EFFECTS OF COBALT IN LEAD ACID BATTERIES

The effects of cobalt additions (0.1-1 g/l) to the electrolyte have be en studied by anodic corrosion tests on sheets of various alloys, and by continuous charge, cycling and charge retention tests on thick plat e automotive-type of batteries. Positive grid corrosion decreases with increase in cobalt concentration but the effect is less marked for al loys with high intrinsic corrosion resistance. Cobalt oxidizes some ty pes of separator even at a relatively low concentration. the top-of-ch arge voltage is reduced by the presence of cobalt, the effect occurrin g mainly at the positive plate. Cobalt causes increased open-circuit l osses but the effect is fairly small at low concentrations (0.1-0.15 g /l).