Nonaqueous electrolytic solution secondary battery

Abstract

In the present invention, a negative electrode including, as a negative electrode active material, Si-C particles that include a silicon component-containing Si domain and a carbon component-containing C domain, is combined with a nonaqueous electrolytic solution containing, inter alia, a compound represented by formula (I), whereby increased resistance after charge-discharge cycles can be suppressed.

Description

Nonaqueous electrolyte secondary battery

[0001] This invention relates to a non-aqueous electrolyte secondary battery.

[0002] Lithium-ion batteries and other energy storage devices, which are small, lightweight, and high-output, have become even more high-performance in recent years. With this improvement in performance, their use is expanding not only in small electrical products but also in large products such as automobiles. Lithium-ion batteries are required to meet specific requirements regarding various characteristics such as output characteristics and charge / discharge characteristics. For example, it is known that when a negative electrode active material containing silicon is used, the charge / discharge capacity is larger compared to when a negative electrode active material containing only carbon is used, but the resistance after the charge / discharge cycle tends to increase significantly.

[0003] Patent Document 1 reports that by using a non-aqueous electrolyte containing less than a specific amount of a particular fluorinated ether, it is possible to improve the lifespan and suppress the increase in resistance in a battery having a negative electrode material containing silicon and carbon elements.

[0004] Japanese Patent Publication No. 2025-913

[0005] One aspect of this disclosure aims to provide a non-aqueous electrolyte secondary battery that uses a silicon-containing negative electrode active material and can suppress the increase in resistance after a charge-discharge cycle.

[0006] As a result of diligent research to solve the above problems, the present inventors have found that by combining a negative electrode containing Si-C particles, which include Si domains containing silicon components and C domains containing carbon components, as a negative electrode active material, with a non-aqueous electrolyte containing a specific compound, a non-aqueous electrolyte secondary battery can be obtained that suppresses the increase in resistance after charge-discharge cycles, and have completed this disclosure. Specifically, one aspect of this disclosure is as follows.

[0007] <1> A non-aqueous electrolyte secondary battery comprising a positive electrode, a negative electrode, a non-aqueous electrolyte, and a separator, wherein the negative electrode comprises a current collector and a negative electrode composite layer formed on the current collector and containing a negative electrode active material, the negative electrode active material comprises Si-C particles containing Si domains containing silicon components and C domains containing carbon components, and the non-aqueous electrolyte contains one or more compounds selected from the group consisting of a compound represented by the following formula (I), a compound represented by the following formula (II), a compound represented by the following formula (III-1), a compound represented by the following formula (III-2), a compound represented by the following formula (IV), a compound represented by the following formula (V), a compound represented by the following formula (VI), a compound represented by the following formula (VII), a compound represented by the following formula (VIII), a compound represented by the following formula (IX), a compound represented by the following formula (X-1), a compound represented by the following formula (X-2), a compound represented by the following formula (XI), a compound represented by the following formula (XII), and a compound represented by the following formula (XIII).

[0008]

[0009] In formula (I), R １１ 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 may contain at least one functional group selected from the group consisting of a fluoro group and an oxa group (-O-) as a substituent, and h represents an integer from 0 to 2. In formula (II), R ２１ Each 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 may contain at least one functional group selected from the group consisting of a fluoro group and an oxa group (-O-) as a substituent, where i represents an integer from 0 to 3. In formulas (III-1) and (III-2), 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 (IV), Q represents a boron atom (B) or a phosphorus atom (P), and R４１ each independently represents a single bond (-) or 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 halogeno group and an oxa group (-O-) as a substituent, X each independently represents a halogeno group, M ＋ each 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, when Q is a boron atom (B), a represents 1 or 2, b represents 2 when a is 1 and 0 when a is 2, when Q is a phosphorus atom (P), a represents an integer of 1 to 3, b represents 4 when a is 1, 2 when a is 2, and 0 when a is 3, and c represents an integer of 1 to 3. In formula (V), R ５１ each independently represents a fluoro group (-F), 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 alkaline earth metal ion, an ammonium ion, an imidazolium ion, a pyridinium ion, a pyrrolidinium ion, a piperidinium ion, or a phosphonium ion. In formula (VI), R ６１ represents a fluoro group (-F), 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, R ６２ 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 fluoro group (-F) and an oxa group (-O-) as a substituent, or a fluorocarbon group having 1 to 12 carbon atoms which may contain an oxa group (-O-) as a substituent, M ＋ represents an alkali metal ion, an alkaline earth metal ion, an ammonium ion, an imidazolium ion, a pyridinium ion, a pyrrolidinium ion, a piperidinium ion, or a phosphonium ion. In formula (VII), R ７１Each 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, M ＋ R represents an alkali metal ion, alkaline earth metal ion, ammonium ion, imidazolium ion, pyridinium ion, pyrrolidinium ion, piperidinium ion, or phosphonium ion. In formula (VIII), R ８１ Each independently 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 may contain a fluoro group (-F) as a substituent, and j represents an integer from 1 to 4. In formula (IX), a double line consisting of a solid line and a dotted line represents a single bond (-) or a double bond (=), and R ９１ Each 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 may contain at least one functional group selected from the group consisting of a fluoro group and an oxa group (-O-) as a substituent, where k is an integer from 0 to 4. In formulas (X-1) and (X-2), R １０１ and R １０２ 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 R 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 ) １０３ 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 ). In formula (XI), R １１１ R represents an m+1 valent hydrocarbon group having 1 to 24 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, where m is an integer from 0 to 4. In formula (XII), R１２１ R represents an n+1 valent hydrocarbon group having 1 to 24 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, where n is an integer from 0 to 4. In formula (XIII), R １３１ is a methylene group (-CH ２ -), ethylene group (-CH ２ CH ２ -), or n-propylene group (-CH ２ CH ２ CH ２ -) represents R １３２ Each independently represents a hydrocarbon group having 1 to 6 carbon atoms, a group represented by formula (xiiii-3), a group represented by formula (xiiii-4), a group represented by formula (xiiii-5), a group represented by formula (xiiii-6), a group represented by formula (xiiii-7), or a group represented by formula (xiiii-8), which may each contain at least one functional group selected from the group consisting of a halogen group (-X) and an oxa group (-O-) as a substituent, and p is R １３１ is a methylene group (-CH ２ When -, an integer from 0 to 2, R １３１ is an ethylene group (-CH ２ CH ２ When -, an integer from 0 to 4, R １３１ is an n-propylene group (-CH ２ CH ２ CH ２When -, it represents an integer from 0 to 6. <2> The non-aqueous electrolyte secondary battery according to <1>, wherein the non-aqueous electrolyte comprises: a first component which is one or more selected from the group consisting of the compound represented by formula (I) and the compound represented by formula (II); and a second component which is one or more selected from the group consisting of the compound represented by formula (III-1), the compound represented by formula (III-2), the compound represented by formula (IV), the compound represented by formula (V), the compound represented by formula (VI), the compound represented by formula (VII), the compound represented by formula (VIII), the compound represented by formula (IX), the compound represented by formula (X-1), the compound represented by formula (X-2), the compound represented by formula (XI), the compound represented by formula (XII), and the compound represented by formula (XIII). <3> The non-aqueous electrolyte secondary battery according to <2>, wherein the total content of the first component is 0.0001% by mass to 10% by mass with respect to the total amount of the non-aqueous electrolyte. <4> The non-aqueous electrolyte secondary battery according to <2> or <3>, wherein the total content of the second component is 0.0001% by mass to 20% by mass relative to the total amount of the non-aqueous electrolyte. <5> The Si-C particles are at 1450 cm⁻¹ in the Raman spectrum. －１ ~1700cm －１ Maximum peak intensity I Ｇ 450 cm －１ ~600cm －１ Maximum peak intensity I Ｓｉ Ratio I Ｓｉ / I Ｇ However, the particles are 15 or less, a non-aqueous electrolyte secondary battery as described in any of <1> to <4>. <6> The Si-C particles are, in the Raman spectrum, 1450 cm⁻¹ －１ ~1700cm －１ Maximum peak intensity I Ｇ 1200 cm －１ ~1450cm －１ Maximum peak intensity I Ｄ Ratio I Ｄ / I Ｇ However, the particles are 10 or less, a non-aqueous electrolyte secondary battery as described in any of <1> to <5>. <7> The Si-C particles have an oxygen content m measured by X-ray fluorescence analysis (XRF). Ｏ，ＸＲＦContent m of silicon component relative to [mass %] Ｓｉ，ＸＲＦ ratio m of [mass %] Ｓｉ，ＸＲＦ / m Ｏ，ＸＲＦ is a particle having a value of 10 or more, the non-aqueous electrolyte secondary battery according to any one of <1> to <6>. <8> The Si-C particles are particles in which the ratio mSi(SiO2),ICP / mSi(total),ICP of the content of the silicon component derived from silicon dioxide (SiO ２ ) mSi(SiO2),ICP [mass %] to the content of the silicon component mSi(total),ICP [mass %] measured by inductively coupled plasma atomic emission spectrometry (ICP-AES) is 0.80 or less, the non-aqueous electrolyte secondary battery according to any one of <1> to <7>. <9> The non-aqueous electrolyte secondary battery according to any one of <1> to <8>, wherein the total content of the Si-C particles is 1 mass % to 30 mass % relative to the total amount of the negative electrode active material.

[0010] According to one aspect of the present disclosure, in a non-aqueous electrolyte secondary battery using a negative electrode active material containing a silicon component, an increase in resistance after charge-discharge cycles can be suppressed.

[0011] Figure 1 is a schematic cross-sectional view showing a laminated non-aqueous electrolyte secondary battery precursor which is an example of the precursor of the non-aqueous electrolyte secondary battery according to one aspect of the present disclosure. Figure 2 is a schematic cross-sectional view showing a coin-type non-aqueous electrolyte secondary battery precursor which is another example of the precursor of the non-aqueous electrolyte secondary battery according to one aspect of the present disclosure. Figure 3 is a Raman spectrum obtained by microscopic Raman spectrometry measurement of Si-C particles 1 to Si-C particles 3 in Examples. Figure 4 is an EELS spectrum obtained by TEM-EELS measurement of Si-C particles 1 in Examples.

[0012] In describing the present disclosure, specific examples will be given for explanation, but 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.

[0013] In the present disclosure, a numerical range represented by "to" means a range including the numerical values before and after "to" as the lower limit value and the upper limit value. Regarding the numerical ranges described stepwise in the present disclosure, an upper limit value or a lower limit value described in one numerical range may be replaced with an upper limit value or a lower limit value of another stepwise described numerical range. Further, in the numerical ranges described in the present disclosure, the upper limit value or the lower limit value of the numerical range may be replaced with a value shown in the Examples. In the present disclosure, the amount of each component in a composition means the total amount of the plurality of substances present in the composition when a plurality of substances corresponding to each component are 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 "process" is not limited to an independent process, and is included in the term as long as the intended purpose of the process is achieved even if the process cannot be clearly distinguished from other processes.

[0014] [Nonaqueous Electrolyte Secondary Battery] A nonaqueous electrolyte secondary battery which is one aspect of the present disclosure (hereinafter may be abbreviated as "the present battery") includes a positive electrode, a negative electrode, a nonaqueous electrolyte, and a separator. The negative electrode includes a current collector and a negative electrode mixture layer formed on the current collector and containing a negative electrode active material. The negative electrode active material includes Si-C particles (hereinafter may be abbreviated as "the present Si-C particles") including an Si domain containing a silicon component (hereinafter may be abbreviated as "the Si domain") and a C domain containing a carbon component (hereinafter may be abbreviated as "the C domain"). The nonaqueous electrolyte (hereinafter may be abbreviated as "the present nonaqueous electrolyte") contains one or more selected from the group consisting of a compound represented by the following formula (I), a compound represented by the following formula (II), a compound represented by the following formula (III-1), a compound represented by the following formula (III-2), a compound represented by the following formula (IV), a compound represented by the following formula (V), a compound represented by the following formula (VI), a compound represented by the following formula (VII), a compound represented by the following formula (VIII), a compound represented by the following formula (IX), a compound represented by the following formula (X-1), a compound represented by the following formula (X-2), a compound represented by the following formula (XI), a compound represented by the following formula (XII), and a compound represented by the following formula (XIII).

