| 摘要 |
1286173 Hybrid air-secondary cells COMPAGNIE GENERALE D'ELECTRICITE 2 Oct1970 [6 Oct1969] 47070/70 Heading H1B A rechargeable cell comprises an air electrode 1, e.g. a sintered nickel support impregnated with a catalyst, a metallic electrode 2, e.g. of iron or cadmium, and an alkaline electrolyte, e.g. potassium hydroxide, in which the metal of electrode 2 is insoluble. In use, the electrolyte needs to be decarbonated from carbon dioxide adsorbed from the air. To this end, the electrolyte compartment is divided into two sections 4, 5 by a cation exchange membrane 3. As shown, the membrane is disposed between the electrodes 1, 2 but in a modification (not shown) the membrane is disposed between the electrode 2 and a counter electrode serving as the decarbonating electrode. Fig. 1 shows the discharge reaction in which the electrolyte content increases in compartment 4 and decreases in compartment 5; also, the electrolyte in compartment 4 becomes carbonated and KOH forms a layer on electrode 2. Before the dilution of compartment 5 is complete the discharge is stopped and the cell is recharged. The charge current causes the electrolyte content of the two sections 4, 5 to become equal but after this state is reached the charge current is maintained so that the pH value of the electrolyte in compartment 4 is lowered to about 7 or 8 and the unwanted carbon dioxide is liberated. At the conclusion of this treatment the compartment 4 contains pure water and before the cell can be used this electrolyte must be made conductive. This may be achieved by not using the cell for a short time to permit K<SP>+</SP> ions to enter the compartment 4 from compartment 5; alternatively, to permit immediate use of the cell, a current is passed through the cell for a very short time in the discharge direction. |
