Solid electrolyte composition, solid electrolyte layer or electrode mixture, and lithium ion battery

Abstract

The present invention provides a solid electrolyte composition which contains (A) a sulfide solid electrolyte that contains lithium, phosphorus and sulfur, and (B) one or more compounds that are selected from among the compounds represented by formulae (1) to (3). (1): R11R12R13PO (2): (NR21R22)(NR23R24)(NR25R26)PO (3): (R31O)(R32O)(R33O)PO

Description

Solid electrolyte composition, solid electrolyte layer or electrode mixture, and lithium ion battery

[0001] The present invention relates to a solid electrolyte composition, a solid electrolyte layer or electrode mixture, and a lithium ion battery.

[0002] All-solid-state lithium-ion batteries are becoming increasingly popular due to their high level of safety and other reasons, and various studies are being conducted to improve their performance (e.g., Patent Document 1). In the manufacture of all-solid-state lithium-ion batteries, a solid electrolyte is sometimes applied in a slurry state, but conventional solid electrolytes have a problem of poor dispersibility in various organic solvents, resulting in insufficient coatability. To address this issue, dispersibility can be improved by using polar solvents such as butyl butyrate, but polar solvents may deteriorate the solid electrolyte, so there is a demand for solid electrolytes that are particularly highly dispersible in nonpolar solvents.

[0003] Japanese Patent Application Laid-Open No. 2020-166994

[0004] An object of the present invention is to provide a solid electrolyte composition that is excellent in dispersibility in non-polar organic solvents.

[0005] As a result of extensive research, the present inventors have found that the above problems can be solved by adding a compound having a specific structure to a solid electrolyte, and have thus completed the present invention. According to the present invention, the following solid electrolyte composition and the like are provided. 1. A solid electrolyte composition comprising: (A) a sulfide solid electrolyte containing lithium, phosphorus, and sulfur; and (B) one or more compounds selected from compounds represented by the following formulas (1) to (3). R １１ R １２ R １３ PO (1) (NR ２１ R ２２ ) (NR ２３ R ２４ ) (NR ２５ R ２６ ) PO (2) (R ３１ O) (R ３２ O) (R ３３ O)PO (3) (In formula (1), R １１ ~R １３ are each independently a hydrogen atom or a substituent RA, and R１１ ~R １３ At least one of R is a substituent group RA. ２１ and R ２２ , R ２３ and R ２４ , and R ２５ and R ２６ At least one pair of R are bonded to each other to form a substituted or unsubstituted saturated or unsaturated ring, or are not bonded to each other. ２１ ~R ２６ are each independently a hydrogen atom or a substituent RA, and R ２１ ~R ２６ At least one of R is a substituent group RA. ３１ ~R ３３ are each independently a hydrogen atom or a substituent RB, and R ３１ ~R ３３ At least one of the above is a substituent RB. The substituent RA is a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 50 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted monovalent heterocyclic group having 5 to 50 ring atoms. The substituent RB is a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted monovalent heterocyclic group having 5 to 50 ring atoms. 2. In the formula (1) of the component (B), R １１ ~R １３ are each independently a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms or a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms. １１ ~R １３ 4. The solid electrolyte composition according to 1 or 2, wherein R ２１ ~R ２６5. The solid electrolyte composition according to any one of 1 to 3, wherein R is each independently a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms. ２１ and R ２２ , R ２３ and R ２４ , and R ２５ and R ２６ 6. The solid electrolyte composition according to any one of 1 to 3, wherein at least one pair of R ３１ ~R ３３ and each independently represent a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms. 7. The solid electrolyte composition according to any one of 1 to 6, which uses a compound represented by formula (1) as component (B) and further contains a compound represented by formula (X1) below: Ｘ１ R Ｘ２ R Ｘ３ P (X1) (In formula (X1), R Ｘ１ ~R Ｘ３ are each independently a hydrogen atom or a substituent RA, and R Ｘ１ ~R Ｘ３at least one of which is a substituent RA.) 8. The solid electrolyte composition according to any one of 1 to 7, wherein the proportion of the component (B) is 0.1 to 20 mass% with respect to the total of the components (A) and (B). 9. The solid electrolyte composition according to any one of 1 to 8, wherein the proportion of each of the components (B) is more than 5 volume% with respect to the entire solid electrolyte composition. 10. The solid electrolyte composition according to any one of 1 to 9, wherein the component (A) further contains a halogen atom. 11. The solid electrolyte composition according to any one of 1 to 10, wherein the component (A) contains one or more elements selected from the group consisting of chlorine (Cl), bromine (Br), and iodine (I). 12. The solid electrolyte composition according to any one of 1 to 11, wherein the component (A) contains chlorine (Cl). 13. The solid electrolyte composition according to any one of 1 to 12, wherein the component (A) contains chlorine (Cl) and bromine (Br). 14. The solid electrolyte composition according to any one of 1 to 13, wherein the component (A) has a crystalline structure. 15. The solid electrolyte composition according to any one of 1 to 14, wherein the component (A) has an argyrodite-type crystal structure. 16. The solid electrolyte composition according to any one of 1 to 14, wherein the component (A) has a thiolisiconregion II-type crystal structure. 17. The solid electrolyte composition according to any one of 1 to 16, comprising (C) a solvent. 18. The solid electrolyte composition according to any one of 1 to 16, which is substantially free of (C) a solvent. 19. The solid electrolyte composition according to any one of 1 to 18, comprising (D) an electrode active material. 20. A solid electrolyte layer or electrode mixture obtained from the solid electrolyte composition according to any one of 1 to 19. 21. A lithium ion battery comprising the solid electrolyte layer or electrode mixture according to 20. 22. A lithium ion battery, wherein at least one of an electrode and a solid electrolyte layer comprises (A) a sulfide solid electrolyte containing lithium, phosphorus, and sulfur, and (B) one or more compounds selected from the compounds represented by the following formulas (1) to (3): R １１ R １２ R １３ PO (1) (NR ２１ R ２２ ) (NR ２３ R ２４ ) (NR ２５ R ２６ ) PO (2) (R３１ O) (R ３２ O) (R ３３ O)PO (3) (In formula (1), R １１ ~R １３ are each independently a hydrogen atom or a substituent RA, and R １１ ~R １３ At least one of R is a substituent group RA. ２１ and R ２２ , R ２３ and R ２４ , and R ２５ and R ２６ At least one pair of R are bonded to each other to form a substituted or unsubstituted saturated or unsaturated ring, or are not bonded to each other. ２１ ~R ２６ are each independently a hydrogen atom or a substituent RA, and R ２１ ~R ２６ At least one of R is a substituent group RA. ３１ ~R ３３ are each independently a hydrogen atom or a substituent RB, and R ３１ ~R ３３ At least one of the substituents RA is a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 50 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted monovalent heterocyclic group having 5 to 50 ring atoms. The substituent RB is a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted monovalent heterocyclic group having 5 to 50 ring atoms.

[0006] According to the present invention, a solid electrolyte composition having excellent dispersibility in a non-polar organic solvent can be provided.

[0007] The solid electrolyte composition of Comparative Example 1 was measured ３１ PNMR spectrum and solid measured for component B1 (TOPO) ３１ PNMR spectrum and solid state measurements of the solid electrolyte composition of Example 3３１ The solid electrolyte composition of Example 3 was measured using a PNMR spectrum. ３１ 1 shows the contact time dependence of each peak in the PNMR spectrum. １ The H NMR spectrum and the solid electrolyte composition of Example 3 were measured. １ 1H NMR spectrum measured for the solid electrolyte composition of Example 3. ６ Li NMR spectrum (single pulse method) and solid ６ 1 is a diagram in which the Li NMR spectrum (CP / MAS method) is arranged vertically.

