constant p representing the ratio of the cation to the anion is necessarily determined by the ratio of the valence numbers b / a of both.

[0302] Next, a part of the ligand of General Formula (3) is described. In the present specification, the part of General Formula (3) that binds to Z 201 is referred to as a ligand.

[0303] 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, and more preferably Al, B, or P.

[0304] X 201represents O, 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 and arylene groups can have a substituent, a hetero atom in their structures. Specifically, instead of hydrogen on the alkylene and arylene groups, 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 group, an acyl group, an amido group, a hydroxyl group, or a structure in which nitrogen, sulfur, or oxygen is introduced instead of carbon on the alkylene and arylene groups can be a substituent. In addition, when n202is 1 and n203is 2 to 4, the n203X 201 may be bonded respectively. As such examples, a ligand such as ethylenediaminetetraacetic acid can be given.

[0305] 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, or -Z 203 Y 203 (about Z 203 , Y 203 will be described later). The alkyl group and aryl group here also have the same meaning as X 201 Similarly, a substituent, a hetero atom can be present in their structures, and in addition, when n201is 2 to 8, the n201L 201 may be bonded respectively to form a ring. As L 201 , a fluorine atom or a cyano group is preferable. This is because, in the case of a fluorine atom, the solubility and dissociation degree of the salt of the anion compound are improved, and the ion conductivity is improved. In addition, the oxidation resistance is also improved, and thus the occurrence of side reactions can be suppressed.

[0306] Y 201 , Y 202 , and Z 203 each independently represent O, S, NY 204 , a hydrocarbon group, or a fluorinated hydrocarbon group. Y 201 , and Y 202 are preferably O, S, or NY 204 , and more preferably O. As a feature of the compound (3), Y 201 , and Y 202 are bonded to Z 201 , and thus these ligands and Z 201 form a chelate structure. By the effect of this chelation, the heat resistance, chemical stability, and hydrolysis resistance of the compound are improved. The constant n202in this ligand is 0 or 1, but particularly, in the case where n202is 0, since the chelate ring is a five-membered ring, the chelation effect is most strongly exerted, and the stability is increased, and thus is preferable.

[0307] Note that in the present specification, a fluoroalkyl group is a group in which at least one of the hydrogen atoms in an alkyl group is replaced with a fluorine atom.

[0308] Y 203 and Y 204 each independently H, F, an alkyl group having 1 to 10 carbon atoms, a haloalkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms, or a haloaryl group having 6 to 20 carbon atoms, the alkyl group and aryl group can have a substituent or a hetero atom in its structure, and in addition, Y 203 or Y 204 In the case where a plurality of them are present, they can be bonded respectively to form a ring.

[0309] In addition, the constant n203 related to the number of the above-mentioned ligand is an integer of 1 to 4, preferably 1 or 2, and more preferably 2. In addition, the constant n201 related to the number of the above-mentioned ligand 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 n201 be 2 when n203 is 1, and n201 be 0 when n203 is 2.

[0310] In General Formula (3), the alkyl group, haloalkyl group, aryl group, and haloaryl group also include groups having a branched chain or a hydroxyl group, an ether bond, and other functional groups.

[0311] Compound (3) is a compound represented by General Formula:

[0312] [Chemical Formula 32]

[0313]

[0314] (In the formula, A a+ , a, b, p, n201, Z 201 , and L 201 as described above), or a compound represented by General Formula:

[0315] [Chemical Formula 33]

[0316]

[0317] (In the formula, A a+ , a, b, p, n201, Z 201 , and L 201 as described above).

[0318] As Compound (3), lithium oxalato borate salts can be given, and lithium bisoxalato borate (LIBOB) represented by the following formula can be given.

[0319] [Chemical Formula 34]

[0320]

[0321] Lithium difluorooxalato borate (LIDFOB) represented by the following formula:

[0322] [Chemical Formula 35]

[0323]

[0324] Lithium difluorooxalato phosphate (LIDFOP) represented by the following formula:

[0325] [Chemical Formula 36]

[0326]

[0327] Lithium tetrafluorooxalato phosphate (LITFOP) represented by the following formula:

[0328] [Chemical Formula 37]

[0329]

[0330] Lithium difluorobisoxalato phosphate represented by the following formula:

[0331] [Chemical Formula 38]

[0332]

[0333] and the like.

[0334] As the compound (3), lithium bis (malonato) borate, lithium difluoro (malonato) borate, lithium bis (methylmalonato) borate, lithium difluoro (methylmalonato) borate, lithium bis (dimethylmalonato) borate, lithium difluoro (dimethylmalonato) borate and the like, which are dicarboxylic acid complex salts having boron as the complex center element, can also be mentioned.

[0335] As the compound (3), lithium tris (oxalato) phosphate, lithium tris (malonato) phosphate, lithium difluorobis (malonato) phosphate, lithium tetrafluoro (malonato) phosphate, lithium tris (methylmalonato) phosphate, lithium difluorobis (methylmalonato) phosphate, lithium tetrafluoro (methylmalonato) phosphate, lithium tris (dimethylmalonato) phosphate, lithium difluorobis (dimethylmalonato) phosphate, lithium tetrafluoro (dimethylmalonato) phosphate and the like, which are dicarboxylic acid complex salts having phosphorus as the complex center element, can also be mentioned.

[0336] As the compound (3), lithium aluminum (C2O4) 2, lithium aluminum fluoride (C2O4) and the like, which are dicarboxylic acid complex salts having aluminum as the complex center element, can also be mentioned.

[0337] Among them, from the viewpoint of easy availability and contribution to formation of a stable film-like structure, more preferably, lithium bis(oxalato)borate, lithium difluoro(oxalato)borate, lithium tris(oxalato)phosphate, lithium difluorobis(oxalato)phosphate, lithium tetrafluorobis(oxalato)phosphate are used.

[0338] As the compound (3), lithium bis(oxalato)borate is particularly preferable.

[0339] From the viewpoint of obtaining further superior cycle characteristics, as the content of the compound (3), relative to the above-mentioned solvent, preferably, 0.001 mass% or more, more preferably, 0.01 mass% or more; preferably, 10 mass% or less, more preferably, 3 mass% or less.

[0340] In the case where the composition of the present application is used as an electrolyte solution, the composition of the present application preferably further contains an electrolyte salt (in which, in addition to the compound (3)). As the above-mentioned electrolyte salt, any substance which can be used in an electrolyte solution, such as a liquid salt (ionic liquid) other than a lithium salt, an ammonium salt, a metal salt, an inorganic high molecular type salt, an organic high molecular type salt, etc. can be used.

[0341] As the electrolyte salt of the electrolyte solution for lithium ion secondary batteries, a lithium salt is preferable.

[0342] As the above-mentioned lithium salt, any lithium salt can be used, and specifically, the following lithium salts can be mentioned. For example, LiPF6, LiBF4, LiClO4, LiAlF4, LiSbF6, LiTaF6, LiWF7, LiAsF6, LiAlCl4, LiI, LiBr, LiCl, LiB 10 Cl 10 Li2SiF6, Li2PFO3, LiPO2F2, etc. inorganic lithium salts;

[0343] LiWOF5, etc. lithium tungstate;

[0344] HCO2Li, CH3CO2Li, CH2FCO2Li, CHF2CO2Li, CF3CO2Li, CF3CH2CO2Li, CF3CF2CO2Li, CF3CF2CF2CO2Li, CF3CF2CF2CF2CO2Li, etc. lithium carboxylate salts;

[0345] FSO3Li, CH3SO3Li, CH2FSO3Li, CHF2SO3Li, CF3SO3Li, CF3CF2SO3Li, CF3CF2CF2SO3Li, CF3CF2CF2CF2SO3Li, lithium methylsulfate, lithium ethylsulfate (C2H5OSO3Li), lithium 2,2,2-trifluoroethylsulfate, etc. lithium salts having a S=O group;

[0346] LiN(FCO)2, LiN(FCO)(FSO2), LiN(FSO2)2, LiN(FSO2)(CF3SO2), LiN(CF3SO2)2, LiN(C2F5SO2)2, lithium bisperfluoroethanesulfonylimide, lithium cyclic 1,2-perfluoroethane disulfonylimide, lithium cyclic 1,3-perfluoropropane disulfonylimide, lithium cyclic 1,2-ethane disulfonylimide, lithium cyclic 1,3-propane disulfonylimide, lithium cyclic 1,4-perfluorobutane disulfonylimide, LiN(CF3SO2)(FSO2), LiN(CF3SO2)(C3F7SO2), LiN(CF3SO2)(C4F9SO2), LiN(POF2)2, and the like lithium imide salts;

[0347] LiC(FSO2)3, LiC(CF3SO2)3, LiC(C2F5SO2)3, and the like methyl lithium salts;

[0348] In addition, salts represented by the formula: LiPF a (C n F 2n+1 ) 6-a (wherein a is an integer of 0 to 5, and n is an integer of 1 to 6) (for example, 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, and the like fluorine-containing organic lithium salts, LiSCN, LiB(CN)4, LiB(C6H5)4, Li2(C2O4), LiP(C2O4)3, Li2B 12 F b H 12-b (b is an integer of 0 to 3), and the like.

[0349] Among them, from the viewpoint of the effects of improvement in output characteristics, high-rate charge / discharge characteristics, high-temperature storage characteristics, cycle characteristics, and the like, LiPF6, LiBF4, LiSbF6, LiTaF6, LiPO2F2, FSO3Li, CF3SO3Li, LiN(FSO2)2, LiN(FSO2)(CF3SO2), LiN(CF3SO2)2, LiN(C2F5SO2)2, cyclic 1,2-perfluoroethane disulfonimide lithium, cyclic 1,3-perfluoropropane disulfonimide lithium, LiC(FSO2)3, LiC(CF3SO2)3, LiC(C2F5SO2)3, LiBF3CF3, LiBF3C2F5, LiPF3(CF3)3, LiPF3(C2F5)3, and the like are particularly preferable, and at least one lithium salt selected from the group consisting of LiPF6, LiN(FSO2)2, and LiBF4is most preferable.

[0350] These electrolyte salts can be used alone or in combination of two or more. A preferable example of the combination of two or more is the combination of LiPF6and LiBF4, or the combination of LiPF6, LiPO2F2, C2H5OSO3Li, or FSO3Li, which has the effect of improving high-temperature storage characteristics, load characteristics, and cycle characteristics.

[0351] In this case, the blending amount of LiBF4, LiPO2F2, C2H5OSO3Li, or FSO3Li relative to 100 mass% of the entire electrolyte solution is not limited, and is an arbitrary blending amount as long as the effect of the present application is not significantly impaired, but is usually 0.01 mass% or more, preferably 0.1 mass% or more, and is usually 30 mass% or less, preferably 20 mass% or less, more preferably 10 mass% or less, and further preferably 5 mass% or less, relative to the electrolyte solution.

[0352] Further, another example is the combination use of an inorganic lithium salt and an organic lithium salt, and the combination use of these two has the effect of suppressing deterioration due to high-temperature storage. As the organic lithium salt, CF3SO3Li, LiN(FSO2)2, LiN(FSO2)(CF3SO2), LiN(CF3SO2)2, LiN(C2F5SO2)2, cyclic 1,2-perfluoroethane disulfonimide lithium, cyclic 1,3-perfluoropropane disulfonimide lithium, LiC(FSO2)3, LiC(CF3SO2)3, LiC(C2F5SO2)3, LiBF3CF3, LiBF3C2F5, LiPF3(CF3)3, LiPF3(C2F5)3, and the like are preferable. In this case, the proportion of the organic lithium salt relative to 100 mass% of the entire electrolyte solution is preferably 0.1 mass% or more, particularly preferably 0.5 mass% or more, and is preferably 30 mass% or less, particularly preferably 20 mass% or less.

[0353] The concentration of these electrolyte salts in the electrolyte solution is not particularly limited as long as the effects of the present application are not impaired. From the viewpoint of keeping the conductivity of the electrolyte solution within a good range and ensuring good battery performance, the total molar concentration of lithium in the electrolyte solution is preferably 0.3 mol / L or greater, more preferably 0.4 mol / L or greater, and further preferably 0.5 mol / L or greater, and is preferably 3 mol / L or less, more preferably 2.5 mol / L or less, and further preferably 2.0 mol / L or less.

[0354] If the total molar concentration of lithium is too low, the conductivity of the electrolyte solution is sometimes insufficient, whereas if the concentration is too high, the conductivity is sometimes reduced due to an increase in viscosity, and battery performance is sometimes reduced.

[0355] As the electrolyte salt of the electrolyte solution for electric double layer capacitors, an ammonium salt is preferable.

[0356] As the ammonium salt, the following (IIa) to (IIe) can be given.

[0357] (IIa) Tetraalkyl quaternary ammonium salt

[0358] A tetraalkyl quaternary ammonium salt represented by General Formula (IIa) can be preferably given as an example:

[0359] [Chemical Formula 39]

[0360]

[0361] (In the formula, R 1a , R 2a , R 3a , and R 4a are the same or different and can each be an alkyl group that can include an ether bond having 1 to 6 carbon atoms; X - is an anion).

[0362] Furthermore, from the viewpoint of improving oxidation resistance, an ammonium salt in which some or all of the hydrogen atoms are substituted with fluorine atoms and / or fluorine-containing alkyl groups having 1 to 4 carbon atoms is preferable.

[0363] As a specific example, a tetraalkyl quaternary ammonium salt represented by General Formula (IIa-1) can be given:

[0364] [Chemical Formula 40]

[0365]

[0366] (In the formula, R 1a , R 2a , and X - are the same as described above; x and y are the same or different and are integers of 0 to 4, and x + y = 4),

[0367] alkyl ether group-containing trialkylammonium salt represented by General Formula (IIa-2):

[0368] [Chemical Formula 41]

[0369]

[0370] (In the formula, 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; and X - is an anion.)

[0371] and the like. By introducing an alkyl ether group, the viscosity can be reduced.

[0372] Anion X - may be an inorganic anion or an organic anion. As the inorganic anion, for example, A1C14 - , BF4 - , PF6 - , AsF6 - , TaF6 - , I - , SbF6 - may be given. As the organic anion, for example, bisoxalato borate anion, difluoro oxalato borate anion, tetrafluoro oxalato phosphate anion, difluoro bisoxalato phosphate anion, CF3COO - , CF3SO3 - , (CF3SO2)2N - , (C2F5SO2)2N - , and the like can be given.

[0373] Among them, from the viewpoint of oxidation resistance and good ion dissociation, BF4 - , PF6 - , AsF6 - , SbF6 - are preferable.

[0374] As preferable specific examples of the quaternary ammonium salt of tetraalkyl, there can be mentioned Et4NBF4, Et4NClO4, Et4NPF6, Et4NAsF6, Et4NSbF6, Et4NCF3SO3, Et4N(CF3SO2)2N, Et4NC4F9SO3, Et3MeNBF4, Et3MeNClO4, Et3MeNPF6, Et3MeNAsF6, Et3MeNSbF6, Et3MeNCF3SO3, Et3MeN(CF3SO2)2N, Et3MeNC4F9SO3, and in particular, Et4NBF4, Et4NPF6, Et4NSbF6, Et4NAsF6, Et3MeNBF4, N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium salt, and the like.

[0375] (IIb) spiro-bispyrrolidinium salt

[0376] A spiro-bispyrrolidinium salt represented by general formula (IIb-1) is preferably mentioned:

[0377] [Chemical Formula 42]

[0378]

[0379] (In the formula, 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; n1 is an integer of 0 to 5; and n2 is an integer of 0 to 5),

[0380] A spiro-bispyrrolidinium salt represented by general formula (IIb-2):

[0381] [Chemical Formula 43]

[0382]

[0383] (In the formula, R 10a and R 11a are the same or different and each is an alkyl group having 1 to 4 carbon atoms; X - is an anion; n3 is an integer of 0 to 5; and n4 is an integer of 0 to 5), or

[0384] A spiro-bispyrrolidinium salt represented by general formula (IIb-3):

[0385] [Chemical Formula 44]

[0386]

[0387] (In the formula, 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; n5 is an integer of 0 to 5; and n6 is an integer of 0 to 5.

[0388] Further, a substance in which some or all of the hydrogen atoms of the spirobispyridazinium salt are substituted with fluorine atoms and / or fluorine-containing alkyl groups having 1 to 4 carbon atoms is also preferable from the viewpoint of improving oxidation resistance.

[0389] Anion X - Preferred specific examples are the same as in the case of (IIa). Among them, from the viewpoint of high dissociation and low internal resistance at high voltage, BF4", PF6", (CF3SO2)2N", or (C2F5SO2)2N" is preferable.

[0390] As preferred specific examples of the spirobispyridazinium salt, for example, the following can be given:

[0391] [Chemical Formula 45]

[0392]

[0393] and the like.

[0394] The spirobispyridazinium salt is excellent in solubility in solvents, oxidation resistance, and ionic conductivity.

[0395] (IId) Pyrazolium salt

[0396] As the pyrazolium salt, a pyrazolium salt represented by General Formula (IId) is preferable:

[0397] [Chemical Formula 46]

[0398]

[0399] (In the formula, R 14a and R 15a are the same or different and each is an alkyl group having 1 to 6 carbon atoms; and X - is an anion).

[0400] Further, a substance in which some or all of the hydrogen atoms of the pyrazolium salt are substituted with fluorine atoms and / or fluorine-containing alkyl groups having 1 to 4 carbon atoms is also preferable from the viewpoint of improving oxidation resistance.

[0401] Anion X - Preferred specific examples are the same as in the case of (IIa).

[0402] As preferred specific examples, for example, the following can be given:

[0403] [Chemical Formula 47]

[0404]

[0405] and the like.

[0406] The N-alkylpyridinium salt is excellent in low viscosity and further good solubility.

[0407] (IId) : N-alkylpyridinium salt

[0408] The N-alkylpyridinium salt represented by the general formula (IId) can be preferably exemplified:

[0409] [Chemical Formula 48]

[0410]

[0411] (In the formula, R 16a is an alkyl group having 1 to 6 carbon atoms; X - is an anion).

[0412] Further, a substance in which some or all of the hydrogen atoms of the N-alkylpyridinium salt are replaced with fluorine atoms and / or fluorine-containing alkyl groups having 1 to 4 carbon atoms is also preferable from the viewpoint of improving oxidation resistance.

[0413] The anion X - is the same as that of (IIa).

[0414] As preferable specific examples, for example, the following can be given:

[0415] [Chemical Formula 49]

[0416]

[0417] and the like.

[0418] The N-alkylpyridinium salt is excellent in low viscosity and further good solubility.

[0419] (IIe) N,N-dialkylpyrrolidinium salt

[0420] The N,N-dialkylpyrrolidinium salt represented by the general formula (IIe) can be preferably exemplified:

[0421] [Chemical Formula 50]

[0422]

[0423] (In the formula, 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).

[0424] Further, a substance in which some or all of the hydrogen atoms of the N,N-dialkylpyrrolidinium salt are replaced with fluorine atoms and / or fluorine-containing alkyl groups having 1 to 4 carbon atoms is also preferable from the viewpoint of improving oxidation resistance.

[0425] Anion X - Preferred specific examples are the same as (IIa).

[0426] As preferred specific examples, for example, the following can be mentioned:

[0427] [Chemical Formula 51]

[0428]

[0429] [Chemical Formula 52]

[0430]

[0431] and the like.

[0432] This N,N-dialkylpyrrolidinium salt is excellent in terms of low viscosity and further good solubility.

[0433] Among these ammonium salts, (IIa), (IIb), and (IIc) are preferred in terms of solubility, oxidation resistance, and ion conductivity, and further preferred are:

[0434] [Chemical Formula 53]

[0435]

[0436] (In the formula, Me is a methyl group; Et is an ethyl group; X - , x, y, and formula (IIa-1) are the same).

[0437] In addition, as the electrolyte salt for a double-layer capacitor, a lithium salt can be used. As the lithium salt, for example, LiPF6, LiBF4, LiN(FSO2)2, LiAsF6, LiSbF6, LiN(SO2C2H5)2are preferred.

[0438] In order to further increase the capacity, a magnesium salt can be used. As the magnesium salt, for example, Mg(ClO4)2, Mg(OOC2H5)2, and the like are preferred.

[0439] In the case where the electrolyte salt is the above-described ammonium salt, the concentration is preferably 0.7 mol / liter or more. If it is less than 0.7 mol / liter, it is possible that not only the low-temperature characteristics deteriorate, but also the initial internal resistance becomes high. The concentration of the above-described electrolyte salt is more preferably 0.9 mol / liter or more.

[0440] The upper limit of the above-described concentration is preferably 2.0 mol / liter or less, and more preferably 1.5 mol / liter or less, in terms of low-temperature characteristics.

[0441] In the case where the above-mentioned ammonium salt is triethylmethylammonium tetrafluoroborate (TEMABF4), its concentration is preferably 0.7 to 1.5 mol / liter from the viewpoint of excellent low-temperature characteristics.

[0442] Further, in the case of spirobipyrrolidinium tetrafluoroborate (SBPBF4), the concentration is preferably 0.7 to 2.0 mol / liter.

[0443] The composition of the present application preferably further contains a compound (4) represented by General Formula (4):

[0444] [Formula 54]

[0445]

[0446] (In the formula, X 21 is a group containing at least H or C, n21 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, n22 is 0 or 1, Y 21 and Z 21 may be bonded to each other to form a ring.) If the above-mentioned electrolyte solution contains the compound (4), the capacity retention rate is less likely to further decrease and the amount of gas generation is less likely to further increase even in the case of storage at high temperature.

[0447] In the case where n21 is 2 or 3, 2 or 3 X 21 may be the same or different.

[0448] In the case where a plurality of Y 21 and Z 21 are present, the plurality of Y 21 and Z 21 may be the same or different.

[0449] As X 21 , -CY 21 Z 21 (In the formula, Y 21 and Z 21 are the same as described above) or -CY 21 =CZ 21 (In the formula, Y 21 and Z 21 are the same as described above) is preferable.

[0450] As Y 21 , at least one selected from the group consisting of H-, F-, CH3-, CH3CH2-, CH3CH2CH2-, CF3-, CF3CF2-, CH2FCH2- and CF3CF2CF2- is preferable.

[0451] As Z21 , preferably at least one selected from the group consisting of H-, F-, CH3-, CH3CH2-, CH3CH2CH2-, CF3-, CF3CF2-, CH2FCH2-, and CF3CF2CF2-.

[0452] or Y 21 and Z 21 may be bonded to each other to include an unsaturated bond, and can form a carbocyclic ring or a heterocyclic ring which can have aromaticity. The number of carbon atoms of the ring is preferably 3 to 20.

[0453] Next, specific examples of the compound (4) will be described. Note that in the following examples, "analog" means an acid anhydride obtained by replacing a part of the structure of the exemplified acid anhydride with another structure within a range not deviating from the gist of the present application, for example, a dimer, a trimer, a tetramer, or the like composed of a plurality of acid anhydrides, or a structural isomer having the same number of carbon atoms of a substituent but having a branched chain, or a substance in which a substituent is bonded to a different position of an acid anhydride.

[0454] As specific examples of the acid anhydride forming a five-membered ring structure, there can be mentioned succinic anhydride, methylsuccinic anhydride (4-methylsuccinic anhydride), dimethylsuccinic anhydride (4,4-dimethylsuccinic 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-diphenylmaleic anhydride, itaconic anhydride, 5-methylitaconic anhydride, 5,5-dimethylitaconic anhydride, phthalic anhydride, 3,4,5,6-tetrahydrophthalic anhydride, etc., and analogs thereof, etc.

[0455] As specific examples of the acid anhydride forming a six-membered ring structure, there can be mentioned cyclohexane dicarboxylic anhydride (cyclohexane-1,2-dicarboxylic anhydride, etc.), 4-cyclohexene-1,2-dicarboxylic anhydride, glutaric anhydride, glutaconic anhydride, 2-phenylglutaric anhydride, etc., and analogs thereof, etc.

[0456] As specific examples of the acid anhydride forming other ring structures, there can be mentioned 5-norbornene-2,3-dicarboxylic anhydride, cyclopentane tetracarboxylic dianhydride, pyromellitic anhydride, diglycolic anhydride, etc., and analogs thereof, etc.

[0457] As specific examples of the acid anhydride which forms a ring structure and is substituted with a halogen atom, monofluorosuccinic anhydride (4-fluorosuccinic anhydride, etc.), 4,4-difluorosuccinic anhydride, 4,5-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, and analogs thereof, etc. can be given.

[0458] As the compound (2), pentane dicarboxylic anhydride, citraconic anhydride, pentene dicarboxylic anhydride, itaconic anhydride, diglycolic anhydride, cyclohexane dicarboxylic anhydride, cyclopentane tetracarboxylic dianhydride, 4-cyclohexene-1,2-dicarboxylic anhydride, 3,4,5,6-tetrahydrophthalic anhydride, 5-norbornene-2,3-dicarboxylic anhydride, phenylsuccinic anhydride, 2-phenylpentane dicarboxylic anhydride, maleic anhydride, methylmaleic anhydride, trifluoromethylmaleic anhydride, phenylmaleic anhydride, succinic anhydride, methylsuccinic anhydride, dimethylsuccinic anhydride, trifluoromethylsuccinic anhydride, monofluorosuccinic anhydride, tetrafluorosuccinic anhydride, etc. are preferable, maleic anhydride, methylmaleic anhydride, trifluoromethylmaleic anhydride, succinic anhydride, methylsuccinic anhydride, trifluoromethylsuccinic anhydride, tetrafluorosuccinic anhydride are more preferable, and maleic anhydride, succinic anhydride are further preferable.

