WO2019208153A1

WO2019208153A1 - Nonaqueous electrolyte secondary battery

Info

Publication number: WO2019208153A1
Application number: PCT/JP2019/015021
Authority: WO
Inventors: 真梨恵中西; 健二撹上; 洋平青山
Original assignee: 株式会社Adeka
Priority date: 2018-04-25
Filing date: 2019-04-04
Publication date: 2019-10-31
Also published as: JPWO2019208153A1; KR20210002452A

Abstract

The present invention addresses the problem of providing a nonaqueous electrolyte secondary battery that has a high capacity even after repeated charging and discharging. The present invention is the nonaqueous electrolyte secondary battery that includes: a positive electrode that contains a sulfur-modified organic compound; a negative electrode that contains at least one metal selected from the group consisting of alkali metal and alkaline earth metal; and a nonaqueous electrolyte that contains at least one compound represented by general formula (1) and at least one metal salt selected from the group consisting of alkali metal salt and alkaline earth metal salt. (In the formula, R¹ to R³ are each independently a hydrocarbon group having 1 to 10 carbon atoms, R⁴ is an n-valent hydrocarbon group having 1 to 10 carbon atoms or an n-valent hydrocarbon group having 1 to 10 carbon atoms that includes at least one oxygen atom or sulfur atom, and n is an integer of 1 to 6.)

Description

Nonaqueous electrolyte secondary battery

The present invention relates to a non-aqueous electrolyte secondary battery including a sulfur-modified organic compound in a positive electrode and an alkali metal in a negative electrode.

Non-aqueous electrolyte secondary batteries such as lithium ion secondary batteries are small and light, have high energy density, and can be repeatedly charged and discharged, so portable electronic devices such as portable personal computers, handy video cameras, and information terminals. Widely used as a power source for equipment. From the viewpoint of environmental problems, electric vehicles using nonaqueous electrolyte secondary batteries and hybrid vehicles using electric power as a part of power have been put into practical use. Therefore, in recent years, further improvements in the performance of secondary batteries have been demanded from the viewpoints of the usable time of portable electronic devices, the cruising distance of automobiles, and the safety thereof.

Sulfur, for example, has a theoretically large electric capacity compared to a positive electrode active material such as a lithium-transition metal composite oxide, and is extremely concerned about resource reserves and costs such as transition metals. small. Further, lithium metal or an alloy containing lithium metal is lighter and has a higher energy density than a negative electrode active material for a secondary battery such as carbon intercalated with lithium ions. Therefore, a lithium-sulfur secondary battery that uses lithium metal as a negative electrode active material and a material containing sulfur as a positive electrode active material is one of the promising candidates that satisfy the above-mentioned demand.

However, in a lithium-sulfur secondary battery using sulfur as a positive electrode active material, a compound of sulfur and lithium is generated during discharge, and the active material disappears when this compound is dissolved and dispersed in the electrolyte. Therefore, the electric capacity decreases every time charging / discharging is repeated (hereinafter sometimes referred to as cycle characteristics). For this reason, sulfur-modified organic compounds having a sulfur-carbon bond have been developed and studied as positive electrode active materials (for example, Patent Documents 1 to 10). However, there is a demand for further improvement in cycle characteristics in a secondary battery using a positive electrode containing a sulfur-modified organic compound and lithium metal as a negative electrode.

On the other hand, an electrolytic solution containing a compound having a silyl ester group is a nonaqueous electrolyte secondary battery using a lithium transition metal composite oxide or a lithium-containing transition metal phosphate compound as a positive electrode active material and artificial graphite or the like as a negative electrode active material. However, it is disclosed that there is an effect of improving cycle characteristics, but a non-aqueous solution using a positive electrode using a sulfur-modified organic compound as a positive electrode active material and a negative electrode using an alkali metal such as lithium or sodium as a negative electrode active material. An electrolyte secondary battery is not known (for example, Patent Documents 11 and 12).

In addition, in a secondary battery including a lithium metal or an alloy containing lithium metal as a negative electrode active material, lithium dendrite may be formed on the negative electrode as charge and discharge are repeated, and charge / discharge cycle characteristics may be deteriorated. . For this reason, a compound added to the non-aqueous electrolyte of the secondary battery (hereinafter sometimes referred to as an electrolyte additive or electrolyte additive) reacts with the initial charge / discharge, so that a solid electrolyte interface is formed on the electrode surface. A technique for improving battery characteristics in which a film called (SEI) is formed, and dendrite formation is suppressed to suppress deterioration of cycle characteristics is disclosed. For example, Patent Document 13 discloses that SEI formed by adding hypervalent iodine to a non-aqueous electrolyte suppresses lithium dendrite growth and leads to improved cycle characteristics.

Patent Documents

14 and 15 disclose that charging-discharging efficiency and utilization efficiency of sulfur can be improved by adding LiNO ₃ to a non-aqueous electrolyte.

JP 2003-151550 A US89040436 JP 2011-028948 A JP 2011-170991 A JP 2012-099342 A JP 2012-150933 A WO2012 / 114651 US10000872 US2018072665 US2018065927 US2018026304 US2018226683 JP 2012-059541 A US7019494 US7358012

However, for example, although many electrolytic solution additives are disclosed in

Patent Documents

14 and 15, the cycle characteristics and the electric capacity after repeatedly charging and discharging a secondary battery are not sufficient. An object of the present invention is to provide a positive electrode using a sulfur-modified organic compound as a positive electrode active material, which has a high capacity even after repeated charge and discharge, and has both excellent charge / discharge characteristics at low temperatures and excellent high-temperature storage stability. Another object of the present invention is to provide a non-aqueous electrolyte secondary battery using a negative electrode using an alkali metal or alkaline earth metal such as lithium or sodium as a negative electrode active material.

As a result of intensive studies, the inventors of the present invention contain a compound having a specific structure when using a positive electrode containing a sulfur-modified organic compound and a negative electrode containing an alkali metal or alkaline earth metal including lithium metal. It has been found that the above problem can be achieved by using a non-aqueous electrolyte, and the present invention has been completed.

The present invention relates to a positive electrode containing a sulfur-modified organic compound; a negative electrode containing at least one metal selected from the group consisting of alkali metals and alkaline earth metals; and at least one compound represented by the general formula (1). And a nonaqueous electrolyte containing at least one metal salt selected from the group consisting of alkali metal salts and alkaline earth metal salts.

(Wherein R ¹ to R ³ each independently represents a hydrocarbon group having 1 to 10 carbon atoms, and R ⁴ represents an n-valent hydrocarbon group having 1 to 10 carbon atoms, or an oxygen atom or sulfur) (It represents an n-valent hydrocarbon group having 1 to 10 carbon atoms and containing at least one atom, and n represents an integer of 1 to 6.)

FIG. 1 is a longitudinal sectional view schematically showing an example of the structure of a coin-type battery of the nonaqueous electrolyte secondary battery of the present invention. FIG. 2 is a schematic view showing a basic configuration of a cylindrical battery of the nonaqueous electrolyte secondary battery of the present invention. FIG. 3 is a perspective view showing the internal structure of the cylindrical battery of the nonaqueous electrolyte secondary battery of the present invention as a cross section.

Hereinafter, the nonaqueous electrolyte secondary battery of the present invention will be described in detail based on preferred embodiments.

<Positive electrode>
The positive electrode used for the nonaqueous electrolyte secondary battery of the present invention contains a sulfur-modified organic compound. In the present invention, the sulfur-modified organic compound acts as a positive electrode active material. The sulfur content of the sulfur-modified organic compound is not particularly limited, but is preferably 25% by mass or more, and more preferably 30% by mass or more.

The sulfur-modified organic compound used in the present invention is obtained by heat-treating an organic compound and sulfur. Examples of the compound obtained by heat treating an organic compound and sulfur include, for example, a sulfur-modified polyacrylonitrile compound, a sulfur-modified elastomer compound, a sulfur-modified pitch compound, a sulfur-modified polynuclear aromatic ring compound, a sulfur-modified aliphatic hydrocarbon oxide, and a sulfur-modified polyether. Examples thereof include compounds, polythienoacene compounds, sulfur-modified polyamide compounds, and polysulfide carbon. These compounds are a mixture of sulfur and polyacrylonitrile compound, elastomer compound, pitch compound, polynuclear aromatic ring compound, aliphatic hydrocarbon oxide, polyether compound, polyacene compound, polyamide compound, or hexachlorobutadiene, It can be produced by heat-denaturing at 250 to 600 ° C. in a non-oxidizing atmosphere. When these compounds are heated with sulfur, only one of these compounds may be used, or two or more may be used in combination. The sulfur-modified organic compound is preferably a sulfur-modified polyacrylonitrile compound because a large charge / discharge capacity can be obtained.

Non-oxidizing atmosphere means an oxygen concentration of less than 5% by volume, preferably less than 2% by volume, more preferably an atmosphere substantially free of oxygen, for example, an inert gas atmosphere such as nitrogen, helium, argon, It is a sulfur gas atmosphere.

The sulfur-modified polyacrylonitrile compound is a compound obtained by heat-treating a polyacrylonitrile compound and elemental sulfur in a non-oxidizing atmosphere. The polyacrylonitrile compound may be a homopolymer of acrylonitrile or a copolymer of acrylonitrile and other monomers. When the content of acrylonitrile in the polyacrylonitrile compound decreases, the battery performance decreases, and further, carbonization is relatively easy and the carbide exhibits a relatively high conductivity. Therefore, the utilization ratio of the active material is improved and the capacity is increased. In view of the possibility, the content of acrylonitrile in the copolymer of acrylonitrile and other monomers is preferably at least 90% by mass, and more preferably a polyacrylonitrile homopolymer. Examples of other monomers include acrylic acid, vinyl acetate, N-vinylformamide, and N, N′-methylenebis (acrylamide). The temperature of the heat treatment is preferably 250 ° C. to 550 ° C., and the sulfur content of the sulfur-modified polyacrylonitrile is preferably 30 to 60% by mass because a large charge / discharge capacity can be obtained.