[0008] The solid electrolyte composition, solid electrolyte layer or electrode composite, and lithium ion battery according to the present invention will be described below. In this specification, "x to y" represents a numerical range of "x or more and y or less." When there are multiple lower limit values, such as "x or more," or multiple upper limit values, such as "y or less," for a single technical matter, any combination of upper and lower limit values ​​can be selected from the upper and lower limit values.

[0009] 1. Solid Electrolyte Composition A solid electrolyte composition according to one embodiment of the present invention comprises the following components (A) and (B): (A) a sulfide solid electrolyte containing lithium, phosphorus, and sulfur; and (B) one or more compounds selected from the compounds represented by the following formulas (1) to (3): R １１ R １２ R １３ PO (1) (NR ２１ R ２２ ) (NR ２３ R ２４ ) (NR ２５ R ２６ ) PO (2) (R ３１ O) (R ３２ O) (R ３３ O)PO (3) (In formula (1), R １１ ~R １３ are each independently a hydrogen atom or a substituent RA, and R １１ ~R １３At least one of R is a substituent group RA. ２１ and R ２２ , R ２３ and R ２４ , and R ２５ and R ２６ At least one pair of R are bonded to each other to form a substituted or unsubstituted saturated or unsaturated ring, or are not bonded to each other. ２１ ~R ２６ are each independently a hydrogen atom or a substituent RA, and R ２１ ~R ２６ At least one of R is a substituent group RA. ３１ ~R ３３ are each independently a hydrogen atom or a substituent RB, and R ３１ ~R ３３ At least one of the substituents RA is a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 50 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted monovalent heterocyclic group having 5 to 50 ring atoms. The substituent RB is a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted monovalent heterocyclic group having 5 to 50 ring atoms.

[0010] The solid electrolyte composition described above, which contains component (B) in addition to the solid electrolyte, exhibits high dispersibility in various organic solvents, particularly in nonpolar solvents such as toluene and xylene, and can maintain this dispersion state for a long period of time. This is expected to improve coating properties during the production of all-solid-state lithium-ion batteries, suppressing solid electrolyte degradation while further enhancing battery performance. While the mechanism of this effect is not entirely clear, it is believed that the modifying action of component (B) having a specific structure modifies the particle surface of the solid electrolyte, improving its affinity with nonpolar organic solvents and achieving a uniform dispersion state of the solid electrolyte. Specifically, the oxygen atom in the P=O moiety of component (B) coordinates to the lithium atom on the surface of component (A), and other moieties of component (B), i.e., specific organic groups bonded to the P atom, are radially arranged from the surface of component (A), thereby increasing the affinity between component (A) and the nonpolar solvent, resulting in the above-mentioned effect. Here, it is essential to use the specific structure defined in formulas (1) to (3) as the other moiety; using other structures, such as an alkoxy group, will not provide high dispersibility. The reason for this is thought to be that the oxygen atoms in the alkoxy group are attracted to the lithium atoms on the surface of component (A), resulting in the alkyl moiety being positioned along the surface of component (A). Even when the other moiety contains an oxygen atom, if the structure is bulky, such as an aryloxy group, the aryl moiety will be positioned so as to protrude from the surface of component (A), and the above-mentioned effect is thought to be exhibited without any problems. Furthermore, when an organic material is added to a solid electrolyte, a decrease in ionic conductivity is unavoidable compared to when the solid electrolyte is used alone. However, by using component (B), it is possible to minimize this decrease in ionic conductivity and maintain high ionic conductivity. This effect is also thought to be due to the action of component (B) having a specific structure.

[0011] Hereinafter, each component of the solid electrolyte composition according to one embodiment of the present invention will be described. (Component (A): Solid Electrolyte) Component (A) is not particularly limited and any solid electrolyte may be used as long as it is a sulfide solid electrolyte containing a specific element. The sulfide solid electrolyte is a solid electrolyte that contains at least sulfur atoms and exhibits ionic conductivity due to the contained metal atoms. In addition to sulfur atoms, it preferably contains lithium atoms and phosphorus atoms, and more preferably contains lithium atoms, phosphorus atoms, and halogen atoms, and has ionic conductivity due to lithium atoms. The sulfide solid electrolyte may be an amorphous sulfide solid electrolyte or a crystalline sulfide solid electrolyte.

[0012] (Amorphous sulfide solid electrolyte) An amorphous sulfide solid electrolyte is one in which the X-ray diffraction pattern is a halo pattern in which no peaks other than those derived from the material are observed in X-ray diffraction measurement, regardless of whether or not there is a peak derived from the solid raw material. The amorphous sulfide solid electrolyte can be used without any particular limitation as long as it contains at least sulfur atoms and exhibits ionic conductivity due to the contained metal atoms. Representative examples include, for example, Li ２ S-P ２ S ５ (Li ３ P.S. ４ a solid electrolyte containing sulfur atoms, lithium atoms, and phosphorus atoms, which is composed of lithium sulfide and phosphorus sulfide, such as Li ２ S-P ２ S ５ - LiI, Li ２ S-P ２ S ５ -LiCl, Li ２ S-P ２ S ５ - LiBr, Li ２ S-P ２ S ５ -LiI-LiBr, etc., solid electrolytes composed of lithium sulfide, phosphorus sulfide, and lithium halide; and solid electrolytes further containing other elements such as oxygen and silicon, for example, Li ２ S-P ２ S ５ -Li ２O-LiI, Li ２ S-SiS ２ -P ２ S ５ In order to obtain higher ionic conductivity, a solid electrolyte such as Li ２ S-P ２ S ５ - LiI, Li ２ S-P ２ S ５ -LiCl, Li ２ S-P ２ S ５ - LiBr, Li ２ S-P ２ S ５ A solid electrolyte composed of lithium sulfide, phosphorus sulfide, and lithium halide, such as LiI-LiBr, is preferred. The types of elements constituting the amorphous sulfide solid electrolyte can be identified, for example, by an ICP emission spectrometer.

[0013] The amorphous sulfide solid electrolyte contains at least Li ２ S-P ２ S ５ When Li ２ S and P ２ S ５ From the viewpoint of obtaining higher ionic conductivity, the molar ratio of Li to Li is preferably 65 to 85:15 to 35, more preferably 70 to 80:20 to 30, and even more preferably 72 to 78:22 to 28. ２ S-P ２ S ５ In the case of -LiI-LiBr, the total content of lithium sulfide and diphosphorus pentasulfide is preferably 60 to 95 mol%, more preferably 65 to 90 mol%, and even more preferably 70 to 85 mol%. The ratio of lithium bromide to the total of lithium bromide and lithium iodide is preferably 1 to 99 mol%, more preferably 20 to 90 mol%, even more preferably 40 to 80 mol%, and particularly preferably 50 to 70 mol%.

[0014] When the amorphous sulfide solid electrolyte contains lithium atoms, sulfur atoms, phosphorus atoms, and halogen atoms, the compounding ratio (molar ratio) of these atoms is preferably 1.0 to 1.8: 1.0 to 2.0: 0.1 to 0.8: 0.01 to 0.6, more preferably 1.1 to 1.7: 1.2 to 1.8: 0.2 to 0.6: 0.05 to 0.5, and even more preferably 1.2 to 1.6: 1.3 to 1.7: 0.25 to 0.5: 0.08 to 0.4. Furthermore, when bromine and iodine are used in combination as halogen atoms, the compounding ratio (molar ratio) of lithium atoms, sulfur atoms, phosphorus atoms, bromine atoms, and iodine atoms is preferably 1.0 to 1.8: 1.0 to 2.0: 0.1 to 0.8: 0.01 to 0.3: 0.01 to 0.3, more preferably 1.1 to 1.7: 1.2 to 1.8: 0.2 to 0.6: 0.02 to 0.25: 0.02 to 0.25, more preferably 1.2 to 1.6: 1.3 to 1.7: 0.25 to 0.5: 0.03 to 0.2: 0.03 to 0.2, and even more preferably 1.35 to 1.45: 1.4 to 1.7: 0.3 to 0.45: 0.04 to 0.18: 0.04 to 0.18. By setting the compounding ratio (molar ratio) of lithium atoms, sulfur atoms, phosphorus atoms, and halogen atoms within the above range, it becomes easier to obtain a solid electrolyte having a thiolicon region II type crystal structure described below and having higher ionic conductivity.

