Composition, method for producing composition, battery, method for producing battery, and vehicle

Abstract

A new composition that can exert a favorable effect when added to a battery electrolyte is provided. [Solution] A composition comprising a compound (A) containing at least one of a compound (A1) represented by the following general formula (1) and a compound (A2) represented by the following general formula (2), and a siloxane compound (B) having 8 or more silicon atoms: [Formula 1] TIFF2026037061000043.tif46161

Description

[Technical Field]

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

[0002] Batteries, such as lithium-ion secondary batteries, are being used in a wide range of applications, including as power sources for small devices such as mobile phones and laptops, and for vehicles such as electric vehicles. Therefore, numerous studies have been conducted on various battery components, including positive electrodes, negative electrodes, and electrolytes, in order to improve battery performance.

[0003] In the case of electrolytes, numerous studies have been conducted on the components of electrolytes, such as additives, electrolytes, and solvents, with the aim of improving battery characteristics. For example, Patent Document 1 discloses a non-aqueous electrolyte containing a fluorine-based nonionic surfactant consisting of silicone oil and fluoropolyoxyethylene ether. Furthermore, Patent Document 2 discloses a non-aqueous electrolyte containing a specific silane compound. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-173651 [Patent Document 2] International Publication No. 2019 / 059365 Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, there has been an increasing demand for higher performance batteries, and there is a need to achieve a higher level of battery capacity. One method for increasing the capacity of a battery is to pack as much electrode active material as possible into a limited battery volume. Specifically, there are methods such as increasing the density of the active material layer of the electrode and reducing the volume occupied by materials other than the active material inside the battery.

[0006] However, reducing the void space inside a battery to increase capacity can significantly increase the internal pressure of the battery if even a small amount of gas is generated by decomposition of the electrolyte. In particular, if the battery is left without charging after discharge, the battery voltage will continue to decrease, leading to a state known as overdischarge, where the battery voltage falls below the minimum voltage limit expected for use. In this overdischarge state, gas generation due to reductive decomposition of the electrolyte on the electrode surface increases, raising concerns about battery swelling and deterioration.

[0007] In contrast, it was found that when the nonaqueous electrolyte solution disclosed in Patent Document 1 was used, a good protective film was not formed on the positive electrode surface, and gas generation in an overdischarge state could not be suppressed. Also, when the nonaqueous electrolyte solution disclosed in Patent Document 2 was used, uneven wetting of the electrolyte onto the positive electrode active material and the negative electrode active material occurred, and a protective film was not formed uniformly on the positive electrode surface and the negative electrode surface, and the effect of suppressing gas generation in an overdischarge state was found to be limited.

[0008] The present invention has been made in view of the above problems, and aims to provide a new composition that can exhibit good effects when added to a battery electrolyte. One aspect of the effects is the effect of suppressing gas generation in an overdischarge state. That is, one object of the present invention is to provide a composition that, when added to a battery electrolyte, exhibits excellent effects of suppressing gas generation in an overdischarge state. Another object of the present invention is to provide a composition used as an electrolyte solution that can exhibit good effects when used in a battery, and in one aspect, to provide a composition used as an electrolyte solution that has an excellent effect of suppressing gas generation in an overdischarge state. Another object of the present invention is to provide a method for producing the above-mentioned new composition used as an electrolyte, a battery that is excellent in the effect of suppressing gas generation in an over-discharge state and a method for producing the same, and a vehicle that includes the above-mentioned battery. [Means for solving the problem]

[0009] As a result of extensive research to solve the above problems, the present inventors have found that a combination of a compound (A) described below and a siloxane compound (B) described below can exert favorable effects, such as the effect of suppressing gas generation in an overdischarge state, when used in a battery electrolyte, and have thus completed the present invention.

[0010] That is, the gist of the present invention is as follows. [1] A composition comprising a compound (A) containing at least one of a compound (A1) represented by the following general formula (1) and a compound (A2) represented by the following general formula (2), and a siloxane compound (B) having 8 or more silicon atoms:

[0011] [ka]

[0012] (In general formula (1), R 101 and R 102 are each independently a hydrogen atom, a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, or -SiR 103 R 104 R 105 is a silyl group represented by R 103 ~R 105 are each independently a hydrogen atom, a halogen atom, a hydrocarbon group of 1 to 12 carbon atoms which may have a substituent, or an alkoxy group of 1 to 12 carbon atoms which may have a substituent, and Y is a hydrogen atom, a halogen atom, a hydrocarbon group of 1 to 12 carbon atoms which may have a substituent, an alkoxy group of 1 to 12 carbon atoms which may have a substituent, -NR 106 -SiR 107 R 108 R 109 or a group represented by -NR110 -R 111 is a group represented by R 106 , R 110 and R 111 are each independently a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, and R 107 ~R 109 are each independently a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, or an alkoxy group having 1 to 12 carbon atoms which may have a substituent. 101 or R 102 may be bonded to form a ring.)

[0013] [ka]

[0014] (In general formula (2), R 201 ~R 203 are each independently a hydrogen atom, an optionally substituted alkyl group having 1 to 10 carbon atoms, an optionally substituted aryl group having 6 to 18 carbon atoms, or an optionally substituted aralkyl group having 7 to 18 carbon atoms, and Z is an optionally substituted alkenyl group or alkynyl group having 2 to 10 carbon atoms.

[0015] [2] The compound (A) is R in the general formula (1). 101 and R 102 At least one of the groups is -SiR 103 R 104 R 105 The composition according to [1], comprising a compound having a silyl group represented by the formula: [3] The composition according to [1] or [2], wherein the compound (A2) is a compound in which Z in the general formula (2) is at least one selected from the group consisting of a vinyl group, an allyl group, and a methallyl group. [4] The composition according to any one of [1] to [3], wherein the siloxane compound (B) comprises at least one of a siloxane compound (B1) represented by the following general formula (3) and a siloxane compound (B2) represented by the following general formula (4):

[0016] [ka]

[0017] (In general formula (3), R 301 is an alkyl group having 1 to 3 carbon atoms or a phenyl group, and R 302 is an alkyl group having 1 to 3 carbon atoms, a phenyl group, a polyether group, a carboxylate group, a sulfonate group, a phosphite group, or a phosphate group, and R 303 ~R 308 are each independently an alkyl group having 1 to 3 carbon atoms or a phenyl group, n3 is an integer of 6 or more and 100,000 or less, and n3 R 301 and R 302 may be the same or different.)

[0018] [ka]

[0019] (In general formula (4), R 401 is an alkyl group having 1 to 3 carbon atoms or a phenyl group, and R 402 is an alkyl group having 1 to 3 carbon atoms, a phenyl group, a polyether group, a carboxylate group, a sulfonate group, a phosphite group, or a phosphate group, n4 is an integer of 8 or more and 100,000 or less, and n4 R 401 and R 402 may be the same or different.)

[0020] [5] The composition according to any one of [1] to [4], further comprising an electrolyte and a non-aqueous solvent, and used as an electrolytic solution. [6] The composition according to [5], wherein the total content of the compound (A) in the composition is 0.0001% by mass or more and 0.2% by mass or less. [7] The composition according to [5] or [6], wherein the total content of the siloxane compound (B) in the composition is 0.0001% by mass or more and 0.2% by mass or less.

[0021] [8] A method for producing the composition according to any one of [5] to [7], A method for producing a composition, comprising the step of dissolving the compound (A), the siloxane compound (B), and the electrolyte in the non-aqueous solvent. [9] A battery comprising a positive electrode, a negative electrode, and the composition according to any one of [5] to [7].

[10] A method for producing a battery, comprising the steps of housing a positive electrode and a negative electrode in an exterior body, and injecting the composition according to any one of [5] to [7] into the exterior body.

[11] A vehicle including the battery described in [9]. [Effects of the Invention]

[0022] The composition according to the present embodiment can exhibit favorable effects when added to an electrolyte solution of a battery. One aspect of the composition according to the present embodiment is excellent in the effect of suppressing gas generation in an overdischarge state when added to an electrolyte solution of a battery. Furthermore, the composition according to the present embodiment aims to provide a composition to be used as an electrolyte solution that can exhibit favorable effects when used in a battery, and in one aspect, a composition to be used as an electrolyte solution that has an excellent effect of suppressing gas generation in an overdischarge state is provided. Furthermore, the method for producing a composition according to this embodiment exhibits favorable effects such as the effect of suppressing gas generation in an overdischarge state when the resulting composition is used as an electrolyte in a battery. Furthermore, the battery according to this embodiment or the battery obtained by the manufacturing method thereof is excellent in suppressing gas generation in an overdischarge state.Furthermore, the vehicle according to this embodiment is excellent in suppressing gas generation in an overdischarge state of the battery included therein. DETAILED DESCRIPTION OF THE INVENTION

[0023] The following describes in detail the embodiments of the present invention, but the following description is merely an example of an embodiment of the present invention and the present invention is not limited to these details. 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.

[0024] [1. Composition] The composition according to the present embodiment contains a compound (A) containing at least one of a compound (A1) represented by the following general formula (1) and a compound (A2) represented by the following general formula (2), and a siloxane compound (B) having 8 or more silicon atoms:

[0025] [ka]

[0026] (In general formula (1), R 101 and R 102 are each independently a hydrogen atom, a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, or -SiR 103 R 104 R 105 is a silyl group represented by R 103 ~R 105 are each independently a hydrogen atom, a halogen atom, a hydrocarbon group of 1 to 12 carbon atoms which may have a substituent, or an alkoxy group of 1 to 12 carbon atoms which may have a substituent, and Y is a hydrogen atom, a halogen atom, a hydrocarbon group of 1 to 12 carbon atoms which may have a substituent, an alkoxy group of 1 to 12 carbon atoms which may have a substituent, -NR 106 -SiR 107 R 108 R 109 or a group represented by -NR 110 -R 111 is a group represented by R 106 , R 110 and R 111 are each independently a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, and R107 ~R 109 are each independently a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, or an alkoxy group having 1 to 12 carbon atoms which may have a substituent. 101 or R 102 may be bonded to form a ring.)

[0027] [ka]

[0028] (In general formula (2), R 201 ~R 203 are each independently a hydrogen atom, an optionally substituted alkyl group having 1 to 10 carbon atoms, an optionally substituted aryl group having 6 to 18 carbon atoms, or an optionally substituted aralkyl group having 7 to 18 carbon atoms, and Z is an optionally substituted alkenyl group or alkynyl group having 2 to 10 carbon atoms.

[0029] The composition according to the present embodiment can exhibit favorable effects when added to a battery electrolyte or when used as an electrolyte itself by further containing an electrolyte, etc. One of the effects is, for example, the effect of suppressing gas generation in an overdischarge state. The inventors believe that the reason for this excellent effect is as follows. However, the present invention is not limited to the content described below.

[0030] Conventionally, siloxane compounds are known as components that can reduce foaming of an electrolyte solution when added to the electrolyte solution. In contrast, the composition according to the present embodiment focuses on the fact that the inclusion of a specific siloxane compound (B) can reduce the surface tension of the electrolyte solution and improve the wettability of the electrolyte solution to the surfaces of the positive electrode active material and the negative electrode active material. It is believed that the improved wettability increases the surface area of ​​the positive electrode active material and the negative electrode active material that come into contact with the electrolyte solution, thereby reducing the internal resistance of the battery. On the other hand, an increase in the contact area between the electrolyte and the active material also increases the number of sites where the electrolyte decomposition reaction occurs, which may result in a shortened battery life and an increase in reductive decomposition gases at the positive electrode during overdischarge.

[0031] In contrast, it has been discovered that the composition according to this embodiment further contains a specific compound (A), which provides an effect of suppressing gas generation in an overdischarge state. This is thought to be because the presence of specific compound (A) allows the formation of a uniform protective coating over the entire surface of the high-potential positive electrode in a charged state, where the electrolyte solution is uniformly spread by the siloxane compound (B). Specifically, when compound (A1) represented by general formula (1) is used as compound (A), it is thought that due to the N-C=O structure in compound (A1), oxidative decomposition occurs at a potential of about 4.5 V or higher, forming an effective protective coating. Furthermore, when compound (A2) represented by general formula (2) is used, it is thought that due to the Si-Z structure in compound (A2), oxidative decomposition occurs at a potential of about 4 V, forming an effective protective coating. These protective coatings (hereinafter sometimes referred to as "positive electrode protective coatings") are stable protective coatings formed by electrochemical decomposition of compound (A). Therefore, even if the positive electrode potential drops during overdischarge, the coating structure does not undergo reductive decomposition, and the protective effect can be maintained. Furthermore, the uniform formation of the protective coating ensures that the protective effect is obtained evenly over the entire positive electrode surface. From the above, it is considered that the composition according to this embodiment, which uses the compound (A) in combination with the siloxane compound (B), has an excellent effect of suppressing gas generation in an overdischarge state when used as an electrolyte for a battery.

[0032] [1-1. Compound (A)] The compound (A) in this embodiment includes at least one of a compound (A1) represented by the following general formula (1) and a compound (A2) represented by the following general formula (2). When the composition according to this embodiment is used as an additive to an electrolyte solution or as the electrolyte solution itself, compound (A) preferably contains compound (A1) from the viewpoint of effectively forming a positive electrode protective coating when the battery is operated at a charge voltage of 4.5 V or higher. On the other hand, when the battery is operated at a charge voltage of less than 4.5 V, compound (A) preferably contains compound (A2) from the viewpoint of effectively forming a positive electrode protective coating.

[0033] When the battery is used for multiple purposes, it is preferable that the compound (A) contains the compound (A1) and the compound (A2), from the viewpoint of effectively forming a positive electrode protective coating while adapting to various charging voltages. When compound (A1) and compound (A2) are used in combination as compound (A), the mass ratio of the content (mass%) of compound (A2) to the content (mass%) of compound (A1) in the composition according to this embodiment (content (mass%) of compound (A2) / content (mass%) of compound (A1)) is preferably 0.01 to 100. From the viewpoint of effectively forming a positive electrode protective coating, this mass ratio is preferably 0.01 or more, more preferably 0.05 or more, and is preferably 100 or less, more preferably 20 or less. When compound (A1) or compound (A2) contains two or more compounds, the above-mentioned respective contents refer to the total content thereof.

[0034] [1-1-1. Compound (A1)] The compound (A1) in this embodiment is represented by the following general formula (1): The compound (A1) may be used alone or in any combination and ratio of two or more kinds.

[0035] [ka]

[0036] (In general formula (1), R 101 and R 102 are each independently a hydrogen atom, a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, or -SiR103 R 104 R 105 is a silyl group represented by R 103 ~R 105 are each independently a hydrogen atom, a halogen atom, a hydrocarbon group of 1 to 12 carbon atoms which may have a substituent, or an alkoxy group of 1 to 12 carbon atoms which may have a substituent, and Y is a hydrogen atom, a halogen atom, a hydrocarbon group of 1 to 12 carbon atoms which may have a substituent, an alkoxy group of 1 to 12 carbon atoms which may have a substituent, -NR 106 -SiR 107 R 108 R 109 or a group represented by -NR 110 -R 111 is a group represented by R 106 , R 110 and R 111 are each independently a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, and R 107 ~R 109 are each independently a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, or an alkoxy group having 1 to 12 carbon atoms which may have a substituent. 101 or R 102 may be bonded to form a ring.)

[0037] R in general formula (1) 101 and R 102 are each independently a hydrogen atom, a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, or -SiR 103 R 104 R 105 Among these, from the viewpoint of enhancing the protective effect on the electrode surface, a silyl group represented by each independently a hydrogen atom, a hydrocarbon group having 1 to 6 carbon atoms which may have a substituent, or -SiR 103 R 104 R 105 is preferably a hydrogen atom or a silyl group represented by -SiR 103 R 104 R 105 A silyl group represented by the following formula is more preferred. R 101 and R102 In order to enhance the protective effect on the electrode surface, at least one of them is -SiR 103 R 104 R 105 More preferably, the composition according to this embodiment includes, as the compound (A1), a silyl group represented by R 101 and R 102 At least one of the groups is -SiR 103 R 104 R 105 It is more preferable that the compound contains a silyl group represented by the following formula:

[0038] R 101 and R 102 When each of the groups is a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, the number of carbon atoms in the hydrocarbon group is independently 1 to 12, and from the viewpoint of enhancing the protective effect on the electrode surface, each of the groups is independently preferably 1 to 6, and more preferably 1 to 4.

[0039] R 101 and R 102 Examples of the hydrocarbon groups of R are independently alkyl groups, alkenyl groups, alkynyl groups, aryl groups, and aralkyl groups. 101 and R 102 The hydrocarbon groups may be used alone or in any combination of two or more kinds in any ratio. R 101 and R 102 The hydrocarbon groups are each independently preferably an alkyl group, an alkenyl group, an alkynyl group, an aryl group, or an aralkyl group, and from the viewpoint of enhancing the protective effect on the electrode surface, are each independently more preferably an alkyl group or an alkenyl group, and even more preferably an alkyl group.

[0040] R 101 and R 102Examples of the alkyl group of the hydrocarbon group include chain alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, n-pentyl, hexyl, heptyl, octyl, nonyl, and decyl; and cyclic alkyl groups such as cyclobutyl, cyclopentyl, cyclohexyl, and cycloheptyl. 101 and R 102 The alkyl group of the hydrocarbon group may be used alone or in any combination and ratio of two or more kinds. R 101 and R 102 From the viewpoint of localizing compound (A1) near the surfaces of the positive electrode active material and the negative electrode active material and facilitating the uniform formation of a good protective coating, the alkyl groups of the hydrocarbon group are each independently preferably a methyl group, an ethyl group, an n-propyl group, an n-butyl group, a tert-butyl group, an n-pentyl group, a hexyl group, or a cyclohexyl group, more preferably a methyl group, an ethyl group, an n-propyl group, an n-butyl group, a tert-butyl group, an n-pentyl group, or a cyclohexyl group, and even more preferably a methyl group, an ethyl group, an n-butyl group, a tert-butyl group, or a cyclohexyl group.

[0041] R 101 and R 102 Examples of the alkenyl group of the hydrocarbon 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. 101 and R 102 The alkenyl group of the hydrocarbon group may be used alone or in any combination of two or more kinds in any ratio. R 101 and R 102 From the viewpoint of localizing compound (A1) near the surfaces of the positive electrode active material and the negative electrode active material, the alkenyl groups of the hydrocarbon groups are each independently preferably a vinyl group, an allyl group, a methallyl group, or a 2-butenyl group, more preferably a vinyl group, an allyl group, or a methallyl group, and even more preferably a vinyl group or an allyl group.

[0042] R 101 and R102 Examples of the alkynyl group in the hydrocarbon group R are each independently an ethynyl group, a 2-propynyl group, a 2-butynyl group, a 3-butynyl group, a 4-pentynyl group, a 5-hexynyl group, etc. 101 and R 102 The alkynyl group of the hydrocarbon group may be used alone or in any combination of two or more kinds in any ratio. R 101 and R 102 From the viewpoint of localizing compound (A1) near the surfaces of the positive electrode active material and the negative electrode active material, the alkynyl groups of the hydrocarbon group are each independently preferably an ethynyl group, a 2-propynyl group, a 2-butynyl group, or a 3-butynyl group, more preferably a 2-propynyl group or a 3-butynyl group, and even more preferably a 2-propynyl group.

[0043] R 101 and R 102 The aryl groups in the hydrocarbon groups of R are each independently exemplified by a phenyl group, a tolyl group, etc. 101 and R 102 The aryl group of the hydrocarbon group may be used alone or in any combination of two or more kinds in any ratio. R 101 and R 102 The aryl group of the hydrocarbon group is preferably a phenyl group, from the viewpoint of localizing the compound (A1) near the surfaces of the positive electrode active material and the negative electrode active material.

[0044] R 101 and R 102 Examples of the aralkyl group of the hydrocarbon group R are each independently a benzyl group, a phenethyl group, etc. 101 and R 102 The aralkyl group of the hydrocarbon group may be used alone or in any combination of two or more kinds in any ratio. R 101 and R 102 The aralkyl group of the hydrocarbon group is preferably a benzyl group, from the viewpoint of localizing the compound (A1) near the surfaces of the positive electrode active material and the negative electrode active material.

[0045] R 101 and R 102 When is a hydrocarbon group, examples of the substituent that may be substituted include a cyano group, an isocyanato group, an oxo group, an acyloxy group, a fluorine atom, and a trifluoromethyl group.

[0046] R 101 and R 102 Ga-SiR 103 R 104 R 105 In the case where the silyl group is a silyl group represented by 103 ~R 105 are each independently a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, or an alkoxy group having 1 to 12 carbon atoms which may have a substituent. Among these, from the viewpoint of enhancing the protective effect on the electrode surface, R 103 ~R 105 are each independently preferably a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent or an alkoxy group having 1 to 12 carbon atoms which may have a substituent, and more preferably a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent.

[0047] R 103 ~R 105 From the viewpoint of enhancing the protective effect on the electrode surface, at least one of R is preferably a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, more preferably an alkyl group having 1 to 12 carbon atoms which may have a substituent, and R 103 ~R 105 It is more preferable that all of the above groups are alkyl groups having 1 to 12 carbon atoms which may have a substituent.Moreover, it is more preferable that the above hydrocarbon groups and alkyl groups do not have a substituent.

