FURUKAWA BATTERY CO LTD RECHARGEABLE GALVANIC CELL WITH ZINC ANODE

摘要

1420710 Rechargeable zinc cell FURUKAWA ELECTRIC CO Ltd and FURUKAWA BATTERY CO Ltd 23 Jan 1974 [31 Jan 1973 6 Feb 1973 9 April 1973 (2)] 03047/74 Heading H1B A rechargeable cell comprises a zinc anode, a cathode, e.g. silver oxide, mercury oxide, manganese dioxide, nickel oxide or an oxygen diffusion electrode, and an aqueous alkaline electrolyte containing alkali metal zincate and a polycation in an amount sufficient to suppress formation of zinc dendrites during charge. A polycation is defined as a polymeric cation having two or more cation sites in the molecule. In the examples given the polycation is a quaternary ammonium salt. Examples are: poly-(N,N,NSP1/SP- NSP1/SP - tetramethyl - N - trimethylene - NSP1/SP - pentamethylene diammonium dibromide); poly- (oxyethyl - 1 - methylenetrimethyl ammonium chloride); poly - (N,N - dimethyldiallylammonium chloride); poly-(vinylbenzyltrimethylammonium chloride); poly - (N,N,NSP1/SP,N1 - tetra - methyl - N - ethylene - NSP1/SP - hexamethylene diammonium dibromide); poly-(N,N,NSP1/SP,NSP1/SP-tetramethyl - N - trimethylene - NSP1/SP - hexamethylene diammonium dibromide); N,N,NSP1/SP,NSP1/SP,NSP1/SP- hexamethyl trimethylene diammonium dibromide; poly-(oxyethyl-1-methylene-trimethyl ammonium chloride). The polycation may be prepared by quaternizing polyepihalohydrin or a copolymer of epihalohydrin and epoxide with a tertiary amine, e.g. trimethylamine. The polycation is present in the electrolyte in an amount 0À01-10% by weight of the electrolyte. The preferred alkaline electrolyte is sodium, potassium or lithium hydroxide in which zinc oxide is dissolved. In the instance where the cell has an oxygen diffusion positive electrode, an auxiliary charging electrode is provided and cyclohexanol is added to the electrolyte to prevent generation of foam on charge ; also, the electrolyte flows through the cell on charge and discharge. The cell may include a separator to form separate anolyte and catholyte compartments, the anolyte containing the polycation.