JP2010033875A - Positive electrode composite containing organic sulfur compound, and all-solid secondary battery using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-capacity, safe secondary battery, in regard to a positive electrode composite containing an organic sulfur compound and an all-solid secondary battery using the same. <P>SOLUTION: The positive electrode composite contains an organic sulfur compound and a lithium ion conductive inorganic solid electrolyte. In the positive electrode composite described in claim 1, the organic sulfur compound is an organic disulfide compound, a carbon sulfide compound or their mixture. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a positive electrode mixture comprising an organic sulfur compound and an all-solid secondary battery using the same.

  In recent years, the demand for secondary batteries such as high-performance lithium batteries used in personal digital assistants, portable electronic devices, small household power storage devices, motorcycles powered by motors, electric vehicles, hybrid electric vehicles, etc. has increased. Yes.

  As the use of secondary batteries expands, various battery characteristics are required. One of the required battery characteristics is an increase in capacity. Various studies have been made to increase the capacity. For example, a high-capacity electrode material using a sulfur-based active material as a positive electrode active material has been studied (Patent Document 1).

  Examples of the sulfur-based active material include disulfide-based compounds. However, disulfide compounds undergo cleavage-polymerization of disulfide bonds due to oxidation-reduction reactions during charge and discharge, and the disulfide compounds are reduced in molecular weight during cleavage. Since the electrolyte of the lithium ion battery is liquid, the disulfide compound having a low molecular weight is eluted into the electrolytic solution, and there is a problem that cycle deterioration of charge / discharge characteristics is increased.

In addition to the above, there has been proposed an attempt to suppress elution and desorption during the reaction by using an electrode containing a polymer component into which a thiol group is introduced (Patent Document 2). However, an electrode including a polymer component into which a thiol group is introduced has a problem that processing is difficult and a manufacturing method is limited.
US Pat. No. 4,833,048 JP-A-6-163049

  An object of the present invention is to provide a high-capacity and safe secondary battery.

According to the present invention, the following positive electrode mixture and the like are provided.
1. A positive electrode mixture containing an organic sulfur compound and a lithium ion conductive inorganic solid electrolyte.
2. 2. The positive electrode mixture according to 1, wherein the organic sulfur compound is an organic disulfide compound, a carbon sulfide compound, or a mixture thereof.
3. The positive electrode mixture according to 1 or 2, wherein the lithium ion conductive inorganic solid electrolyte contains one or more elements selected from the group consisting of P, Si and B, Li and S.
4). Furthermore, the positive electrode compound material in any one of 1-3 containing a conductive support agent.
All solids comprising a positive electrode made of the positive electrode mixture according to any one of 5.1 to 4, a negative electrode, and a solid electrolyte layer made of a lithium ion conductive inorganic solid electrolyte sandwiched between the positive electrode and the negative electrode Secondary battery.
6). 6. The all solid state secondary battery according to 5, wherein the lithium ion conductive inorganic solid electrolyte of the solid electrolyte layer contains one or more elements selected from the group consisting of P, Si and B, Li and S.

  According to the present invention, a high-capacity and safe secondary battery can be provided.

The positive electrode mixture of the present invention contains an organic sulfur compound and a lithium ion conductive inorganic solid electrolyte.
The organic sulfur compound, which is a positive electrode active material, can repeatedly increase the capacity of a secondary battery by alternately repeating polymerization and monomerization during electrolytic oxidation and electrolytic reduction.

The organic sulfur compound is preferably an organic disulfide compound, a carbon sulfide compound, or a mixture thereof.
Examples of the organic disulfide compound include the following compounds.

Examples of the carbon sulfide compound include the following compounds.

The lithium ion conductive inorganic solid electrolyte is not particularly limited. For example, a material composed of an organic compound, an inorganic compound, or a mixture of an organic compound and an inorganic compound can be used, and preferably contains one or more elements selected from the group consisting of P, Si, and B, Li and S A lithium ion conductive inorganic solid electrolyte is used.
By using the lithium ion conductive inorganic solid electrolyte containing S as described above, the positive electrode mixture of the present invention contains sulfur in common between the organic sulfur compound and the lithium ion conductive inorganic solid electrolyte, which will be described later. During mixing, the organic sulfur compound and the lithium ion conductive inorganic solid electrolyte can be uniformly dispersed to facilitate mixing.

