FILTER-PRESS TYPE FUEL CELL BATTERY WITH IMPROVED DIAPHRAGM MEMBERS

1302814 Fuel cell batteries SIEMENS AG 28 May 1971 [29 May 1970] 18194/71 Heading H1B A fuel cell battery, Fig. 1 comprises cells 1 ... 5 separated from each other by nickel sheets 6, the end cells 1, 5 having nickel sheets 9 connected to lead-off conductors 10. Each cell has an electrolyte chamber 11 and a gas chamber 12 separated from each other by an asbestos diaphragm 13. The anode 14 in chamber 11 comprises a nickel gauge coated with platinum or Raney nickel as catalyst and makes contact through a nickel gauge 15 with a sheet 6 or 9. The cathode 17 in chamber 12 comprises pulverous Raney silver, preferably bound by a hydrophilic plastics latex, or carbon powder activated with silver. A nickel gauge 18 maintains contact being the cathode 17 and a sheet 6 or 9. The chamber 11 is supplied with a mixture of fuel and electrolyte consisting of hydrazine dissolved in KOH and the chamber 12 is supplied with oxygen. In alternative arrangements the fuel may be methanol or the electrolyte may be acid. Sealing of the periphery of the cells 1 ... 5 is obtained by the asbestos diaphragms 13 and to this end their peripheral portions 21 are given a greater thickness by providing on either side asbestos gaskets 20, 22. The portions 21 of the diaphragms 13 are impregnated with an electrolyte-resistant synthetic resin, e.g. epoxy resin and the asbestos forming the gaskets 20, 22 is filled with a relatively soft electolyte-resistant plastics material, e.g. PTFE or PVC The portions 21 are bonded to the gaskets 20, 22 by curing the epoxy resin at elevated temperature. The several components are clamped together to form the battery by screw bolts 7. The reactants are supplied to the cells via aligned passages formed in the peripheral portions 21 the gaksets 20, 22, and sheets 6, 9. Fig. 3 shows another embodiment in which the asbestos sealing arrangement is applied to a battery in which the reactants are hydrogen and oxygen. The Fig. shows two intermediate cells 41, 42 of a stack, the stack ends being omitted. In this embodiment each cell comprises a gas chmber 43 for the hydrogen, a gas chamber 44 for the oxygen and a chamber 45 for the KOH electrolyte, these chambers being separated from each other by asbestos diaphragms 46, 47. The anode 49 consists of Raney nickel powder optionally containing a binder and the chamber 45 contains a spacer gauge 53 of nickel or plastics material. The cathode 51 is similar to that of Fig. 1. To obtain the sealing of the cells, the peripher