Battery, method for manufacturing battery, and vehicle

Abstract

To provide a battery in which cycle characteristics when a metal material is used as an active material of a negative electrode, especially swelling of the battery when charge and discharge are repeated is improved.SOLUTION: A battery comprising a positive electrode, a negative electrode, and an electrolytic solution, wherein the negative electrode comprises a metal material as an active material and a carbon nanotube, the electrolytic solution comprises an electrolyte, a non-aqueous solvent, and a specific compound, and the specific compound comprises, for example, a compound (A) represented by the following general formula (A): (In General Formula (A), MAm + is an m-valent cation, RA1 is a fluoride atom or an alkoxy group, and Am is an integer of 1 to 2.). ) SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a battery, a battery manufacturing method, and a vehicle. [Background technology]

[0002] Non-aqueous electrolyte batteries such as lithium ion secondary batteries have been put to practical use in a wide range of applications, such as power sources for so-called small consumer devices such as mobile phones such as smartphones and laptop computers, and on-board power sources for driving electric vehicles, etc. Therefore, numerous studies have been conducted in the fields of positive and negative electrode active materials and non-aqueous electrolyte additives as means for improving the battery characteristics of non-aqueous electrolyte batteries.

[0003] Graphite is widely used as the negative electrode active material in lithium-ion secondary batteries. In recent years, however, efforts to increase the capacity of lithium-ion secondary batteries have been accelerating, and the introduction of high-capacity active materials (e.g., Si-based active materials) that have a large theoretical capacity per mass of electrode active material is being considered. Compared to graphite, Si-based active materials have issues such as performance degradation, such as a decrease in capacity and an increase in resistance during repeated charging and discharging.

[0004] In response to this, various studies have been conducted to prevent the deterioration of Si-based active materials, and although the issues are being resolved, further improvements are required for full-scale practical use of Si-based active materials.

[0005] Therefore, active studies have been conducted to improve the electrolyte and the negative electrode. For example, Patent Document 1 discloses a study to improve the capacity of a lithium ion secondary battery during large current discharge by using a negative electrode that combines graphite, an Si-carbon composite material, and carbon nanotubes. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2022-81460 Summary of the Invention [Problem to be solved by the invention]

[0007] However, to achieve dramatic improvements toward practical application of metal materials such as Si-based active materials as negative electrode active materials, it is necessary to consider the electrolyte and the negative electrode in a coordinated manner. For example, in the lithium-ion secondary battery described in Patent Document 1, sufficient consideration was not given to the electrolyte, and there was room for further improvement in the characteristics.

[0008] An object of the present invention is to provide a battery that has improved cycle characteristics when a metal material is used as the active material of the negative electrode, and in particular, has improved swelling of the battery when repeatedly charged and discharged. [Means for solving the problem]

[0009] As a result of intensive research to solve the above problems, the inventors discovered that the cycle characteristics of a battery can be suitably improved by combining a negative electrode containing a metal material as an active material and carbon nanotubes with an electrolyte solution containing a specific compound, and thus completed the present invention.

[0010] That is, the gist of the present invention lies in the following. [1] A battery comprising a positive electrode, a negative electrode, and an electrolyte, the negative electrode contains a metal material and carbon nanotubes as active materials, the electrolytic solution contains an electrolyte, a non-aqueous solvent, and a specific compound; The specific compound is at least one compound selected from the group consisting of a compound (A) represented by the following general formula (A): a difluorophosphate anion-containing compound (B): a compound (C1) represented by the following general formula (C1): a compound (C2) represented by the following general formula (C2): an isocyanate compound (D): a compound (E) represented by the following general formula (E): a compound (F) represented by the following general formula (F): a compound (G) represented by the following general formula (G): and a compound (H) containing an anion represented by the following general formula (H):

[0011] [ka]

[0012] (In general formula (A), M A m+ is an m-valent cation, and R A1 is a fluorine atom or an alkoxy group, and Am is an integer of 1 to 2.

[0013] [ka]

[0014] (In general formula (C1), M C m+ is an m-valent cation, and X C1 and X C2 are each independently a halogen atom, and k C is an integer of 0 to 3, Cm is an integer of 1 to 2, and Cn is an integer of 0 to 2.

[0015] [ka]

[0016] (In general formula (C2), R C1 ~R C3 are each independently a hydrocarbon group having 1 to 10 carbon atoms which may have a substituent, or a trialkylsilyl group.

[0017] [ka]

[0018] (In general formula (E), R E1 ~R E3 are each independently a hydrocarbon group having 1 to 10 carbon atoms which may have a substituent, and R E1 ~R E3 At least one of the groups is a hydrocarbon group having a carbon-carbon unsaturated bond.

[0019] [ka]

[0020] (In general formula (F), R F1 ~R F2 are each independently a hydrocarbon group having 1 to 10 carbon atoms which may have a substituent, and Fn is an integer of 1 to 3.

[0021] [ka]

[0022] (In general formula (G), R G1 is a hydrogen atom, a halogen atom, or a monovalent hydrocarbon group which may have a substituent, and R G2 represents a hydrogen atom, an optionally substituted monovalent hydrocarbon group, or an optionally substituted alkoxy group, and X G1 is a divalent hydrocarbon group which may have a substituent, and Gn 1 is an integer between 1 and 3, and Gp 1 is an integer between 0 and 2, and Gq 1 is an integer between 1 and 3, and Gp 1 and Gq 1 The sum of is 2 or 3, and Gp 1 R G1 and Gq 1 X's G1 Two of A may be bonded to each other to form a ring; G1 is a divalent or trivalent atomic group represented by the following general formula (G1), or a trivalent atomic group represented by the following general formula (G2):

[0023] [ka]

[0024] (In general formula (G1), Z G1 is a carbon atom, a sulfur atom, a phosphorus atom, or a boron atom, and Y G101 is an oxygen atom or a sulfur atom, and YG1 ~Y G3 are each independently a single bond, an oxygen atom, a sulfur atom, or NR G101 is a group, and R G101 is a hydrogen atom or a monovalent hydrocarbon group, and R G101 When R is a monovalent hydrocarbon group, G101 represents adjacent R G1 or X G1 may be bonded to form a ring, and Gr 1 is Z G1 is a carbon atom, Z G1 is a sulfur atom, 0, 1 or 2; Z G1 is 0 or 1 when is a phosphorus atom, Z G1 is a boron atom, it is 0, and Gr 2 is Z G1 is a carbon atom or a sulfur atom, 0, Z G1 is a phosphorus atom or a boron atom, the value is 1, and * is the R G1 or X G1 However, Z G1 is a sulfur atom, and Gr 1 is 2, and Y G1 and Y G2 Except when both are single bonds.)

[0025] [ka]

[0026] (In general formula (G2), Y G4 ~Y G6 are each independently an oxygen atom, a sulfur atom, or NR G201 and R G201 is a hydrogen atom or a monovalent hydrocarbon group, and * is R G1 or X G1 )

[0027] [ka]

[0028] (In general formula (H), X H is a sulfur atom or a phosphorus atom, Hm is 1 or 2, and R H1 ~R H4 are each independently a fluorine atom, an alkyl group having 1 to 4 carbon atoms, a halogenated alkyl group having 1 to 4 carbon atoms, or a hydroxy group, provided that X H If is a sulfur atom, Hm is 2, and R H4 does not exist, and X H If is a phosphorus atom, Hm is 1.)

[0029] [2] A battery comprising a positive electrode, a negative electrode, and an electrolyte, the negative electrode contains a metal material and carbon nanotubes as active materials, the electrolytic solution contains an electrolyte, a non-aqueous solvent, and a specific compound; The specific compound includes a compound (I) represented by the following general formula (I): The battery, wherein the content of the compound (I) in the electrolyte solution is 40 mass % or less.

[0030] [ka]

[0031] (In general formula (I), R I1 and R I2 are each independently a hydrocarbon group having 1 to 10 carbon atoms which may have a substituent, and R I1 and R I2 At least one of the groups is a fluorinated alkyl group.

[0032] [3] The battery according to [1] or [2], wherein the metal material contains at least one metal selected from the group consisting of Si, Sn, As, Sb, Al, Zn, and W, and at least one compound of the metal. [4] The metal material is Si, Si oxide, and SiC y O z At least one selected from the group consisting of SiC y O z The battery according to any one of [1] to [3] above, wherein y satisfies 1≦y≦10 and 0≦z≦1. [5] The battery according to any one of [1] to [4] above, wherein the content of the metal material in the active material in the negative electrode is 0.1 mass % to 50 mass %. [6] The battery according to any one of [1] to [5] above, wherein the negative electrode further contains graphite. [7] The battery according to any one of [1] to [6] above, wherein the carbon nanotubes have a diameter of 0.5 nm to 3.0 nm. [8] The battery according to any one of [1] to [7] above, wherein the carbon nanotubes include single-walled carbon nanotubes. [9] The battery according to any one of the above [1] to [8], wherein the positive electrode contains a compound represented by the following composition formula (β): Li a Ni b Co c M d O2(β) (In the composition formula (β), 0.9≦a≦1.1, 0.5≦b≦0.98, 0.01≦c≦0.2, 0.01≦d≦0.5, and b+c+d=1. M is a metal element containing at least one element selected from the group consisting of Mn, Al, Mg, Zr, Fe, Ti, and Er, and excluding Li, Ni, and Co.)

[10] The battery according to any one of [1] to [9], wherein the following relational formula (1) is satisfied when the total content of the specific compounds in the electrolyte solution is C mass % and the diameter of the carbon nanotubes is R nm: 0.0033≦C / R≦2 (1)

[11] The battery according to any one of [1] to

[10] above, wherein the following relational expression (2) is satisfied when the total content of the specific compounds in the electrolytic solution is C mass % and the average particle size of the metal material is D μm: 0.001≦C / D≦200 (2)

[12] The battery according to any one of [1] to

[11] above, wherein the average particle size of the metal material is larger than the diameter of the carbon nanotubes.

[0033]

[13] A method for manufacturing a battery, comprising the steps of housing a positive electrode and a negative electrode in a container and injecting an electrolyte into the container, the negative electrode contains a metal material as an active material and carbon nanotubes, the electrolytic solution contains an electrolyte, a non-aqueous solvent, and a specific compound; The specific compound comprises at least one compound selected from the group consisting of a compound (A) represented by the following general formula (A), a difluorophosphate anion-containing compound (B), a compound (C1) represented by the following general formula (C1), a compound (C2) represented by the following general formula (C2), an isocyanate compound (D), a compound (E) represented by the following general formula (E), a compound (F) represented by the following general formula (F), a compound (G) represented by the following general formula (G), and a compound (H) containing an anion represented by the following general formula (H):

[0034] [ka]

[0035] (In general formula (A), M A m+ is an m-valent cation, and R A1 is a fluorine atom or an alkoxy group, and Am is an integer of 1 to 2.

[0036] [ka]

[0037] (In general formula (C1), M C m+ is an m-valent cation, and X C1 and X C2 are each independently a halogen atom, and k C is an integer of 0 to 3, Cm is an integer of 1 to 2, and Cn is an integer of 0 to 2.

[0038] [ka]

[0039] (In general formula (C2), R C1 ~R C3 are each independently a hydrocarbon group having 1 to 10 carbon atoms which may have a substituent, or a trialkylsilyl group.

[0040] [ka]

[0041] (In general formula (E), R E1 ~R E3 are each independently a hydrocarbon group having 1 to 10 carbon atoms which may have a substituent, and R E1 ~R E3 At least one of the groups is a hydrocarbon group having a carbon-carbon unsaturated bond.

[0042] [ka]

[0043] (In general formula (F), R F1 ~R F2 are each independently a hydrocarbon group having 1 to 10 carbon atoms which may have a substituent, and Fn is an integer of 1 to 3.

[0044] [ka]

[0045] (In general formula (G), R G1 is a hydrogen atom, a halogen atom, or a monovalent hydrocarbon group which may have a substituent, and R G2 represents a hydrogen atom, an optionally substituted monovalent hydrocarbon group, or an optionally substituted alkoxy group, and X G1 is a divalent hydrocarbon group which may have a substituent, and Gn 1 is an integer between 1 and 3, and Gp 1is an integer between 0 and 2, and Gq 1 is an integer between 1 and 3, and Gp 1 and Gq 1 The sum of is 2 or 3, and Gp 1 R G1 and Gq 1 X's G1 Two of A may be bonded to each other to form a ring; G1 is a divalent or trivalent atomic group represented by the following general formula (G1), or a trivalent atomic group represented by the following general formula (G2):

[0046] [ka]

[0047] (In general formula (G1), Z G1 is a carbon atom, a sulfur atom, a phosphorus atom, or a boron atom, and Y G101 is an oxygen atom or a sulfur atom, and Y G1 ~Y G3 are each independently a single bond, an oxygen atom, a sulfur atom, or NR G101 is a group, and R G101 is a hydrogen atom or a monovalent hydrocarbon group, and R G101 When R is a monovalent hydrocarbon group, G101 represents adjacent R G1 or X G1 may be bonded to form a ring, and Gr 1 is Z G1 is a carbon atom, Z G1 is a sulfur atom, 0, 1 or 2; Z G1 is 0 or 1 when is a phosphorus atom, Z G1 is a boron atom, it is 0, and Gr 2 is Z G1 is a carbon atom or a sulfur atom, 0, Z G1 is a phosphorus atom or a boron atom, the value is 1, and * is the R G1 or X G1 However, Z G1 is a sulfur atom, and Gr 1is 2, and Y G1 and Y G2 Except when both are single bonds.)

[0048] [ka]

[0049] (In general formula (G2), Y G4 ~Y G6 are each independently an oxygen atom, a sulfur atom, or NR G201 and R G201 is a hydrogen atom or a monovalent hydrocarbon group, and * is R G1 or X G1 )

[0050] [ka]

[0051] (In general formula (H), X H is a sulfur atom or a phosphorus atom, Hm is 1 or 2, and R H1 ~R H4 are each independently a fluorine atom, an alkyl group having 1 to 4 carbon atoms, a halogenated alkyl group having 1 to 4 carbon atoms, or a hydroxy group, provided that X H If is a sulfur atom, Hm is 2, and R H4 does not exist, and X H If is a phosphorus atom, Hm is 1.)

[0052]

[14] A method for manufacturing a battery, comprising the steps of housing a positive electrode and a negative electrode in a container and injecting an electrolyte into the container, the negative electrode contains a metal material as an active material and carbon nanotubes, the electrolytic solution contains an electrolyte, a non-aqueous solvent, and a specific compound; The specific compound includes a compound (I) represented by the following general formula (I): The battery, wherein the content of the compound (I) in the electrolyte solution is 40 mass % or less.

[0053] [ka]

[0054] (In general formula (I), R I1 and R I2 are each independently a hydrocarbon group having 1 to 10 carbon atoms which may have a substituent, and R I1 and R I2 At least one of the groups is a fluorinated alkyl group.

[0055]

[15] A vehicle equipped with the battery according to any one of [1] to

[12] above.

[0056] For example, the gist of embodiment A of the present invention is as follows. [A1] A battery comprising a positive electrode, a negative electrode, and an electrolyte, the negative electrode contains a metal material and carbon nanotubes as active materials, The battery, wherein the electrolytic solution contains an electrolyte, a non-aqueous solvent, and a compound (A) represented by the following general formula (A):

[0057] [ka]

[0058] (In general formula (A), M A m+ is an m-valent cation, and R A1 is a fluorine atom or an alkoxy group, and Am is an integer of 1 to 2.

[0059] [A2] The battery according to [A1], wherein the metal material includes at least one metal selected from the group consisting of Si, Sn, As, Sb, Al, Zn, and W, and at least one compound of the metal. [A3] The metal material is Si, Si oxide, and SiC y O z At least one selected from the group consisting of SiC y O z The battery according to [A1] or [A2], wherein 1≦y≦10 and 0≦z≦1 are satisfied. [A4] The battery according to any one of [A1] to [A3] above, wherein the content of the metal material in the active material in the negative electrode is 0.1 mass % to 50 mass %. [A5] The battery according to any one of [A1] to [A4] above, wherein the negative electrode further contains graphite. [A6] The battery according to any one of [A1] to [A5] above, wherein the carbon nanotubes have a diameter of 0.5 nm to 3.0 nm. [A7] The battery according to any one of [A1] to [A6], wherein the carbon nanotubes include single-walled carbon nanotubes. [A8] The battery according to any one of [A1] to [A7], wherein the positive electrode contains a compound represented by the following composition formula (β): Li a Ni b Co c M d O2(β) (In the composition formula (β), 0.9≦a≦1.1, 0.5≦b≦0.98, 0.01≦c≦0.2, 0.01≦d≦0.5, and b+c+d=1. M is a metal element containing at least one element selected from the group consisting of Mn, Al, Mg, Zr, Fe, Ti, and Er, and excluding Li, Ni, and Co.) [A9] The battery according to any one of [A1] to [A8], wherein the compound (A) represented by the general formula (A) contains at least one compound selected from the group consisting of lithium fluorosulfonate, lithium methylsulfate, and lithium ethylsulfate. [A10] The content of the compound (A) represented by the general formula (A) in the electrolytic solution is C A mass%, and the diameter of the carbon nanotube is R A The battery according to any one of [A1] to [A9] above, which satisfies the following relational formula (1A) when expressed as nm: 0.0033≦C A / R A ≦2 (1A) [A11] The content of the compound (A) represented by the general formula (A) in the electrolytic solution is C A mass%, the average particle size of the metal material is D A The battery according to any one of [A1] to [A10] above, which satisfies the following relational formula (2A) when expressed in μm: 0.001≦C A / D A ≦200 (2A) [A12] The battery according to any one of [A1] to [A11] above, wherein the average particle size of the metal material is larger than the diameter of the carbon nanotubes.

[0060] [A13] A method for manufacturing a battery, comprising the steps of housing a positive electrode and a negative electrode in a container and injecting an electrolyte into the container, the negative electrode contains a metal material as an active material and carbon nanotubes, The method for producing a battery, wherein the electrolytic solution contains an electrolyte, a non-aqueous solvent, and a compound represented by the following general formula (A):

[0061] [ka]

[0062] (In general formula (A), M A m+ is an m-valent cation, and R A1 is a fluorine atom or an alkoxy group, and Am is an integer of 1 to 2.

[0063] [A14] A vehicle comprising the battery according to any one of [A1] to [A12] above.

[0064] For example, the gist of embodiment B, which is one embodiment of the present invention, is as follows. [B1] A battery comprising a positive electrode, a negative electrode, and an electrolyte, the negative electrode contains a metal material and carbon nanotubes as active materials, The battery, wherein the electrolytic solution comprises an electrolyte, a non-aqueous solvent, and a difluorophosphate anion-containing compound (B). [B2] The battery according to [B1], wherein the metal material includes at least one metal selected from the group consisting of Si, Sn, As, Sb, Al, Zn, and W, and at least one compound of the metal. [B3] The metal material is Si, Si oxide, and SiC y O z At least one selected from the group consisting of SiC y O z The battery according to [B1] or [B2], wherein 1≦y≦10 and 0≦z≦1 are satisfied. [B4] The battery according to any one of [B1] to [B3], wherein the content of the metal material in the active material in the negative electrode is 0.1 mass % to 50 mass %. [B5] The battery according to any one of [B1] to [B4], wherein the negative electrode further contains graphite. [B6] The battery according to any one of [B1] to [B5], wherein the carbon nanotubes have a diameter of 0.5 nm to 3.0 nm. [B7] The battery according to any one of [B1] to [B6], wherein the carbon nanotubes include single-walled carbon nanotubes. [B8] The battery according to any one of [B1] to [B7], wherein the positive electrode contains a compound represented by the following composition formula (β): Li a Ni b Co c M d O2(β) (In the composition formula (β), 0.9≦a≦1.1, 0.5≦b≦0.98, 0.01≦c≦0.2, 0.01≦d≦0.5, and b+c+d=1. M is a metal element containing at least one element selected from the group consisting of Mn, Al, Mg, Zr, Fe, Ti, and Er, and excluding Li, Ni, and Co.) [B9] The battery according to any one of [B1] to [B8], wherein the difluorophosphate anion-containing compound (B) contains at least one of lithium difluorophosphate and sodium difluorophosphate. [B10] The content of the difluorophosphate anion-containing compound (B) in the electrolytic solution is C B mass%, and the diameter of the carbon nanotube is R B The battery according to any one of [B1] to [B9] above, which satisfies the following relational formula (1B) when expressed as nm: 0.0033≦C B / R B ≦2 (1B) [B11] The content of the difluorophosphate anion-containing compound (B) in the electrolytic solution is C B mass%, the average particle size of the metal material is D B The battery according to any one of [B1] to [B10] above, which satisfies the following relational formula (2B) when expressed in μm: 0.001≦C B / D B ≦200 (2B) [B12] The battery according to any one of [B1] to [B11], wherein the average particle size of the metal material is larger than the diameter of the carbon nanotubes.

[0065] [B13] A method for manufacturing a battery, comprising the steps of housing a positive electrode and a negative electrode in a container and injecting an electrolyte into the container, the negative electrode contains a metal material as an active material and carbon nanotubes, The method for producing a battery, wherein the electrolytic solution contains an electrolyte, a non-aqueous solvent, and a difluorophosphate anion-containing compound (B).

[0066] [B14] A vehicle comprising the battery according to any one of [B1] to [B12].

[0067] For example, the gist of embodiment C, which is one embodiment of the present invention, is as follows. [C1] A battery comprising a positive electrode, a negative electrode, and an electrolyte, the negative electrode contains a metal material and carbon nanotubes as active materials, The battery, wherein the electrolytic solution contains an electrolyte, a non-aqueous solvent, and at least one compound (C) selected from the group consisting of a compound (C1) represented by the following general formula (C1) and a compound (C2) represented by the following general formula (C2):

[0068] [ka]

[0069] (In general formula (C1), M C m+ is an m-valent cation, and X C1 and X C2 are each independently a halogen atom, and k C is an integer of 0 to 3, Cm is an integer of 1 to 2, and Cn is an integer of 0 to 2.

[0070] [ka]

[0071] (In general formula (C2), R C1 ~R C3 are each independently a hydrocarbon group having 1 to 10 carbon atoms which may have a substituent, or a trialkylsilyl group.

[0072] [C2] The battery according to [C1], wherein the metal material includes at least one metal selected from the group consisting of Si, Sn, As, Sb, Al, Zn, and W, and at least one compound of the metal. [C3] The metal material is Si, Si oxide, and SiC y O z At least one selected from the group consisting of SiC y O z The battery according to [C1] or [C2] above, wherein y satisfies 1≦y≦10 and 0≦z≦1. [C4] The battery according to any one of [C1] to [C3] above, wherein the content of the metal material in the active material in the negative electrode is 0.1 mass % to 50 mass %. [C5] The battery according to any one of [C1] to [C4] above, wherein the negative electrode further contains graphite. [C6] The battery according to any one of [C1] to [C5] above, wherein the carbon nanotubes have a diameter of 0.5 nm to 3.0 nm. [C7] The battery according to any one of [C1] to [C6] above, wherein the carbon nanotubes include single-walled carbon nanotubes. [C8] The battery according to any one of [C1] to [C7] above, wherein the positive electrode contains a compound represented by the following composition formula (β): Li a Ni b Co c M d O2(β) (In the composition formula (β), 0.9≦a≦1.1, 0.5≦b≦0.98, 0.01≦c≦0.2, 0.01≦d≦0.5, and b+c+d=1. M is a metal element containing at least one element selected from the group consisting of Mn, Al, Mg, Zr, Fe, Ti, and Er, and excluding Li, Ni, and Co.) [C9] The battery according to any one of [C1] to [C8] above, wherein the compound (C1) represented by the general formula (C1) is at least one compound selected from the group consisting of lithium tetrafluoroborate, lithium difluorooxalatoborate, and lithium bisoxalatoborate. [C10] The battery according to any one of [C1] to [C9] above, wherein the compound (C2) represented by the general formula (C2) is at least one compound selected from the group consisting of trimethyl borate, triethyl borate, tris(2,2,2-trifluoroethyl)borate, tributyl borate, tris(trimethylsilyl)borate, and triethanolamine borate. [C11] The battery according to any one of [C1] to [C10] above, wherein the total content of the compound (C) in the electrolytic solution is 0.001 mass % to 0.7 mass %. [C12] The total content of the compound (C) in the electrolyte solution is C C mass%, and the diameter of the carbon nanotube is RC The battery according to any one of [C1] to [C11] above, which satisfies the following relational formula (1C) when expressed as nm: 0.0033≦C C / R C ≦2 (1C) [C13] The total content of the compound (C) in the electrolyte solution is C C mass%, the average particle size of the metal material is D C The battery according to any one of [C1] to [C12] above, which satisfies the following relational formula (2C) when expressed in μm: 0.001≦C C / D C ≦200 (2C) [C14] The battery according to any one of [C1] to [C13] above, wherein the average particle size of the metal material is larger than the diameter of the carbon nanotubes.

[0073] [C15] A method for manufacturing a battery, comprising the steps of housing a positive electrode and a negative electrode in a container and injecting an electrolyte into the container, the negative electrode contains a metal material as an active material and carbon nanotubes, A method for producing a battery, wherein the electrolytic solution contains an electrolyte, a non-aqueous solvent, and at least one compound (C) selected from the group consisting of a compound (C1) represented by the following general formula (C1) and a compound (C2) represented by the following general formula (C2):

[0074] [ka]

[0075] (In general formula (C1), M C m+ is an m-valent cation, and X C1 and X C2 are each independently a halogen atom, and k C is an integer of 0 to 3, Cm is an integer of 1 to 2, and Cn is an integer of 0 to 2.

[0076] [ka]

[0077] (In general formula (C2), R C1 ~R C3 are each independently a hydrocarbon group having 1 to 10 carbon atoms which may have a substituent, or a trialkylsilyl group.

[0078] [C16] A vehicle comprising the battery according to any one of [C1] to [C14] above.

[0079] For example, the gist of embodiment D, which is one embodiment of the present invention, is as follows. [D1] A battery comprising a positive electrode, a negative electrode, and an electrolyte, the negative electrode contains a metal material and carbon nanotubes as active materials, The battery according to [D1], wherein the electrolytic solution contains an electrolyte, a non-aqueous solvent, and an isocyanate compound (D). [D2] The battery according to [D1], wherein the metal material contains at least one metal selected from the group consisting of Si, Sn, As, Sb, Al, Zn, and W, and at least one compound of the metal. [D3] The metal material is Si, Si oxide, and SiC y O z At least one selected from the group consisting of SiC y O z The battery according to [D1] or [D2], wherein 1≦y≦10 and 0≦z≦1 are satisfied. [D4] The battery according to any one of [D1] to [D3] above, wherein the content of the metal material in the active material in the negative electrode is 0.1 mass % to 50 mass %. [D5] The battery according to any one of [D1] to [D4], wherein the negative electrode further contains graphite. [D6] The battery according to any one of [D1] to [D5], wherein the carbon nanotubes have a diameter of 0.5 nm to 3.0 nm. [D7] The battery according to any one of [D1] to [D6], wherein the carbon nanotubes include single-walled carbon nanotubes. [D8] The battery according to any one of [D1] to [D7], wherein the positive electrode contains a compound represented by the following composition formula (β): Li a Ni b Co c M d O2(β) (In the composition formula (β), 0.9≦a≦1.1, 0.5≦b≦0.98, 0.01≦c≦0.2, 0.01≦d≦0.5, and b+c+d=1. M is a metal element containing at least one element selected from the group consisting of Mn, Al, Mg, Zr, Fe, Ti, and Er, and excluding Li, Ni, and Co.) [D9] The battery according to any one of [D1] to [D8], wherein the isocyanate compound (D) includes a compound (D1) represented by the following general formula (D1):

[0080] [ka]

[0081] (In general formula (D1), X D is a hydrocarbon group having 1 to 20 carbon atoms, and Z D is a hydrogen atom or an isocyanato group.

[0082] [D10] The content of the isocyanate compound (D) in the electrolytic solution is C D mass%, and the diameter of the carbon nanotube is R D The battery according to any one of [D1] to [D9] above, which satisfies the following relational formula (1D) when expressed as nm: 0.0033≦C D / R D ≦2 (1D) [D11] The content of the isocyanate compound (D) in the electrolytic solution is C D mass%, the average particle size of the metal material is D D The battery according to any one of [D1] to [D10] above, which satisfies the following relational formula (2D) when expressed in μm: 0.001≦C D / D D ≦200 (2D) [D12] The battery according to any one of [D1] to [D11], wherein the average particle size of the metal material is larger than the diameter of the carbon nanotubes.

[0083] [D13] A method for manufacturing a battery, comprising the steps of housing a positive electrode and a negative electrode in a container and injecting an electrolyte into the container, the negative electrode contains a metal material as an active material and carbon nanotubes, The method for producing a battery, wherein the electrolytic solution contains an electrolyte, a non-aqueous solvent, and an isocyanate compound (D).

[0084] [D14] A vehicle comprising the battery according to any one of [D1] to [D12] above.

[0085] For example, the gist of aspect E, which is one embodiment of the present invention, is as follows. [E1] A battery comprising a positive electrode, a negative electrode, and an electrolyte, the negative electrode contains a metal material and carbon nanotubes as active materials, The battery, wherein the electrolytic solution contains an electrolyte, a non-aqueous solvent, and a compound (E) represented by the following general formula (E):

[0086] [ka]

[0087] (In general formula (E), R E1 ~R E3 are each independently a hydrocarbon group having 1 to 10 carbon atoms which may have a substituent, and R E1 ~R E3 At least one of the groups is a hydrocarbon group having a carbon-carbon unsaturated bond.

[0088] [E2] The battery according to [E1], wherein the metal material includes at least one metal selected from the group consisting of Si, Sn, As, Sb, Al, Zn, and W, and at least one compound of the metal. [E3] The metal material is Si, Si oxide, and SiC y O z At least one selected from the group consisting of SiC y O z The battery according to [E1] or [E2], wherein 1≦y≦10 and 0≦z≦1 are satisfied. [E4] The battery according to any one of [E1] to [E3] above, wherein the content of the metal material in the active material in the negative electrode is 0.1 mass % to 50 mass %. [E5] The battery according to any one of [E1] to [E4] above, wherein the negative electrode further contains graphite. [E6] The battery according to any one of [E1] to [E5] above, wherein the carbon nanotubes have a diameter of 0.5 nm to 3.0 nm. [E7] The battery according to any one of [E1] to [E6] above, wherein the carbon nanotubes include single-walled carbon nanotubes. [E8] The battery according to any one of [E1] to [E7] above, wherein the positive electrode contains a compound represented by the following composition formula (β): Li a Ni b Co c M d O2(β) (In the composition formula (β), 0.9≦a≦1.1, 0.5≦b≦0.98, 0.01≦c≦0.2, 0.01≦d≦0.5, and b+c+d=1. M is a metal element containing at least one element selected from the group consisting of Mn, Al, Mg, Zr, Fe, Ti, and Er, and excluding Li, Ni, and Co.) [E9] R in the general formula (E) E1 ~R E3 are each independently a hydrocarbon group having a carbon-carbon unsaturated bond, and R E1 ~R E3 The battery according to any one of [E1] to [E8] above, wherein at least one of the groups is an allyl group or a methallyl group. [E10] The content of the compound (E) represented by the general formula (E) in the electrolytic solution is C E mass%, and the diameter of the carbon nanotube is RE The battery according to any one of [E1] to [E9] above, which satisfies the following relational formula (1E) when expressed as nm: 0.0033≦C E / R E ≦2 (1E) [E11] The content of the compound (E) represented by the general formula (E) in the electrolytic solution is C E mass%, the average particle size of the metal material is D E The battery according to any one of [E1] to [E10] above, which satisfies the following relational formula (2E) when expressed in μm: 0.001≦C E / D E ≦200 (2E) [E12] The battery according to any one of [E1] to [E11] above, wherein the average particle size of the metal material is larger than the diameter of the carbon nanotubes.

