Non-aqueous electrolyte and non-aqueous electrolyte secondary battery

Abstract

A non-aqueous electrolyte according to the present disclosure contains a first component. The non-aqueous electrolyte further contains at least two types of second components, or further contains a second component and a third component. The first component is at least one selected from the group consisting of compounds represented by formula (I-1) below and compounds represented by formula (I-2) below. The second component represents a specific compound. The third component represents a specific compound.

Description

Non-aqueous electrolyte and non-aqueous electrolyte secondary battery

[0001] This disclosure relates to non-aqueous electrolytes and non-aqueous electrolyte secondary batteries.

[0002] The performance of energy storage devices (such as small, lightweight, and high-output lithium-ion secondary batteries) has been improving in recent years. With the advancement of energy storage devices, they are being used not only in small electrical products but also in large products (such as automobiles). Lithium-ion secondary batteries require various characteristics (e.g., output characteristics, charge / discharge characteristics, and gas generation) to meet specific requirements. For example, minimizing the output degradation of a lithium-ion secondary battery when stored for long periods in high-temperature environments is a very important evaluation criterion.

[0003] Patent Document 1 specifically discloses a non-aqueous electrolyte. This non-aqueous electrolyte includes lithium trifluoromethanesulfonate (TFMSLi), lithium difluorophosphate (LiDFP), and lithium bis(oxalato)borate (LiBOB). Patent Document 1 discloses that a lithium-ion secondary battery equipped with this non-aqueous electrolyte exhibits a reduced resistance value at -10°C after being stored at 60°C for 5 days.

[0004] Patent Document 1: International Publication No. 2018 / 181369

[0005] In this disclosure, lithium-ion secondary batteries containing a non-aqueous electrolyte are referred to as "non-aqueous electrolyte secondary batteries."

[0006] One object of this disclosure is to provide a non-aqueous electrolyte and a non-aqueous electrolyte secondary battery that can suppress the increase in resistance after high-temperature storage of the non-aqueous electrolyte secondary battery.

[0007] As a result of diligent research to solve the aforementioned problems, the Disclosers have found that by incorporating a specific first component and using a non-aqueous electrolyte that satisfies specific conditions, it is possible to suppress the increase in resistance of a non-aqueous electrolyte secondary battery after high-temperature storage, and have completed this disclosure.

[0008] In other words, one aspect of the present disclosure is as follows: <1> A non-aqueous electrolyte comprising a first component, wherein the first component represents at least one compound selected from the group consisting of a compound represented by the following formula (I-1) and a compound represented by the following formula (I-2), and satisfying the following condition (a) or the following condition (b). Condition (a): The non-aqueous electrolyte further comprises a second component, wherein the second component comprises at least two compounds selected from the group consisting of the compound represented by formula (II), the compound represented by formula (III), the compound represented by formula (IV), and the compound represented by formula (V). Condition (b): The non-aqueous electrolyte further comprises a second component and a third component, wherein the second component comprises at least one compound selected from the group consisting of the compound represented by formula (II), the compound represented by formula (III), the compound represented by formula (IV), and the compound represented by formula (V), and the third component comprises at least one compound selected from the group consisting of the compound represented by formula (VI), the compound represented by formula (VII), the compound represented by formula (VIII-1), the compound represented by formula (VIII-2), the compound represented by formula (IX), the compound represented by formula (X), the compound represented by formula (XI), and the compound represented by formula (XII).

[0009]

[0010] (In formula (I-1), R １１ and R １２ These can be independently substituted with a halogen group, an oxa group (-O-), a carbonyl group (>C=O), and a sulfonyl group (>S(=O)). ２ This represents a divalent hydrocarbon group having 1 to 6 carbon atoms, which may contain at least one functional group selected from the group consisting of ). In formula (I-2), R １１ The substituents are a halogen group, an oxa group (-O-), a carbonyl group (>C=O), and a sulfonyl group (>S(=O)). ２ Represents a divalent hydrocarbon group having 1 to 6 carbon atoms, which may contain at least one functional group selected from the group consisting of ). １３each independently represents a hydrocarbon group having 1 to 12 carbon atoms which may optionally contain at least one functional group selected from the group consisting of a halogeno group, a cyano group (-CN), an oxa group (-O-), a carbonyl group (>C=O), and a sulfonyl group (>S(=O) ２ )).

[0011]

[0012] (In formula (II), R ２１ represents a fluorinated hydrocarbon group having 1 to 12 carbon atoms which may optionally contain an oxa group (-O-) as a substituent, or a hydrocarbon group having 1 to 12 carbon atoms containing a fluoro group (-F) as a substituent. M ＋ represents an alkali metal ion, an ammonium ion, an imidazolium ion, a pyridinium ion, a pyrrolidinium ion, a piperidinium ion, or a phosphonium ion. In formula (III), R ３１ represents a methylene group (-CH ２ -), an ethylene group (-CH ２ CH ２ -), or an n-propylene group (-CH ２ CH ２ CH ２ -). In formula (IV), R ４１ represents a methylene group (-CH ２ -), an ethylene group (-CH ２ CH ２ -), or an n-propylene group (-CH ２ CH ２ CH ２ -). R ４２ each independently represents a hydrocarbon group having 1 to 12 carbon atoms which may optionally contain at least one functional group selected from the group consisting of a halogeno group and an oxa group (-O-) as a substituent. When R ４１ is a methylene group (-CH ２ -), h represents 1 or 2. When R ４１ is an ethylene group (-CH ２ CH ２ -), h represents an integer of 1 to 4. When R ４１ is an n-propylene group (-CH ２ CH ２ CH２ When h is -, h represents an integer from 1 to 6. In equation (V), R ５１ is a methylene group (-CH ２ -), ethylene group (-CH ２ CH ２ -), or n-propylene group (-CH ２ CH ２ CH ２ Represents (-). ５２ Each of these independently represents the group represented by formula (v-1), the group represented by formula (v-2), the group represented by formula (v-3), the group represented by formula (v-4), the group represented by formula (v-5), the group represented by formula (v-6), or the group represented by formula (v-7). ５１ is a methylene group (-CH ２ When i is -, it represents either 1 or 2. ５１ is an ethylene group (-CH ２ CH ２ When i is -, it represents an integer from 1 to 4. ５１ is an n-propylene group (-CH ２ CH ２ CH ２ When i is -, i represents an integer from 1 to 6. In equation (v-3), R ５３ This represents a hydrocarbon group having 1 to 12 carbon atoms, which may contain at least one functional group selected from the group consisting of a halogen group and an oxa group (-O-) as a substituent.

[0013]

[0014] (In equation (VI), the double line, which is both solid and dotted, represents a single bond (-) or a double bond (=). ６１ represents a halogeno group, a fluorine carbide group having 1 to 12 carbon atoms which may contain an oxa group (-O-) as a substituent, or a hydrocarbon group having 1 to 12 carbon atoms which may contain at least one functional group selected from the group consisting of a fluoro group (-F) and an oxa group (-O-) as a substituent. j represents an integer from 0 to 4. In formula (VII), Q represents a boron atom (B) or a phosphorus atom (P). R ７１Each independently represents a divalent hydrocarbon group having 1 to 6 carbon atoms, which may contain a single bond (-) or at least one functional group selected from the group consisting of a halogen group and an oxa group (-O-) as a substituent. Each independently represents a halogen group. When Q is a boron atom (B), a represents 1 or 2, when a is 1, b represents 2, and when a is 2, b represents 0. When Q is a phosphorus atom (P), a represents an integer from 1 to 3, when a is 1, b represents 4, when a is 2, b represents 2, and when a is 3, b represents 0. c represents an integer from 1 to 3. M ＋ M represents an alkali metal ion, ammonium ion, imidazolium ion, pyridinium ion, pyrrolidinium ion, piperidinium ion, or phosphonium ion. In formula (VIII-1), M ＋ represents an alkali metal ion, ammonium ion, imidazolium ion, pyridinium ion, pyrrolidinium ion, piperidinium ion, or phosphonium ion. In formula (VIII-2), two M ＋ Each of these independently represents an alkali metal ion, an ammonium ion, an imidazolium ion, a pyridinium ion, a pyrrolidinium ion, a piperidinium ion, or a phosphonium ion. In formula (IX), M ＋ R represents an alkali metal ion, ammonium ion, imidazolium ion, pyridinium ion, pyrrolidinium ion, piperidinium ion, or phosphonium ion. In formula (X), two R １０１ Each of these independently represents a fluorine carbide group having 1 to 12 carbon atoms, which may contain a fluoro group (-F), an oxa group (-O-) as a substituent, or a hydrocarbon group having 1 to 12 carbon atoms, which contains a fluoro group (-F) as a substituent. ＋ R represents an alkali metal ion, ammonium ion, imidazolium ion, pyridinium ion, pyrrolidinium ion, piperidinium ion, or phosphonium ion. In formula (XI), R １１１Each independently represents a halogeno group, a 1-12 carbon atom fluorine carbide group which may contain an oxa group (-O-) as a substituent, or a 1-12 carbon atom hydrocarbon group which may contain at least one functional group selected from the group consisting of a fluoro group (-F) and an oxa group (-O-) as a substituent. m represents an integer from 0 to 2. In formula (XII), the two R １２１ Each of these independently represents a hydrocarbon group having 1 to 12 carbon atoms or a trialkylsilyl group having 3 to 18 carbon atoms.) <2> The non-aqueous electrolyte according to claim <1>, wherein the total content of the first component is 0.001% by mass to 5.0% by mass with respect to the total amount of the non-aqueous electrolyte. <3> The non-aqueous electrolyte according to <1> or <2>, satisfying condition (a), wherein the total content of the second component is 0.001% by mass to 5.0% by mass with respect to the total amount of the non-aqueous electrolyte. <4> The non-aqueous electrolyte according to <1> or <2>, satisfying condition (b), wherein the total content of the second component is 0.001% by mass to 5.0% by mass with respect to the total amount of the non-aqueous electrolyte. <5> The non-aqueous electrolyte according to <1>, <2>, or <4>, satisfying condition (b), wherein the total content of the third component is 0.001% by mass to 20.0% by mass with respect to the total amount of the non-aqueous electrolyte. <6> The non-aqueous electrolyte according to any one of <1> to <5>, wherein the compound represented by formula (V) is at least one selected from the group consisting of the compound represented by the following formula (V-1), the compound represented by the following formula (V-2), the compound represented by the following formula (V-3), the compound represented by the following formula (V-4), the compound represented by the following formula (V-5), the compound represented by the following formula (V-6), and the compound represented by the following formula (V-7).

[0015]

[0016] <7> A non-aqueous electrolyte comprising one or more compounds selected from the group consisting of compounds represented by the following formula (I-1) and compounds represented by the following formula (I-2), and one or more compounds selected from the group consisting of compounds represented by the following formula (IV).

[0017]

[0018] (In formula (I-1), R １１ and R１２ The substituents are a halogen group, an oxa group (-O-), a carbonyl group (>C=O), and a sulfonyl group (>S(=O)). ２ This represents a divalent hydrocarbon group having 1 to 6 carbon atoms, which may contain at least one functional group selected from the group consisting of ). In formula (I-2), R １１ The substituents are a halogen group, an oxa group (-O-), a carbonyl group (>C=O), and a sulfonyl group (>S(=O)). ２ Represents a divalent hydrocarbon group having 1 to 6 carbon atoms, which may contain at least one functional group selected from the group consisting of ). １３ These can be independently substituted with a halogen group, a cyano group (-CN), an oxa group (-O-), a carbonyl group (>C=O), and a sulfonyl group (>S(=O)). ２ This represents a hydrocarbon group having 1 to 12 carbon atoms, which may contain at least one functional group selected from the group consisting of the following:

[0019]

[0020] (In formula (IV), R ４１ is a methylene group (-CH ２ -), ethylene group (-CH ２ CH ２ -), or n-propylene group (-CH ２ CH ２ CH ２ Represents (-). ４２ Each of these independently represents a hydrocarbon group having 1 to 12 carbon atoms, which may contain at least one functional group selected from the group consisting of a halogen group and an oxa group (-O-) as a substituent. ４１ is a methylene group (-CH ２ When h is -, it represents 1 or 2. ４１ is an ethylene group (-CH ２ CH ２ When h is -, h represents an integer from 1 to 4. ４１ is an n-propylene group (-CH ２ CH ２ CH ２h represents an integer of 1 to 6 when it is -).) <8> A non-aqueous electrolyte secondary battery comprising a positive electrode, a negative electrode, the non-aqueous electrolyte according to any one of <1> to <7>, and a separator.

[0021] According to one aspect of the present disclosure, there are provided a non-aqueous electrolyte and a non-aqueous electrolyte secondary battery that can suppress an increase in resistance of the non-aqueous electrolyte secondary battery after high-temperature storage.

[0022] FIG. 1 is a cross-sectional view showing a stacked non-aqueous electrolyte secondary battery which is an example of the non-aqueous electrolyte secondary battery of the present disclosure. FIG. 2 is a cross-sectional view showing a coin-type non-aqueous electrolyte secondary battery which is another example of the non-aqueous electrolyte secondary battery of the present disclosure.

[0023] In describing the present disclosure, description will be given with specific examples; however, the present disclosure is not limited to the following contents without departing from the gist of the present disclosure, and can be implemented with appropriate modifications.

[0024] In the present disclosure, a numerical range expressed using "to" means a range including the numerical values described before and after "to" as the lower limit and the upper limit, respectively. In the numerical ranges described stepwise in the present disclosure, the upper limit or lower limit described in one numerical range may be replaced with the upper limit or lower limit of the numerical range described in other stepwise descriptions. In the numerical ranges described in the present disclosure, the upper limit or lower limit of the numerical range may be replaced with the values shown in the examples. In the present disclosure, when there are a plurality of substances corresponding to each component in the composition, the amount of each component in the composition means the total amount of the plurality of substances present in the composition, unless otherwise specified. In the present disclosure, a combination of preferred embodiments is a more preferred embodiment. In the present disclosure, the term "step" includes not only an independent step, but also a case that cannot be clearly distinguished from other steps, as long as the intended purpose of the step is achieved.

[0025] (1) Non-aqueous electrolyte A A non-aqueous electrolyte according to one aspect of the present disclosure (hereinafter sometimes abbreviated as "non-aqueous electrolyte A") includes a first component. The first component represents at least one selected from the group consisting of a compound represented by the following formula (I-1) (hereinafter also referred to as "compound (I-1)") and a compound represented by the following formula (I-2) (hereinafter also referred to as "compound (I-2)"). Non-aqueous electrolyte A satisfies either the following condition (a) or the following condition (b). Condition (a): The non-aqueous electrolyte further comprises a second component, the second component being at least two selected from the group consisting of the compound represented by the following formula (II) (hereinafter also referred to as "compound (II)"), the compound represented by the following formula (III) (hereinafter also referred to as "compound (III)"), the compound represented by the following formula (IV) (hereinafter also referred to as "compound (IV)"), and the compound represented by the following formula (V) (hereinafter also referred to as "compound (V)") Condition (b): The non-aqueous electrolyte further comprises a second component and a third component, the second component being at least one selected from the group consisting of the compound represented by the following formula (II) (i.e., compound (II)), the compound represented by the following formula (III) (i.e., compound (III-1)), the compound represented by the following formula (IV) (i.e., compound (IV)), and the compound represented by the following formula (V) (i.e., compound (V)), The third component represents at least one compound selected from the group consisting of the following: a compound represented by formula (VI) below (hereinafter also referred to as "compound (VI)"), a compound represented by formula (VII) below (hereinafter also referred to as "compound (VII)"), a compound represented by formula (VIII-1) below (hereinafter also referred to as "compound (VIII-1)"), a compound represented by formula (VIII-2) below (hereinafter also referred to as "compound (VIII-2)"), a compound represented by formula (IX) below (hereinafter also referred to as "compound (IX)"), a compound represented by formula (X) below (hereinafter also referred to as "compound (X)"), a compound represented by formula (XI) below (hereinafter also referred to as "compound (XI)"), and a compound represented by formula (XII) below (hereinafter also referred to as "compound (XII)").