[0015] The shape of the amorphous sulfide solid electrolyte is not particularly limited, but may be, for example, particulate. The average particle diameter (D ５０ ) can be, for example, in the range of 0.01 μm to 500 μm, or 0.1 to 200 μm. ５０ ) is the particle size at which 50% of the total particle size is reached when the particle size distribution is accumulated in order from the smallest particle size when an accumulation curve of particle size distribution is drawn, and the volume distribution is an average particle size that can be measured using, for example, a laser diffraction / scattering particle size distribution measuring device.

[0016] (Crystalline sulfide solid electrolyte) A crystalline sulfide solid electrolyte is a solid electrolyte in which a peak derived from the solid electrolyte is observed in the X-ray diffraction pattern in X-ray diffraction measurement, and is a material that does not matter whether or not a peak derived from a solid raw material is present. That is, the crystalline sulfide solid electrolyte includes a crystalline structure derived from the solid electrolyte, and a part of the crystalline structure may be derived from the solid electrolyte, or the entire crystalline structure may be derived from the solid electrolyte. As long as the crystalline sulfide solid electrolyte has the X-ray diffraction pattern described above, it may also contain an amorphous solid electrolyte in part. The crystalline sulfide solid electrolyte may be, for example, a so-called glass ceramic obtained by heating the amorphous sulfide solid electrolyte above the crystallization temperature, and a sulfide solid electrolyte having the following crystalline structure may be used. Examples of crystalline structures that a crystalline sulfide solid electrolyte containing lithium atoms, sulfur atoms, and phosphorus atoms can have include Li ３ P.S. ４ Crystal structure, Li ４ P ２ S ６ Crystal structure, Li ７ P.S. ６ Crystal structure, Li ７ P ３ S １１ Examples of such structures include a crystal structure having peaks at 2θ=approximately 20.2° and 23.6° (for example, JP 2013-16423 A).

[0017] The crystalline sulfide solid electrolyte containing lithium atoms, sulfur atoms, phosphorus atoms, and halogen atoms may have a crystal structure such as Li ４－ｘ Ge １－ｘ P ｘ S ４ Thio-LISICON Region II crystal structure (Kanno et al., Journal of the Electrochemical Society, 148(7)A742-746(2001)), Li ４－ｘ Ge １－ｘ P ｘ S ４Examples of the thio-lisicon region II crystal structure include those having a crystal structure similar to the thio-lisicon region II type (see Solid State Ionics, 177 (2006), 2721-2725). ４－ｘ Ge １－ｘ P ｘ S ４ Thio-LISICON Region II crystal structure, Li ４－ｘ Ge １－ｘ P ｘ S ４ This indicates that the thio-LISICON region II type has a similar crystal structure.

[0018] In X-ray diffraction measurement using CuKα radiation, Li ３ P.S. ４ Diffraction peaks of the crystal structure appear, for example, at 2θ=17.5°, 18.3°, 26.1°, 27.3°, and 30.0°. ４ P ２ S ６ Diffraction peaks of the crystal structure appear, for example, at 2θ=16.9°, 27.1°, and 32.5°. ７ P.S. ６ Diffraction peaks of the crystal structure appear, for example, at 2θ=15.3°, 25.2°, 29.6°, and 31.0°. ７ P ３ S １１ Diffraction peaks of the crystal structure appear, for example, at 2θ=17.8°, 18.5°, 19.7°, 21.8°, 23.7°, 25.9°, 29.6°, and 30.0°, and Li ４－ｘ Ge １－ｘ P ｘ S ４ The diffraction peaks of the thio-LISICON Region II crystal structure appear, for example, at 2θ=20.1°, 23.9°, and 29.5°, and Li ４－ｘ Ge １－ｘ P ｘ S ４Diffraction peaks of a crystal structure similar to that of thio-LISICON Region II type appear, for example, at 2θ=20.2° and 23.6°. Note that these peak positions may vary within a range of ±0.5°.

[0019] The crystal structure of the crystalline sulfide solid electrolyte also includes an argyrodite-type crystal structure. ７ P.S. ６ Crystal structure; Li ７ P.S. ６ The structural skeleton of the compound has the composition formula Li ７－ｘ P １－ｙ Si ｙ S ６ and Li ７＋ｘ P １－ｙ Si ｙ S ６ (x is -0.6 to 0.6, y is 0.1 to 0.6); Li ７－ｘ－２ｙ P.S. ６－ｘ－ｙ Cl ｘ (0.8≦x≦1.7, 0<y≦−0.25x+0.5); Li ７－ｘ P.S. ６－ｘ Ha ｘ (Ha is Cl or Br, and x is preferably 0.2 to 1.8).

[0020] Among the above crystal structures, the crystal structure of the crystalline sulfide solid electrolyte is Li ３ P.S. ４ The crystal structure, the thiolicon region II crystal structure, and the argyrodite crystal structure are preferred.

[0021] The shape of the crystalline sulfide solid electrolyte is not particularly limited, but may be, for example, particulate. The average particle diameter (D ５０ ) is the average particle size (D ５０ ) and the range of 0.01 μm to 500 μm, or 0.1 to 200 μm, for example, can be exemplified.

[0022] (Component (B): Compounds represented by formulas (1) to (3)) Component (B) is one or more compounds selected from the compounds represented by formulas (1) to (3). One of these may be used alone, or two or more may be used in combination. Component (B) may contain impurities that are generated during the production process and cannot be substantially removed or purified.

[0023] In one embodiment, the molecular weight of component (B) is 1-10,000, 1-5,000, 1-3,000, or 1-1,000.

[0024] Each of the components (B) will be described below. The substituent RA in formulas (1) and (2) is a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 50 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted monovalent heterocyclic group having 5 to 50 ring atoms. When multiple RA are present in one compound, the multiple RA may be the same or different. The substituent RB in formula (3) is a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted monovalent heterocyclic group having 5 to 50 ring atoms. When multiple RB are present in one compound, the multiple RB may be the same or different. In the case of "substituted or unsubstituted", examples of the substituent include an alkyl group having 1 to 50 carbon atoms, an alkenyl group having 2 to 50 carbon atoms, an alkynyl group having 2 to 50 carbon atoms, a cycloalkyl group having 3 to 50 ring carbon atoms, an aryl group having 6 to 50 ring carbon atoms, or a monovalent heterocyclic group having 5 to 50 ring atoms. In one embodiment, the substituent RA is an unsubstituted group. In one embodiment, the substituent RB is an unsubstituted group.

[0025] (Compound represented by formula (1)) R １１ R １２ R １３ PO (1) In formula (1), R １１ ~R １３ are each independently a hydrogen atom or a substituent RA, and R １１ ~R１３ At least one of is a substituent RA.

[0026] In one embodiment, R １１ ~R １３ are each independently a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms. The number of carbon atoms may be, for example, 1 to 30, 1 to 20, or 1 to 15. In one embodiment, R １１ ~R １３ are each independently a substituted or unsubstituted alkyl group having 4 to 20 carbon atoms. １１ ~R １３ The total number of carbon atoms may be 12 to 60, 12 to 50, or 12 to 40.