[0089] [E13] A method for manufacturing a battery, comprising the steps of housing a positive electrode and a negative electrode in a container and injecting an electrolyte into the container, the negative electrode contains a metal material as an active material and carbon nanotubes, The method for producing a battery, wherein the electrolytic solution contains an electrolyte, a non-aqueous solvent, and a compound (E) represented by the following general formula (E):

[0090] [ka]

[0091] (In general formula (E), R E1 ~R E3 are each independently a hydrocarbon group having 1 to 10 carbon atoms which may have a substituent, and R E1 ~R E3 At least one of the groups is a hydrocarbon group having a carbon-carbon unsaturated bond.

[0092] [E14] A vehicle comprising the battery according to any one of [E1] to [E12] above.

[0093] For example, the gist of aspect F, which is one embodiment of the present invention, is as follows. [F1] A battery comprising a positive electrode, a negative electrode, and an electrolyte, the negative electrode contains a metal material and carbon nanotubes as active materials, The battery, wherein the electrolytic solution contains an electrolyte, a non-aqueous solvent, and a compound (F) represented by the following general formula (F):

[0094] [ka]

[0095] (In general formula (F), R F1 ~R F2 are each independently a hydrocarbon group having 1 to 10 carbon atoms which may have a substituent, and Fn is an integer of 1 to 3.

[0096] [F2] The battery according to [F1], wherein the metal material includes at least one metal selected from the group consisting of Si, Sn, As, Sb, Al, Zn, and W, and at least one compound of the metal. [F3] The metal material is Si, Si oxide, and SiC y O z At least one selected from the group consisting of SiC y O z The battery according to [F1] or [F2], wherein 1≦y≦10 and 0≦z≦1 are satisfied. [F4] The battery according to any one of [F1] to [F3] above, wherein the content of the metal material in the active material in the negative electrode is 0.1 mass % to 50 mass %. [F5] The battery according to any one of [F1] to [F4], wherein the negative electrode further contains graphite. [F6] The battery according to any one of [F1] to [F5] above, wherein the carbon nanotubes have a diameter of 0.5 nm to 3.0 nm. [F7] The battery according to any one of [F1] to [F6], wherein the carbon nanotubes include single-walled carbon nanotubes. [F8] The battery according to any one of [F1] to [F7], wherein the positive electrode contains a compound represented by the following composition formula (β): Li a Ni b Co c M d O2(β) (In the composition formula (β), 0.9≦a≦1.1, 0.5≦b≦0.98, 0.01≦c≦0.2, 0.01≦d≦0.5, and b+c+d=1. M is a metal element containing at least one element selected from the group consisting of Mn, Al, Mg, Zr, Fe, Ti, and Er, and excluding Li, Ni, and Co.) [F9] The content of the compound (F) represented by the general formula (F) in the electrolytic solution is C F mass%, and the diameter of the carbon nanotube is R F The battery according to any one of [F1] to [F8] above, which satisfies the following relational formula (1F) when expressed as nm: 0.0033≦C F / R F ≦2 (1F) [F10] The content of the compound (F) represented by the general formula (F) in the electrolytic solution is C F mass%, the average particle size of the metal material is D F The battery according to any one of [F1] to [F9] above, which satisfies the following relational formula (2F) when expressed in μm: 0.001≦C F / D F ≦200 (2F) [F11] The battery according to any one of [F1] to [F10], wherein the average particle size of the metal material is larger than the diameter of the carbon nanotubes.

[0097] [F12] A method for manufacturing a battery, comprising the steps of housing a positive electrode and a negative electrode in a container and injecting an electrolyte into the container, the negative electrode contains a metal material as an active material and carbon nanotubes, The method for producing a battery, wherein the electrolytic solution contains an electrolyte, a non-aqueous solvent, and a compound (F) represented by the following general formula (F):

[0098] [ka]

[0099] (In general formula (F), R F1 ~R F2 are each independently a hydrocarbon group having 1 to 10 carbon atoms which may have a substituent, and Fn is an integer of 1 to 3.

[0100] [F13] A vehicle comprising the battery according to any one of [F1] to [F11].

[0101] For example, the gist of aspect G, which is one embodiment of the present invention, is as follows. [G1] A battery comprising a positive electrode, a negative electrode, and an electrolyte, the negative electrode contains a metal material and carbon nanotubes as active materials, The battery, wherein the electrolytic solution contains an electrolyte, a non-aqueous solvent, and a compound (G) represented by the following general formula (G):

[0102] [ka]

[0103] (In general formula (G), R G1 is a hydrogen atom, a halogen atom, or a monovalent hydrocarbon group which may have a substituent, and R G2 represents a hydrogen atom, an optionally substituted monovalent hydrocarbon group, or an optionally substituted alkoxy group, and X G1 is a divalent hydrocarbon group which may have a substituent, and Gn 1 is an integer between 1 and 3, and Gp 1 is an integer between 0 and 2, and Gq 1 is an integer between 1 and 3, and Gp 1 and Gq 1 The sum of is 2 or 3, and Gp 1 R G1 and Gq 1 X's G1 Two of A may be bonded to each other to form a ring;G1 is a divalent or trivalent atomic group represented by the following general formula (G1), or a trivalent atomic group represented by the following general formula (G2):

[0104] [ka]

[0105] (In general formula (G1), Z G1 is a carbon atom, a sulfur atom, a phosphorus atom, or a boron atom, and Y G101 is an oxygen atom or a sulfur atom, and Y G1 ~Y G3 are each independently a single bond, an oxygen atom, a sulfur atom, or NR G101 is a group, and R G101 is a hydrogen atom or a monovalent hydrocarbon group, and R G101 When R is a monovalent hydrocarbon group, G101 represents adjacent R G1 or X G1 may be bonded to form a ring, and Gr 1 is Z G1 is a carbon atom, Z G1 is a sulfur atom, 0, 1 or 2; Z G1 is 0 or 1 when is a phosphorus atom, Z G1 is a boron atom, it is 0, and Gr 2 is Z G1 is a carbon atom or a sulfur atom, 0, Z G1 is a phosphorus atom or a boron atom, the value is 1, and * is the R G1 or X G1 However, Z G1 is a sulfur atom, and Gr 1 is 2, and Y G1 and Y G2 Except when both are single bonds.)

[0106] [ka]

[0107] (In general formula (G2), Y G4 ~Y G6 are each independently an oxygen atom, a sulfur atom, or NR G201 is a group, and R G201 is a hydrogen atom or a monovalent hydrocarbon group, and * is R G1 or X G1 )

[0108] [G2] The battery according to [G1], wherein the metal material includes at least one metal selected from the group consisting of Si, Sn, As, Sb, Al, Zn, and W, and at least one compound of the metal. [G3] The metal material is Si, Si oxide, and SiC y O z At least one selected from the group consisting of SiC y O z The battery according to [G1] or [G2], wherein 1≦y≦10 and 0≦z≦1 are satisfied. [G4] The battery according to any one of [G1] to [G3] above, wherein the content of the metal material in the active material in the negative electrode is 0.1 mass % to 50 mass %. [G5] The battery according to any one of [G1] to [G4] above, wherein the negative electrode further contains graphite. [G6] The battery according to any one of [G1] to [G5] above, wherein the carbon nanotubes have a diameter of 0.5 nm to 3.0 nm. [G7] The battery according to any one of [G1] to [G6], wherein the carbon nanotubes include single-walled carbon nanotubes. [G8] The battery according to any one of [G1] to [G7], wherein the positive electrode contains a compound represented by the following composition formula (β): Li a Ni b Co c M d O2(β) (In the composition formula (β), 0.9≦a≦1.1, 0.5≦b≦0.98, 0.01≦c≦0.2, 0.01≦d≦0.5, and b+c+d=1. M is a metal element containing at least one element selected from the group consisting of Mn, Al, Mg, Zr, Fe, Ti, and Er, and excluding Li, Ni, and Co.) [G9] The content of the compound (G) represented by the general formula (G) in the electrolytic solution is C G mass%, and the diameter of the carbon nanotube is R G The battery according to any one of [G1] to [G8] above, which satisfies the following relational formula (1G) when expressed as nm: 0.0033≦C G / R G ≦2 (1G) [G10] The content of the compound (G) represented by the general formula (G) in the electrolytic solution is C G mass%, the average particle size of the metal material is D G The battery according to any one of [G1] to [G9] above, which satisfies the following relational formula (2G) when expressed in μm: 0.001≦C G / D G ≦200 (2G) [G11] The battery according to any one of [G1] to [G10], wherein the average particle size of the metal material is larger than the diameter of the carbon nanotubes.

[0109] [G12] A method for manufacturing a battery, comprising the steps of housing a positive electrode and a negative electrode in a container and injecting an electrolyte into the container, the negative electrode contains a metal material as an active material and carbon nanotubes, The method for producing a battery, wherein the electrolytic solution contains an electrolyte, a non-aqueous solvent, and a compound (G) represented by the following general formula (G):

[0110] [ka]

[0111] (In general formula (G), R G1is a hydrogen atom, a halogen atom, or a monovalent hydrocarbon group which may have a substituent, and R G2 represents a hydrogen atom, an optionally substituted monovalent hydrocarbon group, or an optionally substituted alkoxy group, and X G1 is a divalent hydrocarbon group which may have a substituent, and Gn 1 is an integer between 1 and 3, and Gp 1 is an integer between 0 and 2, and Gq 1 is an integer between 1 and 3, and Gp 1 and Gq 1 The sum of is 2 or 3, and Gp 1 R G1 and Gq 1 X's G1 Two of A may be bonded to each other to form a ring; G1 is a divalent or trivalent atomic group represented by the following general formula (G1), or a trivalent atomic group represented by the following general formula (G2):

[0112] [ka]

[0113] (In general formula (G1), Z G1 is a carbon atom, a sulfur atom, a phosphorus atom, or a boron atom, and Y G101 is an oxygen atom or a sulfur atom, and Y G1 ~Y G3 are each independently a single bond, an oxygen atom, a sulfur atom, or NR G101 is a group, and R G101 is a hydrogen atom or a monovalent hydrocarbon group, and R G101 When R is a monovalent hydrocarbon group, G101 represents adjacent R G1 or X G1 may be bonded to form a ring, and Gr 1 is Z G1 is a carbon atom, Z G1 is a sulfur atom, 0, 1 or 2; Z G1 is 0 or 1 when is a phosphorus atom, Z G1 is a boron atom, it is 0, and Gr2 is Z G1 is a carbon atom or a sulfur atom, 0, Z G1 is a phosphorus atom or a boron atom, the value is 1, and * is the R G1 or X G1 However, Z G1 is a sulfur atom, and Gr 1 is 2, and Y G1 and Y G2 Except when both are single bonds.)

[0114] [ka]

[0115] (In general formula (G2), Y G4 ~Y G6 are each independently an oxygen atom, a sulfur atom, or NR G201 is a group, and R G201 is a hydrogen atom or a monovalent hydrocarbon group, and * is R G1 or X G1 )

[0116] [G13] A vehicle comprising the battery according to any one of [G1] to [G11].

[0117] For example, the gist of embodiment H of the present invention is as follows. [H1] A battery comprising a positive electrode, a negative electrode, and an electrolyte, the negative electrode contains a metal material and carbon nanotubes as active materials, The battery, wherein the electrolytic solution contains an electrolyte, a non-aqueous solvent, and a compound (H) containing an anion represented by the following general formula (H):

[0118] [ka]

[0119] (In general formula (H), X His a sulfur atom or a phosphorus atom, Hm is 1 or 2, and R H1 ~R H4 are each independently a fluorine atom, an alkyl group having 1 to 4 carbon atoms, a halogenated alkyl group having 1 to 4 carbon atoms, or a hydroxy group, provided that X H If is a sulfur atom, Hm is 2, and R H4 does not exist, and X H If is a phosphorus atom, Hm is 1.)

[0120] [H2] The battery according to [H1], wherein the metal material includes at least one metal selected from the group consisting of Si, Sn, As, Sb, Al, Zn, and W, and at least one compound of the metal. [H3] The metal material is Si, Si oxide, and SiC y O z At least one selected from the group consisting of SiC y O z The battery according to [H1] or [H2], wherein 1≦y≦10 and 0≦z≦1 are satisfied. [H4] The battery according to any one of [H1] to [H3] above, wherein the content of the metal material in the active material in the negative electrode is 0.1 mass % to 50 mass %. [H5] The battery according to any one of [H1] to [H4] above, wherein the negative electrode further contains graphite. [H6] The battery according to any one of [H1] to [H5] above, wherein the carbon nanotubes have a diameter of 0.5 nm to 3.0 nm. [H7] The battery according to any one of [H1] to [H6], wherein the carbon nanotubes include single-walled carbon nanotubes. [H8] The battery according to any one of [H1] to [H7], wherein the positive electrode contains a compound represented by the following composition formula (β): Li a Ni b Co c M d O2(β) (In the composition formula (β), 0.9≦a≦1.1, 0.5≦b≦0.98, 0.01≦c≦0.2, 0.01≦d≦0.5, and b+c+d=1. M is a metal element containing at least one element selected from the group consisting of Mn, Al, Mg, Zr, Fe, Ti, and Er, and excluding Li, Ni, and Co.) [H9] The content of the compound (H) containing the anion represented by the general formula (H) in the electrolyte solution is C H mass%, and the diameter of the carbon nanotube is R H The battery according to any one of [H1] to [H8] above, which satisfies the following relational formula (1H) when expressed as nm: 0.0033≦C H / R H ≦2 (1H) [H10] The content of the compound (H) containing the anion represented by the general formula (H) in the electrolytic solution is C H mass%, the average particle size of the metal material is D H The battery according to any one of [H1] to [H9] above, which satisfies the following relational formula (2H) when expressed in μm: 0.001≦C H / D H ≦200 (2H) [H11] The battery according to any one of [H1] to [H10], wherein the average particle size of the metal material is larger than the diameter of the carbon nanotubes.

[0121] [H12] A method for manufacturing a battery, comprising the steps of housing a positive electrode and a negative electrode in a container and injecting an electrolyte into the container, the negative electrode contains a metal material as an active material and carbon nanotubes, The method for producing a battery, wherein the electrolytic solution contains an electrolyte, a non-aqueous solvent, and a compound containing an anion represented by the following general formula (H):

[0122] [ka]

[0123] (In general formula (H), X His a sulfur atom or a phosphorus atom, Hm is 1 or 2, and R H1 ~R H4 are each independently a fluorine atom, an alkyl group having 1 to 4 carbon atoms, a halogenated alkyl group having 1 to 4 carbon atoms, or a hydroxy group, provided that X H If is a sulfur atom, Hm is 2, and R H4 does not exist, and X H If is a phosphorus atom, Hm is 1.)

[0124] [H13] A vehicle comprising the battery according to any one of [H1] to [H11] above.

[0125] For example, the gist of one embodiment of the present invention, Mode I, is as follows. [I1] A battery comprising a positive electrode, a negative electrode, and an electrolyte, the negative electrode contains a metal material as an active material and carbon nanotubes, The battery, wherein the electrolytic solution contains an electrolyte, a non-aqueous solvent, and a compound (I) represented by the following general formula (I):

[0126] [ka]

[0127] (In general formula (I), R I1 and R I2 are each independently a hydrocarbon group having 1 to 10 carbon atoms which may have a substituent, and R I1 and R I2 At least one of the groups is a fluorinated alkyl group.

[0128] [I2] The battery according to [I1] above, wherein the content of the compound (I) in the electrolyte solution is 40 mass % or less. [I3] The battery according to [I1] or [I2], wherein the metal material contains at least one metal selected from the group consisting of Si, Sn, As, Sb, Al, Zn, and W, and at least one compound of the metal. [I4] The metal material is Si, Si oxide, and SiCy O z At least one selected from the group consisting of SiC y O z The battery according to any one of [I1] to [I3] above, wherein 1≦y≦10 and 0≦z≦1 are satisfied. [I5] The battery according to any one of [I1] to [I4] above, wherein the content of the metal material in the active material in the negative electrode is 0.1 mass % to 50 mass %. [I6] The battery according to any one of [I1] to [I5] above, wherein the negative electrode further contains graphite. [I7] The battery according to any one of [I1] to [I6] above, wherein the carbon nanotubes have a diameter of 0.5 nm to 3.0 nm. [I8] The battery according to any one of [I1] to [I7] above, wherein the carbon nanotubes include single-walled carbon nanotubes. [I9] The battery according to any one of [I1] to [I8] above, wherein the positive electrode contains a compound represented by the following composition formula (β): Li a Ni b Co c M d O2(β) (In the composition formula (β), 0.9≦a≦1.1, 0.5≦b≦0.98, 0.01≦c≦0.2, 0.01≦d≦0.5, and b+c+d=1. M is a metal element containing at least one element selected from the group consisting of Mn, Al, Mg, Zr, Fe, Ti, and Er, and excluding Li, Ni, and Co.) [I10] R in the general formula (I) I1 and R I2 are each independently a hydrocarbon group having 1 to 2 carbon atoms which may have a substituent, and R I1 and R I2 The battery according to any one of the above [I1] to [I9], wherein at least one of the above is a fluorinated alkyl group. [I11] The content of the compound (I) represented by the general formula (I) in the electrolytic solution is C I mass%, and the diameter of the carbon nanotube is R IThe battery according to any one of [I1] to [I10] above, which satisfies the following relational formula (1I) when expressed as nm: 0.0033≦C I / R I ≦2 (1I) [I12] The content of the compound represented by the general formula (I) in the electrolytic solution is C I mass%, the average particle size of the metal material is D I The battery according to any one of [I1] to [I11] above, which satisfies the following relational formula (2I) when expressed in μm: 0.001≦C I / D I ≦200 (2I) [I13] The battery according to any one of [I1] to [I12] above, wherein the average particle size of the metal material is larger than the diameter of the carbon nanotubes.

[0129] [I14] A method for manufacturing a battery, comprising the steps of housing a positive electrode and a negative electrode in a container and injecting an electrolyte into the container, the negative electrode contains a metal material as an active material and carbon nanotubes, The method for producing a battery, wherein the electrolytic solution contains an electrolyte, a non-aqueous solvent, and a compound (I) represented by the following general formula (I):

[0130] [ka]

[0131] (In general formula (I), R I1 and R I2 are each independently a hydrocarbon group having 1 to 10 carbon atoms which may have a substituent, and R I1 and R I2 At least one of the groups is a fluorinated alkyl group.

[0132] [I15] The method for producing a battery according to [I14], wherein the content of the compound (I) in the electrolyte solution is 40 mass % or less.

[0133] [I16] A vehicle equipped with the battery according to any one of [I1] to [I13]. [Effects of the Invention]

[0134] According to the present invention, a battery using a metal material as the negative electrode active material can be provided, which has favorable improvements in cycle characteristics, particularly in swelling caused by repeated charge and discharge.The present invention also provides a vehicle equipped with the battery. DETAILED DESCRIPTION OF THE INVENTION

[0135] The following describes in detail the embodiments of the present invention. However, the following description is merely an example (typical example) of the present invention, and the present invention is not limited to these examples. Furthermore, the present invention can be implemented with any modifications within the scope of the gist of the present invention. In this specification, the symbol "to" is used to mean that the numerical values ​​before and after it are included as the lower limit and upper limit. In this specification, mass % and weight %, and parts by mass and parts by weight have the same meaning.

[0136] "battery" The battery according to this embodiment includes a positive electrode, a negative electrode, and an electrolyte. The negative electrode contains a metal material as an active material and carbon nanotubes, and the electrolytic solution contains an electrolyte, a non-aqueous solvent, and a specific compound.

[0137] The specific compound includes at least one compound selected from the group consisting of compound (A) represented by general formula (A), difluorophosphate anion-containing compound (B), compound (C1) represented by general formula (C1), compound (C2) represented by general formula (C2), isocyanate compound (D), compound (E) represented by general formula (E), compound (F) represented by general formula (F), compound (G) represented by general formula (G), compound (H) containing an anion represented by general formula (H), and compound (I) represented by general formula (I). In this specification, among the above compounds, the compound (C1) and the compound (C2) may be collectively referred to as the compound (C).

[0138] The electrolyte solution in this embodiment may contain one or more of the specific compounds described above. When the specific compound contains compound (I), the content of compound (I) in the electrolyte solution is preferably 40 mass % or less. The compounds (A) to (I) will be described in detail below.

[0139] The battery according to this embodiment can favorably improve the cycle characteristics by combining the above-described negative electrode and electrolyte. Although the mechanism behind this is unclear, the inventors believe as follows. However, the present invention is not limited to the mechanism and mechanism described below.

[0140] Metallic materials, such as silicon-based active materials, have a much larger theoretical capacity per weight and per volume than carbon anodes, which are currently widely used as anode active materials, and are therefore attracting attention as next-generation anode materials. However, the volumetric changes of the above metal materials due to the absorption and desorption of lithium ions are very large—for example, the volumetric expansion rate of Si-based active materials is approximately 100 to 300%. Such volumetric changes can cause the breakdown of electron conduction paths within the electrode, pulverization of active material particles, and other deterioration of the electrode mixture and active material.

[0141] When the active material particles become pulverized through repeated charge and discharge, highly active new surfaces (dangling bonds) become exposed. Side reactions occur between these exposed surfaces and the electrolyte, causing the active material surface to deteriorate. As a result, the capacity of the active material decreases, the depth of charge of the positive and negative electrodes differs, and cycle characteristics deteriorate. Furthermore, if the electron conduction path within the electrode is broken or the reaction between the active material surface and the electrolyte occurs unevenly, the load will be concentrated on some of the active material, causing it to become deactivated and the electrode to swell.

[0142] In contrast, the battery according to this embodiment further contains carbon nanotubes in the negative electrode. This allows the carbon nanotubes to bind to the metal material, forming a network structure. As a result, the mechanical strength of the composite negative electrode is improved, and the absorption and release of Li cations into and from the metal material, which is the active material, is uniform, reducing the side reactions described above.

[0143] Furthermore, the battery according to this embodiment contains, as an electrolyte solution, a specific compound in addition to the electrolyte and non-aqueous solvent, which reacts not only with the surface of the metal active material but also with the surface of the carbon nanotubes, thereby forming a coating that effectively suppresses the above-mentioned side reactions between these surfaces and the components of the electrolyte solution.

[0144] These efforts are believed to further increase the uniformity of the reaction of the metal active material, which will contribute to improving cycle characteristics, including suppressing swelling of the battery when repeatedly charged and discharged. The above effect can be further enhanced by selecting carbon nanotubes with optimal physical properties, such as diameter and length.

[0145] <1. Electrolyte> The electrolytic solution in this embodiment contains an electrolyte, a non-aqueous solvent, and the specific compound. Each component will be described below.

[0146] [1-1A. Specific Compound: Compound (A) represented by General Formula (A)] The compound represented by general formula (A) in this embodiment (hereinafter sometimes simply referred to as "compound (A)") has the following structure: In this embodiment, one type of compound (A) may be used alone, or two or more types may be used in any ratio and combination.

[0147] [ka]

[0148] (In general formula (A), M Am+ is an m-valent cation, and R A1 is a fluorine atom or an alkoxy group, and Am is an integer of 1 to 2.

[0149] The m-valent cation is not particularly limited as long as it is a monovalent or divalent cation, and examples thereof include lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, strontium, barium, and NR A11 R A12 R A13 R A14 (In the formula, R A11 ~R A14 and each independently represent a hydrogen atom or an organic group having 1 to 12 carbon atoms. Examples include cations such as quaternary ammonium represented by the following formula: Of these, lithium cation, sodium cation and potassium cation are preferred, lithium cation and sodium cation are more preferred, and lithium cation is even more preferred.

[0150] When the m-valent cation is a quaternary ammonium, R A11 ~R A14 The organic group having 1 to 12 carbon atoms represented by the formula (I) is not particularly limited, and examples thereof include an alkyl group which may be substituted with a halogen atom, a cycloalkyl group which may be substituted with a halogen atom or an alkyl group, an aryl group which may be substituted with a halogen atom or an alkyl group, or a nitrogen-containing heterocyclic group which may have a substituent. When the substituent in the cycloalkyl group, aryl group, or nitrogen-containing heterocyclic group is an alkyl group, the number of carbon atoms of the alkyl group which is the substituent is included in the range of 1 to 12, which is the number of carbon atoms of the organic group. Examples of the substituent that the nitrogen atom-containing heterocyclic group may have include a halogen atom, an alkyl group which may be substituted with a halogen atom, an alkenyl group which may be substituted with a halogen atom, and an alkynyl group which may be substituted with a halogen atom.

[0151] Among them, the above quaternary ammonium salts are R A11 ~R A14are each preferably independently a hydrogen atom, an alkyl group, a cycloalkyl group, or a nitrogen atom-containing heterocyclic group.

[0152] In the compound (A) of this embodiment, R A1 is a fluorine atom or an alkoxy group. A1 The number of carbon atoms in the alkoxy group represented by the following formula is preferably 1 to 5. Here, the number of carbon atoms is preferably 1 or more, and is preferably 5 or less, more preferably 4 or less, and even more preferably 3 or less.

[0153] Above R A1 When is an alkoxy group, more specific examples include a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, and the like. Above R A1 As the alkyl group, a fluorine atom, a methoxy group, and an ethoxy group are more preferred.

[0154] Am is an integer of 1 to 2, that is, 1 or 2, but Am is preferably 1 from the viewpoint of the solubility of the compound. Also, when Am is 2, M A 2+ Two anion components (SO3R A1 ) - may be the same or different, but from the viewpoint of compound production, it is preferable that they are the same.

[0155] Specific examples of the compound (A) include the following. Fluorosulfonate anion-containing compounds such as lithium fluorosulfonate, sodium fluorosulfonate, potassium fluorosulfonate, rubidium fluorosulfonate, and cesium fluorosulfonate; Methylsulfate anion-containing compounds such as lithium methylsulfate, sodium methylsulfate, potassium methylsulfate, rubidium methylsulfate, and cesium methylsulfate; compounds containing ethyl sulfate anions such as lithium ethyl sulfate, sodium ethyl sulfate, potassium ethyl sulfate, rubidium ethyl sulfate, and cesium ethyl sulfate; Compounds containing n-propyl sulfate anions such as lithium n-propyl sulfate, sodium n-propyl sulfate, potassium n-propyl sulfate, rubidium n-propyl sulfate, and cesium n-propyl sulfate.

[0156] Among these, lithium fluorosulfonate, lithium methylsulfate, and lithium ethylsulfate are preferred.

[0157] In this embodiment, the blending ratio of compound (A) to the total amount of the electrolyte solution is not limited and may be any as long as it does not significantly impair the effects of the present invention, but it is preferably, for example, 0.001 to 10 mass% and used as an additive. Here, the blending ratio is, for example, 0.001 mass% or more, preferably 0.01 mass% or more, more preferably 0.1 mass% or more, and for example, 10 mass% or less, preferably 5 mass% or less, more preferably 3 mass% or less, even more preferably 2 mass% or less, particularly preferably 1 mass% or less, and most preferably 0.5 mass% or less.

[0158] The content of compound (A) relative to the total amount of the electrolyte solution in this embodiment is not particularly limited and can be any content as long as it does not significantly impair the effects of the present invention, but can be, for example, more than 0% by mass and 10% by mass or less, or 0.001 to 10% by mass. Here, the content may be more than 0% by mass, but is, for example, 0.001% by mass or more, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and for example, 10% by mass or less, preferably 5% by mass or less, more preferably 3% by mass or less, even more preferably 2% by mass or less, particularly preferably 1% by mass or less, and most preferably 0.5% by mass or less. When the content of compound (A) is within the above range, the battery is likely to exhibit a sufficient effect of improving cycle characteristics, and it is also likely to avoid situations where high-temperature storage characteristics are deteriorated, resulting in an increase in gas generation and a decrease in discharge capacity retention rate.

[0159] [1-1B. Difluorophosphate anion-containing compound (B)] The difluorophosphate anion-containing compound (B) in this embodiment is usually an acid or a salt, preferably a salt. The difluorophosphate anion-containing compound (B) may be used alone or in any combination and ratio.

[0160] The counter cation in the difluorophosphate anion-containing compound (B) is not particularly limited, but may be lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, strontium, barium, or NR B11 R B12 R B13 R B14 (In the formula, R B11 ~R B14 and each independently represent a hydrogen atom or an organic group having 1 to 12 carbon atoms. Examples include cations such as quaternary ammonium represented by the following formula: Of these, lithium cation, sodium cation and potassium cation are preferred, lithium cation and sodium cation are more preferred, and lithium cation is even more preferred.

[0161] R of the above quaternary ammonium B11 ~R B14 The organic group having 1 to 12 carbon atoms represented by the formula (I) is not particularly limited, and examples thereof include an alkyl group which may be substituted with a halogen atom, a cycloalkyl group which may be substituted with a halogen atom or an alkyl group, an aryl group which may be substituted with a halogen atom or an alkyl group, or a nitrogen-containing heterocyclic group which may have a substituent. When the substituent in the cycloalkyl group, aryl group, or nitrogen-containing heterocyclic group is an alkyl group, the number of carbon atoms of the alkyl group which is the substituent is included in the range of 1 to 12, which is the number of carbon atoms of the organic group. Examples of the substituent that the nitrogen atom-containing heterocyclic group may have include a halogen atom, an alkyl group which may be substituted with a halogen atom, an alkenyl group which may be substituted with a halogen atom, and an alkynyl group which may be substituted with a halogen atom.

[0162] Among them, the above quaternary ammonium salts are R B11 ~R B14 are each preferably independently a hydrogen atom, an alkyl group, a cycloalkyl group, or a nitrogen atom-containing heterocyclic group.

[0163] Specific examples of the difluorophosphate anion-containing compound (B) in this embodiment include lithium difluorophosphate, sodium difluorophosphate, potassium difluorophosphate, etc., and at least one of lithium difluorophosphate and sodium difluorophosphate is preferred, with lithium difluorophosphate being more preferred.

[0164] In this embodiment, the blending ratio of the difluorophosphate anion-containing compound (B) to the total amount of the electrolyte solution is not limited and may be any amount as long as it does not significantly impair the effects of the present invention, but it is preferably used as an additive in an amount of, for example, 0.001 to 10% by mass. Here, the blending ratio is, for example, 0.001% by mass or more, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and for example, 10% by mass or less, preferably 5% by mass or less, more preferably 3% by mass or less, even more preferably 2% by mass or less, and particularly preferably 1% by mass or less.

[0165] The content of the difluorophosphate anion-containing compound (B) relative to the total amount of the electrolyte solution in this embodiment is not particularly limited and may be any content as long as it does not significantly impair the effects of the present invention, but can be, for example, more than 0% by mass and 10% by mass or less, or 0.001 to 8% by mass or less. Here, the content may be more than 0% by mass, but is, for example, 0.001% by mass or more, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and may be, for example, 10% by mass or less, or 8% by mass or less, preferably 5% by mass or less, more preferably 3% by mass or less, even more preferably 2% by mass or less, even more preferably 1% by mass or less, and most preferably 0.5% by mass or less. Note that when the electrolyte solution in this embodiment contains two or more difluorophosphate anion-containing compounds (B), the total amount of these compounds is taken as the content of the difluorophosphate anion-containing compound (B). When the content of the difluorophosphate anion-containing compound (B) is within the above range, the battery is likely to exhibit a sufficient effect of improving cycle characteristics, and it is also likely to avoid situations where the high-temperature storage characteristics are deteriorated, resulting in an increase in the amount of gas generated and a decrease in the discharge capacity retention rate.

[0166] [1-1C(1). Compound (C); Compound represented by general formula (C1)] The compound represented by general formula (C1) in this embodiment (hereinafter sometimes simply referred to as "compound (C1)") has the following structure. In this embodiment, compound (C1) may be used alone or in any combination of two or more kinds in any ratio. Also, compound (C1) may be used in any combination of two or more kinds in any ratio with a compound represented by general formula (C2).

[0167] [ka]

[0168] (In general formula (C1), M C m+ is an m-valent cation, and X C1 and X C2 are each independently a halogen atom, and k C is an integer of 0 to 3, Cm is an integer of 1 to 2, and Cn is an integer of 0 to 2.