[0459] The compound (4) is preferably a compound (5) represented by General Formula (5):

[0460] [Chemical Formula 55]

[0461]

[0462] (In the formula, X 31 ~X 34 are the same or different and at least include H, C, O, or F.), and a compound (6) represented by General Formula (6):

[0463] [Chemical Formula 56]

[0464]

[0465] (In the formula, X 41 and X 42 are the same or different and at least include H, C, O, or F.)

[0466] are at least one of the above.

[0467] As X 31 ~X 34 , the same or different, at least one selected from the group consisting of an alkyl group, a fluoroalkyl group, an alkenyl group, and a fluoroalkenyl group is preferable. The number of carbon atoms of X 31 ~X 34 is preferably 1 to 10, more preferably 1 to 3.

[0468] X is 31 X is 34 the same or different, more preferably at least one selected from the group consisting of H-, F-, CH3-, CH3CH2-, CH3CH2CH2-, CF3-, CF3CF2-, CH2FCH2-, and CF3CF2CF2-.

[0469] X is 41 X is 42 the same or different, preferably at least one selected from the group consisting of alkyl, fluoroalkyl, alkenyl, and fluoroalkenyl. 41 the number of carbon atoms of X 42 is preferably 1 to 10, more preferably 1 to 3.

[0470] X is 41 X is 42 the same or different, more preferably at least one selected from the group consisting of H-, F-, CH3-, CH3CH2-, CH3CH2CH2-, CF3-, CF3CF2-, CH2FCH2-, and CF3CF2CF2-.

[0471] The compound (5) is preferably any one of the following compounds.

[0472] [Chem. 57]

[0473]

[0474] The compound (6) is preferably any one of the following compounds.

[0475] [Chem. 58]

[0476]

[0477] From the viewpoint that the storage capacity retention rate is not easily further decreased and the gas generation amount is not easily further increased even at high temperatures, it is preferable that the electrolyte solution contain 0.0001 to 15% by mass of the compound (4) with respect to the electrolyte solution. As the content of the compound (4), it is more preferable that it be 0.01 to 10% by mass, further preferable that it be 0.1 to 3% by mass, and particularly preferable that it be 0.1 to 1.0% by mass.

[0478] In the case where the electrolyte contains both of the compounds (3) and (4), from the viewpoint that the storage capacity retention rate is not easily further decreased even at high temperature and the gas generation amount is not easily further increased, the electrolyte preferably contains 0.08 to 2.50 mass% of the compound (3) and 0.02 to 1.50 mass% of the compound (4), more preferably contains 0.80 to 2.50 mass% of the compound (3) and 0.08 to 1.50 mass% of the compound (4).

[0479] In the case where the composition of the present application is used as an electrolyte, the composition of the present application can contain at least one nitrile compound selected from the group consisting of compounds represented by the following general formulae (la), (lb) and (lc).

[0480] [Chemical Formula 59]

[0481]

[0482] (In the formula, R a and R b each independently represent a hydrogen atom, a cyano group (CN), a halogen atom, an alkyl group, or a group in which at least a part of the hydrogen atoms of the alkyl group is replaced with a halogen atom. n represents an integer of 1 to 10)

[0483] [Chemical Formula 60]

[0484]

[0485] (In the formula, R c represents a hydrogen atom, a halogen atom, an alkyl group, a group in which at least a part of the hydrogen atoms of the alkyl group is replaced with a halogen atom, or a group represented by NC-R c1 -X c1 -(R c1 represents an alkylene group, X c1 represents 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 a group in which at least a part of the hydrogen atoms of the alkyl group is replaced with a halogen atom. m represents an integer of 1 to 10)

[0486] [Chemical Formula 61]

[0487] (In the formula, R f , R g , R h and R i each independently represent a group containing a cyano group (CN), a hydrogen atom (H), a halogen atom, an alkyl group, or a group in which at least a part of the hydrogen atoms of the alkyl group is replaced with a halogen atom. Furthermore, R f , R g , R hat least one of R i l represents an integer of 1 to 3

[0488] Thus, the high-temperature storage properties of the electrochemical device can be improved. The above nitrile compound can be used alone, or two or more kinds thereof can be used in any combination and at any ratio.

[0489] In the above general formula (1a), R a and R b each independently is a hydrogen atom, a cyano group (CN), a halogen atom, an alkyl group, or a group in which at least one hydrogen atom of the alkyl group is replaced with a halogen atom.

[0490] As the halogen atom, for example, a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom can be given. Among them, a fluorine atom is preferred.

[0491] As the alkyl group, an alkyl group having 1 to 5 carbon atoms is preferred. As specific examples of the alkyl group, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tert-butyl group, and the like can be given.

[0492] As the group in which at least one hydrogen atom of the alkyl group is replaced with a halogen atom, a group in which at least one hydrogen atom of the above alkyl group is replaced with the above halogen atom can be given.

[0493] In the case where R a and R b is an alkyl group or a group in which at least one hydrogen atom of the alkyl group is replaced with a halogen atom, R a and R b may be bonded to each other to form a ring structure (for example, a cyclohexane ring).

[0494] R a and R b is preferably a hydrogen atom or an alkyl group.

[0495] In the above general formula (1a), n represents an integer of 1 to 10. In the case where n is 2 or more, n R a may be the same or at least a part of them can be 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.

[0496] As the nitrile compound represented by the above general formula (1a), a dinitrile and a trinitrile are preferred.

[0497] As specific examples of the dinitrile, propylene dinitrile, butylene dinitrile, pentylene dinitrile, hexylene dinitrile, heptylene dinitrile, octylene dinitrile, nonylene dinitrile, decylene dinitrile, undecylene dinitrile, dodecylene dinitrile, methylpropylene dinitrile, ethylpropylene dinitrile, isopropylpropylene dinitrile, tert-butylpropylene dinitrile, methylbutylene dinitrile, 2,2-dimethylbutylene dinitrile, 2,3-dimethylbutylene dinitrile, 2,3,3-trimethylbutylene dinitrile, 2,2,3,3-tetramethylbutylene dinitrile, 2,3-diethyl-2,3-dimethylbutylene dinitrile, 2,2-diethyl-3,3-dimethylbutylene dinitrile, bicyclohexane-1,1-dimethylene dinitrile, bicyclohexane-2,2-dimethylene dinitrile, bicyclohexane-3,3-dimethylene dinitrile, 2,5-dimethyl-2,5-hexane dinitrile, 2,3-diisobutyl-2,3-dimethylbutylene dinitrile, 2,2-diisobutyl-3,3-dimethylbutylene dinitrile, 2-methylpentylene dinitrile, 2,3-dimethylpentylene dinitrile, 2,4-dimethylpentylene dinitrile, 2,2,3,3-tetramethylpentylene dinitrile, 2,2,4,4-tetramethylpentylene dinitrile, 2,2,3,4-tetramethylpentylene dinitrile, 2,3,3,4-tetramethylpentylene dinitrile, 1,4-dicyanopentane, 2,6-dicyanoheptane, 2,7-dicyano-octane, 2,8-dicyano-nonane, 1,6-dicyano-decane, 1,2-dicyanobenzene, 1,3-dicyanobenzene, 1,4-dicyanobenzene, 3,3'-(ethylenedioxy)dipropionitrile, 3,3'-(ethylenedithio)dipropionitrile, 3,9-bis(2-cyanoethyl)-2,4,8,10-tetraoxaspiro[5,5]undecane, butyronitrile, phthalonitrile, and the like can be exemplified. Among these, butylene dinitrile, pentylene dinitrile, and hexylene dinitrile are particularly preferable.

[0498] Further, as specific examples of the trinitrile, pentaerythritol tri-nitrile, trimethylolpropane tri-nitrile, 1,3,5-hexanetriol tri-nitrile, 1,3,6-hexanetriol tri-nitrile, heptylene tri-nitrile, 1,2,3-propanetriol tri-nitrile, 1,3,5-pentanetriol tri-nitrile, cyclohexane tri-nitrile, tricyanoethylamine, tricyanoethoxylpropane, tricyanoethylene, tris(2-cyanoethyl)amine, and the like can be exemplified, 1,3,6-hexanetriol tri-nitrile and cyclohexane tri-nitrile are particularly preferable, and cyclohexane tri-nitrile is most preferable.

[0499] In the above general formula (1b), R c represents a hydrogen atom, a halogen atom, an alkyl group, a group in which at least a part of the hydrogen atoms of the alkyl group is replaced with a halogen atom, or NC-R c1 -X c1 -(R c1 represents an alkylene group, X c1 represents an oxygen atom or a sulfur atom) represents a group, R d and R e each independently represents a hydrogen atom, a halogen atom, an alkyl group, or a group in which at least a part of the hydrogen atoms of the alkyl group is replaced with a halogen atom.

[0500] For groups in which at least a portion of the hydrogen atoms of a halogen atom, alkyl group, and alkyl group are replaced by halogen atoms, examples of groups exemplified with respect to the above general formula (1a) can be given.

[0501] The above NC-R c1 -X c1 -in R c1 It is an alkylene group. Preferably, it is an alkylene group having 1 to 3 carbon atoms.

[0502] R c R d and R e Each is preferably a group in which at least a portion of the hydrogen atoms of a hydrogen atom, a halogen atom, an alkyl group, or an alkyl group in which at least a portion of the hydrogen atoms are replaced by halogen atoms.

[0503] R c R d and R e At least one of them is preferably a halogen atom or a group in which at least a portion of the hydrogen atoms of an alkyl group are replaced by halogen atoms, more preferably a fluorine atom or a group in which at least a portion of the hydrogen atoms of an alkyl group are replaced by fluorine atoms.

[0504] In R d and R e In the case of an alkyl group or a group in which at least some of the hydrogen atoms of an alkyl group are replaced by halogen atoms, R d and R e They can bond with each other to form a ring structure (e.g., a cyclohexane ring).

[0505] In the above general formula (1b), m is an integer from 1 to 10. When m is 2 or more, there are m R... d They can be completely identical, or at least partially different. This also applies to R. e m is preferably an integer from 2 to 7, and more preferably an integer from 2 to 5.

[0506] Examples of nitrile compounds represented by the above general formula (1b) include acetonitrile, propionitrile, butyronitrile, isobutyronitrile, valeronitrile, isovaleronitrile, lauronitrile, 3-methoxypropionitrile, 2-methylbutyronitrile, trimethylacetonitrile, hexanonitrile, cyclopentaneformitrile, cyclohexaneformitrile, 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'-oxodipropionitrile, 3,3'-thiodipropionitrile, pentafluoropropionitrile, methoxyacetonitrile, and benzonitrile. Among these, 3,3,3-trifluoropropionitrile is particularly preferred.

[0507] In the above general formula (1c), R f R g R h and Ri each independently a group containing a cyano group (CN), a hydrogen atom, a halogen atom, an alkyl group, or a group in which at least a part of hydrogen atoms of the alkyl group is replaced with a halogen atom.

[0508] As the halogen atom, the alkyl group, and the group in which at least a part of hydrogen atoms of the alkyl group is replaced with a halogen atom, the groups exemplified for the above general formula (1a) can be mentioned.

[0509] As the group containing a cyano group, a group in which at least a part of hydrogen atoms of the alkyl group is replaced with a cyano group can be mentioned in addition to the cyano group. As the alkyl group in this case, the groups exemplified for the above general formula (1a) can be mentioned.

[0510] R f , R g , R h , and R i 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 h , R i is a group containing a cyano group. In the case where R h , and R i is a group containing a cyano group, R f , and R g are preferably hydrogen atoms.

[0511] In the above general formula (1c), 1 is an integer of 1 to 3. In the case where 1 is 2 or more, the 1 R f may be all the same or at least a part of them can be different. The same applies to R g . 1 is preferably an integer of 1 to 2.

[0512] As the nitrile compound represented by the above general formula (1c), 3-hexenedinitrile, hexadienedinitrile, maleonitrile, fumaronitrile, propenenitrile, methacrylonitrile, butenenitrile, 3-methylbutenenitrile, 2-methyl-2-butenenitrile, 2-pentenenitrile, 2-methyl-2-pentenenitrile, 3-methyl-2-pentenenitrile, 2-hexenenitrile, and the like can be mentioned, and 3-hexenedinitrile, hexadienedinitrile are preferred, and 3-hexenedinitrile is particularly preferred.

[0513] The content of the above nitrile compound with respect to the electrolytic solution is preferably 0.2 to 7% by mass. Thereby, the high-temperature storage characteristics at high voltage and the safety of the electrochemical device can be further improved. The lower limit of the total of the contents of the above nitrile compound is more preferably 0.3% by mass, and further preferably 0.5% by mass. The upper limit is more preferably 5% by mass, and further preferably 2% by mass, and particularly preferably 0.5% by mass.

[0514] In the case where the composition of the present application is used as an electrolytic solution, the composition of the present application can contain a compound having an isocyanate group (hereinafter sometimes referred to simply as "isocyanate"). As the above-mentioned isocyanate, there is no particular limitation, and any isocyanate can be used. As examples of the isocyanate, monoisocyanates, diisocyanates, triisocyanates, and the like can be given.

[0515] As specific examples of the monoisocyanates, isocyanomethane, isocyanethane, 1-isocyanopropane, 1-isocyanobutane, 1-isocyanopentane, 1-isocyanohexane, 1-isocyanoheptane, 1-isocyanooctane, 1-isocyanononane, 1-isocyanodecane, isocyanocyclohexane, methoxycarbonylisocyanate, ethoxycarbonylisocyanate, propoxycarbonylisocyanate, butoxycarbonylisocyanate, methoxysulfonylisocyanate, ethoxysulfonylisocyanate, propoxysulfonylisocyanate, butoxysulfonylisocyanate, fluorosulfonylisocyanate, methyl isocyanate, butyl isocyanate, phenyl isocyanate, 2-isocyanatoethyl acrylate, 2-isocyanatoethyl methacrylate, ethyl isocyanate, and the like can be given.

[0516] As specific examples of the diisocyanate, 1,4-diisocyanatobutane, 1,5-diisocyanatopentane, 1,6-diisocyanatohexane, 1,7-diisocyanatohexane, 1,8-diisocyanatooctane, 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, toluene diisocyanate, xylene diisocyanate, toluene 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, 2,5-bis(isocyanatomethyl)bicyclo[2.2.1]heptane, 2,6-bis(isocyanatomethyl)bicyclo[2.2.1]heptane, 2,4,4-trimethylhexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, hexamethylene diisocyanate, 1,4-phenylene diisocyanate, octamethylene diisocyanate, tetramethylene diisocyanate, and the like can be given.

[0517] As specific examples of the triisocyanate, 1,6,11-triisocyanatoundecane, 4-isocyanatomethyl-1,8-octamethylene diisocyanate, 1,3,5-triisocyanatomethylbenzene, 1,3,5-tris(6-isocyanatohexan-1-yl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 4-(isocyanatomethyl)octamethylene diisocyanate, and the like can be given.

[0518] Among them, 1,6-diisocyanatohexane, 1,3-bis(isocyanatomethyl)cyclohexane, 1,3,5-tris(6-isocyanatohexan-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 easily available, and the manufacturing cost of the electrolytic solution can be suppressed low, and thus are preferable, and in addition, from a technical viewpoint, it is also possible to contribute to the formation of a stable film-shaped structure, and more preferably used.

[0519] The content of the isocyanate is not particularly limited, and is an arbitrary content as long as the effect of the present application is not significantly impaired, but is preferably 0.001 mass% or more and 1.0 mass% or less with respect to the electrolytic solution. If the content of the isocyanate is above the lower limit, the effect of sufficiently improving the cycle characteristics can be brought to the nonaqueous electrolyte secondary battery. In addition, if it is below the upper limit, the initial increase in resistance of the nonaqueous electrolyte secondary battery can be avoided. The content of the isocyanate is more preferably 0.01 mass% or more, further preferably 0.1 mass% or more, and particularly preferably 0.2 mass% or more, and is more preferably 0.8 mass% or less, further preferably 0.7 mass% or less, and particularly preferably 0.6 mass% or less.

[0520] In the case where the composition of the present application is used as an electrolytic solution, the composition of the present application can contain a cyclic sulfonic acid ester. As the cyclic sulfonic acid ester, an arbitrary cyclic sulfonic acid ester can be used without particular limitation. As examples of the cyclic sulfonic acid ester, saturated cyclic sulfonic acid esters, unsaturated cyclic sulfonic acid esters, saturated cyclic disulfonic acid esters, unsaturated cyclic disulfonic acid esters, and the like can be given.

[0521] As specific examples of the saturated cyclic sulfonic acid ester, 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-propane sultone, 2-methyl-1,3-propane sultone, 3-methyl-1,3-propane sultone, 1,3-butane sultone, 1,4-butane sultone, 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, and the like can be given.

[0522] As specific examples of the unsaturated cyclic sulfonic acid ester, 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-1,4-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-sultone, 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-1,4-sultone, and the like can be given.

[0523] 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 are more preferable in terms of easy availability and contribution to formation of a stable film-shaped structure. The content of the cyclic sulfonic acid ester is not particularly limited, and is an arbitrary content as long as the effect of the present application is not significantly impaired, but is preferably 0.001 mass% or more and 3.0 mass% or less with respect to the electrolytic solution.

[0524] If the content of the cyclic sulfonic acid ester is above the lower limit, sufficient effects of improving the cycle characteristics of the nonaqueous electrolyte secondary battery can be obtained. In addition, if it is below the upper limit, an increase in the manufacturing cost of the nonaqueous electrolyte secondary battery can be avoided. The content of the cyclic sulfonic acid ester is more preferably 0.01% by mass or more, further preferably 0.1% by mass or more, and particularly preferably 0.2% by mass or more, and more preferably 2.5% by mass or less, further preferably 2.0% by mass or less, and particularly preferably 1.8% by mass or less.

[0525] In the case where the composition of the present application is used as an electrolyte, the composition of the present application can further contain a polyethylene oxide having a weight average molecular weight of 2000 to 4000 and having -OH, -OCOOH or -COOH at the terminal.

[0526] By containing such a compound, the stability of the electrode interface is improved, and the characteristics of the electrochemical device can be improved.

[0527] As the above polyethylene oxide, for example, polyethylene oxide monool, polyethylene oxide formic acid, polyethylene oxide diol, polyethylene oxide diformic acid, polyethylene oxide triol, polyethylene oxide triformic acid, etc. can be given. They can be used alone or in combination of two or more.

[0528] Among them, in terms of further improving the characteristics of the electrochemical device, a mixture of polyethylene oxide monool and polyethylene oxide diol, and a mixture of polyethylene formic acid and polyethylene diformic acid are preferred.

[0529] If the weight average molecular weight of the above polyethylene oxide is too small, it can be easily oxidized and decomposed. The weight average molecular weight is more preferably 3000 to 4000.

[0530] The above weight average molecular weight can be measured by polystyrene conversion using a gel permeation chromatography (GPC) method.

[0531] The content of the above polyethylene oxide is preferably 1 x 10 -6 mol / kg to 1 x 10 -2 mol / kg in the electrolyte. If the content of the above polyethylene oxide is too much, the characteristics of the electrochemical device can be impaired.

[0532] The content of the above polyethylene oxide is more preferably 5 x 10 -6 mol / kg or more.

[0533] In the case where the composition of the present application is used as an electrolyte, the composition of the present application can further contain a fluorinated saturated cyclic carbonate, an unsaturated cyclic carbonate, an overcharge-preventing agent, other publicly known additives, etc. as an additive. Thereby, the decrease in the characteristics of the electrochemical device can be suppressed.

[0534] Examples of fluorinated saturated cyclic carbonates include compounds represented by the above general formula (A). Among these, fluoroethylene carbonate, difluoroethylene carbonate, monofluoromethyl ethylene carbonate, trifluoromethyl ethylene carbonate, and 2,2,3,3,3-pentafluoropropyl ethylene carbonate (4-(2,2,3,3,3-pentafluoropropyl)-[1,3]dioxapentane-2-one) are preferred. A single fluorinated saturated cyclic carbonate can be used alone, or two or more can be used in any combination and ratio.

[0535] The content of the fluorinated saturated cyclic carbonate relative to the electrolyte is preferably 0.001 to 10% by mass, more preferably 0.01 to 5% by mass, and even more preferably 0.1 to 3% by mass.

[0536] Examples of unsaturated cyclic carbonates include vinylene carbonates, ethylene carbonates substituted with substituents having aromatic rings or carbon-carbon double or triple bonds, phenyl carbonates, ethylene carbonates, allyl carbonates, and catechol carbonates.

[0537] Examples of vinylene carbonates include vinylene carbonate, methyl vinylene carbonate, 4,5-dimethyl vinylene carbonate, phenyl vinylene carbonate, 4,5-diphenyl vinylene carbonate, vinyl vinylene carbonate, 4,5-divinyl vinylene carbonate, allyl vinylene carbonate, 4,5-diallyl vinylene carbonate, 4-fluorovinylene carbonate, 4-fluoro-5-methyl vinylene carbonate, 4-fluoro-5-phenyl vinylene carbonate, 4-fluoro-5-vinyl vinylene carbonate, 4-allyl-5-fluorovinylene carbonate, ethynyl ethylene carbonate, propynyl ethylene carbonate, methyl vinylene carbonate, and dimethyl vinylene carbonate.

[0538] Specific examples of ethylene carbonates substituted with substituents having aromatic rings or carbon-carbon double or triple bonds 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-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-diallyl ethylene carbonate, 4-methyl-5-allyl ethylene carbonate, 4-methylene-1,3-dioxolane-2-one, 4,5-dioxolane-1,3-dioxolane-2-one, 4-methyl-5-allyl ethylene carbonate, etc.

[0539] Among them, as the unsaturated cyclic carbonate, vinylene carbonate, methyl vinylene carbonate, 4,5-dimethyl vinylene carbonate, vinyl vinylene carbonate, 4,5-vinyl vinylene carbonate, allyl vinylene carbonate, 4,5-diallyl vinylene 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 ethylene carbonate are preferable. In addition, vinylene carbonate, vinyl ethylene carbonate, ethynyl ethylene carbonate form a more stable interface protective coating film, and thus are particularly preferable, with vinylene carbonate being most preferable.

[0540] The molecular weight of the unsaturated cyclic carbonate is not particularly limited, and is an arbitrary molecular weight as long as the effect of the present application is not significantly impaired. The molecular weight is preferably 50 or greater and 250 or less. If within this range, the solubility of the unsaturated cyclic carbonate with respect to the electrolyte solution is easily ensured, and the effect of the present application is easily sufficiently exerted. The molecular weight of the unsaturated cyclic carbonate is more preferably 80 or greater, and further more preferably 150 or less.

[0541] The method of producing the unsaturated cyclic carbonate is not particularly limited, and an arbitrary known method can be used for production.

[0542] The unsaturated cyclic carbonate can be used alone or in combination of two or more in an arbitrary combination and ratio.

[0543] The content of the above unsaturated cyclic carbonate is not particularly limited, and is an arbitrary content as long as the effect of the present application is not significantly impaired. The content of the unsaturated cyclic carbonate is preferably 0.001% by mass or greater, more preferably 0.01% by mass or greater, and further more preferably 0.1% by mass or greater, in 100% by mass of the electrolyte solution. Furthermore, the above content is preferably 5% by mass or less, more preferably 4% by mass or less, and further more preferably 3% by mass or less. If within the above range, the electrochemical device using the electrolyte solution easily exhibits a sufficient cycle characteristic improvement effect, and furthermore, a decrease in high-temperature storage characteristics, an increase in gas generation amount, and a decrease in discharge capacity maintenance rate are easily avoided.

[0544] As the unsaturated cyclic carbonate, in addition to the above non-fluorinated unsaturated cyclic carbonate, a fluorinated unsaturated cyclic carbonate can also be appropriately used.

[0545] The fluorinated unsaturated cyclic carbonate is a cyclic carbonate having an unsaturated bond with a fluorine atom. There is no particular limitation as long as the fluorinated unsaturated cyclic carbonate has one or more fluorine atoms. Among them, the number of fluorine atoms is usually six or less, preferably four or less, and most preferably one or two.

[0546] As the fluorinated unsaturated cyclic carbonate, a fluorinated vinylene carbonate derivative, a fluorinated ethylene carbonate derivative substituted with a substituent having an aromatic ring or a carbon-carbon double bond, and the like can be given.

[0547] As the fluorinated vinylene carbonate derivative, 4-fluorovinylene carbonate, 4-fluoro-5-methylvinylene carbonate, 4-fluoro-5-phenylvinylene carbonate, 4-allyl-5-fluorovinylene carbonate, 4-fluoro-5-vinylvinylene carbonate, and the like can be given.

