A lead storage battery consists of anode lead, cathode of a grid of lead packed with lead dioxide (PbO2)
and 38%
solution of sulphuric acid as electrolyte. When the battery is in use, the following reactions take place :
Anode:Pb(s)+SO
2-
4
(aq)→PbSO4(s)+2e-
Cathode :PbO2(s)+SO
2-
4
(aq)+4H⊕(aq)+2e-→PbSO4(s)+2H2O(l)
¯
Overall reaction:Pb(s)+PbO2(s)+2H2SO(aq)→2PbSO4(s)+2H2O(l)
̲
On CHMarging the battery, the reverse reaction take place, i.e., PbSO4
deposited on the electrodes is converted back into Pb
and PbO2
and H2SO4
is regenerated.