[0169] The m-valent cation is not particularly limited as long as it is a monovalent or divalent cation, and examples thereof include lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, strontium, barium, and NR C11 R C12 R C13 R C14 (In the formula, R C11 ~R C14 and each independently represent a hydrogen atom or an organic group having 1 to 12 carbon atoms. Examples include cations such as quaternary ammonium represented by the following formula: Of these, lithium cation, sodium cation and potassium cation are preferred, lithium cation and sodium cation are more preferred, and lithium cation is even more preferred.

[0170] When the m-valent cation is a quaternary ammonium, R C11 ~R C14 The organic group having 1 to 12 carbon atoms represented by the formula (I) is not particularly limited, and examples thereof include an alkyl group which may be substituted with a halogen atom, a cycloalkyl group which may be substituted with a halogen atom or an alkyl group, an aryl group which may be substituted with a halogen atom or an alkyl group, or a nitrogen-containing heterocyclic group which may have a substituent. When the substituent in the cycloalkyl group, aryl group, or nitrogen-containing heterocyclic group is an alkyl group, the number of carbon atoms of the alkyl group which is the substituent is included in the range of 1 to 12, which is the number of carbon atoms of the organic group. Examples of the substituent that the nitrogen atom-containing heterocyclic group may have include a halogen atom, an alkyl group which may be substituted with a halogen atom, an alkenyl group which may be substituted with a halogen atom, and an alkynyl group which may be substituted with a halogen atom.

[0171] Among them, the above quaternary ammonium salts are R C11 ~R C14 are each preferably independently a hydrogen atom, an alkyl group, a cycloalkyl group, or a nitrogen atom-containing heterocyclic group.

[0172] In the compound (C1) of this embodiment, X C1 , X C2 Examples of the halogen atom represented by the formula include fluorine, chlorine, bromine, and iodine, and among these, fluorine is preferred.

[0173] In the compound (C1) of this embodiment, (CH2) kC As for k C direct bond where k is 0 C methylene group where k is 1, C ethylene group, where k is 2; CA propylene group having a bond number of 3 is preferred, and among these, a direct bond is preferred.

[0174] In the compound (C1) of this embodiment, Cn is an integer of 0 to 2.

[0175] Cm is an integer of 1 to 2, that is, 1 or 2, but Cm is preferably 1 from the viewpoint of the solubility of the compound. Also, if Cm is 2, M C 2+ The two anion components bound to the may be the same or different, but from the viewpoint of compound production, it is preferable that they are the same.

[0176] Specific examples of the compound (C1) include the following. tetrafluoroborate anion-containing compounds such as lithium tetrafluoroborate, sodium tetrafluoroborate, and potassium tetrafluoroborate; difluorooxalatoborate anion-containing compounds such as lithium difluorooxalatoborate, sodium difluorooxalatoborate, and potassium difluorooxalatoborate; Bisoxalatoborate anion-containing compounds such as lithium bisoxalatoborate, sodium bisoxalatoborate, and potassium bisoxalatoborate.

[0177] Among these, it is preferable to contain at least one compound selected from the group consisting of lithium tetrafluoroborate, lithium difluorooxalatoborate, and lithium bisoxalatoborate, and it is more preferable to contain lithium tetrafluoroborate.

[0178] In this embodiment, when compound (C1) is included as compound (C) relative to the total amount of the electrolyte solution, the total blending ratio of compound (C1) relative to the total amount of the electrolyte solution is not limited and may be any as long as it does not significantly impair the effects of the present invention, but it is preferable to use it as an additive in an amount of, for example, 0.001 to 10 mass%. Here, the blending ratio is, for example, 0.001 mass% or more, preferably 0.01 mass% or more, more preferably 0.1 mass% or more, and for example, 10 mass% or less, preferably 5 mass% or less, more preferably 3 mass% or less, even more preferably 2 mass% or less, particularly preferably 1 mass% or less, and most preferably 0.5 mass% or less.

[0179] When the electrolytic solution in this embodiment contains compound (C1) as compound (C), the total content of compound (C1) relative to the total amount of the electrolytic solution is not particularly limited and can be any content as long as it does not significantly impair the effects of the present invention, but can be, for example, more than 0% by mass and 10% by mass or less, or 0.001 to 0.7% by mass. Here, the content may be more than 0% by mass, for example, 0.001% by mass or more, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and can be, for example, 10% by mass or less, or 0.7% by mass or less, preferably 0.6% by mass or less, more preferably 0.5% by mass or less. When the content of compound (C1) is within the above range, the battery is likely to exhibit a sufficient effect of improving cycle characteristics, and it is also likely to avoid situations where the high-temperature storage characteristics are deteriorated, the amount of gas generated is increased, and the discharge capacity retention rate is reduced.

[0180] [1-1C(2). Compound (C); Compound represented by general formula (C2)] The compound represented by general formula (C2) in this embodiment (hereinafter sometimes simply referred to as "compound (C2)") has the following structure. In this embodiment, compound (C2) may be used alone or in any combination of two or more kinds in any ratio. Also, compound (C2) may be used in any combination of two or more kinds in any ratio with the compound represented by general formula (A1).

[0181] [ka]

[0182] (In general formula (C2), R C1 ~R C3 are each independently a hydrocarbon group having 1 to 10 carbon atoms which may have a substituent, or a trialkylsilyl group.

[0183] In compound (C2), R C1 ~R C3 each independently represents a hydrocarbon group having 1 to 10 carbon atoms, which may have a substituent, or a trialkylsilyl group. When the hydrocarbon group has a substituent, the number of carbon atoms contained in the substituent is not included in the number of carbon atoms (1 to 10) of the hydrocarbon group.

[0184] The hydrocarbon group having 1 to 10 carbon atoms which may have a substituent means that the hydrocarbon group may have a monovalent substituent substituting a hydrogen atom therein, or a divalent substituent substituting a group containing a carbon atom (e.g., a methylene group) therein. Any of the above substituents may contain a heteroatom.

[0185] Examples of heteroatoms include oxygen atoms, sulfur atoms, nitrogen atoms, phosphorus atoms, and halogen atoms. Examples of halogen atoms include fluorine atoms, chlorine atoms, and bromine atoms, with fluorine atoms being preferred.

[0186] Examples of the monovalent substituent containing a heteroatom include a cyano group, an isocyanato group, an acyl group (-(C=O)-Rca), an acyloxy group (-O(C=O)-Rca), an alkoxycarbonyl group (-(C=O)O-Rca), a sulfonyl group (-SO2-Rca), a sulfonyloxy group (-O(SO2)-Rca), an alkoxysulfonyl group (-(SO2)-O-Rca), an alkoxysulfonyloxy group (-O-(SO2)-O-Rca), an alkoxycarbonyloxy group (-O-(C=O)-O-Rca), an ether group (-O-Rca), and a trifluoromethyl group. Rca represents an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, or an alkynyl group having 2 to 10 carbon atoms.

[0187] Among these substituents, a cyano group, an isocyanato group, an acyloxy group (-O(C=O)-Rca), and a trifluoromethyl group are preferred, an isocyanato group, an acyloxy group (-O(C=O)-Rca), and a trifluoromethyl group are more preferred, and an acyloxy group (-O(C=O)-Rca) and a trifluoromethyl group are particularly preferred. A halogen atom is also preferred, and a fluorine atom is more preferred.

[0188] Examples of the heteroatom in the divalent substituent containing a heteroatom include an oxygen atom, a sulfur atom, a nitrogen atom, and a phosphorus atom. Among these, a phosphorus atom or a nitrogen atom is preferred, and a nitrogen atom is more preferred, from the viewpoint of strengthening the interaction with the positive electrode material and / or the negative electrode material.

[0189] In addition, R C1 ~R C3 When one or more of the above is a hydrocarbon group having 1 to 10 carbon atoms and having a substituent containing a hetero atom, the lone electron pair of the hetero atom may be coordinated to the boron atom.

[0190] In compound (C2), R C1 ~R C3When is a trialkylsilyl group, the number of carbon atoms in each alkyl group is preferably 1 to 4, and more preferably 1 to 2. Here, the number of carbon atoms is preferably 1 or more, and is preferably 4 or less, and more preferably 2 or less. Furthermore, the three alkyl groups bonded to the silicon atom may be the same or different, but from the viewpoint of compound production, they are preferably the same.

[0191] Specific examples of the trialkylsilyl group include a trimethylsilyl group, a triethylsilyl group, a tripropylsilyl group, a tributylsilyl group, a triisopropylsilyl group, and a tert-butyldimethylsilyl group. Among these, a trimethylsilyl group and a triethylsilyl group are preferred from the viewpoint of less steric hindrance and favorable interaction with the positive electrode material and / or the negative electrode material.

[0192] In compound (C2), R C1 ~R C3 may be bonded to each other to form a ring. C1 ~R C3 are bonded to each other to form a ring, R C1 ~R C3 Two of these may be bonded to each other to form a ring, or R C1 ~R C3 All combinations of may be linked together.

[0193] In compound (C2), R C1 ~R C3 may be the same or different, but from the viewpoint of ease of synthesis, it is preferable that at least two are the same, and it is more preferable that all three are the same. In addition, from the viewpoint that the compound (C2) easily interacts with the positive electrode material and / or the negative electrode material in a three-dimensional manner, R C1 ~R C3 are preferably bonded to each other to form a ring, and R C1 ~R C3 More preferably, they are bonded to each other via a substituent to form a ring.

[0194] In compound (C2), R C1 ~RC3 Examples of compounds in which the groups bond to each other via a substituent to form a ring include boron-containing cyclic compounds represented by the following general formula (C'2).

[0195] [ka]

[0196] In the above general formula (C'2), R C101 ~R C103 are each independently an alkylene group having 1 to 10 carbon atoms which may have a substituent. The alkylene group has 1 to 10 carbon atoms, preferably 1 to 6, and particularly preferably 2 to 4. Here, the number of carbon atoms is 1 or more, preferably 2 or more, and 10 or less, preferably 6 or less, and more preferably 4 or less.

[0197] R C101 ~R C103 Specifically, R in compound (C2) C1 ~R C3 Examples of such alkylene groups include those obtained by removing one hydrogen atom from the alkyl groups exemplified above. R C101 ~R C103 Examples of the alkyl group include a methylene group, a methylmethylene group, an ethylmethylene group, a dimethylmethylene group, a diethylmethylene group, a methylethylene group, a dimethylene group (ethylene group), a trimethylene group (propylene group), and a tetramethylene group (butylene group). Specific examples of the substituent that may be possessed include the groups exemplified as the monovalent substituent containing a hetero atom.

[0198] In the above general formula (C'2), Y C is an atom or group containing at least a trivalent or pentavalent heteroatom, such as a phosphorus atom (P), P=O, or a nitrogen atom (N). A nitrogen atom is particularly preferred. C The lone pair of electrons may be coordinated to boron (B).

[0199] R in general formula (C'2) C101 ~R C103 may be the same or different, but from the viewpoint of ease of synthesis, it is preferable that at least two are the same, and it is more preferable that all three are the same.

[0200] Specific examples of the compound (C2) include the following.

[0201] [ka]

[0202] Preferred examples include the following compounds.

[0203] [ka]

[0204] More preferred examples include the following compounds:

[0205] [ka]

[0206] Particularly preferred are the following compounds:

[0207] [ka]

[0208] That is, it is preferable that the compound (C2) contains at least one compound selected from the group consisting of trimethyl borate, triethyl borate, tris(2,2,2-trifluoroethyl)borate, tributyl borate, tris(trimethylsilyl)borate, and triethanolamine borate.

[0209] When the electrolytic solution of this embodiment contains compound (C2) as compound (C), the total content of compound (C2) relative to the total amount of the electrolytic solution is not particularly limited and can be any content as long as it does not significantly impair the effects of the present invention, but can be, for example, more than 0% by mass and 10% by mass or less, or 0.001 to 0.7% by mass. Here, the content is, for example, 0.001% by mass or more, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and for example, 10% by mass or less, preferably 5% by mass or less, more preferably 3% by mass or less, even more preferably 2% by mass or less, still more preferably 1% by mass or less, particularly preferably 0.7% by mass or less, particularly preferably 0.6% by mass or less, and most preferably 0.5% by mass or less. When the content of compound (C2) is within the above range, the battery is likely to exhibit a sufficient effect of improving cycle characteristics, and it is also likely to avoid situations where the high-temperature storage characteristics are deteriorated, the amount of gas generated is increased, and the discharge capacity retention rate is reduced.

[0210] When the electrolytic solution of this embodiment contains both compound (C1) and compound (C2) as compound (C), the total blending ratio of compound (C1) and compound (C2) to the total amount of the electrolytic solution is not limited and may be any ratio as long as it does not significantly impair the effects of the present invention, but it is preferable to use them as an additive in an amount of, for example, 0.001 to 10 mass%. Here, the blending ratio is, for example, 0.001 mass% or more, preferably 0.01 mass% or more, more preferably 0.1 mass% or more, and for example, 10 mass% or less, preferably 5 mass% or less, more preferably 3 mass% or less, even more preferably 2 mass% or less, and particularly preferably 1 mass% or less.

[0211] When the electrolytic solution in this embodiment contains both compound (C1) and compound (C2) as compound (C), the total content of compound (C) relative to the total amount of the electrolytic solution is not particularly limited and can be any content as long as it does not significantly impair the effects of the present invention, but can be, for example, more than 0% by mass and 10% by mass or less, or 0.001 to 1% by mass, or can be 0.001 to 0.7% by mass. Here, the content may be more than 0% by mass, but is, for example, 0.001% by mass or more, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and for example, 10% by mass or less, preferably 5% by mass or less, more preferably 3% by mass or less, even more preferably 2% by mass or less, and even more preferably 1% by mass or less, and may be 0.7% by mass or less, 0.6% by mass or less, or 0.5% by mass or less. When the content of compound (C) is within the above range, the battery is likely to exhibit a sufficient effect of improving cycle characteristics, and it is also likely to avoid situations where the high-temperature storage characteristics are deteriorated, the amount of gas generated is increased, and the discharge capacity retention rate is reduced.

[0212] Furthermore, when compound (C) contains both compound (C1) and compound (C2), it is more preferable that compound (C1) contains at least one compound selected from the group consisting of lithium tetrafluoroborate, lithium difluorooxalatoborate, and lithium bisoxalatoborate, and compound (C2) contains at least one compound selected from the group consisting of trimethylborate, triethylborate, tris(2,2,2-trifluoroethyl)borate, tributylborate, tris(trimethylsilyl)borate, and triethanolamine borate.

[0213] [1-1D. Isocyanate Compounds (D)] The isocyanate compound (D) in this embodiment is not particularly limited in type as long as it is a compound having an isocyanato group in the molecule, and examples thereof include hydrocarbon monoisocyanate compounds represented by the general formula (D1) described below, hydrocarbon diisocyanate compounds, and isocyanate compounds represented by the general formula (D2) described below. The isocyanate compound (D) may be used alone or in any combination of two or more kinds in any ratio.

[0214] [1-1D(1). Isocyanate Compound (D): Compound Represented by General Formula (D1)] The isocyanate compound (D) in the present embodiment preferably includes, for example, a compound represented by the following general formula (D1) (hereinafter, sometimes simply referred to as "compound (D1)").

[0215] [ka]

[0216] (In general formula (D1), X D is a hydrocarbon group having 1 to 20 carbon atoms, and Z D is a hydrogen atom or an isocyanato group.

[0217] where Z D When Z is a hydrogen atom, the compound (D1) is a hydrocarbon monoisocyanate compound. D When X is an isocyanato group, the compound (D1) is a hydrocarbon diisocyanate compound. D The hydrocarbon group having 1 to 20 carbon atoms may have a carbon-carbon unsaturated bond.

[0218] Each of these isocyanate compounds will now be described.

[0219] [1-1D(1)-1. Hydrocarbon monoisocyanate compounds] In general formula (D1), Z D When X is a hydrogen atom, the compound (D1) is a hydrocarbon monoisocyanate compound. D is a hydrocarbon group having 1 to 20 carbon atoms, which may be a saturated or unsaturated hydrocarbon group. The hydrocarbon group may be linear, branched, or cyclic. Some of the hydrogen atoms of the hydrocarbon group may be substituted with heteroatoms, such as halogen atoms, preferably fluorine atoms.

[0220] where X D The hydrocarbon group represented by has 1 to 20 carbon atoms, preferably 2 to 10, and more preferably 4 to 6. That is, the carbon number is 1 or more, preferably 2 or more, and more preferably 4 or more, and is 20 or less, preferably 10 or less, and more preferably 6 or less.

[0221] Specific examples of hydrocarbon monoisocyanate compounds include methyl isocyanate, ethyl isocyanate, propyl isocyanate, isopropyl isocyanate, butyl isocyanate, tert-butyl isocyanate, pentyl isocyanate, hexyl isocyanate, cyclohexyl isocyanate, phenyl isocyanate, fluorophenyl isocyanate, vinyl isocyanate, allyl isocyanate, ethynyl isocyanate, and propynyl isocyanate.

[0222] [1-1D(1)-2. Hydrocarbon diisocyanate compounds] In general formula (D1), Z D When X is an isocyanato group, the compound (D1) is a hydrocarbon diisocyanate compound. D is a hydrocarbon group having 1 to 20 carbon atoms, which may be a saturated or unsaturated hydrocarbon group. The hydrocarbon group may be linear, branched, or cyclic. All or part of the hydrogen atoms of the hydrocarbon group may be substituted with heteroatoms, such as oxygen atoms and halogen atoms, including fluorine atoms, chlorine atoms, and bromine atoms, with fluorine atoms being preferred.

[0223] where X DThe hydrocarbon group represented by has 1 to 20 carbon atoms, preferably 2 to 15, and more preferably 6 to 10. That is, the carbon number is 1 or more, preferably 2 or more, and more preferably 6 or more, and is 20 or less, preferably 15 or less, and more preferably 10 or less.

[0224] Specific examples of hydrocarbon diisocyanate compounds include monomethylene diisocyanate, dimethylene diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, heptamethylene diisocyanate, octamethylene diisocyanate, nonamethylene diisocyanate, decamethylene diisocyanate, dodecamethylene diisocyanate, 1,3-diisocyanatopropane, 1,4-diisocyanate, 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, tolylene diisocyanate, 1,2-bis(isocyanatomethyl)cyclohexane, 1,3-bis(isocyanatomethyl)cyclohexane, 1,4-bis(isocyanatomethyl)cyclohexane, 1,2-diisocyanatocyclohexane, 1,3-diisocyanatocyclohexane, 1,4-diisocyanatocyclohexane, dicyclohexylmethane-1,1'-diisocyanate, dicyclohexylmethane-2,2'-diisocyanate, dicyclohexylmethane-3,3'-diisocyanate, dicyclohexylmethane-4 ,4'-diisocyanate, bicyclo[2.2.1]heptane-2,5-diylbis(methyl isocyanate), bicyclo[2.2.1]heptane-2,6-diylbis(methyl isocyanate), isophorone diisocyanate, carbonyl diisocyanate, 1,4-diisocyanatobutane-1,4-dione, 1,5-diisocyanatopentane-1,5-dione, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, etc.

[0225] [1-1(D)(2). Isocyanate compound (D): Isocyanate compound represented by general formula (D2)] The isocyanate compound (D) in this embodiment may be an isocyanate compound represented by general formula (D2) (hereinafter, sometimes referred to as "isocyanate compound (D2)"). The isocyanate compound (D2) has a -SO-NCO structure.

[0226] [ka]

[0227] (In general formula (D2), R D1 represents an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, or an alkynyl group having 2 to 10 carbon atoms, which may be substituted with a halogen atom, an aromatic hydrocarbon group having 6 to 20 carbon atoms, which may be substituted with a halogen atom, an isocyanato group, or a halogen atom, and Dn represents an integer of 0 to 1.

[0228] In general formula (D2), R D1 When is an alkyl group having 1 to 10 carbon atoms, the number of carbon atoms in the alkyl group may be 1 to 10, preferably 1 to 6. Here, the number of carbon atoms is preferably 1 or more, and is 10 or less, preferably 6 or less.

[0229] Specific examples of the alkyl group include linear or branched alkyl groups such as methyl, ethyl, n-propyl, i-propyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, and n-octyl. Other examples include alkyl groups in which all or part of the hydrogen atoms in the alkyl groups listed above have been substituted with halogen atoms, more specifically, alkyl groups substituted with fluorine atoms. Specific examples of the alkyl group include cyclic alkyl groups such as cyclopropyl, cyclopentyl, and cyclohexyl.

[0230] In general formula (D2), R D1When is an alkenyl group, the alkenyl group has 2 to 10 carbon atoms, preferably 2 to 6. Here, the number of carbon atoms is 2 or more and 10 or less, preferably 6 or less.

[0231] Specific examples of the alkenyl group include a vinyl group, an allyl group, a methallyl group, a 1-propenyl group, a butenyl group, a pentenyl group, etc. Also included are alkenyl groups in which all or part of the hydrogen atoms of the alkenyl group have been substituted with halogen atoms, more specifically, fluorine-substituted vinyl groups, allyl groups, methallyl groups, etc.

[0232] In general formula (D2), R D1 When is an alkynyl group, the alkynyl group has 2 to 10 carbon atoms, preferably 2 to 6. Here, the number of carbon atoms is 2 or more and 10 or less, preferably 6 or less.

[0233] Specific examples of the alkynyl group include an ethynyl group, a propargyl group, a 1-propynyl group, a butynyl group, a hexynyl group, etc. Further examples include alkenyl groups in which all or part of the hydrogen atoms of the alkynyl group have been substituted with halogen atoms, more specifically, fluorine-substituted ethynyl groups, propargyl groups, 1-propynyl groups, etc.

[0234] In general formula (D2), R D1 When is an aromatic hydrocarbon group, the aromatic hydrocarbon group has 6 to 20 carbon atoms, preferably 6 to 10. Here, the number of carbon atoms is preferably 6 or more, and 20 or less, preferably 10 or less.

[0235] Specific examples of the aromatic hydrocarbon group include a phenyl group, a tolyl group, a benzyl group, and a phenethyl group. Other examples include aromatic hydrocarbon groups in which all or some of the hydrogen atoms of the aromatic hydrocarbon group have been substituted with halogen atoms, more specifically, phenyl groups, tolyl groups, benzyl groups, and phenethyl groups substituted with fluorine atoms. The substitution with the fluorine atom also includes substitution with a fluoroalkyl group such as a trifluoromethyl group.

[0236] More specifically, examples of the compound (D2) include the compounds shown below: However, the present invention is not limited to the compounds shown below.

[0237] [ka]

[0238] [ka]

[0239] [ka]

[0240] As the isocyanate compound (D) in the present embodiment, the compounds shown below are preferred from the viewpoint of improving cycle characteristics and storage characteristics. Monoisocyanate compounds having a branched and / or carbon-carbon unsaturated bond, such as isopropyl isocyanate, tert-butyl isocyanate, cyclohexyl isocyanate, vinyl isocyanate, allyl isocyanate, ethynyl isocyanate, and propynyl isocyanate; Monomethylene diisocyanate, dimethylene diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, heptamethylene diisocyanate, octamethylene diisocyanate, nonamethylene diisocyanate, decamethylene diisocyanate, dodecamethylene diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane hydrocarbon diisocyanate compounds such as hexane, dicyclohexylmethane-4,4'-diisocyanate, bicyclo[2.2.1]heptane-2,5-diylbis(methyl isocyanate), bicyclo[2.2.1]heptane-2,6-diylbis(methyl isocyanate), isophorone diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, and 2,4,4-trimethylhexamethylene diisocyanate; An isocyanate compound represented by general formula (D2):

[0241] The isocyanate compound (D) in this embodiment is more preferably isopropyl isocyanate, tert-butyl isocyanate, cyclohexyl isocyanate, allyl isocyanate, hexamethylene diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, or an isocyanate compound represented by general formula (D2).

[0242] The isocyanate compound represented by general formula (D2) is more preferably the compound shown below.

[0243] [ka]

[0244] In the present embodiment, the isocyanate compound (D) is more preferably tert-butyl isocyanate, hexamethylene diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, toluenesulfonyl isocyanate, or diisocyanatosulfone, and tert-butyl isocyanate, hexamethylene diisocyanate, or 1,3-bis(isocyanatomethyl)cyclohexane is particularly preferred because it provides a good balance of battery properties. As the hydrocarbon diisocyanate compound, an isocyanate compound having a branched chain is more preferred.

[0245] The isocyanate compound (D) in this embodiment may be a trimer compound derived from a compound having at least two isocyanato groups in the molecule, or an aliphatic polyisocyanate obtained by adding a polyhydric alcohol to the trimer compound. For example, biuret, isocyanurate, adduct, and bifunctional modified polyisocyanates represented by the basic structures of the following general formulas (D3-1) to (D3-4) can be exemplified.

[0246] [ka]

[0247] (In general formulas (D3-1) to (D3-4), R D and R D ' are each independently any hydrocarbon group.

[0248] In this embodiment, the compound having at least two isocyanate groups in the molecule also includes so-called blocked isocyanates, which are blocked with a blocking agent to improve storage stability. Examples of the blocking agent include alcohols, phenols, organic amines, oximes, and lactams. More specific examples of the blocking agent include n-butanol, phenol, tributylamine, diethylethanolamine, methyl ethyl ketoxime, and ε-caprolactam.

[0249] In order to promote the reaction based on a compound having at least two isocyanato groups in the molecule and to obtain a higher effect, it is also preferable to use a metal catalyst such as dibutyltin dilaurate or an amine catalyst such as 1,8-diazabicyclo[5.4.0]undecene-7 in combination.

[0250] In this embodiment, the blending ratio of the isocyanate compound (D) to the total amount of the electrolyte solution is not limited and may be any as long as it does not significantly impair the effects of the present invention, but it is preferably, for example, 0.001 to 10 mass% and used as an additive. Here, the blending ratio is, for example, 0.001 mass% or more, preferably 0.01 mass% or more, more preferably 0.1 mass% or more, and for example, 10 mass% or less, preferably 5 mass% or less, more preferably 3 mass% or less, even more preferably 2 mass% or less, particularly preferably 1 mass% or less, and most preferably 0.5 mass% or less.

[0251] In addition, the content ratio of the isocyanate compound (D) relative to the total amount of the electrolyte solution in this embodiment is not limited and may be any as long as it does not significantly impair the effects of the present invention, but is preferably, for example, more than 0% by mass and 10% by mass or less. Here, the content ratio may be more than 0% by mass, but is, for example, 0.001% by mass or more, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and for example, 10% by mass or less, preferably 5% by mass or less, more preferably 3% by mass or less, even more preferably 2% by mass or less, particularly preferably 1% by mass or less, and most preferably 0.5% by mass or less.

[0252] In the present embodiment, the amount of the isocyanate compound (D) blended when preparing the electrolyte solution often differs from the content of the isocyanate compound (D) determined when the resulting battery is disassembled. Specifically, the content of the isocyanate compound (D) measured when the battery is disassembled after charging and discharging and the electrolyte is extracted again often significantly decreases compared to the blending ratio when the isocyanate compound (D) is contained in the electrolyte solution and actually used to fabricate the battery. Therefore, when the isocyanate compound (D) is detected even in a very small amount in the electrolyte solution extracted after disassembling the battery, the electrolyte solution is considered to be the electrolyte solution of this embodiment.

[0253] Furthermore, when a battery is actually fabricated using an electrolyte solution containing the isocyanate compound (D) of this embodiment, even if the electrolyte solution extracted after disassembling the battery contains only a small amount of the isocyanate compound (D), the isocyanate compound (D) may be present in other components of the battery. Specifically, the isocyanate compound (D) is often detected on the positive electrode, negative electrode, or separator. Therefore, when the isocyanate compound (D) is detected in one or more of the positive electrode, negative electrode, and separator, it can be assumed that the total amount of the isocyanate compound (D) contained in the electrolyte solution and other components was contained in the electrolyte solution. Under this assumption, the content of the isocyanate compound (D) is preferably within the above range.

[0254] [1-1E. Compound (E) represented by general formula (E)] The compound represented by general formula (E) in this embodiment (hereinafter sometimes simply referred to as "compound (E)") has the following structure: In this embodiment, one type of compound (E) may be used alone, or two or more types may be used in any ratio and combination.

[0255] [ka]

[0256] (In general formula (E), R E1 ~R E3 are each independently a hydrocarbon group having 1 to 10 carbon atoms which may have a substituent, and R E1 ~R E3 At least one of the groups is a hydrocarbon group having a carbon-carbon unsaturated bond.

[0257] The number of carbon atoms in the hydrocarbon group having 1 to 10 carbon atoms is preferably 1 to 6, and particularly preferably 1 to 4. Here, the number of carbon atoms is 1 or more and 10 or less, preferably 6 or less, and more preferably 4 or less. Specific examples of the hydrocarbon group include an alkyl group, an alkenyl group, an alkynyl group, and an aryl group.

[0258] R E1 ~R E3 At least one of the groups is a hydrocarbon group having a carbon-carbon unsaturated bond, and examples of the hydrocarbon group having a carbon-carbon unsaturated bond include an alkenyl group, an alkynyl group, and an aryl group.

[0259] The hydrocarbon group having a carbon-carbon unsaturated bond is R E1 ~R E3 At least one of these is sufficient, but two or more are preferred, and all three may be sufficient. Also, R E1 ~R E3may be the same or different, but it is preferable that two or more are the same, and all three may be the same.

[0260] Specific examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a tert-butyl group, an n-pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, and a decyl group. Among these, a methyl group, an ethyl group, an n-propyl group, an n-butyl group, a tert-butyl group, an n-pentyl group, and a hexyl group are preferred, a methyl group, an ethyl group, an n-propyl group, an n-butyl group, a tert-butyl group, and an n-pentyl group are more preferred, and a methyl group, an ethyl group, and an n-butyl group are particularly preferred. The above-mentioned alkyl groups are preferred because the compound represented by general formula (E) tends to be localized near the surface of the positive electrode active material and / or the negative electrode active material.

[0261] Specific examples of the alkenyl group include a vinyl group, an allyl group, a methallyl group, a 2-butenyl group, a 3-methyl-2-butenyl group, a 3-butenyl group, and a 4-pentenyl group. Among these, a vinyl group, an allyl group, a methallyl group, and a 2-butenyl group are preferred, a vinyl group, an allyl group, and a methallyl group are more preferred, and an allyl group or a methallyl group is particularly preferred. The above-mentioned alkenyl groups are preferred because the compound (E) tends to be localized near the surface of the positive electrode active material and / or the negative electrode active material.

[0262] Specific examples of the alkynyl group include an ethynyl group, a 2-propynyl group, a 2-butynyl group, a 3-butynyl group, a 4-pentynyl group, and a 5-hexynyl group. Among these, an ethynyl group, a 2-propynyl group, a 2-butynyl group, and a 3-butynyl group are preferred, a 2-propynyl group and a 3-butynyl group are more preferred, and a 2-propynyl group is particularly preferred. The above-mentioned alkynyl groups are preferred because the compound (E) tends to be localized near the surface of the positive electrode active material and / or the negative electrode active material.

[0263] Specific examples of the aryl group include a phenyl group, a tolyl group, a benzyl group, a phenethyl group, etc. Among these, a phenyl group is preferred from the viewpoint that the compound (E) tends to be localized near the surface of the positive electrode active material and / or the negative electrode active material.

[0264] The hydrocarbon group having 1 to 10 carbon atoms may have a substituent, that is, some or all of the hydrogen atoms may be substituted with other functional groups or other atoms, as long as the effects of the present invention are not impaired. Examples of other atoms include halogen atoms, more specifically fluorine atoms, chlorine atoms, and bromine atoms. Other functional groups include cyano, isocyanato, and acyl groups (-(C=O)-R Ea ), acyloxy group (-O(C=O)-R Ea ), alkoxycarbonyl group (-(C=O)OR Ea ), sulfonyl group (-SO2-R Ea ), sulfonyloxy group (-O(SO2)-R Ea ), alkoxysulfonyl group (-(SO2)-OR Ea ), alkoxysulfonyloxy group (-O-(SO2)-OR Ea ), alkoxycarbonyloxy group (-O-(C=O)-OR Ea ), ether group (-OR Ea ), trifluoromethyl group, etc. Ea represents an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, or an alkynyl group having 2 to 10 carbon atoms. Among these substituents, a cyano group, an isocyanato group, an acyloxy group (—O(C═O)—R Ea ), a halogen atom, or a trifluoromethyl group, and more preferably a cyano group, an isocyanato group, or an acyloxy group (—O(C═O)—R Ea ), a halogen atom, and particularly preferably an isocyanato group, an acyloxy group (—O(C═O)—R Ea ) As the halogen atom, a fluorine atom is more preferable.

