While charging the lead storage battery, ………
PbSO4 on anode is reduced to Pb
PbSO4 on cathode is reduced to Pb
PbSO4 on cathode is oxidized to Pb
PbSO4 on anode is oxidized to PbO2
During charging lead storage battery.
At the anode: PbSO4+2e−→Pb+SO2−4