BINDER COMPOSITION FOR ALL-SOLID-STATE SECONDARY BATTERIES, SLURRY FOR ALL-SOLID-STATE SECONDARY BATTERIES, SOLID ELECTROLYTE SHEET FOR ALL-SOLID-STATE SECONDARY BATTERIES, METHOD FOR PRODUCING SAID SOLID ELECTROLYTE SHEET FOR ALL-SOLID-STATE SECONDARY BATTERIES, ALL-SOLID-STATE SECONDARY BATTERY, AND METHOD FOR PRODUCING SAID ALL-SOLID-STATE SECONDARY BATTERY

1 . A binder composition suitable for an all-solid-state secondary battery, the composition comprising:

a polymer (A) comprising an aromatic vinyl unit based on an aromatic vinyl compound and a conjugated diene unit based on a conjugated diene compound;

an anti-aging agent (B) at 200 ppm or more and 5,000 ppm or less with respect to a total binder composition mass; and

a liquid medium (C).

2 . The composition of claim 1 , wherein the anti-aging agent (B) comprises a phenol-based anti-aging agent and/or an amine-based anti-aging agent.

3 . The composition of claim 1 , wherein the polymer (A) has a value α, represented by equation (i):

α=( p +(0.5× r ))/( p+q +(0.5× r )+ s )  (i),

of less than 0.9,

wherein p, q, r, and s are constituent ratios (molar ratios) of a structural unit of formula (1):

a structural unit of formula (2)

a structural unit formula (3)

and

a structural unit formula (4)

—CH 2 —CH═CH—CH 2 —  (4),

in the polymer.

4 . The composition of claim 1 , wherein the polymer (A) has a bound styrene content in a range of from 5% to 40%.

5 . The composition of claim 1 , wherein the polymer (A) has a unit based on a modifier comprising a nitrogen atom, an oxygen atom, a silicon atom, a germanium atom, and/or a tin atom.

6 . The composition of claim 1 , wherein the liquid medium (C) comprising an aliphatic hydrocarbon, an alicyclic hydrocarbon, an aromatic hydrocarbon, ketone, ester, and/or ether.

7 . The composition of claim 1 , wherein the polymer (A) is dissolved in the liquid medium (C).

8 . A slurry suitable for an all-solid-state secondary battery, the slurry comprising:

the binder composition of claim 1 ; and

a solid electrolyte.

9 . The slurry of claim 8 , comprising, as the solid electrolyte, a sulfide-based solid electrolyte or an oxide-based solid electrolyte.

10 . An all-solid-state secondary battery, comprising:

a positive electrode active material layer;

a solid electrolyte layer; and

a negative electrode active material layer,

wherein the positive electrode active material layer, the solid electrolyte layer, and/or the negative electrode active material layer is a layer formed by applying and drying the slurry of claim 8 .

11 . A solid electrolyte sheet suitable for an all-solid-state secondary battery, the sheet comprising:

a substrate; and

a layer formed on the substrate by applying and drying the slurry of claim 8 .

12 . A method of producing a solid electrolyte sheet suitable for an all-solid-state secondary battery, the method comprising:

applying the slurry of claim 8 onto a substrate; and

drying the slurry.

13 . A method of producing an all-solid-state secondary battery, the method comprising:

conducting the method of claim 12 ; and

further processing and thereby producing an all-solid-state secondary battery.

14 . The composition of claim 1 , wherein the anti-aging agent (B) is at least one selected from the group consisting of a phenol-based anti-aging agent and an amine-based anti-aging agent.

15 . The composition of claim 1 , wherein the liquid medium (C) is at least one selected from the group consisting of an aliphatic hydrocarbon, an alicyclic hydrocarbon, an aromatic hydrocarbon, ketone, ester, and ether.