# US 2024/0194880 A1 · Binder for solid electrolyte-based all solid-state lithium secondary battery, cathode in all solid-state lithium secondary battery comprising the same, separator in all solid-state lithium secondary battery comprising the same, solid electrolyte-based all solid-state lithium secondary battery comprising the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2024/0194880 A1 - Document ID: US20240194880A1 - Status: Published application - Kind: A1 - Application number: 18/554,630 - Filed: 2022-04-04 - Published: 2024-06-13 - Earliest claimed: 2021-04-09 - Assignees: Seoul National University R&Db Foundation - Applicants: Seoul National University R&DB Foundation - Inventors: Jang Wook CHOI; Taegeun LEE - Web page: https://patentgrep.com/patent/US20240194880A1 ## CPC - H01M 4/622: {being polymers} - H01M 10/052: Li-accumulators - H01M 50/414: Synthetic resins, e.g. thermoplastics or thermosetting resins - H01M 10/0525: Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries - H01M 10/0562: Solid materials - H01M 2300/0068: inorganic - Y02E 60/10: Energy storage using batteries - H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract The present disclosure relates to a binder for an all-solid-state lithium secondary battery wherein the carboxyl group of mercaptocarboxylic acid is grafted in a butadiene polymer, wherein a molar ratio of the carboxyl group to the butadiene polymer is 0.1-30:100, a binder for an all-solid-state lithium secondary battery containing the same, an all-solid-state lithium secondary battery electrode composite containing the same, a separator in an all-solid-state lithium secondary battery containing the same, and an all-solid-state lithium secondary battery containing the same. Since the binder for an all-solid-state lithium secondary battery of the present disclosure can satisfy stability, solubility, polarity and adhesive property at the same time, it can significantly accelerate the commercialization of an all-solid-state battery based on a wet process. ## Claims ### Claim 1 A binder for an all-solid-state lithium secondary battery wherein a chain comprising a polar functional group is grafted in a diene-based polymer, wherein the diene-based polymer is a butadiene polymer or an isoprene polymer, the polar functional group have strong attraction to an electrode or a solid electrolyte based on the dipole moment, and a molar ratio of a polar functional group to the monomers in the diene-based polymer is between 0.1-30:100. ### Claim 2 (depends on 1) The binder for an all-solid-state lithium secondary battery according to claim 1, wherein the polar functional group may be any one selected from a group consisting of a carboxyl group, a hydroxyl group, an ester group, an amine group and salts thereof. ### Claim 3 (depends on 1) The binder for an all-solid-state lithium secondary battery according to claim 1, wherein the binder comprises a polymer wherein one or more compound selected from a group consisting of mercapto, hydrogen peroxide, peroxy acid, ozone, halogen, silane and sulfonylhydrazine is grafted to a diene-based polymer. ### Claim 4 (depends on 3) The binder for an all-solid-state lithium secondary battery according to claim 3, wherein the binder is one wherein the polar functional group of a mercapto compound is grafted in the diene-based polymer. ### Claim 5 (depends on 4) The binder for an all-solid-state lithium secondary battery according to claim 4, wherein the mercapto compound is grafted in the diene-based polymer via a thiol group. ### Claim 6 (depends on 1) The binder for an all-solid-state lithium secondary battery according to claim 1, wherein the binder is one wherein the polar functional group of a carboxylic acid compound is grafted in the diene-based polymer. ### Claim 7 (depends on 6) The binder for an all-solid-state lithium secondary battery according to claim 6, wherein the carboxylic acid compound is grafted in the diene-based polymer via an ester group. ### Claim 8 (depends on 7) The binder for an all-solid-state lithium secondary battery according to claim 7, wherein a hydroxyl group is bound to carbon adjacent to the carbon of the diene-based polymer in which the carboxylic acid compound is grafted. ### Claim 9 (depends on 1) The binder for an all-solid-state lithium secondary battery according to claim 1, wherein the polar functional group of the binder forms a hydrogen bond with an OH group present on the surface of a current collector and an active material. ### Claim 10 (depends on 1) The binder for an all-solid-state lithium secondary battery according to claim 1, wherein the binder is soluble in one or more organic solvent selected from a group consisting of n-hexane, toluene, p-xylene, butyl butyrate, tetrahydrofuran and diethyl carbonate. ### Claim 11 (depends on 1) An all-solid-state lithium secondary battery electrode composite comprising the binder according to claim 1, a current collector, an electrode material and a sulfide-based solid electrolyte. ### Claim 12 (depends on 11) The all-solid-state lithium secondary battery electrode composite according to claim 11, wherein the polar functional group of the binder forms a hydrogen bond with an OH group present on the surface of the current collector and the active material. ### Claim 13 (depends on 1) A separator in an all-solid-state lithium secondary battery comprising the binder according to claim 1. ### Claim 14 (depends on 12, 13) An all-solid-state lithium secondary battery comprising the electrode composite according to claim 12 or the separator according to claim 13.