[0548] As the fluorinated ethylene carbonate derivative substituted with a substituent having an aromatic ring or a carbon-carbon double bond, 4-fluoro-4-vinylethylene carbonate, 4-fluoro-4-allylethylene carbonate, 4-fluoro-5-vinylethylene carbonate, 4-fluoro-5-allylethylene carbonate, 4,4-difluoro-4-vinylethylene carbonate, 4,4-difluoro-4-allylethylene carbonate, 4,5-difluoro-4-vinylethylene carbonate, 4,5-difluoro-4-allylethylene carbonate, 4-fluoro-4,5-divinylethylene carbonate, 4-fluoro-4,5-diallylethylene carbonate, 4,5-difluoro-4,5-divinylethylene carbonate, 4,5-difluoro-4,5-diallylethylene carbonate, 4-fluoro-4-phenylethylene carbonate, 4-fluoro-5-phenylethylene carbonate, 4,4-difluoro-5-phenylethylene carbonate, 4,5-difluoro-4-phenylethylene carbonate, and the like can be given.

[0549] Among them, as the fluorinated unsaturated cyclic carbonate, the following compounds are more preferably used because a stable interface protective coating film is formed: 4-fluorovinylene carbonate, 4-fluoro-5-methylvinylene carbonate, 4-fluoro-5-vinylvinylene carbonate, 4-allyl-5-fluorovinylene carbonate, 4-fluoro-4-vinylethylene carbonate, 4-fluoro-4-allylethylene carbonate, 4-fluoro-5-vinylethylene carbonate, 4-fluoro-5-allylethylene carbonate, 4,4-difluoro-4-vinylethylene carbonate, 4,4-difluoro-4-allylethylene carbonate, 4,5-difluoro-4-vinylethylene carbonate, 4,5-difluoro-4-allylethylene carbonate, 4-fluoro-4,5-divinylethylene carbonate, 4-fluoro-4,5-diallylethylene carbonate, 4,5-difluoro-4,5-divinylethylene carbonate, 4,5-difluoro-4,5-diallylethylene carbonate.

[0550] The molecular weight of the fluorinated unsaturated cyclic carbonate is not particularly limited, and is an arbitrary molecular weight as long as the effect of the present application is not significantly impaired. The molecular weight is preferably 50 or greater and 500 or less. As long as it is within this range, the solubility of the fluorinated unsaturated cyclic carbonate with respect to the electrolytic solution is easily ensured.

[0551] The method for producing the fluorinated unsaturated cyclic carbonate is not particularly limited, and an arbitrary known method can be used for production. The molecular weight is more preferably 100 or greater, and furthermore, more preferably 200 or less.

[0552] The fluorinated unsaturated cyclic carbonate can be used alone or two or more kinds can be used in an arbitrary combination and ratio. In addition, the content of the fluorinated unsaturated cyclic carbonate is not particularly limited, and is an arbitrary content as long as the effect of the present application is not significantly impaired. The content of the fluorinated unsaturated cyclic carbonate is, in general, preferably 0.001% by mass or greater, more preferably 0.01% by mass or greater, and further preferably 0.1% by mass or greater, in 100% by mass of the electrolytic solution, and is preferably 5% by mass or less, more preferably 4% by mass or less, and further preferably 3% by mass or less. As long as it is within this range, the electrochemical device using the electrolytic solution easily exhibits a sufficient cycle characteristic improvement effect, and furthermore, a decrease in high-temperature storage characteristics, an increase in gas generation amount, and a decrease in discharge capacity maintenance rate are easily avoided.

[0553] In the case where the composition of the present application is used as an electrolytic solution, the composition of the present application can include a compound having a triple bond. The kind is not particularly limited as long as it is a compound having one or more triple bonds in the molecule.

[0554] As specific examples of the compound having a triple bond, for example, the following compounds can be given.

[0555] 1-pentyn-1-ol, 2-pentyn-1-ol, 1-hexyn-1-ol, 2-hexyn-1-ol, 3-hexyn-1-ol, 1-heptyn-1-ol, 2-heptyn-1-ol, 3-heptyn-1-ol, 1-octyn-1-ol, 2-octyn-1-ol, 3-octyn-1-ol, 4-octyn-1-ol, 1-nonyl-1-ol, 2-nonyl-1-ol, 3-nonyl-1-ol, 4-nonyl-1-ol, 1-dodecyn-1-ol, 2-dodecyn-1-ol, 3-dodecyn-1-ol, 4-dodecyn-1-ol, 5-dodecyn-1-ol, phenylacetylene, 1-phenyl-1-propyne, 1-phenyl-2-propyne, 1-phenyl-1-butyn, 4-phenyl-1-butyn, 4-phenyl-1-butyn, 1-phenyl-1-pentyn, 5-phenyl-1-pentyn, 1-phenyl-1-hexyn, 6-phenyl-1-hexyn, diphenylacetylene, 4-ethynyltoluene, dicyclohexylacetylene, and the like hydrocarbon compounds;

[0556] monocarbonic acid esters such as 2-propynylmethyl carbonate, 2-propynylethyl carbonate, 2-propynylpropyl carbonate, 2-propynylbutyl carbonate, 2-propynylphenyl carbonate, 2-propynylcyclohexyl carbonate, di(2-propynyl) carbonate, 1-methyl-2-propynylmethyl carbonate, 1,1-dimethyl-2-propynylmethyl carbonate, 2-butynylmethyl carbonate, 3-butynylmethyl carbonate, 2-pentynylmethyl carbonate, 3-pentynylmethyl carbonate, 4-pentynylmethyl carbonate, and the like; dicarbonic acid esters such as 2-butyn-1,4-diol dimethyl dicarbonate, 2-butyn-1,4-diol diethyl dicarbonate, 2-butyn-1,4-diol dipropyl dicarbonate, 2-butyn-1,4-diol dibutyl dicarbonate, 2-butyn-1,4-diol diphenyl dicarbonate, 2-butyn-1,4-diol dicyclohexyl dicarbonate, and the like;

[0557] 2-propynyl acetate, 2-propynyl propionate, 2-propynyl butyrate, 2-propynyl benzoate, 2-propynyl cyclohexanecarboxylate, 1,1-dimethyl-2-propynyl acetate, 1,1-dimethyl-2-propynyl propionate, 1,1-dimethyl-2-propynyl butyrate, 1,1-dimethyl-2-propynyl benzoate, 1,1-dimethyl-2-propynyl cyclohexanecarboxylate, 2-butynyl acetate, 3-butynyl acetate, 2-pentynyl acetate, 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, vinyl methacrylate, 2-propenyl methacrylate, 2-butenyl methacrylate, 3-butenyl methacrylate, methyl 2-propynoate, ethyl 2-propynoate, propyl 2-propynoate, vinyl 2-propynoate, 2-propenyl 2-propynoate, 2-butenyl 2-propynoate, 3-butenyl 2-propynoate, methyl 2-butynoate, ethyl 2-butynoate, propyl 2-butynoate, vinyl 2-butynoate, 2-propenyl 2-butynoate, 2-butenyl 2-butynoate, 3-butenyl 2-butynoate, methyl 3-butynoate, ethyl 3-butynoate, propyl 3-butynoate, vinyl 3-butynoate, 2-propenyl 3-butynoate, 2-butenyl 3-butynoate, 3-butenyl 3-butynoate, methyl 2-pentynoate, ethyl 2-pentynoate, propyl 2-pentynoate, vinyl 2-pentynoate, 2-propenyl 2-pentynoate, 2-butenyl 2-pentynoate, 3-butenyl 2-pentynoate, methyl 3-pentynoate, ethyl 3-pentynoate, propyl 3-pentynoate, vinyl 3-pentynoate, 2-propenyl 3-pentynoate, 2-butenyl 3-pentynoate, 3-butenyl 3-pentynoate, methyl 4-pentynoate, ethyl 4-pentynoate, propyl 4-pentynoate, vinyl 4-pentynoate, 2-propenyl 4-pentynoate, 2-butenyl 4-pentynoate, 3-butenyl 4-pentynoate, and the like mono carboxylic acid esters, fumarate esters, methyl trimethylacetate, ethyl trimethylacetate;

[0558] 2-butyn-1,4-diol diacetate, 2-butyn-1,4-diol dipropionate, 2-butyn-1,4-diol dibutyrate, 2-butyn-1,4-diol dibenzoate, 2-butyn-1,4-diol dicyclohexanecarboxylate, hexahydrobenzo[1,3,2]dioxathiolane-2-oxide (1,2-cyclohexanediol, 2,2-dioxo-1,2-oxathiolan-4-yl acetate, 2,2-dioxo-1,2-oxathiolan-4-yl acetate, and the like di carboxylic acid esters;

[0559] oxalate diesters such as monomethyl mono-2-propynyl oxalate, monoethyl mono-2-propynyl oxalate, monopropyl mono-2-propynyl oxalate, mono-2-propynyl mono-vinyl oxalate, monoallyl mono-2-propynyl oxalate, di(2-propynyl) oxalate, mono-2-butynyl mono-methyl oxalate, mono-2-butynyl mono-ethyl oxalate, mono-2-butynyl mono-propyl oxalate, mono-2-butynyl mono-vinyl oxalate, monoallyl mono-2-butynyl oxalate, di(2-butynyl) oxalate, mono-3-butynyl mono-methyl oxalate, mono-3-butynyl mono-ethyl oxalate, mono-3-butynyl mono-propyl oxalate, mono-3-butynyl mono-vinyl oxalate, monoallyl mono-3-butynyl oxalate, di(3-butynyl) oxalate, and the like;

[0560] methyl(2-propynyl)(vinyl)phosphine oxide, di(vinyl)(2-propynyl)phosphine oxide, di(2-propynyl)(vinyl)phosphine oxide, di(2-propenyl)(2-propynyl)phosphine oxide, di(2-propynyl)(2-propenyl)phosphine oxide, di(3-butenyl)(2-propynyl)phosphine oxide, and di(2-propynyl)(3-butenyl)phosphine oxide, and the like phosphine oxides;

[0561] methyl(2-propenyl)phosphinate 2-propynyl ester, 2-butenyl(methyl)phosphinate 2-propynyl ester, di(2-propenyl)phosphinate 2-propynyl ester, di(3-butenyl)phosphinate 2-propynyl ester, methyl(2-propenyl)phosphinate 1,1-dimethyl-2-propynyl ester, 2-butenyl(methyl)phosphinate 1,1-dimethyl-2-propynyl ester, di(2-propenyl)phosphinate 1,1-dimethyl-2-propynyl ester, and di(3-butenyl)phosphinate 1,1-dimethyl-2-propynyl ester, methyl(2-propynyl)phosphinate 2-propenyl ester, methyl(2-propynyl)phosphinate 3-butenyl ester, di(2-propynyl)phosphinate 2-propenyl ester, di(2-propynyl)phosphinate 3-butenyl ester, 2-propynyl(2-propenyl)phosphinate 2-propenyl ester, and 2-propynyl(2-propenyl)phosphinate 3-butenyl ester, and the like phosphinate esters;

[0562] 2-propenylphosphonic acid (methyl) (2-propynyl) ester, 2-but enylphosphonic acid (methyl) (2-propynyl) ester, 2-propenylphosphonic acid (2-propynyl) (2-propenyl) ester, 3-but enylphosphonic acid (3-but enyl) (2-propynyl) ester, 2-propenylphosphonic acid (1,1-dimethyl-2-propynyl) (methyl) ester, 2-but enylphosphonic acid (1,1-dimethyl-2-propynyl) (methyl) ester, 2-propenylphosphonic acid (1,1-dimethyl-2-propynyl) (2-propenyl) ester, 3-but enylphosphonic acid (3-but enyl) (1,1-dimethyl-2-propynyl) ester, methylphosphonic acid (2-propynyl) (2-propenyl) ester, methylphosphonic acid (3-but enyl) (2-propynyl) ester, methylphosphonic acid (1,1-dimethyl-2-propynyl) (2-propenyl) ester, methylphosphonic acid (3-but enyl) (1,1-dimethyl-2-propynyl) ester, ethylphosphonic acid (2-propynyl) (2-propenyl) ester, ethylphosphonic acid (3-but enyl) (2-propynyl) ester, ethylphosphonic acid (1,1-dimethyl-2-propynyl) (2-propenyl) ester, and ethylphosphonic acid (3-but enyl) (1,1-dimethyl-2-propynyl) ester, and the like phosphonate esters;

[0563] (methyl) (2-propynyl) ester, phosphoric acid (ethyl) (2-propynyl) ester, phosphoric acid (2-but enyl) (methyl) (2-propynyl) ester, phosphoric acid (2-but enyl) (ethyl) (2-propynyl) ester, phosphoric acid (1,1-dimethyl-2-propynyl) (methyl) (2-propynyl) ester, phosphoric acid (1,1-dimethyl-2-propynyl) (ethyl) (2-propynyl) ester, phosphoric acid (2-but enyl) (1,1-dimethyl-2-propynyl) (methyl) ester, and phosphoric acid (2-but enyl) (ethyl) (1,1-dimethyl-2-propynyl) ester, and the like phosphoric acid esters.

[0564] Among these, the compounds having an alkynoxy group are more stable in the electrolytic solution to form a negative electrode film, and thus are preferred.

[0565] Furthermore, from the viewpoint of improving storage characteristics, 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 2-propynyl oxalate, di(2-propynyl) oxalate, and the like compounds are particularly preferred.

[0566] The compound having a triple bond described above can be used singly, or two or more kinds thereof can be used in any combination and at any ratio. The amount of the compound having a triple bond to be blended with respect to the entire electrolyte is not limited, and is any amount as long as the effect of the present application is not significantly impaired. In general, the compound having a triple bond is contained in the electrolyte at a concentration of usually 0.01 mass% or more, preferably 0.05 mass% or more, more preferably 0.1 mass% or more, and also usually 5 mass% or less, preferably 3 mass% or less, more preferably 1 mass% or less. When the above range is satisfied, the effects of output characteristics, load characteristics, cycle characteristics, high-temperature storage characteristics, and the like are further improved.

[0567] In the case where the composition of the present application is used as an electrolyte, in order to effectively suppress the rupture and ignition of a battery when an electrochemical device using the electrolyte becomes an overcharged state or the like, the composition of the present application can use an overcharge inhibitor.

[0568] As the overcharge-preventing agent, there can be mentioned unsubstituted or alkyl-substituted triphenyl derivatives such as biphenyl, o-triphenyl, m-triphenyl, p-triphenyl, partial hydrogenates of unsubstituted or alkyl-substituted triphenyl derivatives, cyclohexylbenzene, t-butylbenzene, t-amylbenzene, diphenyl ether, dibenzofuran, diphenylcyclohexane, 1,1,3-trimethyl-3-phenylindan, cyclopentylbenzene, cyclohexylbenzene, cumene, 1,3-diisopropylbenzene, 1,4-diisopropylbenzene, t-butylbenzene, t-amylbenzene, t-hexylbenzene, anisole and the like aromatic compounds; partial fluorides of the above aromatic compounds such as 2-fluorobiphenyl, 4-fluorobiphenyl, o-cyclohexylfluorobenzene, p-cyclohexylfluorobenzene, o-cyclohexylfluorobenzene, p-cyclohexylfluorobenzene fluorobenzene, fluorotoluene, trifluorotoluene and the like; fluorine-containing anisole compounds such as 2,4-difluoroanisole, 2,5-difluoroanisole, 1,6-difluoroanisole, 2,6-difluoroanisole, 3,5-difluoroanisole and the like; aromatic acetates such as 3-propylphenyl acetate, 2-ethylphenyl acetate, benzylphenyl acetate, methylphenyl acetate, benzyl acetate, phenethylphenyl acetate and the like; aromatic carbonates such as diphenyl carbonate, phenylmethyl carbonate and the like; toluene derivatives such as toluene, xylene and the like; unsubstituted or alkyl-substituted biphenyl derivatives such as 2-methylbiphenyl, 3-methylbiphenyl, 4-methylbiphenyl, o-cyclohexylbiphenyl and the like. Among them, preferred are biphenyl, alkylbiphenyl, triphenyl, partial hydrogenates of triphenyl, cyclohexylbenzene, t-butylbenzene, t-amylbenzene, diphenyl ether, dibenzofuran and the like aromatic compounds; diphenylcyclohexane, 1,1,3-trimethyl-3-phenylindan, 3-propylphenyl acetate, 2-ethylphenyl acetate, benzyl phenylacetate, methylphenyl acetate, benzyl acetate, diphenyl carbonate, phenylmethyl carbonate and the like. They can be used singly or in combination of two or more. In the case of using two or more in combination, from the viewpoint of the balance between the overcharge-preventing property and the high-temperature storage property, particularly preferred is the combination of cyclohexylbenzene with t-butylbenzene or t-amylbenzene; the combination of at least one selected from the group consisting of biphenyl, alkylbiphenyl, triphenyl, partial hydrogenates of triphenyl, cyclohexylbenzene, t-butylbenzene, t-amylbenzene and the like non-oxygen-containing aromatic compounds with at least one selected from the group consisting of diphenyl ether, dibenzofuran and the like oxygen-containing aromatic compounds.

[0569] The electrolyte solution used in the present application can use a carboxylic anhydride (wherein, except for the compound (4)). As the carboxylic anhydride, a compound represented by the following general formula (6) is preferred. The method of producing the carboxylic anhydride is not particularly limited, and a publicly known method can be arbitrarily selected.

[0570] [Chemical Formula 62]

[0571]

[0572] In the general formula (6), R 61 , R 62each independently represents a hydrocarbon group having 1 or more and 15 or less carbon atoms which can have a substituent.

[0573] R 61 , R 62 There is no particular limitation as long as it is a monovalent hydrocarbon group. For example, it can be an aliphatic hydrocarbon group, or an aromatic hydrocarbon group, or a group in which an aliphatic hydrocarbon group and an aromatic hydrocarbon group are bonded. The aliphatic hydrocarbon group can be a saturated hydrocarbon group, or can contain an unsaturated bond (carbon-carbon double bond or carbon-carbon triple bond). In addition, the aliphatic hydrocarbon group can be chain-like or cyclic, and in the case of being chain-like, it can be straight-chain, or branched-chain. Furthermore, it can be a group in which a chain-like and a cyclic are bonded. Note that R 61 and R 62 may be the same as each other, or different from each other.

[0574] In addition, in the case where the hydrocarbon group of R 61 , R 62 has a substituent, the kind of the substituent is not particularly limited as long as it does not depart from the gist of the present application, and as examples, halogen atoms such as a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom can be given, and a fluorine atom is preferred. Or as a substituent other than a halogen atom, a substituent having a functional group such as an ester group, a cyano group, a carbonyl group, and an ether group can be given, and a cyano group and a carbonyl group are preferred. R 61 , R 62 The hydrocarbon group of R 61 , R 62 may have one of these substituents, or two or more of these substituents. In the case where two or more of these substituents are present, they can be the same as each other, or different from each other.

[0575] R 61 , R 62 The number of carbon atoms of each of the hydrocarbon groups is usually 1 or more, and in addition, usually 15 or less, preferably 12 or less, more preferably 10 or less, and further preferably 9 or less. In the case where R 61 and R 62 are bonded to each other to form a divalent hydrocarbon group, the number of carbon atoms of the divalent hydrocarbon group is usually 1 or more, and in addition, usually 15 or less, preferably 13 or less, more preferably 10 or less, and further preferably 8 or less. Note that in the case where the hydrocarbon group of R 61 , R 62 has a substituent containing a carbon atom, the number of carbon atoms of R 61 , R 62 as a whole including the substituent satisfies the above range.

[0576] Next, specific examples of the acid anhydride represented by the above general formula (6) will be described. Note that in the following examples, "analog" means an acid anhydride obtained by replacing a part of the structure of the exemplified acid anhydride with another structure within a range not deviating from the gist of the present application, and examples thereof include dimers, trimers, tetramers, and the like composed of a plurality of acid anhydrides, or structural isomers having the same number of carbon atoms in the substituents but having a branched chain, and the like, or substances having different bonding sites of the substituents to the acid anhydride.

[0577] First, the following exemplifies R 61 , R 62 , and the like.

[0578] As specific examples of the acid anhydride in which R 61 , R 62 is a linear alkyl group, there can be mentioned acetic anhydride, propionic anhydride, butyric anhydride, 2-methylpropionic anhydride, 2,2-dimethylpropionic anhydride, 2-methylbutyric anhydride, 3-methylbutyric anhydride, 2,2-dimethylbutyric anhydride, 2,3-dimethylbutyric anhydride, 3,3-dimethylbutyric anhydride, 2,2,3-trimethylbutyric anhydride, 2,3,3-trimethylbutyric anhydride, 2,2,3,3-tetramethylbutyric anhydride, 2-ethylbutyric anhydride, and the like, and analogs thereof.

[0579] As specific examples of the acid anhydride in which R 61 , R 62 is a cyclic alkyl group, there can be mentioned cyclopropane carboxylic anhydride, cyclopentane carboxylic anhydride, cyclohexane carboxylic anhydride, and the like, and analogs thereof.

[0580] As specific examples of the acid anhydride in which R 61 , R 62 is an alkenyl group, there can be mentioned acrylic anhydride, 2-methylacrylic anhydride, 3-methylacrylic anhydride, 2,3-dimethylacrylic 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-butenoic anhydride, 2-methyl-3-methyl-3-butenoic anhydride, 2,2-dimethyl-3-methyl-3-butenoic anhydride, 3-pentenoic anhydride, 4-pentenoic anhydride, 2-cyclopentenecarboxylic anhydride, 3-cyclopentenecarboxylic anhydride, 4-cyclopentenecarboxylic anhydride, and the like, and analogs thereof.

[0581] As specific examples of the acid anhydride in which R 61 , R 62 is an alkynyl group, there can be mentioned propynoic anhydride, 3-phenylpropynoic anhydride, 2-butynoic anhydride, 2-pentynoic anhydride, 3-butynoic anhydride, 3-pentynoic anhydride, 4-pentynoic anhydride, and the like, and analogs thereof.

[0582] as R 61 , R 62 as an acid anhydride substituted with a halogen atom, examples of an acid anhydride mainly substituted with a fluorine atom are given below, but acid anhydrides obtained by substituting some or all of these fluorine atoms with chlorine atoms, bromine atoms, iodine atoms are also included in the exemplified compounds.

[0583] Further, as R 61 , R 62 as an acid anhydride substituted with a halogen atom, examples of an acid anhydride mainly substituted with a fluorine atom are given below, but acid anhydrides obtained by substituting some or all of these fluorine atoms with chlorine atoms, bromine atoms, iodine atoms are also included in the exemplified compounds.

[0584] Further, as R 61 , R 62 as an acid anhydride substituted with a halogen atom, examples of an acid anhydride mainly substituted with a fluorine atom are given below, but acid anhydrides obtained by substituting some or all of these fluorine atoms with chlorine atoms, bromine atoms, iodine atoms are also included in the exemplified compounds.

[0585] Further, as R 61 , R 62 as an acid anhydride substituted with a halogen atom, examples of an acid anhydride mainly substituted with a fluorine atom are given below, but acid anhydrides obtained by substituting some or all of these fluorine atoms with chlorine atoms, bromine atoms, iodine atoms are also included in the exemplified compounds.

[0586] Further, as R 61 , R 62 as an acid anhydride substituted with a halogen atom, examples of an acid anhydride mainly substituted with a fluorine atom are given below, but acid anhydrides obtained by substituting some or all of these fluorine atoms with chlorine atoms, bromine atoms, iodine atoms are also included in the exemplified compounds.

[0587] Further, as R 61 , R62 Examples of the acid anhydride of the alkyne group substituted with a halogen atom include 3-fluoro-2-propynic anhydride, 3-(4-fluorophenyl)-2-propynic anhydride, 3-(2,3,4,5,6-pentafluorophenyl)-2-propynic anhydride, 4-fluoro-2-butynic anhydride, 4,4-difluoro-2-butynic anhydride, 4,4,4-trifluoro-2-butynic anhydride, and the like, and their analogs and the like.

[0588] Examples of R 61 Examples of R 62 Examples of the acid anhydride of the aryl group substituted with a halogen atom include 4-fluorobenzoic anhydride, 2,3,4,5,6-pentafluorobenzoic anhydride, 4-trifluoromethylbenzoic anhydride, and the like, and their analogs and the like.

[0589] Examples of R 61 Examples of R 62 Examples of the acid anhydride of the substituent having a functional group such as an ester, a nitrile, a ketone, an ether, and the like include methoxymethanoic anhydride, ethoxymethanoic anhydride, methyloxymethanoic anhydride, ethyl oxymethanoic anhydride, 2-cyanoethanoic anhydride, 2-oxopropanoic anhydride, 3-oxobutanoic anhydride, 4-acetylbenzoic anhydride, methoxyethanoic anhydride, 4-methoxybenzoic anhydride, and the like, and their analogs and the like.

[0590] Next, specific examples of the acid anhydride in which R 61 Examples of R 62 are different from each other are shown below.

[0591] Considering all combinations of the above examples of R 61 Examples of R 62 and their analogs, representative examples are shown below.

[0592] Examples of the combination of the chain alkyl groups with each other include acetic propionic anhydride, acetic butyric anhydride, butyric propionic anhydride, acetic 2-methylpropionic anhydride, and the like.

[0593] Examples of the combination of the chain alkyl group and the cyclic alkyl group include acetic cyclopentanoic anhydride, acetic cyclohexanoic anhydride, cyclopentanoic propionic anhydride, and the like.

[0594] Examples of the combination of the chain alkyl group and the alkenyl group include acetic acryl anhydride, acetic 3-methylacryl anhydride, acetic 3-butenyl anhydride, acryl propionic anhydride, and the like.

[0595] Examples of the combination of the chain alkyl group and the alkynyl group include acetic propynic anhydride, acetic 2-butynic anhydride, acetic 3-butynic anhydride, acetic 3-phenylpropynic anhydride, propynic propionic anhydride, and the like.

