Write the chemistry of recharging the lead storage battery, highlighting all the materials that are involved during recharging.
A secondary cell after use can be recharged by passing current through it in the opposite direction so that it can be used again.
Recharging: During charging process, hydrogen ions moves to cathode and sulphate ions to anode and the following reactions take place
PbSO4 + H2 → Pb + H2SO4
PbSO4 + SO4 + 2H2O → PbO2 + 2H2SO4
Thus, during charging active materials namely Pb cut the cathode and PbO2 at the anode are formed. Sulphuric acid is formed and water is iconsumed. Due to this, the specific gravity of sulphuric acid increases and emf of the cell goes up to 2.2 volt.
= 1.05 V – 0.0295 x log 80
= 1.05 V – 0.0295 x 1.9031
= 1.05 V – 0.056 = 0.99 V.