The lead–acid cell can be demonstrated using sheet lead plates for the two electrodes. However, such a construction produces only around one ampere for roughly postcard-sized plates, and for only a few minutes. Gaston Planté found a way to provide a much larger effective surface area. In Planté's design, the positive and negative plates were formed of two spirals o.
What is a lead acid battery?
A lead acid battery consists of a negative electrode made of spongy or porous lead. The lead is porous to facilitate the formation and dissolution of lead. The positive electrode consists of lead oxide. Both electrodes are immersed in a electrolytic solution of sulfuric acid and water.
Voltage of lead acid battery upon charging. The charging reaction converts the lead sulfate at the negative electrode to lead. At the positive terminal the reaction converts the lead to lead oxide. As a by-product of this reaction, hydrogen is evolved.
Terminals: Connect the battery to the external circuit. Figure 1: Lead Acid Battery. The battery cells in which the chemical action taking place is reversible are known as the lead acid battery cells. So it is possible to recharge a lead acid battery cell if it is in the discharged state.
To ensure optimum performance, regularly clean any lead oxide buildup on the terminals. The construction of lead acid batteries involves several key components. Each battery contains two lead plates, one made of lead dioxide and the other of sponge lead, submerged in sulfuric acid electrolyte.
The chemistry of lead-acid batteries involves oxidation and reduction reactions. During discharge, lead dioxide and sponge lead react with sulfuric acid to produce lead sulfate (PbSO4) and water. When recharged, the process is reversed, regenerating lead dioxide, sponge lead, and sulfuric acid.
What are the problems encountered in lead acid batteries?
Potential problems encountered in lead acid batteries include: Gassing: Evolution of hydrogen and oxygen gas. Gassing of the battery leads to safety problems and to water loss from the electrolyte. The water loss increases the maintenance requirements of the battery since the water must periodically be checked and replaced.