Inorganic solid electrolyte-containing composition, sheet for all-solid state secondary battery, and all-solid state secondary battery, and manufacturing methods for sheet for all-solid state secondary battery and all-solid state secondary battery
There is provided an inorganic solid electrolyte-containing composition containing an inorganic solid electrolyte, a polymer binder, and a dispersion medium, in which the polymer binder includes a polymer binder consisting of a fluorine-based copolymer which contains a vinylidene fluoride constitutional component and a hexafluoropropylene constitutional component of 21% to 65% by mole and in which a tensile fracture strain is 500% or more, and the adsorption rate of this polymer binder with respect to the inorganic solid electrolyte is less than 60%. There are also provided a sheet for an all-solid state secondary battery and an all-solid state secondary battery, in which this inorganic solid electrolyte-containing composition is used, and manufacturing methods for a sheet for an all-solid state secondary battery, and an all-solid state secondary battery.
1 . An inorganic solid electrolyte-containing composition comprising:
an inorganic solid electrolyte having an ion conductivity of a metal belonging to Group 1 or Group 2 in the periodic table;
a polymer binder; and
a dispersion medium,
wherein the polymer binder includes a polymer binder consisting of a fluorine-based copolymer which contains a vinylidene fluoride constitutional component and a hexafluoropropylene constitutional component of more than 30% by mole and 65% by mole or less and in which a tensile fracture strain is 500% or more, and
in the dispersion medium, an adsorption rate of the polymer binder consisting of the fluorine-based copolymer with respect to the inorganic solid electrolyte is less than 60%.
2 . The inorganic solid electrolyte-containing composition according to claim 1 ,
wherein the polymer binder consisting of the fluorine-based copolymer is dissolved in the dispersion medium.
3 . The inorganic solid electrolyte-containing composition according to claim 1 ,
wherein a content of the hexafluoropropylene constitutional component in the fluorine-based copolymer is more than 30% by mole and 50% by mole or less.
4 . The inorganic solid electrolyte-containing composition according to claim 1 ,
wherein the tensile fracture strain is 700% or more.
5 . The inorganic solid electrolyte-containing composition according to claim 1 ,
wherein a peel strength of the polymer binder consisting of the fluorine-based copolymer with respect to aluminum foil is 0.1 N/mm or more.
6 . The inorganic solid electrolyte-containing composition according to claim 1 ,
wherein a mass average molecular weight of the fluorine-based copolymer is 50,000 to 1,500,000.
7 . The inorganic solid electrolyte-containing composition according to claim 1 ,
wherein the fluorine-based copolymer contains a constitutional component having a functional group selected from the following Group (a) of functional groups,
<Group (a) of functional groups>
a hydroxy group, an amino group, a carboxy group, a sulfo group, a phosphate group, a phosphonate group, a sulfanyl group, an ether bond, an imino group, an ester bond, an amide bond, a urethane bond, a urea bond, a heterocyclic group, an aryl group, an anhydrous carboxylic acid group, an isocyanate group, an alkoxysilyl group, a fluoroalkyl group, and a siloxane group.
8 . The inorganic solid electrolyte-containing composition according to claim 7 ,
wherein in the fluorine-based copolymer, a content of the constitutional component having the functional group selected from the Group (a) of functional groups is 0.01% to 10% by mole.
9 . The inorganic solid electrolyte-containing composition according to claim 1 ,
wherein the polymer binder includes a particulate binder having an average particle diameter of 1 to 1,000 nm.
10 . The inorganic solid electrolyte-containing composition according to claim 1 ,
wherein the polymer binder includes a binder consisting of a hydrocarbon-based polymer, a binder consisting of a (meth)acrylic polymer, or a polymer binder consisting of a vinyl polymer.
11 . The inorganic solid electrolyte-containing composition according to claim 1 , further comprising an active material.
12 . The inorganic solid electrolyte-containing composition according to claim 11 ,
wherein an adsorption rate of the polymer binder consisting of the fluorine-based copolymer with respect to the active material is 90% or less.
13 . The inorganic solid electrolyte-containing composition according to claim 1 , further comprising a conductive auxiliary agent.
14 . The inorganic solid electrolyte-containing composition according to claim 1 ,
wherein the inorganic solid electrolyte is a sulfide-based inorganic solid electrolyte.
15 . A sheet for an all-solid state secondary battery, comprising a layer formed of the inorganic solid electrolyte-containing composition according to claim 1 .
16 . An all-solid state secondary battery comprising, in the following order:
a positive electrode active material layer;
a solid electrolyte layer; and
a negative electrode active material layer,
wherein at least one of the positive electrode active material layer, the solid electrolyte layer, or the negative electrode active material layer is a layer formed of the inorganic solid electrolyte-containing composition according to claim 1 .
17 . A manufacturing method for a sheet for an all-solid state secondary battery, the manufacturing method comprising forming a film of the inorganic solid electrolyte-containing composition according to claim 1 .
18 . A manufacturing method for an all-solid state secondary battery, the manufacturing method comprising manufacturing an all-solid state secondary battery through the manufacturing method according to claim 17 .
19 . The inorganic solid electrolyte-containing composition according to claim 1 ,
wherein the polymer binder consisting of the fluorine-based copolymer is dissolved in the dispersion medium, and
the fluorine-based copolymer contains a constitutional component having a functional group selected from the following Group (a) of functional groups,
<Group (a) of functional groups>
a hydroxy group, an amino group, a carboxy group, a sulfo group, a phosphate group, a phosphonate group, a sulfanyl group, an ether bond, an imino group, an ester bond, an amide bond, a urethane bond, a urea bond, a heterocyclic group, an aryl group, an anhydrous carboxylic acid group, an isocyanate group, an alkoxysilyl group, a fluoroalkyl group, and a siloxane group.
20 . The inorganic solid electrolyte-containing composition according to claim 1 ,
wherein the polymer binder consisting of the fluorine-based copolymer is dissolved in the dispersion medium,
the fluorine-based copolymer contains a constitutional component having a functional group selected from the following Group (a) of functional groups, and
in the fluorine-based copolymer, a content of the constitutional component having the functional group selected from the Group (a) of functional groups is 0.01% to 10% by mole,
<Group (a) of functional groups>
a hydroxy group, an amino group, a carboxy group, a sulfo group, a phosphate group, a phosphonate group, a sulfanyl group, an ether bond, an imino group, an ester bond, an amide bond, a urethane bond, a urea bond, a heterocyclic group, an aryl group, an anhydrous carboxylic acid group, an isocyanate group, an alkoxysilyl group, a fluoroalkyl group, and a siloxane group.
21 . The inorganic solid electrolyte-containing composition according to claim 1 ,
wherein the polymer binder consisting of the fluorine-based copolymer is dissolved in the dispersion medium, and
a content of the hexafluoropropylene constitutional component in the fluorine-based copolymer is more than 30% by mole and 50% by mole or less.
22 . The inorganic solid electrolyte-containing composition according to claim 1 ,
wherein a content of the hexafluoropropylene constitutional component in the fluorine-based copolymer is more than 30% by mole and 50% by mole or less, and
a peel strength of the polymer binder consisting of the fluorine-based copolymer with respect to aluminum foil is 0.1 N/mm or more.