🔋 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! 🌍🔋🚗