Elektrischer Akkumulator

1,234,414. Electric cell. CONSIGLIO NAZIONALE DELLE RICERCHE. 12 Aug., 1968 [2 Sept., 1967; 2 May, 1968], No. 38499/68. Heading H1B. An electric cell contains a zinc anode, an aqueous electrolyte of a zinc halide, a cathode comprising an inert electrode, e.g. of graphite, supporting elemental halogen, and an organic solvent which is immiscible with water and which is capable of retaining the free halogen liberated during the charging process, the halogen and halide being derived from the same element, preferably iodine or bromine. The electrolyte preferably contains a soluble exchange salt which has a higher specific conductivity than the zinc halide and which -forms a precipitate of a zinc salt and another metal halide by exchanging with the zinc halide. The precipitate and organic solvent are preferably electrical insulators. The cells may be mounted in a common box 1 and are separated by walls 11 which hold plates 3 one surface of which is covered with graphite and constitutes the inert electrode 4 of the adjacent cell. The plates are spaced to allow the passage of electrolyte therebetween. In order to prevent corrosion when not in use the battery may be inverted so that the electrolyte enters space 7 above the electrodes, Fig. 2. Alternatively, a receptacle which can contain all the electrolyte can be provided under each cell and contains an inflatable plastics pocket, so that on inflation all the electrolyte is forced upwards into contact with the electrodes, and can be agitated by pulsating the pocket. Alternatively a thermal convection current can be set up in the electrolyte by means of electrical resistance heaters set up in a series of tubes on the side of box 1. In a zinc-bromine battery using an exchange salt, Fig. 6, each cell is provided with a discharge conduit 71 which is connected to a common receptacle 8 which contains an organic solvent 91 for retaining the halogen, the precipitate 101 resulting during discharge from the reaction between the exchange salt and the zinc bromide, and electrolyte 2. A suction tube 5 attached to receptacle '8 'carries electrolyte to pump 61 which distributes it by means of discharge tubes 12 to each cell.