The delayed action of magnesium anodes in primary batteries: Part II. Theoretical studies

A physical model for the field-induced breakdown of the passive film on magnesium anodes has been developed based on experimental data on the delayed action of magnesium anodes. The model essentially involves, successively, metal dissolution at the metal-film interface, film-dilatation, and film breakdown. A theoretical analysis of the model has been carried out to obtain an explicit expression for the time dependence of the electrode potential during the delayed action phenomenon. The delay-time curves obtained are compared with experimental data, especially with regard to the effects of film thickness, ageing of the anode in solution, current density, temperature, etc. Finally, possible means of reducing the delayed action of magnesium anodes are predicted from the ‘metal dissolution-film dilatation-film breakdown’ model.