[0027] In one embodiment, R １１ ~R １３ are each independently a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms. The number of carbon atoms may be, for example, 6 to 20, 6 to 15, or 6 to 10.

[0028] (Compound represented by formula (2)) (NR ２１ R ２２ ) (NR ２３ R ２４ ) (NR ２５ R ２６ )PO (2) In formula (2), R ２１ and R ２２ , R ２３ and R ２４ , and R ２５ and R ２６ At least one pair of R are bonded to each other to form a substituted or unsubstituted saturated or unsaturated ring, or are not bonded to each other. ２１ ~R ２６ are each independently a hydrogen atom or a substituent RA, and R ２１ ~R ２６ At least one of R is a substituent group RA. ２１ and R ２２ When R are bonded to each other to form a substituted or unsubstituted, saturated or unsaturated ring, the ring formed may be, for example, a nitrogen-containing ring structure having 3 to 10 carbon atoms, such as a pyrrolidine skeleton-containing structure.２３ and R ２４ , and R ２５ and R ２６ Also, R ２１ and R ２２ The ring may be formed in the same manner as in

[0029] In one embodiment, R ２１ ~R ２６ are each independently a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms. The number of carbon atoms may be, for example, 1 to 30, 1 to 20, or 1 to 15.

[0030] (Compound represented by formula (3)) (R ３１ O) (R ３２ O) (R ３３ O)PO (3) In formula (3), R ３１ ~R ３３ are each independently a hydrogen atom or a substituent RB, and R ３１ ~R ３３ At least one of is a substituent RB.

[0031] In one embodiment, R ３１ ~R ３３ are each independently a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms. The number of carbon atoms may be, for example, 6 to 20, 6 to 15, or 6 to 10.

[0032] As described above, all of the compounds represented by formulas (1) to (3) contribute significantly to the effects of the present invention. In one embodiment, a compound represented by formula (1) or formula (3) is used as component (B). In this case, in addition to high dispersibility in organic solvents, the effect of maintaining high ionic conductivity is also obtained. In particular, in formula (1), R １１ ~R １３ are each independently a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, and in formula (3), R ３１ ~R ３３ This effect is significant when each of the groups independently represents a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms.

[0033] (Solid Electrolyte Composition) The solid electrolyte composition according to one aspect of the present invention is not particularly limited as long as it contains component (A) and component (B). In one embodiment, the proportion of component (B) (the total amount of components (B) when multiple components (B) are contained) is 0.1 to 20 mass% relative to the total of component (A) and component (B), and may be 1 to 20 mass%, 2 to 15 mass%, or 3 to 10 mass%. In one embodiment, the proportion of each component (B) is greater than 5 vol%, 10 vol% or more, 15 vol% or more, or 20 vol% or more relative to the total solid electrolyte composition.

[0034] In one embodiment, the ionic conductivity of the solid electrolyte composition is 1.40 mS / cm or more, and may be, for example, 1.50 mS / cm or more, 2.00 mS / cm or more, 3.00 mS / cm or more, 4.00 mS / cm or more, or 5.00 mS / cm or more. The ionic conductivity is measured by the method described in the Examples.

[0035] In one embodiment, in addition to the component (B), a compound represented by the following formula (X1) (hereinafter, sometimes referred to as component (Bα)) may be contained. Ｘ１ R Ｘ２ R Ｘ３ P (X1) In formula (X1), R Ｘ１ ~R Ｘ３ are each independently a hydrogen atom or a substituent RA, and R Ｘ１ ~R Ｘ３ At least one of the groups is a substituent RA. The substituent RA is as defined above.

[0036] In one embodiment, R Ｘ１ ~R Ｘ３ are each independently a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms. The number of carbon atoms may be, for example, 1 to 30, 1 to 20, or 1 to 15. In one embodiment, R Ｘ１ ~R Ｘ３ are each independently a substituted or unsubstituted alkyl group having 4 to 20 carbon atoms. １１ ~R １３ The total number of carbon atoms may be 12 to 60, 12 to 50, or 12 to 40.

[0037] In one embodiment, a compound represented by formula (1) is used as component (B), and component (Bα) is further used.

[0038] The mass ratio of component (B) to component (Bα) is, for example, 1:9 to 9:1, or 2:8 to 8:2.

[0039] The solid electrolyte composition according to one embodiment of the present invention may contain, or may be substantially free of, a solvent (C). "Substantially free" means, for example, that the composition contains a trace amount of solvent that cannot be completely removed even by solvent removal. Known solvents can be used.

[0040] The solid electrolyte composition according to one embodiment of the present invention may contain (D) an electrode active material. The electrode active material is as described below.

[0041] In one embodiment, 80% by mass or more, 90% by mass or more, 95% by mass or more, 99% by mass or more, 99.5% by mass or more, 99.9% by mass or more, or 100% by mass of the solid electrolyte composition is components (A) and (B), components (A), (B), and component (Bα), components (A), (B) and (C), components (A), (B), components (Bα) and (C), components (A), (B) and (D), components (A), (B), components (Bα) and (D), components (A), (B), (C) and (D), or components (A), (B), components (Bα), (C) and (D).

[0042] In one embodiment, the proportion of compounds having a molecular weight of 10,000 or less in all components other than component (A) in the solid electrolyte composition is 80% by mass or more, 90% by mass or more, 95% by mass or more, 99% by mass or more, 99.5% by mass or more, 99.9% by mass or more, or 100% by mass.

[0043] In one embodiment, the proportion of the compound having a molecular weight of more than 10,000 in the solid electrolyte composition is 20% by mass or less, 10% by mass or less, 5% by mass or less, 1% by mass or less, 0.5% by mass or less, 0.1% by mass or less, or 0. The molecular weight of the high molecular weight component is the number average molecular weight (Mn) measured by GPC (Gel Permeation Chromatography).

[0044] 2. Solid Electrolyte Layer or Electrode Mixture The solid electrolyte composition according to one embodiment of the present invention can be used for a solid electrolyte layer, a positive electrode, a negative electrode, or the like of a lithium ion secondary battery or the like.

[0045] (Solid Electrolyte Layer) A solid electrolyte layer according to one embodiment of the present invention includes the above-described solid electrolyte composition or is produced from the above-described solid electrolyte composition. The solid electrolyte layer may include only the above-described solid electrolyte composition or may be produced only from the above-described solid electrolyte composition, or may further include a binder. As the binder, the same binder as that described in the negative electrode mixture described below can be used. Other components of the solid electrolyte layer are as described in the solid electrolyte layer of a lithium ion battery described below.

[0046] (Electrode Mixture) An electrode mix according to one embodiment of the present invention contains the above-described solid electrolyte composition and an active material, or is produced from a composition containing the above-described solid electrolyte composition and an active material. When a negative electrode active material is used as the active material, the electrode mix becomes a negative electrode mix, and when a positive electrode active material is used, the electrode mix becomes a positive electrode mix.

[0047] (Negative Electrode Composite) Examples of the negative electrode active material used in the negative electrode composite include carbon materials and metal materials. Composites of two or more of these materials can also be used. Future-developed negative electrode active materials can also be used. Furthermore, it is preferable that the negative electrode active material has electronic conductivity. Examples of carbon materials include graphite (e.g., artificial graphite), graphite carbon fiber, resin-baked carbon, pyrolytic vapor-grown carbon, coke, mesocarbon microbeads (MCMB), furfuryl alcohol resin-baked carbon, polyacene, pitch-based carbon fiber, vapor-grown carbon fiber, natural graphite, and non-graphitizable carbon. Examples of metal materials include elemental metals, alloys, and metal compounds. Examples of such elemental metals include metallic silicon, metallic tin, metallic lithium, metallic indium, and metallic aluminum. Examples of such alloys include alloys containing at least one of silicon, tin, lithium, indium, and aluminum. Examples of such metal compounds include metal oxides. Examples of such metal oxides include silicon oxide, tin oxide, and aluminum oxide.

