# US 7,608,350 B2 · Preparation and storage of membrane and electrode assemblies > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,608,350 B2 - Document ID: US7608350B2 - Status: Granted - Kind: B2 - Application number: 10/828,507 - Filed: 2004-04-19 - Published: 2005-01-06 - Granted: 2009-10-27 - Earliest claimed: 2003-04-17 - Assignees: Lynntech, Inc. - Inventors: Oliver J. Murphy; Carlos Salinas - Web page: https://patentgrep.com/patent/US7608350B2 ## CPC - H01M 8/1004: characterised by membrane-electrode assemblies [MEA] (H01M8/12 takes precedence) - C25B 9/23: comprising ion-exchange membranes in or on which electrode material is embedded - H01M 4/881: {Electrolytic membranes} - H01M 8/0271: Sealing or supporting means around electrodes, matrices or membranes - H01M 8/04067: {Heat exchange or temperature measuring elements, thermal insulation, e.g. heat pipes, heat pumps, fins} - H01M 4/90: Selection of catalytic material - H01M 8/0289: Means for holding the electrolyte (solid polymer electrolytes H01M8/1018) - Y02E 60/50: Fuel cells - Y10T 29/49108: Electric battery cell making - H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY - C25B: ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR (anodic or cathodic protection C23F13/00; single-crystal growth C30B) - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract Protecting a membrane and electrode assembly in an electrochemical cell having one or more electrocatalysts in intimate contact with the membrane during storage or shipment of the cell. The membrane may be provided in either the non-proton form of a dry or hydrated cation exchange membrane, such as an alkali metal cation form or an ammonium cation form; the wet or dry precursor form of a cation exchange membrane, such as the non-ionically conducting sulfonyl-fluoride polymer membrane; or the dry proton form of a cation exchange membrane. These membrane surfaces are not acidic under open circuit conditions experienced during storage or shipment of the cell. Since some electrocatalysts are degraded during contact with the acidic surface of a hydrated membrane, the non-acidic surface of the membrane protects these electrocatalysts. The method may be used on newly assembled electrochemical cells, on cells being taken out of service, and on membrane and electrode assemblies. ## Claims ### Claim 1 A method, comprising: providing a membrane and electrode assembly having one or more electrocatalysts in intimate contact with a cation exchange membrane in an alkali metal cation form during a period without an electrical current passing through the membrane and electrode assembly. ### Claim 2 (depends on 1) The method of claim 1, wherein at least one of the one or more electrocatalysts has an electrocatalytic activity that diminishes when placed in contact with a hydrated proton form of the cation exchange membrane in the absence of an electrical current flowing through the cell. ### Claim 3 (depends on 2) The method of claim 2, wherein the electrocatalytic activity diminishes by a process selected from degradation, dissolution, corrosion, or a combination thereof. ### Claim 4 (depends on 1) The method of claim 1, wherein the one or more electrocatalysts includes lead dioxide. ### Claim 5 (depends on 1) The method of claim 1, further comprising: placing the membrane and electrode assembly into an electrochemical cell or an electrochemical cell stack. ### Claim 6 (depends on 5) The method of claim 5, wherein the electrochemical cell or electrochemical cell stack includes a fuel cell or an electrolytic cell. ### Claim 7 (depends on 1) The method of claim 1, wherein the cation exchange membrane is hydrated. ### Claim 8 (depends on 1) The method of claim 1, wherein the cation exchange membrane is dry. ### Claim 9 (depends on 1) The method of claim 1, further comprising: supplying the membrane and electrode assembly with reactants; and providing an electrical current through the membrane and electrode assembly to liberate protons and convert the cation exchange membrane from the alkali metal cation form to an acidic proton form. ### Claim 10 (depends on 1) The method of claim 1, further comprising: placing the membrane and electrode assembly into an electrochemical cell or an electrochemical cell stack. ### Claim 11 (depends on 10) The method of claim 10, wherein the cation exchange membrane is wet during the placing of the membrane and electrode assembly into the electrochemical cell or the electrochemical cell stack. ### Claim 12 (depends on 10) The method of claim 10, wherein the cation exchange membrane is dry during the placing of the membrane and electrode assembly into the electrochemical cell or the electrochemical cell stack. ### Claim 13 A method, comprising: providing a membrane and electrode assembly having one or more electrocatalysts in intimate contact with a sulfonyl fluoride form of a precursor to a cation exchange membrane during a period without an electrical current passing through the membrane and electrode assembly. ### Claim 14 (depends on 13) The method of claim 13, wherein at least one of the one or more electrocatalysts has an electrocatalytic activity that diminishes when placed in contact with a hydrated proton form of the cation exchange membrane in the absence of an electrical current flowing through the cell. ### Claim 15 (depends on 14) The method of claim 14, wherein the electrocatalytic activity diminishes by a process selected from degradation, dissolution, corrosion, or a combination