[0015]

[0016] The present inventors have diligently studied how to suppress the increase in resistance after charge-discharge cycles of a non-aqueous electrolyte secondary battery using a negative electrode active material containing silicon components. As a result, they have found that by combining a negative electrode containing Si-C particles, which contain Si domains containing silicon components and C domains containing carbon components, with a non-aqueous electrolyte containing a compound represented by formula (I), the increase in resistance after charge-discharge cycles can be suppressed. In this disclosure, "suppressing the increase in resistance after charge-discharge cycles" means being excellent at suppressing the increase in at least one of the increase rates of charging resistance and discharge resistance after charge-discharge cycles.

[0017] In this disclosure, "Si domain" refers to a three-dimensional region in the Si-C particle that contains silicon as a component. Similarly, in this disclosure, "C domain" refers to a three-dimensional region in the Si-C particle that contains carbon as a component. Furthermore, the Si domain and the C domain may be domains embedded within other domains. Also, in this disclosure, "Si-C particle" refers to a particle containing both Si domains and C domains as described above, and does not mean a silicon carbide particle.

[0018] The following provides a detailed explanation of the "negative electrode," "non-aqueous electrolyte," "positive electrode," "separator," and "current collector," etc.

[0019] <Negative Electrode> The negative electrode can usually be manufactured by dispersing a negative electrode active material, a binder, and optionally a conductive additive and / or a thickener in a solvent to form a slurry, applying this slurry to a current collector, drying it, and compressing it to form a negative electrode composite layer (also called the "negative electrode active material layer") on the current collector. In this battery as well, the negative electrode includes a current collector and a negative electrode composite layer formed on the current collector and containing the negative electrode active material. The "negative electrode active material," "binder," "conductive additive," and "thickener" will be described in detail below.

[0020] (Negative electrode active material) In this battery, the negative electrode active material contains Si-C particles, which contain a Si domain containing a silicon component and a C domain containing a carbon component. The silicon content of these Si-C particles is measured by X-ray fluorescence analysis (XRF). Ｓｉ，ＸＲＦ The [mass%] is usually 10% to 90% by mass, preferably 20% or more by mass, more preferably 30% or more by mass, even more preferably 40% or more by mass, and also preferably 80% or less by mass, more preferably 70% or less by mass, and even more preferably 60% or less by mass. When the silicon content is within the above range, it becomes easier to increase the charge / discharge capacity and improve the lifespan performance.

[0021] The carbon content of these Si-C particles, as measured by X-ray fluorescence analysis (XRF), is m Ｃ，ＸＲＦ The [mass%] is usually 10 to 90 mass%, preferably 15 mass% or more, more preferably 20 mass% or more, even more preferably 30 mass% or more, preferably 80 mass% or less, more preferably 70 mass% or less, even more preferably 60 mass% or less, and particularly preferably 50 mass% or less. When the carbon content is within the above range, it becomes easier to increase the charge / discharge capacity and improve the lifespan performance.

[0022] The oxygen content of these Si-C particles, as measured by X-ray fluorescence analysis (XRF), is m Ｏ，ＸＲＦ The [mass%] is usually 0 to 30 mass%, preferably 20 mass% or less, more preferably 15 mass% or less, even more preferably 10 mass% or less, and particularly preferably 5 mass% or less. When the oxygen content is within the above range, it becomes easier to increase the charge / discharge capacity and improve the lifespan performance.

[0023] The oxygen content of these Si-C particles, as measured by X-ray fluorescence analysis (XRF), is m Ｏ，ＸＲＦ Silicon content m per [mass%] Ｓｉ，ＸＲＦ [Mass %] ratio m Ｓｉ，ＸＲＦ / m Ｏ，ＸＲＦ m is usually 3 or more, preferably 4 or more, more preferably 10 or more, and even more preferably 15 or more. Ｓｉ / m ＯIf the above range is maintained, it becomes easier to increase the charge / discharge capacity and improve the lifespan performance.

[0024] The silicon content (also referred to as "total Si content") mSi(total),ICP[mass%] of these Si-C particles, as measured by inductively coupled plasma atomic emission spectroscopy (ICP-AES), is typically 10% to 90% by mass, preferably 20% or more by mass, more preferably 30% or more by mass, even more preferably 40% or more by mass, and also preferably 80% or less by mass, more preferably 70% or less by mass, and even more preferably 60% or less by mass. When the silicon content is within the above range, it becomes easier to increase the charge / discharge capacity and improve the lifespan performance.

[0025] The silicon dioxide (SiO₂) of these Si-C particles is measured by inductively coupled plasma emission spectroscopy (ICP-AES). ２ The amount of silicon component derived from ("SiO ２ Also referred to as "derived Si content." The mSi(SiO2),ICP [mass%] is usually 0 mass% to 50 mass%, preferably 40 mass% or less, more preferably 30 mass% or less, and even more preferably 20 mass% or less. When the silicon content is within the above range, it becomes easier to increase the charge / discharge capacity and improve the lifespan performance.

[0026] The content of silicon components derived from metallic silicon (also referred to as "metallic Si content") mSi(Si),ICP [mass%], measured by inductively coupled plasma atomic emission spectroscopy (ICP-AES) of these Si-C particles, is usually 10% to 100% by mass, preferably 20% or more by mass, more preferably 30% or more by mass, and even more preferably 40% or more by mass. When the silicon component content is within the above range, it becomes easier to increase the charge / discharge capacity and improve the lifespan performance. When the silicon components contained in the Si-C particles consist of silicon components derived from silicon dioxide and silicon components derived from metallic silicon, the content of the metallic silicon component mSi(Si),ICP [mass%] is the total Si content mSi(total),ICP [mass%] and SiO ２The difference in the amount of Si derived, i.e., the total amount of Si mSi (total), ICP [mass%], is used to determine SiO ２ The value may also be calculated by subtracting the amount of Si derived from the material.

[0027] The silicon content of these Si-C particles, measured by inductively coupled plasma atomic emission spectroscopy (ICP-AES), is as follows: mSi (total), ICP [mass%], and silicon dioxide (SiO₂) ２ The ratio of the silicon content mSi(SiO2),ICP [mass%] derived from ) to the silicon dioxide (SiO2),ICP / mSi(total),ICP is usually 0.80 or less, preferably 0.50 or less, more preferably 0.40 or less, and even more preferably 0.30 or less. When mSi(SiO2),ICP / mSi(total),ICP is within the above range, it becomes easier to increase the charge / discharge capacity and improve the lifespan performance. Furthermore, the above ratio is the ratio of silicon dioxide (SiO2),ICP [mass%] to the silicon content mSi(total),ICP [mass%] measured by inductively coupled plasma atomic emission spectroscopy (ICP-AES) of the Si-C particles. ２ The ratio may be expressed as an amount [mass%]. Silicon dioxide (SiO ２ The amount [mass%] is SiO ２ The amount of Si derived from mSi(SiO2), ICP [mass%] is calculated using the atomic weight of Si (28.09) and SiO2. ２ The molecular weight of 60.08 can be calculated based on the following formula: SiO ２ Amount=SiO ２ Derived Si content mSi(SiO2), ICP [mass%] × 60.08 / 28.09

[0028] The above mSi(total),ICP, mSi(SiO2),ICP, and mSi(total),IC can be measured by inductively coupled plasma atomic emission spectroscopy (ICP-AES) using the method shown in the examples described later.

[0029] The silicon element content [mass%] in the Si domain of these Si-C particles is typically 65% ​​by mass or more, preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, and particularly preferably 95% by mass or more. When the silicon component content is within the above range, it becomes easier to increase the charge / discharge capacity and improve the lifespan performance.

[0030] The oxygen content [mass%] in the Si domain of these Si-C particles is typically 35% by mass or less, preferably 30% by mass or less, more preferably 20% by mass or less, even more preferably 10% by mass or less, and particularly preferably 5% by mass or less. When the oxygen content is within the above range, it becomes easier to increase the charge / discharge capacity and improve the lifespan performance.

[0031] The carbon content [mass%] in the C domain of these Si-C particles is typically 60% by mass or more, preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, and particularly preferably 95% by mass or more. When the carbon content is within the above range, it becomes easier to increase the charge / discharge capacity and improve the lifespan performance.

[0032] The oxygen content [mass%] in the C domain of these Si-C particles is typically 30% by mass or less, preferably 30% by mass or less, more preferably 20% by mass or less, even more preferably 10% by mass or less, and particularly preferably 5% by mass or less. When the oxygen content is within the above range, it becomes easier to increase the charge / discharge capacity and improve the lifespan performance.

[0033] The median diameter (D50) of these Si-C particles is typically 1 μm to 30 μm, preferably 3 μm or more, more preferably 5 μm or more, and also preferably 20 μm or less, more preferably 15 μm or less. The above median diameter can be measured using a laser diffraction / scattering particle size distribution analyzer.

[0034] The tap density of the present Si-C particles is usually from 0.1 g / mL to 10 g / mL, preferably 0.4 g / mL or more, more preferably 0.6 g / mL or more, and preferably 6.0 g / mL or less, more preferably 4.0 g / mL or less. The above tap density can be measured by using a powder density meter, performing tapping 1000 times with a stroke length of 10 mm, and calculating the tap density from the volume at that time and the mass of the sample.

[0035] The BET specific surface area of the present Si-C particles is usually 1.0 m ２ / g to 5.0 m ２ / g, preferably 1.2 m ２ / g or more, more preferably 1.5 m ２ / g or more, and preferably 4.5 m ２ / g or less, more preferably 4.0 m ２ / g or less, still more preferably 3.0 m ２ / g or less. The above BET specific surface area can be measured using a surface area meter.

[0036] The present Si-C particles preferably have a ratio of the maximum peak intensity I at 450 to 600 cm in the Raman spectrum －１ to 1700 cm －１ to the maximum peak intensity I at Ｇ 1450 cm －１ of I Ｓｉ / I Ｓｉ of 15 or less. I Ｇ is more preferably 2 or less, still more preferably 1 or less, particularly preferably 0.5 or less, most preferably 0.1 or less, and usually 0.001 or more. When I Ｓｉ / I Ｇ is within the above range, the increase in resistance after charge-discharge cycles can be easily suppressed. Ｓｉ / I Ｇ

[0037] The present Si-C particles have, relative to the maximum peak intensity I at 1450 cm in the Raman spectrum －１ to 1700 cm －１ , the maximum peak intensity I at 1200 cm Ｇ to 1450 cm －１ －１ Ｄ ​​​Ratio I Ｄ / I Ｇ However, it is preferable that it be 10 or less. Ｄ / I Ｇ It is more preferably 5 or less, even more preferably 3 or less, particularly preferably 2 or less, most preferably 1 or less, and usually 0.1 or more. Ｄ / I Ｇ If the value is within the above range, it becomes easier to suppress the increase in resistance after the charge-discharge cycle.

[0038] Examples of Si-C particle shapes include fibrous, spherical, potato-shaped, and flake-shaped.

[0039] Specific forms of these Si-C particles include the following: • Porous carbon-derived particles in which porous carbon forms C domains and Si domains are formed on at least one surface inside and outside the pores of the porous carbon (hereinafter sometimes abbreviated as "porous carbon-derived particles"). • Silicon-carbon composite particles in which particles containing silicon components form Si domains and C domains are formed between silicon-containing particles (hereinafter sometimes abbreviated as "silicon-carbon composite particles"). Furthermore, porous carbon-derived core-shell particles (hereinafter sometimes abbreviated as "porous carbon-derived core-shell particles") are also included, where porous carbon-derived particles form the core and the surface of the core is covered with a layer containing carbon components to form the shell. Additionally, silicon-carbon composite core-shell particles (hereinafter sometimes abbreviated as "silicon-carbon composite core-shell particles") are also included, where silicon-carbon composite particles form the core and the surface of the core is covered with a layer containing carbon components to form the shell. Components included in the Si domains include (metallic) silicon and silicon oxide.

[0040] In this battery, the negative electrode active material contains the Si-C particles, but it is preferable that it also contains elemental carbon particles. Examples of elemental carbon particles include graphite (natural graphite, artificial graphite) particles, carbon black particles, activated carbon particles, amorphous carbon particles, etc. Examples of artificial graphite include graphitized MCMB and graphitized MCF. Examples of amorphous carbon materials include hard carbon, coke, mesocarbon microbeads (MCMB) fired at 1500°C or below, and mesophase pitch carbon fiber (MCF).

[0041] The total content of these Si-C particles in the negative electrode active material of this battery is usually 1% to 30% by mass, preferably 3% or more by mass, more preferably 5% or more by mass, and preferably 25% or less by mass, and more preferably 15% or less by mass, relative to the total amount of the negative electrode active material (when the total amount of the negative electrode active material is considered as 100% by mass). When the total content of these Si-C particles is within the above range, it becomes easier to increase the charge and discharge capacity.

