Primary cells

摘要

1,056,622. Electric cells. MIFALEI YAM HAMELAH, B. M., and M. R. BLOCH. June 23, 1965 [June 24, 1964], No. 26660/65. Heading H1B. A primary cell has an aqueous solution of zinc halide or cadmium halide containing halogen, an electrode inert to the electrolyte, a zinc or cadmium electrode and a halogen permeable container containing a source of halogen in contact with the electrolyte for replenishing the halogen in the electrolyte. In the embodiment a zinc can 1 surrounds a layer of asbestos 3 soaked with zinc bromide solution and a perforated graphite electrode 2. The graphite electrode 2 shields the halogen permeable container 4 from the zinc electrode. The container is made of polythene or fluorinated hydrocarbons and contains zinc polybromide solution. A syphon 6 is provided connected between the electrolyte container and container 4 so that drop in pressure of the halogen supply is compensated. The shelf-life of the cell is improved by including a Mn+ + salt in the electrolyte. This forms a gel of Mn(OH) 4 which blocks the halogen container when on open circuit, but is dispersed when the circuit is closed. The halogen in the container may be in solution, adsorbed on a solid adsorbent, or in the form of a decomposable complex. The solution may be carbon tetrachloride, carbon tetrabromide, or other halogenated hydrocarbons. Adsorbents may be silica gel, active charcoal or tetramethyl ammonium chloride.