# US 10,312,529 B2 · 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 10,312,529 B2 - Document ID: US10312529B2 - Status: Granted - Kind: B2 - Application number: 15/766,101 - Filed: 2015-10-06 - Published: 2018-10-04 - Granted: 2019-06-04 - Earliest claimed: 2015-10-06 - Assignees: Nissan Motor Co., Ltd. - Applicants: Nissan Motor Co., Ltd. - Inventors: Takanori Oku - Web page: https://patentgrep.com/patent/US10312529B2 ## CPC - H01M 8/0297: Arrangements for joining electrodes, reservoir layers, heat exchange units or bipolar separators to each other (H01M8/0271 takes precedence) - H01M 8/02: Details (electrodes H01M4/86 - H01M4/98) - H01M 8/0206: Metals or alloys - H01M 8/0247: characterised by the form (characterised by a channel configuration H01M8/0258) - H01M 8/0258: characterised by the configuration of channels, e.g. by the flow field of the reactant or coolant - H01M 8/1004: characterised by membrane-electrode assemblies [MEA] (H01M8/12 takes precedence) - H01M 8/24: Grouping of fuel cells, e.g. stacking of fuel cells - H01M 8/0202: Collectors; Separators, e.g. bipolar separators; Interconnectors - H01M 8/242: comprising framed electrodes or intermediary frame-like gaskets (H01M8/2425, H01M8/244 take precedence) - H01M 2008/1095: {Fuel cells with polymeric 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 A fuel cell stack is constituted by stacking fuel cells including a membrane electrode assembly constituted by sandwiching an electrolyte membrane with a pair of electrodes and a pair of separators that have flow passages through which gas to be supplied to the membrane electrode assembly flows, the pair of separators being arranged across the membrane electrode assembly. The fuel cell stack includes a welded portion where the separators adjacent to one another in a stacking direction of the fuel cell are welded. The separator in the stacking direction at the welded portion has a height lower than a height of the separator other than the welded portion. ## Claims ### Claim 1 A fuel cell stack comprising: a plurality of fuel cells, each of the fuel cells including a membrane electrode assembly sandwiched between a pair of separators that have flow passages through which gas to be supplied to the membrane electrode assembly flows, the membrane electrode assembly comprising an electrolyte membrane sandwiched between a pair of electrodes, the pair of separators being arranged across the membrane electrode assembly such that the pair of separators contact the membrane electrode assembly on opposing sides thereof, and each separator of the pair of separators comprising bottom portions in contact with the membrane electrode assembly and protrusions that protrude from the bottom portions in a stacking direction of the fuel cell; and at least one welded portion where separators adjacent to one another in the stacking direction are welded, the at least one welded portion being formed between at least one pair of protrusions adjacent to one another in the stacking direction, wherein a height, in the stacking direction, of a protrusion of a given separator on which a welded portion is formed is less than a height, in the stacking direction, of a protrusion of the given separator on which a welded portion is not formed. ### Claim 2 (depends on 1) The fuel cell stack according to claim 1, wherein: the bottom portions and the protrusions are sequentially arranged in one direction on a surface of each separator. ### Claim 3 (depends on 2) The fuel cell stack according to claim 2, wherein: the protrusion on which the welded portion is formed has a sidewall part comprising a deformed portion configured to elastically deform, and the deformed portion is preliminarily elastically deformed such that the height of the protrusion on which the welded portion is formed is less than the height of the protrusion on which the welded portion is not formed. ### Claim 4 (depends on 2) The fuel cell stack according to claim 2, wherein a difference between the height of the protrusion on which the welded portion is formed and the height of the protrusion on which the welded portion is not formed is equal to a height of the welded portion. ### Claim 5 (depends on 2) The fuel cell stack according to claim 2, wherein the welded portion includes a line welded portion formed along an extending direction of the flow. ### Claim 6 (depends on 2) The fuel cell stack according to claim 2, wherein the at least one welded portion comprises a plurality of spot welded portions formed at predetermined distance intervals in an extending direction of the flow passages. ### Claim 7 (depends on 2) The fuel cell stack according to claim 2, wherein: the at least one welded portion comprises a plurality of welded portions formed on different protrusions in an arranging direction of the flow passages, and at least one protrusion on which a welded portion is not formed is provided between protrusions on which the welded portions are formed in the arranging direction of the flow passages. ### Claim 8 (depends on 1) The fuel cell stack according to claim 1, wherein the pair of separators comprises a first separator and a second separator each having a welded portion formed thereon, and the welded portion formed on the first separator and the welded portion formed on the second separator are offset at least in one direction of an extending direction of the flow passages or an arranging direction of the flow passages. ### Claim 9 (depends on 1) The fuel cell stack according to claim 1, wherein the at least one welded portion comprises a plurality of welded portions, and all the welded portions included in the fuel cell stack are positioned at different positions when viewed from the stacking direction. ### Claim 10 (depends on 1) The fuel cell stack according to claim 1, wherein the at least one welded portion comprises a plurality of welded portions, and all the welded portions included in the fuel cell stack are positioned offset from one another when viewed from the stacking direction.