Among lithium ion conductive inorganic solid electrolytes, in particular, sulfide-based inorganic solid electrolytes are known to have higher ionic conductivity than other inorganic compounds, and inorganic solid electrolytes described in JP-A-4-202024 etc. Can be used. Specifically, an inorganic solid electrolyte in which Li ₃ PO ₄ , a halogen, and a halogen compound are appropriately added to an inorganic solid electrolyte composed of a combination of Li ₂ S and SiS ₂ , GeS ₂ , P ₂ S ₅ , B ₂ S _3. Can be used.

  Since lithium ion conductivity is high, lithium ion conduction generated from lithium sulfide and diphosphorus pentasulfide, or lithium sulfide and simple phosphorus and simple sulfur, as well as lithium sulfide, diphosphorus pentasulfide, simple phosphorus and / or simple sulfur It is preferable to use a conductive inorganic solid electrolyte. Hereinafter, a preferable solid electrolyte will be described.

The lithium ion conductive inorganic solid electrolyte can be produced from lithium sulfide and diphosphorus pentasulfide (P ₂ S ₅ ) and / or simple phosphorus and simple sulfur. Specifically, it can be produced by melting these raw materials and then rapidly cooling them. In addition, sulfide glass obtained by treating these raw materials by a mechanical milling method (hereinafter, sometimes referred to as MM method), or a heat-treated product thereof.

As lithium sulfide, those commercially available without limitation can be used, but those having high purity are preferable as described below.
Lithium sulfide has at least a total content of lithium salt of sulfur oxide of 0.15% by mass or less, preferably 0.1% by mass or less, and a content of lithium N-methylaminobutyrate of 0.15% by mass. Hereinafter, it is preferably 0.1% by mass or less. When the total content of the lithium salt of sulfur oxide is 0.15% by mass or less, the solid electrolyte obtained by the melt quenching method or the mechanical milling method described later is a glassy electrolyte (fully amorphous). That is, when the total content of the lithium salt of sulfur oxide exceeds 0.15% by mass, the obtained electrolyte is a crystallized product from the beginning, and the ionic conductivity of this crystallized product is low. Furthermore, even if the crystallized product is subjected to the following heat treatment, the crystallized product is not changed, and a lithium ion conductive inorganic solid electrolyte having a high ion conductivity cannot be obtained.

  Further, when the content of lithium N-methylaminobutyrate is 0.15% by mass or less, a deteriorated product of lithium N-methylaminobutyrate does not deteriorate the cycle performance of the lithium battery.

  Thus, in order to obtain a high ion conductive electrolyte, it is necessary to use lithium sulfide with reduced impurities.

The method for producing lithium sulfide used for producing the high ion conductive electrolyte is not particularly limited as long as it is a method that can reduce at least the impurities.
For example, it can also be obtained by purifying lithium sulfide produced by the following method.
Among the following production methods, the method a or b is particularly preferable.
a. A method in which lithium hydroxide and hydrogen sulfide are reacted at 0 to 150 ° C. in an aprotic organic solvent to produce lithium hydrosulfide, and this reaction solution is then desulfurized at 150 to 200 ° C. -330312).
b. A method of directly producing lithium sulfide by reacting lithium hydroxide and hydrogen sulfide at 150 to 200 ° C. in an aprotic organic solvent (Japanese Patent Laid-Open No. 7-330312).
c. A method of reacting lithium hydroxide and a gaseous sulfur source at a temperature of 130 to 445 ° C. (Japanese Patent Laid-Open No. 9-283156).

  There is no restriction | limiting in particular as a purification method of the lithium sulfide obtained as mentioned above. As a preferable purification method, for example, the method described in International Publication No. WO2005 / 40039 and the like can be mentioned.

  Specifically, the lithium sulfide obtained as described above is washed at a temperature of 100 ° C. or higher using an organic solvent. The organic solvent used for washing is preferably an aprotic polar solvent, and more preferably, the aprotic organic solvent used for lithium sulfide production and the aprotic polar organic solvent used for washing are the same. .

  Examples of the aprotic polar organic solvent preferably used for washing include aprotic polar organic compounds such as amide compounds, lactam compounds, urea compounds, organic sulfur compounds, cyclic organophosphorus compounds, Or it can use suitably as a mixed solvent. In particular, N-methyl-2-pyrrolidone (NMP) is selected as a good solvent.

