# US 12,113,216 B2 · Negative electrode active material for secondary batteries, and secondary battery > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,113,216 B2 - Document ID: US12113216B2 - Status: Granted - Kind: B2 - Application number: 17/270,519 - Filed: 2019-08-23 - Published: 2021-10-14 - Granted: 2024-10-08 - Earliest claimed: 2018-08-30 - Assignees: Panasonic Intellectual Property Management Co., Ltd. - Applicants: Panasonic Intellectual Property Management Co., Ltd. - Inventors: Yohei Uchiyama; Taisuke Asano; Yosuke Sato - Web page: https://patentgrep.com/patent/US12113216B2 ## CPC - H01M 4/5825: {Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines} - H01M 10/0431: {Cells with wound or folded electrodes (H01M10/045 takes precedence)} - H01M 4/381: {Alkaline or alkaline earth metals elements (H01M4/40 takes precedence)} - H01M 4/382: {Lithium (H01M4/405 takes precedence)} - H01M 4/386: {Silicon or alloys based on silicon} - H01M 50/103: prismatic or rectangular (H01M50/109, H01M50/11 take precedence) - H01M 2004/027: {Negative electrodes} - 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 A negative electrode active material for a secondary battery includes silicate composite particles each of which contain a silicate phase and silicon particles dispersed in the silicate phase, the silicate phase is an oxide phase containing Si, O, and alkali metals, and the alkali metals include at least Na and K. ## Claims ### Claim 1 A negative electrode active material for a secondary battery, comprising: silicate composite particles each of which contain a silicate phase and silicon particles dispersed in the silicate phase, wherein the silicate phase is an oxide phase which contains Si, O, and alkali metals, and the alkali metals include at least Na and K, and wherein, with respect to a total amount of elements other than O contained in the silicate phase, a content of Na is 7 percent by mole or more, a content of K is 7 percent by mole or more, and a total content of Na and K is 70 percent by mole to 40 percent by mole. ### Claim 2 (depends on 1) The negative electrode active material according to claim 1, wherein an atomic ratio: Na/K of Na to K contained in the silicate phase is 0.1 to 7. ### Claim 3 (depends on 1) The negative electrode active material according to claim 1, wherein the alkali metals further include Li. ### Claim 4 (depends on 3) The negative electrode active material according to claim 3, wherein a content of the alkali metals with respect to a total amount of elements other than O contained in the silicate phase is 80 percent by mole or less, and among the alkali metals, a total content of alkali metals other than a first alkali metal having a highest content is 7 percent by mole or more. ### Claim 5 (depends on 1) The negative electrode active material according to claim 1, wherein the silicate phase further contains a group 2 element, and a content of the group 2 element with respect to a total amount of elements other than O contained in the silicate phase is 20 percent by mole or less. ### Claim 6 (depends on 1) The negative electrode active material according to claim 1, wherein the silicate phase further contains an element M, and the element M is at least one selected from the group consisting of B, Al, Zr, Nb, Ta, La, V, Y, Ti, P, Bi, Zn, Sn, Pb, Sb, Co, Er, F, and W. ### Claim 7 (depends on 1) The negative electrode active material according to claim 1, wherein, in an X-ray diffraction pattern of the silicate composite particles, a ratio of an integrated value of a diffraction peak of each of all the other elements to an integrated value of a diffraction peak which belongs to the (111) plane of single Si is 0.5 or less. ### Claim 8 (depends on 1) The negative electrode active material according to claim 1, wherein the silicate composite particles have a void rate of less than 5 percent by volume. ### Claim 9 (depends on 1) The negative electrode active material according to claim 1, wherein an atomic ratio: Na/K of Na to K contained in the silicate phase is 0.1 to 1.0. ### Claim 10 (depends on 1) A secondary battery comprising: a positive electrode; a negative electrode; an electrolyte; and a separator provided between the positive electrode and the negative electrode, wherein the negative electrode includes a collector and a negative electrode active material layer, and the negative electrode active material layer contains the negative electrode active material according to claim 1. ### Claim 11 (depends on 10) The secondary battery according to claim 10, wherein, in a cross-sectional SEM-EDX analysis of the negative electrode active material layer in a discharge state, a ratio: I(Na/O) of an intensity which belongs to Na to an intensity which belongs to O is 0.02 to 0.7, a ratio: I(K/O) of an intensity which belongs to K to the intensity which belongs to O is 0.01 to 0.4, and a ratio: I(Na/K) of the intensity which belongs to Na to the intensity which belongs to K is 0.1 to 18. ### Claim 12 (depends on 10) The secondary battery according to claim 10, wherein, in a cross-sectional SEM-EDX analysis of the negative electrode active material layer in a discharge state, a ratio: I(Ca/O) of an intensity which belongs to Ca to an intensity which belongs to O is 0.5 or less.