[0048] Also, R 103 ~R 105 may be the same or different, but from the viewpoint of ease of synthesis of compound (A1), R 103 ~R 105 Preferably, at least two of R 103 ~R 105It is more preferred that all of the following are the same:

[0049] When the optionally substituted hydrocarbon group having 1 to 12 carbon atoms or the optionally substituted alkoxy group having 1 to 12 carbon atoms 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 or alkoxy group, which is 1 to 12. In other words, the number of carbon atoms constituting the main chain of the hydrocarbon group or alkoxy group may be 1 to 12.

[0050] R 103 ~R 105 When each of the halogen atoms is independently a fluorine atom, a chlorine atom, or a bromine atom, the halogen atom is preferably a fluorine atom from the viewpoint of reducing electrochemical side reactions.

[0051] R 103 ~R 105 When each of the groups is a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, the number of carbon atoms in the hydrocarbon group is independently 1 to 12, and from the viewpoint of enhancing the protective effect on the electrode surface, each of the groups is independently preferably 1 to 6, and more preferably 1 to 4.

[0052] R 103 ~R 105 Examples of the hydrocarbon groups of R are independently alkyl groups, alkenyl groups, alkynyl groups, aryl groups, and aralkyl groups. 103 ~R 105 The hydrocarbon groups may be used alone or in any combination of two or more kinds in any ratio. R 103 ~R 105 The hydrocarbon groups are each independently preferably an alkyl group, an alkenyl group, an alkynyl group, an aryl group, or an aralkyl group, and from the viewpoint of enhancing the protective effect on the electrode surface, an alkyl group or an alkenyl group is more preferable, and an alkyl group is even more preferable.

[0053] R 103 ~R 105Examples of the alkyl group of the hydrocarbon group include chain alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, n-pentyl, hexyl, heptyl, octyl, nonyl, and decyl; and cyclic alkyl groups such as cyclobutyl, cyclopentyl, cyclohexyl, and cycloheptyl. 103 ~R 105 The alkyl group of the hydrocarbon group may be used alone or in any combination and ratio of two or more kinds. R 103 ~R 105 From the viewpoint of localizing compound (A1) near the surfaces of the positive electrode active material and the negative electrode active material, the alkyl groups of the hydrocarbon group are each independently preferably a methyl group, an ethyl group, an n-propyl group, an n-butyl group, a tert-butyl group, an n-pentyl group, a hexyl group, or a cyclohexyl group, more preferably a methyl group, an ethyl group, an n-propyl group, an n-butyl group, a tert-butyl group, an n-pentyl group, or a cyclohexyl group, still more preferably a methyl group, an ethyl group, a tert-butyl group, or an isopropyl group, and particularly preferably a methyl group.

[0054] R 103 ~R 105 Examples of the alkenyl group of the hydrocarbon 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. 103 ~R 105 The alkenyl group of the hydrocarbon group may be used alone or in any combination of two or more kinds in any ratio. R 103 ~R 105 From the viewpoint of localizing compound (A1) near the surfaces of the positive electrode active material and the negative electrode active material, the alkenyl groups of the hydrocarbon groups are each independently preferably a vinyl group, an allyl group, a methallyl group, or a 2-butenyl group, more preferably a vinyl group, an allyl group, or a methallyl group, and even more preferably a vinyl group or an allyl group.

[0055] R 103 ~R 105Examples of the alkynyl group in the hydrocarbon group R are each independently an ethynyl group, a 2-propynyl group, a 2-butynyl group, a 3-butynyl group, a 4-pentynyl group, a 5-hexynyl group, etc. 103 ~R 105 The alkynyl group of the hydrocarbon group may be used alone or in any combination of two or more kinds in any ratio. R 103 ~R 105 From the viewpoint of localizing compound (A1) near the surfaces of the positive electrode active material and the negative electrode active material, the alkynyl groups of the hydrocarbon group are each independently preferably an ethynyl group, a 2-propynyl group, a 2-butynyl group, or a 3-butynyl group, more preferably a 2-propynyl group or a 3-butynyl group, and even more preferably a 2-propynyl group.

[0056] R 103 ~R 105 The aryl groups in the hydrocarbon groups of R are each independently exemplified by a phenyl group, a tolyl group, etc. 103 ~R 105 The aryl group of the hydrocarbon group may be used alone or in any combination of two or more kinds in any ratio. R 103 ~R 105 The aryl group of the hydrocarbon group is preferably a phenyl group, from the viewpoint of localizing the compound (A1) near the surfaces of the positive electrode active material and the negative electrode active material.

[0057] R 103 ~R 105 Examples of the aralkyl group of the hydrocarbon group R are each independently a benzyl group, a phenethyl group, etc. 103 ~R 105 The aralkyl group of the hydrocarbon group may be used alone or in any combination of two or more kinds in any ratio. R 103 ~R 105 The aralkyl group of the hydrocarbon group is preferably a benzyl group, from the viewpoint of localizing the compound (A1) near the surfaces of the positive electrode active material and the negative electrode active material.

[0058] R103 ~R 105 When each of the alkoxy groups is an alkoxy group having 1 to 12 carbon atoms which may have a substituent, the number of carbon atoms in the alkoxy group is independently 1 to 12, preferably 1 to 6, and more preferably 1 to 4, from the viewpoint of enhancing the protective effect on the electrode surface.

[0059] R 103 ~R 105 Examples of the alkoxy groups in R are, independently, methoxy, ethoxy, propoxy, isopropoxy, and butoxy. 103 ~R 105 The alkoxy groups may be used alone or in any combination of two or more kinds in any ratio. R 103 ~R 105 The alkoxy groups are preferably each independently a methoxy group or an ethoxy group, from the viewpoint of localizing the compound (A1) near the surfaces of the positive electrode active material and the negative electrode active material.

[0060] R 103 ~R 105 When is a hydrocarbon group or an alkoxy group, examples of the substituent that may be present include a cyano group, an isocyanato group, an oxo group (=O), an acyl group (-(C=O)-R a ), acyloxy group (-O(C=O)-R a ), alkoxycarbonyl group (-(C=O)OR a ), sulfonyl group (-SO2-R a ), sulfonyloxy group (-O(SO2)-R a ), alkoxysulfonyl group (-(SO2)-OR a ), alkoxysulfonyloxy group (-O-(SO2)-OR a ), alkoxycarbonyloxy group (-O-(C=O)-OR a ), alkoxy group (-OR a ), an acrylic group, a methacrylic group, a halogen atom (preferably a fluorine atom), a trifluoromethyl group, etc. 103 ~R 105The substituents of the hydrocarbon group and alkoxy group may be used alone or in any combination and ratio of two or more kinds.

[0061] In addition, R a R is an alkyl group having 1 to 10 carbon atoms, an alkylene 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. a When is an alkylene group, R a is R 103 ~R 105 may be bonded to any one of the following to form a ring. Here, the alkyl group and alkylene group each have 1 to 10 carbon atoms, preferably 1 to 6, and more preferably 1 to 4. The alkenyl group and alkynyl group each have 2 to 10 carbon atoms, more preferably 2 to 6.

[0062] R a When R is an alkyl group having 1 to 10 carbon atoms, 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. a The alkyl group may be used alone or in any combination of two or more kinds in any ratio. R a From the viewpoint of enhancing the protective effect on the electrode surface, the alkyl group is preferably a methyl group, an ethyl group, an n-propyl group, an n-butyl group, a tert-butyl group, an n-pentyl group, or a hexyl group, more preferably a methyl group, an ethyl group, an n-propyl group, an n-butyl group, a tert-butyl group, or an n-pentyl group, and even more preferably a methyl group or an ethyl group.

[0063] R a When R is an alkylene group having 1 to 10 carbon atoms, examples of the alkylene group include a methylene group, an ethylene group, a trimethylene group, a propylidene group, an isopropylidene group, a tetramethylene group, a pentamethylene group, a hexamethylene group, and a cyclohexylene group. aThe alkylene groups may be used alone or in any combination of two or more kinds in any ratio. R a From the viewpoint of enhancing the protective effect on the electrode surface, the alkylene group is preferably a methylene group, an ethylene group, a trimethylene group, a propylidene group, an isopropylidene group, a tetramethylene group, a pentamethylene group, or a hexamethylene group, more preferably a methylene group, an ethylene group, or a trimethylene group, and even more preferably a methylene group or an ethylene group.

[0064] R a When R is an alkenyl group having 2 to 10 carbon atoms, 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. a The alkenyl groups may be used alone or in any combination of two or more kinds in any ratio. R a From the viewpoint of enhancing the protective effect on the electrode surface, the alkenyl group is preferably a vinyl group, allyl group, methallyl group or 2-butenyl group, more preferably a vinyl group, allyl group or methallyl group, and even more preferably an allyl group or methallyl group.

[0065] R a When R is an alkynyl group having 2 to 10 carbon atoms, 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. a The alkynyl groups may be used alone or in any combination of two or more kinds in any ratio. R a From the viewpoint of enhancing the protective effect on the electrode surface, the alkynyl group is preferably an ethynyl group, a 2-propynyl group, a 2-butynyl group, or a 3-butynyl group, more preferably an ethynyl group, a 2-propynyl group, or a 3-butynyl group, and even more preferably an ethynyl group or a 2-propynyl group.

[0066] R 103 ~R 105When represents an alkyl group or an alkoxy group having 1 to 10 carbon atoms, the substituents of the alkyl group and the alkoxy group are each independently preferably a cyano group, an isocyanato group, an oxo group, an acyloxy group, a fluorine atom, or a trifluoromethyl group, more preferably an oxo group, an isocyanato group, an acyloxy group, a fluorine atom, or a trifluoromethyl group, and even more preferably an oxo group, an acyloxy group, a fluorine atom, or a trifluoromethyl group, from the viewpoint of enhancing the protective effect on the electrode surface.

[0067] -SiR 103 R 104 R 105 Examples of the silyl group represented by the formula (I) include -Si(CH3)3, -Si(CH3)2(C2H5), -Si(CH3)2(CH=CH2), -Si(CH3)2(CH2CH2CH3), -Si(CH3)2(CH2CH=CH2), -Si(CH3)2[CH(CH3)2], -Si(CH3)2[(CH2)3CH3)], -Si(CH3)2[CH2CH(CH3)2], -Si(CH3)2[C (CH3)3], -Si(CH3)2(C6H5), -Si(CH3)(C6H5)2, -Si(C6H5)3, -Si(C2H5)3, -Si(CH=CH2)3, -Si(CH2CH2CH3)3 , -Si[CH(CH3)2]3, -Si(CH2CH=CH2)3, -Si(CH3)(C6H5)(CH=CH2), -Si(C6H5)2(CH=CH2), -Si(CF3)3, and the like. -SiR 103 R 104 R 105 The silyl group represented by the formula (I) may be used alone or in any combination and ratio of two or more kinds. -SiR 103 R 104 R 105From the viewpoint of enhancing the protective effect on the electrode surface, the silyl group represented by the formula (I) is preferably -Si(CH3)3, -Si(CH3)2(CH=CH2), -Si(CH3)2(CH2CH=CH2), -Si(CH3)2[C(CH3)3], -Si(C2H5)3, -Si[CH(CH3)2]3, -Si(CH3)(CH6H5)(CH=CH2) or -Si(CH6H5)2(CH=CH2), and more preferably -Si(CH3)2(CH=CH2), -Si(CH3)2[C(CH3)3], -Si[CH(CH3)2]3 or -Si(CH3)2(CH2CH=CH2).

[0068] In the general formula (1), Y is a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, an alkoxy group having 1 to 12 carbon atoms which may have a substituent, -NR 106 -SiR 107 R 108 R 109 or a group represented by -NR 110 -R 111 and from the viewpoint of enhancing the protective effect on the electrode surface, a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent or a group represented by -NR 106 -SiR 107 R 108 R 109 is more preferred, and -NR 106 -SiR 107 R 108 R 109 is more preferred.

[0069] The halogen atom of Y is R 103 ~R 105 The same explanation as for the halogen atom in the above applies, and the preferred embodiments are also the same.

[0070] The hydrocarbon group having 1 to 12 carbon atoms which may have a substituent on Y is R 103 ~R 105 The same explanations as for the hydrocarbon group having 1 to 12 carbon atoms which may have a substituent are applicable, and the preferred embodiments are also the same.

[0071] The alkoxy group having 1 to 12 carbon atoms which may have a substituent on Y is R103 ~R 105 The same explanations as for the alkoxy group having 1 to 12 carbon atoms which may have a substituent are applicable, and the same preferred embodiments are also applicable.

[0072] Y is -NR 106 -SiR 107 R 108 R 109 When R is a group represented by 106 is a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent. R 106 The hydrocarbon group having 1 to 12 carbon atoms which may have a substituent is R 101 The same explanations as for the hydrocarbon group having 1 to 12 carbon atoms which may have a substituent are applicable, and the preferred embodiments are also the same.

[0073] Y is -NR 106 -SiR 107 R 108 R 109 When R is a group represented by 107 ~R 109 are each independently a hydrogen atom, a halogen atom, an optionally substituted hydrocarbon group of 1 to 12 carbon atoms, or an optionally substituted alkoxy group of 1 to 12 carbon atoms. R 107 ~R 109 The hydrogen atom, halogen atom, hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, or alkoxy group having 1 to 12 carbon atoms which may have a substituent is R 103 ~R 105 The same explanations as for the hydrogen atom, halogen atom, hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, or alkoxy group having 1 to 12 carbon atoms which may have a substituent, respectively, apply, and preferred embodiments are also the same.

[0074] Y is -NR 110 -R 111 When R is a group represented by 110 and R 111 are each independently a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent. R110 and R 111 The hydrocarbon group having 1 to 12 carbon atoms which may have a substituent is R 101 and R 102 The same explanations as for the hydrocarbon group having 1 to 12 carbon atoms which may have a substituent are applicable, and the preferred embodiments are also the same.

[0075] Y is R 101 or R 102 may be bonded to form a ring.

[0076] Examples of the compound (A1) include the following compounds, but are not limited to these compounds.

[0077] [ka]

[0078] [ka]

[0079] [ka]

[0080] [ka]

[0081] From the viewpoint of enhancing the protective effect on the electrode surface, the compound (A1) is preferably the following compound.

[0082] [ka]

[0083] [ka]

[0084] [ka]

[0085] From the viewpoint of further enhancing the protective effect on the electrode surface, the compound (A1) is more preferably the following compound.

[0086] [ka]

[0087] [ka]

[0088] [ka]

[0089] From the viewpoint of further enhancing the protective effect on the electrode surface, the compound (A1) is more preferably the following compound.

[0090] [ka]

[0091] [1-1-2. Compound (A2)] The compound (A2) in this embodiment is represented by the following general formula (2): The compound (A2) may be used alone or in any combination and ratio of two or more kinds.

[0092] [ka]

[0093] (In general formula (2), R 201 ~R 203are each independently a hydrogen atom, an optionally substituted alkyl group having 1 to 10 carbon atoms, an optionally substituted aryl group having 6 to 18 carbon atoms, or an optionally substituted aralkyl group having 7 to 18 carbon atoms, and Z is an optionally substituted alkenyl group or alkynyl group having 2 to 10 carbon atoms.

[0094] R in general formula (2) 201 ~R 203 are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms which may have a substituent, an aryl group having 6 to 18 carbon atoms, or an aralkyl group having 7 to 18 carbon atoms, and from the viewpoint of enhancing the protective effect on the electrode surface, a hydrogen atom or an alkyl group having 1 to 10 carbon atoms which may have a substituent is preferred, and an alkyl group having 1 to 10 carbon atoms which may have a substituent is more preferred. The number of carbon atoms in the alkyl group is 1 to 10, preferably 1 to 8, more preferably 1 to 6, and even more preferably 1 to 4.

[0095] When the optionally substituted alkyl group having 1 to 10 carbon atoms has a substituent, the number of carbon atoms contained in the substituent is not included in the number of carbon atoms of the alkyl group, which is 1 to 10. In other words, the alkyl group may have 1 to 10 carbon atoms as long as it has 1 to 10 carbon atoms in its main chain.

[0096] R 201 ~R 203 When R is an alkyl group having 1 to 10 carbon atoms which may have a substituent, 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. 201 ~R 203 The alkyl group may be used alone or in any combination of two or more kinds in any ratio. R 201 ~R 203From the viewpoint of enhancing the protective effect on the electrode surface, the alkyl groups are each independently preferably a methyl group, an ethyl group, an n-propyl group, an n-butyl group, a tert-butyl group, an n-pentyl group, or a hexyl group, more preferably a methyl group, an ethyl group, an n-propyl group, an n-butyl group, a tert-butyl group, or an n-pentyl group, and even more preferably a methyl group or an ethyl group.

[0097] R 201 ~R 203 Examples of the substituent that the alkyl group may have include a cyano group, an isocyanato group, an acyl group (—(C═O)—R b ), acyloxy group (-O(C=O)-R b ), alkoxycarbonyl group (-(C=O)OR b ), sulfonyl group (-SO2-R b ), sulfonyloxy group (-O(SO2)-R b ), alkoxysulfonyl group (-(SO2)-OR b ), alkoxycarbonyloxy group (-O-(C=O)-OR b ), ether group (-OR b ), an acrylic group, a methacrylic group, a halogen atom (preferably a fluorine atom), a trifluoromethyl group, etc. 201 ~R 203 The substituents of the alkyl group may be used alone or in any combination and ratio of two or more kinds. In addition, R b is 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.

[0098] R b When R is an alkyl group having 1 to 10 carbon atoms, 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. b The alkyl group may be used alone or in any combination of two or more kinds in any ratio. R bFrom the viewpoint of enhancing the protective effect on the electrode surface, the alkyl group is preferably a methyl group, an ethyl group, an n-propyl group, an n-butyl group, a tert-butyl group, an n-pentyl group, or a hexyl group, more preferably a methyl group, an ethyl group, an n-propyl group, an n-butyl group, a tert-butyl group, or an n-pentyl group, and even more preferably a methyl group or an ethyl group.

[0099] R b When R is an alkenyl group having 2 to 10 carbon atoms, 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. b The alkenyl groups may be used alone or in any combination of two or more kinds in any ratio. R b From the viewpoint of enhancing the protective effect on the electrode surface, the alkenyl group is preferably a vinyl group, allyl group, methallyl group or 2-butenyl group, more preferably a vinyl group, allyl group or methallyl group, and even more preferably an allyl group or methallyl group.

[0100] R b When R is an alkynyl group having 2 to 10 carbon atoms, 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. b The alkynyl groups may be used alone or in any combination of two or more kinds in any ratio. R b From the viewpoint of enhancing the protective effect on the electrode surface, the alkynyl group is preferably an ethynyl group, a 2-propynyl group, a 2-butynyl group, or a 3-butynyl group, more preferably an ethynyl group, a 2-propynyl group, or a 3-butynyl group, and even more preferably an ethynyl group or a 2-propynyl group.

[0101] R 201 ~R 203When each of the alkyl groups is an alkyl group having 1 to 10 carbon atoms which may have a substituent, the substituents on the alkyl group are each independently preferably a cyano group, an isocyanato group, an acyl group, an acyloxy group, or an alkoxycarbonyl group, more preferably a cyano group, an isocyanato group, an acyl group, or an alkoxycarbonyl group, still more preferably a cyano group, an isocyanato group, or an alkoxycarbonyl group, and particularly preferably a cyano group, from the viewpoint of enhancing the protective effect on the electrode surface.

[0102] R 201 ~R 203 When R is an aryl group having 6 to 18 carbon atoms, examples of the aryl group include a phenyl group and a tolyl group. 201 ~R 203 The aryl group may be used alone or in any combination of two or more kinds in any ratio. R 201 ~R 203 The aryl group is preferably a phenyl group from the viewpoint of localizing the compound (A2) near the surfaces of the positive electrode active material and the negative electrode active material.

[0103] R 201 ~R 203 When R is an aralkyl group having 7 to 18 carbon atoms, examples of the aralkyl group include a phenylmethyl group (benzyl group), a phenylethyl group (phenethyl group), a phenylpropyl group, a phenylbutyl group, and a phenylisopropyl group. 201 ~R 203 The aralkyl groups may be used alone or in any combination of two or more kinds in any ratio. R 201 ~R 203 From the viewpoint of localizing the compound (A2) near the surfaces of the positive electrode active material and the negative electrode active material, the aralkyl groups are each independently preferably a benzyl group or a phenethyl group, more preferably a benzyl group.

[0104] R 201 ~R 203 From the viewpoint of enhancing the interaction with the siloxane compound (B), R 201 ~R 203At least one of R is preferably an alkyl group having 1 to 10 carbon atoms which may have a substituent, 201 ~R 203 It is more preferable that at least two of R are alkyl groups having 1 to 10 carbon atoms which may have a substituent, 201 ~R 203 It is more preferable that all of R are alkyl groups having 1 to 10 carbon atoms which may have a substituent, 201 ~R 203 It is particularly preferred that all of the groups are methyl or ethyl groups.

[0105] R 201 ~R 203 If one of the is a methyl group, R 201 ~R 203 Not all of R need to be methyl groups. 201 ~R 203 From the viewpoint of enhancing the protective effect on the electrode surface, the following combinations are preferred: (methyl group, methyl group, ethyl group), (methyl group, methyl group, n-butyl group), (methyl group, methyl group, tert-butyl group), (methyl group, methyl group, phenyl group), (methyl group, ethyl group, ethyl group), (methyl group, phenyl group, phenyl group). A combination of all methyl groups is also preferred.

