Lead storage battery can be recharged by passing electric current of suitable patential in opposite direction in which lead is again deposited at anode and PbO2 is deposited at cathode. The density of electrolyle i.e., H2SO4 again increases. The following cell reaction takes place during charging:
At Anode: Pb(s) + SO4-2(aq) → PbSO4(s) + 2e–
At Cathode: PbO2(s) + SO-2(aq) + 4H+(aq) + 2e– → PbSO4(s) + 2H2O(l)
Overall reaction: Pb(s) + PbO2(s) + 2H2SO4(aq) → 2PbSO4(s) + 2H2O(l)