The sulfur-modified elastomer compound is a compound obtained by heat-treating a mixture of rubber and elemental sulfur in a non-oxidizing atmosphere. Examples of the rubber include natural rubber, isoprene rubber, butadiene rubber, styrene butadiene rubber, and acrylonitrile butadiene rubber. These rubber | gum can be used individually by 1 type, and can be used in combination of 2 or more type. The raw rubber may be vulcanized rubber or unvulcanized rubber. The temperature of the heat treatment is preferably 250 ° C. to 550 ° C., and the sulfur content of the sulfur-modified elastomer compound is preferably 40 to 70% by mass because a large charge / discharge capacity can be obtained.

The sulfur-modified pitch compound is a compound obtained by heat-treating a mixture of pitches and elemental sulfur in a non-oxidizing atmosphere. Pitches include petroleum pitch, coal pitch, mesophase pitch, asphalt, coal tar, coal tar pitch, organic synthetic pitch obtained by polycondensation of condensed polycyclic aromatic hydrocarbon compounds, and heteroatom-containing condensed polycyclic aroma. And organic synthetic pitch obtained by polycondensation of a group hydrocarbon compound. Pitches are a mixture of various compounds and contain fused polycyclic aromatics. The condensed polycyclic aromatic contained in the pitches may be a single species or a plurality of species. This condensed polycyclic aromatic may contain nitrogen or sulfur in addition to carbon and hydrogen in the ring. The temperature of the heat treatment is preferably 300 ° C. to 500 ° C., and the sulfur content of the sulfur-modified pitch compound is preferably 25 to 70% by mass because a large charge / discharge capacity can be obtained.

Sulfur-modified polynuclear aromatic ring compounds include, for example, a mixture of benzene-based aromatic ring compounds such as naphthalene, anthracene, tetracene, pentacene, phenanthrene, chrysene, picene, pyrene, benzopyrene, perylene, coronene, and simple sulfur in a non-oxidizing atmosphere. It is a compound obtained by heat-treating. In addition, aromatic ring compounds in which part of the benzene aromatic ring compound is a 5-membered ring, or hetero atom-containing heteroaromatic ring compounds in which some of these carbon atoms are replaced with sulfur, oxygen, nitrogen, etc. . Further, these polynuclear aromatic ring compounds are linear or branched alkyl groups having 1 to 12 carbon atoms, alkoxyl groups, hydroxyl groups, carboxyl groups, amino groups, aminocarbonyl groups, aminothio groups, mercaptothiocarbonylamino groups, carboxy groups. It may have a substituent such as an alkylcarbonyl group. The temperature of the heat treatment is preferably 250 ° C. to 550 ° C., and the sulfur content of the sulfur-modified pitch compound is preferably 40 to 70% by mass because a large charge / discharge capacity can be obtained.

Sulfur-modified aliphatic hydrocarbon oxides are obtained by heat-treating aliphatic hydrocarbon oxides such as aliphatic alcohols, aliphatic aldehydes, aliphatic ketones, aliphatic epoxides, and fatty acids and simple sulfur in a non-oxidizing atmosphere. The resulting compound. The temperature of the heat treatment is preferably 300 ° C to 500 ° C. The sulfur content of the sulfur-modified aliphatic hydrocarbon oxide is preferably 45 to 75% by mass because a large charge / discharge capacity can be obtained.

The sulfur-modified polyether compound is a compound obtained by heat-treating a polyether compound and elemental sulfur in a non-oxidizing atmosphere. Examples of the polyether compound include polyethylene glycol, polypropylene glycol, ethylene oxide / propylene oxide copolymer, polytetramethylene glycol, and the like. The polyether compound may be terminated with an alkyl ether group, an alkylphenyl ether group or an acyl group, or may be an ethylene oxide adduct of a polyol such as glycerin or sorbitol. The temperature of the heat treatment is preferably 250 to 500 ° C. The sulfur content of the sulfur-modified polyether compound is preferably 30 to 75% by mass because a large charge / discharge capacity can be obtained.

The polythienoacene compound is a compound having a polythienoacene structure containing sulfur represented by the following general formula (3). The polythienoacene compound is a compound obtained by heat-treating an aliphatic polymer compound having a linear structure such as a polyethylene compound or a polymer compound having a thiophene structure such as polythiophene and simple sulfur in a non-oxidizing atmosphere. The temperature of the heat treatment is preferably 300 ° C. to 600 ° C. The sulfur content of the polythienoacene compound is preferably 30 to 80% by mass because a large charge / discharge capacity can be obtained.

(In the formula, * represents a bond.)

The sulfur-modified polyamide compound is a sulfur-modified organic compound having a carbon skeleton derived from a polymer having an amide bond, specifically, an aminocarboxylic acid compound and simple sulfur, or a polyamine compound and polycarboxylic acid compound and simple sulfur, It is a compound obtained by heat treatment in a non-oxidizing atmosphere. The temperature of the heat treatment is preferably 250 to 600 ° C. The sulfur content of the sulfur-modified polyamide compound is preferably 40 to 70% by mass because a large charge / discharge capacity can be obtained.

The polysulfide carbon is a compound represented by the general formula (CS _x ) _n (x is 0.5 to 2, n is a number of 4 or more), for example, alkali metal sulfide such as sodium sulfide. It can be obtained by heat-treating a precursor in which a halogenated unsaturated hydrocarbon such as hexachlorobutadiene is reacted with a complex of a product and elemental sulfur. The temperature of the heat treatment is preferably 300 to 450 ° C., and the sulfur content of the polysulfide carbon compound is preferably 65 to 75% by mass because a large charge / discharge capacity can be obtained.

The sulfur content can be measured by performing elemental analysis using, for example, a CHN analyzer (such as Elementer Vario MICRO cube) that can analyze sulfur and oxygen.

In addition to the above materials during heating, graphite carbon materials such as natural graphite, artificial graphite and expanded graphite, carbon materials such as carbon black, activated carbon, carbon fiber, coke, soft carbon, hard carbon, carbon nanotubes, tetramethylthiuram Vulcanization accelerators such as disulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide, tetrakis (2-ethylhexyl) thiuram disulfide, tetramethylthiuram monosulfide, dipentamethylenethiuram tetrasulfide can be used. These can be used alone or in combination of two or more. The carbon material and the vulcanization accelerator can be blended in a known blending recipe at a known blending ratio.

The shape of the sulfur-modified organic compound is not particularly limited. For example, it is spherical, polyhedral, fibrous, rod-like, plate-like, scale-like, or amorphous, and these may be hollow. Among these, since the electrode mixture layer is uniformly formed, a spherical or polyhedral shape is preferable.

If the particle size of the sulfur-modified organic compound is small, it becomes difficult to handle the powder. On the other hand, if the particle size is large, the uniformity / smoothness of the electrode decreases, so the sulfur-porous carbon composite, or The average particle diameter (D50) of the sulfur-modified organic compound is preferably 0.5 to 100 μm, more preferably 1 μm to 50 μm, and still more preferably 1 μm to 20 μm. In the present invention, the average particle diameter (D50) refers to a 50% particle diameter measured by a laser diffraction light scattering method. The particle diameter is a volume-based diameter, and the diameter of secondary particles is measured by the laser diffraction light scattering method.

The sulfur-modified organic compound can have a desired particle size by a method such as pulverization. The pulverization may be dry pulverization performed in a gas or wet pulverization performed in a liquid such as water. Examples of the industrial pulverization method include a ball mill, a roller mill, a turbo mill, a jet mill, a cyclone mill, a hammer mill, a pin mill, a rotating mill, a vibration mill, a planetary mill, an attritor, and a bead mill.

The positive electrode used in the present invention can be produced according to a known method. For example, the electrode mixture is applied onto the current collector by applying a mixture of the positive electrode active material, the binder and the conductive additive to the current collector by applying an electrode mixture paste slurryed with an organic solvent or water to the current collector. A positive electrode on which a layer is formed can be produced.

<Binder>
Known binders can be used as the binder used in the present invention. Specific examples of the binder include, for example, styrene-butadiene rubber, butadiene rubber, acrylonitrile-butadiene rubber, ethylene-propylene-diene rubber, styrene-isoprene rubber, fluorine rubber, polyethylene, polypropylene, polyamide, polyamideimide, polyimide, polyacrylonitrile, Polyurethane, polyvinylidene fluoride, polytetrafluoroethylene, styrene-acrylic acid ester copolymer, ethylene-vinyl alcohol copolymer, polymethyl methacrylate, polyacrylate, polyvinyl alcohol, polyethylene oxide, polyvinyl pyrrolidone, polyvinyl ether, polyvinyl chloride , Polyacrylic acid, methylcellulose, carboxymethylcellulose, sodium carboxymethylcellulose, Loin nanofibers, and starch.
As the binder, an aqueous binder is preferable because it has a low environmental load and sulfur elution hardly occurs. Styrene-butadiene rubber, sodium carboxymethyl cellulose, and polyacrylic acid are more preferable.
Only one binder can be used, or two or more binders can be used in combination.
The content of the binder is preferably 1 to 30 parts by mass, more preferably 1 to 20 parts by mass with respect to 100 parts by mass of the positive electrode active material.

<Conductive aid>
As the conductive assistant used in the present invention, those known as conductive assistants for electrodes can be used. Specifically, for example, natural graphite, artificial graphite, coal tar pitch, carbon black, acetylene black, ketjen black, channel black, furnace black, lamp black, thermal black, carbon nanotube, vapor grown carbon fiber (Vapor Grown) Carbon Fiber (VGCF), graphene, fullerene, needle coke and other carbon materials; metal powders such as aluminum powder, nickel powder and titanium powder; conductive metal oxides such as zinc oxide and titanium oxide; La ₂ S ₃ and Sm ₂ Examples thereof include sulfides such as S ₃ , Ce ₂ S ₃ and TiS ₂ . This conductive auxiliary agent can be mixed during the production of the sulfur-modified organic compound.
The particle size of the conductive aid is preferably 0.0001 μm to 100 μm, and more preferably 0.01 μm to 50 μm.
The content of the conductive assistant is usually 0.1 to 50 parts by mass, preferably 1 to 30 parts by mass, more preferably 2 to 20 parts by mass with respect to 100 parts by mass of the electrode active material.