[0106] In general formula (2), Z is an alkenyl or alkynyl group having 2 to 10 carbon atoms, which may have a substituent, and is preferably a vinyl group, allyl group, or methallyl group, more preferably an allyl group or methallyl group, from the viewpoint of enhancing the protective effect on the electrode surface. That is, the composition according to the present embodiment preferably contains, as compound (A2), a compound in which Z in general formula (2) is at least one selected from the group consisting of a vinyl group, an allyl group, and a methallyl group, and more preferably a compound in which Z in general formula (2) is at least one of an allyl group and a methallyl group.

[0107] Examples of the compound (A2) include the following compounds, but are not limited to these compounds.

[0108] [ka]

[0109] The compound (A2) is preferably the following compound from the viewpoint of enhancing the interaction with the siloxane compound (B) and enhancing the protective effect on the electrode surface.

[0110] [ka]

[0111] From the viewpoint of further enhancing the protective effect on the electrode surface, the compound (A2) is more preferably the following compound.

[0112] [ka]

[0113] From the viewpoint of further enhancing the protective effect on the electrode surface, the compound (A2) is more preferably the following compound.

[0114] [ka]

[0115] [1-2. Siloxane Compounds (B)] The siloxane compound (B) in this embodiment is a siloxane compound having 8 or more silicon atoms. Here, the siloxane compound is a compound having a skeleton of silicon and oxygen and having an -Si-O-Si- bond. The number of silicon atoms in the siloxane compound (B) may be 8 or more, preferably 8 to 1000. From the viewpoint of reducing the surface tension of the electrolyte, the number of silicon atoms is preferably 10 or more, more preferably 20 or more, and even more preferably 50 or more. From the viewpoint of suppressing an increase in the viscosity of the electrolyte, the number of silicon atoms is preferably 1000 or less, more preferably 500 or less, and even more preferably 100 or less.

[0116] The siloxane compound (B) in this embodiment is not particularly limited as long as it is a siloxane compound having 8 or more silicon atoms, and examples thereof include silicone and modified silicone. In this embodiment, the siloxane compound (B) may be used alone or in any combination of two or more kinds in any ratio. In this embodiment, the siloxane compound (B) is preferably a modified silicone from the viewpoint of improving wettability to battery components.

[0117] Examples of modified silicones include amino-modified silicone, epoxy-modified silicone, carboxy-modified silicone, carbinol-modified silicone, alkyl-modified silicone, aralkyl-modified silicone, dimethyl silicone, dimethicone, dimethiconol, polyether-modified silicone, polyester-modified silicone, etc. Of these, dimethyl silicone and polyether-modified silicone are preferred.

[0118] Specific examples of the amino-modified silicone include products of DuPont Toray Specialty Materials Co., Ltd., such as "BY 16-205," "FZ-3760," "SF 8417," "BY 16-849," "BY 16-892," "FZ-3785," "BY 16-872," "BY 16-213," "BY 16-203," "BY 16-898," "BY 16-890," "BY 16-891," "BY 16-893," "FZ-3789," "SF 8452C," "SS-3551," "CB-1002 Conditioning Agent," "AP-8087 Fluid," "SM8904 Cosmetic Emulsion," "BY22-079," "FZ-4671," and "FZ-4672."

[0119] Specific examples of the epoxy-modified silicone include products such as "FZ-3720," "BY 16-839," "SF 8411," "SF 8413," "FZ-3736," "BY 16-876," and "SF 8421" manufactured by DuPont Toray Specialty Materials Co., Ltd.

[0120] Specific examples of the carboxy-modified silicone include "BY 16-880" manufactured by DuPont Toray Specialty Materials Co., Ltd.

[0121] Specific examples of the carbinol-modified silicone include "SF 8428" manufactured by DuPont Toray Specialty Materials Co., Ltd.

[0122] Specific examples of the alkyl-modified silicone include products of DuPont Toray Specialty Materials Co., Ltd. such as "BY 16-846," "SF 8416," "SH 203," "SH 230," "SF 8419," "SF 8422," "FS 1265," "SH 510," "SH 550," and "SH 710."

[0123] Specific examples of the aralkyl-modified silicone include "BYK-322" and "BYK-323" manufactured by BYK-Chemie.

[0124] Specific examples of the above dimethyl silicone include DuPont Toray Specialty Materials Co., Ltd. products "SH 200 C Fluid 5 CS," "SH 200 C Fluid 6 CS," "SH 200 C Fluid 10 CS," "SH 200 C Fluid 20 CS," "SH 200 C Fluid 30 CS," "SH 200 C Fluid 50 CS," "SH 200 C Fluid 100 CS," "SH 200 C Fluid 200 CS," "SH 200 C Fluid 350 CS," "SH 200 C Fluid 500 CS," "SH 200 C Fluid 1000 CS," "SH 200 Fluid 3000 CS," "SH 200 C Fluid 5000 CS," "SH 200 Fluid 10000 CS," "SH 200 Fluid 12500 CS," and "SH Examples include "SH 200 Fluid 30000 CS", "SH 200 Fluid 60000 CS", "SH 200 Fluid 100000 CS", and "SH 200 Fluid 1000000 CS".

[0125] Specific examples of the dimethicone include products of DuPont Toray Specialty Materials Co., Ltd. such as "BY 11-003," "BY 11-040," "BY 11-007," "BY 11-014," "BY 11-026," and "BY 25-320."

[0126] Specific examples of the dimethiconol include products of DuPont Toray Specialty Materials Co., Ltd. such as "1501 Fluid," "1503 Fluid," "CB-1556 Fluid," "BY 22-080," "BY 22-007," "FZ-4150," "BY 22-029," "FZ-4188," "BY 22-083," "BY 22-019," "BY 22-020," "BY 22-034," "BY 22-055," and "BY 22-060."

[0127] Specific examples of the polyether-modified silicone include DuPont Toray Specialty Materials Co., Ltd. products such as "FZ-2110," "FZ-2191," "FZ-2166," "FZ-2154," "FZ-2120," "L-720," "SH 8700," "L-7002," "L-7001," "SF 8410," "FZ-2123," "SH 8400," "FZ-2164," "FZ-77," "FZ-2105," "L-7604," "FZ-2104," "FZ-2162," "FZ-2203," "FZ-2207," "FZ-2208," "SH 3771 M," "SH 3772 M," "SH 3773 M," "SH 3775 M," "SH 3749," "ES-5612 Formulation Aid," "SS-2802," "SS-2804," and "BY Examples of suitable cosmetic products include BYK-Chemie's products BYK-300, BYK-302, BYK-306, BYK-307, BYK-325, BYK-330, BYK-331, BYK-333, BYK-342, BYK-345 / 346, BYK-347, BYK-348, BYK-349, BYK-370, BYK-377, BYK-378, and BYK-3455.

[0128] Specific examples of the polyester-modified silicone include BYK-Chemie products "BYK-310," "BYK-313," and "BYK-315."

[0129] The modified silicone may be used alone or in any combination of two or more kinds in any ratio. As the modified silicone, from the viewpoint of suppressing aggregation and local bleeding out in the electrolyte, dimethyl silicone and polyether-modified silicone are preferred, and polyether-modified silicone is more preferred.

[0130] The weight average molecular weight of the siloxane compound (B) in this embodiment is preferably 300 to 100,000. From the viewpoint of reducing the surface tension of the electrolyte, the weight average molecular weight is preferably 300 or more, more preferably 500 or more, and even more preferably 1,000 or more. Furthermore, from the viewpoint of suppressing phase separation, the weight average molecular weight is preferably 100,000 or less, more preferably 50,000 or less, and even more preferably 25,000 or less. In this specification, the weight average molecular weight is measured by gel permeation chromatography (GPC) analysis using a chromatograph equipped with a differential refractive index (RI) and a photodiode array (PDA).

[0131] The siloxane compound (B) preferably does not contain metals, from the viewpoints of being less likely to interact with the hydrophilic group or lipophilic group of the siloxane compound (B), having a high degree of freedom in the electrolyte, and reducing the surface tension of the electrolyte. In this specification, the presence or absence of metals in the siloxane compound (B) is determined by measuring by high-frequency inductively coupled plasma (ICP) atomic emission spectrometry. If the content of metal elements is 1 mass ppm or less, it can be determined that the siloxane compound (B) does not contain metals.

[0132] In order to improve wettability to the positive electrode active material and the negative electrode active material, the siloxane compound (B) in this embodiment preferably contains at least one of a siloxane compound (B1) represented by the following general formula (3) and a siloxane compound (B2) represented by the following general formula (4).

[0133] [ka]

[0134] (In general formula (3), R 301 is an alkyl group having 1 to 3 carbon atoms or a phenyl group, and R 302 is an alkyl group having 1 to 3 carbon atoms, a phenyl group, a polyether group, a carboxylate group, a sulfonate group, a phosphite group, or a phosphate group, and R303 ~R 308 are each independently an alkyl group having 1 to 3 carbon atoms or a phenyl group, n3 is an integer of 6 or more and 100,000 or less, and n3 R 301 and R 302 may be the same or different.)

[0135] [ka]

[0136] (In general formula (4), R 401 is an alkyl group having 1 to 3 carbon atoms or a phenyl group, and R 402 is an alkyl group having 1 to 3 carbon atoms, a phenyl group, a polyether group, a carboxylate group, a sulfonate group, a phosphite group, or a phosphate group, n4 is an integer of 8 or more and 100,000 or less, and n4 R 401 and R 402 may be the same or different.)

[0137] When the viscosity of the electrolyte is high, the siloxane compound (B) preferably contains a siloxane compound (B1) from the viewpoint of improving wettability to battery components such as a positive electrode active material and a negative electrode active material. When the acidity of the electrolyte is high, the siloxane compound (B) preferably contains a siloxane compound (B2) from the viewpoint of improving stability in the electrolyte.

[0138] When the viscosity and acidity of the electrolyte solution are high, the siloxane compound (B) preferably contains a siloxane compound (B1) and a siloxane compound (B2) from the viewpoint of improving wettability and stability to battery components. When the siloxane compound (B1) and the siloxane compound (B2) are used in combination, the mass ratio of the content (mass%) of the siloxane compound (B2) to the content (mass%) of the siloxane compound (B1) in the composition according to this embodiment (content (mass%) of siloxane compound (B2) / content (mass%) of siloxane compound (B1)) is preferably 0.01 to 100. From the viewpoint of improving stability in the electrolyte, this mass ratio is preferably 0.01 or more, more preferably 0.05 or more. Furthermore, from the viewpoint of improving wettability to battery components, this mass ratio is preferably 100 or less, more preferably 20 or less. The ratio can be appropriately determined depending on the application of the composition according to this embodiment and the environment in which the battery is used. When the siloxane compound (B1) or the siloxane compound (B2) contains two or more compounds, the above-mentioned respective contents refer to the total content thereof.

[0139] [1-2-1. Siloxane compounds (B1)] The siloxane compound (B1), which is one aspect of the siloxane compound (B) in this embodiment, is represented by the following general formula (3): The siloxane compound (B1) may be used alone or in any combination and ratio of two or more kinds.

[0140] [ka]

[0141] (In general formula (3), R 301 is an alkyl group having 1 to 3 carbon atoms or a phenyl group, and R 302 is an alkyl group having 1 to 3 carbon atoms, a phenyl group, a polyether group, a carboxylate group, a sulfonate group, a phosphite group, or a phosphate group, and R 303 ~R 308 are each independently an alkyl group having 1 to 3 carbon atoms or a phenyl group, n3 is an integer of 6 or more and 100,000 or less, and n3 R 301 and R 302 may be the same or different.)

[0142] R in general formula (3) 301 may be the same or different in the repeating structure and are alkyl groups having 1 to 3 carbon atoms or phenyl groups. From the viewpoint of suppressing the increase in viscosity of the electrolyte, R 301 is preferably a methyl group or an ethyl group, more preferably a methyl group. For example, when n3 R 301 are more preferably all methyl groups or ethyl groups, and even more preferably all methyl groups.

[0143] R in general formula (3) 302 may be the same or different in the repeating structure and are alkyl groups having 1 to 3 carbon atoms, phenyl groups, polyether groups, carboxylate groups, sulfonate groups, phosphite groups, or phosphate groups. R 302 From the viewpoint of affinity with the electrolyte solution, at least a part of R is preferably a polyether group, a carboxylate group, a sulfonate group, a phosphite group, or a phosphate group. From the viewpoint of affinity with the electrolyte solution and chemical stability due to the formation of hydrogen bonds with the ionic group, R 302 A part of R is more preferably a polyether group, and the polyether group is further preferably a group having a structure represented by the following general formula (5) or a group having a structure represented by the following general formula (6). 302 A part of the above is a polyether group, and the above polyether group is particularly preferably a group having a structure represented by the following general formula (5).

[0144] Above R 302 It is preferable that a part of R is the above group, but n3 R 302 For example, when n3 R 302Among these, 1 to n3 are preferably the above-mentioned polyether group, carboxylate ester group, sulfonate ester group, phosphite ester group, or phosphate ester group, more preferably a polyether group, further preferably at least one of a group having a structure represented by the following general formula (5) and a group having a structure represented by the following general formula (6), and particularly preferably a group having a structure represented by the following general formula (5).

[0145] [ka]

[0146] (In general formula (5), R 501 is an alkylene group having 1 to 3 carbon atoms, n5 is an integer of 1 or more and 1000 or less, and n5 R 501 may be the same or different.)

[0147] [ka]

[0148] (In general formula (6), R 601 is an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms, n6 is an integer of 1 or more and 1000 or less, and n6 R 601 may be the same or different.)

[0149] R in general formula (5) 501 may be the same or different in the repeating structure and is an alkylene group having 1 to 3 carbon atoms. From the viewpoint of reducing the surface tension of the electrolyte, R 501 is preferably an ethylene group or a propylene group, and more preferably an ethylene group. For example, when n5 R 501 are more preferably all ethylene groups or propylene groups, and even more preferably all ethylene groups.

[0150] In general formula (5), n5, which means the number of repetitions of the repeating structure, is an integer of 1 or more and 1000 or less. Here, from the viewpoint of reducing the surface tension of the electrolyte, n5 is preferably 2 or more, and more preferably 3 or more. Furthermore, from the viewpoint of suppressing an increase in the viscosity of the electrolyte, n5 is preferably 500 or less, more preferably 100 or less, even more preferably 90 or less, and particularly preferably 80 or less.

[0151] R in general formula (6) 601 may be the same or different in the repeating structure and are an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms. From the viewpoint of reducing the surface tension of the electrolyte, R 601 is preferably an alkyl group having 1 to 20 carbon atoms, more preferably an alkyl group having 1 to 6 carbon atoms, further preferably a methyl group or an ethyl group, and even more preferably a methyl group. For example, when n6 R 601 are more preferably all methyl groups or ethyl groups, and even more preferably all methyl groups.

[0152] In general formula (6), n6, which means the number of repetitions of the repeating structure, is an integer of 1 or more and 1000 or less. Here, from the viewpoint of reducing the surface tension of the electrolyte, n6 is preferably 2 or more, and more preferably 3 or more. Furthermore, from the viewpoint of suppressing an increase in the viscosity of the electrolyte, n6 is preferably 500 or less, more preferably 100 or less, even more preferably 90 or less, and particularly preferably 80 or less.

[0153] In general formula (3), R 303 ~R 308 are each independently an alkyl group or a phenyl group having 1 to 3 carbon atoms. From the viewpoint of suppressing an increase in the viscosity of the electrolyte, each is preferably independently a methyl group or an ethyl group, and more preferably a methyl group.

[0154] n3, which means the number of repetitions of the repeating structure in general formula (3), is an integer of 6 or more and 100,000 or less. From the viewpoint of thermal stability, n3 is preferably 10 or more, more preferably 100 or more, and even more preferably 500 or more. Furthermore, from the viewpoint of suppressing an increase in the viscosity of the electrolyte, n3 is preferably 50,000 or less, more preferably 10,000 or less, and even more preferably 5,000 or less.

[0155] [1-2-2. Siloxane compounds (B2)] The siloxane compound (B2), which is one aspect of the siloxane compound (B) in this embodiment, is represented by the following general formula (4): The siloxane compound (B2) may be used alone or in any combination and ratio of two or more kinds.

[0156] [ka]

[0157] (In general formula (4), R 401 is an alkyl group having 1 to 3 carbon atoms or a phenyl group, and R 402 is an alkyl group having 1 to 3 carbon atoms, a phenyl group, a polyether group, a carboxylate group, a sulfonate group, a phosphite group, or a phosphate group, n4 is an integer of 8 or more and 100,000 or less, and n4 R 401 and R 402 may be the same or different.)

[0158] R in general formula (4) 401 may be the same or different in the repeating structure and are alkyl groups having 1 to 3 carbon atoms or phenyl groups. R 401 is R in general formula (3) 301 The same explanations and preferred embodiments apply.

[0159] R in general formula (4) 402may be the same or different in the repeating structure and are alkyl groups having 1 to 3 carbon atoms, phenyl groups, polyether groups, carboxylate groups, sulfonate groups, phosphite groups, or phosphate groups. R 402 is R in general formula (3) 302 The same explanations and preferred embodiments apply.

[0160] In general formula (4), n4, which means the number of repetitions of the repeating structure, is an integer of 8 or more and 100,000 or less. From the viewpoint of thermal stability, n4 is preferably 12 or more, more preferably 100 or more, and even more preferably 500 or more. From the viewpoint of suppressing an increase in the viscosity of the electrolyte, n4 is preferably 50,000 or less, more preferably 10,000 or less, and even more preferably 5,000 or less.

[0161] [1-3. Composition of Compound (A) and Siloxane Compound (B)] The composition according to this embodiment contains the compound (A) and a siloxane compound (B). From the viewpoint of simultaneously improving wettability to battery components and suppressing gas generation in an overdischarge state, the combination of compound (A) and siloxane compound (B) is preferably at least one compound selected from the group consisting of compounds (A1) and (A2), which were described above as preferred compounds for compound (A), and at least one siloxane compound (B) selected from the group consisting of dimethyl silicone and polyether-modified silicone, and more preferably at least one compound selected from the group consisting of compounds (A1) as compound (A), and at least one siloxane compound (B) selected from the group consisting of polyether-modified silicone.

[0162] The mass ratio of the content (mass%) of the siloxane compound (B) to the content (mass%) of the compound (A) in the composition according to the present embodiment (siloxane compound (B) content (mass%) / compound (A) content (mass%)) is preferably 0.01 to 1000. From the viewpoint of improving wettability to battery components, the mass ratio is preferably 0.01 or more, and more preferably 0.05 or more. From the viewpoint of suppressing gas generation in an overdischarge state, the mass ratio is preferably 1000 or less, more preferably 500 or less, even more preferably 200 or less, and particularly preferably 100 or less. When compound (A) or siloxane compound (B) contains two or more compounds, the above-mentioned respective contents refer to the total contents thereof.

[0163] Furthermore, when the composition according to this embodiment is used as an insulating film coating, particularly for the purpose of protecting a surface with a high potential, the mass ratio is preferably 0.01 to 10. Here, the mass ratio is preferably 0.01 or more, more preferably 0.05 or more, and even more preferably 0.1 or more, and is preferably 10 or less, more preferably 5 or less, and even more preferably 1 or less. On the other hand, when the composition according to this embodiment is used as an insulating film coating, particularly for the purpose of protecting a surface that is difficult to wet, the mass ratio is preferably 0.5 to 1000. Here, the mass ratio is preferably 0.5 or more, more preferably 1 or more, and even more preferably 2 or more, and is preferably 1000 or less, more preferably 100 or less, and even more preferably 10 or less. The above ratio can be appropriately determined depending on the application of the composition according to this embodiment and the environment in which the battery is used.

[0164] When the composition according to the present embodiment contains compound (A1) and compound (A2), and contains siloxane compound (B1) and siloxane compound (B2) as the siloxane compound (B), it is preferred that the mass ratio represented by {content (% by mass) of compound (A2) / content (% by mass) of compound (A1)} is 0.01 to 100, the mass ratio represented by {content (% by mass) of siloxane compound (B2) / content (% by mass) of siloxane compound (B1)} is 0.01 to 100, and the mass ratio represented by {content (% by mass) of siloxane compound (B) / content (% by mass) of compound (A)} is 0.01 to 1000.

[0165] [1-4.Application] The composition according to the present embodiment may contain other components in addition to the compound (A) and the siloxane compound (B). Examples of such other components include a solvent. The solvent is not particularly limited as long as it dissolves the compound (A) and the siloxane compound (B). The ratio of the compound (A), the ratio of the siloxane compound (B), and the total ratio of the compound (A) and the siloxane compound (B) relative to the solvent are arbitrary.

[0166] The composition according to the present embodiment may be used as an electrolytic solution by further containing, for example, an electrolyte and a non-aqueous solvent described below in addition to the compound (A) and the siloxane compound (B), or may be used as an additive to an electrolytic solution containing an electrolyte and a non-aqueous solvent. When the composition according to this embodiment is used as an electrolyte solution or as an additive to an electrolyte solution, other components that may be contained in the composition include, for example, other compounds described below.

[0167] The composition according to the present embodiment can be suitably used not only as an electrolyte solution but also as an insulating film coating from the viewpoint of forming an insulating film. In particular, from the viewpoint of suppressing gas generation in an overdischarge state, it is particularly preferable to use it as an electrolyte solution, i.e., as an electrolyte solution or as an additive to an electrolyte solution.

