# US 12,191,458 B2 · Protection method and device for secondary battery, secondary battery, battery module, battery pack, and electric apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,191,458 B2 - Document ID: US12191458B2 - Status: Granted - Kind: B2 - Application number: 18/592,946 - Filed: 2024-03-01 - Published: 2024-08-01 - Granted: 2025-01-07 - Earliest claimed: 2022-06-16 - Assignees: Contemporary Amperex Technology (Hong Kong) Limited - Applicants: Contemporary Amperex Technology (Hong Kong) Limited - Inventors: Ting Li; Haizu Jin; Shaojun Niu; Huaichao Tang; Longqing Peng - Web page: https://patentgrep.com/patent/US12191458B2 ## CPC - C23C 16/045: {Coating cavities or hollow spaces, e.g. interior of tubes; Infiltration of porous substrates} - H01M 10/4235: {Safety or regulating additives or arrangements in electrodes, separators or electrolyte (H01M10/4242 takes precedence)} - C23C 16/0245: {by etching with a plasma} - C23C 16/345: {Silicon nitride} - C23C 16/401: {containing silicon} - C23C 16/402: {Silicon dioxide} - C23C 16/403: {of aluminium, magnesium or beryllium} - C23C 16/405: {of refractory metals or yttrium} - C23C 16/407: {of zinc, germanium, cadmium, indium, tin, thallium or bismuth} - C23C 16/4408: {by purging residual gases from the reaction chamber or gas lines} - C23C 16/505: using radio frequency discharges - C23C 16/56: After-treatment - H01M 10/0404: {Machines for assembling batteries} - H01M 50/571: Methods or arrangements for affording protection against corrosion; Selection of materials therefor - H01M 10/052: Li-accumulators - 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 protection method for a secondary battery includes evacuating the secondary battery through an injection opening of the secondary battery to within 100 kPa, introducing a first reactant into the secondary battery through the injection opening until a pressure of the secondary battery rises by more than 1 Pa and maintaining the pressure for more than 1 ms, evacuating the secondary battery through the injection opening to within 100 kPa, and introducing a second reactant into the secondary battery through the injection opening until the pressure rises by more than 1 Pa and maintaining the pressure for more than 1 ms, thereby forming a protection layer on an internal surface of the secondary battery. ## Claims ### Claim 1 A protection method for a secondary battery comprising an injection opening, the method comprising: step (1): evacuating the secondary battery through the injection opening to within 100 kPa, optionally to within 100 Pa; step (2): introducing a first reactant into the secondary battery through the injection opening until a pressure in the secondary battery rises by more than 1 Pa, optionally more than 1 kPa, and maintaining the pressure for more than 1 ms, optionally for 0.1s-600s; and optionally step (3): evacuating the secondary battery through the injection opening to within 100 kPa again, optionally to within 100 Pa; and step (4): introducing a second reactant into the secondary battery through the injection opening until the pressure rises by more than 1 Pa, optionally more than 1 kPa, and maintaining the pressure for more than 1 ms, optionally for 0.1s-600s; wherein the second reactant is capable of reacting with the first reactant to form a protection layer on an internal surface of the secondary batter battery. ### Claim 2 (depends on 1) The protection method according to claim 1, wherein the first reactant comprises at least one of a gaseous aluminum compound, silicon compound, tin compound, germanium compound, chromium compound, boron compound, titanium compound, vanadium compound, elemental zinc and zinc compound, zirconium compound, hafnium compound, and tantalum compound. ### Claim 3 (depends on 1) The protection method according to claim 1, wherein the second reactant comprises at least one of and/or plasma of at least one of H2O, O2, O3, H2, S, (NH4)2S, H2Se, Se, H2Te, Te, HF, TiF4, TaF5, C2H4, CHCl3, H2O2, NO2, N2O, NH3, N2H4, HCOOH, CH3COOH, and H2S. ### Claim 4 (depends on 1) The protection method according to claim 1, wherein in the steps (1)-(4), a temperature of the secondary battery is