Lead Acid Battery: How Do They Work? Working Principle

 

Lead Acid Battery: How Do They Work?  Working Principle

Lead-acid battery working principle

let's have a discussion on working principle of lead-acid battery this is very commonly used as storage battery or secondary battery before going through the working principle we should know about materials used for lead-acid storage battery cells the main active materials required to construct a lead-acid battery are led peroxide sponge LED and dilute sulfuric acid the positive plate of lead-acid the battery is made of lead peroxide this is dark brown hard and brittle substance the negative plate of lead-acid battery is made of pure lead in a soft sponge condition dilute sulphuric acid used for lead-acid battery has a ratio of water is 2 acid equal to 3 is to 1 the lead-acid the 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 acid split into positive hydrogen ions and negative sulfate ions the hydrogen ions will reach lead peroxide plate they receive electrons from it and become hydrogen atom which again attacked lead peroxide and form lead oxide and water this led oxide reacts with sulfuric acid and forms lead sulfate and water negative sulfate ions are moving freely in the solution, so some of them will reach to the pure LED plate where they give their extra electrons and become radical sulfate as the radical sulfate cannot exist alone it will attack pure LED and will form lead sulfate as positive hydrogen ions take electrons from lead peroxide plate and negative sulfate ions give electrons to lead plate there would be an inequality of electrons between these two plates hence there would be a flow of current through the external load between these plates for balancing this inequality of electrons this process is called discharging of lead acid battery now we will disconnect the load and connect lead sulfate covered lead peroxide plate with the positive terminal of an external DC source and lead peroxide covered lead plate with the negative terminal of that DC source during discharging the density of sulfuric acid Falls but they're still sulfuric acid exists in the solution this sulfuric acid also remains as positive hydrogen ions and negative sulfate ions in the solution hydrogen ions being positively charged moved to the electrode connected with the the negative terminal of the DC source here each hydrogen ion takes one electron from that and becomes hydrogen atom these hydrogen atoms then attack lead sulfate and form lead and sulfuric acid negative sulfate ions move towards the the electrode connected with the positive the terminal of DC source where they will give up their extra electrons and become radical sulfate this radical sulfate reacts with lead sulfate of anode and forms lead peroxide and sulfuric acid hence by charging the lead acid storage battery cell becomes ready for discharging thank you