[0168] [1-5. Method for producing the composition] The method for producing the composition according to this embodiment includes a step of mixing the compound (A) and the siloxane compound (B). When mixing, the compound (A) and the siloxane compound (B) may be mixed by dissolving them in a solvent.

[0169] The method for dissolving the compound (A) and the siloxane compound (B) in the solvent is not particularly limited. For example, the compound (A) and the siloxane compound (B) may be dissolved in the solvent sequentially or simultaneously. Alternatively, the solution may be diluted or concentrated after dissolution. Furthermore, other components may be added to the solvent.

[0170] [2. Electrolyte] When the composition according to this embodiment is used as an electrolyte solution, the composition further contains an electrolyte and a non-aqueous solvent in addition to the compound (A) and the siloxane compound (B). That is, the electrolyte solution according to this embodiment contains the compound (A), the siloxane compound (B), an electrolyte, and a non-aqueous solvent. When the composition according to the present embodiment contains the compound (A), the siloxane compound (B), an electrolyte, and a non-aqueous solvent, the composition may be used as an electrolytic solution as is, or the concentration of the composition may be further adjusted before use as an electrolytic solution.

[0171] Hereinafter, the case where the composition according to the present embodiment is used as an electrolyte solution will be described. When the composition according to the present embodiment is added as an additive to an electrolyte solution, the electrolyte, non-aqueous solvent, and other compounds contained in the added electrolyte solution may be the same as the electrolyte, non-aqueous solvent, and other compounds described below.

[0172] [2-1. Compound (A)] The compound (A) contained in the electrolyte solution according to this embodiment is similar to the compound (A) in [1-1. Compound (A)], and the preferred embodiments are also similar.

[0173] The content of compound (A) in the composition according to the present embodiment, which is the electrolyte solution, is preferably 0.0001 to 0.2% by mass. From the viewpoint of suppressing gas generation in an overdischarge state, the content is preferably 0.0001% by mass or more, more preferably 0.001% by mass or more, even more preferably 0.01% by mass or more, and particularly preferably 0.05% by mass or more. From the viewpoint of suppressing an increase in the viscosity of the electrolyte solution, the content is preferably 0.2% by mass or less, more preferably 0.1% by mass or less. When two or more compounds are used as compound (A), it is preferable that the total content thereof falls within the above range.

[0174] In this specification, the identification of compound (A) and the content of compound (A) are measured by nuclear magnetic resonance (NMR) analysis. When it is difficult to identify compound (A) or measure the content of compound (A) by nuclear magnetic resonance (NMR) analysis alone, infrared spectroscopy (IR) analysis, gas chromatography (GC) mass spectrometry, or other analyses may be used in combination.

[0175] [2-2. Siloxane Compounds (B)] The siloxane compound (B) contained in the electrolytic solution according to this embodiment is similar to the siloxane compound (B) in [1-2. Siloxane compound (B)], and the preferred embodiments are also similar.

[0176] The content of the siloxane compound (B) in the composition according to this embodiment, which is the electrolyte solution, is preferably 0.0001 to 0.2% by mass. From the viewpoint of improving wettability to battery components, the content is preferably 0.0001% by mass or more, more preferably 0.001% by mass or more, even more preferably 0.005% by mass or more, and particularly preferably 0.01% by mass or more. From the viewpoint of suppressing foaming, the content is preferably 0.2% by mass or less, more preferably 0.15% by mass or less, and even more preferably 0.1% by mass or less. When two or more compounds are used as the siloxane compound (B), the total content thereof preferably falls within the above range.

[0177] In this specification, the identification of the siloxane compound (B) and the content of the siloxane compound (B) are measured by nuclear magnetic resonance (NMR) analysis. If it is difficult to identify the siloxane compound (B) or measure the content of the siloxane compound (B) by nuclear magnetic resonance (NMR) analysis alone, infrared spectroscopy (IR) analysis, gas chromatography (GC) mass spectrometry, or other analyses may be used in combination.

[0178] [2-3. Composition of Compound (A) and Siloxane Compound (B)] The combination of compound (A) and siloxane compound (B) contained in the electrolyte solution according to this embodiment is similar to the combination of compound (A) and siloxane compound (B) in [1-3. Composition of compound (A) and siloxane compound (B)], and preferred embodiments are also similar.

[0179] The mass ratio of the content (mass%) of the siloxane compound (B) to the content (mass%) of the compound (A) in the composition according to the present embodiment, which is an electrolytic solution (siloxane compound (B) content (mass%) / compound (A) content (mass%)) is preferably 0.01 to 1000. From the viewpoint of improving wettability to battery components, the mass ratio is preferably 0.01 or more, and more preferably 0.05 or more. From the viewpoint of suppressing gas generation in an overdischarge state, the mass ratio is preferably 1000 or less, more preferably 500 or less, even more preferably 200 or less, and particularly preferably 100 or less. When compound (A) or siloxane compound (B) contains two or more compounds, the above-mentioned respective contents refer to the total contents thereof.

[0180] [2-4. Electrolytes] The electrolyte in this embodiment is not particularly limited as long as it can be ionized into cations and anions even slightly when dissolved in a solvent. From the viewpoint of increasing solubility, the electrolyte is preferably an alkali metal salt, more preferably a lithium salt, a sodium salt, or a potassium salt, and even more preferably a lithium salt from the viewpoint of improving cycle characteristics. When the electrolyte solution according to this embodiment is used in a lithium ion battery, the counter cation of the electrolyte is preferably a lithium cation. When the electrolyte solution according to this embodiment is used in a sodium ion battery, the counter cation of the electrolyte is preferably a sodium cation. When the electrolyte solution according to this embodiment is used in a potassium ion battery, the counter cation of the electrolyte is preferably a potassium cation.

[0181] Examples of lithium salts include lithium fluoroborate, lithium fluorophosphate, lithium tungstate, lithium carboxylate, lithium sulfonate, lithium imide, lithium methide, lithium oxalate, fluorine-containing organic lithium salt, etc. One type of lithium salt may be used alone, or two or more types may be used in any ratio and combination.

[0182] From the viewpoint of improving low-temperature output characteristics, high-rate charge / discharge characteristics, impedance characteristics, high-temperature storage characteristics, and cycle characteristics, the lithium salts used are: LiBF4 as lithium fluoroborate salt; LiPF6, Li2PO3F, LiPO2F2 as lithium fluorophosphate salt; LiFSO3, CH3SO3Li, CF3SO3Li as lithium sulfonate salt; CH3SO4Li, CF3SO4Li, C2H5SO4Li, C2F5SO4Li, C3H5SO4Li, C3H3SO4Li as lithium sulfate salt; LiN(FSO2)2, LiN(FSO2)(CF3SO2), LiN(CF3SO2)2, LiN(C2F5SO2)2 as lithium imide salt; lithium cyclic 1,2-perfluoroethanedisulfonylimide, lithium cyclic 1,3-perfluoropropanedisulfonylimide; and LiC(FS O2)3, LiC(CF3SO2)3, LiC(C2F5SO2)3; as lithium oxalate salts, lithium difluorooxalatoborate, lithium bis(oxalate)borate, lithium tetrafluorooxalate phosphate, lithium difluorobis(oxalate)phosphate, and lithium tris(oxalate)phosphate are preferred, and from the viewpoint of further improving low-temperature output characteristics, high-rate charge-discharge characteristics, impedance characteristics, high-temperature storage characteristics, and cycle characteristics, LiBF4, LiPF6, LiPO2F2, LiN(FSO2)2, lithium bis(oxalate)borate, LiFSO3, CH3SO4Li, and C2H5SO4Li are more preferred, and from the viewpoint of further improving low-temperature output characteristics, high-rate charge-discharge characteristics, impedance characteristics, high-temperature storage characteristics, and cycle characteristics, LiPF6 is even more preferred.

[0183] Examples of sodium salts include sodium fluoroborates, sodium fluorophosphates, sodium tungstates, sodium carboxylates, sodium sulfonates, sodium imide salts, sodium methide salts, sodium oxalate salts, fluorine-containing organic sodium salts, etc. One type of sodium salt may be used alone, or two or more types may be used in any ratio and combination.

[0184] Sodium salts, from the viewpoint of improving low-temperature output characteristics, high-rate charge / discharge characteristics, impedance characteristics, high-temperature storage characteristics, and cycle characteristics, include sodium fluoroborates such as NaBF4; sodium fluorophosphates such as NaPF6, Na2PO3F, and NaPO2F2; sodium sulfonates such as NaFSO3, CH3SO3Na, and CF3SO3Na; sodium sulfates such as CH3SO4Na, CF3SO4Na, C2H5SO4Na, C2F5SO4Na, C3H5SO4Na, and C3H3SO4Na; sodium imide salts such as NaN(FSO2)2, NaN(FSO2)(CF3SO2), NaN(CF3SO2)2, and NaN(C2F5SO2)2, sodium cyclic 1,2-perfluoroethanedisulfonylimide, and sodium cyclic 1,3-perfluoropropanedisulfonylimide; and sodium methide salts such as NaC( FSO2)3, NaC(CF3SO2)3, NaC(C2F5SO2)3; as sodium oxalate salts, sodium difluorooxalatoborate, sodium bis(oxalate)borate, sodium tetrafluorooxalate phosphate, sodium difluorobis(oxalate)phosphate, and sodium tris(oxalate)phosphate are preferred, and from the viewpoint of further improving low-temperature output characteristics, high-rate charge-discharge characteristics, impedance characteristics, high-temperature storage characteristics, and cycle characteristics, NaBF4, NaPF6, NaPO2F2, NaN(FSO2)2, sodium bis(oxalate)borate, NaFSO3, CH3SO4Na, and C2H5SO4Na are more preferred, and from the viewpoint of further improving low-temperature output characteristics, high-rate charge-discharge characteristics, impedance characteristics, high-temperature storage characteristics, and cycle characteristics, NaPF6 is even more preferred.

[0185] Examples of potassium salts include potassium fluoroborate, potassium fluorophosphate, potassium tungstate, potassium carboxylate, potassium sulfonate, potassium imide, potassium methide, potassium oxalate, fluorine-containing organic potassium salt, etc. One type of potassium salt may be used alone, or two or more types may be used in any ratio and combination.

[0186] Potassium salts, from the viewpoint of improving low-temperature output characteristics, high-rate charge / discharge characteristics, impedance characteristics, high-temperature storage characteristics, and cycle characteristics, are used: potassium fluoroborate salt KBF4; potassium fluorophosphate salt KPF6, K2PO3F, KPO2F2; potassium sulfonate salt KFSO3, CH3SO3K, CF3SO3K; potassium sulfate salt CH3SO4K, CF3SO4K, C2H5SO4K, C2F5SO4K, C3H5SO4K, C3H3SO4K; potassium imide salt KN(FSO2)2, KN(FSO2)(CF3SO2), KN(CF3SO2)2, KN(C2F5SO2)2, potassium cyclic 1,2-perfluoroethanedisulfonylimide, potassium cyclic 1,3-perfluoropropanedisulfonylimide; and potassium methide salt KC(FSO2)3. , KC(CF3SO2)3, KC(C2F5SO2)3; as potassium oxalate salts, potassium difluorooxalatoborate, potassium bis(oxalate)borate, potassium tetrafluorooxalate phosphate, potassium difluorobis(oxalate)phosphate, and potassium tris(oxalate)phosphate are preferred, and from the viewpoint of further improving low-temperature output characteristics, high-rate charge-discharge characteristics, impedance characteristics, high-temperature storage characteristics, and cycle characteristics, KBF4, KPF6, KPO2F2, KN(FSO2)2, potassium bis(oxalate)borate, KFSO3, CH3SO4K, and C2H5SO4K are more preferred, and from the viewpoint of further improving low-temperature output characteristics, high-rate charge-discharge characteristics, impedance characteristics, high-temperature storage characteristics, and cycle characteristics, KPF6 is even more preferred.

[0187] The content of the electrolyte in the composition according to the present embodiment, which is an electrolytic solution, is preferably 5 to 20% by mass. From the viewpoint of improving low-temperature output characteristics, high-rate charge / discharge characteristics, impedance characteristics, high-temperature storage characteristics, and cycle characteristics, the content is preferably 5% by mass or more, more preferably 7% by mass or more, and even more preferably 9% by mass or more. From the viewpoint of improving low-temperature output characteristics, high-rate charge / discharge characteristics, impedance characteristics, high-temperature storage characteristics, and cycle characteristics, the content is preferably 20% by mass or less, more preferably 18% by mass or less, and even more preferably 16% by mass or less. When two or more electrolytes are contained, the content refers to the total content of the electrolytes. In this specification, the identification and content of electrolytes are measured by nuclear magnetic resonance (NMR) analysis. When it is difficult to identify the electrolyte or measure the content of electrolytes by nuclear magnetic resonance (NMR) analysis alone, infrared spectroscopy (IR) analysis, gas chromatography (GC) mass spectrometry, or other analyses may be used in combination.

[0188] When two or more electrolytes are used, it is preferable to combine a first electrolyte with a second electrolyte from the viewpoint of improving low-temperature output characteristics, high-rate charge / discharge characteristics, impedance characteristics, high-temperature storage characteristics, and cycle characteristics.

[0189] The first electrolyte is preferably an electrolyte with a high degree of ionic dissociation that is mainly responsible for carrier transport between electrodes, more preferably LiBF4, LiPF6, or LiN(FSO2)2, further preferably LiPF6 or LiN(FSO2)2, and particularly preferably LiPF6. The second electrolyte is preferably an electrolyte with a low degree of ionic dissociation and primarily responsible for functions other than carrier transport between electrodes, such as forming a coating on the electrode active material, more preferably LiPO2F2, lithium bis(oxalato)borate, LiFSO3, CH3SO4Li, or C2H5SO4Li, even more preferably LiPO2F2, LiFSO3, CH3SO4Li, or C2H5SO4Li, and particularly preferably LiPO2F2 or LiFSO3.

[0190] The combination of the first electrolyte and the second electrolyte may be selected appropriately based on the degree of ionization of the electrolytes and their effects, and examples thereof include LiPF6 and LiPO2F2, LiPF6 and lithium bis(oxalato)borate, LiPF6 and LiFSO3, LiPF6 and CH3SO4Li, LiPF6 and C2H5SO4Li, LiN(FSO2)2 and LiPO2F2, LiN(FSO2)2 and lithium bis(oxalato)borate, LiN(FSO2)2 and LiFSO3, LiN(FSO2)2 and CH3SO4Li, LiN(FSO2)2 and C2H5SO4Li, etc. From the viewpoint of improving low-temperature output characteristics, high-rate charge / discharge characteristics, impedance characteristics, high-temperature storage characteristics, and cycle characteristics, the combinations of the first electrolyte and the second electrolyte are preferably LiPF6 and LiPO2F2, LiPF6 and LiFSO3, LiPF6 and CH3SO4Li, LiPF6 and C2H5SO4Li, LiN(FSO2)2 and LiPO2F2, LiN(FSO2)2 and LiFSO3, LiN(FSO2)2 and CH3SO4Li, and LiN(FSO2)2 and C2H5SO4Li, and more preferably LiPF6 and LiPO2F2, LiPF6 and LiFSO3, LiN(FSO2)2 and LiPO2F2, and LiN(FSO2)2 and LiFSO3.

[0191] The content of the first electrolyte in the composition according to the present embodiment, which is an electrolytic solution, is preferably 4 to 19% by mass. From the viewpoint of improving low-temperature output characteristics, high-rate charge / discharge characteristics, impedance characteristics, high-temperature storage characteristics, and cycle characteristics, the content is preferably 4% by mass or more, more preferably 6% by mass or more, and even more preferably 8% by mass or more. From the viewpoint of improving low-temperature output characteristics, high-rate charge / discharge characteristics, impedance characteristics, high-temperature storage characteristics, and cycle characteristics, the content is preferably 19% by mass or less, more preferably 17% by mass or less, and even more preferably 15% by mass or less. When two or more first electrolytes are contained, the content refers to the total content of the first electrolytes.

[0192] The content of the second electrolyte in the composition according to the present embodiment, which is an electrolytic solution, is preferably 0.001 to 5% by mass. From the viewpoints of improving the DC resistance retention rate after high-temperature storage and the effect of suppressing gas generation after high-temperature storage, the content is preferably 0.001% by mass or more, more preferably 0.01% by mass or more, and even more preferably 0.1% by mass or more. From the viewpoints of improving the DC resistance retention rate after high-temperature storage and the effect of suppressing gas generation after high-temperature storage, the content is preferably 5% by mass or less, more preferably 4% by mass or less, and even more preferably 3% by mass or less. When two or more second electrolytes are included, the content refers to the total content of the second electrolytes.

[0193] The mass ratio of the first electrolyte to the second electrolyte (content (mass%) of the second electrolyte / content (mass%) of the first electrolyte) is preferably 0.0001 to 0.5. From the viewpoints of improving the DC resistance retention rate after high-temperature storage and the effect of suppressing gas generation after high-temperature storage, the mass ratio is preferably 0.0001 or more, more preferably 0.001 or more, and even more preferably 0.01 or more. From the viewpoints of improving the DC resistance retention rate after high-temperature storage and the effect of suppressing gas generation after high-temperature storage, the mass ratio is preferably 0.5 or less, more preferably 0.4 or less, and even more preferably 0.3 or less. The ratio can be appropriately determined depending on the application of the composition according to this embodiment and the environment in which the battery is used. When the first electrolyte or the second electrolyte contains two or more compounds, the above-mentioned respective contents refer to the total contents of those compounds.

[0194] [2-5. Non-aqueous solvents] The non-aqueous solvent in this embodiment is not particularly limited as long as it is a non-aqueous solvent that dissolves the compound (A), the siloxane compound (B), and the electrolyte. From the viewpoint of suppressing oxidation-reduction decomposition in the battery, the non-aqueous solvent is preferably an organic solvent.

[0195] Examples of the organic solvent include saturated cyclic carbonates, chain carbonates, chain carboxylic acid esters, cyclic carboxylic acid esters, ether compounds, sulfone compounds, etc. One type of organic solvent may be used alone, or two or more types may be used in any ratio and combination. From the viewpoint of suppressing oxidation-reduction decomposition in the battery, the organic solvent is preferably a saturated cyclic carbonate, a chain carbonate, a chain carboxylic acid ester, a cyclic carboxylic acid ester, an ether-based compound, or a sulfone-based compound, and more preferably a saturated cyclic carbonate, a chain carbonate, or a chain carboxylic acid ester.

[0196] Examples of combinations of two or more organic solvents 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 saturated cyclic carbonate and a cyclic carboxylic acid ester, 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. From the viewpoint of improving low-temperature output characteristics, high-rate charge / discharge characteristics, impedance characteristics, high-temperature storage characteristics, and cycle characteristics, preferred combinations of two or more organic solvents are 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.

[0197] The content of the non-aqueous solvent in the composition according to the present embodiment, which is an electrolytic solution, is preferably 84 to 95% by mass. From the viewpoint of improving low-temperature output characteristics, high-rate charge / discharge characteristics, impedance characteristics, high-temperature storage characteristics, and cycle characteristics, the content is preferably 84% by mass or more, more preferably 86% by mass or more, and even more preferably 88% by mass or more. From the viewpoint of improving low-temperature output characteristics, high-rate charge / discharge characteristics, impedance characteristics, high-temperature storage characteristics, and cycle characteristics, the content is preferably 95% by mass or less, more preferably 93% by mass or less, and even more preferably 91% by mass or less. When two or more non-aqueous solvents are contained, the content refers to the total content of the solvents. In this specification, the identification of the non-aqueous solvent and the content of the non-aqueous solvent are measured by nuclear magnetic resonance (NMR) analysis. When it is difficult to identify the non-aqueous solvent or measure the content of the non-aqueous solvent by nuclear magnetic resonance (NMR) analysis alone, infrared spectroscopy (IR) analysis, gas chromatography (GC) mass spectrometry, or other analyses may be used in combination.

[0198] [2-5-1. Saturated cyclic carbonates] Examples of saturated cyclic carbonates that serve as the non-aqueous solvent in this embodiment include ethylene carbonate, propylene carbonate, butylene carbonate, erythritol bis(carbonate), etc. The saturated cyclic carbonates may be used alone or in any combination and ratio. As the saturated cyclic carbonate, ethylene carbonate and propylene carbonate are preferred, and ethylene carbonate is more preferred, from the viewpoint of improving the degree of ionic dissociation of the alkali metal.

[0199] When a saturated cyclic carbonate is used as the nonaqueous solvent, the content of the saturated cyclic carbonate relative to the total nonaqueous solvent is preferably 3 to 90% by volume. From the viewpoints of suppressing a decrease in electrical conductivity due to a decrease in the dielectric constant of the electrolyte and improving large-current discharge characteristics, stability with respect to the negative electrode, cycle characteristics, oxidation-reduction resistance of the electrolyte, and high-temperature storage characteristics, the content is preferably 3% by volume or more, more preferably 5% by volume or more, and even more preferably 10% by volume or more. Furthermore, from the viewpoints of suppressing a decrease in electrical conductivity due to a decrease in the dielectric constant of the electrolyte and improving large-current discharge characteristics, stability with respect to the negative electrode, cycle characteristics, oxidation-reduction resistance of the electrolyte, and high-temperature storage characteristics, the content is preferably 90% by volume or less, more preferably 85% by volume or less, and even more preferably 80% by volume or less. When two or more saturated cyclic carbonates are used, the content refers to the total content of the saturated cyclic carbonates. In this specification, the term "volume %" refers to the volume ratio at 25°C and 1 atmosphere.

