IDENTIFICATION OF ORGANIC CORROSION-INHIBITORS SUITABLE FOR USE IN RECHARGEABLE ALKALINE ZINC BATTERIES

Inhibition of the corrosion of zinc in aqueous alkali by various organic compounds has been tested. The rates of hydrogen evolution due to the metal corrosion in these inhibitor environments have been monitored at 25 degrees C for a number of days. Except for a few of the tested compounds, all inhibited zinc corrosion to varying degrees. Inhibitor performance under electrochemical conditions has been checked for selected compounds that showed appreciable corrosion inhibition in the previous test. Thus zinc polarization is followed with and without these inhibitor environments under potentiostatic conditions. Corrosion potential and current density have been observed to play vital roles in determining suitable performance of inhibitors under battery situations. Inhibitor environments where zinc has produced nearly the same corrosion current density as in the standard (corrosion current density without an inhibitor) have performed well in battery situations. In such cases improved single and accumulated cycle capacities have been recorded in battery situations.