PURPOSE:To accelerate decomposition reaction in quick charge or in charge at low temperature to improve battery performance by specifying the contents of thallium or thallium compound and calcium hydroxide in a mixture. CONSTITUTION:The contents of thallium or thalium compound and calcium hydroxide are specified to 0.5-5wt.% and 5-20wt.% based on a mixture respectively. A dissolved species of thallium or thallium compound in alkaline electrolyte is Tl<+> ion. When calcium zincate is formed by the reaction of calcium hydroxide with zincate ion in discharge, thallium zincate is also formed by the existence of Tl<+> ion. In charge reaction, calcium hydroxide and zinc-thallium alloy is produced from the discharge products. By containing calcium hydroxide in the zinc electrode, the cycle life of the battery is increased and quick charge in a wide temperature range is made possible.