Anode: Lead (Pb)

Cathode: a grid of lead packed with lead oxide (PbO₂)

Electrolyte: 38% solution of sulphuric acid (H₂SO₄)

The cell reactions are as follows :

Pb (s) + SO₂^-4(aq) ⇒ PbSO₄(s) + 2e^- (anode)

PbO₂(s) + SO₂^-4(aq) + 4H⁺(aq) +2e^-⇒ PbSO₄(s) +2H₂O(l) (cathode)

Pb(s) + PbO₂(s) +2H₂SO₄(aq)⇒ 2PbSO₄(s) +2H₂O(l)

(overall cell reaction)

On charging, all these reactions will be reversed.