[0042] The total content of elemental carbon particles in the negative electrode active material of this battery is typically 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, relative to the total amount of negative electrode active material (when the total amount of negative electrode active material is considered as 100% by mass). When the total content of these particles is within the above range, it becomes easier to increase the charge and discharge capacity.

[0043] The total content of the negative electrode active material in the negative electrode composite layer is typically 70% to 99.5% by mass, preferably 75% or more, and preferably 99% or less by mass, relative to the total amount of the negative electrode composite layer (when the entire negative electrode composite layer is considered as 100% by mass).

[0044] (Binder) The negative electrode active material in the present battery may contain a binder. Examples of the binder for the negative electrode include styrene-butadiene rubber (SBR) and the like. The total content of the copolymer of the binder in the negative electrode mixture layer is usually 0.1 mass% to 5 mass% with respect to the total amount of the negative electrode mixture layer (when the entire negative electrode mixture layer is taken as 100 mass%), preferably 0.5 mass% or more, more preferably 1.0 mass% or more, preferably 3 mass% or less, and more preferably 2 mass% or less.

[0045] (Conductive Aid) It is preferable that the negative electrode mixture layer further contains a conductive aid. Examples of the conductive aid for the negative electrode include carbon black (for example, acetylene black), carbon nanotubes, amorphous whiskers, graphite and the like.

[0046] The total content of the conductive aid in the negative electrode mixture layer is usually 0.01 mass% to 3 mass% with respect to the total amount of the negative electrode mixture layer (when the entire negative electrode mixture layer is taken as 100 mass%), preferably 0.05 mass% or more, more preferably 0.1 mass% or more, preferably 2 mass% or less, and more preferably 1 mass% or less.

[0047] (Thickener) It is preferable that the negative electrode mixture layer further contains a thickener. By containing the thickener, the viscosity of the slurry can be easily adjusted, and productivity is improved. Examples of the thickener for the negative electrode include cellulose derivatives such as carboxymethyl cellulose (CMC), carboxyethyl cellulose, and hydroxyethyl cellulose, polyoxyethylene and modified products thereof, polyvinyl alcohol and modified products thereof, polysaccharides and the like.

[0048] The total content of the thickener in the negative electrode mixture layer is usually 0.1 mass% to 5 mass% with respect to the total amount of the negative electrode mixture layer (when the entire negative electrode mixture layer is taken as 100 mass%), preferably 0.5 mass% or more, more preferably 1.0 mass% or more, preferably 3 mass% or less, and more preferably 2 mass% or less.

[0049] The 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 also be a mixed solvent obtained by mixing the aforementioned solvents.

[0050] (Current collector) Examples of materials for the negative electrode current collector include copper, nickel, stainless steel, and nickel-plated steel.

[0051] <Non-aqueous electrolyte> A non-aqueous electrolyte usually contains a non-aqueous solvent, an electrolyte, and an additive. However, this non-aqueous electrolyte contains one or more compounds selected from the group consisting of the following compounds: the compound represented by formula (I), the compound represented by formula (II), the compound represented by formula (III-1), the compound represented by formula (III-2), the compound represented by formula (IV), the compound represented by formula (V), the compound represented by formula (VI), the compound represented by formula (VII), the compound represented by formula (VIII), the compound represented by formula (IX), the compound represented by formula (X-1), the compound represented by formula (X-2), the compound represented by formula (XI), the compound represented by formula (XII), and the compound represented by formula (XIII). Note that some compounds represented by formula (III-1), etc., act as non-aqueous solvents or electrolytes, but as long as they are included in the non-aqueous electrolyte, it is not considered relevant whether they act as a non-aqueous solvent, electrolyte, or additive.

[0052]

[0053] The following provides a detailed explanation of "compounds represented by formula (I)," "compounds represented by formula (II)," etc.

[0054] (Compound represented by formula (I)) This non-aqueous electrolyte may contain a compound represented by the following formula (I).

[0055]

[0056] In formula (I), R １１Each 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 may contain at least one functional group selected from the group consisting of a fluoro group and an oxa group (-O-) as a substituent, and h represents an integer from 0 to 2.

[0057] R １１ These terms independently represent "fluoro group (-F)", "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 may contain at least one functional group selected from the group consisting of a fluoro group and an oxa group (-O-) as a substituent". However, "fluorocarbon group" means a group in which all hydrogen atoms of the hydrocarbon group are replaced with fluorine atoms. "Fluorine carbon group" is also sometimes called a "fluorinated hydrocarbon group" or "fluorinated carbon group", and is a concept that includes perfluoroalkyl groups. Furthermore, a fluorocarbon group is not limited to a fluorocarbon group having a linear structure, but may also 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 (specifically, a carbon-carbon double bond structure and a carbon-carbon triple bond structure). Also, "a hydrocarbon group having 1 to 12 carbon atoms which contains a fluoro group (-F) as a substituent" means a group in which one or more hydrogen atoms of the hydrocarbon group are replaced with fluorine atoms. Furthermore, the phrase "may contain at least one functional group selected from the group consisting of fluoro groups and oxa groups (-O-) as substituents" means that the hydrogen atoms of hydrocarbon groups, etc., may be substituted with halogen groups such as fluoro groups (-F), chloro groups (-Cl), bromo groups (-Br), and iodo groups (-I), and that carbon atoms of hydrocarbon groups, etc., may also be substituted with oxa groups (-O-).

[0058] R １１ When R is a fluorine carbide group, the number of carbon atoms is preferably 10 or less, more preferably 8 or less, even more preferably 6 or less, and particularly preferably 4 or less. １１When the group is a hydrocarbon group, the number of carbon atoms is preferably 10 or less, more preferably 8 or less, even more preferably 6 or less, and particularly preferably 4 or less.

[0059] R １１ 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 CH２ 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 ), trifluoromethoxyphenyl group (-C ６ H ４ OCF ３ Examples include the fluoro group (-F) and the trifluoromethyl group (-CF). ３ ) is particularly preferable.

[0060] h represents an integer between 0 and 2, but it is particularly preferable that it be 0.

[0061] The compound represented by formula (I) may be one or more selected from the group consisting of vinylene carbonate (VC) represented by formula (I-1) below, carbonate represented by formula (I-2) below, and carbonate (TFPC) represented by formula (I-3) below. Note that this non-aqueous electrolyte may contain two or more compounds represented by formula (I).

[0062]

[0063] The content of the compound represented by formula (I) in this non-aqueous electrolyte is usually 0.01% by mass or more and 5.0% 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 as 100% by mass), preferably 0.1% by mass or more as the lower limit, more preferably 0.3% by mass or more, even more preferably 0.6% by mass or more, and particularly preferably 0.9% by mass or more as the lower limit, preferably 4.0% by mass or less, more preferably 3.0% by mass or less, even more preferably 2.0% by mass or less, and particularly preferably 1.0% by mass or less as the upper limit. When the content of these compounds is within the above range, it becomes easier to suppress the increase in resistance after the charge-discharge cycle.

[0064] (Compound represented by formula (II)) This non-aqueous electrolyte may contain a compound represented by the following formula (II).

[0065]

[0066] In formula (II), R ２１ 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 may contain at least one functional group selected from the group consisting of a fluoro group and an oxa group (-O-) as a substituent, where i represents an integer from 0 to 3.

[0067] R ２１ These terms independently represent "fluoro group (-F)", "a fluorine carbide group having 1 to 12 carbon atoms that may contain an oxa group (-O-) as a substituent", or "a hydrocarbon group having 1 to 12 carbon atoms that may contain at least one functional group selected from the group consisting of a fluoro group and an oxa group (-O-) as a substituent", but "fluorine carbide group", etc. are synonymous with the above.

[0068] R ２１ When R is a fluorine carbide group, the number of carbon atoms is preferably 10 or less, more preferably 8 or less, even more preferably 6 or less, and particularly preferably 4 or less. ２１ When the group is a hydrocarbon group, the number of carbon atoms is preferably 10 or less, more preferably 8 or less, even more preferably 6 or less, and particularly preferably 4 or less.

[0069] R ２１ 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 ), trifluoromethoxyphenyl group (-C ６ H ４ OCF ３ Examples include the following. Among these, the fluoro group (-F) is particularly preferred.

[0070] i represents an integer between 0 and 3, but it is particularly preferable that it be 0.

[0071] The compound represented by formula (II) may be one or more selected from the group consisting of monofluoroethylene carbonate (FEC) represented by formula (II-1) and difluoroethylene carbonate (DFEC) represented by formula (II-2) below. Note that this non-aqueous electrolyte may contain two or more compounds represented by formula (II).

[0072]

[0073] The content of the compound represented by formula (II) in this non-aqueous electrolyte is usually 0.01% by mass or more and 20% 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), preferably 0.1% by mass or more as the lower limit, more preferably 0.3% by mass or more, even more preferably 0.6% by mass or more, and particularly preferably 0.9% by mass or more, and preferably 18% by mass or less as the upper limit, more preferably 15% by mass or less, even more preferably 10% by mass or less, and particularly preferably 5.0% by mass or less. When the content of these compounds is within the above range, it becomes easier to suppress the increase in resistance after the charge-discharge cycle.

[0074] (Compound represented by formula (III-1) and compound represented by formula (III-2) below) This non-aqueous electrolyte may contain at least one compound selected from the group consisting of the compound represented by formula (III-1) below and the compound represented by formula (III-2) below.

[0075]

[0076] In equations (III-1) and (III-2), M ＋ Each of these independently represents an alkali metal ion, ammonium ion, imidazolium ion, pyridinium ion, pyrrolidinium ion, piperidinium ion, or phosphonium ion.

[0077] M ＋This represents "alkali metal ions," "ammonium ions," "imidazolium ions," "pyridinium ions," "pyrrolidinium ions," "piperidinium ions," or "phosphonium ions," but as an alkali metal ion, lithium ions (Li ＋ ), sodium ions (Na ＋ ), potassium ions (K ＋ Examples of ammonium ions include the ion represented by the following formula (m1), imidazolium ions include the ion represented by the following formula (m2), pyridinium ions include the ion represented by the following formula (m3), pyrrolidinium ions include the ion represented by the following formula (m4), piperidinium ions include the ion represented by the following formula (m5), and phosphonium ions include the ion represented by the following formula (m6).

[0078]

[0079] 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<). ＋ For example, lithium ion (Li ＋ It is especially preferable that it be of the following nature.

[0080] The compounds represented by formula (III-1) and formula (III-2) are as follows: Lithium difluorophosphate (LiPO) represented by formula (III-1-1) ２ F ２ ), and lithium monofluorophosphate (Li) represented by the following formula (III-2-1) ２ PO ３ One or more compounds selected from the group consisting of F) etc. are mentioned. Furthermore, this non-aqueous electrolyte may contain two or more compounds selected from the group consisting of compounds represented by formula (III-1) and compounds represented by formula (III-2).

[0081]

[0082] The content of one or more compounds selected from the group consisting of the compound represented by formula (III-1) and the compound represented by formula (III-2) in this non-aqueous electrolyte is usually 0.001% by mass or more and 10% 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), preferably 0.01% by mass or more as the lower limit, more preferably 0.1% by mass or more, even more preferably 0.3% by mass or more, and particularly preferably 0.5% by mass or more as the lower limit, and preferably 5.0% by mass or less, more preferably 4.0% by mass or less, even more preferably 3.0% by mass or less, and particularly preferably 2.0% by mass or less as the upper limit. When the content of these compounds is within the above range, it becomes easier to suppress the increase in resistance after the charge-discharge cycle.

[0083] (Compound represented by formula (IV)) This non-aqueous electrolyte may contain a compound represented by the following formula (IV).

[0084]

[0085] In formula (IV), Q represents a boron atom (B) or a phosphorus atom (P), and R ４１ 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; M ＋ Each of these independently represents an alkali metal ion, ammonium ion, imidazolium ion, pyridinium ion, pyrrolidinium ion, piperidinium ion, or phosphonium ion. When Q is a boron atom (B), a represents 1 or 2, b represents 2 when a is 1, and 0 when a is 2. When Q is a phosphorus atom (P), a represents an integer from 1 to 3, b represents 4 when a is 1, 2 when a is 2, and 0 when a is 3, and c represents an integer from 1 to 3.

[0086] Q represents either a boron atom (B) or a phosphorus atom (P). When Q is a boron atom, the compound represented by formula (IV) is a borate salt. When Q is a phosphorus atom, the compound represented by formula (IV) is a phosphate salt.

