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 PbSO 4 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 PbSO 4 can be used as active material of lead acid batteries. Here, we report the preparation of PbSO 4 by facile chemical precipitation of aqueous lead acetate with sodium sulfate and its utilization as the positive active material. The results show that the PbSO 4 alone is not good enough for the purpose, but its mixtures with Pb 3 O 4 are as excellent as the industrial leady oxide. For example, the mixtures containing 5, 10, 20, and 30 wt.% of Pb 3 O 4 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 % Pb 3 O 4 remains 93 % capacity in 150, 100 % DOD cycles.