[0026]

[0027] In formula (I-1), R １１ and R１２ each independently represents a C1-6 divalent hydrocarbon group which may contain at least one functional group selected from the group consisting of a halogeno group, an oxa group (-O-), a carbonyl group (>C=O), and a sulfonyl group (>S(=O) ２ ) as a substituent. In formula (I-2), R １１ represents a C1-6 divalent hydrocarbon group which may contain at least one functional group selected from the group consisting of a halogeno group, an oxa group (-O-), a carbonyl group (>C=O), and a sulfonyl group (>S(=O) ２ ) as a substituent. Two R １３ each independently represent a C1-12 hydrocarbon group which may contain at least one functional group selected from the group consisting of a halogeno group, a cyano group (-CN), an oxa group (-O-), a carbonyl group (>C=O), and a sulfonyl group (>S(=O) ２ ) as a substituent.

[0028]

[0029] In formula (II), R ２１ represents a fluorinated hydrocarbon group having 1 to 12 carbon atoms which may contain an oxa group (-O-) as a substituent, or a hydrocarbon group having 1 to 12 carbon atoms containing a fluoro group (-F) as a substituent. M ＋ represents an alkali metal ion, an ammonium ion, an imidazolium ion, a pyridinium ion, a pyrrolidinium ion, a piperidinium ion, or a phosphonium ion. In formula (III), R ３１ represents a methylene group (-CH ２ -), an ethylene group (-CH ２ CH ２ -), or an n-propylene group (-CH ２ CH ２ CH ２ -). In formula (IV), R ４１ represents a methylene group (-CH ２ -), an ethylene group (-CH ２ CH ２ -), or an n-propylene group (-CH ２ CH ２ CH ２Represents (-). ４２ Each of these independently represents a hydrocarbon group having 1 to 12 carbon atoms, which may contain at least one functional group selected from the group consisting of a halogen group and an oxa group (-O-) as a substituent. ４１ is a methylene group (-CH ２ When h is -, it represents 1 or 2. ４１ is an ethylene group (-CH ２ CH ２ When h is -, h represents an integer from 1 to 4. ４１ is an n-propylene group (-CH ２ CH ２ CH ２ When h is -, h represents an integer from 1 to 6. In equation (V), R ５１ is a methylene group (-CH ２ -), ethylene group (-CH ２ CH ２ -), or n-propylene group (-CH ２ CH ２ CH ２ Represents (-). ５２ Each of these independently represents the group represented by formula (v-1), the group represented by formula (v-2), the group represented by formula (v-3), the group represented by formula (v-4), the group represented by formula (v-5), the group represented by formula (v-6), or the group represented by formula (v-7). ５１ is a methylene group (-CH ２ When i is -, it represents either 1 or 2. ５１ is an ethylene group (-CH ２ CH ２ When i is -, it represents an integer from 1 to 4. ５１ is an n-propylene group (-CH ２ CH ２ CH ２ When i is -, i represents an integer from 1 to 6. In equation (v-3), R ５３ This represents a hydrocarbon group having 1 to 12 carbon atoms, which may contain at least one functional group selected from the group consisting of a halogen group and an oxa group (-O-) as a substituent.

[0030]

[0031] In equation (VI), the double line (solid and dotted) represents a single bond (-) or a double bond (=). ６１ represents a halogeno group, a fluorine carbide group having 1 to 12 carbon atoms which may contain an oxa group (-O-) as a substituent, or a hydrocarbon group having 1 to 12 carbon atoms which may contain at least one functional group selected from the group consisting of a fluoro group (-F) and an oxa group (-O-) as a substituent. j represents an integer from 0 to 4. In formula (VII), Q represents a boron atom (B) or a phosphorus atom (P). R ７１ Each independently represents a divalent hydrocarbon group having 1 to 6 carbon atoms, which may contain a single bond (-) or at least one functional group selected from the group consisting of a halogen group and an oxa group (-O-) as a substituent. Each independently represents a halogen group. When Q is a boron atom (B), a represents 1 or 2, when a is 1, b represents 2, and when a is 2, b represents 0. When Q is a phosphorus atom (P), a represents an integer from 1 to 3, when a is 1, b represents 4, when a is 2, b represents 2, and when a is 3, b represents 0. c represents an integer from 1 to 3. M ＋ M represents an alkali metal ion, ammonium ion, imidazolium ion, pyridinium ion, pyrrolidinium ion, piperidinium ion, or phosphonium ion. In formula (VIII-1), M ＋ represents an alkali metal ion, ammonium ion, imidazolium ion, pyridinium ion, pyrrolidinium ion, piperidinium ion, or phosphonium ion. In formula (VIII-2), two M ＋ Each of these independently represents an alkali metal ion, an ammonium ion, an imidazolium ion, a pyridinium ion, a pyrrolidinium ion, a piperidinium ion, or a phosphonium ion. In formula (IX), M ＋ R represents an alkali metal ion, ammonium ion, imidazolium ion, pyridinium ion, pyrrolidinium ion, piperidinium ion, or phosphonium ion. In formula (X), two R １０１Each of these independently represents a fluorine carbide group having 1 to 12 carbon atoms, which may contain a fluoro group (-F), an oxa group (-O-) as a substituent, or a hydrocarbon group having 1 to 12 carbon atoms, which contains a fluoro group (-F) as a substituent. ＋ R represents an alkali metal ion, ammonium ion, imidazolium ion, pyridinium ion, pyrrolidinium ion, piperidinium ion, or phosphonium ion. In formula (XI), R １１１ Each independently represents a halogeno group, a 1-12 carbon atom fluorine carbide group which may contain an oxa group (-O-) as a substituent, or a 1-12 carbon atom hydrocarbon group which may contain at least one functional group selected from the group consisting of a fluoro group (-F) and an oxa group (-O-) as a substituent. m represents an integer from 0 to 2. In formula (XII), the two R １２１ Each of these independently represents a hydrocarbon group having 1 to 12 carbon atoms or a trialkylsilyl group having 3 to 18 carbon atoms.

[0032] The Disclosers have diligently conducted studies to solve the aforementioned problems. As a result, the Disclosers have found that by using a non-aqueous electrolyte containing a first component and at least two types of second components (i.e., satisfying condition 1), or a non-aqueous electrolyte containing a first component, a second component, and a third component (i.e., satisfying condition 2), the increase in resistance of a non-aqueous electrolyte secondary battery after high-temperature storage can be effectively suppressed. Compounds (I-1) to (XII) will be described in detail below.

[0033] (1.1) First component The first component represents at least one selected from the group consisting of compound (I-1) and compound (I-2).

[0034] The total content of the first component in non-aqueous electrolyte A is preferably 0.001% by mass to 5.0% by mass, relative to the total amount of the non-aqueous electrolyte (when the total amount of the non-aqueous electrolyte is considered as 100% by mass). The total content of the first component may be 0.01% by mass or more, 0.1% by mass or more, 0.5% by mass or more, or 0.8% by mass or more. The total content of the first component may be 4.0% by mass or less, 3.0% by mass or less, 2.0% by mass or less, 1.5% by mass or less, 0.5% by mass or less, or 0.3% by mass or less. When the total content of the first component is within the above range, the increase in resistance after high-temperature storage can be suppressed.

[0035] Compound (I-1) is represented by the following formula (I-1). Compound (I-2) is represented by the following formula (I-2).

[0036]

[0037] In formula (I-1), R １１ and R １２ These can be independently substituted with a halogen group, an oxa group (-O-), a carbonyl group (>C=O), and a sulfonyl group (>S(=O)). ２ This represents a divalent hydrocarbon group having 1 to 6 carbon atoms, which may contain at least one functional group selected from the group consisting of ). In formula (I-2), R １１ The substituents are a halogen group, an oxa group (-O-), a carbonyl group (>C=O), and a sulfonyl group (>S(=O)). ２ Represents a divalent hydrocarbon group having 1 to 6 carbon atoms, which may contain at least one functional group selected from the group consisting of ). １３ These can be independently substituted with a halogen group, a cyano group (-CN), an oxa group (-O-), a carbonyl group (>C=O), and a sulfonyl group (>S(=O)). ２ This represents a hydrocarbon group having 1 to 12 carbon atoms, which may contain at least one functional group selected from the group consisting of ).

[0038] R １１ and R １２ The term "divalent hydrocarbon group" as represented by R refers to a hydrocarbon group with two bond positions. １１ and R １２The “divalent hydrocarbon group” represented by may be a linear aliphatic hydrocarbon group, or a hydrocarbon group having at least one structure selected from the group consisting of branched structures, cyclic structures, and carbon-carbon unsaturated bond structures (e.g., carbon-carbon double bond structures and carbon-carbon triple bond structures). The number of these structures is also not limited. (Acyclic) aliphatic hydrocarbon groups, monocyclic aliphatic hydrocarbon groups, polycyclic aliphatic hydrocarbon groups, monocyclic aromatic hydrocarbon groups, and polycyclic aromatic hydrocarbon groups are included in “hydrocarbon groups”. Alkylene groups, alkenylene groups, alkynylene groups, and arylene groups, etc., are also included in “divalent hydrocarbon groups”. １１ and R １２ The substituents are a halogen group, an oxa group (-O-), a carbonyl group (>C=O), and a sulfonyl group (>S(=O)). ２ A divalent hydrocarbon group having 1 to 6 carbon atoms may contain at least one functional group selected from the group consisting of ) ) and the hydrogen atoms of the divalent hydrocarbon group may be substituted with halogen groups (e.g., fluoro group (-F), chloro group (-Cl), bromo group (-Br), and iodine (-I), etc.), and the carbon atoms of the divalent hydrocarbon group may be oxa group (-O-), carbonyl group (>C=O), and sulfonyl group (>S (=O) ) ２ It may be substituted with at least one functional group selected from the group consisting of ), the hydrogen atom of the divalent hydrocarbon group is substituted with a halogeno group, and the carbon atom of the divalent hydrocarbon group is substituted with an oxa group (-O-), a carbonyl group (>C=O), and a sulfonyl group (>S(=O) ２ This means that it may be substituted with at least one functional group selected from the group consisting of ).

[0039] R １１ The number of carbon atoms in the hydrocarbon group represented is preferably 5 or less, more preferably 4 or less, even more preferably 3 or less, and particularly preferably 2 or less. １２ The number of carbon atoms in the hydrocarbon group represented is preferably 5 or less, more preferably 4 or less, even more preferably 3 or less, and particularly preferably 2 or less.

[0040] R １１ For example, the methylene group (-CH２ -), ethylene group (-CH ２ CH ２ -), n-propylene group (-CH ２ CH ２ CH ２ -), and n-butylene group (-CH ２ CH ２ CH ２ CH ２ Examples include methylene group (-CH). ２ -) is preferable. R １２ For example, the methylene group (-CH ２ -), ethylene group (-CH ２ CH ２ -), n-propylene group (-CH ２ CH ２ CH ２ -), and n-butylene group (-CH ２ CH ２ CH ２ CH ２ Examples include methylene group (-CH). ２ -) is preferable.

[0041] R １３ The term "hydrocarbon group" represented by means a hydrocarbon group with one bond position. １３ The "hydrocarbon group" represented by may be an aliphatic hydrocarbon group having a linear structure, or a hydrocarbon group having at least one structure selected from the group consisting of branched structures, cyclic structures, and carbon-carbon unsaturated bond structures (e.g., carbon-carbon double bond structures and carbon-carbon triple bond structures). The number of these structures is also not limited. (Acyclic) aliphatic hydrocarbon groups, monocyclic aliphatic hydrocarbon groups, polycyclic aliphatic hydrocarbon groups, monocyclic aromatic hydrocarbon groups, and polycyclic aromatic hydrocarbon groups are included in "hydrocarbon groups". Alkyl groups, alkenyl groups, alkynyl groups, and aryl groups, etc., are also included in "hydrocarbon groups". １３ This is represented as "a substituent consisting of a halogen group, a cyano group (-CN), an oxa group (-O-), a carbonyl group (>C=O), and a sulfonyl group (>S(=O)" ２A hydrocarbon group having 1 to 12 carbon atoms may contain at least one functional group selected from the group consisting of ), and the hydrogen atoms of the monovalent hydrocarbon group may be substituted with halogen groups (e.g., fluoro groups (-F), chloro groups (-Cl), bromo groups (-Br), and iodine (-I), etc.), and the carbon atoms of the monovalent hydrocarbon group may be halogen groups, cyano groups (-CN), oxa groups (-O-), carbonyl groups (>C=O), and sulfonyl groups (>S(=O)). ２ It may be substituted with at least one functional group selected from the group consisting of ), where the hydrogen atom of the monovalent hydrocarbon group is substituted with a halogeno group, and the carbon atom of the divalent hydrocarbon group is substituted with an oxa group (-O-), a carbonyl group (>C=O), and a sulfonyl group (>S(=O) ２ This means that it may be substituted with at least one functional group selected from the group consisting of ).

[0042] R １３ The number of carbon atoms in the hydrocarbon group represented is preferably 10 or less, more preferably 8 or less, even more preferably 6 or less, and particularly preferably 4 or less.

[0043] R １３ For example, a methyl group (-CH ３ ), ethyl group (-CH ２ CH ３ ), vinyl group (-CH=CH ２ ), n-propyl group (-CH ２ CH ２ CH ３ ), i-propyl group (-CH(CH ３ ) ２ ), n-butyl group (-CH ２ CH ２ CH ２ CH ３ ), s-butyl group (-CH ２ CH (CH ３ ) ２ ), t-butyl group (-C(CH ３ ) ２ ), hexyl group (-CH ２ CH ２ CH ２ CH ２ CH ２ CH ３ ), cyclohexyl group (-C６ H １１ ), and phenyl group (-C ６ H ５ Examples include:

[0044] Examples of compound (I-1) include methylene methane disulfonate (MMDS) represented by the following formula (I-1-1). Examples of compound (I-2) include disulfonic acid esters represented by the following formula (I-2-1). Non-aqueous electrolyte A may contain two or more types of compound (I-1). Non-aqueous electrolyte A may contain two or more types of compound (I-2).

[0045]

[0046] The content of compound (I-1) and compound (I-2) is usually 0.001% to 5.0% by mass relative to the total amount of the non-aqueous electrolyte (when the total amount of the non-aqueous electrolyte is considered to be 100% by mass). The content of compound (I-1) and compound (I-2) may be 0.01% or more by mass, 0.1% or more by mass, 0.5% or more by mass, or 0.8% or more by mass. The content of compound (I-1) and compound (I-2) may be 4.0% or less by mass, 3.0% or less by mass, 2.0% or less by mass, 1.5% or less by mass, 0.5% or less by mass, or 0.3% or less by mass. When the content of compound (I-1) and compound (I-2) is within the above range, the increase in resistance after high-temperature storage can be suppressed.

[0047] (1.2) If condition (a) of the second component is met, the second component represents at least two compounds selected from the group consisting of compound (II), compound (III), compound (IV), and compound (V). If condition (b) is met, the second component represents at least one compound selected from the group consisting of compound (II), compound (III), compound (IV), and compound (V).