<Solvent>
Solvents for preparing the electrode mixture paste include, for example, propylene carbonate, ethylene carbonate, diethyl carbonate, dimethyl carbonate, ethyl methyl carbonate, 1,2-dimethoxyethane, 1,2-diethoxyethane, acetonitrile, propio Nitrile, tetrahydrofuran, 2-methyltetrahydrofuran, dioxane, 1,3-dioxolane, nitromethane, N-methylpyrrolidone, N, N-dimethylformamide, dimethylacetamide, methyl ethyl ketone, cyclohexanone, methyl acetate, methyl acrylate, diethyltriamine, N, N-dimethylaminopropylamine, polyethylene oxide, tetrahydrofuran, dimethyl sulfoxide, sulfolane, γ-butyrolactone, water, alcohol And the like. The amount of the solvent used can be adjusted according to the method selected when coating the slurry. For example, in the case of application by the doctor blade method, the total amount of the sulfur-modified organic compound, the binder and the conductive auxiliary agent is 100 mass. The amount is preferably 20 to 300 parts by mass, more preferably 30 to 200 parts by mass with respect to parts.

The electrode mixture paste composition contains, in addition to the above components, other components such as, for example, a viscosity modifier, a reinforcing material, an antioxidant, a pH adjuster, and a dispersant, as long as the effects of the present invention are not impaired. It does n’t matter. As these other components, known components can be used at a known blending ratio.

<Electrode mixture paste manufacturing process>
In the production of the electrode mixture paste, when the positive electrode active material, the binder and the conductive additive are dispersed or dissolved in the solvent, all of them can be added to the solvent at once and dispersed, or separately added and dispersed. You can also. It is preferable to sequentially add a binder, a conductive additive, and an active material in the solvent in the order of the dispersion treatment, since these can be uniformly dispersed in the solvent. When the electrode mixture paste contains other components, the other components can be added all at once, and the dispersion treatment can be performed. However, the dispersion treatment is preferably performed every time one kind is added.

The dispersion treatment method is not particularly limited, but as an industrial method, for example, a normal ball mill, sand mill, bead mill, cyclone mill, pigment disperser, crushed grinder, ultrasonic disperser, homogenizer, rotation / revolution mixer, Planetary mixers, fill mixes, jet pasters, etc. can be used.

<Current collector>
As the current collector, a conductive material such as titanium, titanium alloy, aluminum, aluminum alloy, nickel, stainless steel, nickel-plated steel, or the like is used. Examples of the shape of the current collector include a foil shape, a plate shape, and a net shape, and the current collector may be either porous or non-porous. In addition, these conductive materials may be subjected to surface treatment in order to improve adhesion and electrical characteristics. Among these conductive materials, aluminum is preferable from the viewpoint of conductivity and price, and aluminum foil is particularly preferable. The thickness of the current collector is not particularly limited, but is usually 5 to 30 μm.

<Positive electrode manufacturing process>
The method for applying the electrode mixture paste composition to the current collector is not particularly limited. For example, the die coater method, comma coater method, curtain coater method, spray coater method, gravure coater method, flexo coater method, knife coater method Each method such as a doctor blade method, a reverse roll method, a brush coating method, and a dip method can be used. A die coater method, a knife coater method, and a doctor blade method are preferable in that a favorable surface state of the coating layer can be obtained in accordance with the viscosity and drying property of the electrode mixture paste.

Application | coating to the electrical power collector of an electrode mixture paste composition can be performed to the single side | surface of a collector, and can also be performed to both surfaces. In the case of applying to both sides of the current collector, each side can be applied sequentially, or both sides can be applied simultaneously. Moreover, it can apply | coat continuously on the surface of an electrical power collector, can also apply | coat intermittently, and can also apply | coat in stripe form. The thickness, length and width of the coating layer can be appropriately determined according to the size of the battery and the like.

The method for drying the electrode mixture paste composition applied on the current collector is not particularly limited, and a known method can be used. Examples of the drying method include drying with warm air, hot air, low-humidity air, vacuum drying, drying by irradiation with far infrared rays, infrared rays, electron beams, or the like. These can be implemented in combination. The temperature at the time of heating is, for example, generally about 50 ° C. to 180 ° C., but the conditions such as the temperature can be appropriately set according to the coating amount of the slurry composition, the boiling point of the solvent used, and the like. . By this drying, volatile components such as a solvent are volatilized from the coating film of the electrode mixture paste composition, and an electrode mixture layer is formed on the current collector.

<Negative electrode>
The negative electrode used for the nonaqueous electrolyte secondary battery of the present invention contains at least one metal selected from the group consisting of alkali metals and alkaline earth metals. In the present invention, these metals act as a negative electrode active material.

Examples of the alkali metal include lithium, sodium, and potassium. These alloys can also be used as the negative electrode active material.
Examples of the alloy containing an alkali metal include a lithium alloy and a sodium alloy. The lithium alloy is not particularly limited as long as the effect of the present invention is not hindered. For example, one or more metals selected from the group consisting of lithium and aluminum, lead, bismuth, indium, gallium, nickel, germanium, silicon, and tin. And alloys thereof. Furthermore, what added the other metal 1 mass% or less to these lithium alloys can also be used. Among these lithium alloys, those containing 30% by mass or more of lithium are preferable, and those containing 40% by mass or more are more preferable. Although it does not specifically limit as long as the effect of this invention is not prevented as a sodium alloy, For example, the alloy of sodium and 1 or more types of metals chosen from the group of aluminum, silicon, tin, magnesium, indium, calcium is mentioned. . Furthermore, what added 1 mass% of other metals to these sodium alloys can also be used. Among these sodium alloys, those containing 30% by mass or more of sodium are preferable, and those containing 50% by mass or more are more preferable.

Examples of the alkaline earth metal include magnesium, calcium, strontium, barium and the like. These alloys can also be used as the negative electrode active material.
Examples of the alloy containing an alkaline earth metal include a magnesium alloy and a calcium alloy. Further, these magnesium alloys are not limited as long as the effects of the present invention are not hindered. For example, an alloy with one or more metals selected from the group of silver, indium, aluminum, nickel, germanium, silicon, and tin is used. Can be mentioned. Furthermore, what added 1 mass% or less of other metals to these magnesium alloys can also be used. Among these magnesium metals, those containing 30% by mass or more of magnesium are preferable, and those containing 40% by mass or more are more preferable. The calcium alloy is not limited as long as the effects of the present invention are not hindered. Examples of the calcium alloy include alloys with one or more metals selected from the group consisting of silver, indium, aluminum, nickel, germanium, silicon, and tin. Furthermore, what added 1 mass% or less of other metals to these calcium alloys can also be used. Among these calcium metals, those containing 30% by mass or more of calcium are preferable, and those containing 40% by mass or more are more preferable.

An alkali metal, alkaline earth metal, or an alloy containing an alkali metal or alkaline earth metal may have an inorganic protective layer or an organic protective layer on the surface, and a laminate of these may also be used. .
Among the alkali metals, alkaline earth metals, and alloys containing alkali metals or alkaline earth metals, lithium and sodium are preferable, and lithium is more preferable.
The shape of the alkali metal, the alkaline earth metal, and the alloy containing the alkali metal or the alkaline earth metal is not particularly limited, but may be, for example, a foil shape, a plate shape, a sheet shape, or a mesh shape. Among these, a plate shape and a foil shape are preferable from the viewpoint of ease of handling. The thickness is not particularly limited, but is generally 10 μm to 3 mm, preferably 50 μm to 1 mm.

The negative electrode current collector may not be used because the negative electrode active material itself has high electronic conductivity. However, depending on the configuration of the battery, a metal material that does not form an alloy with the negative electrode active material is used as the negative electrode current collector. You can also Although it does not specifically limit as a metal material, Stainless steel, copper, nickel, or silver is mentioned. After forming the negative electrode active material to a required size, the negative electrode can be manufactured by pressure bonding on the current collector, and after forming the negative electrode active material on the current collector, the required size is formed. You can also

<Nonaqueous electrolyte>
The nonaqueous electrolyte used in the nonaqueous electrolyte secondary battery of the present invention is at least one compound selected from the group consisting of at least one compound represented by the following general formula (1) and an alkali metal salt and an alkaline earth metal salt. Contains one metal salt. By using a nonaqueous electrolyte containing at least one compound represented by the following general formula (1), a nonaqueous electrolyte secondary battery having a high capacity can be obtained even after repeated charge and discharge.

Examples of the hydrocarbon group having 1 to 10 carbon atoms include methyl group, ethyl group, propyl group, i-propyl group, butyl group, 2-butyl group, i-butyl group, t-butyl group, pentyl group, aliphatic saturated hydrocarbon groups such as i-pentyl, n-hexyl, n-heptyl, n-octyl, 2-ethylhexyl, nonyl, decyl; vinyl, allyl, butenyl, pentenyl Aliphatic unsaturated hydrocarbon groups such as hexenyl group and octenyl group; alicyclic hydrocarbon groups such as cyclopentyl group, cyclohexyl group and methylcyclohexyl group; phenyl group, methylphenyl group, ethylphenyl group, t-butylphenyl group And aromatic hydrocarbon groups such as phenylmethyl group, phenylethyl group, naphthyl group, thienyl group, and benzothienyl group. The hydrocarbon group having 1 to 10 carbon atoms is preferably a methyl group, an ethyl group, a butyl group, a vinyl group, or a phenyl group because excellent cycle characteristics and a high capacity can be obtained even after repeated charge and discharge use. A methyl group is more preferred.

