Lead acid cell; Principle of operation and components

🔋 Lead Acid Cell: Principle of Operation and Components

⚡ Introduction

The Lead Acid Cell is one of the oldest and most widely used types of rechargeable batteries. It is known for its reliability, ease of manufacture, and cost-effectiveness. 🚗🔋

🔍 Principle of Operation

The working principle of a Lead Acid Cell is based on the conversion of chemical energy into electrical energy and vice versa. 🔄⚡

When Discharging: The chemical reaction between lead dioxide (PbO₂) and sponge lead (Pb) in the presence of sulfuric acid (H₂SO₄) produces electrical energy. ⚡🔋

When Charging: An external electric current reverses the chemical reaction, restoring the original chemical composition of the electrodes. 🔄🔌

🛠️ Components of a Lead Acid Cell

1️⃣ Positive Plate (Anode) 🔴

• Made of lead dioxide (PbO₂).
• Has a dark brown color.
• Participates in the chemical reaction to release electrons. ⚡

2️⃣ Negative Plate (Cathode) 🔵

• Made of pure sponge lead (Pb).
• Has a gray color.
• Absorbs electrons during the chemical reaction. ⚡

3️⃣ Electrolyte 💧

• A dilute solution of sulfuric acid (H₂SO₄).
• Facilitates the movement of ions between plates.
• Concentration decreases as the battery discharges. 🧪

4️⃣ Separators 🧱

• Placed between positive and negative plates.
• Prevent direct contact and short-circuiting. 🚫⚡
• Made from materials like rubber, PVC, or glass fiber. 🛡️

5️⃣ Container 🏺

• Houses the plates, separators, and electrolyte.
• Made of hard rubber, plastic, or polypropylene.
• Strong, durable, and resistant to acid corrosion. 🛡️💪

6️⃣ Vent Caps 🛡️

• Allow gases to escape during charging. 💨
• Prevent spillage and contamination. 🧴

🎯 Chemical Reactions in Lead Acid Cell

➡️ During Discharge:

PbO₂ + Pb + 2H₂SO₄ → 2PbSO₄ + 2H₂O

The plates become coated with lead sulfate (PbSO₄) and water is formed, diluting the electrolyte. 🔋➡️⚡

⬅️ During Charging:

2PbSO₄ + 2H₂O → PbO₂ + Pb + 2H₂SO₄

The original materials are regenerated, and the battery gets ready to supply power again! 🔋🔄⚡

🏆 Advantages of Lead Acid Batteries

• Low cost. 💰
• High reliability. ✅
• Good performance under heavy load. 🔥
• Simple charging methods. 🔌

⚠️ Disadvantages

• Heavy weight. ⚖️
• Limited cycle life compared to modern batteries. 🔄
• Maintenance required (checking electrolyte levels). 🛠️
• Risk of acid spillage. 🧪⚠️

🛠️ Applications of Lead Acid Cells

• Automobiles (Car batteries). 🚗
• Inverters and UPS systems. 🔋🏠
• Electric wheelchairs and scooters. 🛴♿
• Emergency lighting systems. 💡

📚 Conclusion

The Lead Acid Cell remains an important technology even today because of its cost-effectiveness and high surge capabilities. Despite newer battery technologies, lead-acid batteries continue to power vehicles, backup systems, and heavy-duty applications worldwide! 🌍🔋🚗