Lead sulfate used as the positive active material of lead acid batteries

Lead sulfate is produced when a lead acid battery discharges, and it is also known that big PbSO4 crystals are less active than the smaller ones because they dissolve slower, thus result in failure of the battery. However, little is known if chemically prepared PbSO4 can be used as active material of lead acid batteries. Here, we report the preparation of PbSO4 by facile chemical precipitation of aqueous lead acetate with sodium sulfate and its utilization as the positive active material. The results show that the PbSO4 alone is not good enough for the purpose, but its mixtures with Pb3O4 are as excellent as the industrial leady oxide. For example, the mixtures containing 5, 10, 20, and 30 wt.% of Pb3O4 discharge 78.2, 92.9, 88.0, and 91.5 mAh g−1 at a current density of 100 mA g−1, respectively. Also, the one with 10 % Pb3O4 remains 93 % capacity in 150, 100 % DOD cycles.