# US 2021/0280862 A1 · Cathode active material for lithium secondary battery, method for preparing same, and lithium secondary battery comprising same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0280862 A1 - Document ID: US20210280862A1 - Status: Published application - Kind: A1 - Application number: 16/320,057 - Filed: 2017-08-22 - Published: 2021-09-09 - Earliest claimed: 2016-08-23 - Assignees: Samsung SDI Co., Ltd. - Applicants: Samsung SDI Co., Ltd. - Inventors: Jungmin HAN; Kihyun KIM; Jaeho LEE; Ming-Zi HONG - Web page: https://patentgrep.com/patent/US20210280862A1 ## CPC - H01M 4/131: Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx - H01M 4/505: of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy - H01M 4/366: {as layered products} - H01M 4/382: {Lithium (H01M4/405 takes precedence)} - 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 4/525: of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy - 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 - 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 Provided are a cathode active material for a lithium secondary battery, a method for preparing the same, and a lithium secondary battery comprising the same. The cathode active material for a lithium secondary battery comprises: a lithium metal compound; and a lithium compound disposed on the surface of the lithium metal compound, wherein the content of lithium contained in the lithium compound is 0.25 parts by weight or less with respect to 100 parts by weight of the lithium metal compound, wherein the specific surface area of the lithium compound is between 0.5 m2/g and 2.0 m2/g, and the pH of the lithium compound is between 11.5 and 12.3. ## Claims ### Claim 1 A cathode active material for a lithium secondary battery, comprising a lithium metal compound and a lithium compound disposed on the surface of the lithium metal compound, wherein the lithium metal compound is different from the lithium compound, the content of lithium contained in the lithium compound is 0.25 parts by weight or less with respect to 100 parts by weight of the lithium metal compound, a specific surface area is 0.5 m2/g to 2.0 m2/g, and pH is 11.5 to 12.3. ### Claim 2 (depends on 1) The cathode active material for a lithium secondary battery of claim 1, wherein the content of lithium contained in the lithium compound is 0.05 parts by weight to 0.25 parts by weight with respect to 100 parts by weight of the lithium metal compound. ### Claim 3 (depends on 1) The cathode active material for a lithium secondary battery of claim 1, wherein a specific surface area of the cathode active material is 0.5 m2/g to 1.90 m2/g. ### Claim 4 (depends on 1) The cathode active material for a lithium secondary battery of claim 1, wherein the pH of the cathode active material is 11.5 to 12.1. ### Claim 5 (depends on 1) The cathode active material for a lithium secondary battery of claim 1, wherein the lithium metal compound comprises a nickel-based oxide represented by Chemical Formula 1: Lia(NixM′yM″z)O2 [Chemical Formula 1] wherein, in Chemical Formula 1, M′ is at least one selected from Co, Mn, Ni, Al, Mg, and Ti, M″ is at least one selected from Ca, Mg, Al, Ti, Sr, Fe, Co, Mn, Ni, Cu, Zn, Y, Zr, Nb, and B, 0.8