[0596] Examples of the combination of the chain alkyl group and the aryl group include acetic benzoic anhydride, acetic 4-methylbenzoic anhydride, acetic 1-naphthalene carboxylic anhydride, benzoic propionic anhydride, and the like.

[0597] As an example of the combination of the chain alkyl group and the hydrocarbon group having a functional group, there are mentioned fluoroacetic anhydride, trifluoroacetic anhydride, 4-fluorobenzoic anhydride, propionic anhydride, alkyl oxalic anhydride, 2-cyanoacetic anhydride, 2-oxopropanoic anhydride, methoxyacetic anhydride, and methoxypropionic anhydride.

[0598] As an example of the combination of the cyclic alkyl group and the cyclic alkyl group, there are mentioned cyclopentanoic anhydride, cyclohexanoic anhydride, and the like.

[0599] As an example of the combination of the cyclic alkyl group and the alkenyl group, there are mentioned cyclopentanoic propenoic anhydride, 3-methylcyclopentanoic 3-methylpropenoic anhydride, 3-butenoic cyclopentanoic anhydride, cyclohexanoic propenoic anhydride, and the like.

[0600] As an example of the combination of the cyclic alkyl group and the alkynyl group, there are mentioned cyclopentanoic propynoic anhydride, 2-butynoic cyclopentanoic anhydride, cyclohexanoic propynoic anhydride, and the like.

[0601] As an example of the combination of the cyclic alkyl group and the aryl group, there are mentioned cyclopentanoic benzoic anhydride, 4-methylcyclopentanoic benzoic anhydride, cyclohexanoic benzoic anhydride, and the like.

[0602] As an example of the combination of the cyclic alkyl group and the hydrocarbon group having a functional group, there are mentioned cyclopentanoic fluoroacetic anhydride, trifluoroacetic cyclopentanoic anhydride, 2-cyanoacetic cyclopentanoic anhydride, methoxyacetic cyclopentanoic anhydride, and cyclohexanoic fluoroacetic anhydride.

[0603] As an example of the combination of the alkenyl group and the alkenyl group, there are mentioned 2-methylpropenoic anhydride, 3-methylpropenoic anhydride, 3-butenoic anhydride, 3-methylpropenoic 2-methylpropenoic anhydride, and the like.

[0604] As an example of the combination of the alkenyl group and the alkynyl group, there are mentioned propenoic propynoic anhydride, 2-butynoic propenoic anhydride, propynoic 2-methylpropenoic anhydride, and the like.

[0605] As an example of the combination of the alkenyl group and the aryl group, there are mentioned propenoic benzoic anhydride, 4-methylpropenoic benzoic anhydride, benzoic 2-methylpropenoic anhydride, and the like.

[0606] As an example of the combination of the alkenyl group and the hydrocarbon group having a functional group, there are mentioned propenoic fluoroacetic anhydride, trifluoroacetic propenoic anhydride, 2-cyanoacetic propenoic anhydride, methoxyacetic propenoic anhydride, and 2-methylpropenoic fluoroacetic anhydride.

[0607] As an example of the combination of the alkynyl group and the alkynyl group, there are mentioned 2-butynoic anhydride, 3-butynoic anhydride, 3-butynoic 2-butynoic anhydride, and the like.

[0608] As an example of the combination of the alkynyl group and the aryl group, benzoic anhydride, 4-methylbenzoic anhydride, 2-butynic anhydride, and the like can be given.

[0609] As an example of the combination of the alkynyl group and the hydrocarbon group having a functional group, propynic anhydride, 2-butynic anhydride, and the like can be given.

[0610] As an example of the combination of the aryl group and the hydrocarbon group having a functional group, benzoic anhydride, 4-methylbenzoic anhydride, 1-naphthoic anhydride, 4-methylbenzoic anhydride, and the like can be given.

[0611] As an example of the combination of the aryl group and the hydrocarbon group having a functional group, benzoic anhydride, 4-methylbenzoic anhydride, 1-naphthoic anhydride, 4-methylbenzoic anhydride, and the like can be given.

[0612] As an example of the combination of the aryl group and the hydrocarbon group having a functional group, benzoic anhydride, 4-methylbenzoic anhydride, 1-naphthoic anhydride, 4-methylbenzoic anhydride, and the like can be given.

[0613] Among the anhydrides described above, acetic anhydride, propionic anhydride, 2-methylpropionic anhydride, cyclopentanoic anhydride, cyclohexanoic anhydride, acrylic anhydride, 2-methylacrylic anhydride, 3-methylacrylic anhydride, 2,3-dimethylacrylic anhydride, 3,3-dimethylacrylic anhydride, 3-butenoic anhydride, 2-methyl-3-butenoic anhydride, propynic anhydride, 2-butynic anhydride, benzoic anhydride, 2-methylbenzoic anhydride, 4-methylbenzoic anhydride, 4-tert-butylbenzoic anhydride, trifluoroacetic anhydride, 3,3,3-trifluoropropionic anhydride, 2-(trifluoromethyl)acrylic anhydride, 2-(4-fluorophenyl)acrylic anhydride, 4-fluorobenzoic anhydride, 2,3,4,5,6-pentafluorobenzoic anhydride, methoxyformic anhydride, ethoxyformic anhydride are preferable; and acrylic anhydride, 2-methylacrylic anhydride, 3-methylacrylic anhydride, benzoic anhydride, 2-methylbenzoic anhydride, 4-methylbenzoic anhydride, 4-tert-butylbenzoic anhydride, 4-fluorobenzoic anhydride, 2,3,4,5,6-pentafluorobenzoic anhydride, methoxyformic anhydride, ethoxyformic anhydride are more preferable.

[0614] These compounds form a film having excellent durability by forming a bond with the lithium oxalate salt as appropriate, and are particularly preferable from the viewpoint of being able to improve the charge-discharge rate characteristics, input-output characteristics, and impedance characteristics after the durability test.

[0615] Further, the molecular weight of the above carboxylic anhydride is not limited, and is an arbitrary molecular weight as long as the effect of the present application is not significantly impaired, but is usually 90 or more, preferably 95 or more, and on the other hand, is usually 300 or less, preferably 200 or less. If the molecular weight of the carboxylic anhydride is within the above range, the viscosity of the electrolyte solution can be suppressed from increasing, and the film density is optimized, and thus the durability can be appropriately improved.

[0616] Further, the method of producing the above carboxylic anhydride is not particularly limited, and a publicly known method can be arbitrarily selected for the production. The above-described carboxylic anhydride can be contained alone in the nonaqueous electrolyte solution of the present application, or two or more kinds can be contained in an arbitrary combination and ratio.

[0617] The content of the above carboxylic anhydride with respect to the electrolyte solution is not particularly limited, and is an arbitrary content as long as the effect of the present application is not significantly impaired, but is usually 0.01% by mass or more, preferably 0.1% by mass or more, and on the other hand, is usually 5% by mass or less, preferably 3% by mass or less. If the content of the carboxylic anhydride is within the above range, the effect of improving the cycle characteristics is easily exerted, and the reactivity is good, and thus the battery characteristics are easily improved.

[0618] In the case where the composition of the present application is used as an electrolyte solution, the composition of the present application can use publicly known other additives. As the other additives, there are mentioned hydrocarbon compounds such as pentane, heptane, octane, nonane, decane, cycloheptane, benzene, furan, naphthalene, 2-phenylcyclohexane, cyclohexane, 2,4,8,10-tetraoxaspiro[5.5]undecane, 3,9-divinyl-2,4,8,10-tetraoxaspiro[5.5]undecane, and the like;

[0619] fluorobenzene, difluorobenzene, hexafluorobenzene, trifluorotoluene, monofluorobenzene, 1-fluoro-2-cyclohexylbenzene, 1-fluoro-4-tert-butylbenzene, 1-fluoro-3-cyclohexylbenzene, 1-fluoro-2-cyclohexylbenzene, fluorobiphenyl, and the like fluorine-containing aromatic compounds;

[0620] carbonate compounds such as dehydrated erythritan carbonate, spirobis-dimethylene carbonate, methoxyethyl-methyl carbonate, and the like;

[0621] ether compounds such as dioxolane, dioxane, 2,5,8,11-tetraoxadodecane, 2,5,8,11,14-pentaoxapentadecane, ethoxymethoxyethane, trimethoxymethane, ethylene glycol dimethyl ether, ethylene glycol diethyl ether (ethyl monoglyme), and the like

[0622] ketone compounds such as dimethyl ketone, diethyl ketone, 3-pentanone, and the like;

[0623] anhydrides such as 2-allylsuccinic anhydride, and the like;

[0624] dimethyl oxalate, diethyl oxalate, methyl ethyl oxalate, di(2-propynyl) oxalate, monomethyl mono-2-propynyl oxalate, dimethyl succinate, di(2-propynyl) glutarate, methyl formate, ethyl formate, 2-propynyl formate, 2-butyn-l,4-diyl diformate, 2-propynyl methacrylate, dimethyl malonate, and the like ester compounds

[0625] acetamide, N-methyl formamide, N,N-dimethyl formamide, N,N-dimethyl acetamide, and the like amide compounds;

[0626] ethyl sulfite, ethylene sulfite, ethylene sulfite, methyl fluorosulfonate, ethyl fluorosulfonate, methyl methanesulfonate, ethyl methanesulfonate, busulfan, cyclobutene sulfone, diphenyl sulfone, N,N-dimethyl methanesulfonamide, N,N-diethyl methanesulfonamide, methyl vinyl sulfonate, ethyl vinyl sulfonate, allyl vinyl sulfonate, propargyl vinyl sulfonate, methyl allyl sulfonate, ethyl allyl sulfonate, propargyl allyl sulfonate, 1,2-bis(vinylsulfonyloxy)ethane, propane disulfonic anhydride, sulfobutyric anhydride, sulfobenzoic anhydride, sulfopropionic anhydride, ethane disulfonic anhydride, methanedisulfonic methylene ester, methanesulfonic acid-2-propyn-l-ol, pentylene sulfite, pentafluorophenyl methanesulfonate, propylene sulfite, propylene sulfite, propyl sulfone, butylene sulfite, (butane-2,3-diyl)dimethanesulfonate, (2-butyn-l,4-diyl)dimethanesulfonate, (2-propynyl) vinyl sulfonate, bis(2-vinylsulfonyl ethyl) ether, 5-vinyl-hexahydro-l,3,2-benzodioxathiol-2-oxide, 2-propynyl 2-(methylsulfonyloxy)propionate, 5,5-dimethyl-l,2-oxathiolan-4-one 2,2-dioxide, 3-sulfo-propionic anhydride methanedisulfonic acid trimethylene ester 2-methyltetrahydrofuran, methanedisulfonic acid trimethylene ester, tetramethylene sulfoxide, methanedisulfonic acid dimethylene ester, difluoroethyl methyl sulfone, divinyl sulfone, 1,2-bis(vinylsulfonyl)ethane, ethylene bisphosphonate methyl ester, ethylene bisphosphonate ethyl ester, ethylene sulfite, thiophene-1-oxide, and the like sulfur-containing compounds;

[0627] 1-methyl-2-pyrrolidinone, 1-methyl-2-piperidinone, 3-methyl-2-oxazolidinone, 1,3-dimethyl-2-imidazolidinone, N-methyl succinimide, nitromethane, nitroethane, ethylenediamine, and the like nitrogen-containing compounds;

[0628] trimethyl phosphite, triethyl phosphite, triphenyl phosphite, trimethyl phosphate, triethyl phosphate, triphenyl phosphate, dimethyl methylphosphonate, diethyl ethylphosphonate, dimethyl vinylphosphonate, diethyl vinylphosphonate, ethyl diethylphosphonoacetate, methyl dimethylphosphonoacetate, trimethyl phosphine oxide, triethyl phosphine oxide, bis(2,2-difluoroethyl) 2,2,2-trifluoroethyl phosphate, bis(2,2,3,3-tetrafluoropropyl) 2,2,2-trifluoroethyl phosphate, bis(2,2,2-trifluoroethyl) methyl phosphate, bis(2,2,2-trifluoroethyl) ethyl phosphate, bis(2,2,2-trifluoroethyl) 2,2-difluoroethyl phosphate, bis(2,2,2-trifluoroethyl) 2,2,3,3-tetrafluoropropyl phosphate, tributyl phosphate, tris(2,2,2-trifluoroethyl) phosphate, tris(1,1,1,3,3,3-hexafluoropropan-2-yl) phosphate, trioctyl phosphate, 2-phenylphenyldimethyl phosphate, 2-phenylphenyldiethyl phosphate, (2,2,2-trifluoroethyl)(2,2,3,3-tetrafluoropropyl)methyl phosphate, methyl 2-(dimethoxyphosphoryl)acetate, methyl 2-(dimethylphosphoryl)acetate, methyl 2-(diethoxyphosphoryl)acetate, methyl 2-(diethylphosphoryl)acetate, methylenebisphosphonic acid methyl ester, methylenebisphosphonic acid ethyl ester, ethylenebisphosphonic acid methyl ester, ethylenebisphosphonic acid ethyl ester, butylenebisphosphonic acid methyl ester, butylenebisphosphonic acid ethyl ester, 2-propynyl 2-(dimethoxyphosphoryl)acetate, 2-propynyl 2-(dimethylphosphoryl)acetate, 2-propynyl 2-(diethoxyphosphoryl)acetate, 2-propynyl 2-(diethylphosphoryl)acetate, tris(trimethylsilyl) phosphate, tris(triethylsilyl) phosphate, tris(trimethoxysilyl) phosphate, tris(trimethylsilyl) phosphite, tris(triethylsilyl) phosphite, tris(trimethoxysilyl) phosphite, trimethylsilyl trimethylphosphite, and the like phosphorus-containing compounds;

[0629] tris(trimethylsilyl) borate, tris(trimethoxysilyl) borate, and the like boron-containing compounds;

[0630] dimethanol trimethylaluminum silicate, diethanol triethylaluminum silicate, dipropyl alcohol triethylaluminum silicate, dibutanol trimethylaluminum silicate, dibutanol triethylaluminum silicate, tetrakis(trimethylsiloxy) titanium, tetrakis(triethylsiloxy) titanium, tetramethylsilane, and the like silane compounds;

[0631] and the like. They can be used singly or in combination of two or more. By adding these additives, the capacity maintenance characteristics or the cycle characteristics after high-temperature storage can be improved.

[0632] As the other additive described above, a phosphorus-containing compound is preferred, and tris(trimethylsilyl) phosphate, tris(trimethylsilyl) phosphite is preferred.

[0633] The blending amount of the other additive is not particularly limited, and is an arbitrary blending amount as long as the effect of the present application is not significantly impaired. The other additive is preferably 0.01% by mass or more and, in addition, 5% by mass or less in 100% by mass of the electrolyte. As long as it is within this range, the effect of the other additive is easily exhibited sufficiently, and it is also easy to avoid a decrease in the characteristics of the battery such as high-rate discharge characteristics. The blending amount of the other additive is more preferably 0.1% by mass or more, further preferably 0.2% by mass or more, and, in addition, more preferably 3% by mass or less, further preferably 1% by mass or less.

[0634] In the case where the composition of the present application is used as an electrolyte, the composition of the present application can further contain, within a range not impairing the effect of the present application, a cyclic and chain carboxylic acid ester, an ether compound (excluding compounds (1) and (2)), a nitrogen-containing compound, a boron-containing compound, an organosilicon-containing compound, a non-flammable (flame-retardant) agent, a surfactant, a high-dielectric additive, a cycle and rate characteristic improver, a sulfone-based compound, and the like as an additive.

[0635] As the cyclic carboxylic acid ester described above, a cyclic carboxylic acid ester having a total of 3 to 12 carbon atoms in the structural formula thereof can be given. Specifically, γ-butyrolactone, γ-valerolactone, γ-hexalactone, ε-hexalactone, 3-methyl-γ-butyrolactone, and the like can be given. Among them, γ-butyrolactone is particularly preferable from the viewpoint of the improvement in the characteristics of the electrochemical device resulting from the increase in the lithium ion dissociation degree.

[0636] Generally, the blending amount of the cyclic carboxylic acid ester as an additive is preferably 0.1% by mass or more, more preferably 1% by mass or more in 100% by mass of the solvent. If it is within this range, the conductivity of the electrolyte is improved, and it is easy to improve the large-current discharge characteristics of the electrochemical device. In addition, the blending amount of the cyclic carboxylic acid ester is preferably 10% by mass or less, more preferably 5% by mass or less. By setting the upper limit like this, the viscosity of the electrolyte is set to an appropriate range, the decrease in the conductivity is avoided, the increase in the negative electrode resistance is suppressed, and it is easy to set the large-current discharge characteristics of the electrochemical device to a good range.

[0637] In addition, as the cyclic carboxylic acid ester described above, a fluorinated cyclic carboxylic acid ester (fluorine-containing lactone) can also be suitably used. As the fluorine-containing lactone, for example, a fluorine-containing lactone represented by the following formula (C) can be given.

[0638] [Formula 63]

[0639]

[0640] (In the formula, X 15 ~X 20 are the same or different and are each -H, -F, -Cl, -CH3, or a fluoroalkyl group; and X15 at least one of X 20 in the formula (1) is a fluoroalkyl group.

[0641] as X 15 at least one of X 20 in the formula (1) is a fluoroalkyl group, for example, -CFH2, -CF2H, -CF3, -CH2CF3, -CF2CF3, -CH2CF2CF3, -CF(CF3)2, etc. can be mentioned, and from the viewpoint of high oxidation resistance and safety improvement effect, -CH2CF3, -CH2CF2CF3are preferred.

[0642] at least one of X 15 at least one of X 20 in the formula (1) is a fluoroalkyl group, -H, -F, -Cl, -CH3or a fluoroalkyl group can be substituted only in one position of X 15 at least one of X 20 in the formula (1), or can be substituted in a plurality of positions. From the viewpoint of good solubility of the electrolyte salt, 1 to 3 positions are preferred, and 1 to 2 positions are further preferred.

[0643] the substitution position of the fluoroalkyl group is not particularly limited, and from the viewpoint of good yield in synthesis, X 17 and / or X 18 , and particularly preferably X 17 or X 18 is a fluoroalkyl group, and among them, -CH2CF3, -CH2CF2CF3are preferred. X 15 at least one of X 20 in the formula (1) is -H, -F, -Cl or -CH3, and particularly from the viewpoint of good solubility of the electrolyte salt, -H is preferred.

[0644] as the fluorine-containing lactone, in addition to the fluorine-containing lactone represented by the above formula, for example, a fluorine-containing lactone represented by the following formula (D) or the like can be mentioned.

[0645] [Chem. 11]

[0646]

[0647] (In the formula, either one of A and B is CX 226 X 227 (X 226 and X 227 are the same or different, and each is -H, -F, -Cl, -CF3, -CH3or an alkylene group in which a hydrogen atom can be substituted with a halogen atom and can contain a hetero atom in the chain), and the other is an oxygen atom; Rf 12 is a fluorinated alkyl group or a fluorinated alkoxy group which can have an ether bond; X 221 and X 222the same or different, are each -H, -F, -Cl, -CF3, or CH3; X 223 ~ X 225 the same or different, are each -H, -F, -Cl, or an alkyl group which can be substituted with a halogen atom and can contain a hetero atom in the chain; n = 0 or 1)

[0648] As the fluorine-containing lactone represented by formula (D), a 5-membered ring structure represented by the following formula (E) can be given.

[0649] [Chemical Formula 65]

[0650]

[0651] (In the formula, A, B, Rf 12 , X 221 , X 222 , and X 223 are the same as formula (D))

[0652] However, from the aspect of easy synthesis and the aspect of good chemical stability, further, by the combination of A and B, a fluorine-containing lactone represented by the following formula (F) is preferable:

[0653] [Chemical Formula 66]

[0654]

[0655] (In the formula, Rf 12 , X 221 , X 222 , X 223 , X 226 , and X 227 are the same as formula (D))

[0656] and a fluorine-containing lactone represented by the following formula (G):

[0657] [Chemical Formula 67]

[0658]

[0659] (In the formula, Rf 12 , X 221 , X 222 , X 223 , X 226 , and X 227 are the same as formula (D)).

[0660] Among them, from the aspect that a high dielectric constant, high voltage resistance, and such excellent characteristics can be particularly exhibited, further, from the aspect that the solubility of electrolyte salts, the reduction of internal resistance, and such characteristics of the electrolytic solution in the present application are improved, a compound represented by the following formula (H) can be given:

[0661] [Chemical Formula 68]

[0662]

[0663] and the like.

[0664] By containing a fluorinated cyclic carboxylate, effects such as an increase in ion conductivity, an increase in safety, and an increase in stability at high temperatures are obtained.

[0665] As the above chain carboxylate, a substance having a total number of carbon atoms in the structural formula of 3 to 7 can be given. 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, n-propyl isobutyrate, isopropyl isobutyrate, and the like can be given.

[0666] Among them, from the viewpoint of improving ion conductivity by lowering viscosity, methyl acetate, ethyl acetate, n-propyl acetate, n-butyl acetate, methyl propionate, ethyl propionate, n-propyl propionate, isopropyl propionate, methyl butyrate, ethyl butyrate, and the like are preferable.

[0667] As the above ether compound, a chain ether having a number of carbon atoms of 2 to 10 and a cyclic ether having a number of carbon atoms of 3 to 6 are preferable.

[0668] As the chain ether having a number of carbon atoms of 2 to 10, dimethyl ether, diethyl ether, di-n-butyl ether, dimethoxymethane, methoxyethoxymethane, diethoxymethane, dimethoxyethane, methoxyethoxyethane, diethoxyethane, ethyleneglycol di-n-propyl ether, ethyleneglycol 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 can be given.

[0669] As the cyclic ether having a number of carbon atoms of 3 to 6, 1,2-dioxane, 1,3-dioxane, 2-methyl-1,3-dioxane, 4-methyl-1,3-dioxane, 1,4-dioxane, trioxane, 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 can be given. Among them, from the viewpoint of high solvating ability for lithium ions and an increase in ion dissociation degree, dimethoxymethane, diethoxymethane, ethoxymethoxy-methane, ethyleneglycol n-propyl ether, ethyleneglycol di-n-butyl ether, diethylene glycol dimethyl ether, crown ether are preferable; from the viewpoint of low viscosity and high ion conductivity, dimethoxymethane, diethoxymethane, ethoxymethoxymethane are particularly preferable.

[0670] As the above-mentioned nitrogen-containing compound, nitriles, fluorine-containing nitriles, carboxylic acid amides, fluorine-containing carboxylic acid amides, sulfonic acid amides and fluorine-containing sulfonic acid amides, acetamides, formamides and the like can be mentioned. In addition, 1-methyl-2-pyrrolidone, 1-methyl-2-piperidone, 3-methyl-2-oxazolidone, 1,3-dimethyl-2-imidazolidone and N-methylsuccinimide and the like can also be used. Among these, the nitrile compounds represented by the above-mentioned general formulae (1a), (1b) and (1c) are excluded from the above-mentioned nitrogen-containing compound.

[0671] As the above-mentioned boron-containing compound, for example, trimethyl borate, triethyl borate, boronic acid ethers and alkyl borate can be mentioned.

[0672] As the above-mentioned organosilicon compound, for example, (CH3)4-Si, (CH3)3-Si-Si(CH3)3, silicone oil and the like can be mentioned.

[0673] As the above-mentioned non-flammable (flame retardant) agent, phosphoric acid esters or phosphazene-based compounds can be mentioned. As the above-mentioned phosphoric acid ester, for example, fluorine-containing alkyl phosphates, non-fluorine-based alkyl phosphates, aryl phosphates and the like can be mentioned. Among these, in terms of being able to exert a non-flammable effect in a small amount, fluorine-containing alkyl phosphates are preferred.

[0674] As the above-mentioned phosphazene-based compound, for example, methoxy pentafluorocyclotriphosphazene, phenoxy pentafluorocyclotriphosphazene, dimethylamino pentafluorocyclotriphosphazene, diethylamino pentafluorocyclotriphosphazene, ethoxy pentafluorocyclotriphosphazene, ethoxy heptafluorocyclotetraphosphazene and the like can be mentioned.

[0675] As the above-mentioned fluorine-containing alkyl phosphate, specifically, fluorine-containing dialkyl phosphates disclosed in Japanese Patent Application Laid-Open No. 11-233141, cyclic alkyl phosphates disclosed in Japanese Patent Application Laid-Open No. 11-283669, or fluorine-containing trialkyl phosphates and the like can be mentioned.

[0676] As the above-mentioned non-flammable (flame retardant) agent, (CH3O)3P=O, (CF3CH2O)3P=O, (HCF2CH2O)3P=O, (CF3CF2CH2)3P=O, (HCF2CF2CH2)3P=O and the like are preferred.

[0677] As the above-mentioned surfactant, any one of a cationic surfactant, an anionic surfactant, a nonionic surfactant and an amphoteric surfactant can be used, and from the viewpoint of good cycle characteristics and rate characteristics, a surfactant containing a fluorine atom is preferred.