[0048] In one embodiment, the blending ratio of the negative electrode active material to the solid electrolyte composition is negative electrode active material:solid electrolyte composition (mass ratio)=95:5 to 5:95, 90:10 to 10:90, or 85:15 to 15:85.

[0049] The negative electrode mixture may further contain a conductive additive. When the electronic conductivity of the negative electrode active material is low, it is preferable to add a conductive additive. The conductive additive may have electrical conductivity, and its electronic conductivity is preferably 1×10 ３ S / cm or more, more preferably 1×10 ５ S / cm or more. Specific examples of the conductive additive include carbon materials, nickel, copper, aluminum, indium, silver, cobalt, magnesium, lithium, chromium, gold, ruthenium, platinum, beryllium, iridium, molybdenum, niobium, osmium, rhodium, tungsten, and zinc, and more preferably, carbon material with high conductivity, carbon material other than carbon material, and metal material, mixture, or compound containing nickel, copper, silver, cobalt, magnesium, lithium, ruthenium, gold, platinum, niobium, osmium, or rhodium. Specific examples of the carbon material include carbon black such as ketjen black, acetylene black, denka black, thermal black, and channel black; graphite, carbon fiber, activated carbon, etc., which can be used alone or in combination of two or more. Among these, acetylene black, denka black, and ketjen black, which have high electronic conductivity, are preferred.

[0050] When the negative electrode mixture contains a conductive additive, the content of the conductive additive in the mixture is preferably 1 to 40 mass %, more preferably 2 to 20 mass %.

[0051] A binder may be further included to tightly bind the negative electrode active material and the solid electrolyte composition. Examples of binders include fluorine-containing resins such as polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), and fluorine-containing rubber, thermoplastic resins such as polypropylene and polyethylene, ethylene-propylene-diene rubber (EPDM), sulfonated EPDM, and natural butyl rubber (NBR), which may be used alone or as a mixture of two or more. Also usable are aqueous binders such as cellulose-based binders and aqueous dispersions of styrene-butadiene rubber (SBR).

[0052] The negative electrode composite can be produced by mixing a solid electrolyte composition with a negative electrode active material, or a solid electrolyte composition with a negative electrode active material and an optional conductive additive and / or binder. The mixing method is not particularly limited, but examples include dry mixing, in which the raw materials are mixed using a mortar, ball mill, bead mill, jet mill, planetary ball mill, vibrating ball mill, sand mill, or cutter mill; and wet mixing, in which the raw materials are dispersed in an organic solvent and then mixed using a mortar, ball mill, bead mill, planetary ball mill, vibrating ball mill, sand mill, or Filmix, followed by removal of the solvent. Of these, wet mixing is preferred in order to avoid destroying the negative electrode active material particles.

[0053] (Positive electrode mixture) The positive electrode active material used in the positive electrode mixture is a material capable of inserting and extracting lithium ions, and any positive electrode active material known in the battery field can be used. Positive electrode active materials to be developed in the future can also be used.

[0054] Examples of the positive electrode active material include metal oxides and sulfides. Sulfides include metal sulfides and non-metal sulfides. Metal oxides include, for example, transition metal oxides. Specifically, V ２ O ５ , V ６ O １３ , LiCoO ２ , LiNiO ２ , LiMnO ２ , LiMn ２ O ４ , Li(Ni ａ Co ｂ Mnｃ ) O ２ (Here, 0<a<1, 0<b<1, 0<c<1, a+b+c=1), LiNi １－Ｙ Co Ｙ O ２ , LiCo １－Ｙ Mn Ｙ O ２ , LiNi １－Ｙ Mn Ｙ O ２ (where 0≦Y<1), Li(Ni ａ Co ｂ Mn ｃ ) O ４ (0<a<2, 0<b<2, 0<c<2, a+b+c=2), LiMn ２－Ｚ Ni Ｚ O ４ , LiMn ２－Ｚ Co Ｚ O ４ (where 0<Z<2), LiCoPO ４ , LiFePO ４ , CuO, Li(Ni ａ Co ｂ Al ｃ ) O ２ (where 0<a<1, 0<b<1, 0<c<1, a+b+c=1) and the like. Examples of metal sulfides include titanium sulfide (TiS ２ ), molybdenum sulfide (MoS ２ ), iron sulfide (FeS, FeS ２ ), copper sulfide (CuS) and nickel sulfide (Ni ３ S ２ Other examples of metal oxides include bismuth oxide (Bi ２ O ３ ), bismuth lead oxide (Bi ２ Pb ２ O ５ ) and the like. Examples of non-metal sulfides include organic disulfide compounds, carbon sulfide compounds, and the like. In addition to the above, niobium selenide (NbSe ３ ), metallic indium, and sulfur can also be used as the positive electrode active material.

[0055] The positive electrode composite may further contain a conductive additive. The conductive additive is the same as that described for the negative electrode composite. The blending ratio of the solid electrolyte composition and the positive electrode active material in the positive electrode composite is the same as the blending ratio of the solid electrolyte composition and the negative electrode active material described above. The content of the conductive additive in the positive electrode composite is the same as the content of the conductive additive in the negative electrode composite described above. The manufacturing method for the positive electrode composite is the same as the manufacturing method for the negative electrode composite described above.

[0056] 3. Lithium-ion Battery A lithium-ion battery according to one embodiment of the present invention (first lithium-ion battery) includes one or more selected from the group consisting of the above-described solid electrolyte layer, anode composite, and cathode composite, or includes one or more selected from the group consisting of the above-described solid electrolyte layer, anode layer produced from the above-described anode composite, and cathode layer produced from the above-described cathode composite. Lithium-ion batteries typically have a structure in which the anode layer, electrolyte layer, and cathode layer are stacked in this order.

[0057] (Negative electrode layer) When the negative electrode composite according to one embodiment of the present invention is used as the negative electrode layer, the negative electrode composite is as described above. When a material other than the negative electrode composite according to one embodiment of the present invention is used as the negative electrode layer, a known configuration may be adopted.

[0058] The thickness of the negative electrode layer is, for example, 100 nm to 5 mm, 1 μm to 3 mm, or 5 μm to 1 mm. The negative electrode layer can be produced by a known method, for example, a coating method or an electrostatic method (electrostatic spray method, electrostatic screen method, etc.).

[0059] (Electrolyte Layer) When the solid electrolyte layer according to an embodiment of the present invention is used as the electrolyte layer, the solid electrolyte layer is as described above. When a layer other than the solid electrolyte layer according to an embodiment of the present invention is used as the electrolyte layer, a known configuration may be adopted.

[0060] The thickness of the electrolyte layer is, for example, 0.001 mm or more and 1 mm or less. The solid electrolyte of the electrolyte layer may be fused. "Fusing" means that some of the solid electrolyte particles are dissolved and the dissolved portions are integrated with other solid electrolyte particles. The electrolyte layer may also be a plate-like body of solid electrolyte, and this plate-like body may include a case where some or all of the solid electrolyte particles are dissolved to form a plate-like body. The electrolyte layer can be produced by a known method, for example, a coating method or an electrostatic method (electrostatic spray method, electrostatic screen method, etc.).

[0061] (Positive Electrode Layer) When the positive electrode composite according to one embodiment of the present invention is used as the positive electrode layer, the positive electrode composite is as described above. When a material other than the positive electrode composite according to one embodiment of the present invention is used as the positive electrode layer, a known configuration may be adopted. The thickness of the positive electrode layer is, for example, 0.01 mm or more and 10 mm or less. The positive electrode layer can be manufactured by a known method, for example, a coating method or an electrostatic method (electrostatic spray method, electrostatic screen method, etc.).

