Characteristics of a mercury substituent inhibitor in alkaline manganese dioxide/zinc batteries

Abstract

Manganese dioxide/zinc batteries are the most widely used portable electrochemical power source. Such cells cause serious environmental pollution due to the fact that mercury is used as an anode additive for inhibiting zinc corrosion and extending shelf life [1, 2]. The disposal of large quantity of used cells inevitably results in mercury pollution. So far there have been two approaches to achieving inhibition of zinc corrosion under the mercury-free condition [3±7]. One is to alter the properties of the zinc by alloying it with other elements, the other is to modify the property of the electrolyte by introducing additives. Research has been carried out in our laboratory where approximately one hundred kinds of additive have been tried, some of which are e€ective in inhibiting zinc corrosion in alkaline solutions [8, 9]. But since few have proved successful as complete substitutes for mercury, emphasis has been placed on the search for a composite addition agent. We have now found a nonpoisonous composite inhibitor (designated as HSJ) that has proved suitable as a substitute for mercury. The composite inhibitor is a mixture of a polyoxyethylene ether and a quarternary ammonium salt. The characteristics of HSJ as a substitute for mercury in alkaline manganese cells are described in this paper.