[0048] When condition (a) is met (i.e., the non-aqueous electrolyte contains at least two types of second components), the total content of the second components in non-aqueous electrolyte A may be within the following ranges. The total content of the second components is preferably 0.001% by mass to 10% by mass with respect to the total amount of the non-aqueous electrolyte (when the total amount of the non-aqueous electrolyte is considered to be 100% by mass). The total content of the second components may be 0.01% by mass or more, 0.1% by mass or more, 0.3% by mass or more, 0.5% by mass or more, or 0.8% by mass or more. The total content of the second components may be 9.0% by mass or less, 8.0% by mass or less, 5.0% by mass or less, 3.0% by mass or less, 1.0% by mass or less, 0.7% by mass or less, or 0.5% by mass or less. When the total content of the second components is within the above range, the increase in resistance after high-temperature storage can be suppressed.

[0049] When condition (b) is met (i.e., the non-aqueous electrolyte contains a first component, a second component, and a third component), the total content of the second component in non-aqueous electrolyte A may be within the following ranges. Preferably, the total content of the second component is 0.001% by mass to 5.0% by mass, relative to the total amount of the non-aqueous electrolyte (when the total amount of the non-aqueous electrolyte is considered as 100% by mass). The total content of the second component may be 0.01% by mass or more, 0.1% by mass or more, 0.5% by mass or more, or 0.8% by mass or more. The total content of the second component may be 4.0% by mass or less, 3.0% by mass or less, 2.0% by mass or less, 1.5% by mass or less, 0.5% by mass or less, or 0.3% by mass or less. When the total content of the second component is within the above range, the increase in resistance after high-temperature storage can be suppressed.

[0050] (1.2.1) Compound (II) Compound (II) is represented by the following formula (II).

[0051]

[0052] In formula (II), R ２１ This represents a fluorine carbide group having 1 to 12 carbon atoms, which may contain an oxa group (-O-) as a substituent, or a hydrocarbon group having 1 to 12 carbon atoms, which contains a fluoro group (-F) as a substituent. ＋represents an alkali metal ion, an ammonium ion, an imidazolium ion, a pyridinium ion, a pyrrolidinium ion, a piperidinium ion, or a phosphonium ion.

[0053] Compound (II) may sometimes act as an electrolyte described later. In the present disclosure, regardless of its function, the compound (II) contained in the non-aqueous electrolyte is regarded as a "second component".

[0054] In the present disclosure, the term "fluorocarbon group" means a group in which all hydrogen atoms of a hydrocarbon group are substituted with fluorine atoms. The "fluorocarbon group" is a concept including a perfluoroalkyl group. The fluorocarbon group may be a fluorocarbon group having a linear structure, or may be a fluorocarbon group having at least one structure selected from the group consisting of a branched structure, a cyclic structure, and a carbon-carbon unsaturated bond structure (e.g., a carbon-carbon double bond structure and a carbon-carbon triple bond structure). R ２１ The "hydrocarbon group having 1 to 12 carbon atoms which may optionally contain an oxa group (-O-) as a substituent" represented by means that a carbon atom of the hydrocarbon group may optionally be substituted with an oxa group (-O-). The oxa group (-O-) may be located at a terminal position in the fluorocarbon group. For example, the oxa group (-O-) is bonded to the sulfonyl group (>S(=O) ２ ) may be an alkoxy group (-OR) bonded to . R ２１ The "hydrocarbon group having 1 to 12 carbon atoms containing a fluoro group (-F) as a substituent" represented by means a group in which one or more hydrogen atoms of a hydrocarbon group are substituted with fluorine atoms.

[0055] R ２１ The number of carbon atoms of the fluorocarbon group represented by is preferably 10 or less, more preferably 8 or less, still more preferably 6 or less, and particularly preferably 4 or less. R ２１ The number of carbon atoms of the hydrocarbon group represented by is preferably 10 or less, more preferably 8 or less, still more preferably 6 or less, and particularly preferably 4 or less.

[0056] R ２１ examples thereof include a trifluoromethyl group (-CF ３ ), a pentafluoroethyl group (-C２ F ５ ), n-heptafluoropropyl group (-C ３ F ７ ), pentafluorophenyl group (-C ６ F ５ ), trifluoromethoxy group (-OCF ３ ), pentafluoroethoxy group (- OC ２ F ５ ), n-heptafluoropropoxy group (-OC ３ F ７ ), pentafluorophenoxy group (-OC ６ F ５ ), fluoromethyl group (-CH ２ F), difluoromethyl group (-CHF ２ ), 2,2,2-trifluoroethyl group (-CH ２ CF ３ ), p-fluorophenyl group (-C ６ H ４ F), methyl group (-CH ３ ), ethyl group (-CH ２ CH ３ ), vinyl group (-CH=CH ２ ), n-propyl group (-CH ２ CH ２ CH ３ ), i-propyl group (-CH(CH ３ ) ２ ), n-butyl group (-CH ２ CH ２ CH ２ CH ３ ), s-butyl group (-CH ２ CH (CH ３ ) ２ ), t-butyl group (-C(CH ３ ) ２ ), hexyl group (-CH ２ CH ２ CH ２ CH ２ CH ２ CH ３ ), cyclohexyl group (-C ６ H １１ ), phenyl group (-C ６ H ５ ), fluorophenyl group (-C ６ H４ F), trifluoromethylphenyl group (-C ６ H ４ CF ３ ), and trifluoromethoxyphenyl group (-C ６ H ４ OCF ３ Examples include the trifluoromethyl group (-CF ３ ) is preferable.

[0057] M ＋ Examples of alkali metal ions include lithium ions (Li ＋ ), sodium ions (Na ＋ ), and potassium ions (K ＋ ) are some examples. M ＋ Examples of "ammonium ions" represented by the following formula (m1) include the ion represented by M. ＋ An example of an "imidazolium ion" represented by the following formula (m²) is the ion represented by M. ＋ Examples of "pyridinium ions" represented by the formula (m³) below include the ion represented by the following formula: M ＋ Examples of "pyrrolidinium ions" represented by the following formula (m4) include the ion represented by M. ＋ Examples of the "piperidinium ion" represented by the following formula (m5) include the ion represented by M. ＋ Examples of "phosphonium ions" represented by the following formula (m6) include the ion shown below.

[0058]

[0059] In formulas (m1) to (m6), R' is independently a hydrogen atom (-H), or a substituent such as a halogen group, an oxa group (-O-), a carbonyl group (>C=O), or a sulfonyl group (>S(=O)). ２ M represents a hydrocarbon group having 1 to 20 carbon atoms, which may contain at least one functional group selected from the group consisting of a secondary amino group (-NH-) and a tertiary amino group (-N<). ＋ Lithium ion (Li ＋ ) is preferable.

[0060] Compound (II) is lithium trifluoromethanesulfonate (LiSO4), represented by the following formula (II-1). ３ CF ３ Examples include the following. Non-aqueous electrolyte A may contain two or more compounds (II).

[0061]

[0062] The content of compound (II) is usually 0.001% to 5.0% by mass relative to the total amount of the non-aqueous electrolyte (when the total amount of the non-aqueous electrolyte is considered as 100% by mass). The content of compound (II) may be 0.01% or more by mass, 0.1% or more by mass, 0.5% or more by mass, or 0.8% or more by mass. The content of compound (II) may be 4.0% or less by mass, 3.0% or less by mass, 2.0% or less by mass, 1.5% or less by mass, 0.5% or less by mass, or 0.3% or less by mass. When the content of compound (II) is within the above range, the increase in resistance after high-temperature storage can be suppressed.

[0063] (1.2.2) Compound (III) Compound (III) is represented by the following formula (III).

[0064]

[0065] In formula (III), R ３１ is a methylene group (-CH ２ -), ethylene group (-CH ２ CH ２ -), or n-propylene group (-CH ２ CH ２ CH ２ It represents (-).

[0066] R ３１ is an ethylene group (-CH ２ CH ２ -) is preferable.

[0067] Examples of compound (III) include 1,3,2-dioxathiolane 2,2-dioxide (DTD) represented by the following formula (III-1). Non-aqueous electrolyte A may contain two or more types of compound (III).

[0068]

[0069] The content of compound (III) is usually 0.001% to 5.0% by mass relative to the total amount of the non-aqueous electrolyte (when the total amount of the non-aqueous electrolyte is considered as 100% by mass). The content of compound (III) may be 0.01% or more by mass, 0.1% or more by mass, 0.5% or more by mass, or 0.8% or more by mass. The content of compound (III) may be 4.0% or less by mass, 3.0% or less by mass, 2.0% or less by mass, 1.5% or less by mass, 0.5% or less by mass, or 0.3% or less by mass. When the content of compound (III) is within the above range, the increase in resistance after high-temperature storage can be suppressed.

[0070] (1.2.3) Compound (IV) Compound (IV) is represented by the following formula (IV).

[0071]

[0072] In formula (IV), R ４１ is a methylene group (-CH ２ -), ethylene group (-CH ２ CH ２ -), or n-propylene group (-CH ２ CH ２ CH ２ Represents (-). ４２ Each of these independently represents a hydrocarbon group having 1 to 12 carbon atoms, which may contain at least one functional group selected from the group consisting of a halogen group and an oxa group (-O-) as a substituent. ４１ is a methylene group (-CH ２ When h is -, it represents 1 or 2. ４１ is an ethylene group (-CH ２ CH ２ When h is -, h represents an integer from 1 to 4. ４１ is an n-propylene group (-CH ２ CH ２ CH ２ When h is -, it represents an integer from 1 to 6.

[0073] R ４１ is an ethylene group (-CH ２ CH ２ -) is preferable.

[0074] R４２ The term "hydrocarbon group" as represented by R refers to a hydrocarbon group with one bond position (i.e., a monovalent hydrocarbon group). ４２ The "hydrocarbon group" represented by may be an aliphatic hydrocarbon group having a linear structure, or a hydrocarbon group having at least one structure selected from the group consisting of branched structures, cyclic structures, and carbon-carbon unsaturated bond structures (e.g., carbon-carbon double bond structures and carbon-carbon triple bond structures). The number of these structures is also not limited. (Acyclic) aliphatic hydrocarbon groups, monocyclic aliphatic hydrocarbon groups, polycyclic aliphatic hydrocarbon groups, monocyclic aromatic hydrocarbon groups, and polycyclic aromatic hydrocarbon groups are included in "hydrocarbon groups". Alkyl groups, alkenyl groups, alkynyl groups, and aryl groups, etc., are also included in "monovalent hydrocarbon groups". ４２ The expression "a hydrocarbon group having 1 to 12 carbon atoms which may contain at least one functional group selected from the group consisting of a halogen group (-X) and an oxa group (-O-) as a substituent" means that the hydrogen atoms of the monovalent hydrocarbon group may be substituted with a halogen group (-X), the carbon atoms of the monovalent hydrocarbon group may be substituted with an oxa group (-O-), and the hydrogen atoms of the monovalent hydrocarbon group may be substituted with a halogen group (-X) and the carbon atoms of the monovalent hydrocarbon group may be substituted with an oxa group (-O-).

[0075] R ４２ The number of carbon atoms in the hydrocarbon group represented is preferably 8 or less, more preferably 5 or less.

[0076] R ４２ For example, a methyl group (-CH ３ ), ethyl group (-CH ２ CH ３ ), vinyl group (-CH=CH ２ ), n-propyl group (-CH ２ CH ２ CH ３ ), i-propyl group (-CH(CH ３ ) ２ ), n-butyl group (-CH ２ CH ２ CH ２ CH ３ ), s-butyl group (-CH ２CH (CH ３ ) ２ ), t-butyl group (-C(CH ３ ) ２ ), hexyl group (-CH ２ CH ２ CH ２ CH ２ CH ２ CH ３ ), cyclohexyl group (-C ６ H １１ ), phenyl group (-C ６ H ５ ), fluorophenyl group (-C ６ H ４ F), trifluoromethylphenyl group (-C ６ H ４ CF ３ ), and trifluoromethoxyphenyl group (-C ６ H ４ OCF ３ Examples include the n-propyl group (-CH ２ CH ２ CH ３ ) is preferable.

[0077] h is preferably 0 or 1.

[0078] Examples of compound (IV) include sulfate esters represented by the following formula (IV-1). Non-aqueous electrolyte A may contain two or more types of compound (IV).

[0079]

[0080] The content of compound (IV) is usually 0.001% to 5.0% by mass relative to the total amount of the non-aqueous electrolyte (when the total amount of the non-aqueous electrolyte is considered as 100% by mass). The content of compound (IV) may be 0.01% or more by mass, 0.1% or more by mass, 0.5% or more by mass, or 0.8% or more by mass. The content of compound (IV) may be 4.0% or less by mass, 3.0% or less by mass, 2.0% or less by mass, 1.5% or less by mass, 0.5% or less by mass, or 0.3% or less by mass. When the content of compound (IV) is within the above range, the increase in resistance after high-temperature storage can be suppressed.

[0081] (1.2.4) Compound (V) Compound (V) is represented by the following formula (V).

[0082]

[0083] In formula (V), R ５１ is a methylene group (-CH ２ -), ethylene group (-CH ２ CH ２ -), or n-propylene group (-CH ２ CH ２ CH ２ Represents (-). ５２ Each of these independently represents the group represented by formula (v-1), the group represented by formula (v-2), the group represented by formula (v-3), the group represented by formula (v-4), the group represented by formula (v-5), the group represented by formula (v-6), or the group represented by formula (v-7). ５１ is a methylene group (-CH ２ When i is -, it represents either 1 or 2. ５１ is an ethylene group (-CH ２ CH ２ When i is -, it represents an integer from 1 to 4. ５１ is an n-propylene group (-CH ２ CH ２ CH ２ When i is -, i represents an integer from 1 to 6. In equation (v-3), R ５３ This represents a hydrocarbon group having 1 to 12 carbon atoms, which may contain at least one functional group selected from the group consisting of a halogen group and an oxa group (-O-) as a substituent.

[0084] R ５１ is an ethylene group (-CH ２ CH ２ -), or n-propylene group (-CH ２ CH ２ CH ２ It is preferable that it be -, and the ethylene group (-CH ２ CH ２ -) is more preferable.

[0085] In equations (v-1), (v-2), (v-3), (v-4), (v-5), (v-6), and (v-7), the dashed line has a tip of R. ５１The methylene group (-CH ２ -) ``Ethylene group (-CH ２ CH ２ -) or "n-propylene group (-CH ２ CH ２ CH ２ -) means that it is bonded as a substituent to the hydrogen atom. The two wavy lines in (v-7) have R at the end of each line. ５１ The methylene group (-CH ２ -) ``Ethylene group (-CH ２ CH ２ -) or "n-propylene group (-CH ２ CH ２ CH ２ -) means that it is bonded as a substituent to a hydrogen atom. For example, the ends of the two wavy lines are R ５１ It may be bonded to the same carbon atom or to different carbon atoms.

[0086] R ５２ Preferably, the group is represented by formula (v-1), formula (v-4), formula (v-5), formula (v-6), or formula (v-7), with the group represented by formula (v-1) being more preferred.

[0087] i is preferably 0 or 1.

[0088] R ５３ The "hydrocarbon group" represented by R ４２ This is similar to the example given for the hydrocarbon group.

[0089] R ５３ The number of carbon atoms in the hydrocarbon group represented is preferably 8 or less, more preferably 5 or less.