[0062] (Current Collector) In one embodiment, the lithium-ion battery includes a current collector. For example, the negative electrode current collector is provided on the side of the negative electrode layer opposite the electrolyte layer, and the positive electrode current collector is provided on the side of the positive electrode layer opposite the electrolyte layer. The current collector may be a plate or foil made of copper, magnesium, stainless steel, titanium, iron, cobalt, nickel, zinc, aluminum, germanium, indium, lithium, or an alloy thereof.

[0063] The lithium ion battery can be manufactured by laminating and bonding the above-mentioned components. Bonding methods include stacking the components and applying pressure or pressure between two rolls (roll to roll). Bonding may be performed via an active material having ion conductivity on the bonding surface or an adhesive material that does not inhibit ion conductivity. Bonding may be performed by heat fusion within a range that does not change the crystal structure of the solid electrolyte. The lithium ion battery can also be manufactured by sequentially forming the above-mentioned components. It can be manufactured by known methods, such as a coating method or an electrostatic method (electrostatic spray method, electrostatic screen method, etc.).

[0064] In a lithium ion battery (second lithium ion battery) according to another embodiment of the present invention, at least one of the electrodes (negative electrode layer and positive electrode layer) and the solid electrolyte layer contains the following components (A) and (B): (A) a sulfide solid electrolyte containing lithium, phosphorus, and sulfur; and (B) one or more compounds selected from the compounds represented by formulas (1) to (3).

[0065] The component (A) and the component (B) are as described in the solid electrolyte composition according to one embodiment of the present invention.

[0066] The second lithium-ion battery is the same as the first lithium-ion battery, except that the provision in the first lithium-ion battery that "includes one or more selected from the group consisting of the above-described solid electrolyte layer, anode composite, and cathode composite, or includes one or more selected from the group consisting of the above-described solid electrolyte layer, anode layer produced from the above-described anode composite, and cathode layer produced from the above-described cathode composite" is rephrased as "at least one of the electrode and the solid electrolyte layer includes the following component (A) and component (B)," and each configuration can be appropriately applied. When each layer of the second lithium-ion battery includes component (A) and component (B), the content ratio of component (A) to component (B) is as described in the solid electrolyte composition according to one embodiment of the present invention.

[0067] The present invention will be described in more detail below with reference to examples. Component (B) used in the following examples and component (B') (a component corresponding to component (B)) used in the comparative examples are as follows. The accompanying alphabetical notations are abbreviations for each compound. B1: Tri-n-octylphosphine oxide (TOPO) B2: Triphenylphosphine oxide (TPPO) B3: Tripyrrolidinophosphine oxide (TpydPO) B4: Tris(diethylamino)phosphine oxide (HMPA) B5: Triphenyl phosphate (PhPho) B'1: Triethyl phosphate (TEPho)

[0068] The evaluation methods used in the examples and comparative examples are as follows.

[0069] (1) Ionic Conductivity Measurement A sample of solid electrolyte or solid electrolyte composition was filled into a tablet press, and a pressure of 400 MPa was applied to form a compact (also called a "pellet," with a diameter of approximately 10 mm and a thickness of approximately 0.1 to 0.2 cm). Carbon was placed on both sides of the compact as electrodes, and pressure was again applied using the tablet press to produce a compact for measurement. The ionic conductivity of this compact for measurement was measured by AC impedance measurement. The conductivity value was measured at 25°C.

[0070] (2) Ion Conductivity Retention Rate The degree of change in ionic conductivity due to the addition of component (B) was measured. Specifically, in Examples 1 to 12 and Comparative Example 2, the rate of change in ionic conductivity was calculated based on the ionic conductivity in Comparative Example 1, which used only the same component (A). In Example 13, the rate of change in ionic conductivity was calculated based on the ionic conductivity in Comparative Example 3, which used only the same component (A).

[0071] (3) Dispersibility (Transmittance Evaluation) The dispersibility of the solid electrolyte composition was evaluated by measuring the transmittance of a pulsed light source with a wavelength of 850 nm using a "TURBISCAN CLASSIC (MA2000)" manufactured by Formulation. Specifically, 0.015 g of the solid electrolyte composition and 6 ml of p-xylene were mixed in a transparent screw tube (8 ml) and stirred for 10 seconds using an ultrasonic device to obtain a mixed solution. The entire mixed solution was transferred to a dedicated glass cell with a cap, and measurements were performed using the MA2000 at 1-minute intervals for 30 minutes to observe changes over time (the height from the bottom of the glass cell to the liquid surface was approximately 6 cm). Because the liquid surface and the vicinity of the bottom are strongly affected by disturbance factors such as adhesion to the glass cell and convection associated with sample sedimentation, it is difficult to evaluate samples with significantly different dispersibility using uniform measurement and analysis conditions. Therefore, a uniform evaluation was performed by using the average transmittance at a position 30 to 35 mm from the bottom of the glass cell 15 minutes after the start of measurement as a value representing the dispersibility of the entire sample. If the dispersibility is high, the pulsed light source is scattered by the solid electrolyte composition, resulting in a decrease in transmittance. If the dispersibility is low, the solid electrolyte composition settles, causing the pulsed light source to pass through the glass cell, resulting in an increase in transmittance. At this time, the transmittance of the internal standard of the device is set to 100%.

[0072] Production Example 1 (Production of Component (A): Argyrodite-Type Solid Electrolyte (Sulfide Solid Electrolyte)) (A) Preparation of Raw Material Mixture In a glove box under a nitrogen atmosphere, each compound was pulverized and mixed in a mixture having a molar ratio of Li ２ S:P ２ S ５ The raw materials were weighed so that the ratio of LiBr:LiCl was 47.5:12.5:15.0:25.0, and the mixture was placed in a glass container and roughly mixed by shaking the container. The roughly mixed raw materials were dispersed in a mixed solvent of dehydrated toluene (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) and dehydrated isobutyronitrile (manufactured by Kishida Chemical Co., Ltd.) under a nitrogen atmosphere to obtain a raw material mixture slurry of approximately 10% by mass. The raw material mixture slurry was mixed and pulverized using a bead mill (LMZ015, manufactured by Ashizawa Finetech Co., Ltd.) while maintaining the nitrogen atmosphere. The treated slurry was placed in a nitrogen-substituted Schlenk flask and then dried under reduced pressure to prepare a raw material mixture.

[0073] (B) Firing Step The raw material mixture obtained in (A) above was heated in an electric furnace (F-1404-A, manufactured by Tokyo Glass Instruments Co., Ltd.) in a glove box under a nitrogen atmosphere. ２ O ３ The raw material mixture was placed in a sagger (999-60S, manufactured by Tokyo Glass Instruments Co., Ltd.) and subjected to heat treatment in an electric furnace at 430°C for 1 hour or more. Thereafter, the sagger was removed from the electric furnace and slowly cooled to obtain an argyrodite-type solid electrolyte.

[0074] (C) Microparticulation Step The obtained argyrodite-type solid electrolyte was dispersed in a mixed solvent of dehydrated toluene (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) and dehydrated isobutyronitrile (manufactured by Kishida Chemical Co., Ltd.) under a nitrogen atmosphere to obtain a solid electrolyte slurry. The slurry was mixed and pulverized using a bead mill (LMZ015, manufactured by Ashizawa Finetech Co., Ltd.) while maintaining the nitrogen atmosphere. The solid electrolyte slurry after the treatment was placed in a nitrogen-substituted Schlenk flask and then dried under reduced pressure to obtain a microparticulated argyrodite-type solid electrolyte (component (A): hereinafter also referred to as "A1").

[0075] As a result of X-ray diffraction (XRD) measurement, peaks attributable to an argyrodite-type crystal structure were observed at 2θ=25.5±1.0 deg and 29.9±1.0 deg in the XRD pattern.