[0200] [2-5-2. Chain carbonate] Examples of the chain carbonate that serves as the non-aqueous solvent in this embodiment include dimethyl carbonate, diethyl carbonate, di-n-propyl carbonate, diisopropyl carbonate, n-propylisopropyl carbonate, ethyl methyl carbonate, methyl-n-propyl carbonate, methyl phenyl carbonate, methyl-2,2,2-trifluoroethyl carbonate, etc. One type of chain carbonate may be used alone, or two or more types may be used in any ratio and combination. From the viewpoint of suppressing an increase in the viscosity of the electrolyte solution, the chain carbonate is preferably a chain carbonate having 3 to 5 carbon atoms, and more preferably dimethyl carbonate, diethyl carbonate, or ethyl methyl carbonate.

[0201] When a chain carbonate is used as the non-aqueous solvent, the content of the chain carbonate relative to the total non-aqueous solvent is preferably 15 to 90% by volume. From the viewpoints of ensuring that the viscosity of the electrolyte solution is in an appropriate range, suppressing a decrease in ion conductivity, and achieving favorable battery output characteristics, 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. Furthermore, from the viewpoints of ensuring that the viscosity of the electrolyte solution is in an appropriate range, suppressing a decrease in ion conductivity, and achieving favorable battery output characteristics, the content is preferably 90% by volume or less, more preferably 85% by volume or less, and even more preferably 80% by volume or less. When two or more chain carbonates are used, the content refers to the total content of the chain carbonates.

[0202] In the present embodiment, the nonaqueous solvent is preferably a combination of ethylene carbonate and a chain carbonate, and more preferably a combination of ethylene carbonate, dimethyl carbonate, and ethyl methyl carbonate, from the viewpoints of suppressing an increase in the viscosity of the electrolyte solution and improving the electrical conductivity.

[0203] When ethylene carbonate, dimethyl carbonate, and ethyl methyl carbonate are used as the non-aqueous solvent, the content of ethylene carbonate relative to the total non-aqueous solvent is preferably 15 to 45% by volume. From the viewpoint of improving the rate characteristics resulting from the improvement in the degree of ionic dissociation, the content is preferably 15% by volume or more, more preferably 20% by volume or more. Also, from the viewpoint of improving the rate characteristics resulting from the improvement in the degree of ionic dissociation, the content is preferably 45% by volume or less, more preferably 40% by volume or less.

[0204] When ethylene carbonate, dimethyl carbonate, and ethyl methyl carbonate are used as the non-aqueous solvent, the content of dimethyl carbonate relative to the total non-aqueous solvent is preferably 20 to 50% by volume. From the viewpoint of suppressing an increase in the viscosity of the electrolyte, the content is preferably 20% by volume or more, more preferably 30% by volume or more. Furthermore, from the viewpoint of improving the low-temperature characteristics of the battery, the content is preferably 50% by volume or less, more preferably 45% by volume or less.

[0205] When ethylene carbonate, dimethyl carbonate, and ethyl methyl carbonate are used as the nonaqueous solvent, the content of ethyl methyl carbonate relative to the total nonaqueous solvent is preferably 20 to 50% by volume. From the viewpoints of ensuring an appropriate range for the viscosity of the electrolyte, suppressing a decrease in ion conductivity, and achieving favorable battery output characteristics, the content is preferably 20% by volume or more, and more preferably 30% by volume or more. Furthermore, from the viewpoints of ensuring an appropriate range for the viscosity of the electrolyte, suppressing a decrease in ion conductivity, and achieving favorable battery output characteristics, the content is preferably 50% by volume or less, and more preferably 45% by volume or less.

[0206] [2-5-3. Chain carboxylic acid esters] Examples of the chain carboxylic acid ester that can be used as 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, methyl pivalate, etc. One type of chain carboxylic acid ester may be used alone, or two or more types may be used in any ratio and combination. As the chain carboxylic acid ester, from the viewpoints of ensuring that the viscosity of the electrolyte solution falls within an appropriate range, suppressing a decrease in ionic conductivity, and ensuring that the output characteristics of the battery fall within a favorable range, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, and propyl propionate are preferred, and methyl acetate, ethyl acetate, and methyl propionate are more preferred.

[0207] The chain carboxylic acid ester may be a chain carboxylic acid ester in which some of the hydrogen atoms have been substituted with fluorine atoms. Examples of the fluorine-substituted chain carboxylic acid ester include methyl trifluoroacetate, ethyl trifluoroacetate, 2,2-difluoroethyl acetate, 2,2,2-trifluoroethyl acetate, etc. The fluorine-substituted chain carboxylic acid ester may be used alone or in any combination and ratio. The fluorine-substituted chain carboxylic acid ester is preferably methyl trifluoroacetate or ethyl trifluoroacetate, more preferably methyl trifluoroacetate, from the viewpoint of suppressing an increase in the viscosity of the electrolyte.

[0208] When a chain carboxylic acid ester is used as the nonaqueous solvent, the content of the chain carboxylic acid ester relative to the total nonaqueous solvent is preferably 5 to 70% by volume. From the viewpoint of improving the electrical conductivity of the electrolyte and enhancing the large-current discharge characteristics of the battery, 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 viewpoint of keeping the viscosity of the electrolyte within an appropriate range, suppressing a decrease in electrical conductivity, suppressing an increase in negative electrode resistance, and achieving favorable large-current discharge characteristics of the battery, 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. When two or more chain carboxylic acid esters are used, the content refers to the total content of the chain carboxylic acid esters.

[0209] [2-5-4. Cyclic carboxylic acid esters] Examples of the cyclic carboxylic acid ester that can be used as the non-aqueous solvent in this embodiment include γ-butyrolactone, γ-valerolactone, etc. One type of cyclic carboxylic acid ester may be used alone, or two or more types may be used in any ratio and combination. The cyclic carboxylic acid ester is preferably γ-butyrolactone from the viewpoint of improving electrical conductivity.

[0210] The cyclic carboxylic acid ester may be a cyclic carboxylic acid ester in which some of the hydrogen atoms have been substituted with fluorine atoms. Examples of the fluorine-substituted cyclic carboxylic acid ester include 3-fluorotetrahydrofuran-2-one, 4-fluorotetrahydrofuran-2-one, etc. One type of fluorine-substituted cyclic carboxylic acid ester may be used alone, or two or more types may be used in any ratio and combination. The fluorine-substituted cyclic carboxylic acid ester is preferably 3-fluorotetrahydrofuran-2-one from the viewpoint of improving oxidation resistance.

[0211] When a cyclic carboxylic acid ester is used as the nonaqueous solvent, the content of the cyclic carboxylic acid ester relative to the total nonaqueous solvent is preferably 1 to 70% by volume. From the viewpoint of improving the electrical conductivity of the electrolyte and enhancing the large-current discharge characteristics of the battery, 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. From the viewpoint of keeping the viscosity of the electrolyte within an appropriate range, suppressing a decrease in electrical conductivity, suppressing an increase in negative electrode resistance, and achieving favorable large-current discharge characteristics of the battery, 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. When two or more cyclic carboxylic acid esters are used, the content refers to the total content of the cyclic carboxylic acid esters.

[0212] [2-5-5. Ether compounds] Examples of ether-based compounds that can be used as non-aqueous solvents 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. The ether-based compound may be an ether-based compound in which some of the hydrogen atoms are substituted with fluorine atoms. One type of ether-based compound may be used alone, or two or more types may be used in any ratio and combination.

[0213] The ether-based compound is preferably a chain ether having 3 to 10 carbon atoms or a cyclic ether having 3 to 6 carbon atoms, from the viewpoint of suppressing an increase in the viscosity of the electrolyte solution. Among the chain ethers having 3 to 10 carbon atoms, dimethoxymethane, diethoxymethane, and ethoxymethoxymethane are preferred from the viewpoints of high solvation ability for lithium ions, improved ion dissociation, suppression of an increase in the viscosity of the electrolyte, and improved ionic conductivity. The cyclic ether having 3 to 6 carbon atoms is preferably tetrahydrofuran, 1,3-dioxane, or 1,4-dioxane, from the viewpoint of improving ionic conductivity.

[0214] When an ether-based compound is used as the non-aqueous solvent, the content of the ether-based compound relative to the total non-aqueous solvent is preferably 1 to 30% by volume. From the viewpoints of ensuring that the viscosity of the electrolyte solution is in an appropriate range, suppressing a decrease in ion conductivity, and achieving favorable battery output characteristics, the content is preferably 1% by volume or more, more preferably 2% by volume or more, and even more preferably 3% by volume or more. Furthermore, from the viewpoints of ensuring that the viscosity of the electrolyte solution is in an appropriate range, suppressing a decrease in ion conductivity, and achieving favorable battery output characteristics, the content is preferably 30% by volume or less, more preferably 25% by volume or less, and even more preferably 20% by volume or less. When two or more ether-based compounds are contained, the content refers to the total content of the compounds.

[0215] [2-5-6. Sulfone compounds] The sulfone-based compound serving as the non-aqueous solvent in this embodiment may be a cyclic sulfone or a chain sulfone. The sulfone-based compound may be used alone or in any combination and ratio of two or more kinds. The number of sulfonyl groups in the sulfone-based compound is preferably 1 to 2, and more preferably 1, from the viewpoint of improving ionic conductivity.

[0216] Examples of the cyclic sulfone include monosulfone compounds such as trimethylene sulfones, tetramethylene sulfones (sulfolanes), and hexamethylene sulfones; and disulfone compounds such as trimethylene disulfones, tetramethylene disulfones, and hexamethylene disulfones. One type of cyclic sulfone may be used alone, or two or more types may be used in any ratio and combination. From the viewpoint of suppressing an increase in the viscosity of the electrolyte, the cyclic sulfone is preferably a cyclic sulfone having 3 to 6 carbon atoms, more preferably a chain sulfone having 3 to 5 carbon atoms, and further preferably a sulfolanes.

[0217] Examples of sulfolanes include sulfolane and sulfolane derivatives such as 2-methylsulfolane, 3-methylsulfolane, 2-fluorosulfolane, 3-fluorosulfolane, 2,3-difluorosulfolane, 2-trifluoromethylsulfolane, and 3-trifluoromethylsulfolane. One type of sulfolanes may be used alone, or two or more types may be used in any ratio and combination. As the sulfolanes, from the viewpoint of improving ionic conductivity, sulfolane and sulfolane derivatives are preferred, and sulfolane, 2-methylsulfolane, 3-methylsulfolane, 2-fluorosulfolane, 3-fluorosulfolane, 2,3-difluorosulfolane, 2-trifluoromethylsulfolane, and 3-trifluoromethylsulfolane are more preferred.

[0218] From the viewpoint of improving oxidation resistance, the sulfolane derivative is preferably a sulfolane derivative in which one or more hydrogen atoms bonded to the carbon atoms constituting the sulfolane ring are substituted with a fluorine atom, a sulfolane derivative in which one or more hydrogen atoms bonded to the carbon atoms constituting the sulfolane ring are substituted with an alkyl group, or a sulfolane derivative in which one or more hydrogen atoms bonded to the carbon atoms constituting the sulfolane ring are substituted with a fluorine-substituted alkyl group, with 2-methylsulfolane, 3-methylsulfolane, 2-fluorosulfolane, 3-fluorosulfolane, 2,3-difluorosulfolane, 2-trifluoromethylsulfolane, and 3-trifluoromethylsulfolane being more preferred.

[0219] 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. The chain sulfone may be used alone or in any combination and ratio of two or more kinds. From the viewpoint of improving the high-temperature storage stability of the electrolyte solution, the chain sulfone is preferably a chain sulfone having 2 to 6 carbon atoms, more preferably a chain sulfone having 2 to 5 carbon atoms, and further preferably dimethyl sulfone, ethyl methyl sulfone, or monofluoromethyl methyl sulfone.

[0220] When a sulfone compound is used as the non-aqueous solvent, the content of the sulfone compound relative to the total non-aqueous solvent is preferably 0.3 to 40% by volume. From the viewpoints of ensuring an appropriate range for the viscosity of the electrolyte, suppressing a decrease in ionic conductivity, and achieving favorable battery output characteristics, 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. Furthermore, from the viewpoints of ensuring an appropriate range for the viscosity of the electrolyte, suppressing a decrease in ionic conductivity, and achieving favorable battery output characteristics, the content is preferably 40% by volume or less, more preferably 35% by volume or less, and even more preferably 30% by volume or less. When two or more sulfone compounds are used, the content refers to the total content of the compounds.

[0221] [2-6. Other compounds] The composition according to the present embodiment that serves as the electrolytic solution may contain compounds other than the compound (A), the siloxane compound (B), the electrolyte, and the non-aqueous solvent, as long as the effects of the present invention are not significantly impaired.

[0222] Examples of the other compounds include unsaturated cyclic carbonates, fluorine-containing cyclic carbonates, isocyanate group-containing organic compounds, isocyanuric acid skeleton-containing organic compounds, sulfur-containing organic compounds, phosphorus-containing organic compounds, silicon-containing compounds, aromatic compounds, cyano group-containing organic compounds, acid anhydride compounds, triple bond-containing compounds, etc. One type of the other compounds may be used alone, or two or more types may be used in any ratio and combination. From the viewpoint of improving low-temperature output characteristics, high-rate charge / discharge characteristics, impedance characteristics, high-temperature storage characteristics, and cycle characteristics, the other compounds are preferably unsaturated cyclic carbonates, fluorine-containing cyclic carbonates, isocyanate group-containing organic compounds, isocyanuric acid skeleton-containing organic compounds, sulfur-containing organic compounds, phosphorus-containing organic compounds, silicon-containing compounds, aromatic compounds, cyano group-containing organic compounds, acid anhydride compounds, and triple bond-containing compounds, more preferably unsaturated cyclic carbonates, fluorine-containing cyclic carbonates, isocyanate group-containing organic compounds, and isocyanuric acid skeleton-containing organic compounds, and even more preferably unsaturated cyclic carbonates and fluorine-containing cyclic carbonates.

[0223] The total content of other compounds in the composition according to the present embodiment, which is an electrolyte solution, is preferably 0.1 to 20% by mass. From the viewpoint of improving low-temperature output characteristics, high-rate charge / discharge characteristics, impedance characteristics, high-temperature storage characteristics, and cycle characteristics, the total content is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, and even more preferably 0.5% by mass or more. From the viewpoint of improving low-temperature output characteristics, high-rate charge / discharge characteristics, impedance characteristics, high-temperature storage characteristics, and cycle characteristics, the content is preferably 20% by mass or less, more preferably 15% by mass or less, and even more preferably 10% by mass or less. In this specification, the identification and content of other compounds are measured by nuclear magnetic resonance (NMR) analysis. When it is difficult to identify or measure the content of other compounds by nuclear magnetic resonance (NMR) analysis alone, infrared spectroscopy (IR) analysis, gas chromatography (GC) mass spectrometry, or other analysis may be used in combination.

[0224] [2-6-1. Unsaturated cyclic carbonates] Examples of the unsaturated cyclic carbonate that can be used as another compound in this embodiment include vinylene carbonates, ethylene carbonates substituted with a substituent having an aromatic ring, a carbon-carbon double bond, or a carbon-carbon triple bond, phenyl carbonates, vinyl carbonates, allyl carbonates, catechol carbonates, etc. One type of unsaturated cyclic carbonate may be used alone, or two or more types may be used in any ratio and combination. From the viewpoint of improving low-temperature output characteristics, high-rate charge / discharge characteristics, impedance characteristics, high-temperature storage characteristics, and cycle characteristics, the unsaturated cyclic carbonate is preferably a vinylene carbonate or an ethylene carbonate substituted with a substituent having an aromatic ring, a carbon-carbon double bond, or a carbon-carbon triple bond, and more preferably a vinylene carbonate.

[0225] Examples of vinylene carbonates include vinylene carbonate, methyl vinylene carbonate, 4,5-dimethyl vinylene carbonate, phenyl vinylene carbonate, 4,5-diphenyl vinylene carbonate, vinyl vinylene carbonate, 4,5-vinyl vinylene carbonate, allyl vinylene carbonate, 4,5-diallyl vinylene carbonate, etc. One type of vinylene carbonate may be used alone, or two or more types may be used in any ratio and combination.

[0226] Examples of ethylene carbonates substituted with a substituent having an aromatic ring, a carbon-carbon double bond, or a carbon-carbon triple bond include vinyl ethylene carbonate, 4,5-divinyl ethylene carbonate, 4-methyl-5-vinyl ethylene carbonate, 4-allyl-5-vinyl ethylene carbonate, ethynyl ethylene carbonate, 4,5-diethynyl ethylene carbonate, 4-methyl-5-ethynyl ethylene carbonate, 4-vinyl-5-ethynyl ethylene carbonate, 4-allyl-5-ethynyl ethylene carbonate, phenyl ethylene carbonate, 4,5-diphenyl ethylene carbonate, 4-phenyl-5-vinyl ethylene carbonate, 4-allyl-5-phenyl ethylene carbonate, allyl ethylene carbonate, 4,5-diallyl ethylene carbonate, and 4-methyl-5-allyl ethylene carbonate. The ethylene carbonates substituted with a substituent having an aromatic ring, a carbon-carbon double bond or a carbon-carbon triple bond may be used alone or in any combination and ratio of two or more kinds.

[0227] As the unsaturated cyclic carbonate, from the viewpoint of improving low-temperature output characteristics, high-rate charge / discharge characteristics, impedance characteristics, high-temperature storage characteristics, and cycle characteristics, vinylene carbonate, vinylethylene carbonate, and ethynylethylene carbonate are preferred, vinylene carbonate and vinylethylene carbonate are more preferred, and vinylene carbonate is even more preferred.

[0228] [2-6-2. Fluorine-containing cyclic carbonates] Examples of the fluorine-containing cyclic carbonate that serves as the other compound in this embodiment include fluorine-containing cyclic carbonates having an alkylene group having 2 to 6 carbon atoms, such as fluorine-containing ethylene carbonate, and derivatives of fluorine-containing cyclic carbonates having an alkylene group having 2 to 6 carbon atoms, such as fluorine-containing ethylene carbonate substituted with an alkyl group having 1 to 4 carbon atoms. One type of fluorine-containing cyclic carbonate may be used alone, or two or more types may be used in any ratio and combination. From the viewpoint of improving low-temperature output characteristics, high-rate charge / discharge characteristics, impedance characteristics, high-temperature storage characteristics, and cycle characteristics, the fluorine-containing cyclic carbonate is preferably fluoroethylene carbonate having 1 to 4 fluorine atoms, a derivative of fluoroethylene carbonate having 1 to 8 fluorine atoms, or ethylene carbonate having a fluorine-containing group.

[0229] Examples of fluoroethylene carbonates having 1 to 4 fluorine atoms, derivatives of fluoroethylene carbonates having 1 to 8 fluorine atoms, and ethylene carbonates having a fluorine-containing group include monofluoroethylene carbonate, 4,4-difluoroethylene carbonate, 4,5-difluoroethylene carbonate, 4-fluoro-4-methylethylene carbonate, 4,5-difluoro-4-methylethylene carbonate, 4-fluoro-5-methylethylene carbonate, 4,4-difluoro-5-methylethylene carbonate, Examples of suitable ethylene carbonates include 4-fluoroethylene carbonate, 4-(fluoromethyl)-ethylene carbonate, 4-(difluoromethyl)-ethylene carbonate, 4-(trifluoromethyl)-ethylene carbonate, 4-(fluoromethyl)-4-fluoroethylene carbonate, 4-(fluoromethyl)-5-fluoroethylene carbonate, 4-fluoro-4,5-dimethylethylene carbonate, 4,5-difluoro-4,5-dimethylethylene carbonate, and 4,4-difluoro-5,5-dimethylethylene carbonate. Fluoroethylene carbonates having 1 to 4 fluorine atoms, derivatives of fluoroethylene carbonates having 1 to 8 fluorine atoms, and ethylene carbonates having a fluorine-containing group may be used alone or in any combination and ratio. Of the fluoroethylene carbonates having 1 to 4 fluorine atoms, derivatives of fluoroethylene carbonates having 1 to 8 fluorine atoms, and ethylene carbonates having a fluorine-containing group, monofluoroethylene carbonate, 4,4-difluoroethylene carbonate, and 4,5-difluoroethylene carbonate are preferred from the viewpoint of improving low-temperature output characteristics, high-rate charge / discharge characteristics, impedance characteristics, high-temperature storage characteristics, and cycle characteristics.

[0230] [2-6-3. Isocyanate group-containing organic compounds] The number of isocyanate groups in the isocyanate group-containing organic compound that is the other compound in this embodiment is preferably 1 to 4, more preferably 2 to 3, and even more preferably 2, from the viewpoint of improving low-temperature output characteristics, high-rate charge / discharge characteristics, impedance characteristics, high-temperature storage characteristics, and cycle characteristics.