[0087] R ４１ Each of these independently represents either a "single bond (-)" or 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," but "single bond (-)" means R ４１ This means that the carbonyl groups (>C=O) at both ends are directly bonded, forming an oxalate ligand (oxalate ion ligand). Also, "divalent hydrocarbon group" means a hydrocarbon group with two bond positions. Furthermore, "may contain at least one functional group selected from the group consisting of halogen groups and oxa groups (-O-) as substituents" is synonymous with the above.

[0088] R ４１ When the group is a hydrocarbon group, the number of carbon atoms is preferably 5 or less, more preferably 4 or less, even more preferably 3 or less, and particularly preferably 2 or less.

[0089] R ４１ For example, a single bond (-), a methylene group (-CH ２ -), ethylene group (-CH ２ CH ２ -), n-propylene group (-CH ２ CH ２ CH ２ Examples include (-) and others. Among these, a single bond (-) is particularly preferred.

[0090] Each of the X groups independently represents a "halogeno group," specifically including a fluoro group (-F), a chloro group (-Cl), a bromo group (-Br), and an iodine group (-I). Among these, the fluoro group (-F) is particularly preferred.

[0091] M ＋This represents "alkali metal ions," "ammonium ions," "imidazolium ions," "pyridinium ions," "pyrrolidinium ions," "piperidinium ions," or "phosphonium ions," but is synonymous with the aforementioned. ＋ For example, lithium ion (Li ＋ It is especially preferable that it be of the following nature.

[0092] When Q is a boron atom (B), a represents 1 or 2, and b represents 2 when a is 1, and 0 when a is 2, but it is particularly preferable that a is 2, b is 0, and c is 1.

[0093] When Q is a phosphorus atom (P), a represents an integer from 1 to 3, b represents 4 when a is 1, 2 when a is 2, and 0 when a is 3, and c represents an integer from 1 to 3, but it is particularly preferable that a is 1, b is 4, and c is 1.

[0094] The compound represented by formula (IV) may be one or more selected from the group consisting of lithium bis(oxalato)borate (LiBOB) represented by formula (IV-1) below, lithium difluorooxalatoborate (LiDFOB) represented by formula (IV-2) below, lithium tetrafluorooxalatophosphate (LiTFOP) represented by formula (IV-3) below, and lithium difluorobis(oxalato)phosphate (LiDFBOP) represented by formula (IV-4) below. Note that this non-aqueous electrolyte may contain two or more compounds represented by formula (IV).

[0095]

[0096] In this non-aqueous electrolyte, the content of the compound represented by formula (IV) is usually 0.001% by mass or more and 10% 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). The lower limit is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, even more preferably 0.3% by mass or more, and particularly preferably 0.5% by mass or more. The upper limit is preferably 5.0% by mass or less, more preferably 4.0% by mass or less, even more preferably 3.0% by mass or less, and particularly preferably 2.0% by mass or less. When the content of these compounds is within the above range, it becomes easier to suppress the increase in resistance after the charge-discharge cycle.

[0097] (Compound represented by formula (V)) This non-aqueous electrolyte may contain a compound represented by the following formula (V).

[0098]

[0099] In formula (V), R ５１ 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, M ＋ This represents alkali metal ions, alkaline earth metal ions, ammonium ions, imidazolium ions, pyridinium ions, pyrrolidinium ions, piperidinium ions, or phosphonium ions.

[0100] R ５１ These terms independently represent "fluoro group (-F)", "fluorinated carbide group having 1 to 12 carbon atoms that may contain an oxa group (-O-) as a substituent", or "hydrocarbon group having 1 to 12 carbon atoms that contains a fluoro group (-F) as a substituent", but "fluorinated carbide group", etc., are synonymous with the above. Furthermore, "hydrocarbon group having 1 to 12 carbon atoms that contains a fluoro group (-F) as a substituent" means a hydrocarbon group in which one or more hydrogen atoms are substituted with fluorine atoms.

[0101] R ５１When R is a fluorine carbide group, the number of carbon atoms is preferably 10 or less, more preferably 8 or less, even more preferably 6 or less, and particularly preferably 4 or less. ５１ When the group is a hydrocarbon group, the number of carbon atoms is preferably 10 or less, more preferably 8 or less, even more preferably 6 or less, and particularly preferably 4 or less.

[0102] R ５１ 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), trifluoromethylphenyl group (-C ６ H ４ CF ３ ), trifluoromethoxyphenyl group (-C ６ H ４ OCF ３ Examples include the fluoro group (-F) and the trifluoromethyl group (-CF). ３ ) is particularly preferable.

[0103] M ＋This represents "alkali metal ions," "ammonium ions," "imidazolium ions," "pyridinium ions," "pyrrolidinium ions," "piperidinium ions," or "phosphonium ions," but is synonymous with the aforementioned. ＋ For example, lithium ion (Li ＋ It is especially preferable that it be of the following nature.

[0104] The compound represented by formula (V) may be one or more selected from the group consisting of lithium bis(fluorosulfonyl)imide (LiFSI) represented by formula (V-1) below, and lithium bis(trifluoromethylsulfonyl)imide (LiTFSI) represented by formula (V-2) below. Note that this non-aqueous electrolyte may contain two or more compounds represented by formula (V).

[0105]

[0106] The content of the compound represented by formula (V) in this non-aqueous electrolyte is usually 0.01% by mass or more and 30% 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), preferably 0.1% by mass or more as the lower limit, more preferably 0.2% by mass or more, even more preferably 0.3% by mass or more, and particularly preferably 0.5% by mass or more, and preferably 20.0% by mass or less as the upper limit, more preferably 10.0% by mass or less, even more preferably 5.0% by mass or less, and particularly preferably 2.0% by mass or less. When the content of these compounds is within the above range, it becomes easier to suppress the increase in resistance after the charge-discharge cycle.

[0107] (Compound represented by formula (VI)) This non-aqueous electrolyte may contain a compound represented by the following formula (VI).

[0108]

[0109] In formula (VI), R ６１ R represents a fluorine carbide group having 1 to 12 carbon atoms, which may contain a fluoro group (-F) or 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. ６２This 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 fluoro group (-F) and an oxa group (-O-) as a substituent, or a fluorine carbide group having 1 to 12 carbon atoms, which may contain an oxa group (-O-) as a substituent. ＋ This represents alkali metal ions, alkaline earth metal ions, ammonium ions, imidazolium ions, pyridinium ions, pyrrolidinium ions, piperidinium ions, or phosphonium ions.

[0110] R ６１ These terms independently represent "fluoro group (-F)", "a fluorine carbide group having 1 to 12 carbon atoms that may contain an oxa group (-O-) as a substituent", or "a hydrocarbon group having 1 to 12 carbon atoms that contains a fluoro group (-F) as a substituent", but "fluorine carbide group", etc. are synonymous with those mentioned above. Note that the oxa group (-O-) may be located at the terminal end of the fluorine carbide group or hydrocarbon group, for example, the sulfonyl group (>S (=O)) of formula (VI) ２ It is located at a position where it connects to R ６１ It may also be an alkoxy group (-OR; R is, for example, a hydrocarbon group having 1 to 11 carbon atoms).

[0111] R ６１ When R is a fluorine carbide group, the number of carbon atoms is preferably 10 or less, more preferably 8 or less, even more preferably 6 or less, and particularly preferably 4 or less. ６１ When the group is a hydrocarbon group, the number of carbon atoms is preferably 10 or less, more preferably 8 or less, even more preferably 6 or less, and particularly preferably 4 or less.

[0112] R ６１ 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), fluorophenyl group (-C ６ H ４ F), trifluoromethylphenyl group (-C ６ H ４ CF ３ Examples include the fluoro group (-F) and the trifluoromethyl group (-CF). ３ ) is particularly preferable.

[0113] R ６２ This represents a "carbonic group having 1 to 12 carbon atoms that 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," or a "fluorine carbide group having 1 to 12 carbon atoms that may contain an oxa group (-O-) as a substituent," but "hydrocarbon group," etc., are synonymous with those mentioned above. Note that the oxa group (-O-) may be located at the terminal end of the fluorine carbide group or hydrocarbon group, for example, at the position bonded to the carbonyl group (>C=O) of formula (IV), R ６２ It may also be an alkoxy group (-OR; R is, for example, a hydrocarbon group having 1 to 11 carbon atoms).

[0114] R ６２ When R is a hydrocarbon group, the number of carbon atoms is preferably 10 or less, more preferably 8 or less, even more preferably 6 or less, and particularly preferably 4 or less. ６２ When the group is a fluorine carbide group, the number of carbon atoms is preferably 10 or less, more preferably 8 or less, even more preferably 6 or less, and particularly preferably 4 or less.

[0115] R ６２ For example, a methoxy group (-OCH ３ ), ethoxy group (-OCH ２ CH ３ ), n-propoxy group (-OCH ２ CH ２ CH ３ ), t-butyroxy group (-OC(CH ３ ) ２ ), phenoxy group (-OC ６ H ５ ), fluorophenoxy group (-OC ６ H ４ F), trifluoromethylphenoxy group (-OC ６ H ４ CF ３ ), trifluoromethoxyphenoxy group (-OC ６ H ４ OCF ３ ), 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 ), 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), fluorophenyl group (-C ６ H ４ F), trifluoromethylphenyl group (-C ６ H ４ CF ３ ), trifluoromethoxyphenyl group (-C ６ H ４ OCF ３ ), trifluoromethoxy group (-OCF ３ ), pentafluoroethoxy group (-OC ２ F ５ ), n-heptafluoropropoxy group (-OC ３ F ７ ), pentafluorophenoxy group (-OC ６ F ５ ), trifluoromethyl group (-CF ３ ), pentafluoroethyl group (-C ２ F ５ ), n-heptafluoropropyl group (-C ３ F ７ ), pentafluorophenyl group (-C ６ F ５ Examples include the methoxy group (-OCH). ３ ), ethoxy group (-OCH ２ CH ３ ), n-propoxy group (-OCH ２ CH ２ CH ３ ) is particularly preferable.

[0116] The compound represented by formula (VI) can be one or more selected from the group consisting of lithium salts represented by formula (VI-1), formula (VI-2), formula (VI-3), formula (VI-4), etc. Note that this non-aqueous electrolyte may contain two or more compounds represented by formula (VI).

[0117]

[0118] In this non-aqueous electrolyte, the content of the compound represented by formula (VI) is usually 0.01% by mass or more and 5.0% 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 as 100% by mass). The lower limit is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, even more preferably 0.4% by mass or more, and particularly preferably 0.5% by mass or more. The upper limit is preferably 4.0% by mass or less, more preferably 3.0% by mass or less, even more preferably 2.0% by mass or less, and particularly preferably 1.0% by mass or less. When the content of these compounds is within the above range, it becomes easier to suppress the increase in resistance after the charge-discharge cycle.

[0119] (Compound represented by formula (VII)) This non-aqueous electrolyte may contain a compound represented by the following formula (VII).

[0120]

[0121] In formula (VII), R ７１ 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, M ＋ This represents alkali metal ions, alkaline earth metal ions, ammonium ions, imidazolium ions, pyridinium ions, pyrrolidinium ions, piperidinium ions, or phosphonium ions.

[0122] R ７１ These terms independently represent "fluoro group (-F)", "fluorine carbide group having 1 to 12 carbon atoms that may contain an oxa group (-O-) as a substituent", or "hydrocarbon group having 1 to 12 carbon atoms that contains a fluoro group (-F) as a substituent", but "fluorine carbide group", etc. are synonymous with the terms mentioned above.

[0123] R ７１ When R is a fluorine carbide group, the number of carbon atoms is preferably 10 or less, more preferably 8 or less, even more preferably 6 or less, and particularly preferably 4 or less. ７１When the group is a hydrocarbon group, the number of carbon atoms is preferably 10 or less, more preferably 8 or less, even more preferably 6 or less, and particularly preferably 4 or less.

[0124] R ７１ 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), fluorophenyl group (-C ６ H ４ F), trifluoromethylphenyl group (-C ６ H ４ CF ３ Examples include the fluoro group (-F) and the trifluoromethyl group (-CF). ３ ) is particularly preferable.

[0125] M ＋ This represents "alkali metal ions," "ammonium ions," "imidazolium ions," "pyridinium ions," "pyrrolidinium ions," "piperidinium ions," or "phosphonium ions," but is synonymous with the aforementioned. ＋ For example, lithium ion (Li ＋ It is especially preferable that it be of the following nature.

[0126] Compounds represented by formula (VII) include lithium fluorosulfonate (LiSO4), represented by the following formula (VII-1). ３ F), and lithium trifluoromethanesulfonate (LiSO2) represented by the following formula (VII-2). ３ CF ３ One or more compounds selected from the group consisting of the following are examples. Furthermore, this non-aqueous electrolyte may contain two or more compounds represented by formula (VII).

