GB1179777A - Electrochemical Cells Comprising Air-Depolarised Electrodes - Google Patents

Abstract

1,179,777. Air-depolarized cell. SOC. DES ACCUMULATEURS FIXES ET DE TRACTION. 5 July, 1967 [5 July, 1966], No. 31058/67. Heading H1B. An air-depolarized cell in which the negative electrode may be regenerated comprises a case containing: (a) an electrolyte, (b) a negative electrode, (c) a hydrophobic positive electrode, depolarized by air, not more than 0À5 mm. from the negative electrode and protruding above the electrolyte surface and (e) another positive electrode. Electrode (c) is used during discharge of the cell and electrode (d) is used during regeneration of the negative electrode. The case may have a hermetically sealed lid fitted with an air inlet, a gas escape valve and terminals joined to the three electrodes the air being supplied by a micropump driven by power from the cell. The negative electrode may beless than 1mm. thick and may be a sintered Ni support containing cadmium hydroxide or powerediron or cadmium. Thepowdered iron may be mixed with microscopic crystals of copper of acicular, deutritic, or arborescent shape and the powdered cadmium may be mixed with Ni or Fe powder and compressed. The active material may be retained in a pocket of perforated steel sheet. The gas electrode may be a metal gauze covered with particles of silver plated carbon or a mixture of particles of carbon, silver and or nickel bound with polystyrene. The regeneration electrode may be a perforated nickel plated steel sheet. The electrodes may be separated by nylon felts 0À15-0À3 mm. thick. A multicell battery may comprise intercell partitions of plastics material, each cell having a gas electrode on one side and a regeneration electrode on the other, each cell being completed by a negative electrode between the two positive ones. The cells may be joined in parallel or in series the connections being arranged to facilitate switching from a discharging circuit to a regeneration circuit. The cells may be permanently wired as shown by the continuous and broken lines in Fig. 6, to a switch 13 in which the connectors are rotatable through 90 degrees from the discharging position shown to a regeneration position. Alternatively the intercell connectors may be joined by insulating material into a single bar movable between discharging and regeneration positions (Fig. 7).