EFFECT OF SILICATE AND PHOSPHATE ADDITIVES ON THE KINETICS OF THE OXYGEN EVOLUTION REACTION IN VALVE-REGULATED LEAD ACID BATTERIES/

Effect of sodium silicate and phosphoric acid additives on the kinetic s of oxygen evolution on PbO2 electrodes in sulfuric acid has been stu died in gelled and flooded electrolytes with relevance to valve-regula ted lead/acid batteries. A comparison of the open-circuit potential ve rsus time transients, with and without these additives, indicates that the additives suppress self-discharge of the electrodes. Tafel polari zation studies also suggest that the addition of phosphoric acid atten uates the rate of oxygen evolution reaction. These findings have been supported with cyclic voltammetric data. (C) 1998 Elsevier Science S.A .