R ^{4 in the} general formula (1) represents an n-valent hydrocarbon group having 1 to 10 carbon atoms or an n-valent hydrocarbon group having 1 to 10 carbon atoms containing at least one oxygen atom or sulfur atom. , N represents an integer of 1-6.
Among the compounds represented by the general formula (1), a compound in which R ⁴ is an n-valent hydrocarbon group having 1 to 10 carbon atoms is represented by n hydrogen atoms of a hydrocarbon having 1 to 10 carbon atoms. Can be paraphrased as a compound substituted with a group represented by the following general formula (1a).

(Wherein R ¹ to R ³ have the same meanings as in general formula (1), and * represents a binding site.)

Examples of the hydrocarbon having 1 to 10 carbon atoms include saturated hydrocarbons having 1 to 10 carbon atoms, unsaturated hydrocarbons having 2 to 10 carbon atoms, and aromatic hydrocarbons having 6 to 10 carbon atoms. The saturated hydrocarbon having 1 to 10 carbon atoms and the unsaturated hydrocarbon having 2 to 10 carbon atoms may have a straight chain structure or a branched structure.

Examples of the saturated hydrocarbon having 1 to 10 carbon atoms include methane, ethane, n-propane, n-butane, n-pentane, n-hexane, cyclohexane, heptane, octane, nonane, decane, adamantane and the like. .
Examples of unsaturated hydrocarbons having 2 to 10 carbon atoms include ethene, ethyne, propene, propyne, 1-butene, 2-butene, 1,3-butadiene, 1-pentene, 2-pentene, 1,3- Pentadiene, 1-hexene, 3-hexene, 1,3,5-hexatriene, cyclohexene, 1-heptene, 1-octene, 3-octene, 1,3,5,7-octatetraene, 1-nonene, 1 -Decene and the like.
Examples of the aromatic hydrocarbon having 6 to 10 carbon atoms include benzene, phenol, methylbenzene, dimethylbenzene, ethylbenzene, butylbenzene, naphthalene, and the like.

As a compound in which two hydrogen atoms of a saturated hydrocarbon having 1 to 10 carbon atoms are substituted with a group represented by the general formula (1a), the following compound No. 1-1-No. 1-13. In addition, Compound No. A compound such as 1-12 indicates that the substitution position is an arbitrary position.

2 hydrogen atoms of an unsaturated hydrocarbon having 2 to 10 carbon atoms or 3 to 4 hydrogen atoms of a saturated hydrocarbon having 1 to 10 carbon atoms is a group represented by the general formula (1a) As a substituted compound, Compound No. 2-1. 2-23. The compound containing a double bond may be E-form or Z-form. Among these, since the excellent cycle characteristics and high capacity can be obtained even after repeated charge / discharge use, the compound No. 2-1, compound no. 2-6, Compound No. 2 2-7 are preferred, and compound no. 2-1 is more preferable.

As a compound in which two hydrogen atoms of an aromatic hydrocarbon having 6 to 10 carbon atoms are substituted with a group represented by the general formula (1a), the following compound No. 3-1. 3-7.

As the hydrocarbon having 1 to 10 carbon atoms, methane, ethane, ethene and benzene are preferable, and ethene and benzene are more preferable because of excellent cycle characteristics and high capacity after repeated charge and discharge use. Further, n is preferably 2 to 4 and more preferably 2 because excellent cycle characteristics, high capacity can be obtained even after repeated charge and discharge use, and synthesis is easy.

When R ^{4 of the} compound represented by the general formula (1) is an n-valent hydrocarbon having 1 to 10 carbon atoms and containing at least one oxygen atom or sulfur atom, R ⁴ is an oxygen atom or sulfur. An n-valent aliphatic hydrocarbon having 1 to 10 carbon atoms containing at least one atom or an n-valent heterocyclic compound having 2 to 10 carbon atoms.

Among the compounds represented by the general formula (1), R ⁴ is a divalent to tetravalent aliphatic hydrocarbon having 1 to 10 carbon atoms containing at least one oxygen atom or sulfur atom. The following compound No. 4-1. 4-18. Among these, since the excellent cycle characteristics and high capacity can be obtained even after repeated charge / discharge use, the compound No. 4-1, compound no. 4-7, and compound no. 4-10 is preferred, and compound No. 4-1 and compound no. 4-7 is more preferable.

Among the compounds represented by the general formula (1), when R ⁴ is a heterocyclic compound having 2 to 10 carbon atoms containing at least one oxygen atom or sulfur atom, examples of the heterocyclic compound include: Oxolane, thiolane, furan, thiophene, oxane, thiane, pyran, benzofuran, benzothiophene, thienothiophene, dibenzofuran, dibenzothiophene and the like. Among these, thiophene and furan are preferable, and thiophene is more preferable because excellent cycle characteristics and high capacity can be obtained even after repeated charge and discharge use. Of the compounds represented by the general formula (1), R ⁴ is a heterocyclic compound having 2 to 10 carbon atoms, and n is 2, for example, the following compound No. 5-1 to No. 5 5-14.

The above compound No. exemplified as the compound represented by the general formula (1). 1-1-No. 5-14, it is possible to produce a non-aqueous electrolyte secondary battery having a high capacity even after repeated charge and discharge, having both excellent charge / discharge characteristics at low temperatures and excellent high-temperature storage stability. No. 2-1, 2-6, 2-7, 3-1, 4-1, 4-2, 4-7, 4-10, 4-12, 5-3, 5-4 are preferred. 2-1, 4-7, and 5-4 are more preferable.

The nonaqueous electrolyte used in the present invention contains at least one compound represented by the general formula (1). By containing the compound, a nonaqueous electrolyte secondary battery having a high electric capacity can be obtained even after repeated charge and discharge.
The content of the compound is preferably 0.01% by mass to 20% by mass in the nonaqueous electrolyte, more preferably 0.05% by mass to 10% by mass in the nonaqueous electrolyte, Most preferably, it is 0.1% by mass to 5% by mass in the electrolyte. When the content of the compound is too small, the effect of improving the electric capacity after the cycle is not sufficient, and when it is too large, an effect commensurate with the blending amount is not seen, and instead of the non-aqueous electrolyte secondary battery. May adversely affect properties.

The non-aqueous electrolyte used in the present invention does not include a non-aqueous electrolyte obtained by dissolving a metal salt in an organic solvent, a polymer gel electrolyte in which the metal salt is dissolved in an organic solvent and gelled with a polymer, and does not contain an organic solvent. Any genuine polymer electrolyte in which a metal salt is dispersed in a polymer can be used.

<Metal salt>
When the negative electrode of the non-aqueous electrolyte secondary battery of the present invention is lithium or a lithium metal alloy, the metal salt used for the non-aqueous electrolyte and the polymer gel electrolyte may be a conventionally known lithium salt such as LiPF ₆ , LiBF ₄ , LiAsF ₆ , LiCF ₃ SO ₃ , LiCF ₃ CO ₂ , LiN (CF ₃ SO ₂ ) ₂ , LiN (C ₂ F ₅ SO ₂ ) ₂ , LiN (SO ₂ F) ₂ , LiC (CF ₃ SO ₂ ) ₃ , LiB (CF ₃ SO ₃ ) ₄ , LiB (C ₂ O ₄ ) ₂ , LiBF ₂ (C ₂ O ₄ ), LiSbF ₆ , LiSiF ₅ , LiSCN, LiClO ₄ , LiCl, LiF, LiBr, LiI, LiAlF ₄ , LiAlCl ₄ , LiPO ₂ F ₂ , and derivatives thereof, among which LiPF ₆ , LiBF ₄ LiClO ₄ , LiAsF ₆ , LiCF ₃ SO ₃ , LiN (CF ₃ SO ₂ ) ₂ , LiN (C ₂ F ₅ SO ₂ ) ₂ , LiN (SO ₂ F) ₂ , LiC (CF ₃ SO ₂ ) ₃ , LiCF _It is preferable to use one or more selected from the group consisting of derivatives of ₃ SO ₃ and derivatives of LiC (CF ₃ SO ₂ ) ₃ .

Examples of the metal salt used for the pure polymer electrolyte when the non-aqueous electrolyte secondary battery of the present invention is a lithium ion secondary battery include LiN (CF ₃ SO ₂ ) ₂ and LiN (C ₂ F ₅ SO _2). ) ₂ , LiN (SO ₂ F) ₂ , LiC (CF ₃ SO ₂ ) ₃ , LiB (CF ₃ SO ₃ ) ₄ , and LiB (C ₂ O ₄ ) ₂ .

The lithium salt concentration in the non-aqueous electrolyte of a lithium ion secondary battery may be insufficient if the lithium salt concentration is too low. If the lithium salt concentration is too high, the stability of the non-aqueous electrolyte may be reduced. Since there is a risk of damage, 0.5 to 7 mol / L is preferable, and 0.8 to 1.8 mol / L is more preferable. The lithium salt can be used in combination of two or more.

When the negative electrode of the non-aqueous electrolyte secondary battery of the present invention is sodium or a sodium metal alloy, the metal salt used for the non-aqueous electrolyte and the polymer gel electrolyte is sodium obtained by replacing lithium in the lithium salt with sodium. A salt can be used, and the sodium salt can be used at the same concentration as the lithium salt in the case of a lithium ion secondary battery. Sodium salts can be used in combination of two or more.

