# US 11,909,038 B2 · Negative electrode active material, negative electrode, lithium ion secondary battery, method of producing negative electrode active material, and method of producing 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 11,909,038 B2 - Document ID: US11909038B2 - Status: Granted - Kind: B2 - Application number: 16/339,429 - Filed: 2017-08-23 - Published: 2019-08-01 - Granted: 2024-02-20 - Earliest claimed: 2016-10-21 - Assignees: Shin-Etsu Chemical Co., Ltd. - Applicants: Shin-Etsu Chemical Co., Ltd. - Inventors: Takakazu Hirose; Reiko Sakai - Web page: https://patentgrep.com/patent/US11909038B2 ## CPC - H01M 4/386: {Silicon or alloys based on silicon} - H01M 4/48: of inorganic oxides or hydroxides - C01B 33/113: Silicon oxides; Hydrates thereof {(preparing monoxide by reduction of siliceous material C01B33/182)} - H01M 4/131: Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx - H01M 4/134: Electrodes based on metals, Si or alloys - H01M 4/1395: of electrodes based on metals, Si or alloys - H01M 4/36: Selection of substances as active materials, active masses, active liquids - H01M 4/364: {as mixtures} - H01M 4/366: {as layered products} - H01M 4/485: of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy (H01M4/505, H01M4/525 take precedence) - H01M 4/62: Selection of inactive substances as ingredients for active masses, e.g. binders, fillers - H01M 10/0525: Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries - H01M 10/058: Construction or manufacture - H01M 2004/021: {Physical characteristics, e.g. porosity, surface area} - H01M 2004/027: {Negative electrodes} - Y02E 60/10: Energy storage using batteries - Y02P 70/50: Manufacturing or production processes characterised by the final manufactured product - H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY - C01B: NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; {METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C} - 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 ## Abstract A negative electrode active material containing a negative electrode active material particle; the negative electrode active material particle including a silicon compound shown by SiOx (0.5≤x≤1.6), and having a peak in a range of 539 to 541 eV in a XANES spectrum obtained by XANES measurement of the negative electrode active material particle. This provides a negative electrode active material that is capable of increasing battery capacity and improving cycle performance when it is used as a negative electrode active material for a secondary battery. ## Claims ### Claim 1 A negative electrode active material comprising a negative electrode active material particle having: (i) a peak in a range of 539 to 541 eV in a XANES spectrum that is obtained by XANES measurement of the negative electrode active material particle, and (ii) a strongest peak at the vicinity of 532 eV in the XANES spectrum; wherein the negative electrode active material particle exhibits a decrease in the strongest peak at the vicinity of 532 eV in occlusion of Li, the negative electrode active material particle exhibits a peak generated at the vicinity of 534 eV in the XANES spectrum in occlusion of Li, wherein Li is inserted into a Si—O bond to reduce at least part of Si—O bonds and to form a Li—Si bond or an O—Li bond, and the peak at the vicinity of 532 eV is attributable to Si—O bonds which contribute to occlusion of Li; and the negative electrode active material particle comprises a silicon compound shown by SiOx, where 0.5≤x≤1.6 wherein the silicon compound comprises a silicon dioxide (SiO2) component and a silicon (Si) component. ### Claim 2 (depends on 1) The negative electrode active material according to claim 1, wherein a median diameter of the negative electrode active material particle is 0.5 μm or more and 20 μm or less. ### Claim 3 (depends on 1) The negative electrode active material according to claim 1, wherein the negative electrode active material particle has a surface layer portion containing a carbon material. ### Claim 4 (depends on 3) The negative electrode active material according to claim 3, wherein a median diameter of the negative electrode active material particle is 0.5 μm or more and 20 μm or less. ### Claim 5 (depends on 3) The negative electrode active material according to claim 3, wherein an average thickness of the carbon material is 5 nm or more and 5000 nm or less. ### Claim 6 (depends on 1) A negative electrode comprising the negative electrode active material according to claim 1. ### Claim 7 (depends on 6) A lithium ion secondary battery, comprising the negative electrode according to claim 6 as a negative electrode. ### Claim 8 (depends on 1) A method of producing the negative electrode active material according to claim 1, the method comprising: preparing negative electrode active material particles each containing the silicon compound; and selecting the negative electrode active material particle having: (i) the peak in the range of 539 to 541 eV in the XANES spectrum and (ii) the strongest peak at the vicinity of 532 eV in the XANES spectrum. ### Claim 9 (depends on 8) A method of producing a lithium ion secondary battery, comprising: producing a negative electrode active material using the method according to claim 8, producing a negative electrode using the negative electrode active material, and producing a lithium ion secondary battery using the negative electrode. ### Claim 10 (depends on 1) The negative electrode active material according to claim 1, wherein the peak in the range of 539 to 541 eV is attributable to the Si—O bond. ### Claim 11 (depends on 8) The method according to claim 8, wherein the peak in the range of 539 to 541 eV is attributable to the Si—O bond.