[0090] R ５３ For example, a methyl group (-CH ３ ), ethyl group (-CH ２ CH ３ ), vinyl group (-CH=CH ２ ), n-propyl group (-CH ２ CH ２ CH ３ ), i-propyl group (-CH(CH ３ )２ ), n-butyl group (-CH ２ CH ２ CH ２ CH ３ ), s-butyl group (-CH ２ CH (CH ３ ) ２ ), t-butyl group (-C(CH ３ ) ２ ), hexyl group (-CH ２ CH ２ CH ２ CH ２ CH ２ CH ３ ), cyclohexyl group (-C ６ H １１ ), phenyl group (-C ６ H ５ ), fluorophenyl group (-C ６ H ４ F), trifluoromethylphenyl group (-C ６ H ４ CF ３ ), and trifluoromethoxyphenyl group (-C ６ H ４ OCF ３ Examples include the methyl group (-CH ３ ) is preferable.

[0091] Examples of compound (V) include sulfate esters represented by the following formula (V-1), sulfate esters represented by the following formula (V-2), sulfate esters represented by the following formula (V-3), sulfate esters represented by the following formula (V-4), sulfate esters represented by the following formula (V-5), and sulfate esters represented by the following formula (V-6). Non-aqueous electrolyte A may contain two or more types of compound (V).

[0092]

[0093] The compound represented by formula (V) (i.e., compound (V)) is preferably at least one selected from the group consisting of the compound represented by formula (V-1), the compound represented by formula (V-2), the compound represented by formula (V-3), the compound represented by formula (V-4), the compound represented by formula (V-5), the compound represented by formula (V-6), and the compound represented by formula (V-7). This can suppress the increase in resistance after high-temperature storage.

[0094] The content of compound (V) is usually 0.001% to 5.0% by mass relative to the total amount of the non-aqueous electrolyte (when the total amount of the non-aqueous electrolyte is considered as 100% by mass). The content of compound (V) may be 0.01% or more by mass, 0.1% or more by mass, 0.5% or more by mass, or 0.8% or more by mass. The content of compound (V) may be 4.0% or less by mass, 3.0% or less by mass, 2.0% or less by mass, 1.5% or less by mass, 0.5% or less by mass, or 0.3% or less by mass. When the content of compound (V) is within the above range, the increase in resistance after high-temperature storage can be suppressed.

[0095] (1.3) Third component The third component is at least one selected from the group consisting of compound (VI), compound (VII), compound (VIII-1), compound (VIII-2), compound (IX), compound (X), compound (XI), and compound (XII).

[0096] When condition (b) is met (i.e., the non-aqueous electrolyte contains a first component, a second component, and a third component), the total content of the third component in non-aqueous electrolyte A may be within the following ranges: The total content of the third component is preferably 0.001% by mass to 20.0% by mass, relative to the total amount of the non-aqueous electrolyte (when the total amount of the non-aqueous electrolyte is considered as 100% by mass). The total content of the third component may be 0.01% by mass or more, 0.05% by mass or more, 0.1% by mass or more, 0.5% by mass or more, or 0.8% by mass or more. The total content of the third component may be 15.0% by mass or less, 10.0% by mass or less, 5.0% by mass or less, 2.0% by mass or less, 0.5% by mass or less, 0.3% by mass or less, or 0.15% by mass or less. When the total content of the third component is within the above range, the increase in resistance after high-temperature storage can be suppressed.

[0097] (1.3.1) Compound (VI) Compound (VI) is represented by the following formula (VI).

[0098]

[0099] In equation (VI), the double line (solid and dotted) represents a single bond (-) or a double bond (=). ６１ represents a halogeno group, a fluorine carbide group having 1 to 12 carbon atoms which may contain an oxa group (-O-) as a substituent, or a hydrocarbon group having 1 to 12 carbon atoms which may contain at least one functional group selected from the group consisting of a fluoro group (-F) and an oxa group (-O-) as a substituent. j represents an integer from 0 to 4.

[0100] When the double line (solid and dotted) represents a single bond (-), it means that compound (VI) is a propensultone compound. When the double line (solid and dotted) represents a double bond (=), it means that compound (VI) is a propensultone compound.

[0101] R ６１ The "fluorine carbide group" represented by R ２１ This is similar to the example given as a "fluorine carbide group" represented by R. ６１ The expression "a hydrocarbon group having 1 to 12 carbon atoms which may contain at least one functional group selected from the group consisting of a fluoro group (-F) and an oxa group (-O-) as a substituent" means that the hydrogen atoms of the monovalent hydrocarbon group may be substituted with a fluoro group (-F), the carbon atoms of the monovalent hydrocarbon group may be substituted with an oxa group (-O-), and the hydrogen atoms of the monovalent hydrocarbon group may be substituted with a fluoro group (-F) and the carbon atoms of the monovalent hydrocarbon group may be substituted with an oxa group (-O-).

[0102] R ６１ The number of carbon atoms in the fluorine carbide group represented by is preferably 10 or less, more preferably 8 or less, even more preferably 6 or less, and particularly preferably 4 or less. ６１ The number of carbon atoms in the hydrocarbon group represented is preferably 10 or less, more preferably 8 or less, even more preferably 6 or less, and particularly preferably 4 or less.

[0103] R６１ Examples include fluoro groups (-F) and trifluoromethyl groups (-CF) ３ ), pentafluoroethyl group (-C ２ F ５ ), n-heptafluoropropyl group (-C ３ F ７ ), pentafluorophenyl group (-C ６ F ５ ), trifluoromethoxy group (-OCF ３ ), pentafluoroethoxy group (-OC ２ F ５ ), n-heptafluoropropoxy group (-OC ３ F ７ ), pentafluorophenoxy group (-OC ６ F ５ ), fluoromethyl group (-CH ２ F), difluoromethyl group (-CHF ２ ), 2,2,2-trifluoroethyl group (-CH ２ CF ３ ), p-fluorophenyl group (-C ６ H ４ F), methyl group (-CH ３ ), ethyl group (-CH ２ CH ３ ), vinyl group (-CH=CH ２ ), n-propyl group (-CH ２ CH ２ CH ３ ), i-propyl group (-CH(CH ３ ) ２ ), n-butyl group (-CH ２ CH ２ CH ２ CH ３ ), s-butyl group (-CH ２ CH (CH ３ ) ２ ), t-butyl group (-C(CH ３ ) ２ ), hexyl group (-CH ２ CH ２ CH ２ CH ２ CH ２ CH ３ ), cyclohexyl group (-C ６ H １１), phenyl group (-C ６ H ５ ), fluorophenyl group (-C ６ H ４ F), trifluoromethylphenyl group (-C ６ H ４ CF ３ ), and trifluoromethoxyphenyl group (-C ６ H ４ OCF ３ Examples include the fluoro group (-F) or the trifluoromethyl group (-CF). ３ ) is preferable.

[0104] j is preferably 0 or 1.

[0105] Examples of compound (VI) include 1,3-propanesultone (PS) represented by the following formula (VI-1), sultone represented by the following formula (VI-2), sultone represented by the following formula (VI-3), sultone represented by the following formula (VI-4), 1-propene-1,3-sultone (PRS) represented by the following formula (VI-5), sultone represented by the following formula (VI-6), sultone represented by the following formula (VI-7), and sultone represented by the following formula (VI-8). Non-aqueous electrolyte A may contain two or more types of compound (VI).

[0106]

[0107] The content of compound (VI) is usually 0.001% to 5.0% by mass relative to the total amount of the non-aqueous electrolyte (when the total amount of the non-aqueous electrolyte is considered as 100% by mass). The content of compound (VI) may be 0.01% or more by mass, 0.1% or more by mass, 0.5% or more by mass, or 0.8% or more by mass. The content of compound (VI) may be 4.0% or less by mass, 3.0% or less by mass, 2.0% or less by mass, 1.5% or less by mass, 0.5% or less by mass, or 0.3% or less by mass. When the content of compound (VI) is within the above range, the increase in resistance after high-temperature storage can be suppressed.

[0108] (1.3.2) Compound (VII) Compound (VII) is represented by the following formula (VII).

[0109]

[0110] In formula (VII), Q represents a boron atom (B) or a phosphorus atom (P). ７１ Each independently represents a divalent hydrocarbon group having 1 to 6 carbon atoms, which may contain a single bond (-) or at least one functional group selected from the group consisting of a halogen group and an oxa group (-O-) as a substituent. Each independently represents a halogen group. When Q is a boron atom (B), a represents 1 or 2, when a is 1, b represents 2, and when a is 2, b represents 0. When Q is a phosphorus atom (P), a represents an integer from 1 to 3, when a is 1, b represents 4, when a is 2, b represents 2, and when a is 3, b represents 0. c represents an integer from 1 to 3. M ＋ This represents alkali metal ions, ammonium ions, imidazolium ions, pyridinium ions, pyrrolidinium ions, piperidinium ions, or phosphonium ions.

[0111] Compound (VII) may also act as an electrolyte, as described later. In this disclosure, regardless of its function, compound (VII) contained in a non-aqueous electrolyte is considered the "third component."

[0112] When Q is a boron atom, compound (VII) is a borate. When Q is a phosphorus atom, compound (VII) is a phosphate.

[0113] R ７１ The "single bond (-)" represented by R ７１ This means that the carbonyl groups (C=O) at both ends are directly bonded together, forming an oxalate ligand (oxalate ion ligand). ７１ The expression "a divalent hydrocarbon group having 1 to 6 carbon atoms which may contain at least one functional group selected from the group consisting of a halogen group and an oxa group (-O-) as a substituent" means that the hydrogen atoms of the divalent hydrocarbon group may be substituted with a halogen group, the carbon atoms of the divalent hydrocarbon group may be substituted with an oxa group (-O-), and the hydrogen atoms of the divalent hydrocarbon group may be substituted with a halogen group and the carbon atoms of the divalent hydrocarbon group may be substituted with an oxa group (-O-).

[0114] R ７１ The number of carbon atoms in the hydrocarbon group represented is preferably 5 or less, more preferably 4 or less, even more preferably 3 or less, and particularly preferably 2 or less.

[0115] R ７１ For example, a single bond (-), a methylene group (-CH ２ -), ethylene group (-CH ２ CH ２ -), and n-propylene group (-CH ２ CH ２ CH ２ Examples include (-). Among these, a single bond (-) is preferred.

[0116] Examples of X include fluoro groups (-F), chloro groups (-Cl), bromo groups (-Br), and iodine (-I). Among these, fluoro groups (-F) are preferred.

[0117] When Q is a boron atom (B), it is preferable that a is 2, b is 0, and c is 1.

[0118] When Q is a phosphorus atom (P), it is preferable that a is 1, b is 4, and c is 1.

[0119] M in equation (VII) ＋ M in equation (II) ＋ This is similar to the example given.

[0120] Examples of compound (VII) include lithium bis(oxalato)borate (LiBOB) represented by the following formula (VII-1), lithium difluorooxalatoborate (LiDFOB) represented by the following formula (VII-2), lithium tetrafluorooxalatophosphate (LiTFOP) represented by the following formula (VII-3), and lithium difluorobis(oxalato)phosphate (LiDFBOP) represented by the following formula (VII-4). Non-aqueous electrolyte A may contain two or more types of compound (VII).

[0121]

[0122] The content of compound (VII) is usually 0.001% to 5.0% by mass relative to the total amount of the non-aqueous electrolyte (when the total amount of the non-aqueous electrolyte is considered as 100% by mass). The content of compound (VII) may be 0.01% or more by mass, 0.1% or more by mass, 0.5% or more by mass, or 0.8% or more by mass. The content of compound (VII) may be 4.0% or less by mass, 3.0% or less by mass, 2.0% or less by mass, 1.5% or less by mass, 0.5% or less by mass, or 0.3% or less by mass. When the content of compound (VII) is within the above range, the increase in resistance after high-temperature storage can be suppressed.

[0123] (1.3.3) Compound (VIII) Compound (VIII) is represented by the following formula (VIII).

[0124]

[0125] In formula (VIII-1), M ＋ represents an alkali metal ion, ammonium ion, imidazolium ion, pyridinium ion, pyrrolidinium ion, piperidinium ion, or phosphonium ion. In formula (VIII-2), two M ＋ Each of these independently represents an alkali metal ion, ammonium ion, imidazolium ion, pyridinium ion, pyrrolidinium ion, piperidinium ion, or phosphonium ion.

[0126] Compound (VIII-1) may also act as an electrolyte, as described later. In this disclosure, regardless of its function, compound (VIII-1) contained in a non-aqueous electrolyte is considered a "third component."

[0127] M in equations (VIII-1) and (VIII-2) ＋ M in equation (II) ＋ This is similar to the example given.

[0128] Compound (VIII-1) is lithium difluorophosphate (LiPO) represented by the following formula (VIII-1-1) ２ F ２ Examples include the following. Compound (VIII-2) is lithium monofluorophosphate (Li) represented by the following formula (VIII-2-1) ２PO ３ Examples include F). Non-aqueous electrolyte A may contain two or more compounds (VIII-1). Non-aqueous electrolyte A may contain two or more compounds (VIII-2).

[0129]

[0130] The content of compound (VIII-1) and compound (VIII-2) is usually 0.001% to 5.0% by mass relative to the total amount of the non-aqueous electrolyte (when the total amount of the non-aqueous electrolyte is considered to be 100% by mass). The content of compound (VIII-1) and compound (VIII-2) may be 0.01% or more by mass, 0.1% or more by mass, 0.5% or more by mass, or 0.8% or more by mass. The content of compound (VIII-1) and compound (VIII-2) may be 4.0% or less by mass, 3.0% or less by mass, 2.0% or less by mass, 1.5% or less by mass, 0.5% or less by mass, or 0.3% or less by mass. When the content of compound (VIII-1) and compound (VIII-2) is within the above range, the increase in resistance after high-temperature storage can be suppressed.

[0131] (1.3.4) Compound (IX) Compound (IX) is represented by the following formula (IX).

[0132]

[0133] In formula (IX), M ＋ This represents alkali metal ions, ammonium ions, imidazolium ions, pyridinium ions, pyrrolidinium ions, piperidinium ions, or phosphonium ions.

[0134] Compound (IX) may also act as an electrolyte, as described later. In this disclosure, regardless of its function, compound (IX) contained in a non-aqueous electrolyte is considered a "third component."

[0135] M in equation (IX) ＋ M in equation (II) ＋ This is similar to the example given. M ＋ Lithium ion (Li ＋ ) is preferable.

[0136] The compound (IX) is lithium fluorosulfonate (LiSO4), represented by the following formula (IX-1). ３ Examples include F). Non-aqueous electrolyte A may contain two or more compounds (IX).

[0137]

[0138] The content of compound (IX) is usually 0.001% to 5.0% by mass relative to the total amount of the non-aqueous electrolyte (when the total amount of the non-aqueous electrolyte is considered as 100% by mass). The content of compound (IX) may be 0.01% or more by mass, 0.1% or more by mass, 0.5% or more by mass, or 0.8% or more by mass. The content of compound (IX) may be 4.0% or less by mass, 3.0% or less by mass, 2.0% or less by mass, 1.5% or less by mass, 0.5% or less by mass, or 0.3% or less by mass. When the content of compound (IX) is within the above range, the increase in resistance after high-temperature storage can be suppressed.

[0139] (1.3.5) Compound (X) Compound (X) is represented by the following formula (X).

[0140]

[0141] In equation (X), two R １０１ Each of these independently represents a fluorine carbide group having 1 to 12 carbon atoms, which may contain a fluoro group (-F), an oxa group (-O-) as a substituent, or a hydrocarbon group having 1 to 12 carbon atoms, which contains a fluoro group (-F) as a substituent. ＋ This represents alkali metal ions, ammonium ions, imidazolium ions, pyridinium ions, pyrrolidinium ions, piperidinium ions, or phosphonium ions.