The non-aqueous electrolyte of the present invention can further contain nitrate and nitrite in addition to the metal salt. Examples of nitrates include lithium nitrate, sodium nitrate, potassium nitrate, cesium nitrate, barium nitrate, ammonium nitrate, manganese nitrate, zinc nitrate, and nickel nitrate. Examples of the nitrite include lithium nitrite, sodium nitrite, potassium nitrite, cesium nitrite, ammonium nitrite, manganese nitrite, zinc nitrite, and nickel nitrite.
Among nitrates and nitrites, lithium nitrate and sodium nitrate are preferable because a high capacity can be obtained after the charge / discharge cycle. The concentration of nitrate and nitrite in the non-aqueous electrolyte is preferably 0.01% by mass to 10% by mass, and preferably 0.1% by mass to 5% by mass because a high capacity is obtained after the charge / discharge cycle. % Is more preferable.

As the organic solvent used in the non-aqueous electrolyte of the present invention, an organic solvent usually used for a non-aqueous electrolyte of a non-aqueous electrolyte secondary battery can be used. Examples of organic solvents that are usually used in nonaqueous electrolytes of nonaqueous electrolyte secondary batteries include saturated cyclic carbonate compounds, saturated cyclic ester compounds, sulfoxide compounds, sulfone compounds, amide compounds, saturated chain carbonate compounds, and chain ethers. Examples thereof include a compound, a cyclic ether compound, and a saturated chain ester compound. The organic solvent can be used alone or in combination of two or more.

Of the organic solvents, saturated cyclic carbonate compounds, saturated cyclic ester compounds, sulfoxide compounds, sulfone compounds, and amide compounds are preferable because they have a high relative dielectric constant and thus serve to increase the dielectric constant of the nonaqueous electrolyte. A saturated cyclic carbonate compound is particularly preferable.
Examples of the saturated cyclic carbonate compound include ethylene carbonate, 1,2-propylene carbonate, 1,3-propylene carbonate, 1,2-butylene carbonate, 1,3-butylene carbonate, 1,1-dimethylethylene carbonate, and the like. It is done. Examples of the saturated cyclic ester compound include γ-butyrolactone, γ-valerolactone, γ-caprolactone, δ-hexanolactone, and δ-octanolactone. Examples of the sulfoxide compound include dimethyl sulfoxide, diethyl sulfoxide, dipropyl sulfoxide, diphenyl sulfoxide, thiophene, and the like. Examples of the sulfone compound include dimethyl sulfone, diethyl sulfone, dipropyl sulfone, diphenyl sulfone, sulfolane (also referred to as tetramethylene sulfone), 3-methyl sulfolane, 3,4-dimethyl sulfolane, 3,4-diphenmethyl sulfolane. , Sulfolane, 3-methylsulfolene, 3-ethylsulfolene, 3-bromomethylsulfolene and the like, and sulfolane and tetramethylsulfolane are preferable. Examples of the amide compound include N-methylpyrrolidone, dimethylformamide, dimethylacetamide and the like.

Among the organic solvents, saturated chain carbonate compounds, chain ether compounds, cyclic ether compounds and saturated chain ester compounds can reduce the viscosity of the nonaqueous electrolyte and increase the mobility of electrolyte ions. Battery characteristics such as output density can be made excellent. Moreover, since it is low-viscosity, the performance of the nonaqueous electrolyte at low temperatures can be enhanced. In particular, a saturated chain carbonate compound is preferable. Examples of the saturated chain carbonate compound include dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, ethyl butyl carbonate, methyl-t-butyl carbonate, diisopropyl carbonate, t-butyl propyl carbonate, and the like. Examples of the chain ether compound or the cyclic ether compound include dimethoxyethane, ethoxymethoxyethane, diethoxyethane, tetrahydrofuran, dioxolane, dioxane, 1,2-bis (methoxycarbonyloxy) ethane, 1,2-bis ( Ethoxycarbonyloxy) ethane, 1,2-bis (ethoxycarbonyloxy) propane, ethylene glycol bis (trifluoroethyl) ether, propylene glycol bis (trifluoroethyl) ether, ethylene glycol bis (trifluoromethyl) ether, diethylene glycol bis (Trifluoroethyl) ether and the like can be mentioned, and among these, dioxolane is preferable.

As the saturated chain ester compound, monoester compounds and diester compounds having a total number of carbon atoms in the molecule of 2 to 8 are preferable, and specific compounds include, for example, methyl formate, ethyl formate, methyl acetate, Ethyl acetate, propyl acetate, isobutyl acetate, butyl acetate, methyl propionate, ethyl propionate, methyl butyrate, methyl isobutyrate, methyl trimethyl acetate, ethyl trimethyl acetate, methyl malonate, ethyl malonate, methyl succinate, ethyl succinate , Methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethylene glycol diacetyl, propylene glycol diacetyl, etc., including methyl formate, ethyl formate, methyl acetate, ethyl acetate, propyl acetate, isobutyl acetate, butyl acetate, propionic acid Me Le, and ethyl propionate are preferred.

In addition, for example, acetonitrile, propionitrile, nitromethane, derivatives thereof, and various ionic liquids can be used as the organic solvent used for the preparation of the nonaqueous electrolytic solution.

Examples of the polymer used for the polymer gel electrolyte include polyethylene oxide, polypropylene oxide, polyvinyl chloride, polyacrylonitrile, polymethyl methacrylate, polyethylene, polyvinylidene fluoride, and polyhexafluoropropylene. Examples of the polymer used in the pure polymer electrolyte include polyethylene oxide, polypropylene oxide, and polystyrene sulfonic acid.
There is no restriction | limiting in particular about the compounding ratio in a gel electrolyte, and the compounding method, A compounding ratio well-known in this technical field and a well-known compounding method are employable.

The nonaqueous electrolyte used in the present invention may contain an azide, an organic nitro compound, a pyridine N-oxide compound, an alkylamine N-oxide compound or tetramethylpiperidine N-oxyl in order to increase the capacity after a charge / discharge cycle. is there.

Examples of the azide include hydrogen azide, lithium azide, sodium azide, lead azide, diphenyl phosphate azide and the like.
Examples of the organic nitro compound include nitromethane, nitropropane, nitrobutane, nitrobenzene, dinitrobenzene, nitrotoluene, dinitrotoluene, nitropyridine, and dinitropyridine.
Examples of the pyridine N-oxide compound include pyridine N-oxide, 4- (dimethylamino) pyridine N-oxide, 2,6 dimethylpyridine N-oxide, and 2,6 dichloropyridine N-oxide.
Examples of the alkylamine N-oxide compound include N, N-dimethyloctylamine N-oxide, N, N-dimethyldecylamine N-oxide, N, N-dodecylamine N-oxide, dimethyllaurylamine N-oxide, N, N-dimethylaniline N-oxide, N-methylmorpholine N-oxide and the like can be mentioned.

Among organic nitro compounds, azide compounds, pyridine N-oxide compounds, alkylamine N-oxide compounds and tetramethylpiperidine N-oxyl compounds, azides are preferred, and lithium azide and sodium azide are more preferred.

The concentration in the non-aqueous electrolyte of at least one compound selected from the group consisting of organic nitro compounds, azide compounds, and organic nitro compounds is too small to show the effect of addition. In view of the decrease, 0.01% by mass to 10% by mass is preferable, and 0.1% by mass to 5% by mass is more preferable.

The nonaqueous electrolyte used in the present invention may further contain a compound represented by the general formula (2) in order to enhance storage stability.

(Wherein R ⁵ to R ⁹ are each independently a hydrogen atom, a halogen atom, a nitrile group, a nitro group, an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, or 5 carbon atoms) A cycloalkyl group having 12 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, an oxyalkyl group having 1 to 12 carbon atoms, an acyl group having 1 to 12 carbon atoms, or —SiR R ¹² represents a group represented by R ¹³ R ¹⁴ , and R ¹⁰ to R ¹⁴ each independently represents an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, or a group having 5 to 12 carbon atoms. Represents a cycloalkyl group, an aryl group having 6 to 12 carbon atoms, or an aralkyl group having 7 to 12 carbon atoms, and X ¹ represents an m-valent alkyl group having 1 to 12 carbon atoms, 2 to 12 carbon atoms. An alkenyl group of A cycloalkyl group having 5 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, or an oxyalkyl group having 1 to 12 carbon atoms, and m is 1 to 3 Represents a number.)

Examples of the alkyl group having 1 to 12 carbon atoms include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, Examples include isopropyl group, isobutyl group, s-butyl group, t-butyl group, isopentyl group, neopentyl group, 1-methylbutyl group, isohexyl group, 2-ethylhexyl group, and 2-methylhexyl group.
Examples of the alkenyl group having 2 to 12 carbon atoms include vinyl, allyl, 1-butenyl, 2-butenyl, 3-butenyl, 1,3-butadienyl, 1-methylvinyl, 2- Butenyl, 3-butenyl, 1,3-butadienyl, 1-methylvinyl, 2-methylvinyl, 1-methylallyl, 1,1-dimethylallyl, pentenyl, hexenyl, heptenyl, octenyl Group, nonenyl group, decenyl group, undecenyl group, dodecenyl group and the like.
Examples of the cycloalkyl group having 5 to 12 carbon atoms include a cyclopentyl group, a cyclohexyl group, and a 2-norbornyl group. Examples of the aryl group having 6 to 12 carbon atoms include a cyclopentyl group, a cyclohexyl group, and a 2-norbornyl group.
Examples of the aryl group having 6 to 12 carbon atoms include phenyl, biphenyl, naphthyl, tolyl, xylyl, mesityl, and ethylphenyl groups.
Examples of the aralkyl group having 7 to 12 carbon atoms include benzyl group, phenylethyl group, phenylpropyl group, tolylmethyl group, tolylethyl group, tolylpropyl group, xylylmethyl group, xylylethyl group, xylylpropyl group and the like.
Examples of the oxyalkyl group having 1 to 12 carbon atoms include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, octyloxy group, decyloxy group and the like.
Examples of the acyl group having 1 to 12 carbon atoms include methanoyl group, ethanoyl group, propanoyl group, butanoyl group, pentanoyl group, hexanoyl group, heptanoyl group, octanoyl group, nonanoyl group, decanoyl group, undecanoyl group, dodecanoyl group and the like. It is done.