[0678] As such a surfactant containing a fluorine atom, for example, a fluorine-containing carboxylic acid salt represented by the following formula (30) is preferred:

[0679] Rf 5 COO - M + (30)

[0680] (incidentally, Rf 5 represents a fluorine-containing alkyl group which can have an ether linkage having 3 to 10 carbon atoms; M + represents Li + , Na + , K + or NHR'3 + (R' is the same or different, and each represents H or an alkyl group having 1 to 3 carbon atoms),

[0681] and a fluorine-containing sulfonate represented by the following formula (40) :

[0682] Rf 6 SO3 - M + (40)

[0683] (incidentally, Rf 6 represents a fluorine-containing alkyl group which can have an ether linkage having 3 to 10 carbon atoms; M + represents Li + , Na + , K + or NHR'3 + (R' is the same or different, and each represents H or an alkyl group having 1 to 3 carbon atoms),

[0684] and the like.

[0685] From the viewpoint of being able to reduce the surface tension of the electrolyte solution without reducing the charge / discharge cycle characteristics, the content of the above-mentioned surfactant in the electrolyte solution is preferably 0.01 to 2 mass %.

[0686] As the above-mentioned high dielectric constant additive, for example, sulfolane, methylsulfolane, γ-butyrolactone, γ-valerolactone and the like can be given.

[0687] As the above-mentioned cycle characteristics and rate characteristics improver, for example, methyl acetate, ethyl acetate, tetrahydrofuran, 1,4-dioxane and the like can be given.

[0688] In addition, in the case where the composition of the present application is used as an electrolyte solution, the composition of the present application can further be combined with a high molecular material to produce a gel electrolyte solution which is gelled (plasticized).

[0689] As such a high molecular material, there are, for example, polyoxyethylene, polyoxypropylene, and modified products thereof (Japanese Patent Application Laid-Open No. 8-222270, Japanese Patent Application Laid-Open No. 2002-100405); polyacrylate-based polymers, polyacrylonitrile, polyvinylidene fluoride, fluororesins such as vinylidene fluoride-hexafluoropropylene copolymer (Japanese Patent Application Laid-Open No. 4-506726, Japanese Patent Application Laid-Open No. 8-507407, Japanese Patent Application Laid-Open No. 10-294131); a composite of these fluororesins and a hydrocarbon resin (Japanese Patent Application Laid-Open No. 11-35765, Japanese Patent Application Laid-Open No. 11-86630), and the like. In particular, it is desirable to use polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer as a high molecular material for a gel electrolyte.

[0690] In the case where the composition of the present application is used as an electrolyte solution, the composition of the present application can further contain an ion-conducting compound described in Japanese Patent Application No. 2004-301934.

[0691] The ion-conducting compound is an amorphous fluorine-containing polyether compound having a side chain represented by formula (101) having a fluorine-containing group:

[0692] A-(D)-B (101)

[0693] [In the formula, D is an ether unit having a side chain represented by formula (201) having a fluorine-containing ether group:

[0694] -(D1) n -(FAE) m -(AE) p -(Y) q -(201)

[0695] (In the formula, D1 is an ether unit having a side chain represented by formula (2a) having a fluorine-containing ether group:

[0696] [Chemical Formula 69]

[0697]

[0698] (In the formula, Rf is a fluorine-containing ether group which can have a cross-linkable functional group, R 10 is a group or a chemical bond which bonds Rf to the main chain);

[0699] FAE is an ether unit having a side chain represented by formula (2b) having a fluoroalkyl group:

[0700] [Chemical Formula 70]

[0701]

[0702] (In the formula, Rfais a hydrogen atom, a fluorinated alkyl group which can have a crosslinkable functional group; R 11 a group or a bonding bond for bonding Rfaand the main chain);

[0703] AE is an ether unit represented by formula (2c):

[0704] [Chemical Formula 71]

[0705]

[0706] (In the formula, R 13 is a hydrogen atom, an alkyl group which can have a crosslinkable functional group, an alicyclic hydrocarbon group which can have a crosslinkable functional group, or an aromatic hydrocarbon group which can have a crosslinkable functional group; R 12 is a group or a bonding bond for bonding the main chain and R 13 ;

[0707] Y is a unit including at least one of formulae (2d-1) to (2d-3);

[0708] [Chemical Formula 72]

[0709]

[0710] n is an integer of 0 to 200; m is an integer of 0 to 200; p is an integer of 0 to 10,000; q is an integer of 1 to 100; wherein n+m is not 0, and the bonding order of D1, FAE, AE, and Y is not specific);

[0711] A and B are the same or different, and are an alkyl group which can contain a hydrogen atom, a fluorine atom, and / or a crosslinkable functional group, a phenyl group which can contain a fluorine atom and / or a crosslinkable functional group, a -COOH group, a -OR (R is an alkyl group which can contain a hydrogen atom or a fluorine atom and / or a crosslinkable functional group) group, an ester group, or a carbonate group (wherein the terminal of D is an oxygen atom, it is not a -COOH group, -OR, an ester group, and a carbonate group).

[0712] In the case where the composition of the present application is used as an electrolyte solution, the composition of the present application can 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.

[0713] As the cyclic sulfone, a monosulfone compound, i.e., a trimethylene sulfone, a tetramethylene sulfone, a hexamethylene sulfone, a disulfone compound, i.e., a trimethylene disulfone, a tetramethylene disulfone, a hexamethylene disulfone, and the like can be mentioned. Among them, from the viewpoint of the dielectric constant and viscosity, a tetramethylene sulfone, a tetramethylene disulfone, a hexamethylene sulfone, a hexamethylene disulfone, and particularly a tetramethylene sulfone (a cyclic butane sulfone) is more preferable.

[0714] As the sulfolanes, sulfolane and / or sulfolane derivatives (hereinafter, also including sulfolane, and sometimes simply referred to as "sulfolanes") are preferable. As the sulfolane derivatives, substances in which one or more of the hydrogen atoms bonded to the carbon atoms constituting the sulfolane ring are substituted with fluorine atoms or alkyl groups are preferable.

[0715] Among them, from the viewpoint of high ion conductivity and high input / output, 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, 4-fluoro-2-methylsulfolane, 5-fluoro-3-methylsulfolane, 5-fluoro-2-methylsulfolane, 2-fluoromethylsulfolane, 3-fluoromethylsulfolane, 2-difluoromethylsulfolane, 3-difluoromethylsulfolane, 2-trifluoromethylsulfolane, 3-trifluoromethylsulfolane, 2-fluoro-3-(trifluoromethyl)sulfolane, 3-fluoro-3-(trifluoromethyl)sulfolane, 4-fluoro-3-(trifluoromethyl)sulfolane, 3-cyclobutene sulfolane, 5-fluoro-3-(trifluoromethyl)sulfolane, and the like are preferable.

[0716] In addition, as the chain sulfones, 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 trifluoromethyl sulfone, perfluoroethyl methyl sulfone, ethyl trifluoroethyl sulfone, ethyl pentafluoroethyl sulfone, di(trifluoroethyl) sulfone, perfluoro diethyl 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, pentafluoroethyl n-butyl sulfone, pentafluoroethyl t-butyl sulfone, and the like can be mentioned.

[0717] Among them, in terms of high ion conductivity and high input and output, 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 pentafluoroethyl sulfone, trifluoromethyl n-propyl sulfone, trifluoromethyl isopropyl sulfone, trifluoroethyl n-butyl sulfone, trifluoroethyl t-butyl sulfone, trifluoromethyl n-butyl sulfone, trifluoromethyl t-butyl sulfone, and the like are preferable.

[0718] The content of the sulfone compound is not particularly limited, and is an arbitrary content as long as the effect of the present application is not significantly impaired, and is usually 0.3% by volume or more, preferably 0.5% by volume or more, and more preferably 1% by volume or more, and is usually 40% by volume or less, preferably 35% by volume or less, and more preferably 30% by volume or less, in 100% by volume of the solvent. If the content of the sulfone compound is within the above range, the effect of improving the durability of the cycle characteristics, storage characteristics, and the like is easily obtained, and in addition, the viscosity of the nonaqueous electrolyte solution can be brought within an appropriate range, the decrease in the conductivity can be avoided, and the input and output characteristics and the charge and discharge rate characteristics of the nonaqueous electrolyte secondary battery can be brought within an appropriate range.

[0719] In the case where the composition of the present application is used as an electrolyte, the composition of the present application preferably contains at least one compound (7) selected from the group consisting of lithium fluorophosphates (excluding LiPF6) and lithium salts having an S=O group as an additive from the viewpoint of improving the output characteristics.

[0720] Note that, in the case where the compound (7) is used as an additive, a compound other than the compound (7) is preferably used as the above-mentioned electrolyte salt.

[0721] As the above-mentioned lithium fluorophosphates, lithium monofluorophosphate (LiPO3F), lithium difluorophosphate (LiPO2F2), and the like can be given.

[0722] As the above-mentioned lithium salts having an S=O group, lithium monofluorosulfate (FSO3Li), lithium methylsulfate (CH3OSO3Li), lithium ethylsulfate (C2H5OSO3Li), lithium 2,2,2-trifluoroethylsulfate, and the like can be given.

[0723] As the compound (7), LiPO2F2, FSO3Li, and C2H5OSO3Li are preferable.

[0724] The content of the compound (7) with respect to the electrolyte solution is preferably 0.001 to 20% by mass, more preferably 0.01 to 15% by mass, further preferably 0.1 to 10% by mass, and particularly preferably 0.1 to 7% by mass.

[0725] In the case where the composition of the present application is used as an electrolyte solution, the composition of the present application can be further combined with other additives as needed. As the other additives, for example, metal oxides, glass, and the like can be given.

[0726] In the case where the composition of the present application is used as an electrolyte solution, the composition of the present application preferably contains at least one selected from the group consisting of an unsaturated cyclic carbonate, the compound (4), a nitrile compound, a fluorinated saturated cyclic carbonate, a lithium salt having an S=0 group, a lithium fluorophosphate salt (excluding LiPF6), a lithium sulfamate compound, and a silyl ester compound of phosphoric acid or phosphorous acid as an additive. By containing these additives, the electric resistance of an electrochemical device can be further reduced, and in addition, the cycle characteristics can be further improved.

[0727] The above-mentioned additive is preferably at least one selected from the group consisting of an unsaturated cyclic carbonate, the compound (5), the compound (6), a nitrile compound represented by the general formula (la), a fluorinated saturated cyclic carbonate, a lithium alkyl sulfate compound, a lithium sulfonate compound, lithium difluorophosphate (LiPO2F2), a lithium sulfamate compound represented by the following general formula (11), and a silyl ester compound of phosphoric acid or phosphorous acid represented by the general formula (M) 301 (OSiR 301 3)3(M 301 is P or P=0, R 301 is independently an alkyl group having 1 to 4 carbon atoms, and

[0728] Further preferably, it is at least one selected from the group consisting of vinylene carbonate, vinyl ethylene carbonate, succinic anhydride, maleic anhydride, adiponitrile, fluorinated ethylene carbonate, difluorinated ethylene carbonate, C2H5OSO3Li, FSO3Li, LiPO2F2, (CH3CH2)2NSO3Li, (CF3CH2)2NSO3Li, (CF3CH2)(CH3)NSO3Li, (CNCH2)2NSO3Li, tris(trimethylsilyl) phosphate, tris(triethylsilyl) phosphate, tris(tert-butyldimethylsilyl) phosphate, tris(trimethylsilyl) phosphite, tris(triethylsilyl) phosphite, and tris(tert-butyldimethylsilyl) phosphite.

[0729] As the additive, particularly preferably, it is a lithium sulfamate compound represented by the following general formula (11).

[0730] The content of the additive relative to the electrolyte is preferably 0.001 to 5.0% by mass. More preferably, it is 0.01% by mass or more, even more preferably 0.1% by mass or more, particularly preferably 0.5% by mass or more, further preferably 3.0% by mass or less, even more preferably 2.0% by mass or less, and particularly preferably 1.5% by mass or less.

[0731] General formula (11):

[0732] [Chemistry 73]

[0733]

[0734] (In general formula (11), R) 111 and R 112 Each independently is:

[0735] -H、

[0736] -F、

[0737] Formula: -O p101 -(SiR 113 2O) n101 -SiR 114 3(R 113 and R 114 Each of the following groups is independently an alkyl group in which one or more hydrogen atoms can be replaced by fluorine atoms, an alkenyl group in which one or more hydrogen atoms can be replaced by fluorine atoms, an alkynyl group in which one or more hydrogen atoms can be replaced by fluorine atoms, or an aryl group in which one or more hydrogen atoms can be replaced by fluorine atoms, where n101 is an integer greater than or equal to 0, and p101 is 0 or 1.

[0738] Alkyl groups with 1 to 7 carbon atoms

[0739] alkenyl groups with 2 to 7 carbon atoms

[0740] Alkynes with 2 to 7 carbon atoms

[0741] Aryl groups with 6 to 15 carbon atoms

[0742] -SO2X 101 (X 101 Alkyl groups in which -H, -F, or one or more hydrogen atoms can be replaced by fluorine atoms.

[0743] -SO3X 102 (X 102 Alkyl groups consisting of -H, -F, or one or more hydrogen atoms that can be replaced by fluorine atoms.

[0744] R 111 With R 112a substituted or unsubstituted hydrocarbon group having 1 to 30 carbon atoms,

[0745] The above substituent can include one or more heteroatoms having a valence of 2 to 6 in its structure, and one or more hydrogen atoms can be substituted with a fluorine atom or a functional group having 0 to 7 carbon atoms.

[0746] Further, in the case where the composition of the present application is used as an electrolyte solution, the composition of the present application preferably contains at least one selected from the group consisting of an unsaturated cyclic carbonate, compound (4), a nitrile compound, a fluorinated saturated cyclic carbonate, an anion having an S=O group, a fluorophosphoric acid anion (wherein PF6 - except for), an aminosulfonic acid anion, and a silyl ester compound of phosphoric acid or phosphorous acid, as an additive. By containing these additives, the electric resistance of an electrochemical device can be further reduced, and further, the cycle characteristics can be further improved.

[0747] The above additive is preferably at least one selected from the group consisting of an unsaturated cyclic carbonate, compound (5), compound (6), a nitrile compound represented by general formula (1a), a fluorinated saturated cyclic carbonate, an alkylsulfate anion, a sulfonic acid anion, a difluorophosphoric acid anion (PO2F2 - ), an aminosulfonic acid anion represented by the following general formula (11-1), and a silyl ester compound of phosphoric acid or phosphorous acid represented by general formula (11-2), 301 (OSiR 301 3)3(M 301 is P or P=O, R 301 independently is an alkyl group having 1 to 4 carbon atoms, and

[0748] Further preferably, it is at least one selected from the group consisting of vinylene carbonate, vinyl ethylene carbonate, succinic anhydride, maleic anhydride, adiponitrile, fluorinated ethylene carbonate, difluorinated ethylene carbonate, C2H5OSO3 - , FSO3 - , PO2F2 - , (CH3CH2)2NSO3 - , (CF3CH2)2NSO3 - , (CF3CH2)(CH3)NSO3 - , (CNCH2)2NSO3 - , phosphoric acid tris(trimethylsilyl) ester, phosphoric acid tris(triethylsilyl) ester, phosphoric acid tris(tert-butyldimethylsilyl) ester, phosphorous acid tris(trimethylsilyl) ester, phosphorous acid tris(triethylsilyl) ester, and phosphorous acid tris(tert-butyldimethylsilyl) ester.

[0749] As the additive, an aminosulfonic acid anion represented by the following general formula (11-1) is particularly preferable.

[0750] The content of the additive is preferably 0.001 to 5.0% by mass with respect to the electrolyte. More preferably, it is 0.01% by mass or more, further preferably 0.1% by mass or more, particularly preferably 0.5% by mass or more, and more preferably, it is 3.0% by mass or less, further preferably 2.0% by mass or less, and particularly preferably 1.5% by mass or less.

[0751] General formula (11-1):

[0752] [Chemical Formula 74]

[0753]

[0754] (In general formula (11-1), R 111 and R 112 each independently is:

[0755] -H,

[0756] -F,

[0757] -O, p101 -SiR 113 2O) n101 -SiR 114 3(R 113 and R 114 each independently is one or more alkyl groups in which one or more hydrogen atoms can be replaced with a fluorine atom, one or more alkenyl groups in which one or more hydrogen atoms can be replaced with a fluorine atom, one or more alkynyl groups in which one or more hydrogen atoms can be replaced with a fluorine atom, or one or more aryl groups in which one or more hydrogen atoms can be replaced with a fluorine atom, n101 is an integer of 0 or more, and p101 is 0 or 1.

[0758] an alkyl group having 1 to 7 carbon atoms,

[0759] an alkenyl group having 2 to 7 carbon atoms,

[0760] an alkynyl group having 2 to 7 carbon atoms,

[0761] an aryl group having 6 to 15 carbon atoms,

[0762] -SO2X 101 (X 101 is -H, -F, or an alkyl group in which one or more hydrogen atoms can be replaced with a fluorine atom.),

[0763] -SO3X 102 (X 102 is -H, -F, or an alkyl group in which one or more hydrogen atoms can be replaced with a fluorine atom.), or

[0764] R 111 R 112 a substituted group of a hydrocarbon group having 2 to 7 carbon atoms which forms a ring structure in combination with R

[0765] The above-mentioned substituted group can contain one or more heteroatoms having a valence of 2 to 6 in its structure, and one or more hydrogen atoms can be substituted with a fluorine atom or a functional group having 0 to 7 carbon atoms.

[0766] Hereinafter, the lithium sulfamate compound represented by General Formula (11) (Compound (11)) and the sulfamate anion represented by General Formula (11-1) (Anion (11-1)) will be described.

[0767] The compound (11) is represented by General Formula (11):

[0768] [Chemical Formula 75]

[0769]

[0770] In General Formula (11), R 111 and R 112 are each independently:

[0771] -H,

[0772] -F,

[0773] -O, p101 -SiR 113 2O, n101 -SiR 114 3(R 113 and R 114 are each independently an alkyl group in which one or more hydrogen atoms can be replaced with a fluorine atom, an alkenyl group in which one or more hydrogen atoms can be replaced with a fluorine atom, an alkynyl group in which one or more hydrogen atoms can be replaced with a fluorine atom, or an aryl group in which one or more hydrogen atoms can be replaced with a fluorine atom, n101 is an integer of 0 or more, and p101 is 0 or 1.

[0774] an alkyl group having 1 to 7 carbon atoms,

[0775] an alkenyl group having 2 to 7 carbon atoms,

[0776] an alkynyl group having 2 to 7 carbon atoms,

[0777] an aryl group having 6 to 15 carbon atoms,

[0778] -SO2X 101 (X 101 is -H, -F, or an alkyl group in which one or more hydrogen atoms can be replaced with a fluorine atom.

[0779] -SO3X 102 (X 102 -H, -F, or an alkyl group in which one or more hydrogen atoms can be replaced with a fluorine atom, an alkyl group having 1 to 7 carbon atoms in which one or more hydrogen atoms can be replaced with a fluorine atom, a saturated heterocyclic group having 1 to 7 carbon atoms, or an alkoxy group having 1 to 7 carbon atoms. X

[0780] R 111 -H, -F, or an alkyl group in which one or more hydrogen atoms can be replaced with a fluorine atom, an alkyl group having 1 to 7 carbon atoms in which one or more hydrogen atoms can be replaced with a fluorine atom, a saturated heterocyclic group having 1 to 7 carbon atoms, or an alkoxy group having 1 to 7 carbon atoms. X 112 -H, -F, or an alkyl group in which one or more hydrogen atoms can be replaced with a fluorine atom, an alkyl group having 1 to 7 carbon atoms in which one or more hydrogen atoms can be replaced with a fluorine atom, a saturated heterocyclic group having 1 to 7 carbon atoms, or an alkoxy group having 1 to 7 carbon atoms. X

[0781] The above substituents can include one or more heteroatoms having a valence of 2 to 6 in their structures, and one or more hydrogen atoms can be replaced with a fluorine atom or a functional group having 0 to 7 carbon atoms.

[0782] Note that the number of carbon atoms of each of the above substituents refers to the number of carbon atoms including the number of carbon atoms of the functional group.

[0783] The above substituents represent -H, -F, the above formula: -O p101 -(SiR 113 2O) n101 -SiR 114 3, the above alkyl group, the above alkenyl group, the above alkynyl group, the above aryl group, the above -SO2X 101 , the above -SO3X 102 , or the above hydrocarbon group.

[0784] The above substituents can include one or more heteroatoms having a valence of 2 to 6 in their structures, and one or more hydrogen atoms can be replaced with a fluorine atom or a functional group having 0 to 7 carbon atoms.

[0785] As the functional group that the above substituents can have, for example, a phenyl group, an anisyl group, a benzyl group, a cyano group, a trialkylsilyl group (preferably, the number of carbon atoms of the alkyl group is 1 to 4), -SO2X 103 (X 103 -H, -F, or an alkyl group in which one or more hydrogen atoms can be replaced with a fluorine atom, an alkyl group having 1 to 7 carbon atoms in which one or more hydrogen atoms can be replaced with a fluorine atom, a saturated heterocyclic group having 1 to 7 carbon atoms, or an alkoxy group having 1 to 7 carbon atoms. X 103 The number of carbon atoms of the alkyl group in the above X

[0786] In the above R 111 and R 112 , the alkyl group can be linear, branched, or cyclic, and the number of carbon atoms is preferably 1 to 10, more preferably 1 to 7. The alkyl group can be a fluoroalkyl group in which a hydrogen atom bonded to carbon is replaced with a fluorine atom, or a group in which a hydrogen atom bonded to carbon is replaced with the above functional group.

[0787] In the above R 111 and R 112 , the alkenyl group can be linear, branched, or cyclic, and the number of carbon atoms is preferably from 2 to 10, more preferably from 2 to 7. The alkenyl group can be a fluoroalkenyl group in which a hydrogen atom bonded to carbon is replaced with a fluorine atom, or a group in which a hydrogen atom bonded to carbon is replaced with the above functional group.

[0788] In the above R 111 and R 112 , the alkynyl group can be linear, branched, or cyclic, and the number of carbon atoms is preferably from 2 to 10, more preferably from 2 to 7. The alkynyl group can be a fluoroalkynyl group in which a hydrogen atom bonded to carbon is replaced with a fluorine atom, or a group in which a hydrogen atom bonded to carbon is replaced with the above functional group.

[0789] In the above R 111 and R 112 , the aryl group preferably has from 6 to 7 carbon atoms. The aryl group can be a fluoroaryl group in which a hydrogen atom bonded to carbon is replaced with a fluorine atom, or a group in which a hydrogen atom bonded to carbon is replaced with the above functional group.

[0790] The above R 111 and R 112 may be a group represented by the formula: -O p101 -(SiR 113 2O) n101 -SiR 114 3(R 113 and R 114 are each independently an alkyl group in which one or more hydrogen atoms can be replaced with a fluorine atom, an alkenyl group in which one or more hydrogen atoms can be replaced with a fluorine atom, an alkynyl group in which one or more hydrogen atoms can be replaced with a fluorine atom, or an aryl group in which one or more hydrogen atoms can be replaced with a fluorine atom, n101 is an integer of 0 or more, and p101 is 0 or 1.

[0791] In the above R 113 and R 114 , the alkyl group in which one or more hydrogen atoms can be replaced with a fluorine atom preferably has from 1 to 10 carbon atoms, more preferably from 1 to 7.

[0792] The alkenyl group and the alkynyl group in which one or more hydrogen atoms can be replaced with a fluorine atom preferably have from 2 to 10 carbon atoms, more preferably from 2 to 7.

[0793] The aryl group in which one or more hydrogen atoms can be replaced with a fluorine atom preferably has from 6 to 8 carbon atoms, more preferably from 6 to 7.

[0794] In the above formula, n101 is an integer of 0 or more, preferably 2000 or less, more preferably an integer of 0 to 100, and further preferably 0 to 10.

[0795] R 111 R 112 may be -SO2X 101 (X 101 -H, -F, or an alkyl group in which one or more hydrogen atoms can be replaced with a fluorine atom). The number of carbon atoms in the alkyl group in the above -SO2X 101 group is preferably from 1 to 10, more preferably from 1 to 7.

[0796] R 111 R 112 may be -SO3X 102 (X 102 -H, -F, or an alkyl group in which one or more hydrogen atoms can be replaced with a fluorine atom). The number of carbon atoms in the alkyl group in the above -SO3X 102 group is preferably from 1 to 10, more preferably from 1 to 7.

[0797] As the above R101and R102, specific examples include: chain alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl, pentyl, isopentyl, neopentyl, sec-pentyl, 3-pentyl, t-pentyl, and hexyl; cyclic alkyl groups such as cyclopentyl, cyclohexyl, norbornyl, and 1-adamantyl; alkenyl groups such as ethenyl, 1-propenyl, 2-propenyl (allyl), 2-butenyl, and 1,3-butadienyl; alkynyl groups such as ethynyl, 1-propynyl, 2-propynyl, and 2-butynyl; halogenated alkyl groups such as trifluoromethyl, 2,2,2-trifluoroethyl, 1,1,2,2-tetrafluoroethyl, pentafluoroethyl, 2,2,3,3,3-pentafluoropropyl, 1,1,2,3,3,3-hexafluoropropyl, and heptafluoropropyl; halogenated alkenyl groups such as 1-fluoroethenyl and 2-fluoroallyl; alkyl groups having a functional group such as cyanomethyl; alkyl groups having a saturated heterocyclic group such as 3-pyrrolidinylpropyl; aryl groups which can have an alkyl substituent, an alkoxy substituent, or the like, such as phenyl; aralkyl groups such as phenylmethyl and phenylethyl; trialkylsilyl groups such as trimethylsilyl; trialkylsiloxy groups such as trimethylsiloxy; sulfonyl groups such as fluorosulfonyl, trifluoromethylsulfonyl, and pentafluoroethylsulfonyl; and the like, but are not limited thereto.

