A lead-acid battery, a widely used type of rechargeable battery, consists of three main parts:
1. **Positive Plate**: This plate is made of lead dioxide (PbO₂). It is the positive electrode of the battery. When the battery discharges, the lead dioxide reacts with sulfuric acid to form lead sulfate (PbSO₄) and water. During charging, the lead sulfate is converted back into lead dioxide.
2. **Negative Plate**: The negative plate is made of spongy lead (Pb). It is the negative electrode of the battery. In the discharge process, the spongy lead reacts with sulfuric acid to form lead sulfate and water. During charging, the lead sulfate is converted back into spongy lead.
3. **Electrolyte**: The electrolyte is a sulfuric acid (H₂SO₄) solution. It is contained in the space between the positive and negative plates. The electrolyte facilitates the chemical reactions between the plates, allowing the battery to store and release electrical energy.
These three components work together to enable the lead-acid battery to store electrical energy chemically and convert it back to electrical energy as needed.