Solid electrolyte composition, binder particles, sheet for all-solid state secondary battery, electrode sheet for all-solid state secondary battery, all-solid state secondary battery, and methods for manufacturing same

1. A solid electrolyte composition comprising:

an inorganic solid electrolyte having conductivity for ions of metal elements belonging to Group I or II of the periodic table;

binder particles which have an average particle diameter of 10 nm or more and 50,000 nm or less and encompass an ion-conductive substance; and

a dispersion medium,

wherein the binder particles are formed of the ion-conductive substance and a polymer, and the ion-conductive substance is coated with the polymer having a mass ratio of 5% or more and 100% or less of the ion-conductive substance, and

wherein the ion-conductive substance is coated with the polymer having a mass ratio of 30% or more and 100% or less of the ion-conductive substance.

2. The solid electrolyte composition according to claim 1 ,

wherein the ion-conductive substance is an inorganic solid electrolyte or a liquid electrolyte.

3. The solid electrolyte composition according to claim 1 ,

wherein the ion-conductive substance is an inorganic solid electrolyte or a liquid electrolyte including a liquid having a boiling point of 100° C. or higher or an ionic liquid and a Li salt.

4. The solid electrolyte composition according to claim 1 ,

wherein a polymer forming the binder particles is a polyamide, a polyimide, a polyurea, a urethane resin, or an acrylic resin.

5. The solid electrolyte composition according to claim 1 ,

wherein a Clog P value of the dispersion medium is 1 or more.

6. The solid electrolyte composition according to claim 1 ,

wherein a polymer forming the binder particles has a repeating unit derived from a monomer having an SP value of 11 (cal 1/2 cm −3/2 ) or more or a partial structure derived from a condensation component having an SP value of 11 (cal 1/2 cm −3/2 ) or more.

7. The solid electrolyte composition according to claim 6 ,

wherein a content of the repeating unit or the partial structure in the polymer is 10% by mass or more.

8. The solid electrolyte composition according to claim 1 ,

wherein a mass ratio between the ion-conductive substance and a polymer forming the binder particles is 1:1 to 10.

9. The solid electrolyte composition according to claim 1 ,

wherein the dispersion medium is selected from an ether compound solvent, an aromatic compound solvent, and an aliphatic compound solvent.

10. The solid electrolyte composition according to claim 1 ,

wherein the inorganic solid electrolyte is represented by Formula (1),

L a1 M b1 P c1 S d1 A e1   (1)

in the formula, L represents an element selected from Li, Na, and K, M represents an element selected from B, Zn, Sn, Si, Cu, Ga, Sb, Al, and Ge, A represents I, Br, Cl, or F, a1 to e1 represent the compositional ratios among the respective elements, and a1:b1:c1:d1:e1 satisfies 1 to 12:0 to 5:1:2 to 12:0 to 10.

11. The solid electrolyte composition according to claim 1 , further comprising:

an active material capable of intercalating and deintercalating ions of metal elements belonging to Group I or Group II of the periodic table.

12. A method for manufacturing the solid electrolyte composition according to claim 1 , comprising:

a step of mixing the inorganic solid electrolyte and the binder particles.

13. A sheet for an all-solid state secondary battery, comprising:

a film of the solid electrolyte composition according to claim 1 formed on a base material.

14. A sheet for an all-solid state secondary battery, comprising:

a film of the solid electrolyte composition according to claim 11 formed on a metal foil.

15. A method for manufacturing an electrode sheet for an all-solid state secondary battery, comprising:

a step of forming a film of the solid electrolyte composition according to claim 11 on a metal foil.

16. The method for manufacturing an electrode sheet for an all-solid state secondary battery according to claim 15 , further comprising:

a step of encompassing an ion-conductive substance in a polymer forming binder particles so as to prepare the binder particles, and then, mixing an active material, an inorganic solid electrolyte, the binder particles, and a dispersion medium to prepare a solid electrolyte composition.

17. A method for manufacturing the sheet for an all-solid state secondary battery according to claim 13 , comprising:

a step of mixing an inorganic solid electrolyte, binder particles, and a dispersion medium to prepare a solid electrolyte composition.

18. A method for manufacturing an all-solid state secondary battery, comprising:

manufacturing an all-solid state secondary battery using the method for manufacturing an electrode sheet for an all-solid state secondary battery according to claim 15 .

19. A method for manufacturing an all-solid state secondary battery, comprising:

manufacturing an all-solid state secondary battery using the method for manufacturing the sheet for an all-solid state secondary battery according to claim 17 .

20. The solid electrolyte composition according to claim 8 ,

wherein the mass ratio between the ion-conductive substance and the polymer forming the binder particles is 1:1.5 to 8.

21. A solid electrolyte composition comprising:

an inorganic solid electrolyte having conductivity for ions of metal elements belonging to Group I or II of the periodic table;

binder particles which have an average particle diameter of 10 nm or more and 50,000 nm or less and encompass an ion-conductive substance; and

a dispersion medium,

wherein the binder particles are formed of the ion-conductive substance and a polymer, and the ion-conductive substance is coated with the polymer having a mass ratio of 5% or more and 100% or less of the ion-conductive substance, and

wherein the mass ratio between the ion-conductive substance and the polymer forming the binder particles is 1:1.5 to 8.