[0142] Compound (X) may also act as an electrolyte as described later. In this disclosure, regardless of its function, compound (X) contained in a non-aqueous electrolyte is considered a "third component".

[0143] R １０１ The "fluorine carbide group" represented by R ２１ This is similar to the example given for the fluorine carbide group. １０１ The "hydrocarbon group" represented by R ２１This is similar to the example given for the hydrocarbon group.

[0144] R １０１ The number of carbon atoms in the fluorine carbide group represented by is preferably 10 or less, more preferably 8 or less, even more preferably 6 or less, and particularly preferably 4 or less. １０１ The number of carbon atoms in the hydrocarbon group represented is preferably 10 or less, more preferably 8 or less, even more preferably 6 or less, and particularly preferably 4 or less.

[0145] R １０１ Examples include fluoro groups (-F) and trifluoromethyl groups (-CF) ３ ), pentafluoroethyl group (-C ２ F ５ ), n-heptafluoropropyl group (-C ３ F ７ ), pentafluorophenyl group (-C ６ F ５ ), trifluoromethoxy group (-OCF ３ ), pentafluoroethoxy group (-OC ２ F ５ ), n-heptafluoropropoxy group (-OC ３ F ７ ), pentafluorophenoxy group (-OC ６ F ５ ), fluoromethyl group (-CH ２ F), difluoromethyl group (-CHF ２ ), 2,2,2-trifluoroethyl group (-CH ２ CF ３ ), p-fluorophenyl group (-C ６ H ４ F), methyl group (-CH ３ ), ethyl group (-CH ２ CH ３ ), vinyl group (-CH=CH ２ ), n-propyl group (-CH ２ CH ２ CH ３ ), i-propyl group (-CH(CH ３ ) ２ ), n-butyl group (-CH ２ CH ２ CH ２ CH ３), s-butyl group (-CH ２ CH (CH ３ ) ２ ), t-butyl group (-C(CH ３ ) ２ ), hexyl group (-CH ２ CH ２ CH ２ CH ２ CH ２ CH ３ ), cyclohexyl group (-C ６ H １１ ), phenyl group (-C ６ H ５ ), fluorophenyl group (-C ６ H ４ F), trifluoromethylphenyl group (-C ６ H ４ CF ３ ), and trifluoromethoxyphenyl group (-C ６ H ４ OCF ３ Examples include the fluoro group (-F) or the trifluoromethyl group (-CF). ３ ) is preferable.

[0146] M in equation (X) ＋ M in equation (II) ＋ This is similar to the example given. M ＋ Lithium ion (Li ＋ ) is preferable.

[0147] Examples of compound (X) include lithium bis(fluorosulfonyl)imide (LiFSI) represented by the following formula (X-1), and lithium bis(trifluoromethylsulfonyl)imide (LiTFSI) represented by the following formula (X-2). Non-aqueous electrolyte A may contain two or more types of compound (X).

[0148]

[0149] The content of compound (X) is usually 0.001% to 20% by mass relative to the total amount of the non-aqueous electrolyte (when the total amount of the non-aqueous electrolyte is considered to be 100% by mass). The content of compound (X) may be 0.01% or more by mass, 0.1% or more by mass, 0.5% or more by mass, or 0.8% or more by mass. The content of compound (X) may be 15.0% or less by mass, 10.0% or less by mass, 5.0% or less by mass, 2.0% or less by mass, 0.5% or less by mass, or 0.3% or less by mass. When the content of compound (X) is within the above range, the increase in resistance after high-temperature storage can be suppressed.

[0150] (1.3.6) Compound (XI) Compound (XI) is represented by formula (XI).

[0151]

[0152] In formula (XI), R １１１ Each of these independently represents a halogen group, a fluorine carbide group having 1 to 12 carbon atoms which may contain an oxa group (-O-) as a substituent, or a hydrocarbon group having 1 to 12 carbon atoms which may contain at least one functional group selected from the group consisting of a fluoro group (-F) and an oxa group (-O-) as a substituent. m represents an integer from 0 to 2.

[0153] R １１１ The "fluorine carbide group" represented by R ２１ This is similar to the example given for the fluorine carbide group. １０１ The "hydrocarbon group" represented by R ６１ This is similar to the example given for the hydrocarbon group.

[0154] R １１１ The number of carbon atoms in the fluorine carbide group represented by is preferably 10 or less, more preferably 8 or less, even more preferably 6 or less, and particularly preferably 4 or less. １１１ The number of carbon atoms in the hydrocarbon group represented is preferably 10 or less, more preferably 8 or less, even more preferably 6 or less, and particularly preferably 4 or less.

[0155] R １１１ Examples include fluoro groups (-F) and trifluoromethyl groups (-CF) ３ ), pentafluoroethyl group (-C ２F ５ ), n-heptafluoropropyl group (-C ３ F ７ ), pentafluorophenyl group (-C ６ F ５ ), trifluoromethoxy group (-OCF ３ ), pentafluoroethoxy group (-OC ２ F ５ ), n-heptafluoropropoxy group (-OC ３ F ７ ), pentafluorophenoxy group (-OC ６ F ５ ), fluoromethyl group (-CH ２ F), difluoromethyl group (-CHF ２ ), 2,2,2-trifluoroethyl group (-CH ２ CF ３ ), p-fluorophenyl group (-C ６ H ４ F), methyl group (-CH ３ ), ethyl group (-CH ２ CH ３ ), vinyl group (-CH=CH ２ ), n-propyl group (-CH ２ CH ２ CH ３ ), i-propyl group (-CH(CH ３ ) ２ ), n-butyl group (-CH ２ CH ２ CH ２ CH ３ ), s-butyl group (-CH ２ CH (CH ３ ) ２ ), t-butyl group (-C(CH ３ ) ２ ), hexyl group (-CH ２ CH ２ CH ２ CH ２ CH ２ CH ３ ), cyclohexyl group (-C ６ H １１ ), phenyl group (-C ６ H ５ ), fluorophenyl group (-C ６ H ４F), trifluoromethylphenyl group (-C ６ H ４ CF ３ ), and trifluoromethoxyphenyl group (-C ６ H ４ OCF ３ Examples include the fluoro group (-F) or the trifluoromethyl group (-CF). ３ ) is preferable.

[0156] m is preferably 0.

[0157] Examples of compound (XI) include vinylene carbonate (VC) represented by the following formula (XI-1), carbonate represented by the following formula (XI-2), and carbonate (TFPC) represented by the following formula (XI-3). Non-aqueous electrolyte A may contain two or more types of compound (XI).

[0158]

[0159] The content of compound (XI) is usually 0.001% to 5.0% by mass relative to the total amount of the non-aqueous electrolyte (when the total amount of the non-aqueous electrolyte is considered as 100% by mass). The content of compound (XI) may be 0.01% or more by mass, 0.1% or more by mass, 0.5% or more by mass, or 0.8% or more by mass. The content of compound (XI) may be 4.0% or less by mass, 3.0% or less by mass, 2.0% or less by mass, 1.5% or less by mass, 0.5% or less by mass, or 0.3% or less by mass. When the content of compound (XI) is within the above range, the increase in resistance after high-temperature storage can be suppressed.

[0160] (1.3.7) Compound (XII) Compound (XII) is represented by formula (XII).

[0161]

[0162] In equation (XII), two R １２１ Each of these independently represents a hydrocarbon group having 1 to 12 carbon atoms or a trialkylsilyl group having 3 to 18 carbon atoms.

[0163] R １２１ The "trialkylsilyl group with 3 to 18 carbon atoms" represented by -SiR ３As indicated by (R: hydrocarbon), it is a group in which three hydrocarbon groups are bonded to a silicon atom, and the number of carbon atoms represents the total number of carbon atoms in the three hydrocarbon groups.

[0164] R １２１ The number of carbon atoms in the hydrocarbon group represented by is preferably 2 or more, more preferably 3 or more, preferably 10 or less, more preferably 8 or less, and even more preferably 6 or less. １２１ The number of carbon atoms in the trialkylsilyl group represented by is preferably 12 or less, more preferably 9 or less, even more preferably 6 or less, and particularly preferably 4 or less.

[0165] R １２１ Examples of hydrocarbon groups represented include the methyl group (-CH ３ ), ethyl group (-CH ２ CH ３ ), vinyl group (-CH=CH ２ ), n-propyl group (-CH ２ CH ２ CH ３ ), i-propyl group (-CH(CH ３ ) ２ ), n-butyl group (-CH ２ CH ２ CH ２ CH ３ ), s-butyl group (-CH ２ CH (CH ３ ) ２ ), t-butyl group (-C(CH ３ ) ２ ), cyclohexyl group (-C ６ H １１ ), and phenyl group (-C ６ H ５ Examples include: １２１ Examples of trialkylsilyl groups represented by this include the trimethylsilyl group (-Si(CH ３ ) ３ ), and triethylsilyl group (-Si(CH ２ CH ３ ) ３ Examples include i-propyl group (-CH(CH ３ ) ２ ), cyclohexyl group (-C ６ H １１), or trimethylsilyl group (-Si(CH ３ ) ３ ) is preferable.

[0166] Examples of compound (XII) include N,N'-di-i-propylcarbodiimide (DIC) represented by the following formula (XII-1), N,N'-dicyclohexylcarbodiimide (DCC) represented by the following formula (XII-2), and N,N'-bis(trimethylsilyl)carbodiimide represented by the following formula (XII-3). Non-aqueous electrolyte A may contain two or more types of compound (XII).

[0167]

[0168] The content of compound (XII) is usually 0.001% to 5.0% by mass relative to the total amount of the non-aqueous electrolyte (when the total amount of the non-aqueous electrolyte is considered as 100% by mass). The content of compound (XII) may be 0.01% or more by mass, 0.1% or more by mass, 0.5% or more by mass, or 0.8% or more by mass. The content of compound (XII) may be 4.0% or less by mass, 3.0% or less by mass, 2.0% or less by mass, 1.5% or less by mass, 0.5% or less by mass, or 0.3% or less by mass. When the content of compound (XII) is within the above range, the increase in resistance after high-temperature storage can be suppressed.

[0169] (1.4) Preferred Embodiments The non-aqueous electrolyte preferably contains the first component and satisfies the following condition (b1): Condition (b1): The non-aqueous electrolyte further contains a second component and a third component, the second component represents a compound represented by formula (V), the third component represents one selected from the group consisting of a compound represented by formula (VI), a compound represented by formula (VII), a compound represented by formula (VIII-1), a compound represented by formula (VIII-2), a compound represented by formula (IX), a compound represented by formula (X), a compound represented by formula (XI), and a compound represented by formula (XII), the content of the first component is 0.05% by mass to 0.5% by mass or less with respect to the total amount of the non-aqueous electrolyte (when the total amount of the non-aqueous electrolyte is 100% by mass), the content of the second component is 0.05% by mass to 0.5% by mass or less with respect to the total amount of the non-aqueous electrolyte (when the total amount of the non-aqueous electrolyte is 100% by mass), The content of the third component is preferably 0.05% to 0.5% by mass or less relative to the total amount of the non-aqueous electrolyte (when the total amount of the non-aqueous electrolyte is considered to be 100% by mass). This allows the non-aqueous electrolyte to further suppress the increase in resistance after high-temperature storage of the non-aqueous electrolyte secondary battery.

[0170] The non-aqueous electrolyte preferably contains the first component and satisfies either condition (a2) or condition (b2). Condition (a2): The non-aqueous electrolyte further contains the second component, the second component represents the compound represented by formula (IV) and the compound represented by formula (V), the content of the first component is 0.05% by mass to 0.5% by mass or less with respect to the total amount of the non-aqueous electrolyte (when the total amount of the non-aqueous electrolyte is 100% by mass), and the content of the second component is 0.05% by mass to 0.5% by mass or less with respect to the total amount of the non-aqueous electrolyte (when the total amount of the non-aqueous electrolyte is 100% by mass). Condition (b2): The non-aqueous electrolyte further contains the second component and the third component, the second component represents the compound represented by formula (IV). Preferably, the third component is one selected from the group consisting of the compound represented by formula (VI), the compound represented by formula (VII), the compound represented by formula (VIII-1), the compound represented by formula (VIII-2), the compound represented by formula (IX), the compound represented by formula (X), the compound represented by formula (XI), and the compound represented by formula (XII), the content of the first component is 0.05% by mass to 0.5% by mass or less with respect to the total amount of the non-aqueous electrolyte (when the total amount of the non-aqueous electrolyte is 100% by mass), the content of the second component is 0.05% by mass to 0.5% by mass or less with respect to the total amount of the non-aqueous electrolyte (when the total amount of the non-aqueous electrolyte is 100% by mass), and the content of the third component is 0.05% by mass to 0.5% by mass or less with respect to the total amount of the non-aqueous electrolyte (when the total amount of the non-aqueous electrolyte is 100% by mass). As a result, non-aqueous electrolytes can more effectively suppress the increase in resistance after high-temperature storage of non-aqueous electrolyte secondary batteries.

[0171] The non-aqueous electrolyte preferably contains the first component and satisfies either condition (a3) ​​or condition (b3). Condition (a3): The non-aqueous electrolyte further contains the second component, the second component comprises a compound represented by formula (II) and a compound represented by formula (IV) or a compound represented by formula (V), the content of the first component is 0.05% by mass to 0.5% by mass or less with respect to the total amount of the non-aqueous electrolyte (when the total amount of the non-aqueous electrolyte is 100% by mass), and the content of the second component is 0.05% by mass to 0.5% by mass or less with respect to the total amount of the non-aqueous electrolyte (when the total amount of the non-aqueous electrolyte is 100% by mass). Condition (b3): ​​The non-aqueous electrolyte further contains the second component and the third component, the second component comprises a compound represented by formula (II), Preferably, the third component is one selected from the group consisting of the compound represented by formula (VI), the compound represented by formula (VII), the compound represented by formula (VIII-1), the compound represented by formula (VIII-2), the compound represented by formula (IX), the compound represented by formula (X), the compound represented by formula (XI), and the compound represented by formula (XII), the content of the first component is 0.05% by mass to 0.5% by mass or less with respect to the total amount of the non-aqueous electrolyte (when the total amount of the non-aqueous electrolyte is 100% by mass), the content of the second component is 0.05% by mass to 0.5% by mass or less with respect to the total amount of the non-aqueous electrolyte (when the total amount of the non-aqueous electrolyte is 100% by mass), and the content of the third component is 0.05% by mass to 0.5% by mass or less with respect to the total amount of the non-aqueous electrolyte (when the total amount of the non-aqueous electrolyte is 100% by mass). As a result, non-aqueous electrolytes can more effectively suppress the increase in resistance after high-temperature storage of non-aqueous electrolyte secondary batteries.

[0172] (1.5) Non-aqueous solvents Non-aqueous electrolytes generally contain a non-aqueous solvent. Various known non-aqueous solvents can be appropriately selected. There may be only one type of non-aqueous solvent, or there may be two or more types.

