The kinetic mechanism of the PbO2 discharge of the lead/acid positive plates

A kinetic mechanism is proposed for the discharge reaction of positive plates of lead/acid batteries. It includes several steps occurring at different times in each part of the electrode surface. The mechanism takes into account solid-state reactions at the beginning followed by a dissolution/precipitation mechanism. On this basis, experimental data are presented to show that the mechanism implies an intermediate stage in which the product behaves as a continuous film. Finally, data are presented showing that, up to this intermediate stage, the reaction product is a form of PbO that will react later with H2SO4 to give PbSO4.