  The amount of the organic solvent used for washing is not particularly limited, and the number of times of washing is not particularly limited, but is preferably 2 or more. Cleaning is preferably performed under an inert gas such as nitrogen or argon.

  The washed lithium sulfide is dried at a temperature equal to or higher than the boiling point of the organic solvent used for washing for 5 minutes or more, preferably about 2 to 3 hours or more under an inert gas stream such as nitrogen under normal pressure or reduced pressure. Thus, lithium sulfide suitably used in the present invention can be obtained.

P ₂ S ₅ can be used without particular limitation as long as it is industrially manufactured and sold. In place of P ₂ S ₅ , elemental phosphorus (P) and elemental sulfur (S) in a corresponding molar ratio can also be used. Simple phosphorus (P) and simple sulfur (S) can be used without particular limitation as long as they are industrially produced and sold.

  In the present invention, as the solid electrolyte, both a glassy solid electrolyte and a solid electrolyte containing a crystal component can be used. The type should be selected according to the required characteristics. Both may be used.

The mixing molar ratio of the lithium sulfide to diphosphorus pentasulfide or simple phosphorus and simple sulfur is usually 50:50 to 80:20, preferably 60:40 to 75:25.
Particularly preferably, it is about Li ₂ S: P ₂ S ₅ = 68: 32 to 74:26 (molar ratio).

  Examples of the method for producing a sulfide glass that is a glassy electrolyte include a melt quenching method and a mechanical milling method.

In the case of the melt quenching method, a predetermined amount of P ₂ S ₅ and Li ₂ S are mixed in a mortar, and the pellets are placed in a carbon-coated quartz tube and sealed in a vacuum. After reacting at a predetermined reaction temperature, the glass is put into ice and quenched to obtain a sulfide glass.

  The reaction temperature at this time is preferably 400 ° C to 1000 ° C, more preferably 800 ° C to 900 ° C. Moreover, reaction time becomes like this. Preferably it is 0.1 to 12 hours, More preferably, it is 1 to 12 hours. The quenching temperature of the reaction product is usually 10 ° C. or lower, preferably 0 ° C. or lower, and the cooling rate is about 1 to 10,000 K / sec, preferably 1 to 1000 K / sec.

In the case of the MM method, sulfide glass is obtained by mixing a predetermined amount of P ₂ S ₅ and Li ₂ S in a mortar and reacting for a predetermined time by a mechanical milling method.

  The mechanical milling method using the above raw materials can be reacted at room temperature. According to the MM method, since a glassy electrolyte can be produced at room temperature, there is an advantage that a raw material is not thermally decomposed and a glassy electrolyte having a charged composition can be obtained. Further, the MM method has an advantage that the glassy electrolyte can be made into fine powder simultaneously with the production of the glassy electrolyte.

  Although various types of pulverization methods can be used for the MM method, it is particularly preferable to use a planetary ball mill. The planetary ball mill can efficiently generate very high impact energy by rotating the platform while the pot rotates.

  Although the rotation speed and rotation time of the MM method are not particularly limited, the faster the rotation speed, the faster the glassy electrolyte production rate, and the longer the rotation time, the higher the conversion rate of the raw material into the glassy electrolyte.

The electrolyte thus obtained is a glassy electrolyte and usually has an ionic conductivity of about 1.0 × 10 ^{−5 to} 8.0 × 10 ⁻⁴ (S / cm).

  As conditions for the MM method, for example, when a planetary ball mill is used, the rotational speed may be set to several tens to several hundreds of revolutions / minute, and the treatment may be performed for 0.5 hours to 100 hours.

  Although specific examples of the sulfide glass by the melt quenching method and the MM method have been described above, manufacturing conditions such as temperature conditions and processing time can be appropriately adjusted according to the equipment used.

  Thereafter, the obtained sulfide glass is heat-treated at a predetermined temperature to produce a solid electrolyte containing a crystal component.

  The heat treatment temperature for producing such a solid electrolyte is preferably 190 ° C to 340 ° C, more preferably 195 ° C to 335 ° C, and particularly preferably 200 ° C to 330 ° C. When the temperature is lower than 190 ° C., it may be difficult to obtain a crystal with high ion conductivity. When the temperature is higher than 340 ° C., a crystal with low ion conductivity may be generated.