[0265] Compounds represented by general formula (E), more specifically, for example, compounds having the following structure, can be mentioned.

[0266] [ka]

[0267] [ka]

[0268] [ka]

[0269] Preferred examples include compounds having the following structures:

[0270] [ka]

[0271] [ka]

[0272] More preferred compounds include those having the following structures:

[0273] [ka]

[0274] Particularly preferred are compounds having the following structures:

[0275] [ka]

[0276] Most preferred are compounds having the following structures:

[0277] [ka]

[0278] Among these most preferred compounds, compounds having the following structure are preferred from the viewpoint of film-forming ability.

[0279] [ka]

[0280] The method for producing the compound represented by general formula (E) is not particularly limited, and it can be produced by any known method.

[0281] In this embodiment, the amount of compound (E) relative to the total amount of the electrolyte solution is not limited and may be any amount as long as it does not significantly impair the effects of the present invention. For example, it is preferable to use it as an additive in an amount of 0.001 to 10% by mass. Here, the amount is, for example, 0.001% by mass or more, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and for example, 10% by mass or less, preferably 5% by mass or less, more preferably 3% by mass or less, even more preferably 2% by mass or less, particularly preferably 1% by mass or less, and most preferably 0.5% by mass or less. When the amount of compound (E) is within the above range, inhibition of the electrode reaction due to excessive coverage of the negative electrode surface by reduction products can be effectively prevented. Furthermore, the interaction at the electrode interface proceeds more effectively, thereby optimizing battery characteristics.

[0282] In addition, in this embodiment, the content ratio of compound (E) relative to the total amount of the electrolyte solution is not limited and may be any as long as it does not significantly impair the effects of the present invention. For example, a ratio greater than 0% by mass and less than or equal to 10% by mass is preferred. Here, the content ratio may be greater than 0% by mass, but is, for example, 0.001% by mass or more, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and is, for example, 10% by mass or less, preferably 5% by mass or less, more preferably 3% by mass or less, even more preferably 2% by mass or less, particularly preferably 1% by mass or less, and most preferably 0.5% by mass or less. When the amount of compound (E) is within the above range, inhibition of the electrode reaction due to excessive coverage of the negative electrode surface by the reduction product can be suitably prevented. Furthermore, the reaction at the electrode interface proceeds more suitably, thereby optimizing battery characteristics.

[0283] In this embodiment, the compound (E) content in the electrolyte solution is often different from the content of the compound (E) measured when the battery is actually disassembled. Specifically, the content measured when the battery is disassembled after charging and discharging and the electrolyte is extracted again is often significantly lower than the content when the compound (E) is contained in the electrolyte solution and actually used to fabricate the battery. Therefore, when a battery is disassembled and an electrolytic solution is extracted, even if only a very small amount of the compound represented by general formula (E) can be detected, the electrolytic solution is considered to fall under the category of the electrolytic solution of this embodiment.

[0284] Furthermore, when a battery is fabricated using an electrolyte solution containing compound (E) according to this embodiment, even if the electrolyte solution extracted after disassembling the battery contains only a small amount of compound (E), compound (E) may be present in other components of the battery. Specifically, compound (E) is often detected on the positive electrode, negative electrode, or separator. Therefore, when compound (E) is detected in one or more of the positive electrode, negative electrode, and separator, it can be assumed that the total amount of compound (E) contained in the electrolyte solution and other components was contained in the electrolyte. Under this assumption, the content of the compound represented by general formula (E) is preferably within the above range.

[0285] [1-1F. Compound (F) represented by general formula (F)] The compound represented by general formula (F) in this embodiment has the following structure. The compound (F) may be used alone or in any combination of two or more kinds in any ratio.

[0286] [ka]

[0287] (In general formula (F), R F1 ~R F2 are each independently a hydrocarbon group having 1 to 10 carbon atoms which may have a substituent, and Fn is an integer of 1 to 3.

[0288] R in general formula (F) F1 ~R F2 The number of carbon atoms in the hydrocarbon group represented by is 1 to 10, preferably 1 to 6. Here, the number of carbon atoms is 1 or more and 10 or less, preferably 6 or less.

[0289] The hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples of the hydrocarbon group include alkyl groups, alkenyl groups, alkynyl groups, and aryl groups.

[0290] Specific examples of the alkyl group include methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, n-pentyl, hexyl, cyclohexyl, heptyl, octyl, nonyl, and decyl groups. Among these, methyl, ethyl, n-propyl, n-butyl, tert-butyl, n-pentyl, hexyl, and cyclohexyl groups are preferred, with methyl, ethyl, n-propyl, n-butyl, tert-butyl, cyclohexyl, and n-pentyl groups being more preferred, and methyl, ethyl, n-butyl, tert-butyl, and cyclohexyl groups being particularly preferred. The alkyl groups described above are preferred because they tend to localize compound (F) near the surfaces of the positive electrode active material and / or negative electrode active material.

[0291] Specific examples of the alkenyl group include a vinyl group, an allyl group, a methallyl group, a 2-butenyl group, a 3-methyl-2-butenyl group, a 3-butenyl group, and a 4-pentenyl group. Among these, a vinyl group, an allyl group, a methallyl group, and a 2-butenyl group are preferred, a vinyl group, an allyl group, and a methallyl group are more preferred, and an allyl group and a methallyl group are particularly preferred. The above-mentioned alkenyl groups are preferred because the compound (F) tends to be localized near the surface of the positive electrode active material and / or the negative electrode active material.

[0292] Specific examples of the alkynyl group include an ethynyl group, a 2-propynyl group, a 2-butynyl group, a 3-butynyl group, a 4-pentynyl group, and a 5-hexynyl group. Among these, an ethynyl group, a 2-propynyl group, a 2-butynyl group, and a 3-butynyl group are preferred, an ethynyl group, a 2-propynyl group, and a 3-butynyl group are more preferred, and an ethynyl group and a 2-propynyl group are particularly preferred. The above-mentioned alkynyl groups are preferred because the compound represented by general formula (F) tends to be localized near the surface of the positive electrode active material and / or the negative electrode active material.

[0293] Specific examples of the aryl group include a phenyl group, a tolyl group, a benzyl group, a phenethyl group, etc. Among these, a phenyl group is preferred from the viewpoint that the compound (F) tends to be localized near the surface of the positive electrode active material and / or the negative electrode active material.

[0294] The substituents that the hydrocarbon group having 1 to 10 carbon atoms may have include a cyano group, an isocyanato group, an acyl group (—(C═O)—R Fa ), acyloxy group (-O(C=O)-R Fa ), alkoxycarbonyl group (-(C=O)OR Fa ), sulfonyl group (-SO2-R Fa ), sulfonyloxy group (-O(SO2)-R Fa ), alkoxysulfonyl group (-(SO2)-OR Fa ), alkoxysulfonyloxy group (-O-(SO2)-OR Fa ), alkoxycarbonyloxy group (-O-(C=O)-OR Fa ), ether group (-OR Fa ), functional groups such as trifluoromethyl group, and atoms such as halogen atoms. Fa represents an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, or an alkynyl group having 2 to 10 carbon atoms.

[0295] Among these substituents, a cyano group, an isocyanato group, an acyloxy group (—O(C═O)—R Fa ), sulfonyl group (-SO2-R Fa ), a trifluoromethyl group, or a halogen atom, and more preferably a cyano group, an isocyanato group, or an acyloxy group (—O(C═O)—R Fa ), sulfonyl group (-SO2-R Fa ), a halogen atom, and particularly preferably an isocyanato group, a sulfonyl group (—SO—R Fa ) and a halogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, and a nitrogen atom, and among these, a fluorine atom is more preferred.

[0296] In general formula (F), Fn is an integer of 1 to 3 and indicates the number of fluorine atoms bonded to silicon atoms in compound (F). That is, when Fn is 1, Si in the general formula (F) is Si-R FThere are three bonds and one Si-F bond. When Fn is 2, Si in the general formula (F) is Si-R F When Fn is 3, Si in the general formula (F) is Si-R F There is one Si-F bond and three Si-R bonds. F The bond is Si-R F1 Bonding and Si-R F2 It is a general term for bonding.

[0297] Fn is an integer of 1 to 3, preferably 1 or 2, and more preferably 1. Within this range, the compound represented by compound (F) can react favorably with the Si active material and the carbon nanotubes to form a composite coating.

[0298] Fn is 1 or 2, and R F1 and R F2 If there are two or three in total, there are multiple R F1 and R F2 may be the same or different.

[0299] More specific examples of compound (F) in this embodiment include the compounds shown below, but the present invention is not limited to the compounds shown below.

[0300] [ka]

[0301] [ka]

[0302] The compound (F) in this embodiment is preferably the compound shown below.

[0303] [ka]

[0304] The compound (F) in this embodiment is more preferably the compound shown below.

[0305] [ka]

[0306] In this embodiment, the compound (F) is particularly preferably the compound shown below.

[0307] [ka]

[0308] There is no particular limitation on the production method for compound (F), and it can be produced by any known method.

[0309] In this embodiment, the blending ratio of compound (F) to the total amount of the electrolyte solution is not limited and may be any as long as it does not significantly impair the effects of the present invention, but it is preferably, for example, 0.001 to 10 mass% and used as an additive. Here, the blending ratio is, for example, 0.001 mass% or more, preferably 0.01 mass% or more, more preferably 0.1 mass% or more, and for example, 10 mass% or less, preferably 5 mass% or less, more preferably 3 mass% or less, even more preferably 2 mass% or less, and particularly preferably 1 mass% or less.

[0310] In addition, the content ratio of compound (F) relative to the total amount of the electrolyte solution in this embodiment is not limited, and is any as long as it does not significantly impair the effects of the present invention, but for example, more than 0 mass% and 10 mass% or less is preferable. Here, the content ratio may be more than 0 mass%, but is, for example, 0.001 mass% or more, preferably 0.01 mass% or more, more preferably 0.1 mass% or more, and for example, 10 mass% or less, preferably 5 mass% or less, more preferably 3 mass% or less, and even more preferably 2 mass% or less. When the content of compound (F) is within the above range, it is possible to suitably prevent inhibitions such as an increase in resistance caused by excessively covering the negative electrode surface with a film containing compound (F), and the action at the electrode interface proceeds more suitably, making it possible to optimize the battery characteristics.

[0311] In this embodiment, the compound (F) content in the electrolyte solution is often different from the content of the compound (F) measured when the resulting battery is disassembled. Specifically, the content of the compound (F) measured when the battery is disassembled after charging and discharging and the electrolyte is removed again is often significantly lower than the content when the compound (F) is contained in the electrolyte solution and actually used to fabricate the battery. Therefore, when the battery is disassembled and the electrolyte solution extracted contains even a very small amount of compound (F), the electrolyte solution is considered to fall within the scope of the present embodiment.

[0312] Furthermore, when a battery is actually fabricated using an electrolyte solution containing compound (F) according to this embodiment, even if the electrolyte solution extracted after disassembling the battery contains only a small amount of compound (F), compound (F) may be present in other components of the battery. Specifically, compound (F) is often detected on the positive electrode, negative electrode, or separator. Therefore, when compound (F) is detected in one or more of the positive electrode, negative electrode, and separator, it can be assumed that the total amount of compound (F) contained in the electrolyte solution and other components was contained in the electrolyte solution. Under this assumption, the content of compound (F) is preferably within the above range.

[0313] [1-1G. Compound (G) represented by general formula (G)] The compound represented by general formula (G) in this embodiment (hereinafter sometimes simply referred to as "compound (G)") has the following structure. The compound (G) may be used alone or in any combination of two or more kinds in any ratio.

[0314] [ka]

[0315] (In general formula (G), R G1 is a hydrogen atom, a halogen atom, or a monovalent hydrocarbon group which may have a substituent, and R G2 represents a hydrogen atom, an optionally substituted monovalent hydrocarbon group, or an optionally substituted alkoxy group, and X G1 is a divalent hydrocarbon group which may have a substituent, and Gn 1 is an integer between 1 and 3, and Gp 1 is an integer between 0 and 2, and Gq 1 is an integer between 1 and 3, and Gp 1 and Gq 1 The sum of is 2 or 3, and Gp 1 R G1 and Gq 1 X's G1 Two of A may be bonded to each other to form a ring; G1 is a divalent or trivalent atomic group represented by general formula (G1) described later, or a trivalent atomic group represented by general formula (G2) described later.

[0316] (R G1 ) R in general formula (G) in this embodiment G1 represents a hydrogen atom, a halogen atom, or a monovalent hydrocarbon group which may have a substituent. From the viewpoint of ease of industrial handling during the production and storage of compound (G) and during the production of the electrolyte, R G1 is preferably a monovalent hydrocarbon group which may have a substituent, and more preferably a monovalent hydrocarbon group having 1 to 12 carbon atoms which may have a substituent. When the hydrocarbon group has a substituent, the number of carbon atoms contained in the substituent is not included in the number of carbon atoms of the hydrocarbon group.

[0317] In addition, from the viewpoint of suitably forming the insulating film described above, R G1 is also preferably a halogen atom. Specific examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, with a fluorine atom being more preferred.

[0318] R G1 Specific examples of the monovalent hydrocarbon group that can be taken by include an alkyl group, an alkenyl group, an alkynyl group, an aryl group, and an aralkyl group. Among these, from the viewpoint of suppressing side reactions of compound (G) on the electrode, an alkyl group, an alkenyl group, or an alkynyl group is preferred, an alkyl group or an alkenyl group is more preferred, and an alkyl group is particularly preferred.

[0319] R G1 When is an alkyl group, examples thereof include a linear alkyl group, a branched alkyl group, and an alkyl group having a cyclic structure. Of these, a linear alkyl group is preferred from the viewpoint of favorable formation of the insulating coating.

[0320] R G1 When is a linear alkyl group, the number of carbon atoms therein is preferably 1 to 12, more preferably 1 to 6, and even more preferably 1 to 4. Here, the number of carbon atoms is 1 or more, and is preferably 12 or less, more preferably 6 or less, and even more preferably 4 or less.

[0321] Specific examples of the linear alkyl group include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, an n-nonyl group, an n-decyl group, an n-undecyl group, and an n-dodecyl group.

[0322] R G1 When is a branched alkyl group, the number of carbon atoms therein is preferably 2 to 12, more preferably 3 to 6, and even more preferably 3 or 4. Here, the number of carbon atoms is 2 or more, preferably 3 or more, and is preferably 12 or less, more preferably 6 or less, and even more preferably 4 or less.

[0323] Specific examples of the branched alkyl group include branched alkyl groups having 2 to 12 carbon atoms, such as a methylethyl group, a methylpropyl group, a methylbutyl group, a methylpentyl group, a methylhexyl group, a methylheptyl group, a methyloctyl group, a methylnonyl group, a methyldecyl group, a methylundecyl group; a dimethylethyl group (tert-butyl group), a dimethylpropyl group, a dimethylbutyl group, a dimethylpentyl group, a dimethylhexyl group, a dimethylheptyl group, a dimethyloctyl group; a trimethylhexyl group, a trimethylheptyl group; an ethylpentyl group, an ethylhexyl group, an ethylheptyl group, an ethyloctyl group; a propylhexyl group, a propylheptyl group; and a butylhexyl group. Among these, branched alkyl groups having 3 to 6 carbon atoms, such as a methylethyl group, a methylpropyl group, a methylbutyl group, a methylpentyl group, a dimethylethyl group (tert-butyl group), a dimethylpropyl group, or a dimethylbutyl group, are preferred, and branched alkyl groups having 3 to 4 carbon atoms, such as a methylethyl group, a methylpropyl group, or a dimethylethyl group (tert-butyl group), are particularly preferred. In the examples of branched alkyl groups, the position of the branch is optional.

[0324] R G1 When is an alkyl group having a cyclic structure, the number of carbon atoms therein is preferably 3 to 12, more preferably 3 to 8, and even more preferably 6 to 8. Here, the number of carbon atoms is 3 or more, preferably 6 or more, and is preferably 12 or less, and more preferably 8 or less.

[0325] Specific examples of the alkyl group having a cyclic structure include alkyl groups having a cyclic structure having 3 to 12 carbon atoms, such as a cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclononyl group, cyclodecyl group, cyclohexylmethyl group, cyclohexylethyl group, methylcyclohexyl group, dimethylcyclohexyl group, ethylcyclohexyl group, and methylcyclohexylmethyl group. Among these, alkyl groups having a cyclic structure of 3 to 8 carbon atoms, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclohexylmethyl, cyclohexylethyl, methylcyclohexyl, dimethylcyclohexyl, ethylcyclohexyl, and methylcyclohexylmethyl, are preferred, and alkyl groups having a cyclic structure of 6 to 8 carbon atoms, such as cyclohexyl, cyclohexylmethyl, cyclohexylethyl, methylcyclohexyl, dimethylcyclohexyl, ethylcyclohexyl, and methylcyclohexylmethyl, are particularly preferred.

[0326] Among the above, a methyl group, an ethyl group, an n-propyl group, an n-butyl group, a tert-butyl group, an n-pentyl group, or an n-hexyl group is more preferable, a methyl group, an ethyl group, an n-propyl group, an n-butyl group, or a tert-butyl group is even more preferable, and a methyl group or an ethyl group is particularly preferable. The above alkyl groups are preferred because the compound (G) tends to be localized near the surface of the positive electrode active material and / or the negative electrode active material.

[0327] R G1 When is an alkenyl group, the number of carbon atoms therein is preferably 2 to 12, more preferably 2 to 6, and even more preferably 2 to 4. Here, the number of carbon atoms is 2 or more, and is preferably 12 or less, more preferably 6 or less, and even more preferably 4 or less.

[0328] Specific examples of the alkenyl group include alkenyl groups having 2 to 12 carbon atoms, such as vinyl, allyl, isopropenyl, methallyl, 2-butenyl, 3-methyl-2-butenyl, 3-butenyl, and 4-pentenyl. Among these, preferred are alkenyl groups having 2 to 6 carbon atoms, such as vinyl, allyl, methallyl, and 2-butenyl, more preferred are alkenyl groups having 2 to 4 carbon atoms, such as vinyl, allyl, and methallyl, and particularly preferred are vinyl or allyl. The above-mentioned alkenyl groups are preferred because compound (G) can suitably form an insulating coating on the surface of the positive electrode active material and / or negative electrode active material.

[0329] R G1 When is an alkynyl group, the number of carbon atoms is preferably 2 to 12, more preferably 2 to 6, and even more preferably 2 to 4. Here, the number of carbon atoms is 2 or more and preferably 12 or less, more preferably 6 or less, and even more preferably 3 or less.

[0330] Specific examples of the alkynyl group include alkynyl groups having 1 to 12 carbon atoms, such as ethynyl, 2-propynyl, 2-butynyl, 3-butynyl, 4-pentynyl, and 5-hexynyl. Of these, preferred are alkynyl groups having 1 to 6 carbon atoms, such as ethynyl, 2-propynyl, 2-butynyl, and 3-butynyl, more preferred are alkynyl groups having 2 to 4 carbon atoms, such as 2-propynyl and 3-butynyl, and particularly preferred is 2-propynyl. The above-mentioned alkynyl groups are preferred because compound (G) can suitably form an insulating coating on the surface of the positive electrode active material and / or negative electrode active material.

[0331] R G1 When is an aryl group, the number of carbon atoms therein is preferably 6 to 12, more preferably 6 to 7. Here, the number of carbon atoms is preferably 6 or more and 12 or less, more preferably 8 or less.

[0332] Specific examples of the aryl group include aryl groups having 6 to 12 carbon atoms, such as a phenyl group, a tolyl group, or a mesityl group. Of these, from the viewpoint that compound (G) tends to be localized near the surface of the positive electrode active material and / or the negative electrode active material, aryl groups having 6 to 7 carbon atoms, such as a phenyl group or a tolyl group, are preferred, and a phenyl group is particularly preferred.

[0333] R G1 When is an aralkyl group, the number of carbon atoms therein is preferably 7 to 12, and more preferably 7 to 8. Here, the number of carbon atoms is preferably 7 or more and 12 or less, and more preferably 8 or less.

[0334] Specific examples of the aralkyl group include aralkyl groups having 7 to 12 carbon atoms, such as a phenylmethyl group (benzyl group), a phenylethyl group (phenethyl group), a phenylpropyl group, a phenylbutyl group, and a phenylisopropyl group. Of these, from the viewpoint of the tendency of compound (G) to be localized near the surface of the positive electrode active material and / or the negative electrode active material, aralkyl groups having 7 to 8 carbon atoms, such as a benzyl group or a phenethyl group, are preferred, and a benzyl group is particularly preferred.

[0335] R in this embodiment G1 Examples of the substituent that the monovalent hydrocarbon group may have include a cyano group, an isocyanato group, a halogen atom, or a group containing a halogen atom. Of these, an isocyanato group, a halogen atom or a group containing a halogen atom is preferred, and a halogen atom or a group containing a halogen atom is more preferred.

[0336] Specific and preferred examples of halogen atoms are shown in R G1 That is, examples include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, with a fluorine atom being more preferred.

[0337] Specific examples of the group containing a halogen atom include a fluoromethyl group, a chloromethyl group, a bromomethyl group, an iodomethyl group, a trifluoromethyl group, a 2,2,2-trifluoroethyl group, a 2,2,3,3-tetrafluoropropyl group, a 2-fluorophenyl group, etc. Among these, from the viewpoint of suppressing electrochemical side reactions, the fluoromethyl group, the trifluoromethyl group, and the 2,2,2-trifluoroethyl group are preferred, and the 2,2,2-trifluoroethyl group is particularly preferred.

[0338] (R G2 ) R in general formula (G) in this embodiment G2 represents a hydrogen atom, an optionally substituted monovalent hydrocarbon group, or an optionally substituted alkoxy group. Among these, from the viewpoint of minimizing side reactions on the active material of compound (G), a monovalent hydrocarbon group which may have a substituent or an alkoxy group which may have a substituent is preferred, and a monovalent hydrocarbon group which may have a substituent is particularly preferred.

[0339] R G2 When is a monovalent hydrocarbon group, the hydrocarbon group is the same as R G1 The hydrocarbon groups are defined in the same manner as those defined in R , and the preferred hydrocarbon groups are also defined in the same manner. G1 The substituents are defined in the same manner as the substituents that the hydrocarbon group defined in the above may have, and preferred substituents are also the same.

[0340] R G2 When is an alkoxy group, the number of carbon atoms therein is preferably 1 to 12, and more preferably 1 to 6. Here, the number of carbon atoms is 1 or more, and is preferably 12 or less, and more preferably 6 or less.

[0341] Specific examples of the alkoxy group include alkoxy groups having 1 to 12 carbon atoms, such as methoxy, ethoxy, propoxy, butoxy, hexyloxy, octyloxy, decyloxy, and dodecyloxy. Of these, alkoxy groups having 1 to 6 carbon atoms, such as methoxy, ethoxy, propoxy, and butoxy, are preferred, and methoxy and ethoxy groups are particularly preferred from the viewpoint of reducing steric hindrance of compound (G) and allowing it to be suitably concentrated on the surface of the active material.

[0342] The substituents that the alkoxy group may have are R G1 The substituents are defined in the same manner as the substituents that the hydrocarbon group defined in the above may have, and preferred substituents are also the same.

[0343] (X G1 ) In this embodiment, X in general formula (G) G1 represents a divalent hydrocarbon group which may have a substituent. The number of carbon atoms in the divalent hydrocarbon group is preferably 1 to 10, more preferably 1 to 6, and even more preferably 1 to 4. Here, the number of carbon atoms is 1 or more and is preferably 10 or less, more preferably 6 or less, and even more preferably 4 or less. Having the number of carbon atoms in the above range is preferable because compound (G) tends to be localized near the surface of the positive electrode active material and / or negative electrode active material. Note that when the hydrocarbon group has a substituent, the carbon atoms contained in the substituent are not included in this carbon number.

[0344] X G1 Specific examples of the divalent hydrocarbon group that can be taken by include an alkylene group and an alkenylene group, among which an alkylene group is preferred.

[0345] The substituents that the divalent hydrocarbon group may have include R G1 The substituents are defined in the same manner as the substituents that the hydrocarbon group defined in the above may have, and preferred substituents are also the same.

[0346] X G1 When is an alkylene group, specific examples include a linear alkylene group, a branched alkylene group, and an alkylene group having a cyclic structure.

[0347] X G1 When is a linear alkylene group, specific examples include a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, a hexylene group, a heptylene group, an octylene group, a nonylene group, and a decylene group.

[0348] X G1When is a branched alkylene group, specific examples include methylethylene group, methylpropylene group, methylbutylene group, methylpentylene group, methylhexylene group, methylheptylene group, methyloctylene group, methylnonylene group; dimethylethylene group, dimethylpropylene group, dimethylbutylene group, dimethylpentylene group, dimethylhexylene group, dimethylheptylene group, dimethyloctylene group; trimethylhexylene group, trimethylheptylene group; ethylpentylene group, ethylhexylene group, ethylheptylene group, ethyloctylene group; propylhexylene group, propylheptylene group; or butylhexylene group. In the above examples of branched alkyl groups, the position of the branch is optional.

[0349] X G1 When is an alkylene group having a cyclic structure, specific examples include a cyclohexylene group.

[0350] Among the above, methylene group, ethylene group, propylene group, butylene group, pentylene group, hexylene group, methylethylene group, methylpropylene group, methylbutylene group, methylpentylene group, and cyclohexylene group are preferred, and methylene group, ethylene group, propylene group, butylene group, methylethylene group, and methylpropylene group are more preferred. The above alkylene groups are preferred because compound (G) tends to be localized near the surface of the positive electrode active material and / or negative electrode active material.

[0351] (Gn 1 ) In this embodiment, Gn in general formula (G) 1 represents an integer of 1 to 3. From the viewpoint of suppressing battery swelling, Gn 1 is preferably 2 or 3. 1 If is 1 or 2, there are multiple R G2 may be the same or different, and from the viewpoint of ease of synthesis, it is preferable that they are the same.

[0352] Gn 1 If is 1, then R G1 is an alkyl group, RG2 is an alkyl group, and X G1 is an alkylene group and A G1 is a combination of divalent atomic groups having a carbonate structure; R G1 is an alkyl or alkenyl group, R G2 is an alkyl group, and X G1 is an alkylene group and A G1 A combination of divalent atomic groups having an ester structure; R G1 is an alkyl group, R G2 is an alkyl group, and X G1 is an alkylene group and A G1 is preferably a combination of divalent atomic groups having a sulfone structure.

[0353] Gn 1 If is 2, R G1 is an alkyl group, R G2 is an alkyl group, and X G1 is an alkylene group and A G1 is a combination of divalent atomic groups having a carbonate structure; R G1 is an alkyl group, R G2 is an alkyl group, and X G1 is an alkylene group and A G1 A combination of divalent atomic groups having an ester structure; R G1 is an alkyl group, R G2 is an alkyl group, and X G1 is an alkylene group and A G1 a combination of divalent atomic groups having a sulfone structure; or R G1 is an alkyl group, R G2 is an alkyl group, and X G1 is an alkylene group and A G1 is preferably a combination of trivalent atomic groups having an isocyanurate structure.

[0354] n G1 If is 3, R G1 is an alkyl group, and X G1 is an alkylene group and A G1 is a combination of divalent atomic groups having a carbonate structure; R G1 is an alkyl group, and X G1 is an alkylene group and A G1A combination of divalent atomic groups having an ester structure; R G1 is an alkyl group, and X G1 is an alkylene group and A G1 a combination of divalent atomic groups having a sulfone structure; or R G1 is an alkyl group, and X G1 is an alkylene group and A G1 is preferably a combination of trivalent atomic groups having an isocyanurate structure.

[0355] (Gp 1 , Gq 1 ) In this embodiment, Gp in general formula (G) 1 represents an integer between 0 and 2. Gp 1 If is 2, there are two R G1 may be the same or different, but from the viewpoint of ease of synthesis, it is preferred that they are the same.

[0356] In this embodiment, Gq in general formula (G) 1 represents an integer from 1 to 3. Gq 1 is 2 or 3, there are 2 or 3 -X G1 Si(F) Gn1 (R G2 ) 3-Gn1 may be the same or different, but from the viewpoint of ease of synthesis, it is preferable that they are the same. In this embodiment, Gp 1 and Gq 1 The sum is 2 or 3.

[0357] From the viewpoint of reducing electrochemical side reactions and favorably forming a film on the surface of the active material, A in general formula (G) G1 is a divalent or trivalent atomic group represented by general formula (G1), Gp 1 is 1 and Gq 1 is preferably 1 or 2, and Gp 1 is 1 and Gq 1 is more preferably 1.

[0358] From the viewpoint of reducing electrochemical side reactions and favorably forming a film on the surface of the active material, A in general formula (G) G1 is a trivalent atomic group represented by general formula (G2), Gp 1 is 0 and Gq 2 is preferably 3.

[0359] Gp 1 R G1 and Gq 1 X's G1 Two of these may be bonded to each other to form a ring. That is, in the embodiment of forming a ring, R G1 Comrade, X G1 R G1 and X G1 In terms of ease of synthesis, R G1 and X G1 are bonded to form a ring. More preferred embodiments include the following structures:

[0360] [ka]

[0361] (A G1 ) In this embodiment, A in general formula (G) G1 represents a divalent or trivalent atomic group represented by the following general formula (G1), or a trivalent atomic group represented by the later-described general formula (G2). The divalent or trivalent atomic group represented by general formula (G1) will be explained.

[0362] [ka]

[0363] In this embodiment, Z in general formula (G1) G1 is a carbon atom, a sulfur atom, a phosphorus atom, or a boron atom; Y G101 is an oxygen atom or a sulfur atom; Y G1 ~Y G3are each independently a single bond, an oxygen atom, a sulfur atom, or NR G101 Group(-NR G101 -group); R G101 is a hydrogen atom or a monovalent hydrocarbon group; R G101 When R is a monovalent hydrocarbon group, G101 represents adjacent R G1 or X G1 may be bonded to form a ring. Gr 1 is Z G1 is a carbon atom, it is 1, and Z G1 is 0, 1, or 2 when is a sulfur atom, and Z G1 is 0 or 1 when is a phosphorus atom, and Z G1 is 0 when it is a boron atom. Gr 2 is Z G1 is 0 when is a carbon atom or a sulfur atom, and Z G1 is a phosphorus atom or a boron atom, the value is 1. * indicates R in the above general formula (G). G1 or X G1 represents the binding site with However, Z G1 is a sulfur atom and Gr 1 is 2, and Y G1 and Y G2 and (iii) are both single bonds.

[0364] (R G101 ) In this embodiment, Y in general formula (G1) G1 ~Y G3 NR G101 When R is a group, G101 The monovalent hydrocarbon group that can be taken by R in general formula (G) G1 is synonymous with the monovalent hydrocarbon group defined by

[0365] When general formula (G1) is a divalent atomic group (hereinafter, may be referred to as a "divalent group"), examples of the combination of atoms constituting the divalent atomic group include a divalent atomic group consisting of an oxygen atom, a sulfur atom, and an oxygen atom, a divalent atomic group consisting of a carbon atom and an oxygen atom, a divalent atomic group consisting of a hydrogen atom, a carbon atom, and an oxygen atom, a divalent atomic group consisting of a sulfur atom, an oxygen atom, and a sulfur atom, a divalent atomic group consisting of a carbon atom, an oxygen atom, and a sulfur atom, or a divalent atomic group consisting of a hydrogen atom, a carbon atom, an oxygen atom, and a sulfur atom.