[0076] Production Example 2 (Component (A): Production of a solid electrolyte (sulfide solid electrolyte) having a thiolicon region II crystal structure) In a Schlenk flask (volume: 100 mL) with a stirrer, 0.59 g of lithium sulfide, 0.95 g of diphosphorus pentasulfide, 0.19 g of lithium bromide, and 0.28 g of lithium iodide were introduced under a nitrogen atmosphere. After rotating the stirrer, 20 mL of the complexing agent tetramethylethylenediamine (TMEDA) was added, and stirring was continued for 12 hours. The resulting complex-containing material was dried under vacuum (room temperature: 23 ° C.) to obtain a powdered complex. Next, the complex powder was heated under vacuum at 120 ° C. for 2 hours to obtain an amorphous sulfide solid electrolyte. Furthermore, the amorphous sulfide solid electrolyte was heated under vacuum at 140 ° C. for 2 hours to obtain a crystalline sulfide solid electrolyte A2.

[0077] Example 1 (Preparation and Evaluation of Solid Electrolyte Composition) Under a nitrogen atmosphere, a 50 mL Schlenk flask containing a stirrer tip was charged with 1.5 g of A1 and B1 (TOPO) in an amount such that the amount of B1 relative to the total amount of A1 and B1 was 1% by mass, and 15.5 mL of toluene was added to form a mixture (slurry). While maintaining the nitrogen atmosphere, the mixture was stirred at 60°C for 1 hour. The mixture was then vacuum dried at room temperature until it became an approximately dry powder, and then vacuum dried at 80°C for 1 hour to obtain a powdered solid electrolyte composition. The evaluation results of the obtained solid electrolyte composition are shown in Table 1. The volume ratio (volume %) of B1 relative to the total volume of A1 and B1 is also shown in Table 1 (the same applies to the following Examples and Comparative Examples).

[0078] Examples 2 and 3 Solid electrolyte compositions were produced and evaluated in the same manner as in Example 1, except that A1 and B1 were added in amounts such that the amount of B1 relative to the total amount of A1 and B1 was 3 mass % or 10 mass %. The results are shown in Table 1.

[0079] Examples 4 to 6 Solid electrolyte compositions were produced and evaluated in the same manner as in Example 1, except that B1 (TOPO) was used as component (B) and tri-n-octylphosphine (TOP) was further added. The results are shown in Table 1. The amounts of B1 (TOPO) and TOP were 0.5 mass%, 1.5 mass%, and 5 mass%, respectively, relative to the total amount of A1, B1, and TOP.

[0080] Example 7 A solid electrolyte composition was produced and evaluated in the same manner as in Example 1, except that the amount of B1 was 3 mass% relative to the total amount of A1, B1, and TOP, and the amount of TOP was 7 mass% relative to the total amount of A1, B1, and TOP. The results are shown in Table 1.

[0081] Examples 8 to 12 Solid electrolyte compositions were produced and evaluated in the same manner as in Example 1, except that component (B) shown in Table 1 was used instead of B1, and the amounts of A1 and component (B) relative to the total amount of A1 and component (B) were set as shown in Table 1. The results are shown in Table 1.

[0082] A solid electrolyte composition was produced and evaluated in the same manner as in Example 1, except that A2 was used instead of A1, and A2 and B1 (TOPO) were used in amounts such that the amount of B1 relative to the total amount of A2 and B1 was 9 mass %. The results are shown in Table 1.

[0083] Comparative Example 1 A solid electrolyte composition was produced and evaluated in the same manner as in Example 1, except that component (B) was not used. The results are shown in Table 1.

[0084] Comparative Example 2 A solid electrolyte composition was produced and evaluated in the same manner as in Example 1, except that component (B') shown in Table 1 was used instead of B1, and the amount of component (B') relative to the total amount of A1 and component (B') was set to the amount shown in Table 1. The results are shown in Table 1.

[0085] Comparative Example 3 A solid electrolyte composition was produced and evaluated in the same manner as in Example 13, except that component (B) was not used. The results are shown in Table 1.

[0086]

[0087] (1) In the dispersibility evaluation, the solid electrolyte compositions of Examples 1 to 12 had a transmittance of 0% even 15 minutes after stirring, maintaining a uniformly dispersed state for a long time, confirming extremely high dispersibility. In Comparative Example 1, which did not use component (B), sedimentation of component (A) occurred 15 minutes after stirring, making it difficult to maintain a dispersed state. Furthermore, the dispersibility of Comparative Example 2, which used only component (B') other than component (B), was comparable to that of Comparative Example 1. This is thought to be due to the use of component (B) having a specific structure, which modified the particle surface of component (A) (solid electrolyte), improving the affinity between component (A) and the organic solvent. A comparison between Example 13, which uses A2 as component (A), and Comparative Example 3 also confirmed the relative superiority of dispersibility in Example 13. (2) The solid electrolyte composition of Comparative Example 1 was measured for its dispersion. ３１ PNMR spectrum (single pulse method) and solid measured for component B1 (TOPO) ３１ PNMR spectrum (Cross-Polarization / Magic-Angle Spinning method, hereinafter referred to as "CP / MAS method") and solid state measurements of the solid electrolyte composition of Example 3 ３１The PNMR spectrum (CP / MAS method) is shown in Figure 1. As can be seen from Figure 1, a new peak was confirmed in the vicinity of 65 ppm in Example 3 compared to Comparative Example 1, and this peak was shifted to a lower magnetic field side than the peak obtained when measuring component B1 (TOPO) alone. This suggests that in Example 3, the electronic state around the P atom of B1 (TOPO) was changed by mixing B1 (TOPO) with the solid electrolyte. (3) Solid Electrolyte Measured for the Solid Electrolyte Composition of Example 3 ３１ The contact time dependence of each peak in the PNMR spectrum (CP / MAS method) is shown in Figure 2. The peak of component B1 (TOPO) increases once and then attenuates. This is thought to be due to an increase in intensity caused by magnetization transfer from hydrogen atoms contained in the alkyl group of component B1 (TOPO) to P atoms, followed by attenuation due to the spin-lattice relaxation behavior of 1H in the rotational system. On the other hand, the peak of the solid electrolyte increases in intensity monotonically with increasing contact time. This suggests that the arrangement of each atom is in the order of the alkyl group of component B1 (TOPO), P atoms of component B1 (TOPO), and P atoms of the solid electrolyte. (4) Measurements of component B1 (TOPO) １ The H MAS NMR spectrum and the solid electrolyte composition of Example 3 were measured. １ The H MAS NMR spectrum is shown in Figure 3. It can be seen that the ratio of broad peaks is reduced in the spectrum of Example 3 compared to the spectrum of component B1 (TOPO) alone. This shows that molecular mobility has increased. Although the reason is not entirely clear, it is thought that the degree of freedom of movement between the alkyl groups of component B1 (TOPO) is higher in the state where component B1 (TOPO) is arranged on the surface of the solid electrolyte than in the solid state of component B1 (TOPO) alone, resulting in improved molecular mobility. (5) Solid Electrolyte Measured for the Solid Electrolyte Composition of Example 3 ６ Li NMR spectrum (single pulse method) and solid ６The Li NMR spectrum (CP / MAS method) is shown in Figure 4. In Example 3, a new peak was observed on the high magnetic field side of the Li atoms contained in the solid electrolyte. Considering this together with the peak change of the P atoms described in (2), it is thought that a new structure of P=O...Li (a structure in which oxygen atoms in the P=O site of component (B) are coordinated to lithium atoms on the surface of component (A)) was formed. Considering the results of (2) to (5) comprehensively, as explained at the beginning of this specification, it is thought that a structure was formed in which at least a portion of the sites other than the oxygen atom of P=O in component (B) (i.e., the specific organic group bonded to the P atom) was radially arranged from the surface of component (A). (6) When component (B), which is an organic material, is used, a decrease in ionic conductivity is inevitable compared to when component (A) is used alone. However, it can be seen that in Examples 1 to 13, which used component (B) with a specific structure, this decrease was kept small and high ionic conductivity was maintained. Among these, B1 (TOPO) and B5 (PhPho) exhibited particularly high ionic conductivity maintenance rates, demonstrating that they were able to achieve both improved dispersibility and ionic conductivity maintenance at a high level. On the other hand, in Comparative Example 2, which used triethyl phosphate (TEPho), the ionic conductivity decreased to 1.38 mS / cm, indicating that the decrease in ionic conductivity due to triethyl phosphate (TEPho) was significant.

