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.
The lead acid storage battery is formed by dipping lead peroxide plate and sponge lead plate in dilute sulfuric acid. A load is connected externally between these plates. In diluted sulfuric acid the molecules of the acid split into positive hydrogen ions (H +) and negative sulfate ions (SO 4 − −).
If we break the name Lead Acid battery we will get Lead, Acid, and Battery. Lead is a chemical element (symbol is Pb and the atomic number is 82). It is a soft and malleable element. We know what Acid is; it can donate a proton or accept an electron pair when it is reacting.
The construction of a lead acid battery cell is as shown in Fig. 1. It consists of the following parts : Anode or positive terminal (or plate). Cathode or negative terminal (or plate). Electrolyte. Separators. Anode or positive terminal (or plate): The positive plates are also called as anode. The material used for it is lead peroxide (PbO 2).
The lead acid battery is most commonly used in the power stations and substations because it has higher cell voltage and lower cost. The various parts of the lead acid battery are shown below. The container and the plates are the main part of the lead acid battery.