The Effect of Phosphoric Acid on the Positive Electrode in the Lead‐Acid Battery: III . Mechanism

Abstract

Phosphoric acid added to battery electrolyte modifies the morphology of corrosion films by reacting to produce as an intermediate in the oxidation of Pb to . Because these modified films resist reduction to , battery failure from formation of a resistive film at the positive grid/active material interface is forestalled. Three new findings support this mechanism: (i) the identification of in lead corrosion films, (ii) the predictions of a thermodynamic model of the system, and (iii) the measurement of sulfation rates of films formed from and .