[0173] Examples of non-aqueous solvents include cyclic carbonates, fluorinated cyclic carbonates, linear carbonates, fluorinated linear carbonates, aliphatic carboxylic acid esters, fluorinated aliphatic carboxylic acid esters, γ-lactones, fluorinated γ-lactones, cyclic ethers, fluorinated cyclic ethers, linear ethers, fluorinated linear ethers, nitriles, amides, lactams, nitromethane, nitroethane, sulfolanes, trimethyl phosphate, dimethyl sulfoxide, and dimethyl sulfoxide phosphate. Examples of cyclic carbonates include ethylene carbonate (EC), propylene carbonate (PC), and butylene carbonate (BC). Examples of fluorinated cyclic carbonates include fluoroethylene carbonate (FEC). Examples of linear carbonates include dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), methyl propyl carbonate (MPC), ethyl propyl carbonate (EPC), and dipropyl carbonate (DPC). Examples of aliphatic carboxylic acid esters include methyl formate, methyl acetate, methyl propionate, methyl butyrate, methyl isobutyrate, methyl trimethylbutyrate, ethyl formate, ethyl acetate, ethyl propionate, ethyl butyrate, ethyl isobutyrate, and ethyl trimethylbutyrate. Examples of γ-lactones include γ-butyrolactone and γ-valerolactone. Examples of cyclic ethers include tetrahydrofuran, 2-methyltetrahydrofuran, tetrahydropyran, 1,3-dioxolane, 4-methyl-1,3-dioxolane, 1,3-dioxane, and 1,4-dioxane. Examples of linear ethers include 1,2-ethoxyethane (DEE), ethoxymethoxyethane (EME), diethyl ether, 1,2-dimethoxyethane, and 1,2-dibutoxyethane. Examples of nitriles include acetonitrile, glutalonitrile, adiponitrile, methoxyacetonitrile, and 3-methoxypropionitrile. Examples of amides include N,N-dimethylformamide.Examples of lactam compounds include N-methylpyrrolidinone, N-methyloxazolidinone, and N,N'-dimethylimidazolidinone.

[0174] The non-aqueous solvent preferably contains at least one selected from the group consisting of cyclic carbonates, fluorine-containing cyclic carbonates, linear carbonates, and fluorine-containing linear carbonates. In this case, the total proportion of cyclic carbonates, fluorine-containing cyclic carbonates, linear carbonates, and fluorine-containing linear carbonates is preferably 50% to 100% by mass, more preferably 60% to 100% by mass, and even more preferably 80% to 100% by mass, based on the total amount of the non-aqueous solvent.

[0175] The non-aqueous solvent preferably contains at least one selected from the group consisting of cyclic carbonates and linear carbonates. In this case, the total proportion of cyclic carbonates and linear carbonates is preferably 50% to 100% by mass, more preferably 60% to 100% by mass, and even more preferably 80% to 100% by mass, based on the total amount of the non-aqueous solvent.

[0176] The non-aqueous solvent content is preferably 99% by mass, more preferably 97% by mass, and even more preferably 90% by mass, relative to the total amount of the non-aqueous electrolyte. The non-aqueous solvent content is preferably 60% by mass or more, more preferably 70% by mass or more, relative to the total amount of the non-aqueous electrolyte.

[0177] The intrinsic viscosity of the non-aqueous solvent is preferably 10.0 mPa·s or less at 25°C, from the viewpoint of further improving the dissociation of the electrolyte and the mobility of ions.

[0178] (1.6) Non-aqueous electrolytes generally contain electrolytes.

[0179] The electrolyte preferably contains at least one of a lithium salt containing fluorine (hereinafter sometimes referred to as "fluorinated lithium salt") and a lithium salt that does not contain fluorine.

[0180] Examples of fluorinated lithium salts include inorganic acid anionic salts and organic acid anionic salts. Examples of inorganic acid anionic salts include lithium hexafluoride phosphate (LiPF). ６ ), lithium tetrafluoroborate (LiBF ４ ), lithium hexafluoride arsenate (LiAsF ６ ), and lithium tantalate hexafluoride (LiTaF ６ Examples of organic acid anionic salts include lithium bis(pentafluoroethanesulfonyl)imide (Li(C)). ２ F ５ SO ２ ) ２ Examples include N). Among them, lithium hexafluoride phosphate (LiPF) is an example of a fluorinated lithium salt. ６ ) is even more preferable.

[0181] Lithium salts that do not contain fluorine include lithium perchlorate (LiClO2). ４ ), lithium aluminum tetrachloride (LiAlCl ４ ), and lithium decachlorodecaborate (Li ２ B １０ Cl １０ ) are some examples.

[0182] When the electrolyte contains a fluorinated lithium salt, the content of the fluorinated lithium salt is preferably 50% to 100% by mass, more preferably 60% to 100% by mass, and even more preferably 80% to 100% by mass, relative to the total amount of the electrolyte. ６ If it contains lithium hexafluoride phosphate (LiPF), ６ The content of ) is preferably 50% to 100% by mass, more preferably 60% to 100% by mass, and even more preferably 80% to 100% by mass, relative to the total amount of electrolyte.

[0183] When the non-aqueous electrolyte contains an electrolyte, the concentration of the electrolyte in the non-aqueous electrolyte is preferably 0.1 mol / L to 3 mol / L, more preferably 0.5 mol / L to 2 mol / L.

[0184] The non-aqueous electrolyte is lithium hexafluoride phosphate (LiPF). ６ ) If it contains lithium hexafluoride phosphate (LiPF) in a non-aqueous electrolyte, ６ The concentration of the substance is preferably 0.1 mol / L to 3 mol / L, more preferably 0.5 mol / L to 2 mol / L.

[0185] (2) Non-aqueous electrolyte B Another embodiment of the present disclosure of a non-aqueous electrolyte (hereinafter sometimes abbreviated as "non-aqueous electrolyte B") includes one or more compounds selected from the group consisting of a compound represented by the following formula (I-1) (i.e., compound (I-1)) and a compound represented by the following formula (I-2) (i.e., compound (I-2)), and one or more compounds selected from the group consisting of a compound represented by the following formula (IV) (i.e., compound (IV)).

[0186]

[0187] In formula (I-1), R １１ and R １２ The substituents are a halogen group, an oxa group (-O-), a carbonyl group (>C=O), and a sulfonyl group (>S(=O)). ２ This represents a divalent hydrocarbon group having 1 to 6 carbon atoms, which may contain at least one functional group selected from the group consisting of ). In formula (I-2), R １１ The substituents are a halogen group, an oxa group (-O-), a carbonyl group (>C=O), and a sulfonyl group (>S(=O)). ２ Represents a divalent hydrocarbon group having 1 to 6 carbon atoms, which may contain at least one functional group selected from the group consisting of ). １３ These can be independently substituted with a halogen group, a cyano group (-CN), an oxa group (-O-), a carbonyl group (>C=O), and a sulfonyl group (>S(=O)). ２ This represents a hydrocarbon group having 1 to 12 carbon atoms, which may contain at least one functional group selected from the group consisting of ).

[0188]

[0189] In formula (IV), R ４１ is a methylene group (-CH ２ -), ethylene group (-CH２ CH ２ -), or n-propylene group (-CH ２ CH ２ CH ２ Represents (-). ４２ Each of these independently represents a hydrocarbon group having 1 to 12 carbon atoms, which may contain at least one functional group selected from the group consisting of a halogen group and an oxa group (-O-) as a substituent. ４１ is a methylene group (-CH ２ When h is -, it represents 1 or 2. ４１ is an ethylene group (-CH ２ CH ２ When h is -, h represents an integer from 1 to 4. ４１ is an n-propylene group (-CH ２ CH ２ CH ２ When h is -, it represents an integer from 1 to 6.

[0190] The Disclosers have diligently conducted studies to solve the aforementioned problems. As a result, the Disclosers have found that by using a non-aqueous electrolyte containing at least one compound selected from compound (I-1) and compound (I-2) and compound (IV), the increase in resistance of a non-aqueous electrolyte secondary battery after high-temperature storage can be effectively suppressed.

[0191] (2.1) Compound (I-1) and Compound (I-2) Compound (I-1) is the same as the one exemplified as "Compound (I-1)" of non-aqueous electrolyte A. Compound (I-2) is the same as the one exemplified as "Compound (I-2)" of non-aqueous electrolyte A.

[0192] The content of compound (I-1) and compound (I-2) in non-aqueous electrolyte B is usually 0.001% to 5% by mass relative to the total amount of the non-aqueous electrolyte (when the total amount of the non-aqueous electrolyte is considered as 100% by mass). The content of compound (I-1) and compound (I-2) may be 0.01% or more by mass, 0.1% or more by mass, 0.5% or more by mass, or 0.8% or more by mass. The content of compound (I-1) and compound (I-2) may be 4.0% or less by mass, 3.0% or less by mass, 2.0% or less by mass, 1.5% or less by mass, 0.5% or less by mass, or 0.3% or less by mass. When the content of compound (I-1) and compound (I-2) is within the above range, the increase in resistance after high-temperature storage can be suppressed.

[0193] (2.2) Compound (IV) Compound (IV) is the same as the one exemplified as "Compound (IV)" in non-aqueous electrolyte A.

[0194] The content of compound (IV-1) in non-aqueous electrolyte B is usually 0.001% to 5% by mass relative to the total amount of the non-aqueous electrolyte (when the total amount of the non-aqueous electrolyte is considered as 100% by mass). The content of compound (IV-1) may be 0.01% or more by mass, 0.1% or more by mass, 0.3% or more by mass, 0.5% or more by mass, or 0.8% or more by mass. The content of compound (IV-1) may be 4.0% or less by mass, 3.0% or less by mass, 2.0% or less by mass, 1.5% or less by mass, 0.7% or less by mass, 0.5% or less by mass, or 0.3% or less by mass. When the content of compound (IV-1) is within the above range, the increase in resistance after high-temperature storage can be suppressed.

[0195] (2.3) Non-aqueous solvents Non-aqueous electrolytes generally contain a non-aqueous solvent. Various known non-aqueous solvents can be appropriately selected. There may be only one type of non-aqueous solvent, or there may be two or more types. The non-aqueous solvent is the same as that exemplified as the non-aqueous solvent in non-aqueous electrolyte A.

[0196] (2.4) Non-aqueous electrolytes generally contain electrolytes. The electrolyte is the same as that exemplified as the electrolyte in non-aqueous electrolyte A.

[0197] (3) Non-aqueous electrolyte secondary battery The non-aqueous electrolyte secondary battery of the present disclosure comprises a positive electrode, a negative electrode, the non-aqueous electrolyte of the present disclosure, and a separator.

[0198] Because the non-aqueous electrolyte secondary battery of this disclosure has the above configuration, the increase in resistance after high-temperature storage can be suppressed.

[0199] (3.1) Positive electrode The positive electrode can be manufactured by applying a slurry to a current collector, drying and compressing it to form a positive electrode composite layer on the current collector. The slurry comprises a positive electrode active material, a binder, and a solvent, and optionally further comprises a conductive additive and a thickener dispersed in the solvent.

[0200] As the positive electrode active material, MoS ２ TiS ２ MnO ２ , V ２ O ５ Transition metal oxides or transition metal sulfides such as LiCoO ２ LiMnO ２ LiMn ２ O ４ LiNiO ２ LiNi Ｘ Co （１－Ｘ） O ２ (0<X<1), LiNi ｘ Co ｙ Mn ｚ O ２ (x, y, and z are each independently greater than 0 and less than 1.00, and the sum of x, y, and z is between 0.99 and 1.00.) (So-called "NCM"; e.g., LiNi) ０．３３ Co ０．３３ Mn ０．３３ O ２ LiNi ０．５ Co ０．３ Mn ０．２ O ２ LiNi ０．５ Co ０．２ Mn ０．３ O ２ LiNi ０．６ Co ０．２ Mn ０．２ O ２ LiNi ０．８ Co ０．１ Mn ０．１ O ２Composite oxides consisting of lithium and transition metals such as Li ｔ Ni １－ｘ－ｙ Co ｘ Al ｙ O ２ (t is between 0.95 and 1.15, x is between 0 and 0.3, y is between 0.1 and 0.2, and the sum of x and y is less than 0.5.) (So-called "NCA"; for example, LiNi ０．８ Co ０．１５ Al ０．０５ O ２ Composite oxides consisting of lithium, transition metals and typical metals such as ); conductive polymer materials such as polyaniline, polythiophene, polypyrrole, polyacetylene, polyacene, dimercaptothiadiazole, and polyaniline composites; and lithium iron phosphate (LiFePO) ４ ), Lithium manganese phosphate (LiMnPO ４ ), Lithium iron manganese phosphate (LiMn ｘ Fe １－ｘ PO ４ ; 0 < x < 1), LiCoPO2 ４ ), lithium nickel phosphate (LiNiPO ４ Examples include lithium metal phosphate such as ) and others.

[0201] Examples of binders for the positive electrode include polyvinylidene fluoride. Examples of conductive additives for the positive electrode include carbon black (e.g., acetylene black), amorphous whiskers, and graphite. Examples of thickeners for the positive electrode include carboxymethylcellulose. Examples of solvents for the slurry used to form the positive electrode include organic solvents such as N-methylpyrrolidone.

[0202] The total content of the positive electrode active material is typically 70% to 97% by mass, preferably 75% or more by mass, and preferably 95% or less by mass, when the total amount of the positive electrode composite layer is considered as 100% by mass.

[0203] Examples of materials for the positive electrode current collector include aluminum, aluminum alloy, stainless steel, nickel, titanium, tantalum, carbon cloth, and carbon paper.

[0204] (3.2) The negative electrode can be manufactured by applying a slurry to a current collector, drying it, and compressing it to form a negative electrode composite layer on the current collector. The slurry comprises a negative electrode active material, a binder, and a solvent, and optionally further comprises a conductive additive and a thickener dispersed in the solvent.

[0205] (3.2.1) Negative electrode composite layer (3.2.1.1) Negative electrode active material The element or compound that becomes the negative electrode active material may be any of the following (i) to (iii): (i) Elemental carbon and carbon compounds that can be doped / dedoped with lithium ions (ii) Metals and alloys that can be alloyed with lithium (iii) Compounds that can be doped / dedoped with lithium ions (e.g. oxides, nitrides, and carbides) If the negative electrode active material is elemental silicon, the negative electrode active material may be in the form of particulate (powder) elements or compounds. The negative electrode active material may be used alone or mixed with two or more other elements.

[0206] The negative electrode active material preferably includes elemental carbon particles and at least one selected from the group consisting of elemental silicon particles, silicon oxide particles, and silicon carbide particles. Examples of elemental carbon particles include graphite (natural graphite, artificial graphite) particles, carbon black particles, activated carbon particles, and amorphous carbon particles. Examples of artificial graphite include graphitized mesocarbon microbeads (MCMB) and graphitized mesophase pitch carbon fibers (MCF). Examples of amorphous carbon materials include hard carbon, coke, MCMB and MCF fired at 1500°C or below.

[0207] When the negative electrode active material is in particulate (powder) form, the detailed shape of the negative electrode active material can be fibrous, spherical, potato-shaped, or flake-shaped.

[0208] The median diameter (D) of a single carbon particle ５０ The particle size is usually 1 μm to 30 μm, preferably 10 μm or more, more preferably 15 μm or more, preferably 25 μm or less, and more preferably 20 μm or less.

[0209] The BET specific surface area of ​​elemental carbon particles is typically 1.0 m². ２ / g to 5.0m２ The value is / g, preferably 2.0m ２ / g or more, more preferably 3.0m ２ The amount is 1 / g or more, preferably 4.5m ２ / g or less, more preferably 4.0m ２ It is less than or equal to / g.

[0210] Silicon dioxide is SiO ｘ It is expressed as follows. x (i.e., the oxygen atom content in silicon dioxide) is not particularly limited. x is usually 0 ≤ x < 2, preferably 0.2 or more, more preferably 0.4 or more, even more preferably 0.6 or more, preferably 1.8 or less, more preferably 1.6 or less, and even more preferably 1.4 or less.