[0127]

[0128] The content of the compound represented by formula (VII) in this non-aqueous electrolyte is usually 0.01% by mass or more and 5.0% 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 as 100% by mass), preferably 0.1% by mass or more as the lower limit, more preferably 0.3% by mass or more, even more preferably 0.4% by mass or more, and particularly preferably 0.5% by mass or more, and preferably 4.0% by mass or less as the upper limit, more preferably 3.0% by mass or less, even more preferably 2.0% by mass or less, and particularly preferably 1.0% by mass or less. When the content of these compounds is within the above range, it becomes easier to suppress the increase in resistance after the charge-discharge cycle.

[0129] (Compound represented by formula (VIII)) This non-aqueous electrolyte may contain a compound represented by the following formula (VIII).

[0130]

[0131] In formula (VIII), R ８１ Each of these independently 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 may contain a fluoro group (-F) as a substituent, and j represents an integer from 1 to 4.

[0132] R ８１These terms independently represent "a fluorine carbide group having 1 to 12 carbon atoms that may contain an oxa group (-O-) as a substituent" or "a hydrocarbon group having 1 to 12 carbon atoms that contains a fluoro group (-F) as a substituent," but "fluorine carbide group," etc., are synonymous with the terms mentioned above.

[0133] R ８１ When R is a fluorine carbide group, the number of carbon atoms is preferably 10 or less, more preferably 8 or less, even more preferably 6 or less, and particularly preferably 4 or less. ８１ When the group is a hydrocarbon group, the number of carbon atoms is preferably 10 or less, more preferably 8 or less, even more preferably 6 or less, and particularly preferably 4 or less.

[0134] R ８１ For example, the trifluoromethyl group (-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), fluorophenyl group (-C ６ H ４ F), trifluoromethylphenyl group (-C ６ H ４ CF ３ Examples include the trifluoromethyl group (-CF ３ ) is particularly preferable.

[0135] j represents 1 through 4, but it is particularly preferable that it be 1.

[0136] The compound represented by formula (VIII) is one or more selected from the group consisting of trifluoropropylene carbonate (TFPC) represented by formula (VIII-1), a cyclic carbonate compound represented by formula (VIII-2), and a cyclic carbonate compound represented by formula (VIII-3). Note that this non-aqueous electrolyte may contain two or more compounds represented by formula (VIII).

[0137]

[0138] The content of the compound represented by formula (VIII) in this non-aqueous electrolyte is usually 0.01% by mass or more and 5.0% 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 as 100% by mass), preferably 0.1% by mass or more as the lower limit, more preferably 0.3% by mass or more, even more preferably 0.4% by mass or more, and particularly preferably 0.5% by mass or more, and preferably 4.0% by mass or less as the upper limit, more preferably 3.0% by mass or less, even more preferably 2.0% by mass or less, and particularly preferably 1.0% by mass or less. When the content of these compounds is within the above range, it becomes easier to suppress the increase in resistance after the charge-discharge cycle.

[0139] (Compound represented by formula (IX)) This non-aqueous electrolyte may contain a compound represented by the following formula (IX).

[0140]

[0141] In equation (IX), the solid and dotted double lines represent a single bond (-) or a double bond (=), R ９１ 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 may contain at least one functional group selected from the group consisting of a fluoro group and an oxa group (-O-) as a substituent, and k represents an integer from 0 to 4.

[0142] The solid and dotted double lines represent either a single bond (-) or a double bond (=). When there is a single bond (-), the compound represented by formula (IX) is a propensultone compound, and when there is a double bond (=), the compound represented by formula (IX) is a propensultone compound.

[0143] R ９１ These terms independently represent "fluoro group (-F)", "a fluorine carbide group having 1 to 12 carbon atoms that may contain an oxa group (-O-) as a substituent", or "a hydrocarbon group having 1 to 12 carbon atoms that may contain at least one functional group selected from the group consisting of a fluoro group and an oxa group (-O-) as a substituent", but "fluorine carbide group", etc. are synonymous with the above.

[0144] R ９１ When R is a fluorine carbide group, the number of carbon atoms is preferably 10 or less, more preferably 8 or less, even more preferably 6 or less, and particularly preferably 4 or less. ９１ When the group is a hydrocarbon group, the number of carbon atoms is preferably 10 or less, more preferably 8 or less, even more preferably 6 or less, and particularly preferably 4 or less.

[0145] R ９１ 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 (-CH２ 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 ), trifluoromethoxyphenyl group (-C ６ H ４ OCF ３ Examples include the fluoro group (-F) and the trifluoromethyl group (-CF). ３ ) is particularly preferable.

[0146] k represents an integer between 0 and 4, but it is particularly preferable that it be 0 or 1.

[0147] The compound represented by formula (IX) is one or more selected from the group consisting of 1,3-propanesultone (PS) represented by formula (IX-1), sultone represented by formula (IX-2), sultone represented by formula (IX-3), sultone represented by formula (IX-4), 1-propene-1,3-sultone (PRS) represented by formula (IX-5), sultone represented by formula (IX-6), sultone represented by formula (IX-7), and sultone represented by formula (IX-8). Note that this non-aqueous electrolyte may contain two or more compounds represented by formula (IX).

[0148]

[0149] The content of the compound represented by formula (IX) in this non-aqueous electrolyte is usually 0.01% by mass or more and 5.0% 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), preferably 0.1% by mass or more as the lower limit, more preferably 0.3% by mass or more, even more preferably 0.4% by mass or more, and particularly preferably 0.5% by mass or more, and preferably 4.0% by mass or less as the upper limit, more preferably 3.0% by mass or less, even more preferably 2.0% by mass or less, and particularly preferably 1.0% by mass or less. When the content of these compounds is within the above range, it becomes easier to suppress the increase in resistance after the charge-discharge cycle.

[0150] (Compound represented by formula (X-1) and compound represented by the following formula (X-2)) This non-aqueous electrolyte may contain at least one compound selected from the group consisting of the compound represented by the following formula (X-1) and the compound represented by the following formula (X-2).

[0151]

[0152] In equations (X-1) and (X-2), R １０１ and R １０２ 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 R 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 ) １０３These 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 ).

[0153] R １０１ and R １０２ These are, independently, "a halogen group, an oxa group (-O-), a carbonyl group (>C=O), and a sulfonyl group (>S(=O)" as substituents. ２ This refers to a divalent hydrocarbon group having 1 to 6 carbon atoms, which may contain at least one functional group selected from the group consisting of the above, but "divalent hydrocarbon group," etc., are synonymous with the above.

[0154] R １０１ The number of carbon atoms in the hydrocarbon group is preferably 5 or less, more preferably 4 or less, even more preferably 3 or less, and particularly preferably 2 or less. １０２ The number of carbon atoms in the hydrocarbon group is preferably 5 or less, more preferably 4 or less, even more preferably 3 or less, and particularly preferably 2 or less.

[0155] R １０１ For example, the methylene group (-CH ２ -), ethylene group (-CH ２ CH ２ -), n-propylene group (-CH ２ CH ２ CH ２ -), n-butylene group (-CH ２ CH ２ CH ２ CH ２ Examples include methylene groups (-CH ２ -) is particularly preferable. R １０２ For example, the methylene group (-CH ２ -), ethylene group (-CH ２ CH ２ -), n-propylene group (-CH ２ CH ２ CH ２ -), n-butylene group (-CH ２ CH ２ CH２ CH ２ Examples include methylene groups (-CH ２ -) is particularly preferable.

[0156] R １０３ Each of these groups independently has a halogen group, a cyano group (-CN), an oxa group (-O-), a carbonyl group (>C=O), and a sulfonyl group (>S(=O)) as substituents. ２ This term 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 above, but "hydrocarbon group," etc., are synonymous with the above.

[0157] R １０３ The number of carbon atoms in the hydrocarbon group is preferably 10 or less, more preferably 8 or less, even more preferably 6 or less, and particularly preferably 4 or less.

[0158] R １０３ 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 Examples include:

[0159] The compounds represented by formula (X-1) and formula (X-2) include one or more selected from the group consisting of methylene methane disulfonate (MMDS) represented by the following formula (X-1-1) and disulfonic acid esters represented by the following formula (X-2-1). Note that this non-aqueous electrolyte 1 may also contain two or more compounds selected from the group consisting of compounds represented by formula (X-1) and compounds represented by formula (X-2).

[0160]

[0161] The content of the compound represented by formula (X-1) and the compound represented by formula (X-2) in this non-aqueous electrolyte is usually 0.001% by mass or more and 5.0% 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), preferably 0.01% by mass or more as the lower limit, more preferably 0.1% by mass or more, even more preferably 0.3% by mass or more, and particularly preferably 0.5% by mass or more as the lower limit, and preferably 4.0% by mass or less, more preferably 3.0% by mass or less, even more preferably 2.0% by mass or less, and particularly preferably 1.5% by mass or less as the upper limit. When the content of these compounds is within the above range, it becomes easier to suppress the increase in resistance after the charge-discharge cycle.

[0162] (Compound represented by formula (XI)) This non-aqueous electrolyte may contain the compound represented by the following formula (XI).

[0163]

[0164] In formula (XI), R １１１ This represents an m+1 valent hydrocarbon group having 1 to 24 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, where m is an integer from 0 to 4.

[0165] R １１１The expression represents "an m+1 valent hydrocarbon group having 1 to 24 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," where "m+1 valent hydrocarbon group" means a hydrocarbon group having m+1 bond positions. Also, m represents an integer from 0 to 4, meaning that the compound represented by formula (XI) is a compound having 1 to 5 isocyanate groups, such as a monoisocyanate compound, diisocyanate compound, or triisocyanate compound.

[0166] R １１１ The number of carbon atoms in the hydrocarbon group is preferably 20 or less, more preferably 16 or less, even more preferably 12 or less, and particularly preferably 10 or less.

[0167] R １１１ For example, the methylene group (-CH ２ -), ethylene group (-CH ２ CH ２ -), n-propylene group (-CH ２ CH ２ CH ２ -), n-butylene group (-CH ２ CH ２ CH ２ CH ２ -), n-pentylene group (-CH ２ CH ２ CH ２ CH ２ CH ２ -), methylene group (-CH ２ -), phenylene group (-C ６ H ４ Examples include: -)

[0168] m represents an integer between 0 and 4, but it is preferably 1.

[0169] The compound represented by formula (XI) can be one or more selected from the group consisting of the compound represented by formula (XI-1), the compound represented by formula (XI-2), the compound represented by formula (XI-3), the compound represented by formula (XI-4), the compound represented by formula (XI-5), the compound represented by formula (XI-6), and the compound represented by formula (XI-7). The non-aqueous electrolyte may contain two or more compounds represented by formula (XI).

[0170]

[0171] The content of the compound represented by formula (XI) in this non-aqueous electrolyte is usually 0.01% by mass or more and 5.0% 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), preferably 0.1% by mass or more as the lower limit, more preferably 0.3% by mass or more, even more preferably 0.4% by mass or more, and particularly preferably 0.5% by mass or more, and preferably 4.0% by mass or less as the upper limit, more preferably 3.0% by mass or less, even more preferably 2.0% by mass or less, and particularly preferably 1.0% by mass or less. When the content of these compounds is within the above range, it becomes easier to suppress the increase in resistance after the charge-discharge cycle.

[0172] (Compound represented by formula (XII)) This non-aqueous electrolyte may contain the compound represented by the following formula (XII).

[0173]

[0174] In formula (XII), R １２１ This represents an n+1 valent hydrocarbon group having 1 to 24 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, where n is an integer from 0 to 4.

[0175] R １２１This represents "an n+1 valent hydrocarbon group having 1 to 24 carbon atoms, which may contain at least one functional group selected from the group consisting of halogen groups and oxa groups (-O-) as substituents," where "n+1 valent hydrocarbon group" means a hydrocarbon group having n+1 bond positions. Also, n represents an integer from 0 to 4, meaning that the compound represented by formula (XII) is a compound having 1 to 5 cyano groups, such as a monocyano compound, dicyano compound, or tricyano compound.

[0176] R １２１ The number of carbon atoms in the hydrocarbon group is preferably 20 or less, more preferably 16 or less, even more preferably 12 or less, and particularly preferably 10 or less.

