# US 12,770,864 B2 · Composite particles, negative electrode mixture layer 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 12,770,864 B2 - Document ID: US12770864B2 - Status: Granted - Kind: B2 - Application number: 18/290,333 - Filed: 2022-05-26 - Published: 2024-07-25 - Granted: 2026-10-20 - Earliest claimed: 2021-05-28 - Assignees: Group14 Technologies, Inc. - Applicants: Group 14 Technologies, Inc. - Inventors: Yuji Ito; Masato Fujita; Akihisa Tonegawa; Takayuki Kurita; Hirofumi Inoue - Web page: https://patentgrep.com/patent/US12770864B2 ## CPC - H01M 4/366: {as layered products} - H01M 4/386: {Silicon or alloys based on silicon} - H01M 4/587: for inserting or intercalating light metals - H01M 10/0525: Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries - H01M 2004/021: {Physical characteristics, e.g. porosity, surface area} - H01M 2004/027: {Negative electrodes} - H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY ## Abstract One embodiment of the present invention is composite particles containing silicon and carbon, which are characterized as follows. When the cross-sectional diameter and the silicon content rate of the composite particles are measured by cross-sectional SEM-EDS and composite particles having a cross-sectional diameter of half or less than the number average of the cross-sectional diameter are defined as small diameter composite particles, the proportion of the number of the small diameter composite particles in the number of the composite particles measured is 5% or more and 50% or less, the ratio of the average silicon content rate (% by mass) of particles other than the small diameter composite particles to the average silicon content rate (% by mass) of the small diameter composite particles is 0.90 or less, and the silicon content rate of the entire composite particles is 45% by mass or more. ## Claims ### Claim 1 Composite particles comprising silicon and carbon, wherein, when a cross-sectional diameter and a silicon content rate of the composite particles are measured by cross-sectional SEM-EDS and composite particles having a cross-sectional diameter of ½ or less of a number average of the cross-sectional diameter are defined as small diameter composite particles, a proportion of the number of the small diameter composite particles in the number of the composite particles measured is 5% or more and 50% or less, a ratio of an average silicon content rate (% by mass) of particles other than the small diameter composite particles to an average silicon content rate (% by mass) of the small diameter composite particles is 0.90 or less, and a silicon content rate of entire composite particles is 45% by mass or more. ### Claim 2 (depends on 1) The composite particles according to claim 1, wherein the carbon comprises a porous carbon material. ### Claim 3 (depends on 1) The composite particles according to claim 1, having a pore volume of 0.10 cm3/g or less. ### Claim 4 (depends on 1) The composite particles according to claim 1, wherein a ratio of an oxygen content rate (% by mass) to a silicon content rate (% by mass) is 0.001 or more and 0.300 or less. ### Claim 5 (depends on 1) The composite particles according to claim 1, wherein a peak is present between 450 and 495 cm−1 in a Raman spectrum. ### Claim 6 (depends on 1) The composite particles according to claim 1, wherein (peak height of SiC111 plane)/(peak height of Si111 plane) is 0.010 or less, in an XRD pattern as measured by powder XRD using a Cu-Kα radiation. ### Claim 7 (depends on 1) The composite particles according to claim 1, wherein, when the small diameter composite particles are analyzed by SEM-EDS, one or more elements selected from Al, Ti, V, Cr, Mn, Fe, Co, Ni, Y, Zr, Mo, Nb, La, Ce, Ta, and W are detected. ### Claim 8 (depends on 1) The composite particles according to claim 1, comprising: 5 to 50% by mass of composite particles(S) obtained by allowing a silane gas to act on porous carbon(S) having a DV50 of 1.0 to 10.0 μm and a pore volume of 0.8 to 2.2 cm3/g to thereby fill in pores of the porous carbon(S) with silicon; and 50 to 95% by mass of composite particles (L) obtained by allowing a silane gas to act on porous carbon (L) having a DV50 greater than that of the porous carbon(S) and a pore volume of 0.2 to 0.8 cm3/g to thereby fill in pores of the porous carbon (L) with silicon, provided that a sum of the composite particles(S) and the composite particles (L) is 100% by mass. ### Claim 9 (depends on 1) A negative electrode mixture layer comprising the composite particles according to claim 1. ### Claim 10 (depends on 9) A lithium-ion secondary battery comprising the negative electrode mixture layer according to claim 9.