Cathodic processes on zinc in alkaline zincate solutions

The charging process of alkaline zinc secondary batteries is accompanied by the formation of hydrogen. Both the current and the coulombic efficiency, and in part the energy efficiency, are dictated by the production of hydrogen. Gasometric methods are used to determine the rates of hydrogen evolution and a potentiodynamic polarization method is employed to study the behaviour of zinc in alkaline solutions. It is found that an increase in ZnO concentration and a decrease in KOH concentration lower the rate of hydrogen evolution.