[0177] R １２１ For example, the methylene group (-CH ２ -), ethylene group (-CH ２ CH ２ -), n-propylene group (-CH ２ CH ２ CH ２ -), n-butylene group (-CH ２ CH ２ CH ２ CH ２ -), n-pentylene group (-CH ２ CH ２ CH ２ CH ２ CH ２ -), methylene group (-CH ２ -), phenylene group (-C ６ H ４ Examples include: -)

[0178] n represents an integer between 0 and 4, but it is preferably 1.

[0179] The compound represented by formula (XII) is one or more selected from the group consisting of adiponitrile represented by formula (XII-1), the compound represented by formula (XII-2), the compound represented by formula (XII-3), the compound represented by formula (XII-4), and the compound represented by formula (XII-5). The non-aqueous electrolyte may contain two or more compounds represented by formula (XII).

[0180]

[0181] The content of the compound represented by formula (XII) in this non-aqueous electrolyte is usually 0.01% by mass or more and 5.0% 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 as 100% by mass), preferably 0.1% by mass or more as the lower limit, more preferably 0.3% by mass or more, even more preferably 0.4% by mass or more, and particularly preferably 0.5% by mass or more, and preferably 4.0% by mass or less as the upper limit, more preferably 3.0% by mass or less, even more preferably 2.0% by mass or less, and particularly preferably 1.0% by mass or less. When the content of these compounds is within the above range, it becomes easier to suppress the increase in resistance after the charge-discharge cycle.

[0182] (Compound represented by formula (XIII)) This non-aqueous electrolyte may contain the compound represented by the following formula (XIII).

[0183]

[0184] In formula (XIII), R １３１ is a methylene group (-CH ２ -), ethylene group (-CH ２ CH ２ -), or n-propylene group (-CH ２ CH ２ CH ２ -) represents R １３２ Each independently represents a hydrocarbon group having 1 to 6 carbon atoms, a group represented by formula (xiiii-3), a group represented by formula (xiiii-4), a group represented by formula (xiiii-5), a group represented by formula (xiiii-6), a group represented by formula (xiiii-7), or a group represented by formula (xiiii-8), which may each contain at least one functional group selected from the group consisting of a halogen group (-X) and an oxa group (-O-) as a substituent, and p is R １３１ is a methylene group (-CH ２ When -, an integer from 0 to 2, R １３１ is an ethylene group (-CH ２ CH ２ When -, an integer from 0 to 4, R １３１ is an n-propylene group (-CH ２ CH２ CH ２ When it is -, it represents an integer from 0 to 6.

[0185] R １３１ This is a methylene group (-CH ２ -) ``Ethylene group (-CH ２ CH ２ -) or "n-propylene group (-CH ２ CH ２ CH ２ It represents the ethylene group (-CH ２ CH ２ -), n-propylene group (-CH ２ CH ２ CH ２ -) is preferred, and the ethylene group (-CH) ２ CH ２ -) is particularly preferable.

[0186] R １３２ Each of these independently represents "a 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 (-X) and an oxa group (-O-) as a substituent," "a group represented by formula (xiiii-3)," "a group represented by formula (xiiii-4)," "a group represented by formula (xiiii-5)," "a group represented by formula (xiiii-6)," "a group represented by formula (xiiii-7)," or "a group represented by formula (xiiii-8)," but "hydrocarbon group," etc., are synonymous with those mentioned above.

[0187] In equations (xiiii-3), (xiiii-4), (xiiii-5), (xiiii-6), (xiiii-7), and (xiiii-8), the dashed line has R at the end of the dashed line. １３１ 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 the hydrogen atom. Note that the two wavy lines in (xiii-8) have R at the end of each line. １３１ The methylene group (-CH ２ -) ``Ethylene group (-CH２ CH ２ -) or "n-propylene group (-CH ２ CH ２ CH ２ The dashed line indicates that it is bonded as a substituent to a hydrogen atom, and for example, the ends of the two dashed lines are R １３１ It is acceptable for the atom to be bonded to the same carbon atom or to different carbon atoms.

[0188] R １３２ When it is a hydrocarbon group, the number of carbon atoms is preferably 5 or less, more preferably 4 or less.

[0189] R １３２ 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 ), trifluoromethoxyphenyl group (-C ６ H ４ OCF３ Examples include the group represented by formula (xiiii-3), the group represented by formula (xiiii-4), the group represented by formula (xiiii-5), the group represented by formula (xiiii-6), the group represented by formula (xiiii-7), and the group represented by formula (xiiii-8). Among these, the n-propyl group (-CH ２ CH ２ CH ３ ), a group represented by formula (x-3) is particularly preferred.

[0190] p is R １３１ is a methylene group (-CH ２ When -, an integer from 0 to 2, R １３１ is an ethylene group (-CH ２ CH ２ When -, an integer from 0 to 4, R １３１ is an n-propylene group (-CH ２ CH ２ CH ２ When it is -, it represents an integer from 0 to 6, but it is particularly preferable that it be 0 or 1.

[0191] The compound represented by formula (XIII) is one or more selected from the group consisting of 1,3,2-dioxathione 2,2-dioxide (DTD) represented by formula (XIII-1), sulfate ester represented by formula (XIII-2), sulfate ester represented by formula (XIII-3), sulfate ester represented by formula (XIII-4), sulfate ester represented by formula (XIII-5), sulfate ester represented by formula (XIII-6), sulfate ester represented by formula (XIII-7), and sulfate ester represented by formula (XIII-8). Note that this non-aqueous electrolyte may contain two or more compounds represented by formula (XIII).

[0192]

[0193] The content of the compound represented by formula (XIII) in this non-aqueous electrolyte is usually 0.01% by mass or more and 5.0% 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 as 100% by mass), preferably 0.1% by mass or more as the lower limit, more preferably 0.3% by mass or more, even more preferably 0.4% by mass or more, and particularly preferably 0.5% by mass or more, and preferably 4.0% by mass or less as the upper limit, more preferably 3.0% by mass or less, even more preferably 2.0% by mass or less, and particularly preferably 1.0% by mass or less. When the content of these compounds is within the above range, it becomes easier to suppress the increase in resistance after the charge-discharge cycle.

[0194] The non-aqueous electrolyte preferably contains a first component (hereinafter sometimes abbreviated as "first component") which is one or more compounds selected from the group consisting of compounds represented by formula (I) and compounds represented by formula (II), and a second component (hereinafter sometimes abbreviated as "second component") which is one or more compounds selected from the group consisting of compounds represented by formula (III-1), compounds represented by formula (III-2), compounds represented by formula (IV), compounds represented by formula (V), compounds represented by formula (VI), compounds represented by formula (VII), compounds represented by formula (VIII), compounds represented by formula (IX), compounds represented by formula (X-1), compounds represented by formula (X-2), compounds represented by formula (XI), compounds represented by formula (XII), and compounds represented by formula (XIII).

[0195] The total content of the first component in this non-aqueous electrolyte is usually 0.0001% to 10% 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), preferably 0.1% by mass or more as the lower limit, more preferably 0.3% by mass or more, even more preferably 0.6% by mass or more, and particularly preferably 0.9% by mass or more, and preferably 9.0% by mass or less as the upper limit, more preferably 8.0% by mass or less, even more preferably 7.0% by mass or less, and particularly preferably 6.0% by mass or less. When the content of these compounds is within the above range, it becomes easier to suppress the increase in resistance after the charge-discharge cycle.

[0196] The total content of the second component in this non-aqueous electrolyte is usually 0.0001% 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 as 100% by mass), preferably 0.1% by mass or more, more preferably 0.3% by mass or more, even more preferably 0.6% by mass or more, and particularly preferably 0.9% by mass or more as the lower limit, preferably 10.0% by mass or less, more preferably 5.0% by mass or less, even more preferably 4.0% by mass or less, and particularly preferably 2.0% by mass or less as the upper limit. When the content of these compounds is within the above range, it becomes easier to suppress the increase in resistance after the charge-discharge cycle.

[0197] (Non-aqueous solvent) 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.

[0198] 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, sulfolane, 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 chain 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 lactams include N-methylpyrrolidinone, N-methyloxazolidinone, and N,N'-dimethylimidazolidinone.

[0199] 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% by mass or more and 100% by mass or less, more preferably 60% by mass or more and 100% by mass or less, and even more preferably 80% by mass or more and 100% by mass or less, based on the total amount of the non-aqueous solvent.

[0200] 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 in the non-aqueous solvent is preferably 50% by mass or more and 100% by mass or less, more preferably 60% by mass or more and 100% by mass or less, and even more preferably 80% by mass or more and 100% by mass or less, based on the total amount of the non-aqueous solvent.

[0201] The upper limit of the non-aqueous solvent content is preferably 99% by mass, preferably 97% by mass, and more preferably 90% by mass, relative to the total amount of the non-aqueous electrolyte. The lower limit of 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.

[0202] 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.

[0203] (Electrolytes) Non-aqueous electrolytes generally contain electrolytes.

[0204] 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.

[0205] Examples of fluorinated lithium salts include inorganic acid anionic salts and organic acid anionic salts. An example of an inorganic acid anionic salt is lithium hexafluoride phosphate (LiPF). ６ ), lithium tetrafluoroborate (LiBF ４ ), lithium hexafluoride arsenate (LiAsF ６ ), 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.

[0206] Lithium salts that do not contain fluorine include lithium perchlorate (LiClO2). ４ ), lithium aluminum tetrachloride (LiAlCl ４ ), lithium decachlorodecaborate (Li ２ B １０ Cl １０ ) are some examples.

[0207] 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 ratio of ) is preferably 50% by mass or more and 100% by mass or less, more preferably 60% by mass or more and 100% by mass or less, and even more preferably 80% by mass or more and 100% by mass or less, relative to the total amount of electrolyte.

[0208] When the non-aqueous electrolyte contains an electrolyte, the concentration of the electrolyte in the non-aqueous electrolyte is preferably 0.1 mol / L or more and 3 mol / L or less, more preferably 0.5 mol / L or more and 2 mol / L or less.

[0209] 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 or more and 3 mol / L or less, more preferably 0.5 mol / L or more and 2 mol / L or less.

[0210] <Positive Electrode> A positive electrode can usually be manufactured by dispersing a positive electrode active material, a binder, and optionally a conductive additive and a thickener in a solvent to form a slurry, applying this slurry to a current collector, drying it, and compressing it to form a positive electrode composite layer (also called the "positive electrode active material layer") on the current collector. The "positive electrode active material," "binder," "current collector," etc. will be described in detail below.

[0211] (Positive electrode active material) The positive electrode active material is 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 O２ LiNi ０．８ Co ０．１ Mn ０．１ O ２ Composite 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; 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.

[0212] The total content of the positive electrode active material in the positive electrode composite layer is usually 70% to 99% by mass, but preferably 75% or more by mass, and preferably 98% or less by mass, when the total content of the positive electrode composite layer is taken as 100% by mass.

[0213] (Binding agent) Examples of binders for the positive electrode include polyvinylidene fluoride, and examples of conductive additives for the positive electrode include carbon black (e.g., acetylene black), amorphous whiskers, and graphite, while examples of thickeners for the positive electrode include carboxymethylcellulose. In addition, examples of organic solvents for the slurry used to form the positive electrode include N-methylpyrrolidone.

[0214] (Current Collector) Examples of materials for the positive electrode current collector include aluminum, aluminum alloy, stainless steel, nickel, titanium, tantalum, carbon cloth, and carbon paper.

[0215] <Separator> A porous resin plate can be used as a separator. The material of the porous resin plate can be a resin, a nonwoven fabric containing this resin, etc. Examples of resins include polyethylene (PE), polypropylene (PP), polymethylpentene (PMP), polyester, cellulose, and polyamide. In particular, 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 one or more types of polyolefin resins. 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.

[0216] <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 described herein. Examples of cases include cases including a laminate film, and cases consisting of a battery can and a battery can lid.

[0217] [Lithium Secondary Battery] The non-aqueous electrolyte secondary battery of the present disclosure described above is preferably a lithium secondary battery. Specific examples of lithium secondary battery precursors that can produce a lithium secondary battery, and methods for producing a lithium secondary battery, are described below. In this disclosure, "secondary battery precursor" means a secondary battery before charging and discharging after manufacturing. For example, "non-aqueous electrolyte secondary battery precursor" and "lithium secondary battery precursor" mean a non-aqueous electrolyte secondary battery and a lithium secondary battery, respectively, before charging and discharging after manufacturing. Furthermore, the lithium secondary battery, which is a non-aqueous electrolyte secondary battery of this disclosure, and its precursor are also referred to as "lithium secondary battery of this disclosure" and "lithium secondary battery precursor of this disclosure," respectively.

