Negative electrode composition, negative electrode sheet for all-solid state secondary battery, all-solid state secondary battery, method for manufacturing negative electrode sheet for all-solid state secondary battery, and method for manufacturing all-solid state secondary battery

1. A negative electrode active material layer formed of a negative electrode composition, wherein the negative electrode composition comprises:

a sulfide-based inorganic solid electrolyte;

a negative electrode active material containing a silicon atom or a tin atom; and

a polymer,

wherein the polymer has substantially no adsorption capacity to the negative electrode active material and the sulfide-based inorganic solid electrolyte, and a modulus of elasticity of the polymer measured in accordance with JIS K 7161 (2014) is 100 MPa or higher and 1000 MPa or lower, and

the polymer is contained in the negative electrode active material layer in a particle form,

and wherein a content of the polymer in a total solid component is 5% to 20% by mass.

2. The negative electrode active material layer according to claim 1 , wherein in the polymer, a carbon atom content of an ester bond, an amide bond, a carboxyl group, a carbonyl group, a urethane bond, and an imide bond in a total carbon atom content of the polymer is 10% by mol or less.

3. The negative electrode active material layer according to claim 1 , further comprising an electron conductive carbon material in the negative electrode composition.

4. The negative electrode active material layer according to claim 3 , wherein the electron conductive carbon material has an aspect ratio of 3 or more.

5. The negative electrode active material layer according to claim 1 , wherein the negative electrode active material contains a silicon atom.

6. The negative electrode active material layer according to claim 5 , wherein a content of silicon atom in all atoms constituting the negative electrode active material is 50% by mol or more.

7. A negative electrode sheet for an all-solid state secondary battery, comprising the negative electrode active material layer according to claim 1 .

8. An all-solid state secondary battery comprising, in the following order:

a positive electrode active material layer;

a solid electrolyte layer; and

the negative electrode active material layer according to claim 1 .

9. A method for manufacturing a negative electrode sheet for an all-solid state secondary battery using the negative electrode active material layer according to claim 1 , comprising:

performing a coating with the negative electrode composition.

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

obtaining a negative electrode sheet for an all-solid state secondary battery by the manufacturing method according to claim 9 ; and

manufacturing an all-solid state secondary battery using the negative electrode sheet for an all-solid state secondary battery.

11. The negative electrode active material layer according to claim 1 , wherein an aspect ratio of the polymer is 1 to 100.

12. The negative electrode active material layer according to claim 1 , wherein an average particle size of the polymer is in a range of 1000 nm to 2000 nm.

13. The negative electrode active material layer according to claim 1 , wherein an aspect ratio of the polymer is 1 to 100, and an average particle size of the polymer is in a range of 1000 nm to 2000 nm.