[0798] In addition, in the case where the above hydrocarbon group is bonded to R 111 and R 112 to form a cyclic structure, for example, the nitrogen atom (N) in general formula (2) and R 111 and R 112 may form a cyclic amino group such as pyrrolidinyl, piperidinyl, or the like, or a heteroatom-containing cyclic amino group such as 4-morpholinyl, succinimidyl, maleimidyl, or the like. They can be a group in which one or more hydrogen atoms bonded to carbon can be replaced with a fluorine atom, or a group in which a hydrogen atom bonded to carbon can be replaced with the above functional group. In addition, the cyclic structure can also contain a double bond or a triple bond.

[0799] The substituent can contain a hetero atom of valence 2 to 6. As the hetero atom, an oxygen atom (O), a sulfur atom (S), a nitrogen atom (N), a silicon atom (Si), a phosphorus atom (P), a boron atom (B), or the like can be given. More preferably, an oxygen atom, a sulfur atom, or a nitrogen atom is given.

[0800] R 111 and R 112 Preferably, the alkyl group is an alkyl group having 1 to 7 carbon atoms, more preferably an alkyl group having 1 to 5 carbon atoms, and further preferably an alkyl group having 1 to 4 carbon atoms.

[0801] These alkyl groups can contain one or more hetero atoms of valence 2 to 6 in the structure, and one or more hydrogen atoms can be substituted with a fluorine atom or a functional group having 0 to 6 (preferably 0 to 4, and more preferably 0 to 3) carbon atoms.

[0802] As the hetero atom, an oxygen atom, a sulfur atom, or a nitrogen atom is preferred, an oxygen atom or a nitrogen atom is more preferred, and a nitrogen atom is further preferred.

[0803] The alkyl group can contain an ether bond (-O-).

[0804] As the functional group, a cyano group is preferred.

[0805] As the compound (11), for example, a compound represented by the following formula can be given.

[0806] [Chem. 76]

[0807]

[0808] [Chem. 77]

[0809]

[0810] [Chem. 78]

[0811]

[0812] [Chem. 79]

[0813]

[0814] [Chem. 80]

[0815]

[0816] [Chem. 81]

[0817]

[0818] [Chem. 82]

[0819]

[0820] [Chemical Formula 83]

[0821]

[0822] [Chemical Formula 84]

[0823]

[0824] [Chemical Formula 85]

[0825]

[0826] Note that in the present specification, Me represents a methyl group, Et represents an ethyl group, n-Pr represents a normal propyl group, i-Pr represents an isopropyl group, n-Bu represents a normal butyl group, i-Bu represents an isobutyl group, s-Bu represents a sec-butyl group, t-Bu represents a tert-butyl group, TMS represents a trimethylsilyl group, and TBDMS represents a tert-butyldimethylsilyl group. Furthermore, in the case where the following is described, an R bond can be bonded to any carbon atom constituting a benzene ring, for example, at any of the ortho, meta, and para positions.

[0827] [Chemical Formula 86]

[0828]

[0829] Note that the exemplification of the compounds in the present specification is set to also include geometric isomers of the compounds (if present), and is not limited to the specific examples described.

[0830] As the compound (11), a compound represented by the following formula is preferable.

[0831] [Chemical Formula 87]

[0832]

[0833] As the compound (11), a compound represented by the following formula is more preferable.

[0834] [Chemical Formula 11]

[0835]

[0836] As the compound (11), a compound represented by the following formula is further preferable.

[0837] [Chemical Formula 89]

[0838]

[0839] The compound (11) can be a compound represented by the following general formula (11a) (hereinafter also referred to as compound (11a)).

[0840] General Formula (11a):

[0841] [Chemical Formula 90]

[0842]

[0843] (In the formula, R 201 and R 202 each independently is:

[0844] -H,

[0845] -F,

[0846] Formula: -O p101 -(SiR 113 2O) n101 -SiR 114 3(R 113 and R 114 each independently is one or more alkyl groups in which one or more hydrogen atoms can be replaced with a fluorine atom, one or more alkenyl groups in which one or more hydrogen atoms can be replaced with a fluorine atom, one or more alkynyl groups in which one or more hydrogen atoms can be replaced with a fluorine atom, or one or more aryl groups in which one or more hydrogen atoms can be replaced with a fluorine atom, n101 is an integer of 0 or more, and p101 is 0 or 1.

[0847] alkyl groups having 1 to 7 carbon atoms,

[0848] alkenyl groups having 2 to 7 carbon atoms,

[0849] alkynyl groups having 2 to 7 carbon atoms,

[0850] aryl groups having 6 to 15 carbon atoms,

[0851] -SO2X 101 (X 101 is -H, -F, or an alkyl group in which one or more hydrogen atoms can be replaced with a fluorine atom.), or

[0852] -SO3X 102 (X 102 is -H, -F, or an alkyl group in which one or more hydrogen atoms can be replaced with a fluorine atom).

[0853] The above substituents can include one or more heteroatoms having a valence of 2 to 6 in their structures, and one or more hydrogen atoms can be replaced with a fluorine atom or a functional group having 0 to 7 carbon atoms.

[0854] wherein at least one of R 201 and R 202 is -F.

[0855] In General Formula (11a), R 201and R 202 At least one of them needs to be -F.

[0856] R in general formula (11a) 201 and R 202 The above-mentioned -O p101 -(SiR 113 2O) n101 -SiR 114 3. The above-mentioned alkyl, alkenyl, alkynyl, aryl, and -SO2X groups 101 And the above-mentioned -SO3X 102 Examples of R in general formula (11) can be cited. 111 and R 112 Same group.

[0857] As a compound (11a), for example, compounds represented by the following formula can be exemplified.

[0858] [Chemistry 91]

[0859]

[0860] As compound (11a), the following compounds are preferred:

[0861]

[0862] Compound (11) can be manufactured, for example, by the manufacturing method described in International Publication No. 2019 / 188207.

[0863] The anion (11-1) is represented by the general formula (11-1):

[0864] [Chemistry 93]

[0865]

[0866] In general formula (11-1), R 111 and R 112 Each independently is:

[0867] -H、

[0868] -F、

[0869] Formula: -O p101 -(SiR 113 2O) n101 -SiR 114 3(R 113 and R 114one or more hydrogen atoms of an alkyl group, one or more hydrogen atoms of an alkenyl group, one or more hydrogen atoms of an alkynyl group, or one or more hydrogen atoms of an aryl group can be replaced with a fluorine atom, n101 is an integer of 0 or more, and p101 is 0 or 1.

[0870] an alkyl group having 1 to 7 carbon atoms,

[0871] an alkenyl group having 2 to 7 carbon atoms,

[0872] an alkynyl group having 2 to 7 carbon atoms,

[0873] an aryl group having 6 to 15 carbon atoms,

[0874] -SO2X 101 (X 101 -H, -F, or an alkyl group in which one or more hydrogen atoms can be replaced with a fluorine atom.

[0875] -SO3X 102 (X 102 -H, -F, or an alkyl group in which one or more hydrogen atoms can be replaced with a fluorine atom.

[0876] R 111 forms a cyclic structure in combination with R 112 having 2 to 7 carbon atoms, which can include a multiple bond in the cyclic structure,

[0877] one or more 2- to 6-valent heteroatoms can be included in the structure of the above substituent, and one or more hydrogen atoms can be replaced with a fluorine atom or a functional group having 0 to 7 carbon atoms.

[0878] As R 111 and R 112 in General Formula (11-1), the same groups as those described with respect to General Formula (11) can be given, and the preferable examples are also the same.

[0879] As a specific example of the anion (11-1), an anion having a structure in which a lithium ion (Li + ) is removed from the compounds exemplified as the compound (11) can be given.

[0880] As the anion (11-1), an anion represented by the following formula is preferable.

[0881] [Chem. 94]

[0882]

[0883] As the anion (11-1), an anion represented by the following formula is more preferable.

[0884] [Chemical Formula 95]

[0885]

[0886] As the anion (11-1), further preferably an anion represented by the following formula is used.

[0887] [Chemical Formula 96]

[0888]

[0889] In the case where the composition of the present application is used as an electrolyte solution, the composition of the present application preferably contains hydrogen fluoride (HF) in an amount of 1 to 1000 ppm. By containing HF, the film formation of the above-mentioned additive is promoted. If the amount of HF is too small, the film formation ability on the negative electrode is reduced, and there is a tendency that the characteristics of the electrochemical device are reduced. Further, if the amount of HF is too large, there is a tendency that the oxidation resistance of the electrolyte solution is reduced due to the influence of HF. The composition of the present application does not reduce the high-temperature storage capacity recovery rate of the electrochemical device even if it contains HF in the above-mentioned range.

[0890] The amount of HF is more preferably 5 ppm or more, further preferably 10 ppm or more, and particularly preferably 20 ppm or more. In addition, the amount of HF is more preferably 200 ppm or less, further preferably 100 ppm or less, more further preferably 80 ppm or less, and particularly preferably 50 ppm or less.

[0891] The amount of HF can be measured by a neutralization titration method.

[0892] In the case where the composition of the present application is used as an electrolyte solution, the composition of the present application can be produced by any method using the above-mentioned components.

[0893] In the case where the composition of the present application is used as an electrolyte solution, the composition of the present application can be appropriately applied to, for example, a lithium ion secondary battery, a lithium ion capacitor, a hybrid capacitor, an electric double layer capacitor, and the like. Hereinafter, a non-aqueous electrolyte battery having the composition of the present application as an electrolyte solution will be described.

[0894] The above-mentioned non-aqueous electrolyte battery can adopt a publicly known structure, and typically has a positive electrode and a negative electrode that can absorb and release ions (for example, lithium ions) and an electrolyte solution that is the above-mentioned composition of the present application. An electrochemical device having such a composition of the present application is also one embodiment of the present application.

[0895] As the electrochemical device, there can be mentioned lithium ion secondary batteries, lithium ion capacitors, capacitors (hybrid capacitors, electric double layer capacitors), radical batteries, solar cells (particularly, dye-sensitized solar cells), lithium ion primary batteries, fuel cells, various electrochemical sensors, electrochromic elements, electrochemical switching elements, aluminum electrolytic capacitors, tantalum electrolytic capacitors, and the like, and preferably, lithium ion secondary batteries, lithium ion capacitors, and electric double layer capacitors.

[0896] A component provided with the above electrochemical device is also one embodiment of the present application.

[0897] The present application also relates to a lithium ion secondary battery provided with the composition of the present application as an electrolyte solution.

[0898] The above lithium ion secondary battery is preferably provided with a positive electrode, a negative electrode, and the above electrolyte solution.

[0899] <Positive Electrode>

[0900] The positive electrode is composed of a positive electrode active material layer containing a positive electrode active material, and a current collector.

[0901] As the positive electrode active material, any material that can electrochemically absorb and release lithium ions can be used without particular limitation, and for example, there can be mentioned lithium-containing transition metal complex oxides, lithium-containing transition metal phosphoric acid compounds, sulfur-based materials, and electrically conductive polymers. Among them, as the positive electrode active material, lithium-containing transition metal complex oxides and lithium-containing transition metal phosphoric acid compounds are preferred, and lithium-containing transition metal complex oxides that produce high voltage are particularly preferred.

[0902] As the transition metal of the lithium-containing transition metal complex oxide, V, Ti, Cr, Mn, Fe, Co, Ni, Cu, and the like are preferred, and as specific examples, there can be mentioned lithium-cobalt complex oxides such as LiCoO2, lithium-nickel complex oxides such as LiNiO2, lithium-manganese complex oxides such as LiMnO2, LiMn2O4, Li2MnO4, and the like, and transition metals in which a part of the transition metal atoms that are the main body of the lithium transition metal complex oxide are substituted with other elements such as Na, K, B, F, Al, Ti, V, Cr, Mn, Fe, Co, Li, Ni, Cu, Zn, Mg, Ga, Zr, Si, Nb, Mo, Sn, W, and the like. As specific examples of the substituted materials, there can be mentioned LiNi 0.5 Mn 0.5 O2, LiNi 0.85 Co 0.10 Al 0.05 O2, LiNi 0.5 Co 0.2 Mn 0.3 O2, LiNi 0.6 Co 0.2Mn 0.2 O2, LiNi 0.33 Co 0.33 Mn 0.33 O2, LiNi 0.8 Co 0.1 Mn 0.1 O2, LiNi 0.45 Co 0.10 Al 0.45 O2, LiMn 1.8 Al 0.2 O4, LiMn 1.5 Ni 0.5 O4, etc.

[0903] Among them, as the above-mentioned lithium-containing transition metal complex oxide, LiMn 1.5 Ni 0.5 O4, LiNi 0.5 Co 0.2 Mn 0.3 O2, LiNi 0.6 Co 0.2 Mn 0.2 O2. Among them, in the case of a high voltage of 4.4 V or more, LiMn 1.5 Ni 0.5 O4.

[0904] Further, among them, as the above-mentioned lithium-containing transition metal complex oxide, from the viewpoint of being able to provide a lithium ion secondary battery with a high capacity, LiNi 0.6 Co 0.2 Mn 0.2 O2, LiNi 0.8 Co 0.1 Mn 0.1 O2, LiNi 0.85 Co 0.10 Al 0.05 O2.

[0905] As the transition metal of the lithium-containing transition metal phosphate compound, V, Ti, Cr, Mn, Fe, Co, Ni, Cu, etc. are preferable, and as specific examples, for example, lithium iron phosphate (lithium iron phosphate) such as LiFePO4, Li3Fe2(PO4)3, LiFeP2O7, cobalt phosphate such as LiCoPO4, and the like can be given; a substance in which a part of the transition metal atoms as the main body of these lithium transition metal phosphate compounds is substituted with other metals such as Al, Ti, V, Cr, Mn, Fe, Co, Li, Ni, Cu, Zn, Mg, Ga, Zr, Nb, Si, etc.

[0906] As the above-mentioned lithium-containing transition metal complex oxide, for example,

[0907] Li a Mn 2-b M 1 b O4(0.9≤a; 0≤b≤1.5; M 1 Li-Mn spinel composite oxide represented by Li

[0908] LiNi 1-c M 2 c O2(0≤c≤0.5; M 2 Li-Ni composite oxide represented by Li

[0909] LiCo 1-d M 3 d O2(0≤d≤0.5; M 3 Li-Ni composite oxide represented by Li

[0910] LiCoO2, LiMnO2, LiNiO2, LiMn2O4, LiNi 0.8 Co 0.15 Al 0.05 O2, or LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2.

[0911] LiFePO4, LiNi 0.8 Co 0.2 O2, Li 1.2 Fe 0.4 Mn 0.4 O2, LiNi 0.5 Mn 0.5 O2, LiV3O6, Li2MnO3, etc.

[0912] As the above-mentioned sulfur-based material, a material containing a sulfur atom can be exemplified, and it is preferable to be at least one selected from the group consisting of elemental sulfur, a metal sulfide, and an organic sulfur compound, and more preferable to be elemental sulfur. The above-mentioned metal sulfide can be a metal polysulfide. The above-mentioned organic sulfur compound can be an organic polysulfide.

[0913] As the above-mentioned metal sulfide, a compound represented by LiS x (0 < x < 8); a compound represented by Li2S x (0 < x < 8); a compound having a two-dimensional layered structure such as TiS2or MoS2; a compound having a three-dimensional framework structure such as a Scheelite phase compound represented by a general formula Me x Mo6S8(Me is various transition metals represented by Pb, Ag, Cu), and the like.

[0914] As the above-mentioned organic sulfur compound, a carbon sulfide compound and the like can be exemplified.

[0915] The above-mentioned organic sulfur compound is sometimes supported on a material having a small pore such as carbon and used as a carbon composite material. As the content of sulfur contained in the carbon composite material, from the viewpoint that the cycle performance is further excellent and the overvoltage is further reduced, it is preferable to be 10 to 99 mass%, more preferable to be 20 mass% or more, further preferable to be 30 mass% or more, particularly preferable to be 40 mass% or more, and it is preferable to be 85 mass% or less.

[0916] In a case where the above-mentioned positive electrode active material is the above-mentioned elemental sulfur, the content of sulfur contained in the above-mentioned positive electrode active material is equal to the content of the above-mentioned elemental sulfur.

[0917] As the conductive polymer, a p-doped conductive polymer, an n-doped conductive polymer, and the like can be exemplified. As the conductive polymer, a polyacetylene-based compound, a polyaniline-based compound, a heterocyclic polymer, an ionic polymer, a ladder-type polymer, a network-type polymer, and the like can be exemplified.

[0918] Further, if lithium phosphate is contained in the positive electrode active material, the continuous charge characteristics are improved, and thus it is preferable. The use of lithium phosphate is not limited, and it is preferable to mix the above-mentioned positive electrode active material and lithium phosphate. As the amount of the used lithium phosphate, the lower limit is preferably 0.1 mass% or more, more preferably 0.3 mass% or more, and further preferably 0.5 mass% or more, and the upper limit is preferably 10 mass% or less, more preferably 8 mass% or less, and further preferably 5 mass% or less, with respect to the total of the above-mentioned positive electrode active material and lithium phosphate.

[0919] Further, a substance obtained by adhering a substance having a different composition from that of the positive electrode active material to the surface of the positive electrode active material can be used. As the surface adhering substance, oxides such as alumina, silica, titania, zirconia, magnesia, calcia, boria, antimony oxide, bismuth oxide, lithium sulfate, sodium sulfate, potassium sulfate, magnesium sulfate, calcium sulfate, aluminum sulfate, carbonates such as lithium carbonate, calcium carbonate, magnesium carbonate, and carbon can be given.

[0920] These surface adhering substances can be adhered to the surface of the positive electrode active material by, for example, a method in which the surface adhering substance is impregnated by dissolving or suspending in a solvent and added to the positive electrode active material and dried, a method in which a surface adhering substance precursor is impregnated by dissolving or suspending in a solvent and added to the positive electrode active material and then reacted by heating or the like, a method in which the surface adhering substance is added to the positive electrode active material precursor and simultaneously calcined, and the like. Note that, in the case of adhering carbon, a method in which carbon is mechanically adhered in the form of, for example, activated carbon or the like can also be used.

[0921] As the amount of the surface adhering substance, in the case of the positive electrode active material, 0.1 ppm or more is preferably used as the lower limit, 1 ppm or more is more preferably used, and 10 ppm or more is further preferably used; and 20% or less is preferably used as the upper limit, 10% or less is more preferably used, and 5% or less is further preferably used. By the surface adhering substance, the oxidation reaction of the electrolyte solution at the surface of the positive electrode active material can be suppressed, and the battery life can be improved, but in the case where the amount of the adhering substance is too small, the effect thereof cannot be sufficiently exhibited, and in the case where it is too much, the lithium ion transfer is hindered, and thus the resistance can increase.

[0922] The shape of the particles of the positive electrode active material can be given as a block shape, a polyhedral shape, a spherical shape, an ellipsoidal shape, a plate shape, a needle shape, a columnar shape, and the like that have been conventionally used. Further, the primary particles can be agglomerated to form secondary particles.

[0923] The tap density of the positive electrode active material is generally 1.5 g / cm 3 The above is preferably 2.0 g / cm 3 The above is more preferably 2.5 g / cm 3 The above is most preferably 3.0 g / cm 3 If the tap density of the positive electrode active material is lower than the above lower limit, the amount of the dispersion medium required increases at the time of forming the positive electrode active material layer, and the amount of the conductive material and the binder required increases, the filling rate of the positive electrode active material to the positive electrode active material layer is restricted, and sometimes the battery capacity is restricted. By using a metal complex oxide powder having a high tap density, a positive electrode active material layer having a high density can be formed. The tap density is generally more preferably greater, and there is no particular upper limit, and is generally 4.5 g / cm 3 The above is preferably 4.3 g / cm 3The following.

[0924] Note that in the present application, the tap density is obtained in the following manner: 5 to 10 g of the positive electrode active material powder is put into a 10-ml glass measuring cylinder, and the powder filling density (tap density) g / cm3is measured at a stroke of about 20 mm for 200 times. 3 .

[0925] The median diameter d50 of the positive electrode active material particles (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, further preferably 0.8 μm or more, and most preferably 1.0 μm or more, and is preferably 30 μm or less, more preferably 27 μm or less, further preferably 25 μm or less, and most preferably 22 μm or less. If it is lower than the lower limit described above, a high tap density product cannot sometimes be obtained, and if it is greater than the upper limit, diffusion of lithium within the particles takes time, and thus a decrease in battery performance sometimes occurs, or problems such as streaks occur when the positive electrode of the battery is produced, that is, when the active material is slurried with a conductive material or a binder or the like in a solvent and coated in a thin film shape. Here, the filling property at the time of producing the positive electrode can be further improved by mixing two or more of the positive electrode active materials having different median diameters d50.

[0926] Note that in the present application, the median diameter d50 is measured using a publicly known laser diffraction / scattering type particle size distribution measuring device. When LA-920 manufactured by HORIBA Ltd. is used as the particle size distribution meter, 0.1 mass% of an aqueous sodium hexametaphosphate solution is used as the dispersion medium used at the time of measurement, and after 5 minutes of ultrasonic dispersion, the measurement refractive index is set to 1.24 and measurement is performed.

[0927] In the case where 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, further preferably 0.2 μm or more, and the upper limit is preferably 5 μm or less, more preferably 4 μm or less, further preferably 3 μm or less, and most preferably 2 μm or less. If it exceeds the upper limit described above, it is difficult to form spherical secondary particles, and the powder filling property is sometimes adversely affected, or the specific surface area is greatly reduced, and thus the possibility of a decrease in battery performance such as output characteristics increases. On the contrary, if it is lower than the lower limit described above, the crystal is not usually developed, and thus problems such as poor reversibility of charge and discharge sometimes occur.

[0928] Note that, in the present application, the primary particle diameter is measured by observation using a scanning electron microscope (SEM). Specifically, in a photograph at a magnification of 10,000 times, for any 50 primary particles, the longest value of a slice based on the dividing line between the left and right of the primary particles with respect to a straight line in the horizontal direction is found, and the average value is found by taking the average.

[0929] The BET specific surface area of the positive electrode active material is preferably 0.01 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 / g or less, more preferably 40 m 2 / g or less, further preferably 30 m 2 / g or less. If the BET specific surface area is less than this range, the battery performance tends to decrease, and if it is greater than this range, the tap density is difficult to increase, and sometimes the coatability at the time of formation of the positive electrode active material layer tends to be problematic.

[0930] Further, in the present application, the BET specific surface area is defined as a value measured by the following method: using a surface area meter (for example, a full-automatic surface area measuring device manufactured by Ohkura Riken Co., Ltd.), after pre-drying the sample at 150°C for 30 minutes under nitrogen flow, using nitrogen-helium mixed gas in which the relative pressure value of nitrogen with respect to atmospheric pressure is accurately adjusted to 0.3, measurement is performed using the nitrogen adsorption BET 1-point method based on the gas flow method.

[0931] In the case where the lithium ion secondary battery of the present application is used as a large-sized lithium ion secondary battery for a hybrid automobile or a distributed power source, since high output is required, it is preferable that the particles of the above-described positive electrode active material be mainly secondary particles.

[0932] The particles of the above-described positive electrode active material preferably contain 0.5 to 7.0% by volume of fine particles having an average particle diameter of 40 μm or less and an average primary particle diameter of 1 μm or less. By containing fine particles having an average primary particle diameter of 1 μm or less, the contact area with the electrolyte solution becomes large, and the diffusion of lithium ions between the electrode and the electrolyte solution can be accelerated, and as a result, the output performance of the battery can be improved.

[0933] As a method for producing the positive electrode active material, a method that is conventional as a method for producing an inorganic compound is used. In particular, in order to produce a spherical or ellipsoidal active material, various methods can be considered, and for example, a method in which a raw material of a transition metal is dissolved or dispersed in a solvent such as water, the pH is adjusted while stirring, a precursor of a recovered sphere is produced, and if necessary, the precursor is dried, a Li source such as LiOH, Li2CO3, or LiNO3 is added, and the mixture is fired at a high temperature to obtain an active material can be mentioned.

[0934] In order to produce the positive electrode, the above-described positive electrode active material can be used alone, or two or more kinds of positive electrode active materials having different compositions can be used in combination in an arbitrary combination or ratio. As a preferable combination in this case, a combination of LiCoO2, LiNi 0.33 Co 0.33 Mn 0.33 LiMn2O4or a combination in which a part of the Mn is replaced with another transition metal or the like, or a combination of LiCoO2or a combination in which a part of the Co is replaced with another transition metal or the like.

[0935] Regarding the content of the above-described positive electrode active material, in terms of a higher battery capacity, it is preferable that the content be 50 to 99.5% by mass of the positive electrode mixture, and more preferably 80 to 99% by mass. In addition, 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. In addition, the upper limit is preferably 99% by mass or less, and 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 capacity is sometimes insufficient. In contrast, if the content is too high, the strength of the positive electrode is sometimes insufficient.

[0936] The above-described positive electrode mixture preferably further includes a binder, a thickener, and a conductive material.