  The heat treatment time is preferably 3 to 240 hours, particularly preferably 4 to 230 hours, when the temperature is 190 ° C or higher and 220 ° C or lower. When the temperature is higher than 220 ° C and not higher than 340 ° C, 0.1 to 240 hours are preferable, 0.2 to 235 hours are particularly preferable, and 0.3 to 230 hours are more preferable. If the heat treatment time is shorter than 0.1 hour, it may be difficult to obtain a crystal with high ion conductivity. If the heat treatment time is longer than 240 hours, a crystal with low ion conductivity may be formed.

The lithium ion conductive inorganic solid electrolyte containing the crystal component thus obtained usually has an ionic conductivity of about 7.0 × 10 ^{−4 to} 5.0 × 10 ⁻³ (S / cm). It is.

This lithium ion conductive inorganic solid electrolyte has 2θ = 17.8 ± 0.3 deg, 18.2 ± 0.3 deg, 19.8 ± 0.3 deg, X-ray diffraction (CuKα: λ = 1.5418４), 21.8 ± 0.3 deg, 23.8 ± 0.3 deg, 25.9 ± 0.3 deg
It is preferable to have diffraction peaks at g, 29.5 ± 0.3 deg, 30.0 ± 0.3 deg. A solid electrolyte having such a crystal structure has extremely high lithium ion conductivity.

  The positive electrode mixture of the present invention can be produced by mixing the organic sulfur compound, which is the positive electrode active material, and the lithium ion conductive inorganic solid electrolyte at a predetermined ratio. As a ratio, it can use in the ratio of 20 wt%-95 wt% as solid weight% (wt%) of a positive electrode active material. More preferably, it is 50 wt%-90 wt%, and a more suitable ratio is 60 wt%-80 wt%. As a method of mixing, in addition to a method of mixing the dried powder with an agate mortar or the like, a method of directly adding to an organic solvent and mixing can be used.

In order to make electrons move smoothly in the active material, the positive electrode mixture of the present invention preferably further contains a conductive additive.
As the conductive aid, for example, a conductive material such as acetylene black, carbon black, and carbon nanotube, a conductive polymer such as polyaniline, polyacetylene, and polypyrrole, or a mixture thereof can be used.

The positive electrode of the all-solid-state secondary battery can be formed by applying a mixed liquid composed of the positive electrode mixture of the present invention and a solvent.
In the mixed solution, the positive electrode mixture of the present invention is not dissolved in a solvent. Since the specific gravity of the positive electrode mixture of the present invention is usually larger than the specific gravity of the solvent, it is usually precipitated in the above mixed solution, but when forming the positive electrode, the positive electrode mixture is uniformly dispersed by stirring or the like. It is preferable to use a mixed liquid.

  The solvent used in the mixed solution is preferably a solvent having low reactivity with the positive electrode mixture, but by treating the positive electrode mixture surface so that the positive electrode mixture does not react with the solvent, for example, by coating the surface of the positive electrode mixture, A solvent having high reactivity with the material can also be used.

The solvent is preferably an organic solvent, more preferably a hydrocarbon organic solvent, such as hexane, heptane, toluene, xylene, decalin, and the like.
Of these solvents, hexane, toluene, and xylene, which are low-boiling solvents, are preferable in consideration of the drying process after coating, but it is difficult to use a low-boiling solvent having a high evaporation rate in consideration of maintaining the mixed liquid. , Toluene, xylene and the like are preferable.

  The solvent used in the mixed solution is preferably dehydrated to reduce the water content. The water content of the solvent is usually 30 ppm or less, preferably 10 ppm or less, more preferably 1.0 ppm or less.

You may further add a binder to the liquid mixture which consists of a positive electrode compound material and a solvent.
The binder is not particularly limited as long as the reactivity with the positive electrode mixture is low, preferably a thermoplastic resin and a thermosetting resin, more preferably polysiloxane, polyalkylene glycol, polytetrafluoroethylene (PTFE), Polyvinylidene fluoride (PVDF), styrene butadiene rubber (SBR), styrene butadiene rubber / carboxymethyl cellulose (SBR / CMC), polyethylene oxide (PEO), branched PEO, polyphenylene oxide (PPO), PEO-PPO copolymer, branched PEO -PPO copolymer, alkylborane-containing polyether.
The binder is particularly preferably SBR or polyalkylene glycol from the viewpoint of ease of sheet formation, prevention of increase in interface resistance and prevention of reduction in charge / discharge capacity.

