The effects of sq. wave potential on the growth rate of the anodic films on Pb-7 Sb and Pb-5 Sb-0.2 As in 4.5 mol/dm3 H2SO4 at 30?were studied by a cathodic linear potential sweep method. By applying the sq. wave potential with period of 3600 s, the potentials of the lead alloys were cycled between that corresponding to the charged conditions of a Pb-acid battery (3 different charge potentials were studied: 1.4, 1.3 and 1.2 V vs. Hg/Hg2SO4, resp.) and that to the discharged condition (1.0 V). The anodic films contain grains with many voids among them as observed with SEM. The surface layer of the grain is PbO2, however, the major constituent of the grain is probably PbO.PbSO4. The relation between the quantity of electricity used to form PbO.PbSO4 and the no. of charges is linear for a certain no. of charge-discharge cycles. The conductance of the film is mainly due to the high conductivity of the PbO2 boundary layers of the grains, especially when the grains are in close contact with one another under pressure.

Key words: SULFURIC ACID, MEMBRANE ELECTRODES, DIFFUSION COEFFICIENTS, ELECTRIC POTENTIAL, ANTIMONY ALLOYS, POLARIZATION, LEAD ALLOYS, BATTERY CHARGING, ANODE EFFECT, LEAD OXIDE