[0218] <Specific Examples of Lithium Secondary Battery Precursors> Figure 1 is a schematic cross-sectional view showing a stacked lithium secondary battery precursor, which is an example of a lithium secondary battery precursor according to this disclosure.

[0219] As shown in Figure 1, the lithium secondary battery precursor 1 is a stacked battery precursor. More specifically, in the lithium secondary battery precursor 1, the battery element 10 is enclosed inside an outer casing 30. The outer casing 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 outer casing 30.

[0220] 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.

[0221] The above-mentioned non-aqueous electrolyte is injected into the outer casing 30 of the lithium secondary battery precursor 1. The above-mentioned non-aqueous electrolyte permeates the positive electrode composite layer 11B, the separator 13, and the negative electrode composite layer 12B. In the lithium secondary battery precursor 1, one single cell layer 14 is formed by the adjacent positive electrode composite layer 11B, the separator 13, and the negative electrode composite layer 12B. The positive electrode and negative electrode may be formed with the respective active material layers on one side of each current collector. The above-mentioned non-aqueous electrolyte contains one or more compounds selected from the group consisting of compounds represented by the above-mentioned formula (I), and the above-mentioned negative electrode active material contains the above-mentioned Si-C particles.

[0222] Although lithium secondary battery precursor 1 is a stacked lithium secondary battery precursor, the lithium secondary battery precursor of this disclosure is not limited to this, and may be, for example, a wound lithium secondary battery precursor. The wound lithium secondary battery precursor is formed by stacking a positive electrode, a separator, a negative electrode, and a separator in that order and winding them in layers. The wound lithium secondary battery precursor includes cylindrical lithium secondary battery precursors and prismatic lithium secondary battery precursors.

[0223] As shown in Figure 1, in the lithium secondary battery precursor 1, the directions in which the positive electrode lead and the negative electrode lead protrude from the inside to the outside of the outer casing 30 are opposite to the outer casing 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 outer casing 30 is the same direction with respect to the outer casing 30.

[0224] An example of the lithium secondary battery of this disclosure described later is a lithium secondary battery obtained by subjecting a lithium secondary battery precursor 1 to charging and discharging.

[0225] Figure 2 is a schematic cross-sectional view showing a coin-type lithium secondary battery precursor, which is another example of a lithium secondary battery precursor of the present disclosure.

[0226] In the coin-type lithium secondary battery precursor shown in Figure 2, a disc-shaped negative electrode 42, a separator 45 injected with a non-aqueous electrolyte, 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 a positive electrode can 43 (hereinafter also referred to as the "battery can") and a 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 injected into the separator 45 is a non-aqueous electrolyte containing one or more compounds selected from the group consisting of compounds represented by the aforementioned formula (I). Furthermore, the negative electrode active material contained in the disc-shaped negative electrode 42 is a negative electrode active material containing the aforementioned Si-C particles.

[0227] An example of the lithium secondary battery of this disclosure, as described later, is a lithium secondary battery obtained by charging and discharging a coin-type lithium secondary battery precursor shown in Figure 2.

[0228] <Method for Manufacturing a Lithium Secondary Battery> The method for manufacturing a lithium secondary battery according to the present disclosure includes the steps of preparing the lithium secondary battery precursor described above (hereinafter also referred to as the "preparation step") and the steps of charging and discharging the lithium secondary battery precursor. The lithium secondary battery according to the present disclosure may be a lithium secondary battery obtained by charging and discharging the lithium secondary battery precursor described above.

[0229] According to the lithium secondary battery and its manufacturing method disclosed herein, it is possible to suppress the increase in resistance after the charge-discharge cycle of the lithium secondary battery.

[0230] The preparation step may simply be a step of preparing a pre-manufactured lithium secondary battery precursor of the present disclosure for use in the charging and discharging process, or it may be a step of manufacturing the lithium secondary battery precursor of the present disclosure. The lithium secondary battery precursor is as described above.

[0231] In the charging and discharging process, the charging and discharging of the lithium 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 lithium secondary battery precursor. As described above, this charging and discharging preferably forms an SEI (Solid Electrolyte Interface) film on the surface of the positive electrode (particularly the positive electrode active material) and / or the negative electrode (particularly the negative electrode active material) of the lithium secondary battery precursor.

[0232] The charging and discharging process preferably involves performing a combination of charging and discharging on the lithium secondary battery precursor one or more times in an environment of 25°C to 70°C.

[0233] The method for manufacturing a lithium secondary battery according to this disclosure may include steps other than the preparation steps and charging and discharging steps described above.

[0234] 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.

[0235] <Preparation of Si-C Particles 1, 2, and 3> Si-C Particles 1, 2, and 3, each having the physical properties described in Table 1 below, were obtained. Si-C Particle 1 is SiC-1900 manufactured by Xi'an Shaanmei Qingjiu Xin Energy Technology Co., Ltd., and is a type of porous carbon-derived particle in which porous carbon forms C domains, and Si domains are formed on at least one surface inside and outside the pores of the porous carbon. Si-C Particle 2 is SiC-1800 manufactured by Xi'an Shaanmei Qingjiu Xin Energy Technology Co., Ltd., and is a type of silicon-carbon composite particle in which particles containing silicon components form Si domains, and C domains are formed between the silicon-containing particles. Si-C Particle 3 is silicon oxide particle (SiO ｘ (x=1), disproportionate Si + SiO ２ It is also possible that this is the case.) It is a type of particle in which a Si domain is formed and a C domain is formed between silicon oxide particles.

[0236]

[0237] <Micro-Raman Spectroscopy Measurement of Si-C Particles> Micro-Raman spectroscopy measurements were performed on each of the Si-C particles (1, 2, and 3), mainly at 1450 cm⁻¹. －１ ~1700cm －１ Maximum peak intensity I Ｇ , 1200cm －１ ~1450cm －１ Maximum peak intensity I Ｄ , 450cm －１ ~600cm －１ Maximum peak intensity I Ｓｉ Observations were performed. The measurements were taken by placing the sample on a glass slide, flattening it, and mapping using a micro-Raman system (JASCO NRS-5100). The stage movement interval was 5 μm steps (X: 11 points, Y: 11 points, total 121 points). Representative Raman spectra for each Si-C particle are shown in Figure 3.

[0238] 1450cm －１ ~1700cm －１ Maximum peak intensity I Ｇ , 1200cm －１ ~1450cm－１ Maximum peak intensity I Ｄ , 450cm －１ ~600cm －１ Maximum peak intensity I Ｓｉ These were calculated using the baseline method. Note that the maximum peak intensity I Ｓｉ For this, the peak intensity at the wavenumber where the peak intensity is maximum was calculated. Ｇ I Ｓｉ Ratio I Ｓｉ / I Ｇ The average value and I Ｇ I Ｄ Ratio I Ｄ / I Ｇ The average values ​​and are shown in Table 2.

[0239]

[0240] <X-ray fluorescence analysis (XRF) measurement of Si-C particles> For each of Si-C particle 1, Si-C particle 2, and Si-C particle 3, the carbon content m was determined by X-ray fluorescence analysis (XRF). Ｃ，ＸＲＦ [mass%], oxygen content m Ｏ，ＸＲＦ [Mass %] and silicon content m Ｓｉ，ＸＲＦ [Mass %] etc. were measured. For the measurement, the sample was placed in a polyvinyl chloride ring and pressed (conditions: 10 MPa, 3 minutes) to form a tablet, and the formed sample was quantitatively analyzed by the FP method using a wavelength-dispersive XRF (Rigaku ZSX Primus IV). The results and the ratios calculated from these results were measured. Ｓｉ，ＸＲＦ / m Ｏ，ＸＲＦ These are shown in Table 3.

[0241] <TEM-EELS Measurement of Si-C Particle 1> After applying a Pt coating to Si-C particle 1 using an ion sputtering apparatus E-1030 (manufactured by Hitachi High-Technologies Corporation), carbon was deposited using a vacuum deposition apparatus SVC-700 (manufactured by Sanyu Electronics Co., Ltd.). Subsequently, Pt deposition was performed using a focused ion beam (FIB) processing apparatus Helios G4UX (manufactured by FE-I Japan), followed by FIB cross-sectional processing and thinning. Electron energy loss spectroscopy (EELS) measurements were then performed using a field emission transmission electron microscope (FE-TEM) JEM-ARM200F (manufactured by JEOL Ltd.). A GIF QUANTUM ER (manufactured by Gatan) was used as the detector. The EELS spectrum is shown in Figure 4. From the spectrum in Figure 4, it was confirmed that the silicon component of the Si domain in Si-C particle 1 is mainly in the state of unoxidized (metallic) silicon.

[0242] <Total Si content of Si-C particles, Si content derived from metallic Si, SiO ２ Derived Si content, SiO ２ Measurement of quantity > For each of Si-C particle 1, Si-C particle 2, and Si-C particle 3, HNO ３ By adding HF, metallic Si and SiO in Si-C particles ２ After dissolving the compound, the solution was diluted to a fixed volume with pure water, allowed to stand overnight, filtered, and diluted to obtain the test solution. The total amount of Si in the Si-C particles (mSi(total), ICP[mass%]) was quantified by inductively coupled plasma atomic emission spectroscopy (ICP-AES), with the mass of the Si-C particles set to 100. The total amount of Si includes the amount of Si derived from metallic Si and SiO ２ The amount of Si derived from it is included. Next, HF is added to each of Si-C particle 1, Si-C particle 2, and Si-C particle 3, so that the SiO in Si-C is reduced. ２ After dissolving the compound, it was diluted to a fixed volume with pure water, left to stand overnight, filtered, and diluted to obtain the test solution. The SiO2 was then measured using ICP-AES, with the mass of Si-C particles set to 100. ２The amount of Si derived from mSi(SiO2), ICP [mass%] was quantified. Furthermore, the total amount of Si (mSi(total), ICP [mass%]) and SiO2 were also quantified. ２ The difference in the amount of Si derived was defined as the amount of Si derived from metallic Si, mSi(Si), ICP [mass%]. ２ The amount of Si derived from mSi(SiO2), ICP [mass%] is calculated using the atomic weight of Si (28.09) and SiO2. ２ Based on the molecular weight of 60.08, SiO ２ The amount is calculated, and the SiO in the Si-C particles ２ The quantity was used. These results are shown in Table 4. SiO ２ Amount=SiO ２ Derived Si content mSi(SiO2), ICP [mass%] × 60.08 / 28.09

[0243]

[0244] [Example 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 in a volume ratio of EC:DMC:EMC = 30:35:35. This obtained a mixed solvent as a non-aqueous solvent. LiPF was added to the obtained mixed solvent as an electrolyte. ６ The following was prepared by dissolving the following in an electrolyte solution such that the concentration in the final non-aqueous electrolyte solution was 1 mol / L, thereby obtaining an electrolyte solution (hereinafter sometimes abbreviated as "basic electrolyte solution"). To the obtained basic electrolyte solution, vinylene carbonate (VC) represented by the following formula (I-1) and fluoroethylene carbonate (FEC) represented by the following formula (II-1) were added, respectively, so that their respective content relative to the total amount of the final non-aqueous electrolyte solution (values ​​when the total amount of the non-aqueous electrolyte solution is considered as 100% by mass) was as shown in Table 5, thereby obtaining a non-aqueous electrolyte solution.

[0245]

[0246] <Fabrication of the positive electrode> Li(Ni) as the positive electrode active material ０．８ Co ０．１ Mn ０．１ O ２A mixture was obtained by adding 94% by mass of (94% by mass) 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 coated onto the aluminum foil, dried, and then 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 active material layer.

[0247] <Preparation of the negative electrode> A negative electrode slurry was obtained by mixing graphite (86.4% by mass) as the negative electrode active material, the aforementioned Si-C particles 1 (9.6% by mass, 10% by mass when the total negative electrode active material is considered as 100% by mass), carbon black (1% by mass) as a conductive additive, 1% by mass of carboxymethylcellulose sodium dispersed in pure water as a thickener, and 2% by mass of styrene-butadiene rubber (SBR) dispersed in pure water 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, dried, and then 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 active material layer.

[0248] <Preparation of the separator> A porous polyethylene film was prepared as the separator.

[0249] <Preparation of Non-Aqueous Electrolyte Secondary Battery Precursor> The negative electrode was punched out in a disc shape with a diameter of 14 mm, the positive electrode in a disc shape with a diameter of 13 mm, and the separator in a disc shape with a diameter of 17 mm. This yielded coin-shaped negative electrode, coin-shaped positive electrode, and 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 size). Next, 20 μL of non-aqueous electrolyte was poured into the battery case, impregnating the separator, positive electrode, and negative electrode with 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-type non-aqueous electrolyte secondary battery precursor (i.e., a non-aqueous electrolyte secondary battery before charging and discharging; in this embodiment, specifically, a lithium secondary battery precursor) 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.