The all solid state secondary battery of the present invention includes a positive electrode made of the positive electrode mixture of the present invention, a negative electrode, and a solid electrolyte layer made of a lithium ion conductive inorganic solid electrolyte sandwiched between the positive electrode and the negative electrode.
In the all solid state secondary battery of the present invention, since the electrolyte layer is solid, leakage and evaporation of the electrolyte can be prevented. In addition, since the reactivity of the electrolyte layer with the electrode material is smaller than that of the organic electrolyte, and the possibility of a temperature increase associated with the reaction is small, the all solid state secondary battery of the present invention is excellent in safety.

  Moreover, since the electrolyte of the lithium ion battery is liquid, the electrolyte of the all-solid secondary battery of the present invention is solid, so that the organic sulfur compound of the positive electrode mixture that has been reduced in molecular weight by the cleavage reaction during charge and discharge Elution does not occur and cycle deterioration of charge / discharge characteristics can be suppressed.

The lithium ion conductive inorganic solid electrolyte contained in the solid electrolyte layer is preferably the same as the lithium ion conductive inorganic solid electrolyte contained in the positive electrode mixture.
In particular, by making the lithium ion conductive inorganic solid electrolyte contained in the solid electrolyte layer a lithium ion conductive inorganic solid electrolyte containing one or more elements selected from the group consisting of P, Si and B, Li and S, The positive electrode and the solid electrolyte layer contain sulfur atoms in common, and the chemical stability of the battery can be improved.

FIG. 1 is a schematic cross-sectional view showing an embodiment of an all solid state secondary battery according to the present invention.
In the all-solid-state secondary battery 1, a solid electrolyte layer 20 is sandwiched between a pair of electrodes composed of a positive electrode 10 and a negative electrode 30 made of the positive electrode mixture of the present invention. Current collectors 40 and 42 are provided on the positive electrode 10 and the negative electrode 30, respectively.

  The positive electrode 10 is made of the positive electrode mixture of the present invention, and can be produced by forming the positive electrode mixture of the present invention in a film shape on at least a part of the current collector 40. As the film forming method, in addition to the above-described method of forming the mixture of the positive electrode mixture and the solvent of the present invention by coating, for example, blasting method, aerosol deposition method, cold spray method, sputtering method, vapor phase growth A method, a pressure press method, a thermal spray method, or the like can also be used. By forming a film by such a method, the porosity of the positive electrode can be further reduced, and electron conduction, electron exchange, and ion conduction can be improved.

The solid electrolyte layer 20 can be manufactured by depositing a particulate lithium ion conductive inorganic solid electrolyte by, for example, a blast method or an aerosol deposition method. Also, a lithium ion conductive inorganic solid electrolyte can be formed by a cold spray method, a sputtering method, a vapor deposition method (chemical vapor deposition: CVD), a thermal spraying method, or the like.
Further, there is a method in which a solution in which a lithium ion conductive inorganic solid electrolyte is mixed with a solvent or a binder (such as a binder or a polymer compound) is applied and applied, and then the solvent is removed to form a film. Also, the solid electrolyte itself, solid electrolyte and binder (binder, polymer compound, etc.) and support (materials and compounds to reinforce the strength of the solid electrolyte layer and prevent short circuit of the solid electrolyte itself) are mixed -It is also possible to form a film by pressing the combined electrolyte under pressure.

Although a solvent will not be specifically limited if it does not have a bad influence on the performance of solid electrolyte, For example, a non-aqueous solvent is mentioned.
Examples of the non-aqueous solvent include solvents used in electrolyte solutions such as dry heptane, toluene, hexane, tetrahydrofuran (THF), N methylpyrrolidone, acetonitrile, dimethoxyethane, and dimethyl carbonate, and preferably have a water content. The solvent is 100 ppm or less, more preferably 50 ppm or less.