[0088] Although several embodiments and / or examples of the present invention have been described in detail above, those skilled in the art will readily be able to make numerous modifications to these exemplary embodiments and / or examples without substantially departing from the novel teachings and advantages of the present invention. Accordingly, these numerous modifications are within the scope of the present invention. The contents of all documents cited in this specification and of the applications from which this application claims priority under the Paris Convention are incorporated by reference in their entirety.

Claims

1. (A) A sulfide solid electrolyte containing lithium, phosphorus, and sulfur, (B) A compound comprising one or more compounds selected from the compounds represented by the following formulas (1) to (3) Solid electrolyte composition. R １１ R １２ R １３ PO (1) (NR ２１ R ２２ )(NR ２３ R ２４ )(NR ２５ R ２６ )PO (2) (R ３１ O)(R ３２ O)(R ３３ O)PO (3) (In formula (1), R １１ ~R １３ Each of these is independently a hydrogen atom or a substituent RA, and R １１ ~R １３ At least one of them is substituent RA. In formula (2), R ２１ and R ２２ , R ２３ and R ２４ , and R ２５ and R ２６ At least one pair of these elements may bond to each other to form a substituted or unsubstituted saturated or unsaturated ring, or they may not bond to each other. ２１ ~R ２６ Each of these is independently a hydrogen atom or a substituent RA, and R ２１ ~R ２６ At least one of them is substituent RA. In formula (3), R ３１ ~R ３３ Each is independently a hydrogen atom or a substituent RB, and R ３１ ~R ３３ At least one of them is substituent RB. The substituent RA is a substituted or unsubstituted C1-C50 alkyl group, a substituted or unsubstituted C2-C50 alkenyl group, a substituted or unsubstituted C2-C50 alkynyl group, a substituted or unsubstituted ring-forming C3-C50 cycloalkyl group, a substituted or unsubstituted ring-forming C6-C50 aryl group, or a substituted or unsubstituted monovalent heterocyclic group with 5-50 ring-forming atoms. The substituent RB is a substituted or unsubstituted aryl group having 6 to 50 ring-forming carbon atoms, or a substituted or unsubstituted monovalent heterocyclic group having 5 to 50 ring-forming atoms.

2. In the above formula (1) of component (B), R １１ ~R １３ The solid electrolyte composition according to claim 1, wherein each is independently a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, or a substituted or unsubstituted ring-forming aryl group having 6 to 50 carbon atoms.

3. In the above formula (1) of component (B), R １１ ~R １３ The solid electrolyte composition according to claim 1, wherein each is independently a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms.

4. In the above formula (2) of component (B), R ２１ ~R ２６ The solid electrolyte composition according to claim 1, wherein each is independently a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms.

5. In the above formula (2) of component (B), R ２１ and R ２２ , R ２３ and R ２４ , and R ２５ and R ２６ The solid electrolyte composition according to claim 1, wherein at least one set of the elements are bonded together to form a substituted or unsubstituted saturated or unsaturated ring.

6. In the above formula (3) of component (B), R ３１ ~R ３３ The solid electrolyte composition according to claim 1, wherein each is independently a substituted or unsubstituted ring-forming aryl group having 6 to 50 carbon atoms.

7. The solid electrolyte composition according to claim 1, wherein the compound represented by formula (1) is used as component (B), and further comprises a compound represented by the following formula (X1). R Ｘ１ R Ｘ２ R Ｘ３ P (X1) (In formula (X1), R Ｘ１ ~R Ｘ３ Each of these is independently a hydrogen atom or a substituent RA, and R Ｘ１ ~R Ｘ３ At least one of them is substituent RA.

8. The solid electrolyte composition according to claim 1, wherein the proportion of component (B) is 0.1 to 20% by mass relative to the sum of component (A) and component (B).

9. The solid electrolyte composition according to claim 1, wherein the proportion of each of the components (B) is greater than 5% by volume relative to the entire solid electrolyte composition.

10. The solid electrolyte composition according to claim 1, wherein component (A) further comprises a halogen atom.

11. The solid electrolyte composition according to claim 1, wherein component (A) comprises one or more elements selected from the group consisting of chlorine (Cl), bromine (Br), and iodine (I).

12. The solid electrolyte composition according to claim 1, wherein component (A) contains chlorine (Cl).

13. The solid electrolyte composition according to claim 1, wherein component (A) comprises chlorine (Cl) and bromine (Br).

14. The solid electrolyte composition according to claim 1, wherein component (A) has a crystalline structure.

15. The solid electrolyte composition according to claim 1, wherein component (A) has an argyrodite-type crystalline structure.

16. The solid electrolyte composition according to claim 1, wherein component (A) has a thiolysicon region type II crystal structure.

17. (C) The solid electrolyte composition according to claim 1, comprising a solvent.

18. (C) The solid electrolyte composition according to claim 1, which is substantially free of solvents.

19. (D) The solid electrolyte composition according to claim 1, comprising an electrode active material.

20. A solid electrolyte layer or electrode mixture obtained from the solid electrolyte composition according to any one of claims 1 to 19.

21. A lithium-ion battery comprising a solid electrolyte layer or electrode composite material as described in claim 20.

22. A lithium-ion battery in which at least one of the electrodes and the solid electrolyte layer comprises (A) a sulfide solid electrolyte containing lithium, phosphorus, and sulfur, and (B) one or more compounds selected from the compounds represented by the following formulas (1) to (3). R １１ R １２ R １３ PO (1) (NR ２１ R ２２ )(NR ２３ R ２４ )(NR ２５ R ２６ )PO (2) (R ３１ O)(R ３２ O)(R ３３ O)PO (3) (In formula (1), R １１ ~R １３ Each of these is independently a hydrogen atom or a substituent RA, and R １１ ~R １３ At least one of them is substituent RA. In formula (2), R ２１ and R ２２ , R ２３ and R ２４ , and R ２５ and R ２６ At least one pair of these elements may bond to each other to form a substituted or unsubstituted saturated or unsaturated ring, or they may not bond to each other. ２１ ~R ２６ Each of these is independently a hydrogen atom or a substituent RA, and R ２１ ~R ２６ At least one of them is substituent RA. In formula (3), R ３１ ~R ３３ Each is independently a hydrogen atom or a substituent RB, and R ３１ ~R ３３ At least one of them is substituent RB. The substituent RA is a substituted or unsubstituted C1-C50 alkyl group, a substituted or unsubstituted C2-C50 alkenyl group, a substituted or unsubstituted C2-C50 alkynyl group, a substituted or unsubstituted ring-forming C3-C50 cycloalkyl group, a substituted or unsubstituted ring-forming C6-C50 aryl group, or a substituted or unsubstituted monovalent heterocyclic group with 5-50 ring-forming atoms. The substituent RB is a substituted or unsubstituted aryl group having 6 to 50 ring-forming carbon atoms, or a substituted or unsubstituted monovalent heterocyclic group having 5 to 50 ring-forming atoms.