# US 10,873,072 B2 · Electrode for lithium-ion secondary battery and manufacturing method thereof, and lithium-ion secondary battery > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,873,072 B2 - Document ID: US10873072B2 - Status: Granted - Kind: B2 - Application number: 15/965,189 - Filed: 2018-04-27 - Published: 2018-08-30 - Granted: 2020-12-22 - Earliest claimed: 2013-08-09 - Assignees: Semiconductor Energy Laboratory Co., Ltd. - Applicants: Semiconductor Energy Laboratory Co., Ltd. - Inventors: Kiyofumi Ogino - Web page: https://patentgrep.com/patent/US10873072B2 ## CPC - H01M 4/134: Electrodes based on metals, Si or alloys - H01M 4/0404: {by coating on electrode collectors} - H01M 4/1395: of electrodes based on metals, Si or alloys - H01M 4/386: {Silicon or alloys based on silicon} - H01M 4/622: {being polymers} - H01M 4/625: {Carbon or graphite} - H01M 4/661: {Metal or alloys, e.g. alloy coatings (H01M4/669 take precedence)} - H01M 4/667: {in the form of layers, e.g. coatings} - H01M 10/0525: Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries - Y02E 60/10: Energy storage using batteries - Y02P 70/50: Manufacturing or production processes characterised by the final manufactured product - Y02T 10/70: Energy storage systems for electromobility, e.g. 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 - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract A highly reliable electrode for a lithium-ion secondary battery is provided. A highly reliable lithium-ion secondary battery is also provided using the electrode for a lithium-ion secondary battery. The electrode for a lithium-ion secondary battery includes a current collector and an active material layer. The active material layer includes an active material, graphene, and polyimide. The active material includes a plurality of nanowires each of which grows with a silicon particle used as a nucleus and extends in one direction into a fine needle. The graphene includes a region in contact with the plurality of nanowires, and polyimide includes a region in contact with the graphene. The lithium-ion secondary battery uses the electrode as a negative electrode. ## Claims ### Claim 1 A method for manufacturing an electrode, comprising the steps of: forming an active material layer comprising silicon particles and a binder; and making a silicon wire from a first part of the silicon particles by heating after forming the active material layer, wherein the silicon particles have an average diameter of 10 nm to 1 μm before the heating, wherein the binder is polyimide, wherein a precursor of polyimide is used for forming the active material layer, and wherein the precursor of polyimide is imidized by the heating. ### Claim 2 (depends on 1) The method for manufacturing the electrode according to claim 1, wherein the silicon wire has a length of ten micrometers or more. ### Claim 3 (depends on 1) The method for manufacturing the electrode according to claim 1, wherein a second part of the silicon particles forms a first aggregated object by the heating. ### Claim 4 (depends on 3) The method for manufacturing the electrode according to claim 3, wherein the silicon wire grows with the first aggregated object as a nucleus. ### Claim 5 (depends on 4) The method for manufacturing the electrode according to claim 4, wherein a third part of the silicon particles forms a second aggregated object by the heating, and wherein the silicon wire is attached to the second aggregated object after the heating. ### Claim 6 (depends on 1) The method for manufacturing the electrode according to claim 1, wherein the heating is performed at a temperature equal to or less than 400° C. ### Claim 7 (depends on 1) The method for manufacturing the electrode according to claim 1, wherein the heating is performed at a temperature equal to or greater than 360° C. and equal to or less than 400° C. ### Claim 8 (depends on 1) The method for manufacturing the electrode according to claim 1, wherein the active material layer comprises a conductive additive. ### Claim 9 (depends on 1) The method for manufacturing the electrode according to claim 1, wherein the active material layer comprises graphene oxide before the heating, wherein the active material layer comprises graphene after the heating. ### Claim 10 (depends on 9) The method for manufacturing the electrode according to claim 9, wherein the active material layer is formed using a slurry comprising the silicon particles, graphene oxide and the precursor of the binder. ### Claim 11 (depends on 10) The method for manufacturing the electrode according to claim 10, wherein the slurry further comprising water is used for forming the active material layer. ### Claim 12 A method for manufacturing an electrode, comprising the steps of: mixing a first mixture comprising silicon particles and graphene oxide, a polyimide precursor and a solvent to form a slurry; and applying the slurry to obtain an applied mixture; and heating the applied mixture, wherein the heating forms a nanowire using a first part of the silicon particles, reduces the graphene oxide to graphene, and imidizes the polyimide precursor to a polyimide, wherein the nanowire grows with a second part of the silicon particles used as a nucleus and extends into a needle by the heating. ### Claim 13 (depends on 12) The method for manufacturing the electrode according to claim 12, wherein the silicon particles have an average diameter of 10 nm to 1 μm before the heating. ### Claim 14 (depends on 12) The method for manufacturing the electrode according to claim 12, wherein the nanowire has a length of ten micrometers or more. ### Claim 15 (depends on 12) The method for manufacturing the electrode according to claim 12, wherein the heating is performed at a temperature equal to or greater than 360° C. and equal to or less than 400° C.