[0211] The median diameter (D) of elemental silicon particles, silicon oxide particles, or silicon carbide particles. ５０ The particle size is usually 0.5 μm to 20 μm, preferably 1.0 μm or more, more preferably 3.0 μm or more, preferably 15 μm or less, and more preferably 10 μm or less.

[0212] The BET specific surface area of ​​elemental silicon particles, silicon oxide particles, or silicon carbide particles is typically 1.0 m². ２ / g to 5.0m ２ The value is / g, preferably 1.5m ２ / g or more, more preferably 2.0m ２ The amount is 1 / g or more, preferably 4.5m ２ / g or less, more preferably 4.0m ２ It is less than or equal to / g.

[0213] When the negative electrode active material includes elemental carbon particles and at least one selected from the group consisting of elemental silicon particles, silicon oxide particles, and silicon carbide particles, the total mass of elemental silicon particles, silicon oxide particles, and silicon carbide particles in the negative electrode active material is usually 1% to 20% by mass, preferably 3% or more by mass, more preferably 5% or more by mass, preferably 18% or less by mass, and more preferably 15% or less by mass, when the total mass of the entire negative electrode active material is taken as 100% by mass.

[0214] When the negative electrode active material includes elemental carbon particles and at least one selected from the group consisting of elemental silicon particles, silicon oxide particles, and silicon carbide particles, the total mass of elemental carbon particles in the negative electrode active material is usually 70% to 99% by mass, preferably 80% or more by mass, preferably 95% or less by mass, and more preferably 90% or less by mass, when the total mass of the entire negative electrode active material is taken as 100% by mass. When the total mass of elemental silicon particles, etc., is within the above range, it becomes easier to ensure a balance between the energy density and capacity retention rate of the non-aqueous electrolyte secondary battery.

[0215] The total content of the negative electrode active material is typically 70% to 99.5% by mass, preferably 75% or more by mass, and preferably 99% or less by mass, when the total amount of the negative electrode composite layer is considered as 100% by mass.

[0216] (3.2.1.2) Examples of binders for the negative electrode include styrene-butadiene rubber (SBR). The total content of the binder is usually 0.1% to 5% by mass, preferably 0.5% or more by mass, more preferably 1.0% or more by mass, preferably 3% or less by mass, and more preferably 2% or less by mass, when the total amount of the negative electrode composite layer is considered as 100% by mass.

[0217] (3.2.1.3) The conductive additive negative electrode composite layer preferably further contains a conductive additive. Examples of conductive additives for the negative electrode include carbon black (e.g., acetylene black), carbon nanotubes, amorphous whiskers, and graphite.

[0218] The total content of the conductive additive is typically 0.01% to 3% by mass, preferably 0.05% or more by mass, more preferably 0.1% or more by mass, preferably 2% or less by mass, and more preferably 1% or less by mass, when the total amount of the negative electrode composite layer is considered as 100% by mass.

[0219] (3.2.1.4) The anode composite layer preferably further contains a thickening agent. The inclusion of a thickening agent in the slurry makes it easier to adjust the viscosity of the slurry and improves productivity. Examples of thickening agents for the anode composite layer include cellulose derivatives such as carboxymethylcellulose (CMC), carboxyethylcellulose, and hydroxyethylcellulose, polyoxyethylene and its modified forms, polyvinyl alcohol and its modified forms, and polysaccharides.

[0220] The total content of the thickening agent is typically 0.1% to 5% by mass, preferably 0.5% or more by mass, more preferably 1.0% or more by mass, preferably 3% or less by mass, and more preferably 2% or less by mass, when the total amount of the negative electrode composite layer is considered as 100% by mass.

[0221] (3.2.1.5) The solvent slurry may contain a solvent. Examples of solvents include water, acetonitrile, N-methylpyrrolidone, acetylpyridine, cyclopentanone, dimethylformamide, dimethyl sulfoxide, methylformamide, methyl ethyl ketone, furfural, and ethylenediamine. The solvent may be a mixed solvent obtained by mixing the aforementioned solvents.

[0222] (3.2.2) Examples of materials for the current collector of the negative electrode include copper, nickel, stainless steel, and nickel-plated steel.

[0223] (3.3) Separator An example of a separator is a porous resin plate. Examples of materials for the porous resin plate include resin and nonwoven fabric containing this resin. Examples of resins include polyethylene (PE), polypropylene (PP), polymethylpentene (PMP), polyester, cellulose, and polyamide. Among these, the separator is preferably a porous resin sheet with a single-layer or multi-layer structure. The material of the porous resin sheet is mainly at least one polyolefin resin. The thickness of the separator is preferably 5 μm to 30 μm. The separator is preferably placed between the positive electrode and the negative electrode.

[0224] (3.4) Case The shape of the case is not particularly limited and can be appropriately selected depending on the application of the non-aqueous electrolyte secondary battery of this disclosure. Examples of cases include cases including a laminate film, and cases consisting of a battery can and a battery can lid.

[0225] (4) Specific Examples of Non-Aqueous Electrolyte Secondary Batteries (4.1) Stacked Type Figure 1 is a schematic cross-sectional view showing a stacked type non-aqueous electrolyte secondary battery, which is an example of a non-aqueous electrolyte secondary battery of the present disclosure.

[0226] As shown in Figure 1, the non-aqueous electrolyte secondary battery 1 is a stacked battery precursor. More specifically, in the non-aqueous electrolyte secondary battery 1, the battery element 10 is sealed inside a case 30. The case 30 is made of laminate film. The battery element 10 is fitted with a positive electrode lead 21 and a negative electrode lead 22. The positive electrode lead 21 and the negative electrode lead 22 are led out in opposite directions from the inside to the outside of the case 30.

[0227] As shown in Figure 1, the battery element 10 is made up of a stack of a positive electrode 11, a separator 13, and a negative electrode 12. The positive electrode 11 has a positive electrode composite layer 11B formed on both main surfaces of the positive electrode current collector 11A. The negative electrode 12 has a negative electrode composite layer 12B formed on both main surfaces of the negative electrode current collector 12A. The positive electrode composite layer 11B formed on one main surface of the positive electrode current collector 11A of the positive electrode 11 and the negative electrode composite layer 12B formed on one main surface of the negative electrode current collector 12A of the negative electrode 12 adjacent to the positive electrode 11 face each other via the separator 13.

[0228] The non-aqueous electrolyte of this disclosure is injected into the case 30 of the non-aqueous electrolyte secondary battery 1. The non-aqueous electrolyte of this disclosure permeates the positive electrode composite layer 11B, the separator 13, and the negative electrode composite layer 12B. In the non-aqueous electrolyte secondary battery 1, a single cell layer 14 is formed by adjacent positive electrode composite layers 11B, the separator 13, and the negative electrode composite layer 12B. The positive electrode may have a positive electrode composite layer formed on one side of the current collector. The negative electrode may have a negative electrode composite layer formed on one side of the current collector.

[0229] The non-aqueous electrolyte secondary battery 1 is a stacked type non-aqueous electrolyte secondary battery, but the non-aqueous electrolyte secondary battery of this disclosure is not limited to this, and may be, for example, a wound type non-aqueous electrolyte secondary battery. The wound type non-aqueous electrolyte secondary battery is formed by stacking a positive electrode, a separator, a negative electrode, and a separator in this order and winding them in layers. The wound type non-aqueous electrolyte secondary battery includes cylindrical non-aqueous electrolyte secondary batteries and prismatic non-aqueous electrolyte secondary batteries.

[0230] As shown in Figure 1, in the non-aqueous electrolyte secondary battery 1, the directions in which the positive electrode lead and the negative electrode lead protrude from the inside to the outside of the case 30 are opposite to the case 30, but the disclosure is not limited thereto. For example, the way in which the positive electrode lead and the negative electrode lead protrude from the inside to the outside of the case 30 is the same direction with respect to the case 30.

[0231] The non-aqueous electrolyte secondary battery 1 is obtained by charging and discharging a non-aqueous electrolyte secondary battery precursor. The non-aqueous electrolyte secondary battery precursor is the same as the non-aqueous electrolyte secondary battery 1 except that it has not been charged and discharged (i.e., no SEI (Solid Electrolyte Interphase) film is attached to the surface of the positive electrode and the surface of the negative electrode).

[0232] (4.2) Coin-type Figure 2 is a schematic cross-sectional view showing a coin-type non-aqueous electrolyte secondary battery, which is another example of a non-aqueous electrolyte secondary battery of the present disclosure.

[0233] In the coin-type non-aqueous electrolyte secondary battery shown in Figure 2, a disc-shaped negative electrode 42, a separator 45 into which the non-aqueous electrolyte is injected, a disc-shaped positive electrode 41, and, if necessary, spacer plates 47 and 48 made of stainless steel or aluminum are stacked in this order and housed between the positive electrode can 43 (hereinafter also referred to as the "battery can") and the sealing plate 44 (hereinafter also referred to as the "battery can lid"). The positive electrode can 43 and the sealing plate 44 are crimped and sealed via a gasket 46. In this example, the non-aqueous electrolyte of this disclosure is used as the non-aqueous electrolyte injected into the separator 45.

[0234] (5) Non-aqueous electrolyte secondary battery and method for manufacturing the same The method for manufacturing the non-aqueous electrolyte secondary battery of the present disclosure includes the steps of preparing the non-aqueous electrolyte secondary battery precursor of the present disclosure described above (hereinafter also referred to as the "preparation step") and the steps of charging and discharging the non-aqueous electrolyte secondary battery precursor. The non-aqueous electrolyte secondary battery of the present disclosure is a non-aqueous electrolyte secondary battery obtained by charging and discharging the non-aqueous electrolyte secondary battery precursor of the present disclosure described above.

[0235] The "non-aqueous electrolyte secondary battery precursor" is the same as a non-aqueous electrolyte secondary battery, except that it has not undergone charging and discharging (i.e., no SEI (Solid Electrolyte Interphase) film is attached to the surface of the positive electrode and the surface of the negative electrode).

[0236] According to the non-aqueous electrolyte secondary battery and its manufacturing method, the rate of resistance increase (at 25°C) during high-temperature storage of the non-aqueous electrolyte secondary battery can be reduced.

[0237] The preparation step may simply be a step of preparing a pre-manufactured non-aqueous electrolyte secondary battery precursor of the present disclosure for use in the charging and discharging process, or it may be a step of manufacturing the non-aqueous electrolyte secondary battery precursor of the present disclosure.

[0238] In the charging and discharging process, the charging and discharging of the non-aqueous electrolyte secondary battery precursor can be carried out according to known methods. In this process, the charging and discharging cycle may be repeated multiple times for the non-aqueous electrolyte secondary battery precursor. As described above, this charging and discharging preferably forms an SEI film on at least one surface of the positive electrode (particularly the positive electrode active material) and the negative electrode (particularly the negative electrode active material) of the non-aqueous electrolyte secondary battery precursor.

[0239] The charging and discharging process preferably involves performing a combination of charging and discharging one or more times on the non-aqueous electrolyte secondary battery precursor in an environment of 25°C to 70°C.

[0240] The following are examples of the embodiments of this disclosure, but this disclosure is not limited to these embodiments. Hereinafter, "%" refers to "mass%" unless otherwise specified.

[0241] [Example 1-1] <Preparation of Non-Aqueous Electrolyte> Ethylene carbonate (hereinafter sometimes abbreviated as "EC"), dimethyl carbonate (hereinafter sometimes abbreviated as "DMC"), and ethyl methyl carbonate (hereinafter sometimes abbreviated as "EMC") were mixed. The volume ratio (EC:DMC:EMC) was 30:35:35. A mixed solvent was obtained as a non-aqueous solvent. LiPF was added to the obtained mixed solvent as an electrolyte. ６ The substances were dissolved so that the final concentration in the non-aqueous electrolyte was 1 mol / L, thereby obtaining an electrolyte (hereinafter sometimes abbreviated as "basic electrolyte"). To the obtained basic electrolyte, methylene methane disulfonate (MMDS) represented by the following formula (I-1-1) and lithium trifluoromethanesulfonate (LiSO4) represented by the following formula (II-1) were added. ３ CF ３ A non-aqueous electrolyte was obtained by adding a sulfate ester represented by the following formula (IV-1). The amount of each additive added was adjusted so that its content relative to the total amount of the non-aqueous electrolyte obtained (value when the total amount of the non-aqueous electrolyte is considered as 100% by mass) was as shown in Table 1 (mass%).

[0242]

[0243] <Fabrication of the positive electrode> Li(Ni) as the positive electrode active material ０．５ Co ０．２ Mn ０．３ O ２ A mixture was obtained by mixing (94% by mass) of a material, carbon black (3% by mass) as a conductive additive, and polyvinylidene fluoride (PVdF) (3% by mass) as a binder. The obtained mixture was dispersed in N-methylpyrrolidone solvent to obtain a positive electrode mixture slurry. A 20 μm thick aluminum foil was prepared as the positive electrode current collector. The obtained positive electrode mixture slurry was applied to the aluminum foil, and the resulting coating was dried to obtain coated aluminum foil. Subsequently, the coated aluminum foil was rolled in a press to obtain a sheet-like positive electrode. The positive electrode consists of a positive electrode current collector and a positive electrode mixture layer.

[0244] <Preparation of the negative electrode> A negative electrode slurry was obtained by mixing graphite (96% by mass) as the negative electrode active material, carbon black (1% by mass) as a conductive additive, carboxymethylcellulose sodium dispersed in pure water (1% by mass in solids) as a thickener, and styrene-butadiene rubber (SBR) dispersed in pure water (2% by mass in solids) as a binder. A copper foil with a thickness of 10 μm was prepared as the negative electrode current collector. The obtained negative electrode slurry was applied to the copper foil, and the resulting coating was dried to obtain a coated copper foil. Subsequently, the coated copper foil was rolled in a press to obtain a sheet-like negative electrode. The negative electrode consists of a negative electrode current collector and a negative electrode slurry layer.

[0245] <Preparation of the separator> A porous polyethylene film was prepared as the separator.

[0246] <Preparation of a non-aqueous electrolyte secondary battery precursor> The negative electrode was punched out in a diameter of 14 mm, the positive electrode in a diameter of 13 mm, and the separator in a diameter of 17 mm, each in a disc shape. This yielded a coin-shaped negative electrode, a coin-shaped positive electrode, and a coin-shaped separator. The obtained coin-shaped negative electrode, coin-shaped separator, and coin-shaped positive electrode were stacked in this order inside a stainless steel battery case (size: 2032). Next, 20 μL of non-aqueous electrolyte was poured into the battery case, immersing the separator, positive electrode, and negative electrode in the non-aqueous electrolyte. Then, an aluminum plate (thickness 1.2 mm, diameter 16 mm) and a spring were placed on the positive electrode, and the battery was sealed by crimping the battery case lid via a polypropylene gasket. As a result, a coin-shaped non-aqueous electrolyte secondary battery precursor (i.e., a non-aqueous electrolyte secondary battery before charging and discharging) having the configuration shown in Figure 2 was obtained. The size of the non-aqueous electrolyte secondary battery precursor was 20 mm in diameter and 3.2 mm in height.

[0247] <Preparation of Non-Aqueous Electrolyte Secondary Battery> The non-aqueous electrolyte secondary battery precursor was subjected to the following processes in order: charging from 1.5V to 4.2V, holding for 5 to 50 hours, charging to 4.2V, and discharging to 2.5V, all within a temperature range of 25°C to 70°C, to obtain a non-aqueous electrolyte secondary battery.

