| 摘要 |
1,072,577. Fuel cells. UNION CARBIDE CORPORATION. May 29, 1964 [June 7, 1963], No. 22219/64. Heading H1B. A fuel cell electrode comprises .a porous conductive body having a first porous zone A, of a plurality of layers 11, 12, 13, which is electrochemically active and permeable to liquid electrolyte, and which extends inwardly from one surface of the body, each of said layers being more electrolyte-repellent and less electrochemically active than the next outer layer adjacent thereto, and an adjacent second porous zone B, which is a layer 14 entirely repellent to liquid electrolyte and gas-permeable and extends inwardly from another surface of the body. The electrolyte-repellent zone B is powdered graphite or an inactive metal powder, and this layer 14 has a metal mesh 15 as support or current collector. Activated carbon is used in layers 11, 12, 13, the particles increasing in size towards layer 14, and the layers increasing their content of thermoplastic binder similarly. The active zone A may be a mixture of powdered graphite and alumina, with an appropriate catalyst in the case of hydrogen electrodes, while zone B may be a sintered metal plaque. The electrode is alternatively treated with a wetproofing agent, which is removed selectively, leaving less in zone A and more in zone B by several methods such as vacuum distillation or leaching, to leave zone A active but with a gradient of electrolyte repellency increasing towards zone B, which is electrolyte-repellent. Zone A is pretreated with sodium carboxymethylcellulose to prevent adherence of the wetproofing agent thereto, and pre-cleaned by a vacuum heat treatment. |
