# US 12,218,311 B2 · Secondary battery, battery module, battery pack, and electrical device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,218,311 B2 - Document ID: US12218311B2 - Status: Granted - Kind: B2 - Application number: 18/366,342 - Filed: 2023-08-07 - Published: 2023-11-23 - Granted: 2025-02-04 - Earliest claimed: 2021-10-29 - Assignees: Contemporary Amperex Technology (Hong Kong) Limited - Applicants: Contemporary Amperex Technology (Hong Kong) Limited - Inventors: Quanguo Li; Yonghuang Ye; Qian Liu; Jianfu He; Fajun Huang; Chenhui Lin - Web page: https://patentgrep.com/patent/US12218311B2 ## CPC - H01M 10/0585: of accumulators having only flat construction elements, i.e. flat positive electrodes, flat negative electrodes and flat separators - H01M 4/381: {Alkaline or alkaline earth metals elements (H01M4/40 takes precedence)} - 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 4/5825: {Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines} - H01M 4/583: Carbonaceous material, e.g. graphite-intercalation compounds or CFx - H01M 4/622: {being polymers} - H01M 4/623: {fluorinated polymers} - H01M 4/625: {Carbon or graphite} - 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 2004/028: {Positive electrodes} - H01M 2220/20: Batteries in motive systems, e.g. vehicle, ship, plane - 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 secondary battery includes a positive electrode plate. that includes a positive current collector, a first positive active material layer distributed on one side of the positive current collector, and a second positive active material layer distributed on an other side of the positive current collector and a negative electrode plate that includes a negative current collector, a first negative active material layer distributed on one side of the negative current collector and opposite to the second positive active material layer, and a second negative active material layer distributed on an other side of the negative current collector. A resistance of the first positive active material layer is R1, a resistance of the second positive active material layer is R2, a resistance of the first negative active material layer is R3, a resistance of the second negative active material layer is R4. ## Claims ### Claim 1 A secondary battery, wherein the secondary battery comprises a positive electrode plate, a negative electrode plate, and a separator between the positive electrode plate and the negative electrode plate: wherein the positive electrode plate comprises a positive current collector, a first positive active material layer distributed on one side of the positive current collector and a second positive active material layer distributed on another side of the positive current collector; wherein the negative electrode plate comprises a negative current collector, a first negative active material layer distributed on one side of the negative current collector and opposite to the second positive active material layer and a second negative active material layer distributed on another side of the negative current collector; a coating weight of a positive active material per unit area of the first positive active material layer is CW1 and a coating weight of the positive active material per unit area of the second positive active material layer is CW2; wherein 6.5 mg/cm2≤CW1≤32.5 mg/cm2, 6.5 mg/cm2≤CW2≤32.5 mg/cm2 and 0.5≤CW1/CW2<1; wherein the first negative active material layer and the second negative active material layer are different in composition and wherein, a resistance of the first positive active material layer is R1, a resistance of the second positive active material layer is R2, a resistance of the first negative active material layer is R3, a resistance of the second negative active material layer is R4, and the resistances R1, R2, R3, and R4 are Ohmic resistances and satisfy the following relationships: R2>R1; (1) R3≥R4; (2) 0<(R1+R4)/(R2+R3)≤1; and (3) R1/R2=A×R4/R3, wherein A is 0.8 to 1.2, (4) wherein R1 is 0.1Ω to 20Ω, R2 is 0.15Ω to 22Ω, R3 is 0.7 mΩ to 40 mΩ, and R4 is 0.5 mΩ to 35 mΩ. ### Claim 2 (depends on 1) The secondary battery according to claim 1, wherein A is 0.95 to 1.05. ### Claim 3 (depends on 1) The secondary battery according to claim 1, wherein R1 is 0.5Ω to 10Ω, R2 is 0.55Ω to 12Ω, R3 is 1 mΩ to 30 mΩ, and R4 is 1.1 mΩ to 30 mΩ. ### Claim 4 (depends on 1) The secondary battery according to claim 1, wherein a coating weight of a negative active material per unit area of the first negative active material layer is CW3, a coating weight of the negative active material per unit area of the second negative active material layer is CW4, wherein 5.2 mg/cm2