In a lead-acid battery the energy is stored in the form of

Lead-acid battery:

• Lead-acid batteries are rechargeable batteries with having small energy-to-volume ratio.
• Despite having a small energy-to-volume ratio and a very low energy-to-weight ratio, its ability to supply high surge contents reveals that the cells have a relatively large power-to-weight ratio.
• The energy in a lead acid battery is stored in the form of chemical energy.
• Lead-acid batteries can be classified as secondary batteries. The chemical reactions that occur in secondary cells are reversible.
• The reactants that generate an electric current in these batteries (via chemical reactions) can be regenerated by passing a current through the battery (recharging).

Additional InformationLead-acid battery: The battery uses spongy lead and lead peroxide for the conversion of chemical energy into electrical power, such type of battery is called a lead-acid battery. The lead-acid battery is most commonly used in power stations and substations because it has higher cell voltage and lower cost. It is a reversible battery.

The active elements of the lead-acid are

• Lead peroxide (PbO2): It forms the positive active material; The PbO2 is dark chocolate brown in color
• Spongy lead: It forms the negative active material; It is grey in color
• Dilute Sulfuric Acid (H2SO4) – It is used as an electrolyte; It contains 31% of sulfuric acid

Charging reaction:

PbO2 + H2SO4 + Pb → PbSO4 + 2H2O + PbSO4 + Electrical energy

Discharging reaction:

PbSO4 + 2H2O + PbSO4 + Electrical energy → PbO2 + H2SO4 + Pb