# US 12,218,346 B2 · Method of extending cycle-life of a lithium metal secondary battery > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,218,346 B2 - Document ID: US12218346B2 - Status: Granted - Kind: B2 - Application number: 16/113,676 - Filed: 2018-08-27 - Published: 2019-12-26 - Granted: 2025-02-04 - Earliest claimed: 2018-06-21 - Assignees: Honeycomb Battery Company - Applicants: Nanotek Instruments, Inc. - Inventors: Hui He; Aruna Zhamu; Bor Z. Jang - Web page: https://patentgrep.com/patent/US12218346B2 ## CPC - H01M 4/382: {Lithium (H01M4/405 takes precedence)} - H01M 4/133: Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx - H01M 4/134: Electrodes based on metals, Si or alloys - H01M 4/366: {as layered products} - H01M 4/405: {Alloys based on lithium} - H01M 4/622: {being polymers} - H01M 4/624: {Electric conductive fillers} - H01M 4/625: {Carbon or graphite} - H01M 10/052: Li-accumulators - H01M 10/0525: Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries - H01M 10/4235: {Safety or regulating additives or arrangements in electrodes, separators or electrolyte (H01M10/4242 takes precedence)} - H01M 50/46: Separators, membranes or diaphragms characterised by their combination with electrodes - H01M 2004/027: {Negative electrodes} - H01M 2004/028: {Positive electrodes} - H01M 2004/8684: {Negative electrodes} - 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 The invention provides a method of improving the cycle-life of a lithium metal secondary battery. The method comprises implementing an anode-protecting layer between an anode active material layer and a porous separator/electrolyte, wherein the anode-protecting layer or cathode-protecting layer comprises a conductive sulfonated elastomer composite having from 0.01% to 40% by weight of a conductive reinforcement material and from 0.01% to 40% by weight of an electrochemically stable inorganic filler dispersed in a sulfonated elastomeric matrix material and the protecting layer has a thickness from 1 nm to 100 μm, a fully recoverable tensile strain from 2% to 500%, a lithium ion conductivity from 10−7 S/cm to 5×10−2 S/cm, and an electrical conductivity from 10−7 S/cm to 100 S/cm when measured at room temperature. ## Claims ### Claim 1 A method of improving a cycle-life of a lithium metal secondary battery, not including a lithium-sulfur battery or lithium-selenium battery, said method comprising implementing an anode-protecting layer between an anode active material layer and a porous separator/electrolyte, wherein said anode-protecting layer comprises a conductive sulfonated elastomer composite having from greater than 20% to 40% by weight of a conductive reinforcement material and from 0.01% to 40% by weight of an electrochemically stable inorganic filler dispersed in a sulfonated elastomeric matrix material and said layer of conductive sulfonated elastomer composite has a thickness from 1 nm to 100 μm, a fully recoverable tensile strain from 2% to 500%, a lithium ion conductivity from 10−7 S/cm to 5×10−2 S/cm, and an electrical conductivity from 10−7 S/cm to 100 S/cm when measured at room temperature and wherein said inorganic filler has a lithium intercalation potential from 1.1 V to 4.5 V versus Li/Li+ and is selected from a carbide, boride, nitride, sulfide, or phosphide of a transition metal, a lithiated version thereof, or a combination thereof, wherein said transition metal is selected from the group consisting of combinations of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Pd, Ag, Cd, La, Ta, W, Pt, Au, and Hg with Ga, In, or Sb. ### Claim 2 (depends on 1) The method of claim 1, wherein said step of implementing an anode-protecting layer is conducted by depositing a layer of a sulfonated elastomer composite onto one primary surface of the anode active material layer to form a protected anode, optionally compressing said protected anode to improve a contact between said anode-protecting layer and said anode active material layer, followed by combining the protected anode, the separator/electrolyte, and the cathode together to form said lithium metal secondary battery. ### Claim 3 (depends on 1) The method of claim 1, wherein said step of implementing an anode-protecting layer is conducted by depositing a layer of first sulfonated elastomer composite onto one primary surface of the separator to form a coated separator, followed by combining the anode, the coated separator, the cathode, and the electrolyte together to form the lithium metal secondary battery. ### Claim 4 (depends on 1) The method of claim 1, wherein said step of implementing an anode-protecting layer is conducted by forming a layer of a sulfonated elastomer composite, followed by laminating the anode layer, the layer of sulfonated elastomer composite, the separator layer, the cathode layer, along with the electrolyte to form the lithium metal secondary battery, wherein an optional compressive stress is applied to improve a contact between said anode-protecting layer and said anode active material layer during or after said laminating step. ### Claim 5 (depends on 1) The method of claim 1, wherein said sulfonated elastomer matrix further contains from 0.1% to 50% by weight of a lithium ion-conducting additive dispersed therein. ### Claim 6 (depends on 5) The method of claim 5, wherein said lithium ion-conducting additive is selected from the group consisting of poly (ethylene oxide) (PEO), polypropylene oxide (PPO), poly (acrylonitrile) (PAN), poly (methyl methacrylate) (PMMA), poly (vinylidene fluoride) (PVDF), poly bis-methoxy ethoxyethoxide-phosphazene, polyvinyl chloride, polydimethylsiloxane, poly (vinylidene fluoride)-hexafluoropropylene (PVDF-HFP), a sulfonated derivative thereof, and combinations thereof. ### Claim 7 (depends on 1) The method of claim 1, wherein said electrolyte is selected from a polymer electrolyte, polymer gel electrolyte, composite electrolyte, ionic liquid electrolyte, organic liquid electrolyte, solid-state electrolyte, or a combination thereof. ### Claim 8 (depends on 1) The method of claim 1, wherein said cathode active material is selected from an inorganic material, an organic material, a polymeric material, or a combination thereof, and said inorganic material does not include sulfur or alkali metal polysulfide. ### Claim 9 (depends on 8) The method of claim 8, wherein said inorganic material is selected from a metal oxide, metal phosphate, metal silicide, metal selenide, transition metal sulfide, or a combination thereof. ### Claim 10 (depends on 9) The method of claim 9, wherein said metal oxide contains a vanadium oxide selected from the group consisting of VO2, LixVO2, V2O5, LixV2O5, V3O8, LixV3O8, LixV3O7, V4O9, LixV4O9, V6O13, LixV6O13, their doped versions, their derivatives, and combinations thereof, wherein 0.1