[0248] <Evaluation of Initial Resistance (-10°C)> A non-aqueous electrolyte secondary battery was charged to 3.7V, then cooled to -10°C in a constant temperature bath, and discharged. The DC resistance [Ω] as the initial resistance (-10°C) was measured based on the voltage drop (= voltage before discharge - voltage 10 seconds after discharge) and the current value (i.e., the current value corresponding to the discharge rates of 0.1C to 0.6C) for each discharge rate of 0.1C to 0.6C during a "CC10s discharge".

[0249] <Evaluation of Resistance After High-Temperature Storage (-10°C)> Next, the non-aqueous electrolyte secondary battery, after the initial resistance measurement, was charged to 4.2V, and the charged non-aqueous electrolyte secondary battery was stored in a constant temperature bath at 60°C for 14 days (hereinafter, this may be abbreviated as "high-temperature storage"). Next, the resistance (-10°C) of the non-aqueous electrolyte secondary battery after high-temperature storage was measured in the same manner as the initial resistance (-10°C). The same procedure was followed for the reference example described later, and the resistance (-10°C) of the non-aqueous electrolyte secondary battery after high-temperature storage was measured. The relative value of the resistance (-10°C) of the non-aqueous electrolyte secondary battery in Example 1-1 after high-temperature storage was defined as "Resistance after High-Temperature Storage (-10°C) (Relative Value)" when the resistance (-10°C) of the non-aqueous electrolyte secondary battery in the reference example after high-temperature storage was set to 100. The obtained "Resistance after High-Temperature Storage (-10°C) (Relative Value)" is shown in Tables 1 to 4.

[0250] [Example] Methylene methane disulfonate (MMDS) represented by formula (I-1-1) and lithium trifluoromethanesulfonate (LiSO4) represented by formula (II-1). ３ CF ３ A non-aqueous electrolyte was prepared by the same procedure as described in Example 1-1, except that the sulfate ester represented by formula (IV-1) was not added, and a non-aqueous electrolyte secondary battery was prepared. Furthermore, the initial resistance (-10°C) and the resistance of the non-aqueous electrolyte secondary battery after high-temperature storage (-10°C) were measured by the same procedure as described in Example 1. The resistance of the non-aqueous electrolyte secondary battery after high-temperature storage (-10°C) in the reference example was used as the reference value for "resistance after high-temperature storage (-10°C) (relative value)" in Example 1-1, etc.

[0251] [Examples 1-2 to 1-39, Comparative Examples 1-1 to 1-4] The same procedure as in Example 1-1 was followed, except that the types and contents of the components used in the preparation of the non-aqueous electrolyte were changed as shown in Tables 1 to 4. The results are shown in Tables 1 to 4. The components shown in Tables 1 to 4 are methylene methane disulfonate (MMDS) represented by the following formula (I-1-1), and lithium trifluoromethanesulfonate (LiSO4) represented by the following formula (II-1). ３ CF ３ ), 1,3,2-dioxathiolane 2,2-dioxide (DTD) represented by the following formula (III-1), sulfate ester represented by the following formula (IV-1), sulfate ester represented by the following formula (V-1), 1,3-propanesultone (PS) represented by the following formula (VI-1), 1-propene-1,3-sultone (PRS) represented by the following formula (VI-5), lithium bis(oxalato)borate (LiBOB) represented by the following formula (VII-1), lithium difluorooxalatoborate (LiDFOB) represented by the following formula (VII-2), lithium difluorophosphate (LiPO) represented by the following formula (VIII-1-1) ２ F ２ ), lithium fluorosulfonate (LiSO4), represented by the following formula (IX-1) ３ F) Lithium bis(fluorosulfonyl)imide (LiFSI) represented by the following formula (X-1), vinylene carbonate (VC) represented by the following formula (XI-1), and N,N'-di-i-propylcarbodiimide (DIC) represented by the following formula (XII-1).

[0252]

[0253]

[0254]

[0255]

[0256]

[0257] In Tables 1 to 4, "battery" refers to a non-aqueous electrolyte secondary battery. "Resistance (-10°C)" refers to the resistance after high-temperature storage (-10°C) (relative value).

[0258] [Examples 2-1, 2-2, Comparative Example 2-1, Comparative Example 2-2] The same procedure as in Example 1-1 was followed, except that the types and contents of the components used in the preparation of the non-aqueous electrolyte were changed as shown in Table 5. The results are shown in Table 5. The components shown in Table 5 are methylene methane disulfonate (MMDS) represented by the following formula (I-1-1), 1,3,2-dioxathiolane 2,2-dioxide (DTD) represented by the following formula (III-1), sulfate ester represented by the following formula (IV-1), and sulfate ester represented by the following formula (V-1).

[0259]

[0260]

[0261] In Table 5, "battery" refers to a non-aqueous electrolyte secondary battery. "Resistance (-10°C)" refers to the resistance after high-temperature storage (-10°C) (relative value).

[0262] As is clear from Tables 1 to 4, by using a non-aqueous electrolyte containing a first component and two or more second components (i.e., satisfying condition 1), or a non-aqueous electrolyte containing a first component, a second component, and a third component (i.e., satisfying condition 2), the increase in resistance of a non-aqueous electrolyte secondary battery after high-temperature storage can be suppressed. As is clear from Table 5, by using a non-aqueous electrolyte containing a compound represented by formula (I-1) and a compound represented by formula (IV), the increase in resistance of a non-aqueous electrolyte secondary battery after high-temperature storage can be suppressed.

[0263] The disclosure of Japanese Patent Application No. 2025-050690, filed on 25 March 2025, is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards described herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard were specifically and individually noted to be incorporated by reference.

Claims

1. A non-aqueous electrolyte comprising a first component, wherein the first component represents at least one compound selected from the group consisting of a compound represented by the following formula (I-1) and a compound represented by the following formula (I-2), and satisfying either condition (a) or condition (b) below. Condition (a): The non-aqueous electrolyte further comprises a second component, wherein the second component comprises at least two compounds selected from the group consisting of the compound represented by formula (II), the compound represented by formula (III), the compound represented by formula (IV), and the compound represented by formula (V). Condition (b): The non-aqueous electrolyte further comprises a second component and a third component, wherein the second component comprises at least one compound selected from the group consisting of the compound represented by formula (II), the compound represented by formula (III), the compound represented by formula (IV), and the compound represented by formula (V), and the third component comprises at least one compound selected from the group consisting of the compound represented by formula (VI), the compound represented by formula (VII), the compound represented by formula (VIII-1), the compound represented by formula (VIII-2), the compound represented by formula (IX), the compound represented by formula (X), the compound represented by formula (XI), and the compound represented by formula (XII). (In formula (I-1), R １１ and R １２ These can be independently substituted with a halogen group, an oxa group (-O-), a carbonyl group (>C=O), and a sulfonyl group (>S(=O)). ２ This represents a divalent hydrocarbon group having 1 to 6 carbon atoms, which may contain at least one functional group selected from the group consisting of ). In formula (I-2), R １１ The substituents are a halogen group, an oxa group (-O-), a carbonyl group (>C=O), and a sulfonyl group (>S(=O)). ２ Represents a divalent hydrocarbon group having 1 to 6 carbon atoms, which may contain at least one functional group selected from the group consisting of ). １３ These can be independently substituted with a halogen group, a cyano group (-CN), an oxa group (-O-), a carbonyl group (>C=O), and a sulfonyl group (>S(=O)). ２ represents a hydrocarbon group having 1 to 12 carbon atoms which may contain at least one functional group selected from the group consisting of ).) (In formula (II), R ２１ represents a fluorocarbon group having 1 to 12 carbon atoms which may contain an oxa group (-O-) as a substituent, or a hydrocarbon group having 1 to 12 carbon atoms which contains a fluoro group (-F) as a substituent. M ＋ represents an alkali metal ion, an ammonium ion, an imidazolium ion, a pyridinium ion, a pyrrolidinium ion, a piperidinium ion, or a phosphonium ion. In formula (III), R ３１ represents a methylene group (-CH ２ -), an ethylene group (-CH ２ CH ２ -), or an n-propylene group (-CH ２ CH ２ CH ２ -). In formula (IV), R ４１ represents a methylene group (-CH ２ -), an ethylene group (-CH ２ CH ２ -), or an n-propylene group (-CH ２ CH ２ CH ２ -). R ４２ each independently represents a hydrocarbon group having 1 to 12 carbon atoms which may contain at least one functional group selected from the group consisting of a halogeno group and an oxa group (-O-) as a substituent. When R ４１ is a methylene group (-CH ２ -), h represents 1 or 2. When R ４１ is an ethylene group (-CH ２ CH ２ -), h represents an integer of 1 to 4. When R ４１ is an n-propylene group (-CH ２ CH ２ CH ２ -), h represents an integer of 1 to 6. In formula (V), R ５１ represents a methylene group (-CH ２ -), an ethylene group (-CH ２ CH ２ -), or an n-propylene group (-CH ２ CH ２ CH ２ Represents (-). ５２ Each of these independently represents the group represented by formula (v-1), the group represented by formula (v-2), the group represented by formula (v-3), the group represented by formula (v-4), the group represented by formula (v-5), the group represented by formula (v-6), or the group represented by formula (v-7). ５１ is a methylene group (-CH ２ When i is -, it represents either 1 or 2. ５１ is an ethylene group (-CH ２ CH ２ When i is -, it represents an integer from 1 to 4. ５１ is an n-propylene group (-CH ２ CH ２ CH ２ When i is -, i represents an integer from 1 to 6. In equation (v-3), R ５３ This represents a hydrocarbon group having 1 to 12 carbon atoms, which may contain at least one functional group selected from the group consisting of a halogen group and an oxa group (-O-) as a substituent. (In equation (VI), the double line, which is both solid and dotted, represents a single bond (-) or a double bond (=). ６１ represents a halogeno group, a fluorine carbide group having 1 to 12 carbon atoms which may contain an oxa group (-O-) as a substituent, or a hydrocarbon group having 1 to 12 carbon atoms which may contain at least one functional group selected from the group consisting of a fluoro group (-F) and an oxa group (-O-) as a substituent. j represents an integer from 0 to 4. In formula (VII), Q represents a boron atom (B) or a phosphorus atom (P). R ７１ Each independently represents a divalent hydrocarbon group having 1 to 6 carbon atoms, which may contain a single bond (-) or at least one functional group selected from the group consisting of a halogen group and an oxa group (-O-) as a substituent. Each independently represents a halogen group. When Q is a boron atom (B), a represents 1 or 2, when a is 1, b represents 2, and when a is 2, b represents 0. When Q is a phosphorus atom (P), a represents an integer from 1 to 3, when a is 1, b represents 4, when a is 2, b represents 2, and when a is 3, b represents 0. c represents an integer from 1 to 3. M ＋ M represents an alkali metal ion, ammonium ion, imidazolium ion, pyridinium ion, pyrrolidinium ion, piperidinium ion, or phosphonium ion. In formula (VIII-1), M ＋ represents an alkali metal ion, ammonium ion, imidazolium ion, pyridinium ion, pyrrolidinium ion, piperidinium ion, or phosphonium ion. In formula (VIII-2), two M ＋ Each of these independently represents an alkali metal ion, an ammonium ion, an imidazolium ion, a pyridinium ion, a pyrrolidinium ion, a piperidinium ion, or a phosphonium ion. In formula (IX), M ＋ R represents an alkali metal ion, ammonium ion, imidazolium ion, pyridinium ion, pyrrolidinium ion, piperidinium ion, or phosphonium ion. In formula (X), two R １０１ Each of these independently represents a fluorine carbide group having 1 to 12 carbon atoms, which may contain a fluoro group (-F), an oxa group (-O-) as a substituent, or a hydrocarbon group having 1 to 12 carbon atoms, which contains a fluoro group (-F) as a substituent. ＋ R represents an alkali metal ion, ammonium ion, imidazolium ion, pyridinium ion, pyrrolidinium ion, piperidinium ion, or phosphonium ion. In formula (XI), R １１１ Each independently represents a halogeno group, a 1-12 carbon atom fluorine carbide group which may contain an oxa group (-O-) as a substituent, or a 1-12 carbon atom hydrocarbon group which may contain at least one functional group selected from the group consisting of a fluoro group (-F) and an oxa group (-O-) as a substituent. m represents an integer from 0 to 2. In formula (XII), the two R １２１ Each of these independently represents a hydrocarbon group having 1 to 12 carbon atoms or a trialkylsilyl group having 3 to 18 carbon atoms.

2. The non-aqueous electrolyte according to claim 1, wherein the total content of the first component is 0.001% by mass to 5.0% by mass with respect to the total amount of the non-aqueous electrolyte.

3. The non-aqueous electrolyte according to claim 1, wherein the above condition (a) is met, and the total content of the second component is 0.001% by mass to 5.0% by mass with respect to the total amount of the non-aqueous electrolyte.

4. The non-aqueous electrolyte according to claim 1, which satisfies condition (b) above, and the total content of the second component is 0.001% by mass to 5.0% by mass with respect to the total amount of the non-aqueous electrolyte.

5. The non-aqueous electrolyte according to claim 1, wherein the above condition (b) is met, and the total content of the third component is 0.001% by mass to 20.0% by mass with respect to the total amount of the non-aqueous electrolyte.

6. The non-aqueous electrolyte according to claim 1, wherein the compound represented by formula (V) is at least one selected from the group consisting of the compound represented by the following formula (V-1), the compound represented by the following formula (V-2), the compound represented by the following formula (V-3), the compound represented by the following formula (V-4), the compound represented by the following formula (V-5), the compound represented by the following formula (V-6), and the compound represented by the following formula (V-7).

7. A non-aqueous electrolyte comprising one or more compounds selected from the group consisting of compounds represented by the following formula (I-1) and compounds represented by the following formula (I-2), and one or more compounds selected from the group consisting of compounds represented by the following formula (IV). (In formula (I-1), R １１ and R １２ The substituents are a halogen group, an oxa group (-O-), a carbonyl group (>C=O), and a sulfonyl group (>S(=O)). ２ This represents a divalent hydrocarbon group having 1 to 6 carbon atoms, which may contain at least one functional group selected from the group consisting of ). In formula (I-2), R １１ The substituents are a halogen group, an oxa group (-O-), a carbonyl group (>C=O), and a sulfonyl group (>S(=O)). ２ Represents a divalent hydrocarbon group having 1 to 6 carbon atoms, which may contain at least one functional group selected from the group consisting of ). １３ These can be independently substituted with a halogen group, a cyano group (-CN), an oxa group (-O-), a carbonyl group (>C=O), and a sulfonyl group (>S(=O)). ２ This represents a hydrocarbon group having 1 to 12 carbon atoms, which may contain at least one functional group selected from the group consisting of the following: (In formula (IV), R ４１ is a methylene group (-CH ２ -), ethylene group (-CH ２ CH ２ -), or n-propylene group (-CH ２ CH ２ CH ２ Represents (-). ４２ Each of these independently represents a hydrocarbon group having 1 to 12 carbon atoms, which may contain at least one functional group selected from the group consisting of a halogen group and an oxa group (-O-) as a substituent. ４１ is a methylene group (-CH ２ When h is -, it represents 1 or 2. ４１ is an ethylene group (-CH ２ CH ２ When h is -, h represents an integer from 1 to 4. ４１ is an n-propylene group (-CH ２ CH ２ CH ２ When h is -, it represents an integer from 1 to 6.

8. A non-aqueous electrolyte secondary battery comprising a positive electrode, a negative electrode, a non-aqueous electrolyte according to any one of claims 1 to 7, and a separator.

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