The effect of orthophosphoric acid on lead dioxide electrodes

This thesis describes the effects of phosphoric acid on the positive lead dioxide electrode of a lead-acid cell. The aim of this research was to evolve a mechanism for the action of phosphoric acid on the charge (PbSO4→PbO2) and discharge (PbO2→PbSO4) processes. Industrially, phosphoric acid is added to the battery electrolyte because it has certain beneficial effects of preventing formation of 'hard' sulphate and reduction in shedding of active material resulting in improved cycle life. The main disadvantage of phosphoric acid-containing electrolyte is a reduction in capacity of the cell. [Continues.]