Explain primary and secondary storage batteries? How can lead storage batteries produceelectric current?

Primary and secondary storage batteries are two types of batteries that store electrical energy.

1. Primary Storage Batteries: These are non-rechargeable batteries that convert chemical energy into electrical energy. Once the chemical energy is completely converted into electrical energy, the battery is exhausted and cannot be recharged. The chemical reactions in these batteries are irreversible. Examples of primary batteries include alkaline batteries and zinc-carbon batteries.

2. Secondary Storage Batteries: These are rechargeable batteries that can convert electrical energy back into chemical energy. This means that once the battery is exhausted, it can be recharged and used again. The chemical reactions in these batteries are reversible. Examples of secondary batteries include lead-acid batteries and lithium-ion batteries.

Lead storage batteries, also known as lead-acid batteries, produce electric current through a chemical reaction between lead, lead dioxide, and sulfuric acid. Here's a step-by-step explanation:

1. The battery consists of two types of plates: one made of lead (Pb) and the other made of lead dioxide (PbO2). These plates are immersed in sulfuric acid (H2SO4), which acts as an electrolyte.

2. When the battery is in use (discharging), the lead plate (anode) reacts with the sulfuric acid to form lead sulfate (PbSO4) and hydrogen ions (H+). This reaction releases electrons, which flow through the external circuit and provide electric current.

3. Simultaneously, at the lead dioxide plate (cathode), the hydrogen ions (H+), electrons from the external circuit, and lead dioxide (PbO2) react with the sulfuric acid to form lead sulfate (PbSO4) and water (H2O).

4. When the battery is being charged, the reactions are reversed. The lead sulfate and water are converted back into lead, lead dioxide, and sulfuric acid, making the battery ready for another discharge cycle.

This process of discharging and recharging can be repeated many times, which is why lead-acid batteries are classified as secondary storage batteries.