[0366] Specific examples of the divalent atomic group consisting of an oxygen atom, a carbon atom and an oxygen atom, or a divalent atomic group consisting of a hydrogen atom, a carbon atom and an oxygen atom include divalent atomic groups having a ketone structure, a carboxylic acid ester structure, or a carbonate structure. Specifically, for example, Z G1 is a carbon atom; Y G101 is an oxygen atom; Y G1 ~Y G3 are each independently a single bond or an atomic group which is an oxygen atom.

[0367] Specific examples of the divalent group having a ketone structure include a -CO- group. G1 is a carbon atom, and Y G101 is an oxygen atom, and Y G1 and Y G2 are single bonds, and Gr 1 is 1, and Gr 2 is 0. Specific examples of the divalent group having a carboxylic acid ester structure include a -COO- group. G1 is a carbon atom, and Y G101 is an oxygen atom, and Y G1 and Y G2 One of the atoms is an oxygen atom and the other is a single bond, and Gr 1 is 1, and Gr 2 is 0. Specific examples of the divalent group having a carbonate structure include an -OCOO- group. G1is a carbon atom, and Y G101 is an oxygen atom, and Y G1 and Y G2 are both oxygen atoms, and Gr 1 is 1, and Gr 2 is 0. Among these, from the viewpoint of reducing electrochemical side reactions and suitably forming a coating on the surface of the active material, divalent groups having a carboxylic acid ester structure and divalent groups having a carbonate structure are more preferred, and -COO- group and -OCOO- group are particularly preferred.

[0368] Specific examples of the divalent atomic group consisting of a sulfur atom, an oxygen atom, and a sulfur atom, the divalent atomic group consisting of a carbon atom, an oxygen atom, and a sulfur atom, or the divalent atomic group consisting of a hydrogen atom, a carbon atom, an oxygen atom, and a sulfur atom include divalent groups having a sulfide structure, a sulfone structure, a sulfonate ester structure, a sulfate ester structure, a sulfoxide structure, a sulfite ester structure, a sulfinate ester structure, a thiocarbonyl structure, and a thioester structure.

[0369] More specifically, for example, Z G1 is a carbon atom, and Y G101 is an oxygen atom, and Y G1 ~Y G3 Atomic group in which all atoms are sulfur atoms; Z G1 is a carbon atom, and Y G101 is a sulfur atom, and Y G1 ~Y G3 are each independently a single bond, an oxygen atom, or a sulfur atom; or Z G1 is a sulfur atom, and Y G101 is an oxygen atom or a sulfur atom, and Y G1 ~Y G3 are each independently a single bond, an oxygen atom, or an atomic group which is an oxygen atom.

[0370] Specific examples of the divalent group having a sulfide structure include an -S- group. Specific examples of divalent groups having a sulfonate structure include -SO3- groups. Specific examples of divalent groups having a sulfate ester structure include -OSO3- groups. Specific examples of divalent groups having a sulfoxide structure include -SO- groups. Specific examples of divalent groups having a sulfite ester structure include an -OSO- group. Specific examples of the divalent group having a sulfinate structure include an -SOO- group. Examples of the divalent group having a thiocarbonyl structure include an -OCSO- group and an -CSO- group. Specific examples of the divalent group having a thioester structure include a -COS- group, a -OCOS- group, a -SCOS- group, etc. In addition, it may also be a divalent group having a dithiocarboxylic acid ester structure such as a -CSS- group, a -OCSS- group, or a -SCSS- group.

[0371] Among these, from the viewpoint of minimizing electrochemical side reactions and suitably forming a coating on the surface of the active material, the divalent group represented by the above general formula (G1) is preferably a -SO3- group, a -OSO3- group, a -OSOO- group, or a -SOO- group, more preferably a -SO3- group or a -OSO3- group, and particularly preferably a -SO3- group.

[0372] When general formula (G1) is a trivalent atomic group (hereinafter, sometimes referred to as a "trivalent group"), examples of the combination of atoms constituting the trivalent atomic group include a trivalent atomic group having at least one atom selected from an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorus atom, and a boron atom.

[0373] Specific examples include a trivalent atomic group consisting of a nitrogen atom, a phosphorus atom, a boron atom, and a carbon atom, a trivalent atomic group consisting of a nitrogen atom and an oxygen atom, a trivalent atomic group consisting of a hydrogen atom, a carbon atom, a nitrogen atom, and an oxygen atom, a trivalent atomic group consisting of a carbon atom, a nitrogen atom, and a sulfur atom, a trivalent atomic group consisting of a nitrogen atom, an oxygen atom, and a sulfur atom, a trivalent atomic group consisting of a hydrogen atom, a carbon atom, a nitrogen atom, and a sulfur atom, a trivalent atomic group consisting of a carbon atom, a nitrogen atom, an oxygen atom, and a sulfur atom, a trivalent atomic group consisting of a phosphorus atom, an oxygen atom, and a phosphorus atom, a trivalent atomic group consisting of a hydrogen atom, a nitrogen atom, an oxygen atom, and a phosphorus atom, a boron atom, or a trivalent atomic group consisting of a boron atom and an oxygen atom.

[0374] Specifically, for example, Z G1 is a carbon atom, and Y G101 is an oxygen atom, and Y G1 ~Y G3 are each independently, NR G101 Examples of such groups include atomic groups in which

[0375] Examples of the trivalent atomic group consisting of a carbon atom, a nitrogen atom, and an oxygen atom, or the trivalent atomic group consisting of a hydrogen atom, a carbon atom, a nitrogen atom, and an oxygen atom include trivalent groups having an amide structure, a urethane structure, or a urea structure. Specific examples of these include the atomic groups shown below. Here, * represents R in the above general formula (G). G1 or X G1 This is the binding site for

[0376] [ka]

[0377] Examples of the trivalent atomic group consisting of carbon, nitrogen, and sulfur atoms, the trivalent atomic group consisting of nitrogen, oxygen, and sulfur atoms, the trivalent atomic group consisting of hydrogen, carbon, nitrogen, and sulfur atoms, or the trivalent atomic group consisting of carbon, nitrogen, oxygen, and sulfur atoms include trivalent groups having a thiocarbonyl structure, a thioester structure, or a sulfonamide structure. In addition, it may also be a trivalent group having a dithiocarboxylic acid ester structure.

[0378] Specifically, for example, Z G1 is a carbon atom, and Y G101 is a sulfur atom, and Y G1 ~Y G3 However, each independently, NR G101 or Z G1 is a carbon atom, and Y G101 is an oxygen atom, and Y G1 ~Y G3 However, each independently, NR G101 Examples of such groups include atomic groups in which Specific examples of these include the atomic groups shown below. Here, * represents R in the above general formula (G). G1 or X G1 This is the binding site for

[0379] [ka]

[0380] Examples include a phosphorus atom, a trivalent atomic group consisting of an oxygen atom and a phosphorus atom, and a trivalent atomic group consisting of a hydrogen atom, a nitrogen atom, and an oxygen atom or a phosphorus atom. Specifically, for example, Z G1 is a phosphorus atom, and more specific examples thereof include trivalent groups having a phosphine oxide structure, a phosphinate ester structure, a phosphonate ester structure, a phosphate ester structure, a phosphoric acid amide structure, a phosphine structure, a phosphinite ester structure, a phosphonate ester structure, or a phosphite ester structure. Specific examples of these include the atomic groups shown below. Here, * represents R in the above general formula (G). G1 or X G1 This is the binding site for

[0381] [ka]

[0382] Among these, the following atomic groups are preferred from the viewpoint of causing fewer electrochemical side reactions and favorably forming a film on the surface of the active material.

[0383] [ka]

[0384] Among these, the following atomic groups are particularly preferred:

[0385] [ka]

[0386] Examples of the trivalent atomic group consisting of a boron atom or a boron atom and an oxygen atom include a trivalent group having a trialkylborane structure, a borinic acid ester structure, a boronate ester structure, and a borate ester structure. Specific examples of these include the following atomic groups: where * represents R in the above general formula (G). G1 or X G1 This is the binding site for

[0387] [ka]

[0388] Among these, the divalent or trivalent atomic group represented by formula (G1) is preferably a divalent or trivalent atomic group represented by the following general formula (G1-1), in terms of reducing electrochemical side reactions and favorably forming a coating on the surface of the active material.

[0389] [ka]

[0390] Z G11 is a carbon atom, a sulfur atom, or a phosphorus atom, and Y G11 ~Y G13 are each independently a single bond or an oxygen atom. Gr 11 is Z G11 is a carbon atom, it is 1, and Z G11 is 0, 1, or 2 when is a sulfur atom, and Z G11 is 0 or 1 when it is a phosphorus atom. Gr 12 is Z G11 is 0 when is a carbon atom or a sulfur atom, and Z G11 is a phosphorus atom, it is 1. * indicates R in the above general formula (G). G1 or X G1 represents the binding site with However, Z G11 is a sulfur atom and Gr 11 When is 2, Y G11 and Y G12 cannot both be single bonds.

[0391] Z in general formula (G1-1) G11 , Y G11 ~Y G13 , Gr 11 , and Gr 12 represents, to the extent applicable, Z in the above general formula (G1). G1 , Y G1 ~Y G3 , Gr 1 , and Gr 2 The above conditions can be applied respectively.

[0392] Next, A in general formula (G) in this embodiment G1 is a trivalent atomic group represented by the following general formula (G2).

[0393] [ka]

[0394] In this embodiment, Y in general formula (G2) G4 ~Y G6 are each independently an oxygen atom, a sulfur atom, or NR G201 Group (=NR G201 R G201 is a hydrogen atom or a monovalent hydrocarbon group. * indicates R in the above general formula (G). G1 or X G1 represents the binding site with

[0395] (R G201 ) The above R G201 The monovalent hydrocarbon group in the general formula (G) is G1 is synonymous with the monovalent hydrocarbon group defined by

[0396] Among these, the trivalent atomic group represented by general formula (G2) is preferably an atomic group represented by the following formula (G2)', from the viewpoint of reducing electrochemical side reactions and favorably forming a film on the surface of the active material. Here, * represents R in the above general formula (G). G1 or X G1 The binding site is shown.

[0397] [ka]

[0398] Among the atomic groups represented by the above general formula (G1) or (G2), the following divalent or trivalent groups are preferred. Preferably, the alkyl group is a divalent group having a ketone structure, a divalent group having a carbonate structure, a divalent group having a carboxylic acid ester structure, a divalent group having a sulfonic acid ester structure, a divalent group having a sulfate ester structure, a divalent group having a sulfite ester structure, a divalent group having a sulfinic acid structure, a trivalent group having a phosphonic acid ester structure, a trivalent group having a phosphate ester structure, or a trivalent group having an isocyanurate structure. More preferred is a divalent group having a carbonate structure, a divalent group having a carboxylic acid ester structure, a divalent group having a sulfonic acid ester structure, a divalent group having a sulfate ester structure, a trivalent group having a phosphonic acid ester structure, a trivalent group having a phosphate ester structure, or a trivalent group having an isocyanurate structure. More preferred is a divalent group having a carbonate structure, a divalent group having a carboxylic acid ester structure, a divalent group having a sulfonic acid ester structure, a trivalent group having a phosphonic acid ester structure, a trivalent group having a phosphate ester structure, or a trivalent group having an isocyanurate structure. A divalent group having a carbonate structure or a divalent group having a carboxylic acid ester structure is particularly preferred.

[0399] Specific examples of compounds represented by the above general formula (G) are given below. The compound represented by general formula (G) according to this embodiment is not limited to the compounds represented by formulae (G3-1) to (G3-106), (G2-1) to (G2-148), and (G1-1) to (G1-148) shown below.

[0400] [ka]

[0401] [ka]

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[0404]

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[0405]

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[0414]

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[0416]

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[0417]

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[0418]

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[0423]

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[0437] [ka]

[0438] Among these, A is the most suitable from the viewpoint of ease of obtaining raw materials and ease of synthesis. G1 is a divalent atomic group having a carbonate structure, a divalent atomic group having a carboxylic acid ester structure, a trivalent atomic group having a phosphate ester structure, or a trivalent atomic group having an isocyanurate structure, and R G1 is a methyl group, an ethyl group, or a trifluoroethyl group, and R G2 is a methyl group or an ethyl group, and X G1 is an alkylene group having 1 to 4 carbon atoms, and Gn 1 is preferably 1 or 2. Among them, A G1 is more preferably a divalent atomic group having a carbonate structure or a divalent atomic group having a carboxylic acid ester structure.

[0439] The compound represented by general formula (G) may be produced by any known method without any particular limitation.

[0440] In this embodiment, the blending ratio of compound (G) to the total amount of the electrolyte solution is not limited and may be any as long as it does not significantly impair the effects of the present invention, but it is preferably, for example, 0.001 to 10 mass% and used as an additive. Here, the blending ratio is, for example, 0.001 mass% or more, preferably 0.01 mass% or more, more preferably 0.1 mass% or more, and for example, 10 mass% or less, preferably 5 mass% or less, more preferably 3 mass% or less, and even more preferably 2 mass% or less.

[0441] In addition, the content ratio of the compound (G) relative to the total amount of the electrolyte solution in this embodiment is not limited, and is any as long as it does not significantly impair the effects of the present invention, but for example, more than 0 mass% and 10 mass% or less is preferable. Here, the content ratio may be more than 0 mass%, for example, 0.001 mass% or more, preferably 0.01 mass% or more, more preferably 0.1 mass% or more, and for example, 10 mass% or less, preferably 5 mass% or less, more preferably 3 mass% or less, and even more preferably 2 mass% or less. When the content of compound (G) is within the above range, it is possible to suitably prevent inhibitions such as an increase in resistance caused by excessively covering the negative electrode surface with a film containing compound (G), and the action at the electrode interface proceeds more suitably, making it possible to optimize the battery characteristics.

[0442] In this embodiment, the compound (G) content in the electrolyte solution is often different from the content of the compound (G) measured when the resulting battery is disassembled. Specifically, the content of the compound (G) measured when the battery is disassembled after charging and discharging and the electrolyte is removed again is often significantly lower than the content when the compound (G) is contained in the electrolyte solution and actually used to fabricate the battery. Therefore, when the battery is disassembled and the electrolyte solution extracted contains even a very small amount of compound (G), the electrolyte solution is considered to fall within the scope of the present embodiment.

[0443] Furthermore, when a battery is actually fabricated using an electrolyte solution containing compound (G) according to this embodiment, even if the electrolyte solution extracted after disassembling the battery contains only a small amount of compound (G), compound (G) may be present in other components of the battery. Specifically, compound (G) is often detected on the positive electrode, negative electrode, or separator. Therefore, when compound (G) is detected in one or more of the positive electrode, negative electrode, and separator, it can be assumed that the total amount of compound (G) contained in the electrolyte solution and other components was contained in the electrolyte solution. Under this assumption, the content of compound (G) is preferably within the above range.

[0444] [1-1H. Compound (H) containing an anion represented by general formula (H)] The compound containing an anion represented by general formula (H) in this embodiment (hereinafter, sometimes simply referred to as "compound (H)") has an anion having the following structure: In this embodiment, one type of compound (H) may be used alone, or two or more types may be used in any ratio and combination.

[0445] [ka]

[0446] (In general formula (H), X H is a sulfur atom or a phosphorus atom, Hm is 1 or 2, and R H1 ~R H4 are each independently a fluorine atom, an alkyl group having 1 to 4 carbon atoms, a halogenated alkyl group having 1 to 4 carbon atoms, or a hydroxy group, provided that X H If is a sulfur atom, Hm is 2, and R H4 does not exist, and X H If is a phosphorus atom, Hm is 1.)

[0447] X H is a sulfur atom or a phosphorus atom, while X H If is a sulfur atom, Hm is 2, and R H4 does not exist, and X HIf is a phosphorus atom, Hm is 1. X H From the viewpoint of suppressing battery swelling, sulfur atoms are preferred.

[0448] R H1 ~R H4 With regard to the above, the number of carbon atoms in the alkyl group having 1 to 4 carbon atoms is preferably 1 to 3, and particularly preferably 1 to 2. Here, the number of carbon atoms is 1 or more and 4 or less, preferably 3 or less, and more preferably 2 or less. Specific examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, and a tert-butyl group. Among these, a methyl group and an ethyl group are preferred. The above-mentioned alkyl groups are preferred because the compound represented by general formula (H) tends to be localized near the surface of the positive electrode active material and / or the negative electrode active material.

[0449] R H1 ~R H4 With regard to the above, examples of the alkyl group in the halogenated alkyl group having 1 to 4 carbon atoms include the same as the alkyl group having 1 to 4 carbon atoms described above. Examples of halogen atoms include fluorine atoms, chlorine atoms, and bromine atoms, among which fluorine atoms are preferred in terms of reactivity with the active material.

[0450] The halogenated alkyl group may be an alkyl group in which one or more hydrogen atoms have been substituted with halogen atoms, and may be a perhalogenated alkyl group in which all hydrogen atoms have been substituted with halogen atoms. As the halogenated alkyl group having 1 to 4 carbon atoms, for example, a fluoromethyl group, a trifluoromethyl group, a 2-fluoroethyl group, a 2,2-difluoroethyl group, and a pentafluoroethyl group are preferred in terms of reactivity with the active material.

[0451] The compound (H) containing the anion represented by the general formula (H) is X H is a sulfur atom, Hm is 2, and R H1 ~R H3 is a combination of all halogen atoms, XH is a phosphorus atom, Hm is 1, and R H1 ~R H4 is preferably a combination in which all of X are halogen atoms, H is a sulfur atom, Hm is 2, and R H1 ~R H3 and are all halogen atoms.

[0452] In the present embodiment, suitable counter cations of the anion represented by general formula (H) include alkali metal cations, alkaline earth metal cations, ammonium cations, and phosphonium cations. Among these, alkali metal cations and alkaline earth metal cations are more preferred, and alkali metal cations are even more preferred.

[0453] Specific examples of alkali metal cations include lithium cations (Li + ), sodium cation (Na + ), potassium cation (K + ), cesium cation (Cs + ) are preferred examples. A specific example of an alkaline earth metal cation is the magnesium cation (Mg 2+ ), calcium cation (Ca 2+ ) are preferred examples.

[0454] Among these, lithium cation, sodium cation, cesium cation, and magnesium cation are more preferable, and the more preferable counter cation varies depending on the battery in which the electrolyte solution according to this embodiment is used. For example, when the electrolyte solution according to this embodiment is used in a lithium ion battery, the counter cation is more preferably a lithium cation, and when it is used in a sodium ion battery, the counter cation is more preferably a sodium cation.

[0455] More specific examples of the anion represented by general formula (H) include anions having the following structures:

[0456] [ka]

[0457] The method for producing the compound containing the anion represented by general formula (H) is not particularly limited, and it can be produced by any known method.

[0458] In this embodiment, the amount of compound (H) relative to the total amount of the electrolyte solution is not limited and may be any amount as long as it does not significantly impair the effects of the present invention. For example, it is preferable to use it as an additive in an amount of 0.001 to 10% by mass. Here, the amount is, for example, 0.001% by mass or more, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, even more preferably 0.2% by mass or more, and, for example, 10% by mass or less, preferably 5% by mass or less, more preferably 3% by mass or less, even more preferably 2% by mass or less, particularly preferably 1.5% by mass or less, and most preferably 1% by mass or less. When the amount of compound (H) is within the above range, inhibition of charge / discharge reactions due to excessive electrode surface coverage by side reaction products on the electrode can be prevented. Furthermore, the interaction at the electrode interface proceeds more efficiently, optimizing battery characteristics.

[0459] In addition, in this embodiment, there is no limitation on the content ratio of compound (H) relative to the total amount of the electrolyte solution, and it can be any content as long as it does not significantly impair the effects of the present invention. For example, it is preferable that the content ratio is greater than 0% by mass and less than or equal to 10% by mass. Here, the content ratio may be greater than 0% by mass, for example, 0.001% by mass or more, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and for example, 10% by mass or less, preferably 5% by mass or less, more preferably 3% by mass or less, even more preferably 2% by mass or less, particularly preferably 1.5% by mass or less, and most preferably 1% by mass or less. When the amount of compound (H) is within the above range, inhibition of charge / discharge reactions due to excessive coverage of the electrode surface by side reaction products on the electrode can be suitably prevented. Furthermore, the action at the electrode interface proceeds more suitably, making it possible to optimize battery characteristics.

[0460] In this embodiment, the compound (H) content in the electrolyte solution is often different from the content of the compound (H) measured when the resulting battery is disassembled. Specifically, the content measured when the battery is disassembled after charging and discharging and the electrolyte is extracted again is often significantly lower than the compound amount when the compound (H) is contained in the electrolyte solution and actually used to fabricate the battery. Therefore, when a compound (H) containing an anion represented by general formula (H) can be detected even in a very small amount from the electrolyte solution extracted by disassembling the battery, the electrolyte solution is considered to fall under the category of the electrolyte solution of this embodiment.

[0461] Furthermore, when a battery is fabricated using an electrolyte solution containing compound (H) according to this embodiment, even if the electrolyte solution extracted after disassembling the battery contains only a small amount of compound (H), compound (H) may be present in other components of the battery. Specifically, compound (H) is often detected on the positive electrode, negative electrode, or separator. Therefore, when compound (H) is detected in one or more of the positive electrode, negative electrode, and separator, it can be assumed that the total amount of compound (H) contained in the electrolyte solution and other components was contained in the electrolyte. Under this assumption, the content of compound (H) containing an anion represented by general formula (H) is preferably within the above range.

[0462] [1-1I. Compound (I) represented by general formula (I)] The compound represented by general formula (I) in this embodiment (hereinafter sometimes simply referred to as "compound (I)") has the following structure: In this embodiment, one type of compound (I) may be used alone, or two or more types may be used in any ratio and combination.

[0463] [ka]

[0464] In the above general formula (I), R I1 and R I2each independently represents a hydrocarbon group having 1 to 10 carbon atoms which may have a substituent, and R I1 and R I2 At least one of the groups is a fluorinated alkyl group.

[0465] The number of carbon atoms in the hydrocarbon group having 1 to 10 carbon atoms is preferably 1 to 5, more preferably 1 to 4, even more preferably 1 to 2 or 2 to 3, and particularly preferably 1 or 2. Here, the number of carbon atoms is 1 or more, or may be 2 or more, and is 10 or less, preferably 5 or less, more preferably 4 or less, even more preferably 3 or less, and even more preferably 2 or less.

[0466] Also, R I1 and R I2 At least one of the groups is a fluorinated alkyl group, the number of carbon atoms of which is 1 to 10, preferably 1 to 5, more preferably 1 to 4, and particularly preferably 2 to 3. Here, the number of carbon atoms is 1 or more, preferably 2 or more, and is 10 or less, preferably 5 or less, more preferably 4 or less, and even more preferably 3 or less.

[0467] The hydrocarbon group having 1 to 10 carbon atoms may be a saturated hydrocarbon group or an unsaturated hydrocarbon group, but from the viewpoint of compound stability, a saturated hydrocarbon group is preferred. When the hydrocarbon group having 1 to 10 carbon atoms is a saturated hydrocarbon group, i.e., an alkyl group, it may be linear, branched, or cyclic. From the viewpoint of compound stability, however, a linear alkyl group or a branched alkyl group is more preferred, and a linear alkyl group is even more preferred.

[0468] Specific examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a tert-butyl group, an n-pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, and a decyl group. Among these, a methyl group, an ethyl group, an isopropyl group, an n-propyl group, an n-butyl group, a tert-butyl group, an n-pentyl group, and a hexyl group are preferred, a methyl group, an ethyl group, an isopropyl group, an n-propyl group, an n-butyl group, and a tert-butyl group are more preferred, and a methyl group and an ethyl group are particularly preferred. The above-mentioned alkyl groups are preferred in terms of melting point and viscosity.

[0469] The hydrocarbon group having 1 to 10 carbon atoms may have a substituent, that is, some or all of the hydrogen atoms may be substituted with other functional groups or other atoms, as long as the effects of the present invention are not impaired. Examples of other atoms include halogen atoms, more specifically fluorine atoms, chlorine atoms, bromine atoms, etc., with a fluorine atom being preferred. Other functional groups include a cyano group, an isocyanato group, an acyl group (-(C=O)-Rir), an acyloxy group (-O(C=O)-Rir), an alkoxycarbonyl group (-(C=O)O-Rir), a sulfonyl group (-SO2-Rir), a sulfonyloxy group (-O(SO2)-Rir), an alkoxysulfonyl group (-(SO2)-O-Rir), an alkoxysulfonyloxy group (-O-(SO2)-O-Rir), an alkoxycarbonyloxy group (-O-(C=O)-O-Rir), an ether group (-O-Rir), and a trifluoromethyl group. Rir represents an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, or an alkynyl group having 2 to 10 carbon atoms.

[0470] Specific examples of fluorinated alkyl groups include a fluoromethyl group, a difluoromethyl group, a trifluoromethyl group, a 2-fluoroethyl group, a 2,2-difluoroethyl group, a 2,2,2-trifluoroethyl group, a 1,1,2,2,2-pentafluoroethyl group, a 2,2,3,3-tetrafluoropropyl group, a 2,2,3,3,3-pentafluoropropyl group, a 1,1,1,3,3,3-hexafluoropropyl group, and a 2,2,3,3,4,4,4-heptafluorobutyl group. Among these, preferred are a fluoromethyl group, a difluoromethyl group, a trifluoromethyl group, a 2-fluoroethyl group, a 2,2-difluoroethyl group, a 2,2,2-trifluoroethyl group, a 2,2,3,3-tetrafluoropropyl group, and a 2,2,3,3,3-pentafluoropropyl group, more preferred are a fluoromethyl group, a difluoromethyl group, a trifluoromethyl group, and a 2,2,2-trifluoroethyl group, and particularly preferred is a 2,2,2-trifluoroethyl group.

[0471] R I1 and R I2 are each independently a hydrocarbon group having 1 to 2 carbon atoms which may have a substituent, from the viewpoint of viscosity of the compound, and R I1 and R I2 At least one of them is preferably a fluorinated alkyl group.

[0472] R I1 and R I2 However, from the viewpoint of viscosity of the compound, it is preferable that only one of the groups is a fluorinated alkyl group. Furthermore, from the viewpoint of enhancing reactivity in a battery, it is preferable that both groups are fluorinated alkyl groups. Also, R I1 and R I2 The carbon numbers of the alkyl groups in may be the same or different, but the difference therebetween is preferably 2 or less, more preferably 1 or less.

[0473] More specific examples of the compound represented by general formula (I) include the following compounds. dimethyl carbonate derivatives such as fluoromethyl methyl carbonate, difluoromethyl methyl carbonate, trifluoromethyl methyl carbonate, bis(fluoromethyl)carbonate, bis(difluoromethyl)carbonate, and bis(trifluoromethyl)carbonate; ethyl methyl carbonate derivatives such as 2-fluoroethyl methyl carbonate, ethyl fluoromethyl carbonate, 2,2-difluoroethyl methyl carbonate, 2-fluoroethyl fluoromethyl carbonate, ethyl difluoromethyl carbonate, 2,2,2-trifluoroethyl methyl carbonate, 2,2-difluoroethyl fluoromethyl carbonate, 2-fluoroethyl difluoromethyl carbonate, and ethyl trifluoromethyl carbonate; diethyl carbonate derivatives such as ethyl (2-fluoroethyl) carbonate, ethyl (2,2-difluoroethyl) carbonate, bis(2-fluoroethyl) carbonate, ethyl (2,2,2-trifluoroethyl) carbonate, 2,2-difluoroethyl-2'-fluoroethyl carbonate, bis(2,2-difluoroethyl) carbonate, 2,2,2-trifluoroethyl-2'-fluoroethyl carbonate, 2,2,2-trifluoroethyl-2',2'-difluoroethyl carbonate, and bis(2,2,2-trifluoroethyl) carbonate; Examples thereof include methyl-2,2,3,3-tetrafluoropropyl carbonate, methyl-2,2,3,3,3-pentafluoropropyl carbonate, 1,1,2,3,3,3-hexafluoropropyl methyl carbonate, 2,2,3,3,4,4,4-heptafluorobutyl methyl carbonate, ethyl-2,2,3,3-tetrafluoropropyl carbonate, ethyl-2,2,3,3,3-pentafluoropropyl carbonate, ethyl-1,1,2,3,3,3-hexafluoropropyl carbonate, and ethyl-2,2,3,3,4,4,4-heptafluorobutyl carbonate.

[0474] Among these, fluoromethyl methyl carbonate, difluoromethyl methyl carbonate, trifluoromethyl methyl carbonate, bis(fluoromethyl)carbonate, bis(difluoromethyl)carbonate, bis(trifluoromethyl)carbonate, 2-fluoroethyl methyl carbonate, 2,2-difluoroethyl methyl carbonate, 2,2,2-trifluoroethyl methyl carbonate, and bis(2,2,2-trifluoroethyl)carbonate are preferred, and 2,2,2-trifluoroethyl methyl carbonate and bis(2,2,2-trifluoroethyl)carbonate are more preferred.

[0475] In this embodiment, the content ratio of compound (I) relative to the total amount of the electrolyte solution is not particularly limited and may be any as long as it does not significantly impair the effects of the present invention. For example, the content is preferably 0.01 to 60 mass%, more preferably 40 mass% or less, 0.01 to 10 mass%, or more than 10 mass% but 60 mass% or less. Here, from the viewpoint of more easily exhibiting the effect of suppressing electrode swelling during repeated charge and discharge, the content is, for example, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and even more preferably 0.3% by mass or more, and is, for example, preferably 10% by mass or less, more preferably 8% by mass or less, and even more preferably 5% by mass or less. The content of Compound (I) is preferably, for example, more than 10% by mass and not more than 60% by mass, more preferably more than 10% by mass and not more than 40% by mass, even more preferably more than 10% by mass and not more than 30% by mass, even more preferably more than 10% by mass and not more than 25% by mass, and particularly preferably more than 10% by mass and not more than 20% by mass. Here, the content is preferably, for example, more than 10% by mass, more preferably 15% by mass or more, and also, for example, preferably not more than 60% by mass, more preferably not more than 50% by mass, even more preferably not more than 40% by mass, even more preferably not more than 35% by mass, particularly preferably not more than 30% by mass, particularly preferably not more than 25% by mass, and most preferably not more than 20% by mass. By keeping the content within the above range, the viscosity of the electrolyte can be kept within an appropriate range, the decrease in ionic conductivity can be reduced, and the electrode swelling suppression effect is more easily exhibited even when repeatedly charged and discharged in a high-temperature environment.

[0476] [1-2. Electrolytes] The electrolyte contained in the electrolytic solution in this embodiment varies depending on the type of secondary battery to which the electrolytic solution is applied, but for example, lithium salts are preferred, and sodium salts and potassium salts are also preferred. Note that when the specific compounds in this embodiment are Compounds (A) to (D) and Compound (H), and these compounds contain lithium as a (counter) cation, Compounds (A) to (D) and Compound (H) can also function as lithium salts in the electrolyte. However, in this embodiment, Compounds (A) to (D) and Compound (H) are nominally additives, and therefore Compounds (A) to (D) and Compound (H) are not included in the electrolyte in this section.

[0477] The lithium salt is not particularly limited as long as it is known to be used for this purpose, and any lithium salt can be used. Specific examples include the following: Examples thereof include lithium fluoroborate, lithium fluorophosphate, lithium tungstate, lithium carboxylate, lithium sulfonate, lithium imide, lithium methide, lithium oxalate, and fluorine-containing organic lithium salts.

[0478] Among these, from the viewpoint of improving low-temperature output characteristics, high-rate charge / discharge characteristics, impedance characteristics, high-temperature storage characteristics, cycle characteristics, etc., lithium fluoroborate salts include LiBF4; lithium fluorophosphate salts include LiPF6, Li2PO3F, and LiPO2F2; lithium sulfonate salts include LiFSO3 and CH3SO3Li; lithium imide salts include LiN(FSO2)2, LiN(FSO2)(CF3SO2), LiN(CF3SO2)2, and LiN(C2F5SO2)2; and lithium cyclic 1,2-perfluorinated lithium phosphate salts. Preferred examples of the lithium methide salt include lithium difluorooxalatoborate, lithium bis(oxalato)borate, lithium tetrafluorooxalatophosphate, lithium difluorobis(oxalato)phosphate, and lithium tris(oxalato)phosphate.

