# US 2023/0056961 A1 · Fuel cell stack > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2023/0056961 A1 - Document ID: US20230056961A1 - Status: Published application - Kind: A1 - Application number: 17/789,868 - Filed: 2020-11-30 - Published: 2023-02-23 - Earliest claimed: 2019-12-30 - Assignees: Robert Bosch GmbH - Applicants: Robert Bosch GmbH - Inventors: Arnold Gente; Eberhard Maier - Web page: https://patentgrep.com/patent/US20230056961A1 ## CPC - H01M 8/0258: characterised by the configuration of channels, e.g. by the flow field of the reactant or coolant - H01M 8/0267: having heating or cooling means, e.g. heaters or coolant flow channels - H01M 8/0271: Sealing or supporting means around electrodes, matrices or membranes - H01M 8/0276: Sealing means characterised by their form (H01M8/0273 takes precedence) - H01M 8/1004: characterised by membrane-electrode assemblies [MEA] (H01M8/12 takes precedence) - 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 invention relates to a fuel cell stack (100) having at least one fuel cell (101) which has a membrane (CCM) for separating an anode side (A) of the fuel cell (101) from a cathode side (K) of the fuel cell (101), an anode-side gas diffusion layer (GDLA), a cathode-side gas diffusion layer (GDLK) and a bipolar plate (BPP) for separating the fuel cell (101) from an adjacent fuel cell (101) or a housing. According to the invention, the membrane (CCM) protrudes beyond the anode-side gas diffusion layer (GDLA) and the cathode-side gas diffusion layer (GDLK) in an edge region (R) located outside an active area (AF) of the membrane (CCM), and the membrane (CCM) has a centering dam (10) in the edge region (R) of the anode side (A) or of the cathode side (K). ## Claims ### Claim 1 A fuel cell stack (100), comprising: at least one fuel cell (101), which comprises a membrane (CCM) for separating an anode side (A) of the fuel cell (101) from a cathode side (K) of the fuel cell (101), an anode-side gas diffusion layer (GDLA), a cathode-side gas diffusion layer (GDLK), and a bipolar plate (BPP) for separating the fuel cell (101) from an adjacent fuel cell (101) or from a housing, wherein the membrane (CCM) protrudes beyond the anode-side gas diffusion layer (GDLA) and the cathode-side gas diffusion layer (GDLK) in an edge region (R) which is located outside an active area (AF) of the membrane (CCM), and wherein the membrane (CCM) comprises a centering dam (10) in the edge region (R) of the anode side (A) or of the cathode side (K). ### Claim 2 (depends on 1) The fuel cell stack (100) as claimed in claim 1, wherein the centering dam (10) is secured cohesively on the membrane (CCM), and/or wherein the centering dam (10) is printed, vulcanized or injection-molded on the membrane (CCM). ### Claim 3 (depends on 1) The fuel cell stack (100) as claimed in claim 1, wherein in the edge region (R) the membrane (CCM) is provided with an elastic sealing layer (SG), with the centering dam (10) being secured cohesively on the sealing layer (SG). ### Claim 4 (depends on 3) The fuel cell stack (100) as claimed in claim 3, wherein the centering dam (10) is printed, vulcanized or injection-molded on the sealing layer (SG), or wherein the centering dam (10) is produced by folding of a sealing layer (SG). ### Claim 5 (depends on 1) The fuel cell stack (100) as claimed in claim 1, wherein the centering dam (10) has a height which is less than a height of a coolant channel (KK) of the bipolar plate (BPP), and/or wherein the centering dam (10) has a height which is 0.5 to 0.99 times the height of a coolant channel (KK) of the bipolar plate (BPP). ### Claim 6 (depends on 1) The fuel cell stack (100) as claimed in claim 1, wherein the bipolar plate (BPP) comprises a closed coolant channel (GK) in the edge region (R) of the membrane (CCM). ### Claim 7 (depends on 6) The fuel cell stack (100) as claimed in claim 6, wherein the closed coolant channel (GK) is produced by bending of two plates (1, 2) of the bipolar plate (BPP) in the same direction, and/or wherein the closed coolant channel (GK) is aligned at an angle between 0° and 90° to the membrane (CCM). ### Claim 8 (depends on 1) The fuel cell stack (100) as claimed in claim 1, wherein the centering dam (10) is matched to a geometry of the bipolar plate (BPP) in the edge region (R) of the membrane (CCM) in order to center the membrane (CCM) in the fuel cell stack (100) and in order to seal the at least one fuel cell (101). ### Claim 9 (depends on 1) The fuel cell stack (100) as claimed in claim 1, wherein the centering dam (10) is configured in the form of a trapezium. ### Claim 10 (depends on 9) The fuel cell stack (100) as claimed in claim 9, wherein the trapezium has a leg which is aligned parallel to the closed coolant channel (GK) of the bipolar plate (BPP) and lies sealingly against the closed coolant channel (GK) of the bipolar plate (BPP). ### Claim 11 (depends on 2) The fuel cell stack (100) as claimed in claim 2, wherein in the edge region (R) the membrane (CCM) is provided with an elastic sealing layer (SG), with the centering dam (10) being secured cohesively on the sealing layer (SG). ### Claim 12 (depends on 11) The fuel cell stack (100) as claimed in claim 11, wherein the centering dam (10) is printed, vulcanized or injection-molded on the sealing layer (SG), or wherein the centering dam (10) is produced by folding of a sealing layer (SG). ### Claim 13 (depends on 12) The fuel cell stack (100) as claimed in claim 12, wherein the centering dam (10) has a height which is less than a height of a coolant channel (KK) of the bipolar plate (BPP), and/or wherein the centering dam (10) has a height which is 0.7 to 0.9 times the height of a coolant channel (KK) of the bipolar plate (BPP). ### Claim 14 (depends on 13) The fuel cell stack (100) as claimed in claim 13, wherein the bipolar plate (BPP) comprises a closed coolant channel (GK) in the edge region (R) of the membrane (CCM). ### Claim 15 (depends on 14) The fuel cell stack (100) as claimed in claim 14, wherein the closed coolant channel (GK) is produced by bending of two plates (1, 2) of the bipolar plate (BPP) in the same direction, and/or wherein the closed coolant channel (GK) is aligned at an angle between 30° and 60° to the membrane (CCM). ### Claim 16 (depends on 14) The fuel cell stack (100) as claimed in claim 14, wherein the closed coolant channel (GK) is produced by bending of two plates (1, 2) of the bipolar plate (BPP) in the same direction, and/or wherein the closed coolant channel (GK) is aligned at an angle of 45° to the membrane (CCM). ### Claim 17 (depends on 16) The fuel cell stack (100) as claimed in claim 16, wherein the centering dam (10) is matched to a geometry of the bipolar plate (BPP) in the edge region (R) of the membrane (CCM) in order to center the membrane (CCM) in the fuel cell stack (100) and in order to seal the at least one fuel cell (101). ### Claim 18 (depends on 17) The fuel cell stack (100) as claimed in claim 17, wherein the centering dam (10) is configured in the form of a trapezium, with the base of the trapezium lying on the membrane (CCM) or on a sealing layer (SG) of the membrane (CCM). ### Claim 19 (depends on 18) The fuel cell stack (100) as claimed in claim 18, wherein the trapezium has a leg which is aligned parallel to the closed coolant channel (GK) of the bipolar plate (BPP) and lies sealingly against the closed coolant channel (GK) of the bipolar plate (BPP).