[0250] <Preparation of Non-Aqueous Electrolyte Secondary Battery> The above 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 (specifically, a lithium secondary battery in this embodiment).

[0251] <Evaluation of Initial Room Temperature Resistance (25°C)> A non-aqueous electrolyte secondary battery was charged to 3.7V, and then, under room temperature conditions (25°C in this disclosure), the DC resistance [Ω] as the initial room temperature charging resistance (25°C) was measured based on the voltage rise (= voltage at 10 seconds after the start of charging - voltage before the start of charging) and the current value (i.e., the current value corresponding to the charging rates of 0.1C to 1.0C) for each of the "CC 10s charging" cycles at each of the charging rates of 0.1C to 1.0C. Next, the DC resistance [Ω] as the initial room temperature discharge resistance (25°C) was measured based on the voltage drop (= voltage before the start of discharge - voltage at 10 seconds after the start of discharge) and the current value (i.e., the current value corresponding to the discharge rates of 0.1C to 1.0C) for each of the "CC 10s discharge" cycles at each of the discharge rates of 0.1C to 1.0C.

[0252] <Charge-Discharge Cycle Test> A non-aqueous electrolyte secondary battery was charged to 4.2V using CC-CV charging at a temperature of 25°C with a current of 0.5C, and then discharged to 2.5V using CC charging. The discharge capacity at this point was defined as the initial capacity. The same procedure was repeated 100 times.

[0253] <Evaluation of Resistance Values ​​in Charge-Discharge Cycle Tests> The room temperature charge DCR (25°C) of the non-aqueous electrolyte secondary battery after the charge-discharge cycle test was measured in the same way as the initial charge DCR (25°C). The relative value of the room temperature charge resistance after the charge-discharge cycle, with the initial room temperature charge resistance of Example 1 set to 100, was defined as the room temperature charge resistance increase rate. Furthermore, the room temperature discharge DCR (25°C) of the non-aqueous electrolyte secondary battery after the charge-discharge cycle test was measured in the same way as the initial charge DCR (25°C). The relative value of the room temperature discharge resistance after the charge-discharge cycle, with the initial room temperature discharge resistance of Example 1 set to 100, was defined as the room temperature discharge DCR increase rate.

[0254] [Examples 2-54, Comparative Examples 1-18] The same procedure as in Example 1 was followed, except that the types and contents of the components used to prepare the Si-C particles 1 and the non-aqueous electrolyte were changed as shown in Tables 5 and 6. The results are shown in Tables 5 and 6. Note that the increase in charging resistance and discharge resistance after 100 charge-discharge cycles in Examples 2-18 are expressed as relative values ​​with the resistance increase in Example 1 set to 100. Similarly, the increase in charging resistance and discharge resistance after 100 charge-discharge cycles in Comparative Examples 2-18 are expressed as relative values ​​with the resistance increase in Comparative Example 1 set to 100. Furthermore, the increase in charging resistance and discharge resistance after 100 charge-discharge cycles in Examples 20-36 are expressed as relative values ​​with the resistance increase in Example 19 set to 100. Furthermore, the increase in charging resistance and discharge resistance after 100 charge-discharge cycles in Examples 38 to 54 are expressed as relative values ​​with the resistance increase in Example 37 set to 100. Note that "100 cy charge DCIR increase rate" and "100 cy discharge DCIR increase rate" in Tables 5 and 6 represent "increase in charging resistance after 100 charge-discharge cycles" and "increase in discharge resistance after 100 charge-discharge cycles," respectively. It is preferable that these increase rates be low. Furthermore, the components listed in Tables 5 and 6 are compounds represented by the following formulas.

[0255]

[0256]

[0257]

[0258] As shown in Tables 5 and 6, when comparing systems using the same non-aqueous electrolyte (for example, comparing Example 2, Example 20, Example 38, and Comparative Example 2), the non-aqueous electrolyte secondary batteries of each example, which contained Si-C particles containing silicon-containing Si domains and carbon-containing C domains as the negative electrode active material, were able to suppress the increase in resistance after charge-discharge cycles compared with the non-aqueous electrolyte secondary batteries of each comparative example, which contained SiO particles instead of the Si-C particles as the negative electrode active material (specifically, they were superior in suppressing the increase in at least one of the increase rates of charging resistance and discharge resistance after 100 charge-discharge cycle tests).

[0259] Furthermore, comparisons between Example 1 and Examples 2 to 18, between Example 19 and Examples 20 to 36, and between Example 37 and Examples 38 to 54 show that by using a non-aqueous electrolyte comprising a first component selected from the group consisting of compounds represented by formula (I) and compounds represented by formula (II), and a second component selected from the group consisting of compounds represented by formula (III-1), formula (III-2), formula (IV), formula (V), formula (VI), formula (VII), formula (VIII), formula (IX), formula (X-1), formula (X-2), formula (XI), formula (XII), and formula (XIII), the increase in resistance after the charge-discharge cycle could be further suppressed.

[0260] The disclosure of Japanese Patent Application No. 2025-067017, filed on 15 April 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

It comprises a positive electrode, a negative electrode, a non-aqueous electrolyte, and a separator. The negative electrode comprises a current collector and a negative electrode composite layer formed on the current collector and containing a negative electrode active material. The negative electrode active material comprises Si-C particles, each containing a Si domain containing a silicon component and a C domain containing a carbon component. A non-aqueous electrolyte secondary battery, wherein the non-aqueous electrolyte contains one or more compounds selected from the group consisting of the following: a compound represented by formula (I), a compound represented by formula (II), a compound represented by formula (III-1), a compound represented by formula (III-2), a compound represented by formula (IV), a compound represented by formula (V), a compound represented by formula (VI), a compound represented by formula (VII), a compound represented by formula (VIII), a compound represented by formula (IX), a compound represented by formula (X-1), a compound represented by formula (X-2), a compound represented by formula (XI), a compound represented by formula (XII), and a compound represented by formula (XIII). (In formula (I), R １１ 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 may contain at least one functional group selected from the group consisting of a fluoro group and an oxa group (-O-) as a substituent, and h represents an integer from 0 to 2. In formula (II), R ２１ 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 may contain at least one functional group selected from the group consisting of a fluoro group and an oxa group (-O-) as a substituent, where i represents an integer from 0 to 3. In equations (III-1) and (III-2), M ＋ Each of these independently represents an alkali metal ion, ammonium ion, imidazolium ion, pyridinium ion, pyrrolidinium ion, piperidinium ion, or phosphonium ion. In formula (IV), Q represents a boron atom (B) or a phosphorus atom (P), and R ４１ 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; M ＋ Each of these independently represents an alkali metal ion, ammonium ion, imidazolium ion, pyridinium ion, pyrrolidinium ion, piperidinium ion, or phosphonium ion. When Q is a boron atom (B), a represents 1 or 2, b represents 2 when a is 1, and 0 when a is 2. When Q is a phosphorus atom (P), a represents an integer from 1 to 3, b represents 4 when a is 1, 2 when a is 2, and 0 when a is 3, and c represents an integer from 1 to 3. In formula (V), R ５１ 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, M ＋ This represents alkali metal ions, alkaline earth metal ions, ammonium ions, imidazolium ions, pyridinium ions, pyrrolidinium ions, piperidinium ions, or phosphonium ions. In formula (VI), R ６１ represents a fluoro group (-F), 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, and R ６２ 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 fluoro group (-F) and an oxa group (-O-) as a substituent, or a fluorocarbon group having 1 to 12 carbon atoms which may contain an oxa group (-O-) as a substituent, and M ＋ represents an alkali metal ion, alkaline earth metal ion, ammonium ion, imidazolium ion, pyridinium ion, pyrrolidinium ion, piperidinium ion, or phosphonium ion. In formula (VII), R ７１ 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, M ＋ This represents alkali metal ions, alkaline earth metal ions, ammonium ions, imidazolium ions, pyridinium ions, pyrrolidinium ions, piperidinium ions, or phosphonium ions. In formula (VIII), R ８１ Each of these independently 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 may contain a fluoro group (-F) as a substituent, and j represents an integer from 1 to 4. In equation (IX), a double line consisting of a solid line and a dotted line represents a single bond (-) or a double bond (=), R ９１ 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 may contain at least one functional group selected from the group consisting of a fluoro group and an oxa group (-O-) as a substituent, and k represents an integer from 0 to 4. In equations (X-1) and (X-2), R １０１ and R １０２ 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 R 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 ) １０３ 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 ). In formula (XI), R １１１ This represents an m+1 valent hydrocarbon group having 1 to 24 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, where m is an integer from 0 to 4. In formula (XII), R １２１ This represents an n+1 valent hydrocarbon group having 1 to 24 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, where n is an integer from 0 to 4. In formula (XIII), R １３１ is a methylene group (-CH ２ -), ethylene group (-CH ２ CH ２ -), or n-propylene group (-CH ２ CH ２ CH ２ -) represents R １３２ Each independently represents a hydrocarbon group having 1 to 6 carbon atoms, a group represented by formula (xiiii-3), a group represented by formula (xiiii-4), a group represented by formula (xiiii-5), a group represented by formula (xiiii-6), a group represented by formula (xiiii-7), or a group represented by formula (xiiii-8), which may each contain at least one functional group selected from the group consisting of a halogen group (-X) and an oxa group (-O-) as a substituent, and p is R １３１ is a methylene group (-CH ２ When -, an integer from 0 to 2, R １３１ is an ethylene group (-CH ２ CH ２ When -, an integer from 0 to 4, R １３１ is an n-propylene group (-CH ２ CH ２ CH ２ (-) When this is the case, it represents an integer from 0 to 6. 　 The non-aqueous electrolyte comprises a first component which is one or more compounds selected from the group consisting of compounds represented by formula (I) and compounds represented by formula (II), A second component which is one or more selected from the group consisting of the compound represented by formula (III-1), the compound represented by formula (III-2), the compound represented by formula (IV), the compound represented by formula (V), the compound represented by formula (VI), the compound represented by formula (VII), the compound represented by formula (VIII), the compound represented by formula (IX), the compound represented by formula (X-1), the compound represented by formula (X-2), the compound represented by formula (XI), the compound represented by formula (XII), and the compound represented by formula (XIII), A non-aqueous electrolyte secondary battery according to claim 1, comprising: 　 The non-aqueous electrolyte secondary battery according to claim 2, wherein the total content of the first component is 0.0001% by mass to 10% by mass relative to the total amount of the non-aqueous electrolyte. 　 The non-aqueous electrolyte secondary battery according to claim 2, wherein the total content of the second component is 0.0001% by mass to 20% by mass relative to the total amount of the non-aqueous electrolyte. 　 The aforementioned Si-C particles are found at 1450 cm⁻¹ in the Raman spectrum. －１ ~1700cm －１ Maximum peak intensity I Ｇ 450 cm －１ ~600cm －１ Maximum peak intensity I Ｓｉ Ratio I Ｓｉ / I Ｇ The non-aqueous electrolyte secondary battery according to claim 1, wherein the particles are 15 or less. 　 The aforementioned Si-C particles are found at 1450 cm⁻¹ in the Raman spectrum. －１ ~1700cm －１ Maximum peak intensity I Ｇ 1200 cm －１ ~1450cm －１ Maximum peak intensity I Ｄ Ratio I Ｄ / I Ｇ However, the particles are 10 or less, as described in claim 1, for a non-aqueous electrolyte secondary battery. 　 The Si-C particles have an oxygen content m measured by X-ray fluorescence analysis (XRF). Ｏ，ＸＲＦ Silicon content m per [mass%] Ｓｉ，ＸＲＦ [Mass %] ratio m Ｓｉ，ＸＲＦ / m Ｏ，ＸＲＦ The non-aqueous electrolyte secondary battery according to claim 1, wherein the particles are 10 or more in number. 　 The Si-C particles have a silicon content measured by inductively coupled plasma atomic emission spectroscopy (ICP-AES) as mSi (total), ICP [mass%], which is silicon dioxide (SiO₂ ２ The non-aqueous electrolyte secondary battery according to claim 1, wherein the particles have a ratio of mSi(SiO2),ICP / mSi(total),ICP of silicon component content derived from ) to 0.80 or less. 　 The non-aqueous electrolyte secondary battery according to claim 1, wherein the total content of the Si-C particles is 1% by mass to 30% by mass relative to the total amount of the negative electrode active material.

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