Lead Acid Battery: How Do They Work? | Working Animation | Electrical4U

Summary

The video script discusses the working principle of lead-acid batteries, commonly used as storage or secondary batteries. It details the materials involved, including lead peroxide, sponge lead, and dilute sulfuric acid. During discharge, lead peroxide and lead react with sulfuric acid to form lead sulfate and water, generating a flow of electrons through an external load. Recharging involves using an external DC source to revert lead sulfate back to lead peroxide and sponge lead, replenishing the battery for further use.

Takeaways

• 🔋 The lead acid battery is a common type of storage or secondary battery.
• 🏭 The main materials used in lead acid batteries are lead peroxide, sponge lead, and dilute sulfuric acid.
• 📍 The positive plate is made of lead peroxide, which is a dark brown, hard, and brittle substance.
• 🔩 The negative plate is composed of pure lead in a soft, sponge-like condition.
• 💧 Dilute sulfuric acid for the battery has a water to acid ratio of 3:1.
• ⚡ When a load is connected, the battery discharges by creating an electron imbalance between the plates.
• 🔁 During discharge, hydrogen ions take electrons from the lead peroxide plate, forming lead oxide and water, while sulfate ions give electrons to the sponge lead plate, forming lead sulfate.
• 🔄 The flow of current through the external load during discharge is due to the electron imbalance between the plates.
• 🔌 To recharge, the lead sulfate-covered plates are connected to an external DC source, with the lead peroxide plate connected to the positive terminal and the sponge lead plate to the negative.
• 🔄 During charging, hydrogen ions at the negative terminal take electrons to form hydrogen atoms, which react with lead sulfate to produce lead and sulfuric acid, while sulfate ions at the positive terminal give up electrons to form lead peroxide and sulfuric acid, readying the battery for discharge.

Q & A

What is a lead acid battery commonly used for?

A lead acid battery is commonly used as a storage battery or secondary battery.

What are the main active materials required to construct a lead acid battery?

The main active materials required are lead peroxide, sponge lead, and dilute sulfuric acid.

What is the composition of the positive plate in a lead acid battery?

The positive plate of a lead acid battery is made of lead peroxide, which is a dark brown, hard, and brittle substance.

What is the composition of the negative plate in a lead acid battery?

The negative plate of a lead acid battery is made of pure lead in a soft, sponge-like condition.

What is the ratio of water to acid in dilute sulfuric acid used for lead acid batteries?

The ratio of water to acid in dilute sulfuric acid used for lead acid batteries is 3:1.

How is a lead acid storage battery formed?

A lead acid storage battery is formed by dipping lead peroxide plates and sponge lead plates in dilute sulfuric acid.

What happens when a load is connected externally between the plates in diluted sulfuric acid?

When a load is connected, hydrogen ions reach the lead peroxide plate, receive electrons, and become hydrogen atoms. These atoms then form lead oxide and water, which react with sulfuric acid to form lead sulfate and water.

How does the flow of current occur during the discharging of a lead acid battery?

The flow of current occurs due to the inequality of electrons between the two plates, as hydrogen ions take electrons from the lead peroxide plate and sulfate ions give electrons to the lead plate.

What happens when the lead acid battery is disconnected from the load and connected to an external DC source?

During charging, hydrogen ions move to the electrode connected with the negative terminal of the DC source, take electrons, and form hydrogen atoms. These atoms then react with lead sulfate to form lead and sulfuric acid. Sulfate ions move to the positive electrode, give up electrons, and react with lead sulfate to form lead peroxide and sulfuric acid.

Why does the density of sulfuric acid fall during discharging?

The density of sulfuric acid falls during discharging because sulfuric acid is consumed in the reactions that form lead sulfate at both the positive and negative plates.

What is the purpose of charging a lead acid storage battery?

The purpose of charging a lead acid storage battery is to convert the lead sulfate back into lead peroxide and pure lead, making the battery ready for discharging again.