[0937] As the binder, any binder can be used as long as it is a material that is safe for the solvent used when manufacturing the electrode and the electrolyte, and examples thereof include resins such as polyethylene, polypropylene, polyethylene terephthalate, polymethyl methacrylate, aramid, chitosan, alginic acid, polyacrylic acid, polyimide, cellulose, nitrocellulose, and the like; rubber-like polymers such as SBR (styrene-butadiene rubber), isoprene rubber, butadiene rubber, fluororubber, NBR (acrylonitrile-butadiene rubber), ethylene-propylene rubber, and the like; thermoplastic elastomer-like polymers such as styrene-butadiene-styrene block copolymer or hydrogenated product thereof, EPDM (ethylene-propylene-diene terpolymer), styrene-ethylene-butadiene-styrene copolymer, styrene-isoprene-styrene block copolymer or hydrogenated product thereof, and the like; soft resin-like polymers such as syndiotactic-1,2-polybutadiene, polyvinyl acetate, ethylene-vinyl acetate copolymer, propylene-a-olefin copolymer, and the like; fluorine polymers such as polyvinylidene fluoride, polytetrafluoroethylene, vinylidene fluoride copolymer, tetrafluoroethylene-ethylene copolymer, and the like; and polymer compositions having ionic conductivity of alkali metal ions (particularly lithium ions), and the like. One of them can be used alone, or two or more of them can be used in any combination and at any ratio.

[0938] As for the content of the binder, the proportion of the binder in the positive electrode active material layer is usually 0.1% by mass or more, preferably 1% by mass or more, and further preferably 1.5% by mass or more, and is usually 80% by mass or less, preferably 60% by mass or less, and further 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 cannot be sufficiently held, the mechanical strength of the positive electrode is insufficient, and sometimes the battery performance such as cycle characteristics deteriorates. On the other hand, if it is too high, sometimes the battery capacity or the conductivity is reduced.

[0939] As the thickening agent, examples include carboxymethyl cellulose, methyl cellulose, hydroxymethyl cellulose, ethyl cellulose, polyvinyl alcohol, oxidized starch, phosphated starch, casein, polyvinyl pyrrolidone, and salts thereof, and the like. One of them can be used alone, or two or more of them can be used in any combination and at any ratio.

[0940] The proportion of the thickening agent with respect to the active material is usually 0.1% by mass or more, preferably 0.2% by mass or more, and more preferably 0.3% by mass or more, and is usually 5% by mass or less, preferably 3% by mass or less, and more preferably 2% by mass or less. If it is lower than this range, sometimes the coatability is significantly reduced. If it is greater than this range, the proportion of the active material in the positive electrode active material layer is reduced, and sometimes problems such as reduction in the capacity of the battery or increase in the resistance between the positive electrode active materials occur.

[0941] As the above-described conductive material, a publicly known conductive material can be arbitrarily used. As specific examples, there can be mentioned metal materials such as copper, nickel, and the like; graphite such as natural graphite, artificial graphite, and the like; carbon blacks such as acetylene black, ketjen black, channel black, furnace black, lamp black, thermal black, and the like; carbon materials such as needle coke, carbon nanotube, fullerene, VGCF, and the like. Note that they can be used singly or in combination of two or more in an arbitrary combination and ratio. The conductive material is generally 0.01% by mass or more, preferably 0.1% by mass or more, and more preferably 1% by mass or more in the positive electrode active material layer; and is generally used in an amount of 50% by mass or less, preferably 30% by mass or less, and more preferably 15% by mass or less. If the content is lower than the range, the conductivity is sometimes insufficient. On the contrary, if the content is higher than the range, the battery capacity is sometimes reduced.

[0942] As the solvent for forming the slurry, any of water-based solvents and organic-based solvents can be used without particular limitation as long as it is a solvent capable of dissolving or dispersing the positive electrode active material, the conductive material, the binder, and the thickening agent used as necessary. As the water-based solvent, there can be mentioned, for example, water, a mixed solvent of alcohol and water, and the like. As the organic-based solvent, there can be mentioned, for example, aliphatic hydrocarbons such as hexane and the like; aromatic hydrocarbons such as benzene, toluene, xylene, methylnaphthalene, and the like; heterocyclic compounds such as quinoline, pyridine, and the like; ketones such as acetone, methyl ethyl ketone, cyclohexanone, and the like; esters such as methyl acetate, methyl acrylate, and the like; amines such as diethylenetriamine, N,N-dimethylaminopropylamine, and the like; ethers such as diethyl ether, propylene oxide, tetrahydrofuran (THF), and the like; amides such as N-methylpyrrolidone (NMP), dimethylformamide, dimethylacetamide, and the like; aprotic polar solvents such as hexamethylphosphoramide, dimethyl sulfoxide, and the like.

[0943] As the material of the current collector for the positive electrode, there can be mentioned metal materials such as aluminum, titanium, tantalum, stainless steel, nickel, and the like, or alloys thereof; and carbon materials such as carbon cloth, carbon paper, and the like. Among them, the metal material is preferred, and aluminum or an alloy thereof is particularly preferred.

[0944] As the shape of the current collector, in the case of the metal material, there can be mentioned a metal foil, a metal cylinder, a metal coil, a metal plate, a metal film, a porous metal mesh, a punched metal, a foamed metal, and the like, and in the case of the carbon material, there can be mentioned a carbon plate, a carbon film, a carbon cylinder, and the like. Among them, the metal film is preferred. Note that the film can be appropriately formed in a mesh shape. The thickness of the film is arbitrary, and is generally 1 μm or more, preferably 3 μm or more, and more preferably 5 μm or more, and is generally 1 mm or less, preferably 100 μm or less, and more preferably 50 μm or less. If the film is thinner than the range, the strength required as the current collector is sometimes insufficient. On the contrary, if the film is thicker than the range, the handleability is sometimes impaired.

[0945] Further, it is also preferable from the viewpoint of reducing the contact resistance between the current collector and the positive electrode active material layer to coat the surface of the current collector with a conductive aid. As the conductive aid, carbon, or noble metals such as gold, platinum, and silver can be given.

[0946] 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 (the thickness of the positive electrode active material layer on one side when the electrolyte is injected) / (the thickness of the current collector) is preferably 20 or less, more preferably 15 or less, and most preferably 10 or less, and is preferably in the range of 0.5 or more, more preferably 0.8 or more, and most preferably 1 or more. If it is greater than this range, the current collector sometimes generates heat due to Joule heat at the time of high current density charge and discharge. If it is less than this range, the volume ratio of the current collector to the positive electrode active material increases, and the capacity of the battery sometimes decreases.

[0947] The positive electrode can be manufactured by a conventional method. For example, a method in which a slurry-like positive electrode mixture is prepared by adding the above-described binder, thickener, conductive material, solvent, and the like to the above-described positive electrode active material, the slurry-like positive electrode mixture is coated on a current collector and dried, and then pressed to achieve high densification can be given.

[0948] The above-described high densification can be performed by hand pressing, roll pressing, or the like. The density of the positive electrode active material layer is preferably 1.5 g / cm 3 More preferably, 2 g / cm 3 Further preferably, 2.2 g / cm 3 More preferably, 2 g / cm 3 More preferably, 4.5 g / cm 3 Further preferably, 4 g / cm 3 the range. If it exceeds this range, the permeability of the electrolyte to the vicinity of the current collector / active material interface decreases, and particularly, the charge and discharge characteristics at high current density decrease, and sometimes high output cannot be obtained. In addition, if it is less than this range, the conductivity between the active materials decreases, the battery resistance increases, and sometimes high output cannot be obtained.

[0949] In the case where the composition of the present application is used as an electrolytic solution, the area of the positive electrode active material layer is preferably increased relative to the outer surface area of the battery outer packaging case from the viewpoint of improving stability at high output and high temperature. Specifically, the electrode area of the positive electrode relative to the sum of the surface areas of the outer packaging of the secondary battery is preferably 15 times or more, and more preferably 40 times or more, in terms of area ratio. The outer surface area of the battery outer packaging case refers to the total area calculated from the dimensions of the length, width, and thickness of the case portion filled with the power generating element, excluding the protruding portion of the terminal, in the case of a rectangular parallelepiped shape with a bottom. In the case of a circular cylindrical shape with a bottom, the case portion filled with the power generating element, excluding the protruding portion of the terminal, is approximated to the geometric surface area of a cylinder. The sum of the electrode areas of the positive electrode refers to the geometric surface area of the positive electrode mixture layer opposite the negative electrode active material-containing mixture layer, and in the case of a structure in which the positive electrode mixture layer is formed on both sides with the current collector foil interposed therebetween, refers to the sum of the areas of the respective faces calculated separately.

[0950] The thickness of the positive 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 thickness of the core material metal foil is preferably 10 μm or more, and more preferably 20 μm or more, as a lower limit, for a single face of the current collector, and is preferably 500 μm or less, and more preferably 450 μm or less.

[0951] Further, a positive plate obtained by adhering a substance of a different composition on the surface of the above-described positive plate can be used. As the surface adhering substance, oxides such as alumina, silica, titania, zirconia, magnesia, calcia, boria, antimony oxide, bismuth oxide, sulfates such as lithium sulfate, sodium sulfate, potassium sulfate, magnesium sulfate, calcium sulfate, aluminum sulfate, carbonates such as lithium carbonate, calcium carbonate, magnesium carbonate, and carbon can be mentioned.

[0952] <NEGATIVE ELECTRODE>

[0953] The negative electrode is composed of a negative electrode active material layer containing a negative electrode active material, and a current collector.

[0954] As the negative electrode material, any negative electrode material capable of electrochemically absorbing and releasing lithium ions can be used without particular limitation. As specific examples, carbon materials, alloy-based materials, lithium-containing metal complex oxide materials, and electrically conductive polymers can be mentioned. One of them can be used alone, or two or more of them can be used in any combination.

[0955] As the negative electrode active material, there can be mentioned pyrolysis products of various organic matters under various thermal decomposition conditions, or carbonaceous materials capable of absorbing and releasing lithium such as artificial graphite, natural graphite, and the like; metal oxide materials capable of absorbing and releasing lithium such as tin oxide, silicon oxide, and the like; lithium metal; various lithium alloys; lithium-containing metal composite oxide materials, and the like. Two or more of these negative electrode active materials can be mixed and used.

[0956] As the carbonaceous material capable of absorbing and releasing lithium, it is more preferable that the carbonaceous material be one selected from the group consisting of natural graphite, artificial graphite, carbonaceous materials obtained by subjecting artificial carbonaceous materials and artificial graphitic materials to heat treatment one or more times in the range of 400°C to 3200°C, carbonaceous materials in which the negative electrode active material layer contains at least two or more carbonaceous materials having different crystallinities and / or the interface of carbonaceous materials having different crystallinities, and carbonaceous materials in which the negative electrode active material layer has the interface of carbonaceous materials having at least two or more different orientations, and in which the initial irreversible capacity of the carbonaceous material and the balance of high current density charge-discharge characteristics are good. In addition, one of these carbon materials can be used alone, or two or more of them can be used in combination in any ratio.

[0957] As the carbonaceous material obtained by subjecting artificial carbonaceous materials and artificial graphitic materials to heat treatment one or more times in the range of 400°C to 3200°C, there can be mentioned coal-based coke, petroleum-based coke, coal-based pitch, petroleum-based pitch, and substances obtained by subjecting these pitches to oxidation treatment, needle coke, pitch coke, and carbonizers obtained by subjecting these to partial graphitization, furnace black, acetylene black, pitch-based carbon fibers, pyrolysis products of various organic matters, carbonizable organic matters and their carbides, or solutions obtained by dissolving carbonizable organic matters in low molecular organic solvents such as benzene, toluene, xylene, quinoline, n-hexane, and the like, and their carbides, and the like.

[0958] As the metal material used as the negative electrode active material (except for lithium-titanium composite oxides), any one of lithium simple substance, simple metal and alloy forming lithium alloy, or oxides, carbides, nitrides, silicides, sulfides, or phosphides of these, and the like can be used as long as it can absorb and release lithium, and there is no particular limitation. As the simple metal and alloy forming lithium alloy, it is preferable that the material contain Group IIIA and Group IVA metal and semimetal elements, and it is more preferable that the simple metal be aluminum, silicon, and tin (hereinafter referred to as "specific metal elements"), and the alloy or compound containing these atoms. One of these can be used alone, or two or more of them can be used in combination in any ratio.

[0959] As the negative active material having an atom selected from at least one of the specific metal elements, there can be mentioned a metal simple substance of any one of the specific metal elements, an alloy containing two or more of the specific metal elements, an alloy containing one or two or more of the specific metal elements and other one or two or more metal elements, and a compound containing one or two or more of the specific metal elements, and a complex compound such as an oxide, a carbide, a nitride, a silicide, a sulfide or a phosphide of the compound. By using these metal simple substances, alloys or metal compounds as the negative active material, high capacity of the battery can be achieved.

[0960] Further, there can be mentioned a compound obtained by complexly bonding these complex compounds with a metal simple substance, an alloy or a non-metal element. Specifically, for example, in the case of silicon or tin, an alloy of these elements with a metal that does not function as a negative electrode can also be used. For example, in the case of tin, a complex compound containing five to six elements, for example, a combination of tin with a metal that functions as a negative electrode other than silicon, a metal that does not function as a negative electrode, and a non-metal element can also be used.

[0961] Specifically, there can be mentioned Si simple substance, SiB4, SiB6, Mg2Si, Ni2Si, TiSi2, MoSi2, CoSi2, NiSi2, CaSi2, CrSi2, Cu6Si, FeSi2, MnSi2, NbSi2, TaSi2, VSi2, WSi2, ZnSi2, SiC, Si3N4, Si2N2O, SiO v (0 < v < 2), LiSiO or tin simple substance, SnSiO3, LiSnO, Mg2Sn, SnO w (0 < w < 2).

[0962] Further, there can be mentioned a composite material having Si or Sn as a first constituent element, and containing a second and a third constituent element. 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.

[0963] In particular, from the viewpoint of obtaining high battery capacity and excellent battery characteristics, as the above metal material, a simple substance of silicon or tin (may contain a trace amount of impurities), SiO v (0 < v < 2), SnO w (0 < w < 2), Si-Co-C composite material, Si-Ni-C composite material, Sn-Co-C composite material, Sn-Ni-C composite material.

[0964] As the lithium-containing metal composite oxide material used as the negative active material, there is no particular limitation as long as it can absorb and release lithium, and from the aspect of high current density charge-discharge characteristics, a material containing titanium and lithium is preferable, a lithium-containing composite metal oxide material containing titanium is more preferable, and a lithium-titanium composite oxide (hereinafter, simply referred to as "lithium-titanium composite oxide") is further preferable. That is, if a lithium-titanium composite oxide having a spinel structure is contained in the negative active material for electrolytic solution batteries and used, the output resistance is greatly reduced, and thus it is particularly preferable.

[0965] As the above-described lithium-titanium composite oxide, a compound represented by the general formula is preferable:

[0966] Li x Ti y M z O4

[0967] [In the formula, M represents at least one element selected from Na, K, Co, Al, Fe, Ti, Mg, Cr, Ga, Cu, Zn, and Nb.]

[0968] In the above-described composition,

[0969] (i) 1.2 ≤ x ≤ 1.4, 1.5 ≤ y ≤ 1.7, z = 0

[0970] (ii) 0.9 ≤ x ≤ 1.1, 1.9 ≤ y ≤ 2.1, z = 0

[0971] (iii) 0.7 ≤ x ≤ 0.9, 2.1 ≤ y ≤ 2.3, z = 0

[0972] The balance of the battery performance of the structure of (i) 1.2 ≤ x ≤ 1.4, 1.5 ≤ y ≤ 1.7, z = 0 is good, and thus it is particularly preferable.

[0973] A particularly preferable representative composition of the above-described compound is Li 4 / 3 Ti 5 / 3 O4 for (i), Li1Ti2O4 for (ii), and Li 4 / 5 Ti 11 / 5 O4 for (iii). Furthermore, as a preferable example for the structure of Z ≠ 0, Li 4 / 3Ti 4 / 3 Al 1 / 3 O4 can be given.

[0974] The above-described negative electrode mixture preferably further contains a binder, a thickening agent, and a conductive material.

[0975] As the binder described above, the same binder as the binder described above that can be used in the positive electrode can be given. The proportion of the binder with respect to the negative electrode active material is preferably 0.1% by mass or more, further preferably 0.5% by mass or more, particularly preferably 0.6% by mass or more, and in addition, is preferably 20% by mass or less, more preferably 15% by mass or less, further preferably 10% by mass or less, particularly preferably 8% by mass or less. If the proportion of the binder with respect to the negative electrode active material is greater than the range described above, the proportion of the binder that does not contribute to the capacity of the battery increases, and sometimes, the capacity of the battery decreases. In addition, if it is lower than the range described above, sometimes, the strength of the negative electrode decreases.

[0976] In particular, in the case where a rubbery polymer typified by SBR is contained as a main component, the proportion of the binder with respect to the negative electrode active material is usually 0.1% by mass or more, preferably 0.5% by mass or more, and further preferably 0.6% by mass or more, and is usually 5% by mass or less, preferably 3% by mass or less, and further preferably 2% by mass or less. In addition, in the case where a fluorine-based polymer typified by polyvinylidene fluoride is contained as a main component, the proportion with respect to the negative electrode active material is usually 1% by mass or more, preferably 2% by mass or more, and further preferably 3% by mass or more, and is usually 15% by mass or less, preferably 10% by mass or less, and further preferably 8% by mass or less.

[0977] As the thickening agent described above, the same substance as the thickening agent described above that can be used in the positive electrode can be given. The proportion of the thickening agent with respect to the negative electrode active material is usually 0.1% by mass or more, preferably 0.5% by mass or more, and further preferably 0.6% by mass or more, and is usually 5% by mass or less, preferably 3% by mass or less, and further preferably 2% by mass or less. If the proportion of the thickening agent with respect to the negative electrode active material is lower than the range described above, sometimes, the coatability significantly decreases. In addition, if it is greater than the range described above, the proportion of the negative electrode active material in the negative electrode active material layer decreases, and sometimes, there is a problem in that the capacity of the battery decreases or the resistance between the negative electrode active materials increases.

[0978] As the conductive material of the negative electrode, a metal material such as copper or nickel; a carbon material such as graphite or carbon black; or the like can be given.

[0979] As the solvent used for forming the slurry, any one of an aqueous solvent and an organic solvent can be used as long as it is a solvent that can dissolve or disperse the negative electrode active material, the binder, and the thickening agent and the conductive material used as necessary.

[0980] As the water-based solvent, water, alcohol, and the like can be given. As the organic solvent, N-methylpyrrolidone (NMP), dimethylformamide, dimethylacetamide, methyl ethyl ketone, cyclohexanone, methyl acetate, methyl acrylate, diethylenetriamine, N,N-dimethylaminopropylamine, tetrahydrofuran (THF), toluene, acetone, diethyl ether, dimethylacetamide, hexamethylphosphoramide, dimethyl sulfoxide, benzene, xylene, quinoline, pyridine, methylnaphthalene, hexane, and the like can be given.

[0981] As the material of the negative electrode current collector, copper, nickel, stainless steel, and the like can be given. Among them, from the viewpoint of easy processing into a thin film and the viewpoint of cost, a copper foil is preferable.

[0982] 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 sometimes excessively decreases, and on the contrary, if it is too thin, handling sometimes becomes difficult.

[0983] The negative electrode can be produced by a conventional method. For example, a method in which a slurry is produced by adding the above-described binder, thickener, conductive material, solvent, and the like to the above-described negative electrode, the slurry is coated on the current collector and dried, and then pressed to achieve high densification can be given. In addition, in the case of using an alloy material, a method in which a thin film layer (negative electrode active material layer) containing the above-described negative electrode active material is formed by a method such as an evaporation method, a sputtering method, a plating method, and the like can also be given.

[0984] The electrode structure at the time of polarization of the negative electrode active material is not particularly limited, and the density of the negative electrode active material present on the current collector is preferably 1 g-Cm -3 Further preferably, 1.2 g-Cm -3 Particularly preferably, 1.3 g-Cm -3 Further, 2.2 g-Cm -3 More preferably, 2.1 g-Cm -3 Further preferably, 2.0 g-Cm -3 Particularly preferably, 1.9 g-Cm -3 If the density of the negative electrode active material present on the current collector exceeds the above range, there are cases in which the negative electrode active material particles are broken, the initial irreversible capacity increases, and the high current density charge-discharge characteristics deteriorate due to the decrease in the permeability of the electrolyte to the vicinity of the current collector / negative electrode active material interface. On the other hand, if it is lower than the above range, there are cases in which the conductivity between the negative electrode active materials decreases, the battery resistance increases, and the capacity per unit volume decreases.

[0985] The thickness of the negative electrode plate is designed in accordance with the positive electrode plate to be used, and is not particularly limited, but the thickness of the adhesive layer, excluding the thickness of the core metal foil, is typically 15 μm or greater, preferably 20 μm or greater, more preferably 30 μm or greater, and is typically 300 μm or less, preferably 280 μm or less, more preferably 250 μm or less.

[0986] Further, a negative electrode plate obtained by adhering a substance having a different composition from that of the negative electrode plate to the surface of the negative electrode plate can be used. As the surface adhering substance, oxides such as alumina, silica, titania, zirconia, magnesia, calcia, boria, antimony oxide, bismuth oxide, sulfates such as lithium sulfate, sodium sulfate, potassium sulfate, magnesium sulfate, calcium sulfate, aluminum sulfate, carbonates such as lithium carbonate, calcium carbonate, magnesium carbonate, and the like can be given.

[0987] <Separator>

[0988] Preferably, the lithium ion secondary battery of the present application further comprises a separator.

[0989] The material or shape of the above-mentioned separator is not particularly limited as long as it is stable in the electrolyte solution and has excellent liquid retention properties, and a publicly known material or shape can be used. Among them, a resin, glass fiber, inorganic substance, or the like formed of a material stable with respect to the composition (electrolyte solution) of the present application is preferably used, and a porous sheet or nonwoven fabric-like material having excellent liquid retention properties, or the like is used.

[0990] As the material of the resin or glass fiber separator, for example, polyolefins such as polyethylene and polypropylene, aramid, polytetrafluoroethylene, polyethersulfone, glass filter, and the like can be used. A polypropylene / polyethylene double-layer film, a polypropylene / polyethylene / polypropylene triple-layer film, and the like can be used, and these materials can be used singly or in combination of two or more in any combination and ratio. Among them, in terms of the permeability or shutdown effect of the electrolyte solution, the above-mentioned separator is preferably a porous sheet or nonwoven fabric or the like using polyolefins such as polyethylene and polypropylene as a raw material.

[0991] The thickness of the separator is arbitrary, and is typically 1 μm or greater, preferably 5 μm or greater, and further preferably 8 μm or greater, and is typically 50 μm or less, preferably 40 μm or less, and further preferably 30 μm or less. If the separator is too thin than the above-mentioned range, the insulation or mechanical strength is sometimes reduced. Further, if it is too thick than the above-mentioned range, not only the battery performance such as rate characteristics is sometimes reduced, but also the energy density of the entire electrolyte battery is sometimes reduced.

[0992] Further, in the case where a porous sheet, nonwoven fabric or the like porous material is used as the separator, the porosity of the separator is arbitrary, but is usually 20% or more, preferably 35% or more, and further preferably 45% or more, and is usually 90% or less, preferably 85% or less, and further preferably 75% or less. If the porosity is too small than the above range, there is a tendency that the film resistance becomes large and the rate characteristics deteriorate. In addition, if it is too large than the above range, there is a tendency that the mechanical strength of the separator decreases and the insulation property decreases.

[0993] Further, the average pore diameter of the separator is also arbitrary, and is usually 0.5 μm or less, preferably 0.2 μm or less, and is usually 0.05 μm or more. If the average pore diameter is larger than the above range, short circuiting easily occurs. In addition, if it is lower than the above range, the film resistance sometimes becomes large and the rate characteristics decrease.

[0994] On the other hand, as the material of the inorganic substance, for example, an oxide such as alumina, silica or the like; a nitride such as aluminum nitride, silicon nitride or the like; a sulfate such as barium sulfate, calcium sulfate or the like can be used, and a material in a granular shape or a fibrous shape can be used.

[0995] As the form, a nonwoven fabric, a woven fabric, a microporous film or the like thin film shape can be used. In the case of the thin film shape, a material having a pore diameter of 0.01 μm to 1 μm and a thickness of 5 μm to 50 μm is suitably used. In addition to the above independent thin film shape, a separator in which a composite porous layer containing the above inorganic substance particles is formed on the surface layer of the positive electrode and / or the negative electrode using a binder made of a resin can be used. For example, a porous layer can be formed on both surfaces of the positive electrode using alumina particles having a 90% particle diameter of less than 1 μm using a fluorine resin as the binder.

[0996] <Design of battery>

[0997] The electrode group can be either of a stacked structure electrode group in which the above positive electrode plate and negative electrode plate are separated by the above separator, and a structure electrode group in which the above positive electrode plate and negative electrode plate are wound in a spiral shape with the above separator interposed therebetween. The volume ratio of the electrode group in the battery inner volume (hereinafter referred to as electrode group occupancy) is usually 40% or more, preferably 50% or more, and is usually 90% or less, preferably 80% or less.

