Lead-acid storage battery

How to make a lead-acid storage battery

Scientific name: Oxidation-reduction of lead as an electrochemical reaction

YouTube

Lead-acid storage battery

by Hegelrast

Electrochemical Reaction in Lead Acid Battery

by MyStuffofTech

Working Principle of Lead Acid Battery

by S Ghosh

How a lead-acid battery works

by engineerguy

4 Plate Crystal Lead Alum Hydrate Cell

by Energenx

How Lead Batteries are Made

by HowStuffWorks

Lead Plate and Alum Cell Demonstration

by OUbrads

Safety

Wear eye protection goggles. Gloves.

Always follow general safety recommendations. Please note that conducting chemistry experiments you must comply with the relevant legal procedures in your country.

Reaction formula

First charge

Pb + 2 H2O → PbO2 + 4H+ + 4e-

2 H+ + 2 e- → H2

resulting equation

Pb + 2 H2O → PbO2 + 2 H2

Discharge

PbO2 + 4 H+ + SO42- + 2e- → PbSO4 + 2 H2O /anode/

Pb + SO42- → PbSO4 + 2e- /cathode/

resulting equation

Pb + PbO2 + 2 H2SO4 → 2 PbSO4 + 2 H2O

Following charges

PbSO4 + 2 H2O → PbO2 + 4 H+ + SO42- + 2e- /anode/

PbSO4 + 2e- → Pb + SO42- /cathode/

resulting equation

2 PbSO4 + 2 H2O → Pb + PbO2 + 2 H2SO4

Reagents

  1. Lead

Step-by-step instruction

WARNING! This experiment is dangerous! You should NOT perform this at home. ONLY carry out this experiment, if you are a trained chemist, and you understand local safety and legal requirements, which are required to perform such experiments

  1. Take a sheet of lead. Attach it to the plastic mesh.
  2. Fold the plate so that it has three parallel layers (see. The first video).
  3. Put the system into a beaker. Fill the glass with sulfuric acid (3M) so that the upper layers of the plate edge slightly stands out.
  4. Connect the wires to the plate boundary layers using alligator clips.
  5. Connect the system to the power source. It takes a few hours to fully charge such a homemade battery. However, it will be usable after a few minutes for demonstration.
  6. Disconnect the system from the power supply and connect it to a lamp, a diode or a motor.
  7. Make sure that the battery is working.

Scientific background

The principle of operation of lead-acid batteries is based on the electrochemical reactions of lead and lead dioxide in an aqueous solution of sulfuric acid.

When the external power source is connected to the electrodes of the battery, the electrochemical reaction of lead oxide and sulfuric acid begins, metallic lead is oxidized to lead sulfate (the classic version battery). In fact, the electrochemical processes in the battery are more complicated.

During discharge the recovery of lead dioxide occurs on the anode, and the oxidation of lead on the cathode. Reversible reactions occur during charging. Electrolysis of water starts to overcharge the battery, lead sulfate after exhaustion, while oxygen is released at the anode (positive electrode) and hydrogen is released on the cathode (negative electrode).

As a result, the spent sulfuric acid from the electrolyte during discharge of the battery (when the density of the electrolyte decreases as the concentration of the acid solution is reduced during charging and, when the sulfuric acid is released in the reactions with the electrolyte solution of lead sulfate, the density of electrolyte increases). At the end of charging, when the amount of lead sulfate on the electrodes decreases below a certain critical value the process of water electrolysis begins to dominate. Hydrogen and oxygen are extracted from the electrolyte in the form of bubbles - the so-called "boiling" overcharge. This undesirable phenomenon should be possibly avoided while charging, as water is consumed and the concentration and density of the electrolyte increases. Loss of water by electrolysis fills the battery banks refilling of distilled water.

Danger:
Coolness:
Difficulty:

Published on 20 April 2015

  • Fire
  • Heating with fire
  • Explosion
  • Poisoned gas
  • Organic
  • Electricity
  • Solution
  • Oxidation reduction
  • Color change
  • Precipitate
  • Gassing
  • Catalyst