[0479] In Aspect A, in which the specific compound is Compound (A), the lithium salt is more preferably one or more selected from LiPF, LiN(FSO), and lithium bis(oxalato)borate, with LiPF being particularly preferred. Note that in Aspect A, LiFSO is excluded from the examples of the lithium salt. In Aspect B, in which the specific compound is Compound (B), the lithium salt is more preferably one or more selected from LiPF, LiN(FSO), lithium bis(oxalato)borate, and LiFSO, and particularly preferably LiPF. In Aspect B, examples of the lithium salt exclude LiPOF. In Aspect C, where the specific compound is Compound (C), the lithium salt is more preferably one or more selected from LiPF, LiN(FSO), lithium bis(oxalato)borate, and LiFSO, and particularly preferably LiPF. In Aspect C, examples of the lithium salt exclude lithium fluoroborate, lithium difluorooxalatoborate, and lithium bis(oxalato)borate. In embodiment D, where the specific compound is compound (D), the lithium salt is more preferably one or more selected from LiPF6, LiN(FSO2)2, lithium bis(oxalato)borate, and LiFSO3, and particularly preferably LiPF6. In embodiment E where the specific compound is compound (E), the lithium salt is more preferably one or more selected from LiPF6, LiN(FSO2)2, lithium bis(oxalato)borate, and LiFSO3, and particularly preferably LiPF6. In embodiment F where the specific compound is compound (F), the lithium salt is more preferably one or more selected from LiPF6, LiN(FSO2)2, lithium bis(oxalato)borate, and LiFSO3, and particularly preferably LiPF6. In embodiment G where the specific compound is compound (G), the lithium salt is more preferably one or more selected from LiPF6, LiN(FSO2)2, lithium bis(oxalato)borate and LiFSO3, and particularly preferably LiPF6. In embodiment H where the specific compound is compound (H), the lithium salt is more preferably one or more selected from LiPF6, LiN(FSO2)2, lithium bis(oxalato)borate and LiFSO3, and particularly preferably LiPF6. In the embodiment I in which the specific compound is compound (I), the lithium salt is more preferably one or more selected from LiPF6, LiN(FSO2)2, lithium bis(oxalato)borate, and LiFSO3, and particularly preferably LiPF6.

[0480] The above electrolytes may be used alone or in combination of two or more kinds in any ratio. The combination of two or more electrolytes is not particularly limited, but examples thereof include, in Embodiments A, B, D, E, F, H, and I, a combination of LiPF6 and LiN(FSO2)2; a combination of LiPF6 and LiBF4; a combination of LiPF6 and LiN(CF3SO2)2; a combination of LiBF4 and LiN(FSO2)2; and a combination of LiBF4, LiPF6, and LiN(FSO2)2. Of these, a combination of LiPF6 and LiN(FSO2)2; a combination of LiPF6 and LiBF4; and a combination of LiBF4, LiPF6, and LiN(FSO2)2 are preferred. In the embodiment C, the combination of LiPF6 and LiN(FSO2)2, the combination of LiPF6 and LiN(CF3SO2)2, etc. are mentioned. Among them, the combination of LiPF6 and LiN(FSO2)2 is preferable. In the embodiment G, among others, a combination of LiPF6 and LiN(FSO2)2; a combination of LiPF6 and LiBF4; and a combination of LiBF4, LiPF6 and LiN(FSO2)2 are preferred.

[0481] The sodium salt is not particularly limited, and examples thereof include sodium fluoroborates, sodium fluorophosphates, sodium tungstates, sodium carboxylates, sodium sulfonates, sodium imide salts, sodium methide salts, sodium oxalate salts, and fluorine-containing organic sodium salts.

[0482] Among these, from the viewpoint of improving low-temperature output characteristics, high-rate charge / discharge characteristics, impedance characteristics, high-temperature storage characteristics, cycle characteristics, etc., sodium fluoroborate salts such as NaBF4; sodium fluorophosphate salts such as NaPF6, Na2PO3F, and NaPO2F2; sodium sulfonate salts such as NaFSO3 and CH3SO3Na; sodium imide salts such as NaN(FSO2)2, NaN(FSO2)(CF3SO2), NaN(CF3SO2)2, and NaN(C2F5SO2)2; and sodium cyclic 1,2-perfluorinated sodium salts such as NaFSO3 and NaFSO4. Preferred are oroethane disulfonylimide and sodium cyclic 1,3-perfluoropropane disulfonylimide; sodium methide salts such as NaC(FSO2)3, NaC(CF3SO2)3, and NaC(C2F5SO2)3; and sodium oxalate salts such as sodium difluorooxalatoborate, sodium bis(oxalato)borate, sodium tetrafluorooxalate phosphate, sodium difluorobis(oxalate)phosphate, and sodium tris(oxalate)phosphate.

[0483] In Aspect A, where the specific compound is Compound (A), the sodium salt is more preferably one or more selected from NaPF, NaN(FSO), and sodium bis(oxalato)borate, with NaPF being particularly preferred. Note that in Aspect A, NaFSO is excluded from the examples of the sodium salt. In Aspect B, in which the specific compound is Compound (B), the sodium salt is more preferably one or more selected from NaPF, NaN(FSO), sodium bis(oxalato)borate, and NaFSO, and particularly preferably NaPF. In Aspect B, examples of the sodium salt exclude NaPOF. In Aspect C, where the specific compound is Compound (C), the sodium salt is more preferably one or more selected from NaPF, NaN(FSO), sodium bis(oxalato)borate, and NaFSO, and particularly preferably NaPF. Note that in Aspect C, examples of the sodium salt exclude sodium fluoroborate, sodium difluorooxalatoborate, and sodium bis(oxalato)borate. In embodiment D, where the specific compound is compound (D), the sodium salt is more preferably one or more selected from NaPF6, NaN(FSO2)2, sodium bis(oxalato)borate, and NaFSO3, and particularly preferably NaPF6. In embodiment E where the specific compound is compound (E), the sodium salt is more preferably one or more selected from NaPF6, NaN(FSO2)2, sodium bis(oxalato)borate, and NaFSO3, with NaPF6 being particularly preferred. In embodiment F where the specific compound is compound (F), the sodium salt is more preferably one or more selected from NaPF6, NaN(FSO2)2, sodium bis(oxalato)borate and NaFSO3, and particularly preferably NaPF6. In embodiment G where the specific compound is compound (G), the sodium salt is more preferably one or more selected from NaPF6, NaN(FSO2)2, sodium bis(oxalato)borate, and NaFSO3, with NaPF6 being particularly preferred. In embodiment H where the specific compound is compound (H), the sodium salt is more preferably one or more selected from NaPF6, NaN(FSO2)2, sodium bis(oxalato)borate and NaFSO3, with NaPF6 being particularly preferred. In embodiment I where the specific compound is compound (I), the sodium salt is more preferably one or more selected from NaPF6, NaN(FSO2)2, sodium bis(oxalato)borate and NaFSO3, with NaPF6 being particularly preferred.

[0484] The other compounds that can serve as electrolytes can be used either individually or in combination of two or more in any ratio. The combination of two or more types of other compounds that form the electrolyte is not particularly limited, and in Embodiments A, B, D, E, F, G, H, and I, examples include a combination of NaPF6 and NaN(FSO2)2, a combination of NaPF6 and NaBF4, a combination of NaPF6 and NaN(CF3SO2)2, a combination of NaBF4 and NaN(FSO2)2, and a combination of NaBF4, NaPF6, and NaN(FSO2)2. Among these, a combination of NaPF6 and NaN(FSO2)2, a combination of NaPF6 and NaBF4, and a combination of NaBF4, NaPF6 and NaN(FSO2)2 are preferred.

[0485] In the embodiment C, examples of the combination of two or more other compounds that can be used as electrolytes include a combination of NaPF6 and NaN(FSO2)2, and a combination of NaPF6 and NaN(CF3SO2)2. Among these, the combination of NaPF6 and NaN(FSO2)2 is preferred.

[0486] Examples of potassium salts include those in which Li and Na in the above lithium salts and sodium salts are substituted with potassium (K).

[0487] The total content of the electrolyte in this embodiment is not particularly limited, but from the viewpoint of ensuring that the electrical conductivity is appropriate for battery operation and that sufficient output characteristics are exhibited, it is preferably, for example, 8 to 18 mass% relative to the total amount of the electrolytic solution. Here, the total content is preferably 8 mass% or more, more preferably 8.5 mass% or more, and even more preferably 9 mass% or more, and is preferably 18 mass% or less, more preferably 17 mass% or less, and even more preferably 16 mass% or less. The electrolytes are identified and their content is measured by nuclear magnetic resonance (NMR) spectroscopy.

[0488] [1-3. Non-aqueous solvents] The electrolytic solution in this embodiment contains a non-aqueous solvent that dissolves the above-mentioned electrolyte, similar to a general non-aqueous electrolytic solution. The non-aqueous solvent used is not particularly limited as long as it dissolves the electrolyte, and known organic solvents can be used.

[0489] Examples of organic solvents include, but are not limited to, saturated cyclic carbonates, chain carbonates, chain carboxylic acid esters, cyclic carboxylic acid esters, ether compounds, and sulfone compounds. The organic solvents can be used alone or in combination of two or more in any ratio.

[0490] The combination of two or more organic solvents is not particularly limited, and examples thereof include a combination of a saturated cyclic carbonate and a chain carbonate, a combination of a saturated cyclic carbonate and a chain carboxylic acid ester, a combination of a cyclic carboxylic acid ester or a chain carbonate and a saturated cyclic carbonate, a combination of a chain carbonate and a chain carboxylic acid ester, a combination of a saturated cyclic carbonate, a chain carbonate and a chain carboxylic acid ester, etc. Among these, a combination of a saturated cyclic carbonate and a chain carbonate, and a combination of a saturated cyclic carbonate, a chain carbonate and a chain carboxylic acid ester are preferred.

[0491] [1-3-1. Saturated cyclic carbonates] Examples of saturated cyclic carbonates, which are one aspect of the non-aqueous solvent in this embodiment, include those having an alkylene group with 2 to 4 carbon atoms. From the viewpoint of improving the battery characteristics resulting from an improved degree of lithium ion dissociation, saturated cyclic carbonates having an alkylene group with 2 to 3 carbon atoms are preferably used.

[0492] Specific examples of saturated cyclic carbonates include ethylene carbonate, propylene carbonate, and butylene carbonate. Among these, ethylene carbonate or propylene carbonate is preferred, and ethylene carbonate, which is less susceptible to oxidation and reduction, is more preferred. The saturated cyclic carbonates may be used alone or in any combination and ratio of two or more.

[0493] The content of the saturated cyclic carbonate is not particularly limited and can be any amount as long as it does not significantly impair the effects of the present invention, but is usually preferably 3 to 90% by volume relative to the total amount of non-aqueous solvent in the electrolyte. Here, the content is preferably, for example, 3% by volume or more, more preferably 5% by volume or more, and is preferably, for example, 90% by volume or less, more preferably 85% by volume or less, and even more preferably 80% by volume or less. By setting the content of the saturated cyclic carbonate within this range, a decrease in electrical conductivity due to a decrease in the dielectric constant of the electrolyte can be avoided, and the large-current discharge characteristics, stability with respect to the negative electrode, and cycle characteristics of the non-aqueous electrolyte secondary battery tend to be in good ranges, and the oxidation / reduction resistance of the electrolyte and stability during high-temperature storage tend to be improved. In this specification, the volume % means the volume at 25° C. and 1 atmosphere.

[0494] [1-3-2. Chain carbonate] As the chain carbonate, which is one aspect of the non-aqueous solvent in this embodiment, for example, one having 3 to 7 carbon atoms is used, and in order to adjust the viscosity of the electrolyte solution to an appropriate range, a chain carbonate having 3 to 5 carbon atoms is preferably used.

[0495] Specific examples of the chain carbonate include dimethyl carbonate, diethyl carbonate, di-n-propyl carbonate, diisopropyl carbonate, n-propyl isopropyl carbonate, ethyl methyl carbonate, and methyl-n-propyl carbonate. Dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate are particularly preferred. The chain carbonate may be used alone or in any combination of two or more kinds in any ratio.

[0496] The content of the chain carbonate is not particularly limited, but is preferably 15 to 90% by volume relative to the total amount of non-aqueous solvent in the electrolyte. Here, the content is preferably 15% by volume or more, more preferably 20% by volume or more, and even more preferably 25% by volume or more, and is preferably 90% by volume or less, more preferably 85% by volume or less, and even more preferably 80% by volume or less. By setting the content of the chain carbonate within the above range, the viscosity of the electrolyte can be set in an appropriate range, a decrease in ionic conductivity can be suppressed, and the output characteristics of the non-aqueous electrolyte secondary battery can be easily set in a good range.

[0497] Furthermore, by combining a specific chain carbonate with ethylene carbonate in a specific content, the battery performance can be significantly improved.

[0498] For example, when dimethyl carbonate and ethyl methyl carbonate are selected as the specific chain carbonates, the content of ethylene carbonate is not particularly limited and may be any amount as long as it does not significantly impair the effects of the present invention, but is preferably 15 to 45% by volume relative to the total amount of non-aqueous solvent in the electrolyte solution. Here, the content is preferably 15% by volume or more, more preferably 20% by volume or more, and is preferably 45% by volume or less, more preferably 40% by volume or less. The content of dimethyl carbonate is preferably 20 to 50% by volume relative to the total amount of the non-aqueous solvent in the electrolyte, and the content is preferably 20% by volume or more, more preferably 30% by volume or more, and is preferably 50% by volume or less, more preferably 45% by volume or less. Furthermore, the content of ethyl methyl carbonate is preferably 20 to 50% by volume relative to the total amount of the non-aqueous solvent in the electrolytic solution, where the content is preferably 20% by volume or more, more preferably 30% by volume or more, and is preferably 50% by volume or less, more preferably 45% by volume or less. By setting each content within the above range, high temperature stability is excellent and gas generation tends to be suppressed.

[0499] [1-3-3. Chain carboxylic acid esters] Examples of the chain carboxylic acid ester, which is one aspect of the non-aqueous solvent in this embodiment, include methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, methyl valerate, methyl isobutyrate, ethyl isobutyrate, and methyl pivalate. Among these, methyl acetate, ethyl acetate, propyl acetate, and butyl acetate are preferred from the viewpoint of improving battery characteristics. Chain carboxylic acid esters in which some of the hydrogen atoms of the above-mentioned chain carboxylic acid esters are substituted with fluorine atoms can also be suitably used. Examples of such fluorine-substituted chain carboxylic acid esters include methyl trifluoroacetate, ethyl trifluoroacetate, 2,2-difluoroethyl acetate, and 2,2,2-trifluoroethyl acetate.

[0500] The content of the chain carboxylic acid ester is preferably 1 to 70% by volume relative to the total amount of nonaqueous solvent in the electrolyte. From the viewpoints of improving the electrical conductivity of the electrolyte and enhancing the large-current discharge characteristics of nonaqueous electrolyte batteries, the content is preferably 1% by volume or more, more preferably 5% by volume or more, and even more preferably 15% by volume or more. Furthermore, from the viewpoints of preventing a decrease in electrical conductivity, suppressing an increase in negative electrode resistance, and easily achieving a favorable range for the large-current discharge characteristics of nonaqueous electrolyte secondary batteries by maintaining the viscosity of the electrolyte within an appropriate range, the content is preferably 70% by volume or less, more preferably 50% by volume or less, and even more preferably 40% by volume or less.

[0501] [1-3-4. Cyclic carboxylic acid esters] Examples of the cyclic carboxylic acid ester, which is one aspect of the non-aqueous solvent in this embodiment, include γ-butyrolactone and γ-valerolactone. Among these, γ-butyrolactone is more preferred. Cyclic carboxylic acid esters in which some of the hydrogen atoms of the above-mentioned cyclic carboxylic acid esters are substituted with fluorine atoms can also be used preferably.

[0502] The content of the cyclic carboxylic acid ester is preferably 1 to 70% by volume relative to the total amount of nonaqueous solvent in the electrolyte. From the viewpoints of improving the electrical conductivity of the electrolyte and enhancing the large-current discharge characteristics of nonaqueous electrolyte secondary batteries, the content is preferably 1% by volume or more, more preferably 5% by volume or more, and even more preferably 15% by volume or more. Furthermore, from the viewpoints of preventing a decrease in electrical conductivity, suppressing an increase in negative electrode resistance, and easily achieving a favorable range for the large-current discharge characteristics of nonaqueous electrolyte secondary batteries by maintaining the viscosity of the electrolyte within an appropriate range, the content is preferably 70% by volume or less, more preferably 50% by volume or less, and even more preferably 40% by volume or less.

[0503] [1-3-5. Ether compounds] Preferred examples of the ether-based compound, which is one aspect of the non-aqueous solvent in this embodiment, include chain ethers having 3 to 10 carbon atoms, such as dimethoxymethane, diethoxymethane, ethoxymethoxymethane, ethylene glycol di-n-propyl ether, ethylene glycol di-n-butyl ether, and diethylene glycol dimethyl ether, and cyclic ethers having 3 to 6 carbon atoms, such as tetrahydrofuran, 2-methyltetrahydrofuran, 3-methyltetrahydrofuran, 1,3-dioxane, 2-methyl-1,3-dioxane, 4-methyl-1,3-dioxane, and 1,4-dioxane. Also suitable are ether-based compounds in which some of the hydrogen atoms in the above-mentioned ether-based compounds have been substituted with fluorine atoms.

[0504] Among these, dimethoxymethane, diethoxymethane, and ethoxymethoxymethane are preferred as chain ethers having 3 to 10 carbon atoms because they have a high solvation ability for lithium ions, improve ionic dissociation, have low viscosity, and provide high ionic conductivity. Furthermore, tetrahydrofuran, 1,3-dioxane, and 1,4-dioxane are preferred as cyclic ethers having 3 to 6 carbon atoms because they provide high ionic conductivity.

[0505] The content of the ether-based compound is not particularly limited and may be any amount as long as it does not significantly impair the effects of the present invention. However, it is preferably 1 to 30% by volume relative to the total amount of nonaqueous solvent in the electrolyte. Here, the content is preferably 1% by volume or more, more preferably 2% by volume or more, even more preferably 3% by volume or more, and is preferably 30% by volume or less, more preferably 25% by volume or less, and even more preferably 20% by volume or less. If the content of the ether-based compound is within the above range, it is easy to ensure the effects of improving the degree of lithium ion dissociation by the ether-based compound and improving ionic conductivity due to the reduced viscosity of the electrolyte. Furthermore, when the negative electrode active material further contains a carbon-based material in addition to a metal material, the phenomenon of chain ethers being co-inserted with lithium ions can be suppressed, thereby allowing the input / output characteristics and charge / discharge rate characteristics to be within appropriate ranges.

[0506] [1-3-6. Sulfone compounds] The sulfone compound, which is one aspect of the non-aqueous solvent in this embodiment, is not particularly limited, and may be a cyclic sulfone or a chain sulfone. In the case of cyclic sulfones, the number of carbon atoms is preferably 3 to 6, and more preferably 3 to 5. In the case of a chain sulfone, the number of carbon atoms is preferably 2 to 6, and more preferably 2 to 5. The number of sulfonyl groups in one molecule of the sulfone compound is not particularly limited, but is usually one or two.

[0507] Examples of cyclic sulfones include monosulfone compounds such as trimethylene sulfones, tetramethylene sulfones, and hexamethylene sulfones; and disulfone compounds such as trimethylene disulfones, tetramethylene disulfones, and hexamethylene disulfones. Among these, from the viewpoints of dielectric constant and viscosity, tetramethylene sulfones, tetramethylene disulfones, hexamethylene sulfones, and hexamethylene disulfones are more preferred, and tetramethylene sulfones (sulfolanes) are particularly preferred.

[0508] As the sulfolanes, sulfolane and / or sulfolane derivatives are preferred. The sulfolane derivative is preferably one in which one or more hydrogen atoms bonded to the carbon atoms constituting the sulfolane ring are substituted with a fluorine atom, an alkyl group or a fluorine-substituted alkyl group.

[0509] Among these, 2-methylsulfolane, 3-methylsulfolane, 2-fluorosulfolane, 3-fluorosulfolane, 2,3-difluorosulfolane, 2-trifluoromethylsulfolane, 3-trifluoromethylsulfolane, and the like are preferred because of their high ionic conductivity and excellent input / output characteristics.

[0510] Examples of the chain sulfone include dimethyl sulfone, ethyl methyl sulfone, diethyl sulfone, monofluoromethyl methyl sulfone, difluoromethyl methyl sulfone, trifluoromethyl methyl sulfone, pentafluoroethyl methyl sulfone, etc. Among these, dimethyl sulfone, ethyl methyl sulfone, or monofluoromethyl methyl sulfone is preferred in terms of improving the high-temperature storage stability of the electrolyte solution.

[0511] The content of the sulfone-based compound is not particularly limited and can be any amount as long as it does not significantly impair the effects of the present invention, but is preferably 0.3 to 40% by volume relative to the total amount of non-aqueous solvent in the electrolyte. Here, the content is preferably 0.3% by volume or more, more preferably 0.5% by volume or more, and even more preferably 1% by volume or more, and is preferably 40% by volume or less, more preferably 35% by volume or less, and even more preferably 30% by volume or less. If the content of the sulfone-based compound is within the above range, an electrolyte with excellent high-temperature storage stability tends to be obtained.

[0512] <2. Positive electrode> The positive electrode has a current collector and a positive electrode active material layer formed on at least a portion of the surface of the current collector. The positive electrode active material layer is not particularly limited as long as it can electrochemically absorb and release metal ions. For example, when the battery is a lithium ion secondary battery, a lithium transition metal compound can be used.

[0513] [2-1. Positive electrode active material] The following describes lithium transition metal compounds as the positive electrode active material used in the positive electrode.

[0514] [2-1-1. Lithium transition metal compounds] The lithium transition metal compound is a compound having a structure capable of desorbing and inserting lithium ions, and examples thereof include sulfides, phosphate compounds, silicate compounds, borate compounds, lithium transition metal composite oxides, etc. Among these, phosphate compounds and lithium transition metal composite oxides are preferred, and lithium transition metal composite oxides are more preferred.

[0515] Examples of lithium transition metal composite oxides include those having a spinel structure or olivine structure that allow three-dimensional diffusion of lithium ions, and those having a layered structure that allows two-dimensional diffusion of lithium ions. Among these, lithium transition metal composite oxides having a layered structure are preferred from the viewpoint of improving battery capacity.

[0516] A lithium transition metal composite oxide having a spinel structure is generally represented by the following composition formula (a). Li x’ M'2O4···(a) (In the composition formula (a), x' is 1≦x'≦1.5, and M' contains at least one transition metal element.)

[0517] Lithium transition metal composite oxides with spinel structure include LiMn2O4, LiCoMnO4, and LiNi 0.5 Mn 1.5 Examples include O4 and LiCoVO4.

[0518] A lithium transition metal composite oxide having an olivine structure is generally represented by the following composition formula (b). Li x” M” y” PO4 (b) (In formula (b), 0.8≦x″≦1.5, 0.9≦y″≦1.1, and M″ contains at least one transition metal element.)

[0519] Examples of “M” include Fe, Ni, Co, Mn, etc. Specific examples of the lithium transition metal composite oxide having an olivine structure include LiFePO4, LiMn z” Fe 1-z” PO4 (0 < z” < 1), etc.

[0520] The lithium transition metal composite oxide having a layered structure is generally represented by the following compositional formula (c). Li 1+x’’’ M’’’O2 ··· (c) (In the compositional formula (c), x’’’ satisfies -0.1 ≤ x’’’ ≤ 0.5, and M’’’ contains at least one transition metal element.)

[0521] Specific examples of the lithium transition metal composite oxide having a layered structure include LiCoO2, LiNiO2, LiNi 0.90 Co 0.05 Mn 0.05 O2, LiNi 0.85 Co 0.10 Al 0.05 O2, LiNi 0.80 Co 0.15 Al 0.05 O2, LiNi 0.33 Co 0.33 Mn 0.33 O2, Li 1.05 Ni 0.33 Co 0.33 Mn 0.33 O2, LiNi 0.5 Co 0.2 Mn 0.3 O2, Li 1.05 Ni 0.5 Co 0.2 Mn 0.3 O2, LiNi 0.6 Co 0.2 Mn 0.2 O2, LiNi 0.8 Co 0.1 Mn 0.1 O2, Li[Li 1 / 3 Mn 2 / 3 O2, and their solid solutions, etc.

[0522] Among the lithium transition metal composite oxides having a layered structure, a lithium transition metal composite oxide having a layered structure represented by the following composition formula (β) is more preferred. Li a Ni b Co c M d O2 (β) (In the composition formula (β), the numerical values ​​are 0.9≦a≦1.1, 0.5≦b≦0.98, 0.01≦c≦0.2, and 0.01≦d≦0.5, and b+c+d=1 is satisfied. M contains at least one element selected from the group consisting of Mn, Al, Mg, Zr, Fe, Ti, and Er, and is a metallic element excluding Li, Ni, and Co.)

[0523] In the above composition formula (β), M preferably contains at least one element selected from the group consisting of Mn, Al, and Zr, more preferably contains at least one of Mn and Al, and even more preferably contains Mn. By using the above compound, the structural stability of the lithium transition metal oxide is increased, and structural deterioration during repeated charge and discharge is more suitably suppressed.

[0524] In the above composition formula (β), a is 0.9 to 1.1, but is preferably 0.95 or more, more preferably 0.98 or more, and is preferably 1.1 or less, more preferably 1.05 or less. b is 0.5 to 0.98, but is preferably 0.6 or more, more preferably 0.8 or more, and is preferably 0.95 or less. c is 0.01 to 0.2, but is preferably 0.15 or less, more preferably 0.1 or less, and particularly preferably 0.05 or less. d is 0.01 to 0.5, but is preferably 0.05 or more, more preferably 0.1 or more, and is preferably 0.3 or less, more preferably 0.2 or less.

[0525] A preferred example of the lithium transition metal oxide represented by the composition formula (β) is LiNi 0.85 Co 0.10 Al 0.05 O2, LiNi 0.80 Co 0.15 Al 0.05 O2, LiNi0.70 Co 0.15 Mn 0.15 O2, LiNi 0.50 Co 0.20 Mn 0.30 O2, Li 1.05 Ni 0.50 Co 0.20 Mn 0.30 O2, LiNi 0.60 Co 0.20 Mn 0.20 O2, LiNi 0.80 Co 0.10 Mn 0.10 O2, LiNi 0.90 Co 0.05 Mn 0.05 Examples include O2. The positive electrode active material is identified and its content is measured by ICP emission spectroscopy after wet decomposition of the sample.

[0526] [2-1-2. Introduction of different elements] The lithium transition metal composite oxide of this embodiment may contain elements (foreign elements) other than the elements contained in the above-mentioned composition formulas.

[0527] [2-1-3. Surface coating] The positive electrode active material in this embodiment may have a substance (surface-adhering substance) having a different composition from the positive electrode active material attached to its surface. Examples of surface-adhering substances include oxides such as aluminum oxide, sulfates such as lithium sulfate, and carbonates such as lithium carbonate. These surface-adhering substances can be attached to the surface of the positive electrode active material by, for example, dissolving or suspending them in a solvent, adding them to the positive electrode active material by impregnation, and drying them.

[0528] The amount of the surface-attached substance is preferably 1 μmol / g to 1 mmol / g relative to the positive electrode active material, where the amount is preferably 1 μmol / g or more, more preferably 10 μmol / g or more, and is usually 1 mmol / g or less. In this specification, a positive electrode active material having the above-mentioned surface-adhering substance attached to its surface is also referred to as a "positive electrode active material."

[0529] [2-1-4. Blend] In this embodiment, the positive electrode active material may be used alone or in any combination of two or more kinds in any ratio.

[0530] [2-2. Positive electrode structure and manufacturing method] The structure and manufacturing method of the positive electrode will be described below. In this embodiment, a positive electrode using a positive electrode active material can be manufactured by a conventional method. That is, a positive electrode can be obtained by a method in which a positive electrode active material, a binder, and optionally a conductive material and a thickener are mixed in a dry state to form a sheet, which is then pressed onto a positive electrode current collector, or by a coating method in which these materials are dissolved or dispersed in a liquid medium such as an aqueous solvent or an organic solvent to form a slurry, which is then applied to a positive electrode current collector and dried to form a positive electrode active material layer on the current collector. Alternatively, for example, the positive electrode active material can be roll-formed into a sheet electrode, or compression-molded into a pellet electrode. Hereinafter, the case where the slurry is sequentially applied to the positive electrode current collector and then dried will be described.

[0531] [2-2-1. Active material content] The positive electrode comprises a current collector and a positive electrode active material layer formed on the current collector, the content of the positive electrode active material in the positive electrode active material layer being typically 80% by mass or more and 99.5% by mass or less.

[0532] [2-2-2.Conductive materials] As the conductive material, any known conductive material can be used. Specific examples include metal materials such as copper and nickel, graphite such as natural graphite and artificial graphite, carbon black such as acetylene black, and carbon-based materials such as amorphous carbon such as needle coke. One type of conductive material may be used alone, or two or more types may be used in any combination and ratio.

[0533] The conductive material is usually contained in the positive electrode active material layer in an amount of 0.01% by mass to 50% by mass.

[0534] [2-2-3. Binder] When the positive electrode active material layer is formed by a coating method, the binder used in producing the positive electrode active material layer is not particularly limited in type as long as it is a material that can be dissolved or dispersed in a liquid medium for the slurry. As the binder, for example, fluorine-based resins such as polyvinyl fluoride, polyvinylidene fluoride, and polytetrafluoroethylene; and CN group-containing polymers such as polyacrylonitrile and polyvinylidene cyanide are preferred in view of weather resistance, chemical resistance, heat resistance, flame retardancy, and the like. Also usable are mixtures, modified products, derivatives, random copolymers, alternating copolymers, graft copolymers, block copolymers, etc. The binder may be used alone or in any combination and ratio of two or more types.

[0535] When a resin is used as a binder, the weight-average molecular weight of the resin is optional as long as it does not significantly impair the effects of the present invention, but is usually preferably from 10,000 to 3,000,000. Here, the weight-average molecular weight is usually preferably 10,000 or more, more preferably 50,000 or more, and particularly preferably 100,000 or more, while usually preferably 3,000,000 or less, more preferably 950,000 or less, and particularly preferably 900,000 or less. When the molecular weight is within this range, the strength of the electrode is improved, and the electrode can be formed more smoothly.

[0536] The content of the binder in the positive electrode active material layer is usually 0.1% by mass or more and 80% by mass or less.

[0537] [2-2-4. Current collector] The material of the current collector that holds the positive electrode active material is not particularly limited, and any known material can be used. Specific examples include metal materials such as aluminum, stainless steel, nickel plating, titanium, and tantalum. Among these, aluminum is preferred.

[0538] The current collector may be in the form of a metal foil, a metal cylinder, a metal coil, a metal plate, a metal thin film, an expanded metal, a punched metal, a foamed metal, or the like. Of these, a metal foil or a metal thin film is preferred. The metal thin film may be suitably formed into a mesh shape.

[0539] When the current collector of the positive electrode is in the form of a plate or film, the thickness of the current collector is optional, but is usually 1 μm or more and 1 mm or less.

[0540] [2-2-5. Thickness of the positive electrode plate] The thickness of the positive electrode (positive electrode plate) is not particularly limited, but from the viewpoint of high capacity and high output, the thickness of the positive electrode active material layer, which is the thickness of the positive electrode plate minus the thickness of the current collector, is usually 10 μm or more and 500 μm or less on one side of the current collector. The positive electrode active material layer may be formed on one surface or both surfaces of the current collector.

[0541] [2-2-6. Electrode density] The positive electrode active material layer obtained by applying and drying the positive electrode active material together with a binder, a conductive material, etc. is preferably compacted by a hand press, a roller press, etc. in order to increase the packing density of the positive electrode active material. The electrode structure when the positive electrode active material is made into an electrode is not particularly limited, but the density of the positive electrode active material layer present on the current collector is usually 1.5 g / cm 3 More than 4.5g / cm 3 The following is the result.

