# US 11,993,846 B2 · Method of preparing positive electrode active material for secondary battery > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,993,846 B2 - Document ID: US11993846B2 - Status: Granted - Kind: B2 - Application number: 17/781,925 - Filed: 2021-01-12 - Published: 2023-01-05 - Granted: 2024-05-28 - Earliest claimed: 2020-01-14 - Assignees: LG Energy Solution, Ltd. - Applicants: LG Energy Solution, Ltd. - Inventors: Seul Ki Chae; Dae Jin Lee; Dong Hwi Kim; Jin Tae Hwang; Hyeong Il Kim; Wang Mo Jung; Dong Hun Lee - Web page: https://patentgrep.com/patent/US11993846B2 ## CPC - C23C 16/45555: {applied in non-semiconductor technology} - C23C 16/4417: {Methods specially adapted for coating powder} - C23C 16/45534: {Use of auxiliary reactants other than used for contributing to the composition of the main film, e.g. catalysts, activators or scavengers} - H01M 4/0428: {Chemical vapour deposition} - H01M 4/366: {as layered products} - H01M 4/505: of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy - 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 4/62: Selection of inactive substances as ingredients for active masses, e.g. binders, fillers - H01M 2004/028: {Positive electrodes} - Y02E 60/10: Energy storage using batteries - C23C: COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL (making metal-coated products by extrusion B21C23/22; covering with metal by connecting pre-existing layers to articles, see the relevant places, e.g. B21D39/00, B23K; metallising of glass C03C; metallising mortars, concrete, artificial stone, ceramics or natural stone C04B41/00; enamelling of, or applying a vitreous layer to, metals C23D; treating metal surfaces or coating of metals by electrolysis or electrophoresis C25D; single-crystal film growth C30B; by metallising textiles D06M11/83; decorating textiles by locally metallising D06Q1/04) - 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 method of preparing a positive electrode active material for a secondary battery includes preparing a lithium composite transition metal oxide which includes nickel, cobalt, and manganese and contains 60 mol % or more of the nickel among all metals except lithium, adding a moisture absorbent and the lithium composite transition metal oxide into an atomic layer deposition (ALD) reactor, and adding a coating metal precursor into the atomic layer deposition (ALD) reactor and forming a metal oxide coating layer on surfaces of particles of the lithium composite transition metal oxide by atomic layer deposition (ALD). ## Claims ### Claim 1 A method of preparing a positive electrode active material for a secondary battery, the method comprising: preparing a lithium composite transition metal oxide which includes nickel, cobalt, and manganese and contains 60 mol % or more of the nickel among all metals except lithium; adding a moisture absorbent and the lithium composite transition metal oxide into an atomic layer deposition (ALD) reactor; and adding a coating metal precursor into the atomic layer deposition (ALD) reactor, and forming a metal oxide coating layer from the coating metal precursor on surfaces of particles of the lithium composite transition metal oxide by an atomic layer deposition (ALD). ### Claim 2 (depends on 1) The method of claim 1, wherein the moisture absorbent is at least one selected from the group consisting of P2O5, K2O, CaO, Na2O, zeolite, LiO, and MgO. ### Claim 3 (depends on 1) The method of claim 1, wherein a moisture content of the lithium composite transition metal oxide in the atomic layer deposition (ALD) reactor is 300 ppm or less before performing the atomic layer deposition (ALD). ### Claim 4 (depends on 3) The method of claim 3, wherein the moisture content of the lithium composite transition metal oxide in the atomic layer deposition (ALD) reactor is 200 ppm to 250 ppm. ### Claim 5 (depends on 1) The method of claim 1, wherein inside of the atomic layer deposition (ALD) reactor is in a vacuum state before performing the atomic layer deposition (ALD). ### Claim 6 (depends on 1) The method of claim 1, wherein the metal oxide coating layer comprises at least one selected from the group consisting of Al2O3, TiO2, SiO2, ZrO2, VO2, V2O5, Nb2O5, MgO, TaO2, Ta2O5, B2O2, B403, B405, ZnO, SnO, HfO2, Er2O3, La2O3, In203, Y2O3, Ce2O3, Sc2O3, or W2O3. ### Claim 7 (depends on 1) The method of claim 1, wherein a thickness of the metal oxide coating layer is 1.5 nm or less. ### Claim 8 (depends on 7) The method of claim 7, wherein the thickness of the metal oxide coating layer is in a range of 0.8 nm to 1.2 nm. ### Claim 9 (depends on 1) The method of claim 1, wherein the atomic layer deposition (ALD) is performed for 1 cycle to 8 cycles. ### Claim 10 (depends on 1) The method of claim 1, wherein the lithium composite transition metal oxide is represented by Formula 1: LiaNi1-b-c-dCobMncQdO2+δ [Formula 1] wherein, Q is at least one element selected from the group consisting of aluminum (Al), magnesium (Mg), vanadium (V), titanium (Ti), and zirconium (Zr), 1.0≤a≤1.5, 0