As the compound represented by the general formula (2), for example, the following compound No. 6-1 to No. 6-15.

In the compound represented by the general formula (2), m = 1 is preferable from the viewpoint of ease of synthesis. R ⁵ to R ⁹ are preferably a hydrogen atom, a methyl group, or an ethyl group, and more preferably a hydrogen atom, from the viewpoint of easy availability of raw materials. R ¹⁰ to R ¹⁴ are preferably a hydrogen atom, a methyl group, or an ethyl group, more preferably a methyl group, from the viewpoint of ease of synthesis.
The amount of the compound represented by the general formula (2) added to the non-aqueous electrolyte is preferably 0.1% by mass to 10% by mass, more preferably 0.1% by mass to 7.0% by mass, It is more preferably from 5% by mass to 7.0% by mass, and most preferably from 1% by mass to 5% by mass. When the content is less than 0.1% by mass, a sufficient effect cannot be exerted. When the content is more than 10% by mass, the increase effect corresponding to the addition amount is not seen, but the battery performance is reduced. There is.

There is no limitation in the timing which mix | blends the compound represented by General formula (2) with a nonaqueous electrolyte, and either the metal salt or the compound represented by General formula (1) is represented by General formula (2). After mixing with the compound, other materials can be mixed, and after mixing the compound represented by the general formula (2) with a material other than the metal salt and the compound represented by the general formula (1) A non-aqueous electrolyte can also be prepared by blending the metal salt and the general formula (1).

The non-aqueous electrolyte may contain known additives such as an electrode film forming agent, an antioxidant, a flame retardant, and an overcharge preventing agent in order to improve battery life and safety. When these additives are used, the concentration in the non-aqueous electrolyte is too small to exert the effect of addition, and when the concentration is too large, the characteristics of the non-aqueous electrolyte secondary battery may be adversely affected. 01% by mass to 10% by mass is preferable, and 0.1% by mass to 5% by mass is more preferable.

<Separator>
In the nonaqueous electrolyte secondary battery of the present invention, it is preferable to use a separator between the positive electrode and the negative electrode. As the separator, a commonly used polymer microporous film can be used without particular limitation. Examples of the film include polyethylene, polypropylene, polyvinylidene fluoride, polyvinylidene chloride, polyacrylonitrile, polyacrylamide, polytetrafluoroethylene, polysulfone, polyethersulfone, polycarbonate, polyamide, polyimide, polyethylene oxide and polypropylene oxide. Films composed of ethers, various celluloses such as carboxymethylcellulose and hydroxypropylcellulose, polymer compounds mainly composed of poly (meth) acrylic acid and various esters thereof, derivatives thereof, copolymers and mixtures thereof. These films may be coated with ceramic materials such as alumina and silica, magnesium oxide, aramid resin, and polyvinylidene fluoride. That.
These films can be used alone, and can be used as a multilayer film by superposing these films. Furthermore, various additives can be used for these films, and the kind and content thereof are not particularly limited. Among these films, a film made of polyethylene, polypropylene, polyvinylidene fluoride, or polysulfone is preferably used for a secondary battery manufactured by a method for manufacturing a secondary battery.

These films are made microporous so that the nonaqueous electrolyte is soaked and ions are easily transmitted. The microporosity method includes a phase separation method in which a polymer compound and a solvent solution are formed into a film while microphase separation is performed, and the solvent is extracted and removed to make it porous. The film is extruded and then heat treated, the crystals are arranged in one direction, and a “stretching method” or the like is performed by forming a gap between the crystals by stretching, and is appropriately selected depending on the film used.

The shape of the nonaqueous electrolyte secondary battery of the present invention is not particularly limited, and can be various shapes such as a coin shape, a cylindrical shape, a square shape, and a laminate shape. FIG. 1 shows an example of a coin-type battery of the nonaqueous electrolyte secondary battery of the present invention, and FIGS. 2 and 3 show examples of a cylindrical battery, respectively.

In the coin-type non-aqueous electrolyte secondary battery 10 shown in FIG. 1, 1 is a positive electrode capable of releasing lithium ions, 1a is a positive electrode current collector, 2 is a negative electrode capable of inserting and extracting lithium ions released from the positive electrode, and 2a is A negative electrode current collector, 3 is a nonaqueous electrolyte, 4 is a positive electrode case made of stainless steel, 5 is a negative electrode case made of stainless steel, 6 is a gasket made of polypropylene, and 7 is a separator made of polyethylene.

2 and 3, in the cylindrical nonaqueous electrolyte secondary battery 10 ', 11 is a negative electrode, 12 is a negative electrode current collector, 13 is a positive electrode, 14 is a positive electrode current collector, 15 is a nonaqueous electrolyte, 16 is a separator, 17 is a positive terminal, 18 is a negative terminal, 19 is a negative electrode plate, 20 is a negative electrode lead, 21 is a positive electrode plate, 22 is a positive electrode lead, 23 is a case, 24 is an insulating plate, 25 is a gasket, 26 is a safety valve 27 are PTC elements.

<External packaging>
As an exterior member of the nonaqueous electrolyte secondary battery of the present invention, a laminate film or a metal container can be used. The thickness of the exterior member is usually 0.5 mm or less, preferably 0.5 mm or less. Examples of the shape of the exterior member include a flat type (thin type), a square type, a cylindrical type, a coin type, and a button type.

As the laminate film, a multilayer film having a metal layer between resin films can also be used. The metal layer is preferably an aluminum foil or an aluminum alloy foil for weight reduction. For the resin film, for example, a polymer material such as polypropylene, polyethylene, nylon, or polyethylene terephthalate can be used. The laminate film can be formed into the shape of an exterior member by performing heat sealing.

The metal container can be formed of, for example, stainless steel, aluminum, aluminum alloy, or the like. As the aluminum alloy, an alloy containing elements such as magnesium, zinc, and silicon is preferable. In aluminum or an aluminum alloy, by setting the content of transition metals such as iron, copper, nickel, and chromium to 1% or less, long-term reliability and heat dissipation in a high temperature environment can be dramatically improved.

As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment. The present invention can be implemented in various forms without departing from the gist of the present invention, with modifications and improvements that can be made by those skilled in the art.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, the present invention is not limited to the following examples. In the examples, “parts” and “%” are based on mass unless otherwise specified. The sulfur content of the sulfur-modified organic compound was calculated by elemental analysis using a CHN analyzer (Elementor VARI MICRO cube) that can analyze sulfur and oxygen.

<Production Example 1> Production of sulfur-modified polyacrylonitrile (A-1) 10 parts by mass of polyacrylonitrile powder (manufactured by Sigma-Aldrich) and 30 parts by mass of sulfur powder (manufactured by Sigma-Aldrich, average particle diameter 200 μm) classified by a sieve having an opening diameter of 30 μm The parts were mixed using a mortar. Referring to the examples of JP2013-054957A, this mixture was accommodated in a cylindrical glass tube with a bottom, and the lower part of the glass tube was placed in a crucible type electric furnace while removing hydrogen sulfide generated under a nitrogen stream. Heated at 400 ° C. for 1 hour. After cooling, the product was placed in a glass tube oven and heated at 250 ° C. for 3 hours with vacuum suction to remove elemental sulfur. The obtained sulfur-modified product was pulverized using a ball mill and classified with a sieve to obtain sulfur-modified polyacrylonitrile having an average particle size of 10 μm. The sulfur content was 38.4% by mass.

<Production Example 2> Sulfur-modified pitch compound (A-2)
100 parts by weight of coal pitch (coal tar, manufactured by Yoshida Refinery) and 500 parts by weight of elemental sulfur (manufactured by Sigma Aldrich, average particle size 200 μm) are used as the pitch compound, in accordance with Example 1 of JP2012-099342A The reaction was carried out to obtain a reaction product. The obtained reaction product was pulverized to obtain sulfur-modified pitch compound A-2 having an average particle size of 15 μm. The sulfur content was 32.5% by mass.

<Production Example 3> Sulfur-modified polynuclear aromatic compound (A-3)
100 parts by mass of anthracene (manufactured by Tokyo Chemical Industry) and 500 parts by mass of elemental sulfur (manufactured by Sigma-Aldrich, average particle diameter 200 μm) are used as the sulfur-modified polynuclear aromatic ring compound, and in accordance with Reference Example 1 of JP2012-150934A Reaction was performed to obtain a reaction product. The obtained reaction product was pulverized to obtain a sulfur-modified polynuclear aromatic compound A-3 having an average particle size of 16 μm. The sulfur content was 47.7% by mass.

<Example 1>
<Preparation of positive electrode>
92.0 parts by mass of the sulfur-modified polyacrylonitrile (A-1) produced in Production Example 1 as a positive electrode active material, 3.5 parts by mass of acetylene black (manufactured by Denki Kagaku Kogyo Co., Ltd.) as a conductive auxiliary agent, and carbon nanotubes ( Showa Denko Co., Ltd., trade name VGCF) 1.5 parts by mass, and styrene-butadiene rubber (40% by mass aqueous dispersion, Nippon Zeon Co., Ltd.) 1.5 parts by mass (solid content) and sodium carboxymethyl cellulose as binder 1.5 parts by mass (manufactured by Daicel Finechem Co., Ltd.) was added to 100 parts by mass of water as a solvent, and dispersed using a rotation / revolution mixer to obtain an electrode mixture paste as a slurry.
The electrode mixture paste was applied to a current collector made of carbon-coated aluminum foil (thickness: 22 μm) by a doctor blade method, and allowed to stand at 90 ° C. for 3 hours to dry. Thereafter, this electrode was cut into a predetermined size (disc shape), and further vacuum-dried at 150 ° C. for 2 hours immediately before use to produce a positive electrode.
<Preparation of non-aqueous electrolyte>
LiPF ₆ was dissolved at a concentration of 1.0 mol / L in a mixed solvent composed of 50% by volume of ethylene carbonate and 50% by volume of diethyl carbonate to prepare an electrolyte solution. This is followed by compound no. 1.0% by mass of 2-1 was added to obtain a non-aqueous electrolyte.
<Battery assembly>
The disk-shaped positive electrode obtained above and lithium metal having a thickness of 500 μm cut into a disk shape were used as a negative electrode, and the glass filter was held as a separator and held in a case. Thereafter, the previously prepared non-aqueous electrolyte was poured into the case, sealed and sealed with a caulking machine, and the non-aqueous electrolyte secondary battery of Example 1 (metal sulfur secondary battery, φ20 mm, thickness 3.2 mm) Coin type).