[0542] [2-2-7. Surface coating of positive electrode plate] The positive electrode plate may have a substance of a different composition attached to its surface, and the substance may be the same as the surface-attached substance that may be attached to the surface of the positive electrode active material.

[0543] <3. Negative electrode> The negative electrode includes a current collector and a negative electrode active material layer formed on at least a portion of the current collector surface. The negative electrode in this embodiment includes a metal material and carbon nanotubes as active materials. Preferably, the negative electrode further includes graphite.

[0544] [3-1. Negative electrode active material] The negative electrode active material used in the negative electrode of this embodiment includes a metal material capable of electrochemically absorbing and releasing metal ions. The negative electrode active material may further contain a negative electrode active material other than the above-mentioned metal materials. There are no particular limitations on the negative electrode active material other than the metal materials, as long as it is capable of electrochemically absorbing and desorbing metal ions, preferably lithium ions.

[0545] [3-1-1. Metal materials] In this embodiment, the metallic material refers to a material containing a metallic element and / or a semi-metallic element that can be alloyed with Li. Furthermore, the metal that constitutes the metallic material refers to the metallic element and / or the semi-metallic element. Methods for confirming that metal particles correspond to the above-mentioned metal materials include identification of the metal particle phase by X-ray diffraction, observation and elemental analysis of the particle structure using an electron microscope, and elemental analysis using fluorescent X-rays.

[0546] The metal material in this embodiment may be any conventionally known material, or an alloy consisting of two or more metals may be used, and the metal particles may be alloy particles formed from two or more metal elements.

[0547] From the viewpoint of capacity and cycle life, the metal material is preferably at least one metal or a compound of the metal (metal compound) selected from the group consisting of Fe, Co, Sb, Bi, Pb, Ni, Ag, Si, Sn, Al, Zr, Cr, P, V, Mn, As, Nb, Mo, Cu, Zn, Ge, In, Ti, and W. Among these, at least one metal or a metal compound selected from the group consisting of Si, Sn, As, Sb, Al, Zn, and W is more preferable.

[0548] Examples of the metal compounds include metal oxides, metal nitrides, metal carbides, etc., which contain the metal as a constituent element. Also, oxides, nitrides, and carbides of alloys made of two or more metals may be used.

[0549] Among metal materials, at least one of Si and Si metal compounds is preferable in terms of high capacity. In this specification, Si and Si metal compounds may be collectively referred to as Si-based materials. Also, Si metal compounds are referred to as Si compounds.

[0550] Specific examples of Si compounds include Si oxides, Si nitrides, Si carbides, oxides of Si carbides and Si nitrides, etc. Also, examples of alloyed metal compounds include Li y Si(0 < y ≦ 4.4), Li 2z SiO 2+z (0 < z ≦ 2), etc.

[0551] Here, the Si oxide is represented by, for example, SiO α1 and satisfies 0 ≦ α1 < 2. The Si nitride is represented by, for example, Si3N4 or SiN α2 and satisfies 0 < α2 ≦ 1.3. The Si carbide is represented by, for example, SiC α3 and satisfies 0.9 ≦ α3 ≦ 1.1. The oxides of Si carbides and Si nitrides are represented by SiC y O z or SiN y’ O z’ and satisfy 1 ≦ y ≦ 10 and 0 ≦ z ≦ 1, or 1 ≦ y’ ≦ 10 and 0 ≦ z’ ≦ 1.

[0552] The Si-based material preferably contains at least one selected from the group consisting of Si, Si oxide, and SiC y O z (1 ≦ y ≦ 10, 0 ≦ z ≦ 1) (silicon oxycarbide). Here, SiO α1 which is a Si oxide, is preferable because it has a larger theoretical capacity compared to graphite. Also, Si, that is, amorphous Si or nano-sized Si crystals, are preferable because alkali ions such as lithium ions can easily enter and exit, making it possible to obtain a high capacity. Furthermore, SiC y O z is preferable because it has a larger theoretical capacity compared to graphite.

[0553] In this embodiment, the content of the metal material in the active material in the negative electrode is preferably 0.1 to 50% by mass. From the viewpoint of increasing the energy density of the battery, the content is preferably 0.1% by mass or more, more preferably 3% by mass or more, and even more preferably 5% by mass or more. Furthermore, from the viewpoint of balancing the capacity loss during battery operation due to deterioration specific to the metal material with the above-mentioned improvement in energy density, the content is preferably 50% by mass or less, more preferably 45% by mass or less, and even more preferably 40% by mass or less. When two or more metal materials are contained, the total content thereof is preferably within the above range.

[0554] When the metal material is in the form of particles, the average particle size (d50) is usually 0.005 μm or more and 10 μm or less from the viewpoint of cycle life. Here, the average particle size is, for example, preferably 0.005 μm or more, or may be 0.1 μm or more, or may be 1 μm or more, or preferably 10 μm or less, or may be 5 μm or less. The above average particle size is the volume-based average particle size (median diameter) determined by a laser diffraction / scattering method. When the negative electrode contains two or more metal materials, the average particle size of all of them is taken as the average particle size of the metal materials.

[0555] When the content of the specific compound in the electrolytic solution is C [mass%] and the average particle size of the metal material is D [μm], the ratio C / D is preferably 0.001 to 1000, more preferably 0.001 to 200, even more preferably 0.01 to 200 or 0.001 to 100, and even more preferably 0.01 to 100. Here, from the viewpoint of the specific compound sufficiently forming a suitable coating on the surface of the metal material, the ratio is preferably 0.001 or more, more preferably 0.01 or more. Furthermore, from the viewpoint of suppressing excessive reaction of the specific compound on the surface of the metal material, the ratio is preferably 1000 or less, more preferably 500 or less, even more preferably 200 or less, and even more preferably 100 or less. When two or more compounds are contained as the specific compound, the content C [mass %] means the total content of the specific compounds.

[0556] [3-1-2. Carbon-based materials] In addition to the above-mentioned metal materials, the negative electrode active material in this embodiment may be a carbon-based material, a lithium-containing metal composite oxide material, or a mixture thereof. Among these, carbon-based materials, metal materials, and mixtures of metal materials and carbon-based materials are preferred because of their excellent cycle characteristics and safety, as well as excellent continuous charging characteristics. As the negative electrode active material, one type of metal material may be used alone, or two or more types may be used in any combination.

[0557] The carbon-based material is preferably graphite, and more specifically, natural graphite, artificial graphite, amorphous carbon, carbon-coated graphite, graphite-coated graphite, and resin-coated graphite are mentioned. Of these, artificial graphite and natural graphite are preferred. One type of carbon-based material may be used alone, or two or more types may be used in any combination and ratio.

[0558] Examples of natural graphite include scaly graphite, flake graphite, and / or graphite particles obtained by subjecting such graphite to treatment such as spheroidization or densification. Among these, spherical or ellipsoidal graphite particles that have been subjected to spheroidization treatment are particularly preferred from the viewpoint of particle packing properties or charge / discharge rate characteristics. The average particle size (d50) of the graphite particles is usually 1 μm or more and 100 μm or less. Here, the average particle size (d50) is the volume-based average particle size (median size) determined by a laser diffraction / scattering method.

[0559] [3-1-3. Physical properties of carbon-based materials] The carbonaceous material as the negative electrode active material preferably satisfies at least one of the characteristics such as physical properties and shape shown in the following items (1) to (4), and more preferably satisfies several items at the same time. (1) X-ray diffraction parameters The d value (interlayer distance) of the lattice plane (002 plane) of the carbon-based material determined by X-ray diffraction using the Gakushin method is 0.335 nm or more and 0.360 nm or less. The crystallite size (Lc) of the carbon-based material determined by X-ray diffraction using the Gakushin method is 1.0 nm or more. (2) Volume-based average particle size The volume-based average particle size of the carbon-based material is the volume-based average particle size (median diameter) determined by a laser diffraction / scattering method, and is 1 μm or more and 100 μm or less. (3) Raman R value, Raman half-width The Raman R value of the carbon-based material is a value measured using argon ion laser Raman spectroscopy, and is 0.01 or more and 1.5 or less. In addition, the 1580 cm -1 The Raman half-width in the vicinity is not particularly limited, but is, for example, 10 cm -1 More than 100cm -1 The following is the result. (4) BET specific surface area The BET specific surface area of ​​a carbon-based material is the value of the specific surface area measured using the BET method, and is calculated based on the surface area of ​​the carbon-based material measured using the BET method. 2 ·g -1 More than 100m 2 ·g -1 The following is the result.

[0560] The negative electrode active material may contain two or more carbonaceous materials with different properties, where the properties refer to one or more characteristics selected from the group consisting of X-ray diffraction parameters, volume-based average particle size, Raman R value, Raman half-width, and BET specific surface area, as shown in (1) to (4) above.

[0561] Examples of containing two or more carbon-based materials with different properties include a case where the volume-based particle size distribution is not symmetrical about the median diameter, a case where two or more carbon-based materials with different Raman R values ​​are contained, and a case where two or more carbon-based materials with different X-ray parameters are contained.

[0562] [3-1-4. Mixture of metal particles and graphite particles] The negative electrode active material in this embodiment may contain metal particles and graphite particles, which may be a mixture in which the metal particles and the graphite particles are mixed in a state of independent particles, or a composite in which the metal particles are present on the surface or inside of the graphite particles.

[0563] In this specification, the composite (also referred to as composite particle) is not particularly limited as long as it is a particle containing a metal material particle and a graphite particle, but is preferably a particle in which a metal material particle and a graphite particle are integrated by physical and / or chemical bonding.

[0564] A more preferred form is one in which the metal material particles and graphite particles are dispersed within the particles to such an extent that each solid component is present at least on the surface of the composite particle and inside the bulk, and the graphite particles are present to integrate them by physical and / or chemical bonds. A more specific preferred embodiment is a composite composed of at least metal particles and graphite particles, characterized in that the graphite particles, preferably natural graphite, have a curved, folded structure, and the metal particles are present in gaps within the curved, folded structure. The gaps may be voids, or may contain a substance that buffers the expansion and contraction of the metal particles, such as amorphous carbon, graphite, or resin.

[0565] The content of the metal particles relative to the total of the metal particles and graphite particles is preferably 0.1 to 99% by mass. From the viewpoint of obtaining sufficient capacity, the content is preferably 0.1% by mass or more, more preferably 1% by mass or more, even more preferably 2% by mass or more, even more preferably 3% by mass or more, and particularly preferably 5% by mass or more. From the same viewpoint, the content is preferably 99% by mass or less, more preferably 60% by mass or less, even more preferably 55% by mass or less, even more preferably 50% by mass or less, particularly preferably 40% by mass or less, and most preferably 35% by mass or less.

[0566] [3-1-5. Lithium-containing metal composite oxide materials] The lithium-containing metal composite oxide material used as the negative electrode active material is not particularly limited as long as it is capable of absorbing and releasing lithium ions. Specifically, from the viewpoint of high current density charge / discharge characteristics, a lithium-containing metal composite oxide material containing titanium is preferred, a composite oxide of lithium and titanium (hereinafter sometimes abbreviated as "lithium titanium composite oxide") is more preferred, and a lithium titanium composite oxide having a spinel structure is particularly preferred from the viewpoint of significantly reducing output resistance.

[0567] Furthermore, the lithium and / or titanium of the lithium titanium composite oxide may be substituted with another metal element, for example, at least one element selected from the group consisting of Al, Ga, Cu, and Zn.

[0568] As a lithium titanium composite oxide, Li 4 / 3 Ti 5 / 3 O4, Li1Ti2O4 and Li 4 / 5 Ti 11 / 5 O4 is preferred. In addition, examples of lithium titanium composite oxides in which part of lithium and / or titanium is substituted with other elements include Li 4 / 3 Ti 4 / 3 Al 1 / 3 O4 is also preferred.

[0569] [3-2. Carbon nanotubes] The negative electrode in this embodiment contains carbon nanotubes in addition to a metal material as an active material. Carbon nanotubes (CNTs) are substances made solely of carbon, with a structure in which a sheet of benzene rings, each of which is arranged in a hexagonal shape and all adjacent to each other on a plane, is rolled into a cylinder. The diameter of the cylinder is nanometer-sized.

[0570] CNTs are divided into "single-walled carbon nanotubes" and "multi-walled carbon nanotubes" based on their structure. Single-walled carbon nanotubes are called SWCNTs (single-walled nanotubes) because they consist of only one tube. On the other hand, multi-walled carbon nanotubes are those with multiple tubes nested within each other, and are called MWCNTs (multi-walled nanotubes).

[0571] In this embodiment, a metal material is used as the negative electrode active material, and from the viewpoint of suitably improving cycle characteristics, it is preferable that the negative electrode active material further contains CNTs, and more preferably SWCNTs. The above effect is more effective when the metal material is Si or a Si compound.

[0572] The proportion of SWCNTs in the total CNTs is preferably 60 to 100%. From the viewpoint of obtaining a sufficient effect of improving cycle characteristics, the proportion is preferably 60% or more, more preferably 70% or more, even more preferably 80% or more, even more preferably 90% or more, and particularly preferably 95% or more. The proportion may be 100%, i.e., composed solely of SWCNTs, or it may be less than 100%. Within this range, a sufficient effect of improving cycle characteristics can be obtained.

[0573] The above-mentioned ratio of SWCNTs to all CNTs refers to the ratio of the number of SWCNTs to all CNTs. First, the presence of CNTs in the negative electrode can be confirmed, for example, by a scanning electron microscope image of the negative electrode.

[0574] Then, the proportion of the SWCNTs contained in the negative electrode is determined by the following method. An image of the negative electrode is obtained using a scanning electron microscope. Several CNTs are randomly selected and observed in the image to determine the number of SWCNTs, and the ratio of the number of SWCNTs to the total number of CNTs selected is calculated.

[0575] The CNT content relative to the total amount of the negative electrode active material is preferably 0.01 to 1.0% by mass. From the viewpoint of obtaining a sufficient effect of improving cycle characteristics, the content is preferably 0.01% by mass or more, more preferably 0.05% by mass or more. Furthermore, from the viewpoint of suppressing an increase in side reactions due to an increase in the negative electrode surface area, the content is preferably 1.0% by mass or less, more preferably 0.75% by mass or less, even more preferably 0.5% by mass or less, even more preferably 0.4% by mass or less, and particularly preferably 0.3% by mass or less. The total amount of the negative electrode active material does not include the CNT content.

[0576] The diameter of the CNT is preferably 0.1 to 30.0 nm, more preferably 0.1 to 20.0 nm, even more preferably 0.1 to 10.0 nm, particularly preferably 0.5 to 5.0 nm, and most preferably 0.5 to 3.0 nm. Here, from the viewpoint that the CNTs interact favorably with the metal material active material, favorably forming a reaction field between the specific compound in the electrolyte and the metal material active material, and as a result obtaining a sufficient effect of improving cycle characteristics, the diameter is preferably 0.1 nm or more, more preferably 0.5 nm or more, and is preferably 30.0 nm or less, more preferably 20.0 nm or less, even more preferably 10.0 nm or less, even more preferably 5.0 nm, and particularly preferably 3.0 nm or less. The above effect is more pronounced when the metal material active material is a Si-based active material such as Si or a Si compound. When the CNT is an MWCNT, the above diameter refers to the diameter of the CNT located at the outermost shell.

[0577] In this embodiment, the diameter of the CNT is determined by the following method. 1: Obtain an image of the CNT (approximately 10 fields of view) at an appropriate magnification using a scanning electron microscope. Randomly select and observe multiple CNTs in the image, and measure their diameter. 2: The RBM (diametric expansion and contraction mode) peak of CNTs is measured by Raman spectroscopy. This peak is on the low wavenumber side (100-300 cm -1 ) and the peak appears at the peak position ω(cm -1 ) has the following relationship with the CNT diameter R (nm), so the diameter is calculated using the relationship (Z). R=248 / ω (Z)

[0578] When the content of the specific compound in the electrolyte solution is C [mass %] and the diameter of the CNT is R [nm], the ratio C / R is preferably 0.0033 to 10, more preferably 0.033 to 10, or 0.0033 to 2, even more preferably 0.033 to 2, and still more preferably 0.033 to 1. This range is preferable because the specific compound can react suitably not only on the surface of the active material but also on the surface of the CNT. The above ratio is preferably 0.0033 or more, more preferably 0.033 or more, and is preferably 10 or less, more preferably 2 or less, and even more preferably 1 or less. When the CNTs are SWCNTs, it is more preferable that the above ratio range is satisfied.

[0579] In this embodiment, the average particle size of the metal material serving as the negative electrode active material is preferably larger than the diameter of the CNTs, since this ensures good contact between the metal material and the CNTs and increases the electrical conductivity of the negative electrode active material layer. The difference between the average particle size and the diameter is preferably 1 to 10,000 nm, more preferably 5 to 6,000 nm. Here, the difference may be 1 nm or more, 5 nm or more, or 10,000 nm or less, or 6,000 nm or less. Here, it is more preferable that the metal material is a Si-based active material and the CNT is a SWCNT.

[0580] The length of the CNT is preferably 1.0 to 100.0 μm, more preferably 5.0 to 20.0 μm. Here, the length is preferably 1.0 μm or more, more preferably 5.0 μm or more, and is preferably 100.0 μm or less, more preferably 20.0 μm or less. When the length of the CNT is within the above range, the CNT interacts favorably with the metal material active material, thereby favorably forming a reaction field between the specific compound in the electrolyte and the metal material active material. This can provide a sufficient effect of improving cycle characteristics. Here, it is more preferable that the metal material is a Si-based active material and the CNT is a SWCNT.

[0581] [3-3. Negative electrode structure and manufacturing method] The negative electrode may be produced by any known method as long as it does not significantly impair the effects of the present invention. For example, the negative electrode active material can be prepared by adding a binder, a liquid medium such as an aqueous solvent or an organic solvent, and, if necessary, a thickener, a conductive material, a filler, and the like to the negative electrode active material to form a slurry, which is then applied to a current collector, dried, and pressed to form a negative electrode active material layer.

[0582] [3-3-1.Negative electrode active material content] The negative electrode comprises a current collector and a negative electrode active material layer formed on the current collector, the content of the negative electrode active material in the negative electrode active material layer being typically 80% by mass or more and 99.5% by mass or less.

[0583] [3-3-2. Electrode density] The negative electrode active material layer obtained by applying and drying the negative electrode active material, optionally together with a binder, a thickener, etc., is preferably compacted by a hand press, a roller press, etc. to increase the packing density of the negative electrode active material.

[0584] There are no particular restrictions on the electrode structure when the negative electrode active material is made into an electrode, but the density of the negative electrode active material layer on the current collector is usually 1 g cm -3 More than 2.2g cm -3 The following is the result.

[0585] [3-3-3. Thickener] A thickener is typically used to adjust the viscosity of the slurry. The thickener is not particularly limited, but specific examples include carboxymethyl cellulose and its salts, methyl cellulose, hydroxymethyl cellulose, ethyl cellulose, polyvinyl alcohol, etc. These may be used alone or in any combination and ratio of two or more.

[0586] When a thickener is used, the ratio of the thickener to the negative electrode active material is usually 0.1% by mass or more and 5% by mass or less.

[0587] [3-3-4. Binder] The binder for binding the negative electrode active material is not particularly limited as long as it is a material that is stable in the non-aqueous electrolyte solution and the liquid medium used in producing the electrode. Specific examples include rubbery polymers such as SBR (styrene-butadiene rubber), isoprene rubber, butadiene rubber, fluororubber, NBR (acrylonitrile-butadiene rubber), and ethylene-propylene rubber; and fluorine-based polymers such as polyvinylidene fluoride, polytetrafluoroethylene, and tetrafluoroethylene-ethylene copolymer. These may be used alone or in any combination and ratio of two or more.

[0588] The ratio of the binder to the negative electrode active material is usually 0.1 mass % or more and 20 mass % or less. In particular, when the binder contains a rubber-like polymer such as SBR as a main component, the ratio of the binder to the negative electrode active material is preferably 0.1% by mass or more and 5% by mass or less. Furthermore, when the binder contains a fluorine-based polymer, such as polyvinylidene fluoride, as a main component, the ratio of the binder to the negative electrode active material is preferably 1% by mass or more and 15% by mass or less.

[0589] [3-3-5. Current collector] Any known current collector can be used to support the negative electrode active material. Examples of the negative electrode current collector include metal materials such as aluminum, copper, nickel, stainless steel, and nickel-plated steel, but copper is particularly preferred from the standpoints of ease of processing and cost.

[0590] The negative electrode current collector may be in the form of a metal foil, a metal cylinder, a metal coil, a metal plate, a metal thin film, an expanded metal, a punched metal, a foamed metal, or the like. Of these, a metal foil or a metal thin film is preferred. The metal foil or the metal thin film may be formed into a mesh as appropriate.

[0591] When the negative electrode current collector is in the form of a plate or film, the thickness of the current collector is not limited, but is usually 1 μm or more and 1 mm or less.

[0592] [3-3-6. Thickness of negative electrode plate] The thickness of the negative electrode (also called "negative electrode plate") is designed to match the positive electrode used and is not particularly limited, but the thickness of the negative electrode active material layer, calculated by subtracting the thickness of the current collector from the thickness of the negative electrode material, is usually 15 μm or more and 300 μm or less.

[0593] [3-3-7. Surface coating of negative electrode plate] The negative electrode plate may have a surface-attached substance with a different composition from the negative electrode active material attached to its surface, such as an oxide such as aluminum oxide, a sulfate such as lithium sulfate, or a carbonate such as lithium carbonate.

[0594] <4. Separator> A separator is usually placed between the positive electrode and the negative electrode to prevent short circuits, and in this case, the electrolyte is usually impregnated into the separator before use. There are no particular restrictions on the material or shape of the separator, and any known material can be used as long as it does not significantly impair the effects of the present invention.

[0595] <5.Battery design> [5-1. Electrode group] The electrode group may have either a laminated structure in which the positive electrode plate and the negative electrode plate are sandwiched between the separator, or a structure in which the positive electrode plate and the negative electrode plate are spirally wound with the separator sandwiched between them. The ratio of the volume of the electrode group to the internal volume of the battery (electrode group occupancy rate) is usually 40% or more and 90% or less.

[0596] [5-2. Current collection structure] When the electrode group has the aforementioned laminated structure, a structure in which the metal core portions of each electrode layer are bundled and welded to a terminal is preferably used. A structure in which multiple terminals are provided within the electrode to reduce resistance is also preferably used. When the electrode group has the aforementioned wound structure, the internal resistance can be reduced by providing multiple lead structures on each of the positive electrode and negative electrode and bundling them to a terminal.

[0597] [5-3.Protection elements] As protective elements, PTC (Positive Temperature Coefficient) elements whose resistance increases with heat generation due to excessive current, thermal fuses, thermistors, and valves (current cut-off valves) that cut off the current flowing in the circuit due to a sudden increase in the internal pressure or temperature of the battery when abnormal heat is generated can be used. It is preferable to select the protective element so that it will not operate under normal high current use, and it is more preferable to design it so that abnormal heat generation or thermal runaway does not occur even without the protective element.

[0598] [5-4. Exterior body] The battery according to this embodiment is usually constructed by housing the above-mentioned electrolyte, negative electrode, positive electrode, separator, etc. in an exterior body (exterior case). There are no limitations on this exterior body, and any known exterior body can be used as long as it does not significantly impair the effects of the present invention.

[0599] The material of the exterior case is not particularly limited as long as it is stable against the electrolyte solution used, but from the viewpoint of weight reduction, metal such as aluminum or an aluminum alloy, or a laminate film is preferably used.

[0600] Examples of exterior cases using the above metals include those in which metals are welded together by laser welding, resistance welding, or ultrasonic welding to form a sealed, airtight structure, and those in which the above metals are used via a resin gasket to form a crimped structure.

[0601] [5-5. Shape] The shape of the exterior case of the battery according to this embodiment may also be any shape, such as cylindrical, rectangular, laminated, coin-shaped, large, or the like.

[0602] [5-6. Battery manufacturing method] The battery according to this embodiment can be manufactured by combining the above-described components by a conventionally known method.

[0603] One aspect of the method for manufacturing a battery according to this embodiment includes the steps of housing the positive electrode and the negative electrode in a container, and injecting an electrolyte into the container. The negative electrode contains a metal material as an active material and carbon nanotubes, and the electrolytic solution contains an electrolyte, a non-aqueous solvent, and a specific compound.

[0604] The positive electrode, negative electrode, and electrolyte may be the same as those described above in <2. Positive electrode>, <3. Negative electrode>, and <1. Electrolyte>, and the preferred embodiments are also the same. A separator may also be used optionally, and in that case, the separator described above in <4. Separator> may be used, and the preferred embodiments are also the same.

[0605] [5-7.Applications] The battery according to this embodiment is a non-aqueous electrolyte secondary battery, preferably an alkali ion secondary battery, and more preferably a lithium ion secondary battery. The battery according to this embodiment is also suitable as a high-output power source, and is more preferably mounted on vehicles, such as electric vehicles and hybrid vehicles. [Example]

[0606] EXAMPLES The present invention will be explained in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples.

[0607] "Aspect A" <Compound> The compounds used in the present examples and comparative examples are shown below.

[0608] A compound represented by general formula (A): Lithium fluorosulfonate (Compound 1A) Lithium methyl sulfate (Compound 2A)

[0609] Carbon nanotubes CNT-1: diameter 1.3nm, SWCNT CNT-2: Diameter 8~15nm, MWCNT

[0610] Example 1A [Preparation of electrolyte] Under a dry argon atmosphere, thoroughly dried LiPF6 was dissolved in a mixture of ethylene carbonate, ethyl methyl carbonate, and diethyl carbonate (volume ratio 3:4:3) to give an electrolyte solution concentration of 1.2 mol / L. Vinylene carbonate was then added to the electrolyte solution to give a concentration of 0.5 mass%. This electrolyte solution was designated the "reference electrolyte solution." Compound 1A was added to this reference electrolyte solution to give a content of 1 mass % to prepare an electrolyte solution. Here, the "content" refers to the content (mass %) when the entire electrolyte solution is taken as 100 mass %.

[0611] [Preparation of positive electrode] LiNi as the positive electrode active material 0.70 Co 0.15 Mn 0.15 90 parts by weight of O2, 7 parts by weight of carbon black as a conductive material, and 3 parts by weight of polyvinylidene fluoride as a binder were mixed in N-methylpyrrolidone to form a slurry, which was then applied to one side of a 15 μm thick aluminum foil, dried, and roll-pressed in a press to form a positive electrode.

[0612] [Preparation of negative electrode] Graphite and SiO were mixed in a 95:5 mass ratio as the negative electrode active material. 96.65 parts by mass of this negative electrode active material, 0.05 parts by mass of CNT-1 as a conductive material, 1.3 parts by mass of sodium carboxymethyl cellulose as a thickener, and 2 parts by mass of styrene butadiene rubber as a binder were mixed in water to form a slurry. This was applied to one side of a 10 μm thick copper foil, dried, and roll-pressed in a press to form a negative electrode. The average particle size of SiO was 4.9 μm.

[0613] [Battery manufacturing] The positive electrode, negative electrode, and polyolefin separator were stacked in this order, and the resulting battery element was wrapped in an aluminum laminate film, the electrolyte solution was poured into the battery, and the battery was vacuum-sealed to prepare a laminated nonaqueous electrolyte secondary battery.

[0614] Example 2A A battery was produced in the same manner as in Example 1A, except that in preparing the electrolyte solution, Compound 1A was added to the reference electrolyte solution so that the content thereof became 0.01% by mass.

[0615] Example 3A A battery was produced in the same manner as in Example 1A, except that in the preparation of the negative electrode, CNT-2 was used instead of CNT-1 as the conductive material.

[0616] Example 4A A battery was produced in the same manner as in Example 1A, except that in preparing the electrolyte solution, Compound 2A was added to the reference electrolyte solution so that the content was 0.4 mass %.

[0617] Example 5A A battery was produced in the same manner as in Example 3A, except that in the preparation of the negative electrode, CNT-2 was used instead of CNT-1 as the conductive material.

[0618] <Comparative Example 1A> A battery was produced in the same manner as in Example 1A, except that in preparing the electrolyte solution, the reference electrolyte solution was used as it was, and in producing the negative electrode, no conductive material was used, and the negative electrode was produced by the following method. [Preparation of negative electrode] A negative electrode was produced in the same manner as in Example 1A, except that no conductive material was used, and 96.7 parts by mass of the negative electrode active material, 1.3 parts by mass of sodium carboxymethyl cellulose as a thickener, and 2 parts by mass of styrene butadiene rubber as a binder were mixed in water to form a slurry.

[0619] <Comparative example 2A> A battery was produced in the same manner as in Example 1A, except that the same negative electrode as in Comparative Example 1A was used.

[0620] <Comparative example 3A> A battery was produced in the same manner as in Example 2A, except that the same negative electrode as in Comparative Example 1A was used.

[0621] <Comparative example 4A> A battery was produced in the same manner as in Example 1A, except that the reference electrolyte was used as it was in preparing the electrolyte.

[0622] <Comparative example 5A> A battery was produced in the same manner as in Example 2A, except that the reference electrolyte was used as it was in preparing the electrolyte.

[0623] Mode B <Compound> The compounds used in the present examples and comparative examples are shown below.

[0624] Difluorophosphate anion-containing compound (B): Lithium difluorophosphate (Compound 1B)

[0625] Carbon nanotubes CNT-1: diameter 1.3nm, SWCNT CNT-2: Diameter 8~15nm, MWCNT

[0626] Example 1B [Preparation of electrolyte] Under a dry argon atmosphere, thoroughly dried LiPF6 was dissolved in a mixture of ethylene carbonate, ethyl methyl carbonate, and diethyl carbonate (volume ratio 3:4:3) to give an electrolyte solution concentration of 1.2 mol / L. Vinylene carbonate was then added to the electrolyte solution to give a concentration of 0.5 mass%. This electrolyte solution was designated the "reference electrolyte solution." Compound 1B was added to this reference electrolyte solution to give a content of 1 mass % to prepare an electrolyte solution. Here, the "content" refers to the content (mass %) when the entire electrolyte solution is taken as 100 mass %.

[0627] The preparation of the positive electrode, the preparation of the negative electrode, and the production of the battery were respectively similar to [Preparation of the positive electrode], [Preparation of the negative electrode], and [Production of the battery] in <Example 1A> of <<Aspect A>> above, to prepare a laminate-type nonaqueous electrolyte secondary battery.

[0628] Example 2B A battery was produced in the same manner as in Example 1B, except that in the preparation of the negative electrode, CNT-2 was used instead of CNT-1 as the conductive material.

[0629] <Comparative example 1B> A battery was produced in the same manner as in Example 1B, except that in preparing the electrolyte solution, the reference electrolyte solution was used as it was, and in producing the negative electrode, no conductive material was used, and the negative electrode was produced by the following method. [Preparation of negative electrode] A negative electrode was produced in the same manner as in Example 1B, except that no conductive material was used, and 96.7 parts by mass of the negative electrode active material, 1.3 parts by mass of sodium carboxymethyl cellulose as a thickener, and 2 parts by mass of styrene butadiene rubber as a binder were mixed in water to form a slurry.

[0630] <Comparative Example 2B> A battery was produced in the same manner as in Example 1B, except that the same negative electrode as in Comparative Example 1B was used.

[0631] <Comparative example 3B> A battery was produced in the same manner as in Example 1B, except that the reference electrolyte was used as it was in preparing the electrolyte.

[0632] <Comparative example 4B> A battery was produced in the same manner as in Example 2B, except that the reference electrolyte was used as it was in preparing the electrolyte.

[0633] <<Aspect C>> <Compound> The compounds used in the present examples and comparative examples are shown below.

