| 摘要 |
1,272,109. Fuel cell electrodes. VARTA A.G. 28 July, 1969 [22 Aug., 1968], No. 37781/69. Heading H1B. A fuel cell comprises a fuel gas electrode, an oxidant gas electrode and an electrolyte, at least one of the gas electrodes comprising a porous layer of coherent metal particles in contact with the electrolyte and a gas-permeable layer of plastics-bonded carbon powder stuck to the metal layer and in contact with the gas. The metal layer may be of nickel. The carbon powder may be activated carbon, optionally carrying a noble metal catalyst, e.g. palladium. The plastics binder may be polythene dissolved in toluene, or P.T.F.E. emulsion optionally supplemented with polyvinyl alcohol solution. The plastics-bonded carbon layer may be sprayed or cast on to the metal layer, but in either case measures should be taken to ensure that no hydrophobic material remains on the electrolyte side of the metal plate. In Example 1, any polyethylene on the electrolyte side is washed off with a mixture of isopropanol and potassium hydroxide solution before the electrode is used as a hydrogen or oxygen electrode. In Example 2, plastics material is prevented from sticking to the electrolyte side by precoating it with carboxymethyl cellulose which is later washed off before the electrode is used as an air electrode. In Example 3, the carbon layer is applied as a paste including NH 4 OH and ethylene glycol and the electrode is used as an air electrode against hydrazine. |