<Example 2>
Compound No. 1 was added to the non-aqueous electrolyte of Example 1. Instead of adding 1.0% by mass of 2-1, compound no. A nonaqueous electrolyte secondary battery of Example 2 was produced in the same manner as in Example 1, except that 4% by mass of 4-7 was added.

<Example 3>
Compound No. 1 was added to the non-aqueous electrolyte of Example 1. Instead of adding 1.0% by mass of 2-1, compound no. Compound No. 5-4 in which the substitution positions are α and α ′ positions on the thiophene ring. A nonaqueous electrolyte secondary battery of Example 3 was produced in the same manner as in Example 1 except that 1.0% by mass of 5-4A was added.

<Example 4>
A nonaqueous electrolyte secondary battery of Example 4 was produced in the same manner as in Example 1, except that 0.1% by mass of lithium nitrate was further added to the nonaqueous electrolyte of Example 1.

<Example 5>
Compound No. 1 was added to the non-aqueous electrolyte of Example 1. Instead of adding 1.0% by mass of 2-1, compound no. A nonaqueous electrolyte secondary battery of Example 5 was produced in the same manner as in Example 1 except that 1.0% by mass of 4-7 and 0.1% by mass of lithium nitrate were added.

<Example 6>
Compound No. 1 was added to the non-aqueous electrolyte of Example 1. Instead of compound 2-1, compound no. A nonaqueous electrolyte secondary battery of Example 6 was produced in the same manner as in Example 1, except that 1.0% by mass of 5-4A and 0.1% by mass of lithium nitrate were added.

<Example 7>
The same procedure as in Example 1 was performed except that the sulfur-modified pitch compound (A-2) was used instead of the sulfur-modified polyacrylonitrile (A-1) as the positive electrode active material in Example 1. A water electrolyte secondary battery was produced.

<Example 8>
Example 8 was carried out in the same manner as in Example 1, except that the sulfur-modified polynuclear aromatic compound (A-3) was used instead of sulfur-modified polyacrylonitrile (A-1) as the positive electrode active material of Example 1. A non-aqueous electrolyte secondary battery was prepared.

<Example 9>
Compound No. 1 was added to the non-aqueous electrolyte of Example 1. Instead of adding 1.0% by mass of 2-1, compound no. A nonaqueous electrolyte secondary battery of Example 9 was produced in the same manner as in Example 1, except that 0.5% by mass of 2-1 and 0.5% by mass of compound 6-1 were added.

<Example 10>
Compound No. 1 was added to the non-aqueous electrolyte of Example 1. Instead of adding 1.0% by mass of 2-1, compound no. A nonaqueous electrolyte secondary battery of Example 10 was produced in the same manner as in Example 1, except that 0.5% by mass of 4-7 and 0.5% by mass of Compound 6-1 were added.

<Example 11>
Compound No. 1 was added to the non-aqueous electrolyte of Example 1. Instead of adding 1.0% by mass of 2-1, compound no. A nonaqueous electrolyte secondary battery of Example 11 was produced in the same manner as in Example 1, except that 0.5% by mass of 2-1 and 0.5% by mass of vinylene carbonate (VC) were added.

<Example 12>
Compound No. 1 was added to the non-aqueous electrolyte of Example 1. Instead of adding 1.0% by mass of 2-1, compound no. A nonaqueous electrolyte secondary battery of Example 12 was produced in the same manner as in Example 1, except that 0.5% by mass of 4-7 and 0.5% by mass of vinylene carbonate (VC) were added.

<Example 13>
Compound No. 1 was added to the non-aqueous electrolyte of Example 1. Instead of adding 1.0% by mass of 2-1, compound no. A nonaqueous electrolyte secondary battery of Example 13 was produced in the same manner as in Example 1 except that 0.5% by mass of 2-1 and 0.5% by mass of fluoroethylene carbonate (FEC) were added.

<Example 14>
Compound No. 1 was added to the non-aqueous electrolyte of Example 1. Instead of adding 1.0% by mass of 2-1, compound no. A nonaqueous electrolyte secondary battery of Example 14 was produced in the same manner as in Example 1, except that 0.5% by mass of 4-7 and 0.5% by mass of fluoroethylene carbonate (FEC) were added.

<Example 15>
Instead of using an electrolyte solution prepared by dissolving LiPF ₆ at a concentration of 1.0 mol / L in a mixed solvent composed of 50% by volume of ethylene carbonate and 50% by volume of diethyl carbonate in the nonaqueous electrolyte of Example 1, 1,3- Except for using an electrolyte solution in which lithium bis (trifluoromethanesulfonyl) imide (LiTFSI) was dissolved at a concentration of 1.0 mol / L in a mixed solvent composed of 50% by volume of dioxolane and 50% by volume of 1,2-dimethoxyethane, A nonaqueous electrolyte secondary battery of Example 15 was produced in the same manner as in Example 1.

<Example 16>
To the non-aqueous electrolyte of Example 15, compound No. Instead of adding 1.0% by mass of 2-1, compound no. A nonaqueous electrolyte secondary battery of Example 16 was produced in the same manner as in Example 15, except that 1.0% by mass of 4-7 was added.

<Example 17>
To the non-aqueous electrolyte of Example 15, compound No. Instead of adding 1.0% by mass of 2-1, compound no. A nonaqueous electrolyte secondary battery of Example 17 was produced in the same manner as in Example 15 except that 1.0% by mass of 5-4A was added.

<Example 18>
A nonaqueous electrolyte secondary battery of Example 18 was produced in the same manner as in Example 15, except that 0.1% by mass of lithium nitrate was further added to the nonaqueous electrolyte of Example 15.

<Example 19>
A nonaqueous electrolyte secondary battery of Example 19 was produced in the same manner as in Example 15, except that 0.1% by mass of lithium nitrate was further added to the nonaqueous electrolyte of Example 16.

<Example 20>
A nonaqueous electrolyte secondary battery of Example 20 was produced in the same manner as in Example 15, except that 0.1% by mass of lithium nitrate was further added to the nonaqueous electrolyte of Example 17.

<Example 21>
To the non-aqueous electrolyte of Example 15, compound No. Instead of adding 1.0% by mass of 2-1, compound no. A nonaqueous electrolyte secondary battery of Example 21 was produced in the same manner as in Example 15, except that 0.5% by mass of 2-1 and 0.5% by mass of vinylene carbonate were added.

<Example 22>
To the non-aqueous electrolyte of Example 15, compound No. Instead of adding 1.0% by mass of 2-1, compound no. A nonaqueous electrolyte secondary battery of Example 22 was produced in the same manner as in Example 15, except that 0.5% by mass of 4-7 and 0.5% by mass of vinylene carbonate were added.

<Example 23>
To the non-aqueous electrolyte of Example 15, compound No. Instead of adding 1.0% by mass of 2-1, compound no. A nonaqueous electrolyte secondary battery of Example 23 was produced in the same manner as in Example 15, except that 2-1 was added by 0.5 mass% and fluoroethylene carbonate was added by 0.5 mass%.

<Example 24>
To the non-aqueous electrolyte of Example 15, compound No. Instead of adding 1.0% by mass of 2-1, compound no. A nonaqueous electrolyte secondary battery of Example 24 was produced in the same manner as in Example 15, except that 0.5% by mass of 4-7 and 0.5% by mass of fluoroethylene carbonate were added.

<Example 25>
Instead of using an electrolyte solution in which LiPF ₆ was dissolved at a concentration of 1.0 mol / L in a mixed solvent composed of 50% by volume of ethylene carbonate and 50% by volume of diethyl carbonate in the nonaqueous electrolyte of Example 7, 1,3- Except for using an electrolyte solution in which lithium bis (trifluoromethanesulfonyl) imide (LiTFSI) was dissolved at a concentration of 1.0 mol / L in a mixed solvent composed of 50% by volume of dioxolane and 50% by volume of 1,2-dimethoxyethane, A nonaqueous electrolyte secondary battery of Example 26 was produced in the same manner as in Example 7.

<Example 26>
Instead of using an electrolyte solution in which LiPF ₆ was dissolved at a concentration of 1.0 mol / L in a mixed solvent composed of 50% by volume of ethylene carbonate and 50% by volume of diethyl carbonate in the nonaqueous electrolyte of Example 8, 1,3- Except for using an electrolyte solution in which lithium bis (trifluoromethanesulfonyl) imide (LiTFSI) was dissolved at a concentration of 1.0 mol / L in a mixed solvent composed of 50% by volume of dioxolane and 50% by volume of 1,2-dimethoxyethane, A nonaqueous electrolyte secondary battery of Example 26 was produced in the same manner as in Example 7.

<Comparative Example 1>
Compound No. 1 was added to the non-aqueous electrolyte of Example 1. A nonaqueous electrolyte secondary battery of Comparative Example 1 was produced in the same manner as in Example 1 except that 2-1 was not added.

<Comparative example 2>
To the non-aqueous electrolyte of Example 7, compound No. A nonaqueous electrolyte secondary battery of Comparative Example 2 was produced in the same manner as in Example 7, except that 2-1 was not added.

<Comparative Example 3>
To the non-aqueous electrolyte of Example 8, compound No. A nonaqueous electrolyte secondary battery of Comparative Example 3 was produced in the same manner as in Example 8, except that 2-1 was not added.