[0231] Examples of isocyanate group-containing organic compounds include monoisocyanate compounds such as methyl isocyanate, ethyl isocyanate, butyl isocyanate, vinyl isocyanate, propargyl isocyanate, cyclohexyl isocyanate, phenyl isocyanate, 2-isocyanatoethyl acrylate, and 2-isocyanatoethyl methacrylate; and diisocyanate compounds such as monomethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, octamethylene diisocyanate, 1,4-phenylene diisocyanate, 1,3-diisocyanatopropane, 1,3-bis(isocyanatomethyl)cyclohexane, carbonyl diisocyanate, and 1,4-diisocyanato-2-fluorobutane. These isocyanate group-containing organic compounds may be used alone or in any combination and ratio. From the viewpoint of improving low-temperature output characteristics, high-rate charge / discharge characteristics, impedance characteristics, high-temperature storage characteristics, and cycle characteristics, the isocyanate group-containing organic compound is preferably a diisocyanate compound, more preferably hexamethylene diisocyanate or 1,3-bis(isocyanatomethyl)cyclohexane, and even more preferably 1,3-bis(isocyanatomethyl)cyclohexane.

[0232] [2-6-4. Organic compounds containing isocyanuric acid skeleton] Examples of the isocyanuric acid skeleton-containing organic compound that serves as the other compound in this embodiment include the following compounds.

[0233] [ka]

[0234] The isocyanuric acid skeleton-containing organic compound may be used alone or in any combination of two or more kinds in any ratio. From the viewpoint of improving low-temperature output characteristics, high-rate charge / discharge characteristics, impedance characteristics, high-temperature storage characteristics, and cycle characteristics, the isocyanuric acid skeleton-containing organic compound is preferably an isocyanurate compound having a saturated or unsaturated aliphatic hydrocarbon group which may have a halogen atom, more preferably an isocyanurate compound having an unsaturated aliphatic hydrocarbon group having a terminal carbon-carbon unsaturated bond, and even more preferably triallyl isocyanurate.

[0235] [2-6-5. Sulfur-containing organic compounds] The sulfur-containing organic compound serving as the other compound in this embodiment is preferably an organic compound having at least one S═O bond, from the viewpoint of improving low-temperature output characteristics, high-rate charge / discharge characteristics, impedance characteristics, high-temperature storage characteristics, and cycle characteristics, and is more preferably a chain sulfonate ester, a cyclic sulfonate ester, a chain sulfate ester, a cyclic sulfate ester, a chain sulfite ester, or a cyclic sulfite ester.

[0236] Examples of sulfur-containing organic compounds include chain sulfonate esters such as alkyl disulfonates, such as methyl fluorosulfonate, methyl methanesulfonate, ethyl methanesulfonate, propargyl methanesulfonate, busulfan, methyl methanesulfonyloxyacetate, methyl vinylsulfonate, allyl vinylsulfonate, propargyl allylsulfonate, methoxycarbonylmethyl methanedisulfonate, ethoxycarbonylmethyl methanedisulfonate, methoxycarbonylmethyl 1,3-butanedisulfonate, ethoxycarbonylmethyl 1,3-butanedisulfonate, 1-methoxycarbonylethyl 1,3-butanedisulfonate, 1-ethoxycarbonylethyl 1,3-butanedisulfonate, and hexafluorophenyl methanesulfonate; 1,3-propanesultone, 1-fluoro-1,3-propanesultone, and 1-fluoro-1,3-propanesultone. Cyclic sulfonic acid esters such as pansultone, 1-methyl-1,3-propane sultone, 1-propene-1,3-sultone, 2-propene-1,3-sultone, 1-fluoro-1-propene-1,3-sultone, 1-methyl-1-propene-1,3-sultone, 1,3-butane sultone, 2,4-butane sultone, 1,4-butane sultone, 1,5-pentane sultone, methylenemethane disulfonate, ethylenemethane disulfonate, and 2,2-dioxide-1,2-oxathiolan-4-yl acetate; linear sulfate esters such as dimethyl sulfate, ethyl methyl sulfate, and diethyl sulfate; 1,2-ethylene sulfate, 1,2-propylene sulfate, 1,3-propylene sulfate, 1,2-butylene sulfate, and 2,4,8,10-tetraoxa-3,9-dithiaspiro[5.5] Cyclic sulfate esters such as undecane-3,3,9,9-tetraoxide; chain sulfite esters such as dimethyl sulfite, ethyl methyl sulfite, and diethyl sulfite; cyclic sulfite esters such as 1,2-ethylene sulfite, 1,2-propylene sulfite, 1,3-propylene sulfite, and 1,2-butylene sulfite; cyclic sulfones such as 1,1-dioxidetetrahydrothiophen-3-ylmethanesulfonate and 1,1-dioxide-2,3-dihydrothiophen-3-ylmethanesulfonate; sulfonic acid esters such as butane-2,3-diyldimethanesulfonate, butane-1,4-diyldimethanesulfonate, and methylenemethane disulfonate; and vinyl sulfones such as divinyl sulfone, 2-bis(vinylsulfonyl)ethane, and bis(2-vinylsulfonylethyl)ether. The sulfur-containing organic compounds may be used alone or in any combination of two or more kinds in any ratio. From the viewpoint of improving low-temperature output characteristics, high-rate charge / discharge characteristics, impedance characteristics, high-temperature storage characteristics, and cycle characteristics, the sulfur-containing organic compound is preferably a chain sulfonate ester, a cyclic sulfonate ester, a cyclic sulfate ester, or a cyclic sulfite ester, more preferably a cyclic sulfonate ester or a cyclic sulfate ester, and even more preferably 1,3-propane sultone, methylenemethane disulfonate, or 1,2-ethylene sulfate.

[0237] [2-6-6. Phosphorus-containing organic compounds] Examples of the phosphorus-containing organic compound that serves as the other compound in this embodiment include trimethyl phosphate, tributyl phosphate, trioctyl phosphate, tripropargyl phosphate, tris(2,2,2-trifluoroethyl)phosphate, ethyl-2-(diethoxyphosphoryl)acetate, 2-propynyl-2-(diethoxyphosphoryl)acetate, methoxypentafluorocyclotriphosphazene, ethoxypentafluorocyclotriphosphazene, phenoxypentafluorocyclotriphosphazene, ethoxyheptafluorocyclotetraphosphazene, etc. One type of phosphorus-containing organic compound may be used alone, or two or more types may be used in any ratio and combination. The phosphorus-containing organic compound is preferably trimethyl phosphate, tributyl phosphate, or trioctyl phosphate, more preferably trimethyl phosphate, from the viewpoint of improving low-temperature output characteristics, high-rate charge / discharge characteristics, impedance characteristics, high-temperature storage characteristics, and cycle characteristics.

[0238] [2-6-7. Silicon-containing compounds] Examples of silicon-containing compounds that can be used as other compounds in this embodiment include boric acid compounds such as tris(trimethylsilyl) borate, tris(trimethoxysilyl) borate, tris(triethylsilyl) borate, and tris(dimethylvinylsilyl) borate; phosphate compounds such as tris(trimethylsilyl) phosphate, tris(triethylsilyl) phosphate, tris(triphenylsilyl) phosphate, tris(trimethoxysilyl) phosphate, and tris(dimethylvinylsilyl) phosphate; tris(trimethylsilyl) phosphite, tris(triethylsilyl) phosphite, tris(triphenylsilyl) phosphite, tris(trimethoxysilyl) phosphite, and tris(dimethylvinylsilyl) phosphate. Examples of suitable silicon-containing compounds include phosphorous compounds such as dimethylvinylsilyl (dimethylvinylsilyl), sulfonic acid compounds such as trimethylsilyl methanesulfonate and trimethylsilyl tetrafluoromethanesulfonate, silane compounds such as tetramethylsilane, trimethylvinylsilane, dimethyldivinylsilane, methyltrivinylsilane, and tetravinylsilane, disilane compounds such as hexamethyldisilane, hexaethyldisilane, 1,1,2,2-tetramethyldisilane, and 1,2-diphenyltetramethyldisilane, and disiloxane compounds such as hexamethyldisiloxane, 1,3-divinyltetramethyldisiloxane, and 1,1,3,3-tetramethyl-1,3-diphenyldisiloxane. The silicon-containing compounds may be used singly or in any combination and ratio. From the viewpoint of improving low-temperature output characteristics, high-rate charge / discharge characteristics, impedance characteristics, high-temperature storage characteristics, and cycle characteristics, the silicon-containing compound is preferably a disilane compound or a disiloxane compound, more preferably a disiloxane compound, further preferably hexamethyldisiloxane or 1,3-divinyltetramethyldisiloxane, and particularly preferably 1,3-divinyltetramethyldisiloxane.

[0239] [2-6-8. Aromatic compounds] Examples of aromatic compounds that can be used as other compounds in this embodiment include cyclohexylbenzene, tert-butylbenzene, tert-amylbenzene, 1-fluoro-4-tert-butylbenzene, biphenyl, o-terphenyl, m-terphenyl, p-terphenyl, fluorobenzene, methyl phenyl carbonate, ethyl phenyl carbonate, diphenyl carbonate, etc. One type of aromatic compound may be used alone, or two or more types may be used in any ratio and combination. From the viewpoint of improving low-temperature output characteristics, high-rate charge / discharge characteristics, impedance characteristics, high-temperature storage characteristics, and cycle characteristics, the aromatic compound is preferably biphenyl, o-terphenyl, m-terphenyl, p-terphenyl, fluorobenzene, cyclohexylbenzene, tert-butylbenzene, or tert-amylbenzene, and more preferably biphenyl, o-terphenyl, fluorobenzene, cyclohexylbenzene, or tert-amylbenzene.

[0240] [2-6-9. Cyano-containing organic compounds] Examples of the cyano group-containing organic compound that can be used as the other compound in this embodiment include monocyano compounds such as acetonitrile, propionitrile, butyronitrile, pentanenitrile, hexanenitrile, decanenitrile, undecanenitrile, dodecanenitrile, cyclohexanecarbonitrile, acrylonitrile, methacrylonitrile, and crotononitrile; dicyano compounds such as succinonitrile, glutaronitrile, adiponitrile, pimelonitrile, suberonitrile, sebaconitrile, methylmalononitrile, ethylmalononitrile, bicyclohexyl-1,1-dicarbonitrile, 1,4-dicyanopentane, and 1,2-dicyanobenzene; and tricyano compounds such as 1,2,3-propanetricarbonitrile, 1,2,3-tris(2-cyanoethoxy)propane, 1,3,6-hexanetricarbonitrile, 1,3,5-cyclohexanetricarbonitrile, and 1,3,5-benzenetricarbonitrile. The cyano group-containing organic compound may be used alone or in any combination and ratio of two or more kinds. From the viewpoint of improving low-temperature output characteristics, high-rate charge / discharge characteristics, impedance characteristics, high-temperature storage characteristics, and cycle characteristics, the cyano group-containing organic compound is preferably a dicyano compound, more preferably succinonitrile or adiponitrile, and even more preferably adiponitrile.

[0241] [2-6-10. Acid anhydride compound] Examples of the acid anhydride compound that can be used as another compound in this embodiment include chain carboxylic acid anhydrides such as acetic anhydride, acrylic anhydride, methacrylic anhydride, cyclohexanecarboxylic anhydride, propynoic anhydride, benzoic anhydride, fluoroacetic anhydride, 4-fluorobenzoic anhydride, and acetic propionic anhydride, as well as succinic anhydride, maleic anhydride, citraconic anhydride, glutaric anhydride, itaconic anhydride, fluorosuccinic anhydride, allylsuccinic anhydride, 1,2-oxathiolan-5-one 2,2-dioxide, and 1,2,6-oxadithiane 2,2,6,6-tetraoxide. One type of acid anhydride compound may be used alone, or two or more types may be used in any ratio and combination. From the viewpoint of improving low-temperature output characteristics, high-rate charge / discharge characteristics, impedance characteristics, high-temperature storage characteristics, and cycle characteristics, the acid anhydride compound is preferably methacrylic anhydride, succinic anhydride, maleic anhydride, or allyl succinic anhydride, and more preferably succinic anhydride or allyl succinic anhydride.

[0242] [2-6-11. Triple bond-containing compounds] Examples of triple bond-containing compounds that can be used as other compounds in this embodiment include 2-propynyl methyl carbonate, 2-propynyl acetate, 2-propynyl formate, 2-propynyl methacrylate, 2-propynyl methanesulfonate, 2-propynyl vinylsulfonate, 2-propynyl 2-(methanesulfonyloxy)propionate, di(2-propynyl)oxalate, 2-butyne-1,4-diyldimethanesulfonate, 2-butyne-1,4-diyldiformate, 1H-imidazole-1-propargyl carboxylate, etc. One type of triple bond-containing compound may be used alone, or two or more types may be used in any ratio and combination. From the viewpoint of improving low-temperature output characteristics, high-rate charge / discharge characteristics, impedance characteristics, high-temperature storage characteristics, and cycle characteristics, the triple bond-containing compound is preferably 2-propynyl methyl carbonate, 2-propynyl methacrylate, 2-propynyl methanesulfonate, 2-propynyl vinylsulfonate, di(2-propynyl)oxalate, or 2-butyne-1,4-diyldimethanesulfonate, more preferably 2-propynyl methanesulfonate, 2-propynyl vinylsulfonate, di(2-propynyl)oxalate, or 2-butyne-1,4-diyldimethanesulfonate.

[0243] [2-7. Method for producing composition (electrolyte solution)] The method for producing the composition according to this embodiment, which is used as an electrolytic solution, includes a step of dissolving the compound (A), the siloxane compound (B), and an electrolyte in a non-aqueous solvent.

[0244] The compound (A) in the production method according to this embodiment is similar to the compound (A) described in [2-1. Compound (A)], and the preferred embodiments are also similar.

[0245] The siloxane compound (B) in the production method according to this embodiment is similar to the siloxane compound (B) in [2-2. Siloxane compound (B)], and the preferred embodiments are also similar.

[0246] The electrolyte in the manufacturing method according to this embodiment is similar to the electrolyte in [2-4. Electrolyte], and preferred embodiments are also similar.

[0247] The non-aqueous solvent in the production method according to this embodiment is similar to the non-aqueous solvent in [2-5. Non-aqueous solvent], and preferred embodiments are also similar.

[0248] The method for dissolving the compound (A), the siloxane compound (B), and the electrolyte in the non-aqueous solvent is not particularly limited. The compound (A), the siloxane compound (B), and the electrolyte may each be sequentially dissolved in a non-aqueous solvent to obtain a composition that will become the electrolyte solution. Alternatively, the compound (A) dissolved in a non-aqueous solvent at a high concentration, the siloxane compound (B) dissolved in a non-aqueous solvent at a high concentration, and the electrolyte dissolved in a non-aqueous solvent at a high concentration may each be sequentially mixed in a non-aqueous solvent to obtain a composition that will become the electrolyte solution.

[0249] [3.Battery] The battery according to this embodiment includes a composition that serves as a positive electrode, a negative electrode, and an electrolyte solution.

[0250] [3-1. Electrolyte] The same explanation as for the electrolyte solution described in [2. Electrolyte Solution] above applies to the electrolyte solution in this embodiment, and the same preferred embodiments also apply. The electrolyte may be used in combination with other electrolytes than those mentioned above, provided that the effects of the present invention are not significantly impaired.

[0251] [3-2. Positive electrode] The positive electrode in this embodiment contains a positive electrode active material on at least a portion of the surface of the current collector.

[0252] [3-2-1. Positive electrode active material] The positive electrode active material in this embodiment is not particularly limited as long as it is capable of electrochemically absorbing and releasing metal ions. Examples of the positive electrode active material include lithium transition metal compounds, sodium transition metal compounds, potassium transition metal compounds, etc. One type of positive electrode active material may be used alone, or two or more types may be used in any ratio and combination. From the viewpoint of increasing the energy density of the battery, the positive electrode active material is preferably a lithium transition metal compound, a sodium transition metal compound, or a potassium transition metal compound, and more preferably a lithium transition metal compound.

[0253] [3-2-1-1. Lithium transition metal compounds] The lithium transition metal compound serving as the positive electrode active material in this embodiment is not particularly limited as long as it has a structure that allows lithium ions to be inserted, deintercalated, and inserted. Examples of lithium transition metal compounds include lithium transition metal sulfides, lithium transition metal phosphate compounds, lithium transition metal silicate compounds, lithium transition metal borate compounds, lithium transition metal composite oxides, etc. The lithium transition metal compounds may be used alone or in any combination and ratio. From the viewpoint of increasing the energy density of the battery, the lithium transition metal compound is preferably a lithium transition metal phosphate compound or a lithium transition metal composite oxide, and more preferably a lithium transition metal composite oxide.

[0254] Examples of the structure of the lithium transition metal composite oxide include a spinel structure, an olivine structure, a layered structure, etc. From the viewpoints of battery capacity and durability, the structure of the lithium transition metal composite oxide is preferably a spinel structure, an olivine structure, or a layered structure, and from the viewpoint of increasing battery capacity, a layered structure is more preferred.

[0255] A lithium transition metal composite oxide having a spinel structure allows lithium ions to diffuse three-dimensionally, and is generally represented by the following composition formula (I).

[0256] [ka]

[0257] (0.8≦a in compositional formula (I) 1 ≦1.5, 1.9≦b 1 ≦2.1, and M 1 is a metal element containing at least one transition metal element and excluding Li.

[0258] M 1 Examples of the metals include Ni, Co, Mn, V, and Al. 1 One kind may be used alone, or two or more kinds may be used in any ratio and combination. M 1 From the viewpoint of improving the cycle performance of the battery, Ni, Co, and Mn are preferred, and Ni and Mn are more preferred.

[0259] Examples of lithium transition metal composite oxides having a spinel structure include LiMn2O4, LiCoMnO4, and LiNi 0.5 Mn 1.5 04, LiCoVO4, etc. The lithium transition metal composite oxides having a spinel structure may be used alone or in any combination and ratio of two or more kinds. Lithium transition metal composite oxides with a spinel structure are used in order to improve the cycle performance of batteries. 0.5 Mn 1.5 O4 is preferred, LiNi 0.5 Mn 1.5 O4 is more preferred.

[0260] A lithium transition metal composite oxide having an olivine structure allows lithium ions to diffuse three-dimensionally, and is generally represented by the following composition formula (II).

[0261] [ka]

[0262] (0.8≦a in compositional formula (II) 2 ≦1.5, 0.9≦b 2 ≦1.1, and M 2 is a metal element containing at least one transition metal element and excluding Li.

[0263] M 2 Examples of the metals include Fe, Ni, Co, Mn, and Al. 2 One kind may be used alone, or two or more kinds may be used in any ratio and combination. M 2 From the viewpoint of improving the cycle performance of the battery, Fe, Ni, Co, and Mn are preferred, and Fe and Mn are more preferred.

[0264] An example of the lithium transition metal composite oxide having an olivine structure is LiFePO4. The lithium transition metal composite oxide having an olivine structure may be used alone or in any combination and ratio. The lithium transition metal composite oxide having an olivine structure is preferably LiFePO4 from the viewpoint of improving the cycle performance of the battery.

[0265] A lithium transition metal composite oxide having a layered structure allows lithium ions to diffuse three-dimensionally, and is generally represented by the following composition formula (III).

[0266] [ka]

[0267] (0.8≦a in compositional formula (III) 3 ≦1.5, 0.5≦b 3 ≦1.1, and M 3 is a metal element containing at least one transition metal element and excluding Li.

[0268] M 3 Examples of the elements include Ni, Co, Mn, Al, Mg, Zr, Fe, Ti, and Er. 3One kind may be used alone, or two or more kinds may be used in any ratio and combination. M 3 From the viewpoint of improving the cycle performance of the battery, Ni, Co, Mn, Al, Mg, and Zr are preferred, and Ni, Co, Mn, and Al are more preferred.

[0269] Examples of lithium transition metal composite oxides having a layered structure include LiCoO2, LiNiO2, and LiNi 0.9 Co 0.05 Mn 0.05 O2, LiNi 0.85 Co 0.1 Al 0.05 O2, LiNi 0.8 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 0.3 Mn 0.2 O 2、 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, solid solutions thereof, etc. The lithium transition metal composite oxides having a layered structure may be used singly or in any combination and ratio of two or more kinds.

[0270] From the viewpoint of increasing battery capacity, the lithium transition metal composite oxide having a layered structure is preferably a lithium transition metal composite oxide represented by the following composition formula (IV), and more preferably a lithium transition metal composite oxide represented by the following composition formula (V).

[0271] [ka]

[0272] (0.8≦a in compositional formula (IV) 4 ≦1.1, 0.3≦b 4 ≦0.98, 0.0≦c 4 ≦0.7, 0.9≦b 4 +c 4 ≦1.1, and M 4 is at least one metal element selected from the group consisting of Co, Mn, Al, Mg, Zr, Fe, Ti, and Er.

[0273] [ka]

[0274] (0.8≦a in compositional formula (V) 5 ≦1.1, 0.3≦b 5 ≦0.98, 0.01≦c 5 ≦0.7, 0.01≦d 5 ≦0.6, 0.9≦b 5 +c 5 +d 5 ≦1.1, and M 5 is at least one metal element selected from the group consisting of Mn, Al, Mg, Zr, Fe, Ti, and Er.

[0275] M in formula (IV) 4 is at least one metal element selected from the group consisting of Co, Mn, Al, Mg, Zr, Fe, Ti, and Er. From the viewpoints of improving the structural stability of the lithium transition metal oxide and suppressing structural deterioration during repeated charge and discharge, Co, Mn, and Al are preferred, and Co and Mn are more preferred.

[0276] b in the composition formula (IV) 4 is 0.3 or more, and from the viewpoint of improving the cycle performance of the battery, is preferably 0.4 or more, more preferably 0.5 or more. 4 is 0.98 or less, and from the viewpoint of battery safety, it is preferably 0.97 or less, and more preferably 0.96 or less.

