# US 12,119,528 B2 · Fuel cell stack assembly > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,119,528 B2 - Document ID: US12119528B2 - Status: Granted - Kind: B2 - Application number: 18/235,483 - Filed: 2023-08-18 - Published: 2024-02-08 - Granted: 2024-10-15 - Earliest claimed: 2017-06-26 - Assignees: Ceres Intellectual Property Company Limited - Applicants: Ceres Intellectual Property Company Limited - Inventors: Lee Rees; Stephen Phillip; Euan Freeman; Andrew Ballard; Tomasz Domanski; Eren Erturk; Alan Robertson - Web page: https://patentgrep.com/patent/US12119528B2 ## CPC - H01M 8/247: Arrangements for tightening a stack, for accommodation of a stack in a tank or for assembling different tanks - H01M 8/2475: Enclosures, casings or containers of fuel cell stacks - H01M 8/12: operating at high temperature, e.g. with stabilised ZrO2 electrolyte - H01M 8/2425: High-temperature cells with solid electrolytes - H01M 8/248: Means for compression of the fuel cell stacks - H01M 2008/1293: {Fuel cells with solid oxide electrolytes} - Y02E 60/50: Fuel cells - 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 present invention is concerned with an improved fuel cell stack assembly comprising a metal base plate on which is mounted at least one fuel cell stack and a metal end plate, each stack comprising at least one fuel cell stack layer that comprises at least one fuel cell and at least one electrically insulating compression gasket, wherein a skirt is attached to the base and end plates enclosing the stack and is under tension therebetween so as to maintain a compressive force through the stack, thereby obviating the need for tie-bars. ## Claims ### Claim 1 A metal supported solid oxide fuel cell stack assembly comprising: (i) a metal base plate; (ii) an at least one fuel cell stack mounted on the base plate; and (iii) a metal end plate; each at least one fuel cell stack arranged mounted between said base plate and said end plate, and comprising at least one fuel cell stack layer, each at least one fuel cell stack layer comprising at least one fuel cell and at least one electrically insulating compression gasket, characterised in that a skirt is attached to and between the base plate and the end plate to enclose the at least one fuel cell stack and is under tension to and between the base plate and the end plate to maintain a compressive force through the at least one fuel cell stack, and the solid oxide fuel cell stack assembly additionally comprising at least one expansion plate located between the base plate and the end plate, wherein the at least one expansion plate has a coefficient of thermal expansion greater than a coefficient of thermal expansion of the skirt, and the coefficient of thermal expansion of the skirt is greater than a coefficient of thermal expansion of the at least one fuel cell stack. ### Claim 2 (depends on 1) A metal supported solid oxide fuel cell stack assembly according to claim 1, wherein the at least one electrically insulating compression gasket has a coefficient of thermal expansion lower than the coefficient of thermal expansion of the skirt. ### Claim 3 (depends on 1) A metal supported solid oxide fuel cell stack assembly according to claim 1, wherein the at least one expansion plate is located between the end plate and the adjacent fuel cell stack layer. ### Claim 4 (depends on 1) A metal supported solid oxide fuel cell stack assembly according to claim 1, wherein the at least one expansion plate is located between the base plate and the adjacent fuel cell stack layer. ### Claim 5 (depends on 1) A metal supported solid oxide fuel cell stack assembly according to claim 1, wherein there is provided a plurality of fuel stack layers, and the at least one expansion plate is located between fuel stack layers. ### Claim 6 (depends on 1) A metal supported solid oxide fuel cell stack assembly according to claim 1, wherein the skirt is a metal skirt. ### Claim 7 (depends on 1) A metal supported solid oxide fuel cell stack assembly according to claim 1, wherein the skirt is attached to and between the base plate and the end plate by welding. ### Claim 8 (depends on 1) A metal supported solid oxide fuel cell stack assembly according to claim 1, wherein the skirt, at least one fuel cell stack, and at least one expansion plate expand along a longitudinal direction defined between the base plate and the end plate, wherein the expansion plate expands in the longitudinal direction by at least 50% of the expansion of the skirt in the longitudinal direction compared to the expansion of the at least one fuel cell stack in the longitudinal direction. ### Claim 9 A method of forming a metal supported solid oxide fuel cell stack assembly comprising the steps of: (a) assembling: (i) a metal base plate; (ii) an at least one fuel cell stack mounted on the base plate; (iii) an at least one expansion plate; and (iv) a metal end plate; each at least one expansion plate arranged between the base plate and the end plate, each at least one fuel cell stack arranged mounted between said base plate and said end plate, and comprising at least one fuel cell stack layer, each at least one fuel cell stack layer comprising at least one fuel cell and at least one electrically insulating compression gasket, (b) applying a compressive force through the at least one fuel cell stack using a compression means; (c) attaching a skirt to and between the base plate and the end plate to enclose the at least one fuel cell stack; and (d) removing the compression means so that the compressive load on the at least one fuel cell stack is maintained through tensile forces in the skirt; wherein the at least one expansion plate has a coefficient of thermal expansion greater than a coefficient of thermal expansion of the skirt, and the coefficient of thermal expansion of the skirt is greater than a coefficient of thermal expansion of the at least one fuel cell stack. ### Claim 10 (depends on 9) A method according to claim 9, wherein the at least one electrically insulating compression gasket has a coefficient of thermal expansion lower than the coefficient of thermal expansion of the skirt. ### Claim 11 (depends on 9) A method according to claim 9, wherein said skirt comprises a plurality of skirt sections. ### Claim 12 (depends on 9) A method according to claim 9, wherein the skirt is a metal skirt. ### Claim 13 (depends on 9) A method according to claim 9, wherein the skirt is attached to and between the base plate and the end plate by welding. ### Claim 14 (depends on 9) A method according to claim 9, wherein the at least one expansion plate is arranged between the end plate and the adjacent fuel cell stack layer. ### Claim 15 (depends on 9) A method according to claim 9, wherein the at least one expansion plate is arranged between the base plate and the adjacent fuel cell stack layer. ### Claim 16 (depends on 9) A method according to claim 9, wherein there is provided a plurality of fuel stack layers, and the at least one expansion plate is arranged between fuel stack layers. ### Claim 17 (depends on 9) A method according to claim 9, wherein the compressive force is applied through the at least one fuel cell stack using a compression means. ### Claim 18 (depends on 9) A method according to claim 9, wherein when the skirt, at least one fuel cell stack, and at least one expansion plate, expand along a longitudinal direction defined between the base plate and the end plate, the expansion plate expands in the longitudinal direction by at least 50% of the expansion of the skirt in the longitudinal direction compared to the expansion of the at least one fuel cell stack in the longitudinal direction.