Influence of Some Metal Oxide Additives on the Performance of Porous Zinc Electrode

The effects of small additions of Bi₂O₃, SeO₂ and SnO₂ to the porous zinc electrode have been evaluated through cyclic voltametry, potentiodynamic polarization, A. C. impedance technique, solution analysis and porosity measurements. Though the additive Bi₂O₃ has the better ageing behaviour, it suffers from bulging and shape change - a serious setback for use in batteries and hence not recommended. 2% SeO₂, composition has better corrosion and ageing behaviour compared to SnO₂ additive. Bi₂O₃ and SeO₂ follow the same mechanism for the dissolution reaction, while SnO₂, with two additional peaks follows a different mechanism. A detailed analysis of the results obtained with the electrodes are presented in this paper to choose the better electrode additive for secondary alkaline batteries.