[0277] The lithium transition metal composite oxide represented by the composition formula (IV) is, for example, LiNi 0.9 Co 0.05 Mn 0.05 O2, LiNi 0.85 Co 0.1 Al 0.05 O2, LiNi 0.8 Co 0.15 Al 0.05 O2, LiNi 0.3 Co 0.3 Mn 0.3 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, LiNi 0.91 Co 0.06 Mn 0.03 O2, LiNi 0.91 Co 0.06 Al 0.03 O2, LiNi 0.9 Co 0.03 Al 0.07 O2, LiNi 0.61 Co 0.2 Mn 0.19 O2, etc. The lithium transition metal composite oxide represented by composition formula (IV) may be used alone or in any combination and ratio of two or more kinds.

[0278] M in the composition formula (V) 5is at least one metal element selected from the group consisting of Mn, Al, Mg, Zr, Fe, Ti, and Er. From the viewpoints of improving the structural stability of the lithium transition metal oxide and suppressing structural deterioration during repeated charge and discharge, Mn and Al are preferred, and Mn is more preferred.

[0279] b in the composition formula (V) 5 is 0.3 or more, and from the viewpoint of increasing the energy density of the battery, is preferably 0.4 or more, more preferably 0.5 or more. 5 is 0.98 or less, and from the viewpoint of battery safety, it is preferably 0.97 or less, and more preferably 0.96 or less.

[0280] d in the composition formula (V) 5 is 0.01 or more, and from the viewpoint of battery safety, is preferably 0.1 or more. 5 is 0.6 or less, and from the viewpoint of increasing the energy density of the battery, it is preferably 0.5 or less.

[0281] Examples of the lithium transition metal composite oxide represented by the composition formula (V) include LiNi 0.9 Co 0.05 Mn 0.05 O2, LiNi 0.85 Co 0.1 Al 0.05 O2, LiNi 0.8 Co 0.15 Al 0.05 O2, LiNi 0.3 Co 0.3 Mn 0.3 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, LiNi 0.91 Co 0.06 Mn 0.03 O2, LiNi0.91 Co 0.06 Al 0.03 O2, LiNi 0.9 Co 0.03 Al 0.07 O2, LiNi 0.61 Co 0.2 Mn 0.19 O2, etc. The lithium transition metal composite oxide represented by composition formula (V) may be used singly or in any combination and ratio of two or more kinds.

[0282] The lithium transition metal composite oxide may further contain elements (foreign elements) other than the elements contained in the above composition formulas (I) to (V).

[0283] [3-2-1-2. 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-attaching substances include oxides such as aluminum oxide, sulfates such as lithium sulfate, carbonates such as lithium carbonate, etc. One type of surface-attaching substance may be used alone, or two or more types may be used in any ratio and combination. From the viewpoint of battery safety, the surface-adhering substance is preferably lithium carbonate. The surface-adhering substance can be attached to the surface of the positive electrode active material by, for example, dissolving it in a solvent or dispersing it in a dispersion medium and impregnating the positive electrode active material with the substance.

[0284] The content of the surface-attached substance relative to the total positive electrode active material is preferably 1 μmol / g or more and 1 mmol / g or less. From the viewpoint of battery safety, the content is preferably 1 μmol / g or more, more preferably 10 μmol / g or more. Furthermore, from the viewpoint of increasing the energy density of the battery, the content is preferably 1 mmol / g or less, more preferably 0.5 mmol / g or less. In this specification, the positive electrode active material also includes a surface-attached substance attached to the surface of the positive electrode active material.

[0285] [3-2-2. Manufacturing method of positive electrode] Examples of the method for producing a positive electrode in this embodiment include a method for obtaining a positive electrode by forming a positive electrode active material layer on a current collector by compression bonding, a method for obtaining a positive electrode by forming a positive electrode active material layer on a current collector by coating, etc. From the viewpoint of simple manufacturing steps and excellent productivity, the method for producing a positive electrode by forming a positive electrode active material layer on a current collector by coating is preferred. The positive electrode active material layer contains a positive electrode active material and a binder, and further contains a conductive material and a thickener, if necessary.

[0286] In the method of forming a positive electrode active material layer on a current collector by compression bonding to obtain a positive electrode, a method is preferred in which a positive electrode active material, a binder, and, if necessary, a conductive material and a thickener are dry-mixed to form a sheet, which is then compressed onto a positive electrode current collector to obtain a positive electrode, from the viewpoint of a simple manufacturing process and excellent productivity.

[0287] In the method of forming a positive electrode active material layer on a current collector by coating to obtain a positive electrode, a method in which a positive electrode active material, a binder, and, if necessary, a conductive material and a thickener further dissolved in a solvent or dispersed in a dispersion medium are coated on a positive electrode current collector and dried to obtain a positive electrode is preferred, from the viewpoint of a simple manufacturing process and excellent productivity.

[0288] [3-2-2-1. Positive electrode active material layer] The content of the positive electrode active material in the positive electrode active material layer is preferably 80 to 99.5% by mass. From the viewpoint of increasing the energy density of the battery, the content is preferably 80% by mass or more, more preferably 90% by mass or more. From the viewpoint of improving the handleability of the positive electrode, the content is preferably 99.5% by mass or less, more preferably 99% by mass or less. When two or more positive electrode active materials are contained, the content refers to the total content of those materials. In this specification, the positive electrode active material is identified and its content is measured by inductively coupled plasma (ICP) optical emission spectroscopy after wet decomposition of the sample. When it is difficult to identify the positive electrode active material or determine its content by inductively coupled plasma (ICP) optical emission spectroscopy alone, other analyses such as X-ray photoelectron spectroscopy (XPS), X-ray fluorescence (XRF), and energy dispersive X-ray spectroscopy (EDS) may be used in combination.

[0289] Examples of binders include fluorine-based resins such as polyvinyl fluoride, polyvinylidene fluoride, and polytetrafluoroethylene; cyano group-containing resins such as polyacrylonitrile and polyvinylidene cyanide; and modified products, derivatives, random copolymers, alternating copolymers, graft copolymers, and block copolymers thereof. One type of binder may be used alone, or two or more types may be used in any ratio and combination. The binder is preferably a fluorine-based resin or a cyano group-containing resin from the viewpoint of weather resistance, chemical resistance, heat resistance, and flame retardancy.

[0290] When a resin is used as the binder, the weight-average molecular weight of the resin is preferably 10,000 to 3,000,000. From the viewpoint of improving the strength of the positive electrode, the weight-average molecular weight is preferably 10,000 or more, more preferably 50,000 or more, and even more preferably 100,000 or more. Furthermore, from the viewpoint of ease of forming the positive electrode, the weight-average molecular weight is preferably 3,000,000 or less, more preferably 950,000 or less, and even more preferably 900,000 or less.

[0291] The content of the binder in the positive electrode active material layer is preferably 0.1 to 20% by mass. From the viewpoint of battery durability, the content is preferably 0.1% by mass or more, more preferably 0.5% by mass or more. Furthermore, from the viewpoint of increasing the energy density of the battery, the content is preferably 20% by mass or less, more preferably 10% by mass or less.

[0292] Examples of conductive materials 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 ratio and combination. The conductive material is preferably carbon black from the viewpoint of increasing conductivity.

[0293] When the positive electrode active material layer contains a conductive material, the content of the conductive material in the positive electrode active material layer is preferably 0.01 to 15% by mass. From the viewpoint of increasing the conductivity, the content is preferably 0.01% by mass or more, more preferably 0.1% by mass or more. Furthermore, from the viewpoint of increasing the energy density of the battery, the content is preferably 15% by mass or less, more preferably 10% by mass or less.

[0294] From the viewpoint of increasing the packing density of the positive electrode active material, the positive electrode active material layer is preferably compacted by a hand press, a roller press, or the like. The density of the positive electrode active material layer is 1.5 to 4.5 g / cm 3 Here, from the viewpoint of increasing the energy density of the battery, the density is preferably 1.5 g / cm 3 More than 2.0 g / cm is preferable. 3 From the viewpoint of impregnation with an electrolyte, the density is more preferably 4.5 g / cm. 3 Preferably less than 4.0 g / cm 3 The following is more preferred:

[0295] The thickness of the positive electrode active material layer is preferably 10 to 500 μm. From the viewpoint of increasing the energy density of the battery, the thickness is preferably 10 μm or more, more preferably 15 μm or more. Furthermore, from the viewpoint of improving the rate characteristics of the battery, the thickness is preferably 500 μm or less, more preferably 300 μm or less. The positive electrode active material layer may be formed on one surface of the current collector, or may be formed on both surfaces of the current collector.

[0296] [3-2-2-2. Current collector] Examples of materials for the current collector include metal materials such as aluminum, stainless steel, nickel plating, titanium, tantalum, etc. From the viewpoint of increasing the energy density of the battery, aluminum is preferred as the material for the current collector.

[0297] Examples of the shape of the current collector include metal foil, metal cylinder, metal coil, metal plate, metal thin film, expanded metal, punched metal, foamed metal, etc. From the viewpoint of improving the handleability of the positive electrode, the shape of the current collector is preferably metal foil or metal thin film. The metal thin film may be formed in a mesh shape.

[0298] When the current collector is in the form of a plate or film, the thickness of the current collector is preferably 1 μm or more and 1 mm or less. Here, from the viewpoint of improving the handleability of the positive electrode, the thickness is preferably 1 μm or more, more preferably 2 μm or more. Furthermore, from the viewpoint of increasing the energy density of the battery, the thickness is preferably 1 mm or less, more preferably 0.5 mm or less.

[0299] [3-2-3. Positive electrode surface coating] The positive electrode may have a substance (surface-adhering substance) having a composition different from that of the positive electrode active material attached to the surface of the positive electrode. The same explanation as for the surface attachment substance of [3-1-1-2. Surface coating] applies to the surface attachment substance of the positive electrode, and the preferred embodiments are also the same. In this specification, the positive electrode also includes a surface-attached substance attached to the surface of the positive electrode.

[0300] [3-3. Negative electrode] The negative electrode in this embodiment contains a negative electrode active material on at least a portion of the surface of the current collector.

[0301] [3-3-1. Negative electrode active material] The negative electrode active material in this embodiment is not particularly limited as long as it is capable of electrochemically absorbing and releasing metal ions. Examples of the negative electrode active material include carbonaceous materials, metal materials, etc. The negative electrode active material may be used alone or in any combination and ratio. The negative electrode active material is preferably a carbonaceous material, a metal material, or a mixture of a carbonaceous material and a metal material from the viewpoints of cycle characteristics, continuous charge characteristics, and safety.

[0302] [3-3-1-1. Carbon-based materials] Examples of the carbonaceous material that can be used as the negative electrode active material in this embodiment include natural graphite such as uncoated natural graphite, amorphous carbon-coated natural graphite, graphite-coated natural graphite, and resin-coated natural graphite; artificial graphite; amorphous carbon; etc. One type of carbonaceous material may be used alone, or two or more types may be used in any ratio and combination. The carbonaceous material is preferably natural graphite from the viewpoint of increasing the battery capacity.

[0303] Examples of natural graphite include scaly natural graphite, scaly natural graphite, and natural graphite obtained by subjecting such graphite to treatment such as spheroidization or densification. One type of natural graphite may be used alone, or two or more types may be used in any ratio and combination. As natural graphite, spherical natural graphite is preferred from the viewpoints of packing properties and charge / discharge rate characteristics.

[0304] [3-3-1-2. Physical properties of carbon-based materials] The d002 value (d value (interlayer distance) of the lattice plane (002 plane)) of a carbon-based material is theoretically 0.3354 nm or more, and from the viewpoint of increasing battery capacity, it is preferably 0.3360 nm or less, and more preferably 0.3357 nm or less. In this specification, the d002 value is measured by the X-ray diffraction method according to the Gakushin method.

[0305] From the viewpoint of increasing battery capacity, the Lc (crystallite size) of the carbon-based material is preferably 0.9 nm or more, more preferably 1.0 nm or more. There is no particular upper limit to the Lc (crystallite size), but it is usually 500 nm or less. In this specification, the Lc value is measured by the X-ray diffraction method according to the Gakushin method.

[0306] The carbonaceous material preferably has an average particle size of 1 to 100 μm. From the viewpoint of increasing battery capacity, the average particle size is preferably 1 μm or more, more preferably 3 μm or more. From the viewpoint of suppressing resistance, the average particle size is preferably 100 μm or less, more preferably 50 μm or less. In this specification, the average particle size of particles of carbon-based materials and the like is the volume-based average particle size (median size), and is measured by a laser diffraction / scattering method.

[0307] The Raman R value of the carbon-based material is preferably 0.01 to 1.5. From the viewpoint of suppressing resistance, the Raman R value is preferably 0.01 or more, more preferably 0.1 or more. Furthermore, from the viewpoint of increasing battery capacity, the Raman R value is preferably 1.5 or less, more preferably 1 or less. In this specification, the Raman R value is measured by argon ion laser Raman spectroscopy.

[0308] The Raman half-width of carbon-based materials is 10 to 100 cm -1 Here, from the viewpoint of suppressing resistance, the Raman half-width is preferably 10 cm -1 More than 20cm is preferable. -1 From the viewpoint of increasing the battery capacity, the Raman half-width is more preferably 100 cm. -1 Less than 80cm is preferable -1 The following is more preferred: In this specification, the Raman half-width is measured by argon ion laser Raman spectroscopy.

[0309] The specific surface area of ​​carbon-based materials is 0.1 to 100 m 2 From the viewpoint of suppressing resistance, the specific surface area is preferably 0.1 m / g. 2 / g or more is preferable, and 0.2m 2 From the viewpoint of increasing the battery capacity, the specific surface area is more preferably 100 m / g or more. 2 / g or less is preferable, and 50m 2 / g or less is more preferable. In this specification, the specific surface area is measured by the BET method.

[0310] [3-3-1-3. Metal materials] The metallic material serving as the negative electrode active material in this embodiment is a material containing a metallic element and / or a semi-metallic element that can be alloyed with an alkali metal. The metallic element constituting the metallic material is a metallic element and / or a semi-metallic element.

[0311] Examples of metal materials include metals such as Fe, Co, Sb, Bi, Pb, Ni, Ag, Si, Sn, Al, Zr, Cr, V, Mn, As, Nb, Mo, Cu, Zn, Ge, In, Ti, and W; and compounds of these metals (metal compounds). One type of metal material may be used alone, or two or more types may be used in any ratio and combination, or an alloy consisting of two or more metals may be used. Examples of metal compounds include metal oxides, metal nitrides, metal carbides, etc. The metal compound may be an oxide, nitride, or carbide of an alloy made of two or more metals.

[0312] From the viewpoints of capacity and cycle life, the metal material is preferably at least one metal selected from the group consisting of Si, Sn, As, Sb, Al, Zn, and W, or a metal compound thereof, and from the viewpoint of increasing capacity, Si and a Si compound are more preferred. In this specification, Si and Si compounds are collectively referred to as Si-based materials.

[0313] Examples of Si compounds include Si oxides, Si nitrides, Si carbides, oxides of Si nitrides, oxides of Si carbides (silicon oxycarbide), etc. One Si compound may be used alone, or two or more Si compounds may be used in any ratio and combination.

[0314] The silicon oxide is, for example, SiO x1 and 0 <x 1 Meets <2. Examples of silicon nitride include Si3N4 and SiN x2 and 0 <x 2 ≦1.3. The Si carbide is, for example, SiCx3 and 0.9≦x 3 ≦1.1. The oxide of Si nitride is, for example, SiN y1 O z1 where 1≦y 1 ≦10, 0 <z 1 ≦1. The oxide of Si carbide is, for example, SiC y2 O z2 where 1≦y 2 ≦10, 0 <z 2 ≦1.

[0315] The Si-based material is preferably an oxide of Si, Si oxide, or Si carbide. Si is preferable because it allows alkali metal salts such as lithium ions to easily enter and exit the material, thereby enabling a high capacity to be achieved. Si oxide is preferred because it has a larger theoretical capacity than graphite. The oxide of Si carbide is preferred because it has a larger theoretical capacity than graphite.

[0316] When used in a battery that does not require high output performance, the metal material is preferably a metal composite oxide from the viewpoint of battery durability. Examples of metal composite oxides include Li 4 / 3 Ti 5 / 3 O4, Li1Ti2O4, Li 4 / 5 Ti 11 / 5 Lithium titanium composite oxides such as O4; Li 4 / 3 Ti 4 / 3 Al 1 / 3 Examples of the metal composite oxide include lithium titanium composite oxides in which a portion of lithium and / or titanium, such as O4, is substituted with another metal (e.g., Al, Ga, Cu, Zn, etc.). One type of metal composite oxide may be used alone, or two or more types may be used in any ratio and combination. As the metal composite oxide, from the viewpoint of high current density charge / discharge characteristics, lithium titanium composite oxide and lithium titanium composite oxide in which part of lithium and / or titanium is substituted with other metals are preferred, and from the viewpoint of reducing output resistance, lithium titanium composite oxide having a spinel structure and lithium titanium composite oxide having a spinel structure in which part of lithium and / or titanium is substituted with other metals are more preferred, and Li 4 / 3 Ti 5 / 3 O4, Li1Ti2O4, Li 4 / 5 Ti 11 / 5 O4, Li 4 / 3 Ti 4 / 3 Al 1 / 3 O4 is more preferred.

[0317] When the metal material is in the form of particles, the average particle size of the metal particles is preferably 0.005 to 10 μm. From the viewpoint of increasing battery capacity, the average particle size is preferably 0.005 μm or more, more preferably 0.1 μm or more. Furthermore, from the viewpoint of suppressing resistance, the average particle size is preferably 10 μm or less, more preferably 5 μm or less.

[0318] [3-3-1-4. Mixture of carbonaceous and metallic materials] The mixture of a carbon-based material and a metal material that serves as the negative electrode active material in this embodiment may be a mixture in which the carbon-based material and the metal material are mixed independently of each other, or may be a composite in which the metal material is present on the surface or inside of the carbon-based material.

[0319] When a mixture of a carbonaceous material and a metallic material is used as the negative electrode active material, the content of the carbonaceous material relative to the total negative electrode active material is preferably 1 to 95% by mass. From the viewpoint of increasing the conductivity of the negative electrode, the content is preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more. Furthermore, from the viewpoint of increasing the energy density of the battery, the content is preferably 95% by mass or less, more preferably 90% by mass or less, and even more preferably 80% by mass or less.

[0320] When a mixture of a carbonaceous material and a metallic material is used as the negative electrode active material, the content of the metallic material in the total negative electrode active material is preferably 5 to 99% by mass. From the viewpoint of increasing the energy density of the battery, the content is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 20% by mass or more. Furthermore, from the viewpoint of suppressing capacity loss during battery operation due to deterioration of the metallic material, the content is preferably 99% by mass or less, more preferably 95% by mass or less, and even more preferably 80% by mass or less.

[0321] [3-3-2. Negative electrode manufacturing method] Examples of the method for producing the negative electrode in this embodiment include a method for forming a negative electrode active material layer on a current collector by compression bonding to obtain a positive electrode, a method for forming a negative electrode active material layer on a current collector by coating to obtain a negative electrode, etc. From the viewpoint of simple production steps and excellent productivity, the method for producing the negative electrode is preferably a method for forming a negative electrode active material layer on a current collector by coating to obtain a negative electrode.

[0322] The negative electrode active material layer contains, in addition to the negative electrode active material and binder, a conductive material, a thickener, and a filler, as needed.

[0323] In the method of forming a negative electrode active material layer on a current collector by compression bonding to obtain a negative electrode, a method is preferred in which a negative electrode active material, a binder, and, if necessary, a conductive material, a thickener, and a filler are dry-mixed to form a sheet, which is then compressed onto a negative electrode current collector to obtain a negative electrode, from the viewpoint of a simple manufacturing process and excellent productivity.

[0324] In the method of forming a negative electrode active material layer on a current collector by coating to obtain a negative electrode, a method of coating a slurry, in which, in addition to the negative electrode active material and binder, if necessary, a conductive material, a thickener, and a filler are further dispersed in a dispersion medium, on the negative electrode current collector and drying the slurry to obtain a negative electrode is preferred, from the viewpoint of simple manufacturing steps and excellent productivity.

[0325] [3-3-2-1. Negative electrode active material layer] The content of the negative electrode active material in the negative electrode active material layer is preferably 80 to 99.5% by mass. From the viewpoint of increasing the energy density of the battery, the content is preferably 80% by mass or more, more preferably 90% by mass or more. From the viewpoint of improving the handleability of the negative electrode, the content is preferably 99.5% by mass or less, more preferably 99% by mass or less. When two or more negative electrode active materials are contained, the content refers to the total content of those materials. In this specification, the identification of the negative electrode active material and the content of the negative electrode active material are measured by alkali fusion of a sample followed by high-frequency inductively coupled plasma (ICP) emission spectrometry.

[0326] Examples of binders include rubbery polymers such as styrene-butadiene rubber (SBR), isoprene rubber, butadiene rubber, fluororubber, acrylonitrile-butadiene rubber (NBR), and ethylene-propylene rubber; and fluorine-based polymers such as polyvinylidene fluoride, polytetrafluoroethylene, fluorinated polyvinylidene fluoride, and tetrafluoroethylene-ethylene copolymer. One type of binder may be used alone, or two or more types may be used in any ratio and combination. From the viewpoint of battery durability, the binder is preferably styrene-butadiene rubber.

