BEHAVIOR OF LEAD ELECTRODES IN SULFURIC ACID SOLUTIONS. II

Abstract : An attempt was made to clarify the question whether the variation in the length of the 'first discharge plateau' with change in H2SO4 concentration was caused by a change in the efficiency of PbO2 formation or by a variation in its discharge rate. The relationships between acid concentration, 'passivation time', amount of PbSO4 formed during passivation, and the quantity of PbO2 derived therefrom during charging were investigated. The amount of PbSO4 on the anode increased with a decrease in passivating acid concentration. More PbO2 was formed at lower charging acid concentrations. The higher the discharge acid concentration, the greater was its stabilizing effect on PbO2 discharge. The combination of two factors i.e. a decrease of the amount of PbO2 formed at higher acid concentrations together with an increase in the PbO2 stability, gave rise to the maximum 10.5 N H2SO4. (Author)