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

Electrical4U

9 May 201304:00

Summary

TLDRThe 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.

Outlines

00:00

🔋 Working Principle of Lead Acid Battery

The paragraph discusses the working principle of a lead acid battery, a commonly used storage or secondary battery. The battery is constructed with lead peroxide for the positive plate, sponge lead for the negative plate, and dilute sulfuric acid as the electrolyte. During discharge, sulfuric acid molecules split into hydrogen ions and sulfate ions. Hydrogen ions react with the lead peroxide plate to form lead oxide and water, while sulfate ions react with the sponge lead plate to form lead sulfate. This creates an electron imbalance, leading to current flow through an external load. Charging the battery involves reversing the process using an external DC source, which converts lead sulfate back into lead peroxide and sponge lead, and replenishes the sulfuric acid.

Mindmap

Keywords

💡Lead Acid Battery

A lead acid battery is a type of rechargeable battery that is widely used for its reliability and low cost. It consists of lead dioxide for the positive electrode, sponge lead for the negative electrode, and dilute sulfuric acid as the electrolyte. The script discusses the working principle of this battery, highlighting its use as a storage battery or secondary battery, which is crucial for understanding the video's theme of energy storage and conversion.

💡Lead Peroxide

Lead peroxide is a dark brown, hard, and brittle substance used in the construction of the positive plate of a lead acid battery. It plays a vital role in the discharge process where it reacts with hydrogen ions to form lead sulfate and water. This chemical transformation is central to the battery's ability to store and release electrical energy, as explained in the script.

💡Sponge Lead

Sponge lead refers to pure lead in a soft, porous form used for the negative plate of a lead acid battery. During the discharge process, it reacts with sulfate ions to form lead sulfate. The term 'sponge' is used to describe the material's ability to absorb and release ions, which is essential for the battery's function, as depicted in the script.

💡Dilute Sulfuric Acid

Dilute sulfuric acid is the electrolyte in a lead acid battery, with a water-to-acid ratio of 3:1. It facilitates the flow of ions between the positive and negative plates, enabling the battery to conduct electricity. The script emphasizes the importance of this electrolyte in the operation of the battery, as it is the medium through which the chemical reactions that generate electricity occur.

💡Discharging

Discharging refers to the process where a battery converts stored chemical energy into electrical energy. In the context of the script, discharging occurs when the lead peroxide plate loses electrons to hydrogen ions, and the sponge lead plate gains electrons from sulfate ions, resulting in the formation of lead sulfate at both electrodes and the flow of current.

💡Lead Sulfate

Lead sulfate is a compound formed during the discharge of a lead acid battery when lead peroxide and sponge lead react with sulfuric acid. It is a key intermediate product in the battery's chemical reactions, as highlighted in the script. The formation of lead sulfate at both electrodes during discharge is indicative of the battery's state of charge.

💡External Load

An external load refers to any device or system that draws electrical power from the battery. In the script, connecting an external load between the positive and negative plates of the battery initiates the discharge process, causing a flow of electrons that can be used to power devices. The load is a critical component in the practical application of the battery's stored energy.

💡DC Source

A DC source, or direct current source, is a device that provides a constant flow of electric charge in one direction, which is necessary for charging a lead acid battery. The script describes how, during charging, the lead sulfate-covered plates are connected to the positive and negative terminals of an external DC source to reverse the discharge process and restore the battery's active materials to their original state.

💡Charging

Charging is the process of converting electrical energy back into chemical energy by supplying power to a battery. The script explains that after a battery has been discharged, it can be recharged by connecting it to a DC source, which causes the lead sulfate at the electrodes to revert back to lead peroxide and sponge lead, readying the battery for another discharge cycle.

💡Electrode

Electrodes are the conductive terminals through which current enters or leaves a battery. The script mentions the positive and negative electrodes, which are made of lead peroxide and sponge lead, respectively. These electrodes are crucial for the battery's operation as they are the sites of the chemical reactions that enable energy storage and release.

💡Ions

Ions are atoms or molecules that have gained or lost electrons, resulting in a net electrical charge. The script describes how hydrogen ions (protons) and sulfate ions are involved in the chemical reactions at the electrodes during both discharging and charging. The movement of these ions through the electrolyte is fundamental to the battery's ability to generate and store electricity.

Highlights

Lead acid batteries are commonly used as storage or secondary batteries.

The main materials for lead acid batteries include lead peroxide, sponge lead, and dilute sulfuric acid.

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

The negative plate consists of pure lead in a soft, sponge-like condition.

Dilute sulfuric acid for lead acid batteries has a water to acid ratio of 3:1.

Lead acid storage batteries are formed by immersing lead peroxide and sponge lead plates in dilute sulfuric acid.

During discharge, hydrogen ions receive electrons from the lead peroxide plate to form hydrogen atoms.

Lead oxide reacts with sulfuric acid to form lead sulfate and water.

Negative sulfate ions give electrons to the pure lead plate, forming lead sulfate.

An electron imbalance between plates during discharge creates a current flow through the external load.

The process of balancing electron inequality is called discharging of the lead acid battery.

During charging, the density of sulfuric acid decreases, but it still exists in the solution.

Hydrogen ions move to the electrode connected with the negative terminal of the DC source during charging.

Hydrogen atoms attack lead sulfate to form lead and sulfuric acid during the charging process.

Negative sulfate ions move towards the positive terminal of the DC source and form radical sulfate.

Radical sulfate reacts with lead sulfate of the anode to form lead peroxide and sulfuric acid during charging.

Charging prepares the lead acid storage battery cell for discharging.