thereof. ### Claim 16 (depends on 13) The method of claim 13, wherein the one or more electrocatalysts includes lead dioxide. ### Claim 17 (depends on 13) The method of claim 13, further comprising: placing the membrane and electrode assembly into an electrochemical cell or an electrochemical cell stack. ### Claim 18 (depends on 17) The method of claim 17, wherein the electrochemical cell or electrochemical cell stack includes a fuel cell or an electrolytic cell. ### Claim 19 (depends on 13) The method of claim 13, further comprising: converting the cation exchange membrane from the sulfonyl-fluoride form to an alkali metal cation form. ### Claim 20 (depends on 19) The method of claim 19, wherein the step of converting includes contacting the cation exchange membrane with an alkali metal hydroxide solution. ### Claim 21 (depends on 20) The method of claim 20, wherein the alkali metal hydroxide is selected from NaOH, KOH, LiOH, RbOH, CsOH, FrOH, and combinations thereof. ### Claim 22 (depends on 20) The method of claim 20, wherein the alkali metal hydroxide solution has a concentration of between about 0.1M and about 10M. ### Claim 23 (depends on 20) The method of claim 20, wherein the alkali metal hydroxide solution has a concentration of between about 0.5M and about 5M. ### Claim 24 (depends on 20) The method of claim 20, wherein the alkali metal hydroxide solution has a concentration of between about 0.75M and about 3M. ### Claim 25 (depends on 20) The method of claim 20, wherein the alkali metal hydroxide solution contacts the proton exchange membrane for between about 0.25 hours and about 24 hours. ### Claim 26 (depends on 20) The method of claim 20, wherein the alkali metal hydroxide solution contacts the proton exchange membrane for between about 0.5 hours and about 12 hours. ### Claim 27 (depends on 20) The method of claim 20, wherein the alkali metal hydroxide solution contacts the proton exchange membrane for between about 1 hour and about 6 hours. ### Claim 28 (depends on 19) The method of claim 19, further comprising: providing the cation exchange membrane in a wet state. ### Claim 29 (depends on 19) The method of claim 19, further comprising: providing the cation exchange membrane in a dry state. ### Claim 30 (depends on 19) The method of claim 19, further comprising: assembling the membrane and electrode assembly into an electrochemical cell or an electrochemical cell stack. ### Claim 31 (depends on 30) The method of claim 30, wherein the cation exchange membrane is wet during the assembling of the membrane and electrode assembly into the electrochemical cell or the electrochemical cell stack. ### Claim 32 (depends on 30) The method of claim 30, wherein the cation exchange membrane is dry during the assembling of the membrane and electrode assembly into the electrochemical cell or the electrochemical cell stack. ### Claim 33 (depends on 19) The method of claim 19, further comprising: supplying the membrane and electrode assembly with reactants; and providing an electrical current through the membrane and electrode assembly to liberate protons and convert the cation exchange membrane from the alkali metal cation form to an acidic proton form. ### Claim 34 (depends on 33) The method of claim 33, wherein the steps of supplying reactants and providing an electrical current are performed simultaneously or nearly simultaneously. ### Claim 35 A method, comprising: passing electrical current through a membrane and electrode assembly having one or more electrocatalysts in intimate contact with a cation exchange membrane in a hydrated proton form; and then supplying an alkali metal hydroxide solution to a membrane and electrode assembly under an electrical potential; and then removing an electrical potential from across the membrane and electrode assembly, wherein the proton exchange membrane is converted from the hydrated proton form to the alkali metal cation form. ### Claim 36 (depends on 35) The method of claim 35, further comprising: removing the alkali metal hydroxide solution from the electrochemical cell. ### Claim 37 (depends on 35) The method of claim 35, further comprising: supplying the electrochemical cell with reactants; and restoring the electrical potential across the electrochemical cell to liberate protons and convert the proton exchange membrane from the alkali metal cation form back to the acidic form. ### Claim 38 (depends on 35) The method of claim 35, wherein the alkali metal hydroxide is selected from NaOH, KOH, LiOH, RbOH, CsOH, FrOH and combinations thereof. ### Claim 39 (depends on 38) The method of claim 38, wherein the alkali metal hydroxide solution has a concentration of between about 0.1M and about 10M. ### Claim 40 (depends on 38) The method of claim 38, wherein the alkali metal hydroxide solution has a concentration of between about 0.5M and about 5M. ### Claim 41 (depends on 38) The method of claim 38, wherein the alkali metal hydroxide solution has a concentration of between about 0.75M and about 3M. ### Claim 42 (depends on 34) The method of claim 34, wherein the step of converting the proton exchange membrane further comprises: contacting the proton exchange membrane with the alkali metal hydroxide solution for a period between about 0.25 hour and about 24 hours. ### Claim 43 (depends on 42) The method of claim 42, wherein the period is between about 0.5 hours and about 12 hours. ### Claim 44 (depends on 42) The method of claim 42, wherein the period is between about 1 hour and about 6 hours.