BINDER FOR ALL-SOLID SECONDARY BATTERY, BINDER COMPOSITION FOR ALL-SOLID SECONDARY BATTERY, SLURRY FOR ALL-SOLID SECONDARY BATTERY, SOLID ELECTROLYTE SHEET FOR ALL-SOLID SECONDARY BATTERY AND PRODUCTION METHOD THEREOF, AND ALL-SOLID SECONDARY BATTERY AND PRODUCTION METHOD THEREOF
A binder for an all-solid-state secondary battery, including a polymer (A) that has an aromatic vinyl unit including an aromatic vinyl compound and a conjugated diene unit including a conjugated diene compound. The binder has a Mooney viscosity (ML 1+4 , 100° C.) from 10 to 100 and has a value α, which is represented by the following equation (i), of less than 0.7, where “p”, “q”, “r”, and “s” represent constituent ratios (molar ratios) of a structural unit represented by the following formula (1), a structural unit represented by the following formula (2), a structural unit represented by the following formula (3), and a structural unit represented by the following formula (4) in the polymer, respectively. α=(p+(0.5×r))/(p+q+(0.5×r)+s) • • • (i)
1 . A binder for an all-solid-state secondary battery, comprising a polymer (A) that:
has an aromatic vinyl unit comprising an aromatic vinyl compound and a conjugated diene unit comprising a conjugated diene compound;
has a Mooney viscosity (ML 1+4 , 100° C.) of 10 to 100; and
has a value α, which is represented by the following equation (i), of less than 0.7, where “p”, “q”, “r”, and “s” represent constituent ratios (molar ratios) of a structural unit represented by the following formula (1), a structural unit represented by the following formula (2), a structural unit represented by the following formula (3), and a structural unit represented by the following formula (4) in the polymer, respectively.
α
=
p +
0.5
×
r
/
p+q+
0.5
×
r
+
s
.
2 . The binder for an all-solid-state secondary battery according to claim 1 , wherein the polymer (A) has a bound styrene content of 5% to 40%.
3 . The binder for an all-solid-state secondary battery according to claim 1 , wherein the polymer (A) has a unit comprising a modifier containing at least one kind of atom selected from the group consisting of: a nitrogen atom; an oxygen atom; a silicon atom; a germanium atom; and a tin atom.
4 . A binder composition for an all-solid-state secondary battery, comprising:
the binder for an all-solid-state secondary battery of claim 1 ; and
a liquid medium (B).
5 . The binder composition for an all-solid-state secondary battery according to claim 4 , wherein the liquid medium (B) is at least one selected from the group consisting of: an aliphatic hydrocarbon; an alicyclic hydrocarbon; an aromatic hydrocarbon; ketones; esters; and ethers.
6 . The binder composition for an all-solid-state secondary battery according to claim 4 , wherein the polymer (A) is dissolved in the liquid medium (B).
7 . A slurry for an all-solid-state secondary battery, comprising:
the binder composition for an all-solid-state secondary battery of claim 4 ; and
a solid electrolyte.
8 . The slurry for an all-solid-state secondary battery according to claim 7 , wherein the slurry for an all-solid-state secondary battery comprises, as the solid electrolyte, a sulfide-based solid electrolyte or an oxide-based solid electrolyte.
9 . An all-solid-state secondary battery, comprising at
a positive electrode active material layer;
a solid electrolyte layer; and
a negative electrode active material layer,
wherein at least any one of the positive electrode active material layer, the solid electrolyte layer, and the negative electrode active material layer is a layer formed by applying and drying the slurry for an all-solid-state secondary battery of claim 7 .
10 . A solid electrolyte sheet for an all-solid-state secondary battery, comprising:
a substrate; and
a layer formed on the substrate by applying and drying the slurry for an all-solid-state secondary battery of claim 7 .
11 . A method of producing a solid electrolyte sheet for an all-solid-state secondary battery, comprising applying the slurry for an all-solid-state secondary battery of claim 7 onto a substrate and drying the slurry.
12 . A method of producing an all-solid-state secondary battery, comprising producing an all-solid-state secondary battery via the method of producing a solid electrolyte sheet for an all-solid-state secondary battery of claim 11 .