[0327] The content of the binder in the negative electrode active material layer is preferably 0.1 to 20% by mass. From the viewpoint of battery durability, the content is preferably 0.1% by mass or more, more preferably 0.5% by mass or more. Furthermore, from the viewpoint of increasing the energy density of the battery, the content is preferably 20% by mass or less, more preferably 10% by mass or less.

[0328] When a rubbery polymer is used as the main component of the binder, the content of the binder in the negative electrode active material layer is preferably 0.1 to 5% by mass. From the viewpoint of battery durability, the content is preferably 0.1% by mass or more, more preferably 0.5% by mass or more. Furthermore, from the viewpoint of increasing the energy density of the battery, the content is preferably 5% by mass or less, more preferably 2% by mass or less.

[0329] When a fluorine-based polymer is used as the main component of the binder, the content of the binder in the negative electrode active material layer is preferably 1 to 15% by mass. From the viewpoint of battery durability, the content is preferably 1% by mass or more, more preferably 2% by mass or more. Furthermore, from the viewpoint of increasing the energy density of the battery, the content is preferably 15% by mass or less, more preferably 10% by mass or less.

[0330] Examples of conductive materials include 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 ratio and combination. The conductive material is preferably carbon black from the viewpoint of increasing conductivity.

[0331] When the negative electrode active material layer contains a conductive material, the content of the conductive material in the negative electrode active material layer is preferably 0.01 to 15% by mass. From the viewpoint of increasing conductivity, the content is preferably 0.01% by mass or more, more preferably 0.1% by mass or more. Furthermore, from the viewpoint of increasing the energy density of the battery, the content is preferably 15% by mass or less, more preferably 10% by mass or less.

[0332] Examples of thickeners include carboxymethyl cellulose, methyl cellulose, hydroxymethyl cellulose, ethyl cellulose, polyvinyl alcohol, salts thereof, etc. One type of thickener may be used alone, or two or more types may be used in any ratio and combination. From the viewpoint of battery durability, the thickener is preferably carboxymethyl cellulose.

[0333] When the negative electrode active material layer contains a thickener, the content of the thickener in the negative electrode active material layer is preferably 0.5 to 5% by mass. From the viewpoint of battery durability, the content is preferably 0.5% by mass or more, more preferably 1% by mass or more. Furthermore, from the viewpoint of increasing the energy density of the battery, the content is preferably 5% by mass or less, more preferably 2% by mass or less.

[0334] From the viewpoint of increasing the packing density of the negative electrode active material, the negative electrode active material layer is preferably compacted by a hand press, a roller press, or the like. The density of the negative electrode active material layer is 1.0 to 2.2 g / cm 3 Here, from the viewpoint of increasing the energy density of the battery, the density is preferably 1.0 g / cm 3 More than 1.5g / cm is preferable. 3 From the viewpoint of impregnation with an electrolyte, the density is more preferably 2.2 g / cm. 3 Preferably less than 2.0 g / cm 3 The following is more preferred:

[0335] The thickness of the negative electrode active material layer is preferably 10 to 500 μm. From the viewpoint of increasing the energy density of the battery, the thickness is preferably 10 μm or more, more preferably 15 μm or more. Furthermore, from the viewpoint of improving the rate characteristics of the battery, the thickness is preferably 500 μm or less, more preferably 300 μm or less. The negative electrode active material layer may be formed on one surface of the current collector, or may be formed on both surfaces of the current collector.

[0336] [3-3-2-2. Current collector] Examples of materials for the current collector include metal materials such as aluminum, copper, nickel, stainless steel, nickel-plated steel, etc. Copper is preferred as the current collector material because it does not alloy with alkali metals and is inexpensive.

[0337] Examples of the shape of the current collector include metal foil, metal cylinder, metal coil, metal plate, metal thin film, expanded metal, punched metal, foamed metal, etc. From the viewpoint of improving the handleability of the negative electrode, the shape of the current collector is preferably metal foil or metal thin film. The metal thin film may be formed in a mesh shape.

[0338] When the current collector is in the form of a plate or film, the thickness of the current collector is preferably 1 μm or more and 1 mm or less. Here, from the viewpoint of improving the handleability of the negative electrode, the thickness is preferably 1 μm or more, more preferably 2 μm or more. Furthermore, from the viewpoint of increasing the energy density of the battery, the thickness is preferably 1 mm or less, more preferably 0.5 mm or less.

[0339] [3-3-3. Surface coating of negative electrode] The negative electrode may have a substance (surface-adhering substance) having a composition different from that of the negative electrode active material attached to the surface of the negative electrode. The same explanation as for the surface attachment material on the surface of the positive electrode in [3-2-3. Surface coating of positive electrode] applies to the surface attachment material on the surface of the negative electrode, and the preferred embodiments are also the same. In this specification, the negative electrode also includes a surface-attached substance attached to the surface of the negative electrode.

[0340] [3-4. Separator] In the battery according to this embodiment, it is preferable to interpose a separator between the positive electrode and the negative electrode in order to prevent short circuits. The separator is preferably used by impregnating it with an electrolytic solution.

[0341] Known materials can be used for the separator as long as they do not significantly impair the effects of the present invention. The separator may have any known shape as long as it does not significantly impair the effects of the present invention.

[0342] [3-5.Battery design] [3-5-1. Electrode group] The electrode group in this embodiment may have a laminated structure in which a positive electrode and a negative electrode are laminated with a separator interposed therebetween, or may have a wound structure in which a positive electrode and a negative electrode are spirally wound with a separator interposed therebetween.

[0343] The electrode group occupancy rate, i.e., the volume ratio of the electrode group to the internal volume of the battery, is preferably 40 to 90%. From the viewpoint of increasing the energy density of the battery, the electrode group occupancy rate is preferably 40% or more, more preferably 50% or more. Furthermore, from the viewpoint of impregnation with the electrolyte, the electrode group occupancy rate is preferably 90% or less, more preferably 80% or less.

[0344] [3-5-2. Current collection structure] When the electrode group in this embodiment has a laminated structure, a structure formed by bundling the metal core portions of each electrode layer and welding them to a terminal, or a structure in which multiple terminals are provided within the electrode to reduce resistance, is preferably used. Furthermore, when the electrode group has a wound structure, a structure is preferably used in which each electrode is provided with a plurality of lead structures and bundled together at a terminal to reduce resistance.

[0345] [3-5-3.Protection elements] Examples of protective elements include a PTC (Positive Temperature Coefficient) element whose resistance increases with heat generation due to excessive current, a thermal fuse, a thermistor, a current cutoff valve that cuts off current flowing in a circuit due to a sudden increase in the internal pressure or temperature of the battery during abnormal heat generation, etc. One type of protective element may be used alone, or two or more types may be used in any ratio and combination. From the viewpoint of battery safety, it is preferable that the protective element be one that will not operate under normal high current use, but it is more preferable to design the battery so that abnormal heat generation or thermal runaway does not occur even without a protective element.

[0346] [3-5-4. Exterior body] The battery according to this embodiment is generally configured by housing a positive electrode, a negative electrode, a separator, and an electrolyte solution in an exterior body.

[0347] Examples of materials for the exterior body include metals such as iron, aluminum, and aluminum alloys; laminate films, etc. From the viewpoints of weight reduction and cost, metals and laminate films are preferred as the material for the exterior body, and from the viewpoint of pressure resistance for operating the current cutoff valve, iron is more preferred.

[0348] When a metal is used as the material of the exterior body, the structure of the exterior body may be a sealed, airtight structure in which metal pieces are welded together by laser welding, resistance welding, or ultrasonic welding, or a crimped structure in which metal is used via a resin gasket.

[0349] Examples of the shape of the exterior body include cylindrical, rectangular, laminate, coin, large, etc. From the viewpoint of increasing the energy density of the battery, the exterior body is preferably cylindrical, rectangular, or laminate.

[0350] [3-6. Battery manufacturing method] The method for manufacturing a battery according to this embodiment includes the steps of housing the positive electrode and negative electrode in an exterior body, and injecting the composition according to this embodiment, which is an electrolyte solution, into the exterior body.

[0351] The same explanation as for the electrolyte solution described above in [3-1. Electrolyte Solution] applies to the electrolyte solution, and the preferred embodiments are also the same. The electrolyte may be used in combination with other electrolytes than those mentioned above, provided that the effects of the present invention are not significantly impaired.

[0352] The same explanation as for the positive electrode of the battery described above in [3-2. Positive electrode] applies to the positive electrode of the battery in the manufacturing method of the battery, and the preferred embodiments are also the same.

[0353] The negative electrode in the battery manufacturing method is similar to the negative electrode of the battery described above in [3-3. Negative Electrode], and the preferred embodiments are also similar.

[0354] For the exterior body of the battery manufacturing method, the same explanation as for the exterior body of the battery described above in [3-5-4. Exterior Body] applies, and the same preferred embodiments also apply.

[0355] Either the step of housing the positive electrode and the negative electrode in the outer casing or the step of injecting the composition serving as the electrolyte solution into the outer casing may be carried out first, but from the viewpoint of impregnating the outer casing with the electrolyte solution, it is preferable to carry out the step of injecting the electrolyte solution into the outer casing after the step of housing the positive electrode and the negative electrode in the outer casing.

[0356] In the step of housing the positive electrode and negative electrode in an exterior body, it is preferable to house a separator in the exterior body together with the positive electrode and negative electrode, from the viewpoint of simplifying the manufacturing process and improving productivity.

[0357] [3-7.Application] From the viewpoint of being repeatedly usable for a variety of applications, the battery according to this embodiment is preferably a non-aqueous electrolyte secondary battery, more preferably an alkali ion secondary battery, and even more preferably a lithium ion secondary battery.

[0358] The battery according to this embodiment can be used for various known applications. Specific examples of uses include notebook computers, pen-input computers, mobile computers, e-book players, mobile phones, mobile fax machines, mobile copiers, mobile printers, portable audio players, small video cameras, headphone stereos, video movies, LCD televisions, handheld vacuum cleaners, portable CDs, minidiscs, walkie-talkies, electronic organizers, calculators, memory cards, portable tape recorders, radios, backup power supplies, motors, automobiles, motorcycles, mopeds, bicycles, lighting equipment, toys, game equipment, clocks, power tools, strobe lights, cameras, home backup power supplies, business backup power supplies, load-leveling power supplies, and natural energy storage power supplies.

[0359] In particular, the battery according to this embodiment has an excellent effect of suppressing gas generation in an overdischarge state, and from the viewpoint of safe use, it can be suitably used in vehicles such as automobiles, motorcycles, mopeds, and bicycles, and is particularly suitably used in automobiles. That is, the present invention also relates to a vehicle including the battery. [Example]

[0360] 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.

[0361] [Raw materials] In the following examples and comparative examples, the following materials were used as raw materials for producing the electrolyte solutions.

[0362] Compound (A-1): Compound represented by the following formula (manufactured by Tokyo Chemical Industry Co., Ltd.) (corresponding to compound (A1))

[0363] [ka]

[0364] Compound (B-1): "BYK-333" (product name, manufactured by BYK-Chemie, polyether-modified polydimethylsiloxane with 8 or more silicon atoms, siloxane compound (B1)) Compound (B-2): "SH 200 C Fluid 1000 CS" (product name, manufactured by DuPont Toray Specialty Materials Co., Ltd., dimethyl silicone with 8 or more silicon atoms, siloxane compound (B2))

[0365] Compound (B'-1): A compound represented by the following general formula (manufactured by Tokyo Chemical Industry Co., Ltd.) [ka]

[0366] [Cathode manufacturing] The positive electrode active material is a lithium transition metal composite oxide (LiNi 0.5 Co 0.3 Mn 0.2 90 parts by mass of 02), 3 parts by mass of polyvinylidene fluoride (weight average molecular weight approximately 280,000) as a binder, and 7 parts by mass of acetylene black as a conductive material were mixed in N-methylpyrrolidone using a disperser to obtain a slurry. The obtained slurry was applied to both sides of a current collector (aluminum foil with a thickness of 21 μm), dried, and then the density was 3.3 g / cm. 3 The positive electrode was pressed so that the positive electrode active material layer was formed.

[0367] [Manufacturing of negative electrodes] 98 parts by mass of natural graphite powder as the negative electrode active material, 1 part by mass (solid content equivalent) of an aqueous dispersion of styrene-butadiene rubber (styrene-butadiene rubber concentration 50% by mass) as a binder, and 1 part by mass (solid content equivalent) of an aqueous dispersion of carboxymethylcellulose sodium (carboxymethylcellulose sodium concentration 1% by mass) as a thickener were mixed using a disperser to obtain a slurry. The obtained slurry was applied to one side of a current collector (copper foil with a thickness of 12 μm) and dried to obtain a slurry with a density of 1.6 g / cm. 3 The negative electrode was pressed so that the negative electrode active material layer was formed.

[0368] [Electrolyte production] The compositions obtained in Examples 1 and 2 and Comparative Examples 1 to 5 described below were used as they were as the electrolyte solutions.

[0369] [Battery manufacturing] The resulting positive electrode and negative electrode were stacked with a polypropylene separator between them to obtain an electrode group. The resulting electrode group was inserted into a laminate film bag made of aluminum (40 μm thick) coated on both sides with a resin layer so that the positive and negative electrode terminals protruded. The resulting electrolyte was then injected into the bag and vacuum-sealed to produce a pouch-type battery.

[0370] [Charge / discharge before test] The resulting battery was sandwiched between glass plates to enhance adhesion between the electrodes, and charged at a constant current of 0.05 C for 4 hours at 25°C, and then discharged to 2.5 V at a constant current of 0.2 C. 1 C represents the current value required to discharge the battery's reference capacity in 1 hour, 0.5 C represents half that current value, and 0.2 C represents one-fifth of that current value. Next, at 25°C, the battery was charged to 4.1 V at a constant current of 0.1 C, discharged to 2.5 V at a constant current of 0.2 C, constant current-constant voltage charged to 4.1 V at 0.2 C (0.05 C cutoff), and then discharged to 2.5 V at a constant current of 0.2 C. It was then charged to 4.2 V at a constant current of 0.2 C (0.05 C cutoff), and then discharged to 2.5 V at a constant current of 0.2 C. It was then charged to 4.2 V at a constant current-constant voltage of 0.2 C (0.05 C cutoff), and then discharged to 2.5 V at a constant current of 1.0 C. It was then charged to 2.5 V at a constant current of 1.3 C (0.05 C cutoff), completing the pre-test charge-discharge cycle.

[0371] [Measurement of gas generation rate in over-discharge state] Before the test, the glass plates were removed from the batteries after charging and discharging, and the battery volume was measured using Archimedes' principle.The batteries were then sandwiched between the glass plates again and stored at 60°C for one week.Then, the glass plates were removed from the batteries, and the battery volume was measured using Archimedes' principle. The change in the volume of the battery before and after storage was taken as the amount of gas generated in an overdischarged state, and was expressed as a relative value, with the amount of gas generated in an overdischarged state when the composition of Comparative Example 1 was used being taken as 100. The results are shown in Table 1.

[0372] [Example 1] Under a dry argon atmosphere, LiPF was dissolved in a mixed solvent of 30% by volume of ethylene carbonate, 40% by volume of ethyl methyl carbonate, and 30% by volume of dimethyl carbonate to a concentration of 1.0 mol / L, and compound (A-1) and compound (B-1) were dissolved in the resulting solution to a content of 0.1% by mass and a content of 0.1% by mass, respectively, to obtain a composition.

[0373] [Example 2] Compositions were obtained in the same manner as in Example 1, except that the type of siloxane compound (B) was changed as shown in Table 1.

[0374] [Comparative Examples 1 to 5] Compositions were obtained in the same manner as in Example 1, except that the types and contents of the compounds were changed as shown in Table 1. In Table 1, "-" means that no additive was added.

[0375] [Table 1]

[0376] As can be seen from Table 1, the compositions of Examples 1 and 2 according to this embodiment were excellent in the effect of suppressing gas generation in an overdischarge state when used as an electrolyte solution in a battery. On the other hand, the compositions of Comparative Examples 2 and 3, which did not contain compound (A), and the composition of Comparative Example 4, which did not contain siloxane compound (B), did not show any effect of suppressing gas generation under overdischarge conditions when used in a battery electrolyte, indicating that the addition of compound (A) or siloxane compound (B) alone does not produce the above-mentioned effect. Furthermore, the composition of Comparative Example 5, which contained compound (B'-1), which is different from siloxane compound (B), did not show any effect of suppressing gas generation under overdischarge conditions when used in a battery electrolyte, even when used together with compound (A). [Industrial Applicability]

[0377] When the composition according to the present embodiment is used as an electrolyte or an additive for an electrolyte, a battery using the electrolyte can be used in various known applications. Specific examples of applications include notebook computers, pen-input personal computers, mobile personal computers, electronic book players, mobile phones, mobile fax machines, mobile copy machines, mobile printers, mobile audio players, small video cameras, headphone stereos, video movie cameras, LCD televisions, handheld vacuum cleaners, portable CD players, minidiscs, transceivers, electronic organizers, calculators, memory cards, portable tape recorders, radios, backup power supplies, motors, automobiles, motorcycles, mopeds, bicycles, lighting equipment, toys, game machines, clocks, power tools, flash devices, cameras, home backup power supplies, business backup power supplies, load-leveling power supplies, and natural energy storage power supplies. The battery has an excellent effect of suppressing gas generation in an overdischarge state and can be used safely, and therefore can be suitably used in vehicles such as automobiles, motorcycles, mopeds, and bicycles, and is particularly suitably used in automobiles.

Claims

1. A composition comprising a compound (A) containing at least one of a compound (A1) represented by the following general formula (1) and a compound (A2) represented by the following general formula (2), and a siloxane compound (B) having 8 or more silicon atoms: 【Chemistry 1】 (In general formula (1), R １０１ and R １０２ are each independently a hydrogen atom, a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, or —SiR １０３ R １０４ R １０５ is a silyl group represented by R １０３ ~R １０５ are each independently a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, or an alkoxy group having 1 to 12 carbon atoms which may have a substituent; Y is a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, an alkoxy group having 1 to 12 carbon atoms which may have a substituent; -NR １０６ -SiR １０７ R １０８ R １０９ or a group represented by —NR １１０ -R １１１ is a group represented by R １０６ , R １１０ and R １１１ are each independently a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, and R １０７ ~R １０９ are each independently a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, or an alkoxy group having 1 to 12 carbon atoms which may have a substituent. １０１ or R １０２ may be bonded to form a ring.) 【Chemistry 2】 (In general formula (2), R ２０１ ~R ２０３ are each independently a hydrogen atom, an optionally substituted alkyl group having 1 to 10 carbon atoms, an optionally substituted aryl group having 6 to 18 carbon atoms, or an optionally substituted aralkyl group having 7 to 18 carbon atoms, and Z is an optionally substituted alkenyl group or alkynyl group having 2 to 10 carbon atoms.

2. The compound (A1) may be a compound represented by the general formula (1) R １０１ and R １０２ At least one of the groups is —SiR １０３ R １０４ R １０５ The composition according to claim 1 , comprising a compound having a silyl group represented by the formula:

3. The composition according to claim 1, wherein the compound (A2) comprises a compound in which Z in the general formula (2) is at least one selected from the group consisting of a vinyl group, an allyl group, and a methallyl group.

4. The composition according to claim 1, wherein the siloxane compound (B) comprises at least one of a siloxane compound (B1) represented by the following general formula (3) and a siloxane compound (B2) represented by the following general formula (4): 【Transformation 3】 (In general formula (3), R ３０１ is an alkyl group having 1 to 3 carbon atoms or a phenyl group, and R ３０２ is an alkyl group having 1 to 3 carbon atoms, a phenyl group, a polyether group, a carboxylic acid ester group, a sulfonic acid ester group, a phosphite ester group, or a phosphate ester group, and R ３０３ ~R ３０８ are each independently an alkyl group having 1 to 3 carbon atoms or a phenyl group, and n ３ is an integer of 6 or more and 100,000 or less, and n ３ There are R ３０１ and R ３０２ may be the same or different.) 【Chemistry 4】 (In general formula (4), R ４０１ is an alkyl group having 1 to 3 carbon atoms or a phenyl group, and R ４０２ is an alkyl group having 1 to 3 carbon atoms, a phenyl group, a polyether group, a carboxylate group, a sulfonate group, a phosphite group, or a phosphate group, and n ４ is an integer of 8 or more and 100,000 or less, and n ４ There are R ４０１ and R ４０２ may be the same or different.)

5. The composition according to any one of claims 1 to 4, further comprising an electrolyte and a non-aqueous solvent, and used as an electrolytic solution.

6. The composition according to claim 5 , wherein the total content of the compound (A) in the composition is 0.0001% by mass or more and 0.2% by mass or less.

7. The composition according to claim 5 , wherein the total content of the siloxane compounds (B) in the composition is 0.0001% by mass or more and 0.2% by mass or less.

8. 6. A method for producing the composition of claim 5, comprising: A method for producing a composition, comprising: dissolving the compound (A), the siloxane compound (B), and the electrolyte in the non-aqueous solvent.

9. A battery comprising a positive electrode, a negative electrode and the composition of claim 5.

10. A method for manufacturing a battery, comprising the steps of: housing a positive electrode and a negative electrode in an exterior body; and injecting the composition according to claim 5 into the exterior body.

11. A vehicle comprising the battery of claim 9.

Images