The effect of additives on the corrosion resistance of Zn electrode in alkaline battery system

Zn electrodes are widely used as an anode material in alkaline battery systems in highly concentrated KOH electrolyte. However, it is well known that their life cycle is significantly shortened due to dendrite growth caused by high dissolution and rapid electrochemical reaction. In this study, additives such as Ca(OH)£σ, citrate, tartrate, and gluconate were added to 40% KOH electrolyte solution at 25 and 5 wt.% Pb3O4 was mixed with the Zn electrode. The effects of both Pb3O4 and the additives on the electrochemical behavior of the Zn electrode were investigated through corrosion potential measurements, potentiodynamic polarization curves, cyclic voltammetry, and SEM photographs. The addition of Pb3O4 had a considerable effect on decreasing the corrosion rate of the Zn electrode, and the corrosion potential of the Zn electrode with Pb3O4 addition shifted to a more positive potential than that of a pure Zn electrode. However, upon addition of other additives, the corrosion potential was slightly shifted to the negative direction again. The addition of 4 kinds of additives appeared to play an important role in improving the corrosion resistance. Moreover, among the four additives, tartrate displayed a relatively good effect in terms of increasing the corrosion resistance as well as improving the discharging characteristics among.