As the binder, a thermoplastic resin or a thermosetting resin can be used. For example, polysiloxane, polyalkylene glycol, polyethylene, polypropylene, polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), tetrafluoroethylene-hexafluoroethylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer ( FEP), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-chlorotrifluoroethylene copolymer, ethylene-tetrafluoroethylene copolymer ( ETFE resin), polychlorotrifluoroethylene (PCTFE), vinylidene fluoride-pentafluoropropylene copolymer, propylene-tetrafluoroethylene copolymer, ethylene -Chlorotrifluoroethylene copolymer (ECTFE), vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene copolymer, vinylidene fluoride-perfluoromethyl vinyl ether-tetrafluoroethylene copolymer, ethylene-acrylic acid copolymer (Na ⁺⁾ ion crosslinked product of polymer or the material, ethylene - (Na ⁺⁾ ion crosslinked product of methacrylic acid copolymer or the materials, ethylene - methyl acrylate copolymer or (Na ⁺⁾ ion crosslinked body, ethylene - can be given (Na ⁺⁾ ion crosslinked product of methyl methacrylate copolymer or the material.

  Among these, polysiloxane, polyalkylene glycol, polyvinylidene fluoride (PVDF), and polytetrafluoroethylene (PTFE) are preferable.

  The negative electrode 30 can be produced in the same manner as the positive electrode 10. As a negative electrode material used for preparation of the negative electrode 30, what is used as a negative electrode active material in the battery field | area can be used. For example, carbon materials, specifically artificial graphite, graphite carbon fiber, resin-fired carbon, pyrolytic vapor-grown carbon, coke, mesocarbon microbeads (MCMB), furfuryl alcohol resin-fired carbon, polyacene, pitch-based carbon Examples include fibers, vapor grown carbon fibers, natural graphite, and non-graphitizable carbon. Or it may be a mixture thereof. Preferably, it is artificial graphite. Moreover, the metal itself of metal lithium, metal indium, metal aluminum, or metal silicon, or the alloy which combined these metals with another element or compound can be used as a negative electrode material.

  The negative electrode material may be mixed with a conductive additive and / or a lithium ion conductive inorganic solid electrolyte in the same manner as the positive electrode mixture. The lithium ion conductive inorganic solid electrolyte used for the negative electrode material is preferably the same as the lithium ion conductive inorganic solid electrolyte used for the solid electrolyte layer.

As the current collectors 40 and 42, a plate or foil made of copper, magnesium, stainless steel, titanium, iron, cobalt, nickel, zinc, aluminum, germanium, indium, lithium, or an alloy thereof, or the like Can be used.
The current collectors 40 and 42 may be the same as or different from each other. For example, a copper foil may be used for the current collector 40 and an aluminum foil may be used for the current collector 42.

The all-solid-state secondary battery can be manufactured by bonding and joining the battery members described above. As a method of joining, there are a method of laminating each member, pressurizing and pressure bonding, a method of pressing through two rolls (roll to roll), and the like.
Moreover, you may join to the joining surface through the active material which has ion conductivity, and the adhesive material which does not inhibit ion conductivity.
In joining, heat fusion may be performed as long as the crystal structure of the solid electrolyte does not change.

The positive electrode mixture of the present invention can be used for an all-solid secondary battery.
The all-solid-state secondary battery of the present invention can be used as a battery for a portable information terminal, a portable electronic device, a small electric power storage device for home use, a motorcycle using a motor as a power source, an electric vehicle, a hybrid electric vehicle, or the like.

It is a schematic sectional drawing which shows one Embodiment of the all-solid-state lithium battery which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 All-solid-state secondary battery 10 Positive electrode 20 Solid electrolyte layer 30 Negative electrode 40,42 Current collector

Claims (6)

  A positive electrode mixture containing an organic sulfur compound and a lithium ion conductive inorganic solid electrolyte.   The positive electrode mixture according to claim 1, wherein the organic sulfur compound is an organic disulfide compound, a carbon sulfide compound, or a mixture thereof.   The positive electrode mixture according to claim 1 or 2, wherein the lithium ion conductive inorganic solid electrolyte contains one or more elements selected from the group consisting of P, Si and B, Li and S.   Furthermore, the positive electrode compound material in any one of Claims 1-3 containing a conductive support agent. A positive electrode comprising the positive electrode mixture according to any one of claims 1 to 4, a negative electrode,
An all solid state secondary battery comprising a solid electrolyte layer made of a lithium ion conductive inorganic solid electrolyte sandwiched between the positive electrode and the negative electrode.   The all-solid-state secondary battery according to claim 5, wherein the lithium ion conductive inorganic solid electrolyte of the solid electrolyte layer contains one or more elements selected from the group consisting of P, Si, and B, Li and S.

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