Investigations into the high pressure oxygen zinc-oxygen electrochemical couple

The zinc-oxygen battery couple costs per K.W. per annum fall just outside the cost target of f22/KW.p.a. (1974 prices) and the effect of increasing the oxygen pressure was investigated with the aim of increasing the mass transport of oxygen to the reaction zone and improving the efficiency of the couple to bring it within the desired cost target.The electrochemical activity of graphite, gold, silver and platinum electrodes for oxygen reduction in alkaline potassium hydroxide was investigated using the techniques of cyclic voltammetry, chronopotentiometry, differential chronopotentiometry and rotating disc electrode methods.It was found that the dissolved oxygen content within the electrolyte with increasing applied oxygen pressure followed a Henry law relationship and that this dissolved oxygen content was insufficient for a battery system. The mass transport of oxygen, however, was enhanced and improved the current density. Dendritic zinc electrodes were found to be less susceptible to dendritic short circuiting than pressed zinc powder and reduced zinc oxide electrodes. Zinc-oxygen battery couples were fabricated and tested under atmospheric and applied oxygen pressure and their discharge profiles investigated.