<Comparative Example 4>
Compound No. 1 was added to the non-aqueous electrolyte of Example 1. A nonaqueous electrolyte secondary battery of Comparative Example 4 was produced in the same manner as in Example 1, except that 1.0% by mass of vinylene carbonate (VC) was added instead of adding 1.0% by mass of 2-1. .

<Comparative Example 5>
Compound No. 1 was added to the non-aqueous electrolyte of Example 1. A nonaqueous electrolyte secondary battery of Comparative Example 3 was produced in the same manner as in Example 1, except that 0.1% by mass of lithium nitrate was added instead of adding 1.0% by mass of 2-1.

<Comparative Example 6>
Compound No. 1 was added to the non-aqueous electrolyte of Example 1. A nonaqueous electrolyte secondary battery of Comparative Example 6 was produced in the same manner as in Example 1, except that 1.0% by mass of fluoroethylene carbonate was added instead of adding 1.0% by mass of 2-1.

<Comparative Example 7>
To the non-aqueous electrolyte of Example 15, compound No. A nonaqueous electrolyte secondary battery of Comparative Example 7 was produced in the same manner as in Example 15 except that 2-1 was not added.

<Comparative Example 8>
To the nonaqueous electrolyte of Example 25, Compound No. A nonaqueous electrolyte secondary battery of Comparative Example 8 was produced in the same manner as in Example 25 except that 2-1 was not added.

<Comparative Example 9>
To the nonaqueous electrolyte of Example 26, Compound No. A nonaqueous electrolyte secondary battery of Comparative Example 9 was produced in the same manner as in Example 26 except that 2-1 was not added.

<Comparative Example 10>
To the non-aqueous electrolyte of Example 15, compound No. A nonaqueous electrolyte secondary battery of Comparative Example 10 was produced in the same manner as in Example 15 except that 1.0% by mass of vinylene carbonate (VC) was added instead of adding 1.0% by mass of 2-1. .

<Comparative Example 11>
To the non-aqueous electrolyte of Example 15, compound No. A nonaqueous electrolyte secondary battery of Comparative Example 11 was produced in the same manner as in Example 15 except that 1.0% by mass of fluoroethylene carbonate (FEC) was added instead of 1.0% by mass of 2-1 did.

<Comparative Example 12>
To the non-aqueous electrolyte of Example 15, compound No. A nonaqueous electrolyte secondary battery of Comparative Example 12 was produced in the same manner as in Example 15 except that 1.0% by mass of lithium nitrate was added instead of adding 1.0% by mass of 2-1.

<Comparative Example 13>
To the non-aqueous electrolyte of Example 15, compound No. The nonaqueous electrolyte of Comparative Example 13 was prepared in the same manner as in Example 15 except that 0.5% by mass of lithium nitrate and 0.5% by mass of fluoroethylene carbonate were added instead of adding 1.0% by mass of 2-1. A secondary battery was produced.

<Battery evaluation 1>
The nonaqueous electrolyte secondary batteries of Examples 1 to 8 and Comparative Examples 1 to 5 were placed in a constant temperature bath at 25 ° C., the charge end voltage was 3.0 V, the discharge end voltage was 1.0 V, and the charge rate was 0.1 C. The charge / discharge test at a discharge rate of 0.1 C was performed for 5 cycles. Thereafter, the sample was placed in a thermostatic chamber at −10 ° C., a charge / discharge test of 100 cycles was performed at a charge rate of 0.3 C and a discharge rate of 0.3 C, and the discharge capacity was measured. This discharge capacity was set to L1. The unit is mAh / g, and the results are shown in Table 1.

<Battery evaluation 2>
The nonaqueous electrolyte secondary batteries of Examples 1 to 8 and Comparative Examples 1 to 5 were placed in a constant temperature bath at 25 ° C., the charge end voltage was 3.0 V, the discharge end voltage was 1.0 V, and the charge rate was 0.1 C. Then, a charge / discharge test at a discharge rate of 0.1 C was performed for 5 cycles, followed by a charge / discharge test of 150 cycles at a charge rate of 1.0 C and a discharge rate of 1.0 C to measure the discharge capacity. This discharge capacity was set to L2. The unit is mAh / g, and the results are shown in Table 1.

<Battery evaluation 3>
The nonaqueous electrolyte secondary batteries of Examples 1 to 8 and Comparative Examples 1 to 5 were placed in a constant temperature bath at 25 ° C., the charge end voltage was 3.0 V, the discharge end voltage was 1.0 V, and the charge rate was 0.1 C. Then, a charge / discharge test at a discharge rate of 0.1 C was performed for 5 cycles, and then a charge test at a charge rate of 0.1 C was performed once. Then, it put into a 45 degreeC thermostat and preserve | saved for two weeks. Furthermore, it moved to the 25 degreeC thermostat, the charge end voltage was set to 3.0V, the discharge end voltage was set to 1.0V, and the charge / discharge test of charge rate 0.1C and discharge rate 0.1C was performed 3 cycles. This discharge capacity was set to L3. The unit is mAh / g, and the results are shown in Table 1.

From the discharge capacity L2 shown in Table 1, a positive electrode having a sulfur-modified organic compound, a negative electrode having a metal selected from the group consisting of alkali metals and alkaline earth metals, at least one of the general formula (1), and an alkali metal The nonaqueous electrolyte secondary battery of the present invention comprising a nonaqueous electrolyte containing at least one metal salt selected from the group consisting of a salt or an alkaline earth metal salt is after 150 cycles compared to the secondary battery shown in the comparative example. The capacity of was large.

Further, from the discharge capacities L1 and L3 shown in Table 1, the nonaqueous electrolyte secondary battery of the present invention has both excellent charge / discharge characteristics at low temperatures and excellent high-temperature storage stability.

According to the present invention, it is possible to provide a non-aqueous electrolyte secondary battery having a high capacity even after repeated charging and discharging. In addition, it is possible to provide a nonaqueous electrolyte secondary battery that is excellent in capacity characteristics after storage at high temperatures.

DESCRIPTION OF SYMBOLS 1 Positive electrode 1a Positive electrode collector 2 Negative electrode 2a Negative electrode collector 3 Nonaqueous electrolyte 4 Positive electrode case 5 Negative electrode case 6 Gasket 7 Separator 10 Coin type nonaqueous electrolyte secondary battery 10 'Cylindrical type nonaqueous electrolyte secondary battery 11 Negative electrode 12 Negative electrode current collector 13 Positive electrode 14 Positive electrode current collector 15 Nonaqueous electrolyte 16 Separator 17 Positive electrode terminal 18 Negative electrode terminal 19 Negative electrode plate 20 Negative electrode lead 21 Positive electrode plate 22 Positive electrode lead 23 Case 24 Insulating plate 25 Gasket 26 Safety valve 27 PTC element

Claims

A positive electrode containing a sulfur-modified organic compound; a negative electrode containing at least one metal selected from the group consisting of alkali metals and alkaline earth metals; at least one compound represented by formula (1); and an alkali metal A non-aqueous electrolyte secondary battery comprising: a non-aqueous electrolyte containing at least one metal salt selected from the group consisting of a salt and an alkaline earth metal salt.

(Wherein R 1 to R 3 each independently represents a hydrocarbon group having 1 to 10 carbon atoms, and R 4 represents an n-valent hydrocarbon group having 1 to 10 carbon atoms, or an oxygen atom or sulfur) (It represents an n-valent hydrocarbon group having 1 to 10 carbon atoms and containing at least one atom, and n represents an integer of 1 to 6.)
The nonaqueous electrolyte secondary battery according to claim 1, wherein the content of the compound represented by the general formula (1) is 0.01 mass% to 20 mass% in the nonaqueous electrolyte.
R 4 of the compound represented by the general formula (1) is an unsaturated hydrocarbon group having 2 to 10 carbon atoms, a heteroaromatic group containing sulfur having 2 to 10 carbon atoms, or the number of carbon atoms containing sulfur The nonaqueous electrolyte secondary battery according to claim 1 or 2, wherein the nonaqueous electrolyte secondary battery represents 2 to 10 aliphatic hydrocarbon groups and n is 2.
The nonaqueous electrolyte further comprises at least one compound selected from the group consisting of azide, organic nitro compound, pyridine N-oxide compound, alkylamine N-oxide compound, and tetramethylpiperidine N-oxyl. 4. The nonaqueous electrolyte secondary battery according to any one of items 1 to 3.
The total content of the compound selected from the group consisting of azide, organic nitro compound, pyridine N-oxide compound, alkylamine N-oxide compound and tetramethylpiperidine N-oxyl is 0.01% by mass or more in the non-aqueous electrolyte. The nonaqueous electrolyte secondary battery according to claim 4, wherein the nonaqueous electrolyte secondary battery is 10% by mass.
The nonaqueous electrolyte secondary battery according to any one of claims 1 to 5, wherein the nonaqueous electrolyte further includes at least one compound represented by the general formula (2).

(Wherein R 5 to R 9 each independently represents a hydrogen atom, a halogen atom, a nitrile group, a nitro group, an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 5 to 12 carbon atoms, or a carbon atom) Represented by an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, an oxyalkyl group having 1 to 12 carbon atoms, an acyl group having 1 to 12 carbon atoms, or —SiR 12 R 13 R 14 R 10 to R 14 each independently represents an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, a cycloalkyl group having 5 to 12 carbon atoms, or 6 carbon atoms. Represents an aryl group of ˜12 or an aralkyl group of 7 to 12 carbon atoms, X 1 represents an m-valent hydrocarbon group, and m represents an integer of 1 to 3.)
The nonaqueous electrolyte secondary battery according to any one of claims 1 to 6, wherein the negative electrode contains lithium or sodium.
The nonaqueous electrolyte secondary battery according to any one of claims 1 to 7, wherein the sulfur-modified organic compound is sulfur-modified polyacrylonitrile.