Lead Storage Battery

Materials: ★★☆ Available in most school laboratories or specialist stores
Difficulty: ★☆☆ Can be easily done by most teenagers
Safety: ★★☆ Some safety precautions required to perform safely

Categories: Electrochemistry, Energy

Alternative titles: Rechargeable Lead-Acid Cell

Summary

This experiment demonstrates how a lead storage battery works by constructing a simple lead-acid cell, charging it with a direct-current power supply, and then discharging it. It illustrates the reversible redox reactions that make rechargeable batteries possible.

Procedure

Prepare two lead electrodes: one made of lead metal and the other coated with lead dioxide (or simulate this with treated lead strips).
Place both electrodes into a beaker containing sulfuric acid solution (approximately 1–2 M).
Connect the electrodes to a DC power supply and charge the cell until a measurable voltage is observed.
Disconnect the power supply and attach a voltage probe across the electrodes to measure the stored potential.
Connect the charged cell to a meter or low-power device to demonstrate energy discharge.

Links

Lead Acid Batteries: How They Work - Electromagnetic Videos:

📄 Lead Storage Batteries - Vernier: https://www.vernier.com/experiment/cwv-29_lead-storage-batteries/?srsltid=AfmBOorM5GXUxVms_ucMcorRemM81SNcQNucOK7ZSj-4e3EEmkurTu_j

Variations

Connect multiple lead-acid cells in series to increase the output voltage.
Use different concentrations of sulfuric acid to test effects on performance.

Safety Precautions

Wear safety goggles, gloves, and a lab coat when handling sulfuric acid.
Handle lead electrodes with care—lead is toxic and should not be touched with bare hands.
Dispose of sulfuric acid and lead waste properly as hazardous materials.
Avoid short-circuiting the electrodes, as this may cause overheating.
Ensure good ventilation during the experiment, as small amounts of hydrogen gas may be produced.

Questions to Consider

What reactions occur at the lead and lead dioxide electrodes during discharge? (Pb → PbSO₄ + 2e⁻ at the anode; PbO₂ + 4H⁺ + SO₄²⁻ + 2e⁻ → PbSO₄ + 2H₂O at the cathode.)
How does charging reverse the discharge reaction? (The applied current drives the reverse redox reactions, regenerating Pb and PbO₂ from PbSO₄.)
Why is sulfuric acid essential for the operation of the battery? (It supplies sulfate ions for the redox reactions and maintains ionic conductivity.)
Why are lead-acid batteries still used today despite being heavy and containing toxic materials? (They are inexpensive, reliable, and capable of delivering high surge currents, such as in car engines.)