maintained at a temperature between 0° C. and 200° C. ### Claim 5 (depends on 1) The protection method according to claim 1, wherein the steps (1)-(4) are repeated 1-100,000 times. ### Claim 6 (depends on 1) The protection method according to claim 1, wherein the steps (1)-(2) are first repeated 1-10 times, and then the steps (1)-(4) are repeated 1-100,000 times. ### Claim 7 (depends on 1) The protection method according to claim 1, wherein the first reactant and the second reactant are introduced by using a carrier gas, the carrier gas comprising at least one of nitrogen, argon, carbon dioxide, and helium. ### Claim 8 (depends on 1) The protection method according to claim 1, further comprising, prior to the step (1): pre-treating the internal surface of the secondary battery, comprising introducing at least one of and/or plasma of at least one of Ar, N2, H2O, O2, O3, H2, S, (NH4)2S, H2Se, Se, H2Te, Te, HF, TiF4, TaF5, C2H4, CHCl3, H2O2, NO2, N2O, NH3, N2H4, HCOOH, CH3COOH, and H2S into the secondary battery through the injection opening. ### Claim 9 (depends on 1) The protection method according to claim 1, wherein: the secondary battery further comprises an electrode assembly, tabs, adapting pieces, a top cover assembly, and a housing; and the protection layer is formed at connections between the tabs and the adapting pieces, at connections between the adapting pieces and the top cover assembly, at a connection between the top cover assembly and the housing, at an inner wall of the top cover assembly, on the adapting pieces, at an inner wall of the housing, and at an outer peripheral surface of the electrode assembly. ### Claim 10 (depends on 1) The protection method according to claim 1, wherein the protection layer comprises at least one of carbides, nitrides, sulfides, oxides, fluorides, selenides, and tellurides of aluminum, silicon, tin, germanium, chromium, boron, titanium, vanadium, zinc, zirconium, hafnium, or tantalum. ### Claim 11 (depends on 1) The protection method according to claim 1, further comprising: purging the secondary battery with a purge gas after the step (2) and/or the step (4), the purge gas comprising at least one of N2, Ar, He, CO2, and the second reactant. ### Claim 12 (depends on 1) The protection method according to claim 1, wherein a thickness of the protection layer is 1 nm-1000 μm. ### Claim 13 (depends on 1) The protection method according to claim 1, further comprising: performing post-treatment on the protection layer, comprising temperature annealing treatment, plasma annealing treatment, or light radiation annealing treatment in a specific atmosphere, wherein the specific atmosphere comprises at least one of and/or plasma of at least one of pyridine, N2, Ar, He, CO2, and the second reactant. ### Claim 14 (depends on 1) A secondary battery, wherein the secondary battery is a secondary battery obtained through protection using the protection method according to claim 1. ### Claim 15 (depends on 14) A battery module, comprising the secondary battery according to claim 14. ### Claim 16 (depends on 15) A battery pack, comprising the battery module according to claim 15. ### Claim 17 (depends on 14) An electric apparatus, comprising the secondary battery according to claim 14. ### Claim 18 A protection device for a secondary battery, comprising: a cavity for accommodating the secondary battery; a first reactant tank for storing a first reactant; a second reactant tank for storing a second reactant; a vacuum pump; a pressure gauge for real-time monitoring of a pressure within the secondary battery; and a flow regulating valve for regulating a flow rate of the first reactant and a flow rate of the second reactant; wherein: the second reactant being capable of reacting with the first reactant to form a protection layer; and the first reactant tank and the second reactant tank are in communication with an injection opening of the secondary battery accommodated in the cavity for introducing the first reactant and the second reactant into the secondary battery; and the vacuum pump is in communication with the injection opening of the secondary battery accommodated in the cavity for evacuating the secondary battery.