# US 8,568,939 B2 · Fuel cell including fluid-permeable members of differing thermal resistances with respect to an electrolytic membrane > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,568,939 B2 - Document ID: US8568939B2 - Status: Granted - Kind: B2 - Application number: 12/438,625 - Filed: 2007-08-22 - Published: 2010-10-07 - Granted: 2013-10-29 - Earliest claimed: 2006-08-24 - Assignees: Toyota Jidosha Kabushiki Kaisha - Applicants: Osamu Yumita; Shinji Jomori; Yoshihumi Oota - Inventors: Osamu Yumita; Shinji Jomori; Yoshihumi Oota - Web page: https://patentgrep.com/patent/US8568939B2 ## CPC - H01M 8/04007: related to heat exchange - H01M 8/0232: Metals or alloys - H01M 8/0234: Carbonaceous material - H01M 8/0239: Organic resins; Organic polymers - H01M 8/0245: in the form of layered or coated products - 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 includes a membrane-electrode assembly, passageways provided on both sides of the membrane-electrode assembly, and fluid-permeable members provided between the membrane-electrode assembly and the passageways. Thermal resistance of the fluid-permeable member on an anode side is lower than that of the fluid-permeable member on a cathode side. In this case, heat flux at the anode side fluid-permeable member is increased, and heat flux at the cathode side fluid-permeable member is decreased. ## Claims ### Claim 1 A fuel cell comprising: a membrane-electrode assembly including an anode, a cathode, and an electrolytic membrane; passageways provided on both sides of the membrane-electrode assembly; and fluid-permeable members provided between the membrane-electrode assembly and the passageways, wherein a thermal resistance of a fluid-permeable member on an anode side is lower than a thermal resistance of a fluid-permeable member on a cathode side, based on a condition of at least one of a material, a material quality, and a thickness of the fluid-permeable members, wherein one of the fluid-permeable member on the anode side and the fluid-permeable member on the cathode side is a first fluid-permeable member and includes a first water-repellant layer disposed on the membrane-electrode assembly and a first gas diffusion layer adjacent to and between the first water-repellant layer and one of the passageways, the first water-repellant layer being made of polytetrafluoroethylene (PTFE) including carbon, the first gas diffusion layer being made of a carbon paper or a carbon cloth, wherein a thermal resistance of the electrolytic membrane is smaller than a thermal resistance differential between the fluid-permeable members, based on a condition of at least one of a material, a material quality, and a thickness of the fluid-permeable members and the electrolytic membrane. ### Claim 2 (depends on 1) The fuel cell as claimed in claim 1 wherein the other of the fluid-permeable member on the anode side and the fluid-permeable member on the cathode side is a second fluid-permeable member and includes a second gas diffusion layer, wherein a thickness of one of the first and second gas diffusion layers is smaller than a thickness of the other of the first and second gas diffusion layers. ### Claim 3 (depends on 1) The fuel cell as claimed in claim 1 wherein the other of the fluid-permeable member on the anode side and the fluid-permeable member on the cathode side is a second fluid-permeable member and includes a second gas diffusion layer made of one of a carbon paper and a carbon cloth, wherein one of the first and second gas diffusion layers is made of a material having a thermal resistivity lower than a thermal resistivity of a material composing the other of the first and second gas diffusion layers. ### Claim 4 (depends on 1) The fuel cell as claimed in claim 1 wherein the first gas diffusion layer is the only gas diffusion layer and is provided between the cathode of the membrane-electrode assembly and the one passageway, wherein the one passageway is on the cathode side. ### Claim 5 (depends on 1) The fuel cell as claimed in claim 1 wherein the other of the fluid-permeable member on the anode side and the fluid-permeable member on the cathode side is a second fluid-permeable member and includes a second water-repellent layer made of polytetrafluoroethylene (PTFE) including carbon disposed on the membrane-electrode assembly. ### Claim 6 (depends on 5) The fuel cell as claimed in claim 5 wherein a thickness of the one of the first and second water-repellent layers provided on the anode side is smaller than a thickness of the other of the first and second water-repellent layers provided on the cathode side. ### Claim 7 (depends on 5) The fuel cell as claimed in claim 5 wherein the one of the first and second water-repellent layers provided on the anode side is made of a material having a thermal resistivity lower than a thermal resistivity of a material composing the other of the first and second water-repellent layers provided on the cathode side. ### Claim 8 (depends on 5) The fuel cell as claimed in claim 5 wherein the first gas diffusion layer is the only gas diffusion layer and is provided between a cathode of the membrane-electrode assembly and the one passageway, wherein the one passageway is on the cathode side. ### Claim 9 (depends on 1) The fuel cell as claimed in claim 1 wherein the first gas diffusion layer is made of a material having an elasticity higher than an elasticity of at least one of the passageways. ### Claim 10 (depends on 1) The fuel cell as claimed in claim 1 wherein at least one of the passageways is a three-dimensional mesh structure passageway. ### Claim 11 (depends on 10) The fuel cell as claimed in claim 10 wherein the three-dimensional mesh structure passageway is made of a porous body. ### Claim 12 (depends on 11) The fuel cell as claimed in claim 11 wherein the porous body is a metal porous body. ### Claim 13 (depends on 10) The fuel cell as claimed in claim 10 further comprising a separator provided on a side of the three-dimensional mesh structure passageway opposite of a membrane-electrode assembly side of the three-dimensional mesh structure passageway. ### Claim 14 (depends on 13) The fuel cell as claimed in claim 13 wherein a contacting face between the separator and the three-dimensional mesh structure passageway is flat. ### Claim 15 (depends on 1) The fuel cell as claimed in claim 1 wherein: the passageways are three-dimensional mesh structure passageways, the fluid-permeable member on the cathode side includes the first water-repellant member and first gas diffusion layer, the fluid-permeable member on the anode side includes a second water-repellant member, the first water-repellent layer, the first gas diffusion layer, the one of the passageways, and a first separator are laminated on the membrane-electrode assembly on a cathode side in that order from the cathode; and the second water-repellent layer, the other of the passageways, and a second separator, are laminated on the membrane-electrode assembly on an anode side in that order from the anode. ### Claim 16 (depends on 1) The fuel cell as claimed in claim 1 wherein the fluid-permeable member on the cathode side includes the first gas diffusion layer and the fluid-permeable member on the anode side includes a second gas diffusion layer, and wherein a thickness of the first gas diffusion layer is equal to a thickness of the second gas diffusion layer. ### Claim 17 (depends on 1) The fuel cell as claimed in claim 1 wherein the fluid-permeable member on the cathode side includes the first gas diffusion layer and the fluid-permeable member on the anode side includes a second gas diffusion layer, and wherein the first and second gas diffusion layers are made from one material, and wherein a fiber diameter of the one material forming the first gas diffusion layer is smaller than a fiber diameter of the one material forming the second gas diffusion layer. ### Claim 18 (depends on 5) The fuel cell as claimed in claim 5 wherein the other of the fluid-permeable members includes a second gas diffusion layer, and wherein a thickness of one of the first and second gas diffusion layers is smaller than a thickness of the other of the first and second gas diffusion layers. ### Claim 19 (depends on 5) The fuel cell as claimed in claim 5 wherein the fluid-permeable member on the cathode side includes the first gas diffusion layer and the fluid-permeable member on the anode side includes a second gas diffusion layer, and wherein a thickness of the first gas diffusion layer is equal to a thickness of the second gas diffusion layer.