[0634] Compound (C): Lithium tetrafluoroborate (Compound 1C)

[0635] Carbon nanotubes CNT-1: diameter 1.3nm, SWCNT CNT-2: Diameter 8~15nm, MWCNT

[0636] Example 1C [Preparation of electrolyte] Under a dry argon atmosphere, thoroughly dried LiPF6 was dissolved in a mixture of ethylene carbonate, ethyl methyl carbonate, and diethyl carbonate (volume ratio 3:4:3) to give an electrolyte solution concentration of 1.2 mol / L. Vinylene carbonate was then added to the electrolyte solution to give a concentration of 0.5 mass%. This electrolyte solution was designated the "reference electrolyte solution." Compound 1C was added to this reference electrolyte solution to give a content of 1 mass % to prepare an electrolyte solution. Here, the "content" refers to the content (mass %) when the entire electrolyte solution is taken as 100 mass %.

[0637] The preparation of the positive electrode, the preparation of the negative electrode, and the production of the battery were respectively similar to [Preparation of the positive electrode], [Preparation of the negative electrode], and [Production of the battery] in <Example 1A> of <<Aspect A>> above, to prepare a laminate-type nonaqueous electrolyte secondary battery.

[0638] Example 2C A battery was produced in the same manner as in Example 1C, except that in the preparation of the negative electrode, CNT-2 was used instead of CNT-1 as the conductive material.

[0639] <Comparative example 1C> A battery was produced in the same manner as in Example 1C, except that in preparing the electrolyte solution, the standard electrolyte solution was used as it was, and in producing the negative electrode, no conductive material was used, and the negative electrode was produced by the following method. [Preparation of negative electrode] A negative electrode was produced in the same manner as in Example 1C, except that no conductive material was used, and 96.7 parts by mass of the negative electrode active material, 1.3 parts by mass of sodium carboxymethyl cellulose as a thickener, and 2 parts by mass of styrene butadiene rubber as a binder were mixed in water to form a slurry.

[0640] <Comparative Example 2C> A battery was produced in the same manner as in Example 1C, except that the same negative electrode as in Comparative Example 1C was used.

[0641] <Comparative example 3C> A battery was produced in the same manner as in Example 1C, except that the reference electrolyte was used as it was in preparing the electrolyte.

[0642] Comparative Example 4C A battery was produced in the same manner as in Example 2C, except that the reference electrolyte was used as it was in preparing the electrolyte.

[0643] <<Aspect D>> <Compound> The compounds used in the present examples and comparative examples are shown below.

[0644] Isocyanate compound (D): Compound 1D or Compound 2D represented by the following formula:

[0645] [ka]

[0646] Carbon nanotubes CNT-1: diameter 1.3nm, SWCNT CNT-2: Diameter 8~15nm, MWCNT

[0647] Example 1D [Preparation of electrolyte] Under a dry argon atmosphere, thoroughly dried LiPF6 was dissolved in a mixture of ethylene carbonate, ethyl methyl carbonate, and diethyl carbonate (volume ratio 3:4:3) to give an electrolyte solution concentration of 1.2 mol / L. Vinylene carbonate was then added to the electrolyte solution to give a concentration of 0.5 mass%. This electrolyte solution was designated the "reference electrolyte solution." Compound 1D was added to this reference electrolyte solution to a content of 0.5% by mass to prepare an electrolyte solution. Here, the "content" refers to the content (% by mass) when the entire electrolyte solution is taken as 100% by mass.

[0648] The preparation of the positive electrode, the preparation of the negative electrode, and the production of the battery were respectively similar to [Preparation of the positive electrode], [Preparation of the negative electrode], and [Production of the battery] in <Example 1A> of <<Aspect A>> above, to prepare a laminate-type nonaqueous electrolyte secondary battery.

[0649] Example 2D A battery was produced in the same manner as in Example 1D, except that in preparing the electrolyte solution, compound 2D was used instead of compound 1D.

[0650] <Examples 3D and 4D> Batteries were produced in the same manner as in Example 1D or Example 2D, except that in the preparation of the negative electrode, CNT-2 was used instead of CNT-1 as the conductive material.

[0651] <Comparative Example 1D> A battery was produced in the same manner as in Example 1D, except that in preparing the electrolyte solution, the reference electrolyte solution was used as it was, and in producing the negative electrode, no conductive material was used, and the negative electrode was produced by the following method. [Preparation of negative electrode] A negative electrode was produced in the same manner as in Example 1D, except that no conductive material was used, and 96.7 parts by mass of the negative electrode active material, 1.3 parts by mass of sodium carboxymethyl cellulose as a thickener, and 2 parts by mass of styrene butadiene rubber as a binder were mixed in water to form a slurry.

[0652] <Comparative example 2D, 3D> A battery was produced in the same manner as in Example 1D or Example 2D, except that the same negative electrode as in Comparative Example 1D was used.

[0653] <Comparative examples 4D and 5D> In preparing the electrolyte solution, a battery was produced in the same manner as in Example 1D or Example 2D, except that the reference electrolyte solution was used as it was.

[0654] "Aspect E" <Compound> The compounds used in the present examples and comparative examples are shown below.

[0655] Compound represented by general formula (E): Compound 1E represented by the following formula:

[0656] [ka]

[0657] Carbon nanotubes CNT-1: diameter 1.3nm, SWCNT CNT-2: Diameter 8~15nm, MWCNT

[0658] Example 1E [Preparation of electrolyte] Under a dry argon atmosphere, thoroughly dried LiPF6 was dissolved in a mixture of ethylene carbonate, ethyl methyl carbonate, and diethyl carbonate (volume ratio 3:4:3) to give an electrolyte solution concentration of 1.2 mol / L. Vinylene carbonate was then added to the electrolyte solution to give a concentration of 0.5 mass%. This electrolyte solution was designated the "reference electrolyte solution." Compound 1E was added to this reference electrolyte solution to a content of 0.5% by mass to prepare an electrolyte solution. Here, the "content" refers to the content (% by mass) when the entire electrolyte solution is taken as 100% by mass.

[0659] The preparation of the positive electrode, the preparation of the negative electrode, and the production of the battery were respectively similar to [Preparation of the positive electrode], [Preparation of the negative electrode], and [Production of the battery] in <Example 1A> of <<Aspect A>> above, to prepare a laminate-type nonaqueous electrolyte secondary battery.

[0660] Example 2E A battery was produced in the same manner as in Example 1E, except that in the preparation of the negative electrode, CNT-2 was used instead of CNT-1 as the conductive material.

[0661] <Comparative Example 1E> A battery was produced in the same manner as in Example 1E, except that in preparing the electrolyte solution, the standard electrolyte solution was used as it was, and in producing the negative electrode, no conductive material was used, and the negative electrode was produced by the following method. [Preparation of negative electrode] A negative electrode was produced in the same manner as in Example 1E, except that no conductive material was used, and 96.7 parts by mass of the negative electrode active material, 1.3 parts by mass of sodium carboxymethyl cellulose as a thickener, and 2 parts by mass of styrene butadiene rubber as a binder were mixed in water to form a slurry.

[0662] <Comparative Example 2E> A battery was produced in the same manner as in Example 1E, except that the same negative electrode as in Comparative Example 1E was used.

[0663] <Comparative example 3E> A battery was produced in the same manner as in Example 1E, except that the reference electrolyte was used as it was in preparing the electrolyte.

[0664] <Comparative example 4E> A battery was produced in the same manner as in Example 2E, except that the reference electrolyte was used as it was in preparing the electrolyte.

[0665] Mode F <Compound> The compounds used in the present examples and comparative examples are shown below.

[0666] Compound represented by general formula (F): Compound 1F or Compound 2F represented by the following formula:

[0667] [ka]

[0668] Carbon nanotubes CNT-1: diameter 1.3nm, SWCNT CNT-2: Diameter 8~15nm, MWCNT

[0669] Example 1F [Preparation of electrolyte] Under a dry argon atmosphere, thoroughly dried LiPF6 was dissolved in a mixture of ethylene carbonate, ethyl methyl carbonate, and diethyl carbonate (volume ratio 3:4:3) to give an electrolyte solution concentration of 1.2 mol / L. Vinylene carbonate was then added to the electrolyte solution to give a concentration of 0.5 mass%. This electrolyte solution was designated the "reference electrolyte solution." Compound 1F was added to this reference electrolyte solution to give a content of 2 mass % to prepare an electrolyte solution. Here, "content" refers to the content (mass %) when the entire electrolyte solution is taken as 100 mass %.

[0670] The preparation of the positive electrode, the preparation of the negative electrode, and the production of the battery were respectively similar to [Preparation of the positive electrode], [Preparation of the negative electrode], and [Production of the battery] in <Example 1A> of <<Aspect A>> above, to prepare a laminate-type nonaqueous electrolyte secondary battery.

[0671] Example 2F A battery was produced in the same manner as in Example 1F, except that in preparing the electrolyte solution, compound 2F was used instead of compound 1F.

[0672] <Examples 3F and 4F> Batteries were produced in the same manner as in Example 1F or Example 2F, except that in the preparation of the negative electrode, CNT-2 was used instead of CNT-1 as the conductive material.

[0673] <Comparative Example 1F> A battery was produced in the same manner as in Example 1F, except that in preparing the electrolyte solution, the reference electrolyte solution was used as it was, and in producing the negative electrode, no conductive material was used, and the negative electrode was produced by the following method. [Preparation of negative electrode] A negative electrode was produced in the same manner as in Example 1F, except that no conductive material was used, and 96.7 parts by mass of the negative electrode active material, 1.3 parts by mass of sodium carboxymethyl cellulose as a thickener, and 2 parts by mass of styrene butadiene rubber as a binder were mixed in water to form a slurry.

[0674] <Comparative Examples 2F and 3F> A battery was produced in the same manner as in Example 1F or Example 2F, except that the same negative electrode as in Comparative Example 1F was used.

[0675] <Comparative example 4F, 5F> Batteries were produced in the same manner as in Example 1F or Example 2F, except that the reference electrolyte was used as it was in preparing the electrolyte.

[0676] Mode G <Compound> The compounds used in the present examples and comparative examples are shown below.

[0677] Compounds represented by general formula (G): Compounds 1G to 4G represented by the following formulae

[0678] [ka]

[0679] Carbon nanotubes CNT-1: diameter 1.3nm, SWCNT CNT-2: Diameter 8~15nm, MWCNT

[0680] Example 1G [Preparation of electrolyte] Under a dry argon atmosphere, thoroughly dried LiPF6 was dissolved in a mixture of ethylene carbonate, ethyl methyl carbonate, and diethyl carbonate (volume ratio 3:4:3) to give an electrolyte solution concentration of 1.2 mol / L. Vinylene carbonate was then added to the electrolyte solution to give a concentration of 0.5 mass%. This electrolyte solution was designated the "reference electrolyte solution." Compound 1G was added to this reference electrolyte solution to give a content of 2 mass % to prepare an electrolyte solution. Here, "content" refers to the content (mass %) when the entire electrolyte solution is taken as 100 mass %.

[0681] The preparation of the positive electrode, the preparation of the negative electrode, and the production of the battery were respectively similar to [Preparation of the positive electrode], [Preparation of the negative electrode], and [Production of the battery] in <Example 1A> of <<Aspect A>> above, to prepare a laminate-type nonaqueous electrolyte secondary battery.

[0682] <Examples 2G to 4G> Batteries were produced in the same manner as in Example 1G, except that in preparing the electrolyte solution, compounds 2G to 4G were used instead of compound 1G.

[0683] <Examples 5G to 8G> Batteries were produced in the same manner as in Examples 1G to 4G, except that in producing the negative electrode, CNT-2 was used instead of CNT-1 as the conductive material.

[0684] <Comparative Example 1G> A battery was produced in the same manner as in Example 1G, except that in preparing the electrolyte solution, the reference electrolyte solution was used as it was, and in producing the negative electrode, no conductive material was used, and the negative electrode was produced by the following method. [Preparation of negative electrode] A negative electrode was produced in the same manner as in Example 1G, except that no conductive material was used, and 96.7 parts by mass of the negative electrode active material, 1.3 parts by mass of sodium carboxymethyl cellulose as a thickener, and 2 parts by mass of styrene butadiene rubber as a binder were mixed in water to form a slurry.

[0685] <Comparative examples 2G~5G> Batteries were produced in the same manner as in Examples 1G to 4G, except that the same negative electrode as in Comparative Example 1G was used.

[0686] <Comparative examples 6G and 7G> In preparing the electrolyte solution, a battery was produced in the same manner as in Example 1G or Example 5G, except that the reference electrolyte solution was used as it was.

[0687] "Aspect H" <Compound> The compounds used in the present examples and comparative examples are shown below.

[0688] Compound (H): A compound represented by the following formula (Compound 1H):

[0689] [ka]

[0690] Carbon nanotubes CNT-1: diameter 1.3nm, SWCNT CNT-2: Diameter 8~15nm, MWCNT

[0691] Example 1H [Preparation of electrolyte] Under a dry argon atmosphere, thoroughly dried LiPF6 was dissolved in a mixture of ethylene carbonate, ethyl methyl carbonate, and diethyl carbonate (volume ratio 3:4:3) to give an electrolyte solution concentration of 1.2 mol / L. Vinylene carbonate was then added to the electrolyte solution to give a concentration of 0.5 mass%. This electrolyte solution was designated the "reference electrolyte solution." To this reference electrolyte solution, Compound 1H was added so as to have a content of 1 mass % to prepare an electrolyte solution. Here, the "content" refers to the content (mass %) when the entire electrolyte solution is taken as 100 mass %.

[0692] The preparation of the positive electrode, the preparation of the negative electrode, and the production of the battery were respectively similar to [Preparation of the positive electrode], [Preparation of the negative electrode], and [Production of the battery] in <Example 1A> of <<Aspect A>> above, to prepare a laminate-type nonaqueous electrolyte secondary battery.

[0693] <Example 2H> A battery was produced in the same manner as in Example 1H, except that in the preparation of the negative electrode, CNT-2 was used instead of CNT-1 as the conductive material.

[0694] <Comparative Example 1H> A battery was produced in the same manner as in Example 1H, except that in preparing the electrolyte solution, the reference electrolyte solution was used as it was, and in producing the negative electrode, no conductive material was used, and the negative electrode was produced by the following method. [Preparation of negative electrode] A negative electrode was produced in the same manner as in Example 1H, except that no conductive material was used, and 96.7 parts by mass of the negative electrode active material, 1.3 parts by mass of sodium carboxymethyl cellulose as a thickener, and 2 parts by mass of styrene butadiene rubber as a binder were mixed in water to form a slurry.

[0695] <Comparative example 2H> A battery was produced in the same manner as in Example 1H, except that the same negative electrode as in Comparative Example 1H was used.

[0696] <Comparative example 3H> A battery was produced in the same manner as in Example 1H, except that the reference electrolyte was used as it was in preparing the electrolyte.

[0697] <Comparative example 4H> A battery was produced in the same manner as in Example 2H, except that the reference electrolyte was used as it was in preparing the electrolyte.

[0698] Mode I <Compound> The compounds used in the present examples and comparative examples are shown below.

[0699] Compounds represented by general formula (I): Compounds 1I to 3I represented by the following formulae

[0700] [ka]

[0701] Carbon nanotubes CNT-1: diameter 1.3nm, SWCNT CNT-2: Diameter 8~15nm, MWCNT

[0702] Example 1I [Preparation of electrolyte] Under a dry argon atmosphere, thoroughly dried LiPF6 was dissolved in a mixture of ethylene carbonate, ethyl methyl carbonate, and diethyl carbonate (volume ratio 3:4:3) to give an electrolyte solution concentration of 1.2 mol / L. Vinylene carbonate was then added to the electrolyte solution to give a concentration of 0.5 mass%. This electrolyte solution was designated the "reference electrolyte solution." To this reference electrolyte solution, Compound 1I was added so as to have a content of 3 mass % to prepare an electrolyte solution. Here, the "content" refers to the content (mass %) when the entire electrolyte solution is taken as 100 mass %.

[0703] The preparation of the positive electrode, the preparation of the negative electrode, and the production of the battery were respectively similar to [Preparation of the positive electrode], [Preparation of the negative electrode], and [Production of the battery] in <Example 1A> of <<Aspect A>> above, to prepare a laminate-type nonaqueous electrolyte secondary battery.

[0704] Example 2I A battery was produced in the same manner as in Example 1I, except that in preparing the electrolyte solution, compound 2I was added in place of compound 1I so that the content would be 3 mass %.

[0705] Example 3I A battery was produced in the same manner as in Example 1I, except that in preparing the electrolyte solution, compound 3I was added in place of compound 1I so that the content would be 3 mass %.

[0706] Example 4I A battery was produced in the same manner as in Example 1I, except that in the preparation of the negative electrode, CNT-2 was used instead of CNT-1 as the conductive material.

[0707] Example 5I A battery was produced in the same manner as in Example 1I, except that the electrolyte solution was prepared by adding Compound 1I so that the content thereof became 30 mass %.

[0708] <Comparative Example 1I> A battery was produced in the same manner as in Example 1I, except that in preparing the electrolyte solution, the reference electrolyte solution was used as it was, and in producing the negative electrode, no conductive material was used, and the negative electrode was produced by the following method. [Preparation of negative electrode] A negative electrode was produced in the same manner as in Example 1I, except that no conductive material was used, and 96.7 parts by mass of the negative electrode active material, 1.3 parts by mass of sodium carboxymethyl cellulose as a thickener, and 2 parts by mass of styrene butadiene rubber as a binder were mixed in water to form a slurry.

[0709] <Comparative example 2I> A battery was produced in the same manner as in Example 1I, except that the same negative electrode as in Comparative Example 1I was used.

[0710] <Comparative example 3I> A battery was produced in the same manner as in Example 1I, except that the reference electrolyte was used as it was in preparing the electrolyte.

[0711] <Comparative Example 4I> A battery was produced in the same manner as in Example 2I, except that the reference electrolyte was used as it was in preparing the electrolyte.

[0712] <Evaluation of non-aqueous electrolyte secondary batteries> [Initial conditioning] Each battery obtained in the examples and comparative examples was charged to 3.72 V at 0.05 C (the current value at which the rated discharge capacity at a 1-hour rate is discharged in 1 hour is defined as 1 C; the same applies below) in a thermostatic chamber at 25°C, and then discharged to 2.5 V at 0.2 C. Next, the battery was charged to 4.1 V at 0.2 C, and then left to stand at 45°C for 72 hours for aging. Subsequently, the battery was discharged to 2.5 V at 0.2 C, and then charged to 4.2 V at 0.2 C, and then discharged to 2.5 V at 0.2 C. This cycle was repeated twice to perform initial conditioning.

[0713] [Charge / discharge cycle test] The non-aqueous electrolyte secondary batteries that had been initially conditioned by the above method were subjected to a charge-discharge cycle test under the following conditions. In a 45°C thermostatic chamber, the battery was discharged at 1C to 2.7V, then discharged again at 0.1C to 2.7V. It was then charged to 4.2V and discharged to 2.7V, a cycle of 206 times. The 1st, 52nd, 103rd, 104th, 155th, and 206th charges were performed at 0.2C, and the discharges at 0.05C, while the remaining charges and discharges were performed at 1C.

[0714] [Measurement of battery thickness change during cycling] The initially conditioned non-aqueous electrolyte secondary battery was charged to 3.75 V at 0.2 C, and then the thickness of the battery was measured using a micrometer. The above-mentioned cycle test was then performed for 206 cycles. After the test, the thickness of the battery was measured in the same way as after the initial conditioning, and the difference in thickness between the battery before and after the cycles was calculated. The difference in thickness between Aspects A to I and Comparative Examples 1A to 1I was normalized to 100 to be the reference, and the difference in thickness between the other Examples and Comparative Examples was calculated as "battery swelling." The results for Aspect A are shown in Table 1, the results for Aspect B in Table 2, the results for Aspect C in Table 3, the results for Aspect D in Table 4, the results for Aspect E in Table 5, the results for Aspect F in Table 6, the results for Aspect G in Table 7, the results for Aspect H in Table 8, and the results for Aspect I in Table 9. It can be said that the smaller the battery swelling value, the better the cycle characteristics.

[0715] [Table 1]

[0716] [Table 2]

[0717] [Table 3]

[0718] [Table 4]

[0719] [Table 5]

[0720] [Table 6]

[0721] [Table 7]

[0722] [Table 8]

[0723] [Table 9]

[0724] The results in Table 1 show that Examples 1A to 5A, which contain carbon nanotubes and a compound (A) represented by general formula (A), have improved battery swelling compared to Comparative Examples 4A and 5A, which do not contain a compound (A) represented by general formula (A). Comparative Examples 2A and 3A, which contain the compound (A) represented by the general formula (A) but do not contain carbon nanotubes, have improved properties compared to Comparative Example 1A, which does not contain the compound (A) represented by the general formula (A), but the improvement effect is smaller than that of Examples 1A to 5A. Comparing Example 1A with Example 3A, and Example 4A with Example 5A, it was found that Example 1A and Example 4A, which used CNT-1, a SWCNT with a small diameter, had better properties. Furthermore, the results of Example 2A showed that the effect of compound (A) could be suitably obtained even when the content was as very low as 0.01% by mass. From the above, it was confirmed that battery swelling can be effectively suppressed by combining a negative electrode containing a metal material and carbon nanotubes as active materials with an electrolyte containing compound (A) represented by general formula (A).

[0725] The results in Table 2 show that Examples 1B and 2B, which contain carbon nanotubes and a difluorophosphate anion-containing compound (B), have improved battery swelling compared to Comparative Examples 3B and 4B, which do not contain a difluorophosphate anion-containing compound (B). Comparative Example 2B, which contained a difluorophosphate anion-containing compound (B) but did not contain carbon nanotubes, showed improved properties compared to Comparative Example 1B, which did not contain a difluorophosphate anion-containing compound (B), but the improvement was smaller than that of Examples 1B and 2B. Comparing Example 1B and Example 2B, it was found that Example 1B, which used CNT-1, an SWCNT with a small diameter, had better properties. From the above, it was confirmed that battery swelling can be effectively suppressed by combining a negative electrode containing a metal material and carbon nanotubes as active materials with an electrolyte containing a difluorophosphate anion-containing compound (B).

[0726] The results in Table 3 show that Examples 1C and 2C, which contain carbon nanotubes and compound (C), have improved battery swelling compared to Comparative Examples 3C and 4C, which do not contain compound (C). Comparative Example 2C, which contains compound (C) but does not contain carbon nanotubes, has improved properties compared to Comparative Example 1C, which does not contain compound (C), but it was found that the improvement effect was smaller than that of Examples 1C and 2C. Comparing Example 1C and Example 2C, it was found that Example 1C, which used CNT-1, an SWCNT with a small diameter, had better properties. From the above, it was confirmed that battery swelling can be suitably suppressed by combining a negative electrode containing a metal material and carbon nanotubes as active materials with an electrolyte solution containing compound (C).

[0727] The results in Table 4 show that Examples 1D to 4D containing carbon nanotubes and an isocyanate compound (D) had improved battery swelling compared to Comparative Examples 4D and 5D containing no isocyanate compound (D). Comparative Examples 2D and 3D, which contain an isocyanate compound (D) but do not contain carbon nanotubes, have improved properties compared to Comparative Example 1D, which does not contain an isocyanate compound (D), but the improvement is smaller than that of Examples 1D to 4D. Comparing Examples 1D and 2D with Examples 3D and 4D, it was found that Examples 1D and 2D, which used CNT-1, an SWCNT with a small diameter, had better properties. From the above, it was confirmed that battery swelling can be suitably suppressed by combining a negative electrode containing a metal material and carbon nanotubes as active materials with an electrolyte solution containing an isocyanate compound (D).

[0728] The results in Table 5 show that Examples 1E and 2E, which contain carbon nanotubes and a compound represented by general formula (E), have improved battery swelling compared to Comparative Examples 3E and 4E, which do not contain a compound represented by general formula (E). It was found that Comparative Example 2E, which contains a compound represented by general formula (E) but does not contain carbon nanotubes, has improved properties compared to Comparative Example 1E, which does not contain a compound represented by general formula (E), but the improvement effect is smaller than that of Examples 1E or 2E. Comparing Example 1E and Example 2E, it was found that Example 1E, which used CNT-1, an SWCNT with a small diameter, had better properties. From the above, it was confirmed that battery swelling can be effectively suppressed by combining a negative electrode containing a metal material and carbon nanotubes as active materials with an electrolyte containing a compound represented by general formula (E).

[0729] The results in Table 6 show that Examples 1F to 4F, which contained carbon nanotubes and compound (F), had improved battery swelling compared to Comparative Examples 4F and 5F, which did not contain compound (F). Comparative Examples 2F and 3F, which contained compound (F) but did not contain carbon nanotubes, showed improved properties compared to Comparative Example 1F, which did not contain compound (F), but the improvement was smaller than in Examples 1F to 4F. Comparing Examples 1F and 2F with Examples 3F and 4F, it was found that Examples 1F and 2F, which used CNT-1, an SWCNT with a small diameter, had better properties. From the above, it was confirmed that battery swelling can be suitably suppressed by combining a negative electrode containing a metal material and carbon nanotubes as active materials with an electrolyte solution containing compound (F).

[0730] The results in Table 7 show that Examples 1G to 8G, which contained carbon nanotubes and compound (G), had improved battery swelling compared to Comparative Examples 6G and 7G, which did not contain compound (G). Comparative Examples 2G to 5G, which contain compound (G) but do not contain carbon nanotubes, have improved properties compared to Comparative Example 1G, which does not contain compound (G), but the improvement is smaller than that of Examples 1G to 4G and Examples 5G to 8G. Comparing Examples 1G to 4G with Examples 5G to 8G, it was found that Examples 1G to 4G, which used CNT-1, an SWCNT with a small diameter, had better characteristics. From the above, it was confirmed that battery swelling can be suitably suppressed by combining a negative electrode containing a metal material as an active material and carbon nanotubes with an electrolyte solution containing compound (G).

[0731] The results in Table 8 show that Examples 1H and 2H, which contained carbon nanotubes and compound (H), had improved battery swelling compared to Comparative Examples 3H and 4H, which did not contain compound (H). Comparative Example 2H, which contains compound (H) but does not contain carbon nanotubes, has improved properties compared to Comparative Example 1H, which does not contain compound (H), but it was found that the improvement was smaller than that of Examples 1H and 2H. Comparing Example 1H and Example 2H, it was found that Example 1H, which used CNT-1, an SWCNT with a small diameter, had better characteristics. From the above, it was confirmed that battery swelling can be suitably suppressed by combining a negative electrode containing a metal material and carbon nanotubes as active materials with an electrolyte solution containing compound (C).

[0732] The results in Table 9 show that Examples 1I to 5I, which contain carbon nanotubes and a compound represented by general formula (I), each have improved battery swelling compared to Comparative Examples 3I and 4I, which do not contain a compound represented by general formula (I). Comparative Example 2I, which contains a compound represented by general formula (I) but does not contain carbon nanotubes, has improved properties compared to Comparative Example 1I, which does not contain a compound represented by general formula (I), but it was found that the improvement effect was smaller than that of Examples 1I and 2I. Comparing Example 1I and Example 4I, it was found that Example 1I, which used CNT-1, an SWCNT with a small diameter, had better characteristics. From the above, it was confirmed that battery swelling can be effectively suppressed by combining a negative electrode containing a metal material and carbon nanotubes as active materials with an electrolyte containing a compound represented by general formula (I).

[0733] Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made thereto without departing from the spirit and scope of the present invention. This application is a Japanese patent application filed on February 16, 2024 (Patent Application No. 2024-021961), this application is a Japanese patent application filed on February 16, 2024 (Patent Application No. 2024-021962), this application is a Japanese patent application filed on February 16, 2024 (Patent Application No. 2024-021963), this application is a Japanese patent application filed on February 16, 2024 (Patent Application No. 2024-021964), this application is a Japanese patent application filed on February 16, 2024 (Patent Application No. 2024-021965), this application is a Japanese patent application filed on February 16, 2024 (Patent Application No. 2024-021966), this application is a Japanese patent application filed on February 16, 2024 (Patent Application No. 2024-021967), this application is a Japanese patent application filed on February 16, 2024 (Patent Application No. 2024-021968), this application is a Japanese patent application filed on February 16, 2024 (Patent Application No. 2024-021969), this application is a Japanese patent application filed on February 16, 2024 (Patent Application No. 2024-021970), this application is a Japanese patent application filed on February 16, 2024 (Patent Application No. 2024-021971), this application is a Japanese patent application filed on February 16, 2024 (P This application is based on a Japanese patent application filed on February 16, 2024 (Patent Application No. 2024-021965), a Japanese patent application filed on February 16, 2024 (Patent Application No. 2024-021966), a Japanese patent application filed on February 16, 2024 (Patent Application No. 2024-021967), and a Japanese patent application filed on February 16, 2024 (Patent Application No. 2024-021968), the contents of which are incorporated herein by reference. [Industrial Applicability]

[0734] The battery according to this embodiment can prevent battery swelling caused by repeated charge and discharge, and is useful as a laminated battery. The battery according to the present embodiment can be used in a variety of known applications, including, for example, notebook computers, pen-input personal computers, mobile personal computers, electronic book players, mobile phones, mobile fax machines, mobile copiers, mobile printers, headphone stereos, video movie players, LCD televisions, handheld vacuum cleaners, portable CD players, minidiscs, walkie-talkies, electronic organizers, calculators, memory cards, portable tape recorders, radios, backup power supplies, vehicles such as motors, motorcycles, mopeds, bicycles, and automobiles, lighting equipment, toys, game machines, clocks, power tools, flash devices, cameras, home backup power supplies, business backup power supplies, load-leveling power supplies, natural energy storage power supplies, and lithium-ion capacitors.

Claims

1. A battery comprising a positive electrode, a negative electrode, and an electrolyte, the negative electrode contains a metal material and carbon nanotubes as active materials, The diameter of the carbon nanotubes is 0.5 nm to 3.0 nm, the electrolytic solution contains an electrolyte, a non-aqueous solvent, and a specific compound; A battery comprising a difluorophosphate anion-containing compound (B) as the specific compound.

2. 2. The battery according to claim 1, wherein the metal material comprises at least one metal selected from the group consisting of Si, Sn, As, Sb, Al, Zn, and W, and at least one compound of the metal.

3. The metal material is Si, Si oxide, and SiC ｙ O ｚ At least one selected from the group consisting of SiC ｙ O ｚ The battery according to claim 1 or 2, wherein y satisfies 1≦y≦10 and 0≦z≦1.

4. 3. The battery according to claim 1, wherein the content of the metal material in the active material in the negative electrode is 0.1% by mass to 50% by mass.

5. 3. The battery of claim 1, wherein the negative electrode further comprises graphite.

6. The battery of claim 1 or 2, wherein the carbon nanotubes comprise single-walled carbon nanotubes.

7. The battery according to claim 1 or 2, wherein the positive electrode contains a compound represented by the following composition formula (β): Li ａ Ni ｂ Co ｃ M ｄ O ２ (β) (In composition formula (β), 0.9≦a≦1.1, 0.5≦b≦0.98, 0.01≦c≦0.2, 0.01≦d≦0.5, and b+c+d=1. M is a metal element containing at least one element selected from the group consisting of Mn, Al, Mg, Zr, Fe, Ti, and Er, and excluding Li, Ni, and Co.)

8. 3. The battery according to claim 1, wherein the following relational expression (1) is satisfied when the total content of the specific compounds in the electrolyte is C mass % and the diameter of the carbon nanotubes is R nm: 0.0033≦C / R≦2 (1)

9. The battery according to claim 1 or 2, wherein the following relational expression (2) is satisfied when the total content of the specific compounds in the electrolyte is C mass % and the average particle size of the metal material is D μm: 0.001≦C / D≦200 (2)

10. The battery according to claim 1 or 2, wherein the average particle size of the metal material is larger than the diameter of the carbon nanotubes.

11. A method for manufacturing a battery, comprising the steps of housing a positive electrode and a negative electrode in a container and injecting an electrolyte into the container, the negative electrode contains a metal material as an active material and carbon nanotubes, The diameter of the carbon nanotubes is 0.5 nm to 3.0 nm, the electrolytic solution contains an electrolyte, a non-aqueous solvent, and a specific compound; The method for producing a battery includes a difluorophosphate anion-containing compound (B) as the specific compound.

12. A vehicle comprising the battery according to claim 1 or 2.

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