# US 9,520,593 B2 · Method of preparing cathode active material precursor for lithium rechargeable battery, cathode active material precursor for lithium rechargeable battery prepared thereby, and cathode active material formed using the cathode active material precursor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,520,593 B2 - Document ID: US9520593B2 - Status: Granted - Kind: B2 - Application number: 14/389,502 - Filed: 2013-03-29 - Published: 2015-02-26 - Granted: 2016-12-13 - Earliest claimed: 2012-03-31 - Assignees: Iucf-Hyu (Industry-University Cooperation Foundation Hanyang University) - Applicants: Iucf-Hyu (Industry-University Cooperation Foundation Hanyang University) - Inventors: Yang-Kook Sun; Hyung Joo Noh - Web page: https://patentgrep.com/patent/US9520593B2 ## CPC - H01M 4/364: {as mixtures} - C01G 53/44: containing manganese - H01M 4/02: Electrodes composed of, or comprising, active material - H01M 4/1391: of electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx - 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 4/52: of nickel, cobalt or iron - 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 - C01P 2002/88: by thermal analysis data, e.g. TGA, DTA, DSC - C01P 2004/84: one phase coated with the other - C01P 2006/40: Electric properties - H01M 4/505: of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy - 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 - C01G: COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F (metal hydrides {monoborane, diborane or addition complexes thereof} C01B6/00; salts of oxyacids of halogens C01B11/00; peroxides, salts or peroxyacids C01B15/00; thiosulfates, dithionites, polythionates C01B17/64; compounds containing selenium, or tellurium C01B19/00; binary compounds of nitrogen with metals C01B21/06; azides C01B21/08; {compounds containing nitrogen, other non-metals and metal C01B21/082}; metal amides C01B21/092; nitrites C01B21/50; {compounds of noble gases C01B23/0005}; phosphides C01B25/08; salts of oxyacids of phosphorus C01B25/16; carbides C01B32/90; compounds containing silicon C01B33/00; compounds containing boron C01B35/00; compounds having molecular sieve properties but not having base-exchange properties C01B37/00; compounds having molecular sieve and base-exchange properties, e.g. crystalline zeolites, C01B39/00; cyanides C01C3/08; salts of cyanamide C01C3/16; thiocyanates C01C3/20) - C01P: INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS - 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 The present invention relates to a method of preparing a cathode active material precursor for a lithium rechargeable battery, the cathode active material precursor for the lithium rechargeable battery prepared thereby, and a cathode active material formed using the cathode active material precursor. According to the present invention, the method of preparing a cathode active material precursor for a lithium secondary battery controls the concentration of a concentration gradient part and a shell part in a precursor to obtain a desired concentration of a transition metal in the shell part. As a result, a metal composition is distributed in a continuous concentration gradient from the interface between the core part and the shell part to the surface of the cathode active material, thereby a cathode active material with excellent thermal stability. ## Claims ### Claim 1 A method of preparing a cathode active material precursor for a lithium rechargeable battery, the method comprising: preparing a metallic salt aqueous solution for formation of a core part and a metallic salt aqueous solution for formation of a shell part that include nickel, cobalt, and manganese as metallic salts; providing a first chelating agent, a first alkaline aqueous solution, the metallic salt aqueous solution for the formation of the core part, and the metallic salt aqueous solution for the formation of the shell part into a reactor while changing a mixing ratio of the metallic salt aqueous solution for the formation of the core part and the metallic salt aqueous solution for the formation of the shell part, thereby forming a concentration gradient part of which concentrations of metallic salts are gradually changed; providing a second chelating agent, a second alkaline aqueous solution, the metallic salt aqueous solution for the formation of the core part, and the metallic salt aqueous solution for the formation of the shell part into the reactor while mixing the metallic salt aqueous solution for the formation of the core part and the metallic salt aqueous solution for the formation of the shell part at a fixed ratio, thereby forming a shell part having a fixed concentration; and drying and heating a formed precipitate to prepare an active material precursor, wherein a concentration of a specific metallic salt of the concentration gradient part in a contact portion of the concentration gradient part and the shell part is denoted by “MC”, and a concentration of the specific metallic salt of the shell part in the contact portion of the concentration gradient part and the shell part is denoted by “MS”, and wherein the MC and the MS satisfy a relation formula MC≠MS. ### Claim 2 (depends on 1) The method of claim 1, wherein a concentration of the specific metallic salt at a center of the concentration gradient part is denoted by “MCO”, wherein the MC and the MS satisfy a relation formula MCMS when the MCO and the MC satisfy a relation formula MCO>MC. ### Claim 4 (depends on 2) The method of claim 2, wherein a difference between the MS and the MC is in a range of 2 mol % to 40 mol %. ### Claim 5 (depends on 3) The method of claim 3, wherein a difference between the MS and the MC is in a range of 2 mol % to 30 mol %. ### Claim 6 (depends on 2) The method of claim 2, wherein a metal of the specific metallic salt satisfying the relation formula MCOMC is cobalt and manganese. ### Claim 8 (depends on 1) The method of claim 1, further comprising: providing a third chelating agent, a third alkaline aqueous solution, and the metallic salt aqueous solution for the formation of the core part to form a core part between preparing the metallic salt aqueous solution for the formation of the core part and the metallic salt aqueous solution for the formation of the shell part; and providing the chelating agent, the alkaline aqueous solution, the metallic salt aqueous solution for the formation of the core part, and the metallic salt aqueous solution for the formation of the shell part into the reactor while changing a mixing ratio of the metallic salt aqueous solution for the formation of the core part and the metallic salt aqueous solution for the formation of the shell part, thereby preparing the concentration gradient part. ### Claim 9 (depends on 1) The method of claim 1, wherein the metallic salt aqueous solution for the formation of the shell part is used in plurality, and the plurality of the metallic salt aqueous solutions for the formation of the shell part have concentrations different from each other. ### Claim 10 (depends on 1) The method of claim 1, wherein the concentration gradient part includes a metallic salt of which a concentration gradient is changed. ### Claim 11 (depends on 1) A cathode active material precursor for a lithium rechargeable battery prepared by the method of claim 1. ### Claim 12 (depends on 1) A method of preparing a cathode active material for a lithium rechargeable battery, the method comprising: mixing the cathode active material precursor prepared by claim 1 with lithium salt; and firing the mixture of the cathode active material precursor and the lithium salt to obtain a lithium composite metal oxide. ### Claim 13 (depends on 12) A cathode active material for a lithium rechargeable battery prepared by claim 12.