[0998] If the electrode group occupancy is lower than the above range, the battery capacity becomes small. In addition, if it is higher than the above range, the void space is small, and there is a tendency that the members expand due to the battery reaching a high temperature, or the vapor pressure of the liquid component of the electrolyte becomes high, thereby causing the internal pressure to increase, and various characteristics as a battery such as repeated charge and discharge performance, high temperature storage or the like decrease, and sometimes the air release valve for releasing the internal pressure to the outside operates.

[0999] The current collecting structure is not particularly limited, and in order to more effectively achieve the improvement in the charge and discharge characteristics of high current density brought about by the composition (electrolyte) of the present application, a structure in which the resistance of the wiring portion and the joint portion is reduced is preferred. In the case where the internal resistance is thus reduced, the effects of using the composition (electrolyte) of the present application are particularly favorably exhibited.

[1000] In the case where the electrode group is of the stacked structure described above, a structure in which the metal core portion of each electrode layer is bundled and welded to the terminal is suitably used. In the case where the area of the single electrode sheet is large, the internal resistance becomes large, and therefore it is also suitably used to provide a plurality of terminals in the electrode to reduce the resistance. In the case where the electrode group is of the wound structure described above, a plurality of lead structures are provided on the positive electrode and the negative electrode, respectively, and by bundling to the terminal, the internal resistance can be reduced.

[1001] The material of the exterior case is not particularly limited as long as it is a stable material with respect to the electrolyte used. Specifically, a nickel-plated steel sheet, a stainless steel, aluminum or an aluminum alloy, a magnesium alloy, or the like, or a laminate film (laminated film) of a resin and an aluminum foil can be used. From the viewpoint of light weight, a metal of aluminum or an aluminum alloy, a laminate film is suitably used.

[1002] In the case where a metal is used for the exterior case, an exterior case in which metals are fusion-bonded to each other by laser welding, resistance welding, or ultrasonic welding to form a sealed structure, or an exterior case in which a metal is used via a resin-made sealing gasket to form a riveted structure can be given. In the case where the above-described laminate film is used for the exterior case, an exterior case in which resin layers are fusion-bonded to each other by heat to form a sealed structure, or the like can be given. In order to improve the sealing property, a resin different from the resin used in the laminate film can be interposed between the above-described resin layers. In particular, in the case where the resin layers are fusion-bonded by heat via the current collecting terminal to form a sealed structure, a joint of a metal and a resin is formed, and therefore as the spacer resin, a resin having a polar group or a modified resin into which a polar group is introduced is suitably used.

[1003] The shape of the lithium ion secondary battery of the present application is arbitrary, and for example, a cylindrical shape, a square shape, a laminate type, a coin type, a large size, or the like can be given. Note that the shape and the constitution of the positive electrode, the negative electrode, and the separator can be changed depending on the shape of the battery.

[1004] In addition, a lithium ion secondary battery having the following feature is also one preferred mode: provided with a positive electrode, a negative electrode, and the above-described electrolyte, the positive electrode is provided with a positive electrode current collector and a positive electrode active material layer containing a positive electrode active material, and the positive electrode active material contains Mn. Since the positive electrode active material layer containing the positive electrode active material containing Mn is provided, the high-temperature storage characteristics of the above-described lithium ion secondary battery are further more excellent.

[1005] As the positive electrode active material containing the above Mn, from the viewpoint of being able to provide a lithium ion secondary battery with high energy density and high output, LiMn 1.5 Ni 0.5 O4, LiNi 0.5 Co 0.2 Mn 0.3 O2, LiNi 0.6 Co 0.2 Mn 0.2 O2.

[1006] In addition, as the positive electrode active material containing the above Mn, from the viewpoint of being able to provide a lithium ion secondary battery with high capacity, LiNi 0.6 Co 0.2 Mn 0.2 O2, LiNi 0.8 Co 0.1 Mn 0.1 O2.

[1007] The content of the above 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. Furthermore, the upper limit is preferably 99% by mass or less, and 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 capacitance is sometimes insufficient. On the contrary, if the content is too high, the strength of the positive electrode is sometimes insufficient.

[1008] The above positive electrode active material layer can further contain an electrically conductive material, a thickening agent, and a binder.

[1009] As the binder, any binder can be used as long as it is a material that is safe with respect to the solvent used when manufacturing the electrode and the electrolyte, and examples thereof include 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 hydrogenated product thereof, EPDM (ethylene-propylene-diene terpolymer), styrene-ethylene-butadiene-ethylene copolymer, styrene-isoprene-styrene block copolymer or hydrogenated product thereof, syndiotactic-1,2-polybutadiene, polyvinyl acetate, ethylene-vinyl acetate copolymer, propylene-a-olefin copolymer, fluorinated polyvinylidene fluoride, tetrafluoroethylene-ethylene copolymer, and ion-conducting high-molecular composition having alkali metal ions (particularly, lithium ions). Note that these substances can be used singly or in combination of two or more in any combination and ratio.

[1010] The content of the binder is usually 0.1% by mass or more, preferably 1% by mass or more, and further preferably 1.5% by mass or more, and is usually 80% by mass or less, preferably 60% by mass or less, and further preferably 40% by mass or less, and most preferably 10% by mass or less, with respect to the proportion of the binder in the positive electrode active material layer. If the proportion of the binder is too low, the positive electrode active material cannot be sufficiently held, the mechanical strength of the positive electrode is insufficient, and sometimes the battery performance such as cycle characteristics deteriorates. On the other hand, if it is too high, sometimes the battery capacity or the conductivity is reduced.

[1011] As the thickening agent, examples include carboxymethyl cellulose, methyl cellulose, hydroxymethyl cellulose, ethyl cellulose, polyvinyl alcohol, oxidized starch, phosphated starch, casein, and salts thereof. One of these substances can be used singly, or two or more of these substances can be used in combination in any combination and ratio.

[1012] The proportion of the thickening agent with respect to the active material is usually 0.1% by mass or more, preferably 0.2% by mass or more, and more preferably 0.3% by mass or more, and is usually 5% by mass or less, preferably 3% by mass or less, and more preferably 2% by mass or less. If it is less than this range, sometimes the coatability is significantly reduced. If it is greater than this range, the proportion of the active material in the positive electrode active material layer is reduced, and sometimes problems such as a reduction in the capacity of the battery or an increase in the resistance between the positive electrode active materials occur.

[1013] As the above-mentioned conductive material, a publicly known conductive material can be arbitrarily used. As specific examples, there can be mentioned metal materials such as copper and nickel, graphite (Graphite) such as natural graphite and artificial graphite, carbon black such as acetylene black, and amorphous carbon such as needle coke. Note that one of them can be used alone, or two or more of them can be used in combination in any ratio. The conductive material is used in the positive electrode active material layer in an amount of usually 0.01% by mass or more, preferably 0.1% by mass or more, and more preferably 1% by mass or more, and usually 50% by mass or less, preferably 30% by mass or less, and more preferably 15% by mass or less. If the content is lower than the range, the conductivity is sometimes insufficient. On the contrary, if the content is higher than the range, the battery capacity is sometimes reduced.

[1014] From the viewpoint of further improving the high-temperature storage characteristics, the above-mentioned positive electrode current collector is preferably composed of a valve metal or an alloy thereof. As the above-mentioned valve metal, there can be mentioned aluminum, titanium, tantalum, chromium, and the like. The above-mentioned positive electrode current collector is more preferably composed of aluminum or an alloy of aluminum.

[1015] From the viewpoint of further improving the high-temperature storage characteristics, the part of the above-mentioned lithium ion secondary battery which is in contact with the electrolyte among the parts electrically connected to the above-mentioned positive electrode current collector is also preferably composed of a valve metal or an alloy thereof. It is particularly preferable that the part of the battery case and the lead, safety valve, and the like housed in the above-mentioned battery case which is electrically connected to the positive electrode current collector and is in contact with the nonaqueous electrolyte be composed of a valve metal or an alloy thereof. A stainless steel covered with a valve metal or an alloy thereof can be used.

[1016] The above-mentioned positive electrode can be produced by, for example, a method in which a slurry-like positive electrode mixture is prepared by adding the above-mentioned binder, thickening agent, conductive material, solvent, and the like to the above-mentioned positive electrode active material, the slurry-like positive electrode mixture is coated on the above-mentioned positive electrode current collector and dried, and then the positive electrode is pressed to achieve high density.

[1017] The above-mentioned negative electrode can be composed of, for example, a negative electrode active material, a binder, and the like.

[1018] A component of a lithium ion secondary battery of the present application is also one of the present application.

[1019] The above-mentioned double-layer capacitor has a positive electrode, a negative electrode, and the above-mentioned electrolyte.

[1020] In the above-mentioned double-layer capacitor, at least one of the positive electrode and the negative electrode is a polarizable electrode, and as the polarizable electrode and the non-polarizable electrode, the electrodes described in detail in Japanese Patent Application Laid-Open No. 9-7896 can be used.

[1021] The polarization electrode using activated carbon as the main body preferably contains a non-activated carbon having a large specific surface area and a conductive agent such as carbon black that imparts electronic conductivity. The polarization electrode can be formed by various methods. For example, activated carbon powder, carbon black, and a phenol-based resin are mixed, and after being press-formed, the mixture is calcined in a non-activated gas atmosphere and a water vapor atmosphere to impart activation, whereby a polarization electrode containing activated carbon and carbon black can be formed. Preferably, the polarization electrode is joined to a current collector by a conductive adhesive or the like.

[1022] Further, the activated carbon powder, carbon black, and a binder can be mixed in the presence of an alcohol to form a sheet, and the sheet can be dried to produce a polarization electrode. The binder is, for example, polytetrafluoroethylene. Further, the activated carbon powder, carbon black, a binder, and a solvent can be mixed to produce a slurry, the slurry can be applied to a metal foil of a current collector, and the slurry can be dried to produce a polarization electrode integrated with the current collector.

[1023] The polarization electrode using activated carbon as the main body can be used for both electrodes to produce an electric double layer capacitor, or can be configured to use a non-polarizable electrode on one side, such as a configuration in which a positive electrode using a battery active material such as a metal oxide as the main body is combined with a negative electrode using a polarization electrode using activated carbon as the main body, or a configuration in which a negative electrode using a carbon material capable of reversibly absorbing and desorbing lithium ions as the main body or a negative electrode using lithium metal or a lithium alloy is combined with a positive electrode using a polarization electrode using activated carbon as the main body.

[1024] Further, a carbonaceous material such as carbon black, graphite, expanded graphite, porous carbon, carbon nanotubes, carbon nanohorns, or Ketjen black can be used instead of or in combination with activated carbon.

[1025] As the non-polarizable electrode, a carbon material capable of reversibly absorbing and desorbing lithium ions is preferably used as the main body, and an object in which lithium ions are absorbed in the carbon material is used as the electrode. In this case, a lithium salt is used as the electrolyte. According to the electric double layer capacitor configured in this way, a further higher voltage resistance of more than 4 V is obtained.

[1026] The solvent used for preparing the slurry in the production of the electrode is preferably a solvent that dissolves the binder, and is appropriately selected from N-methylpyrrolidone, dimethylformamide, toluene, xylene, isoforone, methyl ethyl ketone, ethyl acetate, methyl acetate, dimethyl phthalate, ethanol, methanol, butanol, or water, in accordance with the type of the binder.

[1027] As the activated carbon used in the polarization electrode, there are phenol resin-based activated carbon, coconut shell-based activated carbon, petroleum coke-based activated carbon, and the like. Among these, in terms of obtaining a large capacity, it is preferable to use petroleum coke-based activated carbon or phenol resin-based activated carbon. Further, among the activation treatment methods of activated carbon, there are a water vapor activation treatment method, a molten KOH activation treatment method, and the like, and in terms of obtaining a larger capacity, it is preferable to use activated carbon that has been subjected to the molten KOH activation treatment method.

[1028] As the preferable conductive agent used in the polarization electrode, carbon black, ketjen black, acetylene black, natural graphite, artificial graphite, metal fiber, conductive titanium oxide, and ruthenium oxide can be mentioned. As to the mixing amount of the conductive agent such as carbon black used in the polarization electrode, in order to obtain good conductivity (low internal resistance), and since mixing too much will cause the product capacity to decrease, it is preferable to use 1 to 50 mass% in the total amount of the active carbon.

[1029] Further, as the active carbon used in the polarization electrode, in order to obtain a double layer capacitor with large capacity and low internal resistance, it is preferable to use an active carbon with an average particle diameter of 20 μm or less and a specific surface area of 1500 to 3000 m 2 / g. Further, as the preferable carbon material used for the electrode mainly composed of a carbon material capable of reversibly absorbing and desorbing lithium ions, natural graphite, artificial graphite, mesocarbon microbead, graphitized whisker, vapor phase growth carbon fiber, a fired product of furfuryl alcohol resin, or a fired product of Novolak resin can be mentioned.

[1030] The current collector only needs to have chemical corrosion resistance and electrochemical corrosion resistance. As the current collector of the polarization electrode mainly composed of active carbon, stainless steel, aluminum, titanium, or tantalum can be preferably used. Among these, stainless steel or aluminum is a particularly preferable material in terms of both the characteristics and the price of the resulting double layer capacitor. As the current collector of the electrode mainly composed of a carbon material capable of reversibly absorbing and desorbing lithium ions, stainless steel, copper, or nickel is preferably used.

[1031] Further, in order to cause the carbon material capable of reversibly absorbing and desorbing lithium ions to absorb lithium ions in advance, the following methods are available: (1) a method of mixing powdered lithium in advance in the carbon material capable of reversibly absorbing and desorbing lithium ions; (2) a method of placing a lithium foil on an electrode formed of a carbon material capable of reversibly absorbing and desorbing lithium ions and a binder, bringing the lithium foil into electrical contact with the electrode, ionizing lithium by immersing the electrode in an electrolyte in which a lithium salt is dissolved, and causing lithium ions to be taken into the carbon material; and (3) a method of placing an electrode formed of a carbon material capable of reversibly absorbing and desorbing lithium ions and a binder on the negative electrode side, placing lithium metal on the positive electrode side, immersing in a non-aqueous electrolyte in which a lithium salt is used as the electrolyte, and electrochemically causing lithium to be taken into the carbon material in an ionized state by passing an electric current.

[1032] As the double layer capacitor, a generally known roll type double layer capacitor, a laminate type double layer capacitor, a coin type double layer capacitor, and the like are available, and the above double layer capacitor can also be provided in these forms.

[1033] For example, a wound-type electric double layer capacitor is assembled by winding a positive electrode and a negative electrode of a laminate (electrode) including a current collector and an electrode layer with a separator interposed therebetween to produce a wound element, incorporating the wound element in an aluminum or the like case, filling an electrolytic solution, preferably a nonaqueous electrolytic solution, and sealing with a rubber seal to thereby seal.

[1034] As the separator, a publicly known material and configuration can be used. For example, a polyethylene porous film, polytetrafluoroethylene, a nonwoven fabric of polypropylene fibers or glass fibers, cellulose fibers, or the like can be mentioned.

[1035] Further, by a publicly known method, a laminate-type electric double layer capacitor obtained by laminating sheet-like positive and negative electrodes with an electrolytic solution and a separator interposed therebetween, or a coin-type electric double layer capacitor obtained by fixing a positive electrode and a negative electrode with a gasket with an electrolytic solution and a separator interposed therebetween to form a coin shape can also be produced.

[1036] The composition (electrolytic solution) of the present application is useful as an electrolytic solution for a large-sized lithium ion secondary battery for a hybrid automobile, a distributed power source, an electric double layer capacitor, and the like.

[1037] Examples

[1038] Hereinafter, the present application will be described with examples, but the present application is not limited to these examples.

[1039] Synthesis of CF2=CF-O-CH2CF=CF2

[1040] [Chemical Formula 97]

[1041]

[1042] A magnetic stirrer bar, 2,2,2-trifluoro-2-propen-l-ol (compound 2, 3.3 g, 30 mmol), and sodium fluoride powder (0.6 g, 15 mmol) were placed in a reaction vessel, degassed, and then subjected to nitrogen substitution. The reaction vessel was cooled with liquid nitrogen, and HFPO gas (compound 1, 1.6 g, 9.9 mmol) was introduced. After stirring at room temperature for 24 hours, the reaction liquid was distilled under reduced pressure to obtain a transparent liquid. The liquid was neutralized with 4N KOH aqueous solution, and the obtained white solid was collected by filtration and dried under vacuum at room temperature to thereby obtain compound 4 (2.5 g, 9.0 mmol). The target compound 5 (1.6 g, 8.4 mmol) was obtained by thermal decomposition at 250°C and recovery of the volatile component in a cooling trap (-78°C).

[1043] Preparation of electrolyte

[1044] Examples and Comparative Examples

[1045] Each component was mixed so as to become the composition described in Tables 1 and 2, and LiPF6 was added to the mixture to achieve a concentration of 1.0 mol / L, to produce a nonaqueous electrolyte. Note that in Tables 1 and 2, the amount of each solvent is the amount when the entire solvent is taken as 100% by volume, and the amount of the additive is the amount when the total amount of the electrolyte is taken as 100% by mass.

[1046] (Manufacture of aluminum-laminated lithium-ion secondary battery)

[1047] [Manufacture of positive electrode]

[1048] LiNi 0.6 Co 0.2 Mn 0.2 O2(NMC) 93 mass%, acetylene black 3 mass% as a conductive material, and polyvinylidene fluoride (PVdF) 4 mass% as a binder were mixed in an N-methylpyrrolidone solvent to perform slurry formation. The obtained slurry was coated on one side of an aluminum foil having a thickness of 15 μm to which a conductive aid had been previously applied, dried, and roll-pressed using a press machine, and cut into a shape having an active material layer size of 50 mm in width by 30 mm in length and having an uncoated portion of 5 mm in width by 9 mm in length, to produce a positive electrode.

[1049] [Manufacture of negative electrode]

[1050] To 98 parts by mass of a carbonaceous material (graphite), 1 part by mass of an aqueous dispersion of sodium carboxymethyl cellulose (concentration of sodium carboxymethyl cellulose 1 mass%) and 1 part by mass of an aqueous dispersion of styrene-butadiene rubber (concentration of styrene-butadiene rubber 50 mass%) were added as a thickening agent and a binder, and mixed and slurry- formed using a disperser. The obtained slurry was coated on a copper foil having a thickness of 10 μm and dried, and after calendering using a press machine, cut into a shape having an active material layer size of 52 mm in width by 32 mm in length and having an uncoated portion of 5 mm in width by 9 mm in length, to produce a negative electrode.

[1051] [Manufacture of aluminum-laminated battery cell]

[1052] The above-described positive electrode was opposed to the negative electrode via a microporous polyethylene film (separator) having a thickness of 20 μm, and the above-described obtained nonaqueous electrolyte was injected, and after the nonaqueous electrolyte had sufficiently penetrated the separator, etc., the lithium-ion secondary battery was sealed and subjected to pre-charging and aging, to produce a lithium-ion secondary battery.

[1053] (Measurement of battery characteristics)

[1054] [Cycling characteristics test]

[1055] The lithium ion secondary battery manufactured above was charged at 25°C under a state of being clamped and pressurized with a plate by constant current-constant voltage charging (hereinafter referred to as CC / CV charging) at a current equivalent to 1C (0.1C cut) to 4.2V, and then discharged at a constant current of 1C to 3V, which was taken as one cycle, and the initial discharge capacity was calculated from the discharge capacity of the third cycle. Here, 1C means a current value at which the reference capacity of the battery is discharged in 1 hour, and for example, 0.2C means a current value of 1 / 5 thereof. The cycle was performed again, and the discharge capacity after 200 cycles was measured. The proportion of the discharge capacity after 200 cycles to the initial discharge capacity was calculated, and taken as the cycle capacity retention rate (%).

[1056] (Discharge capacity after 200 cycles) ÷ (Initial discharge capacity) x 100 = Capacity retention rate (%)

[1057] The results calculated by taking the value of Comparative Example 1 as 1 are shown in Table 1 and Table 2.

[1058] [IV resistance evaluation]

[1059] The battery after the evaluation of the initial discharge capacity was charged at 25°C at a constant current of 1C to a capacity of half the initial discharge capacity. This was discharged at 1.0C, and the voltage at 10 seconds of discharge was measured. The resistance was calculated from the drop in the voltage at discharge, and taken as the IV resistance.

[1060] The results calculated by taking the value of Comparative Example 1 as 1 are shown in Table 1 and Table 2.

[1061] [Gas generation amount]

[1062] The volume of the lithium ion secondary battery manufactured above and the volume of the lithium ion secondary battery after 200 cycles above were measured by the Archimedes method, and the gas generation amount (ml) was calculated from the volume change.

[1063] The results calculated by taking the value of Comparative Example 1 as 1 are shown in Table 1 and Table 2.

[1064] [Table 1]

[1065]

[1066] [Table 2]

[1067]

[1068] The abbreviations in the tables are as described below.

[1069] EC: ethylene carbonate

[1070] EMC: Methyl ethyl carbonate (A): HCF2CF2-O-CH2CF2CF2H (compound (2), fluorine content: 65.5 mass%) (B): CF2=CF-O-CH2CF=CF2 (compound (1), fluorine content: 59.4 mass%)

Claims

1. An electrolyte, characterized in that, Compounds comprising the following general formula (1): Rf 1 -O-Rf 2 (1) In equation (1), Rf 1 and Rf 2 Whether the groups are the same or different, they are fluoroalkenyl groups with 2 to 4 carbon atoms.

2. The electrolyte according to claim 1, wherein, In the above formula (1), Rf 1 and Rf 2 These are mutually different groups.

3. The electrolyte according to claim 2, wherein, In the above formula (1), Rf 1 and Rf 2 One of them is a fluoroalkenyl group with 2 carbon atoms, and the other is a fluoroalkenyl group with 3 carbon atoms.

4. The electrolyte according to any one of claims 1 to 3, wherein, The compound represented by the general formula (1) is CF2=CF-O-CH2CF=CF2.

5. The electrolyte according to any one of claims 1 to 3, wherein, The content of the compound represented by the general formula (1) relative to the electrolyte is more than 0.00000001 ppm by mass and less than 50000 ppm by mass.

6. The electrolyte according to any one of claims 1 to 3, wherein, The content of the compound represented by the general formula (1) relative to the electrolyte is more than 0.001 ppm by mass and less than 50,000 ppm by mass.

7. The electrolyte according to any one of claims 1 to 3, wherein, The content of the compound represented by the general formula (1) relative to the solvent is more than 10% by volume and less than 70% by volume.

8. The electrolyte according to any one of claims 1 to 3, wherein, The electrolyte comprises a compound represented by the following general formula (2): Rf 3 -O-Rf 4 (2) In equation (2), Rf 3 and Rf 4 Whether the groups are the same or different, they are alkyl groups with 1 to 10 carbon atoms, or fluoroalkyl groups with 1 to 10 carbon atoms; wherein, Rf 3 and Rf 4 At least one of them is a fluoroalkyl group.

9. An electrochemical device, characterized in that, An electrolyte having any one of claims 1 to 8.

10. A lithium-ion secondary battery, characterized in that, An electrolyte having any one of claims 1 to 8.

11. A component, characterized in that, It has the electrochemical device of claim 9 or the lithium-ion secondary battery of claim 10.

12. An additive for use in electrolytes, characterized in that, Compounds comprising the following general formula (1): Rf 1 -O-Rf 2 (1) In equation (1), Rf 1 and Rf 2 Whether the groups are the same or different, they are fluoroalkenyl groups with 2 to 4 carbon atoms.

13. The electrolyte additive according to claim 12, wherein, The compound represented by the general formula (1) is CF2=CF-O-CH2CF=CF2.

14. The electrolyte additive according to claim 12, wherein, The content of the compound represented by the general formula (1) is 0.000099% by mass or more, relative to the additive.

15. The electrolyte additive according to claim 12, wherein, The content of the compound represented by the general formula (1) is 80% by mass or more, relative to the additive.

16. The additive for electrolyte according to claim 12, wherein, The additive comprises a compound represented by the following general formula (2): Rf 3 -O-Rf 4 (2) In equation (2), Rf 3 and Rf 4 Whether the groups are the same or different, they are alkyl groups with 1 to 10 carbon atoms, or fluoroalkyl groups with 1 to 10 carbon atoms; wherein, Rf 3 and Rf 4 At least one of them is a fluoroalkyl group.

17. A solvent for use in an electrolyte, characterized in that, Compounds comprising the following general formula (1): Rf 1 -O-Rf 2 (1) In equation (1), Rf 1 and Rf 2 Whether the groups are the same or different, they are fluoroalkenyl groups with 2 to 4 carbon atoms.

18. The solvent for the electrolyte according to claim 17, wherein, The compound represented by the general formula (1) is CF2=CF-O-CH2CF=CF2.

19. The solvent for the electrolyte according to claim 17, wherein, The content of the compound represented by the general formula (1) relative to the solvent is more than 10% by volume and less than 70% by volume.

20. The solvent for an electrolyte according to claim 17, wherein, The solvent comprises a compound represented by the following general formula (2): Rf 3 -O-Rf 4 (2) In equation (2), Rf 3 and Rf 4 Whether the groups are the same or different, they are alkyl groups with 1 to 10 carbon atoms, or fluoroalkyl groups with 1 to 10 carbon atoms; wherein, Rf 3 and Rf 4 At least one of them is a fluoroalkyl group.

Images