When Gaston Planté produced his first prototype in 1859, he had no idea of the different types of lead acid batteries that would follow. His was a simple affair: two lead sheets separated by a strip of cloth rolled into a spiral, and immersed in a sulfuric acid solution. However, it did keep train lights burning while in a station.
The Two Main Types of Lead Acid Batteries in Use Today
Lead acid batteries use lead dioxide for the positive electrode, and metallic lead for the negative. These two components are held in separate grids, while a sulfuric acid solution floods the container holding them.
The active materials in the electrodes react with the sulfuric acid electrolyte in flooded lead acid batteries. This reaction produces lead sulfate during discharge that almost completely reverses on discharge. The design requires replenishment of the water in the electrolyte via removable caps.
Vented lead acid batteries are an improvement over this design. They have openings that allow free passage of the byproducts of electrolysis and evaporation. They are also relatively cheap to produce, but need well-ventilated space.
Valve regulated batteries are the second of the basic types of lead acid batteries. In this instance, the electrolyte is in a mat, or it is a gel. Pressure relief valves substitute for the removable filler caps so the battery cannot leak.
Sealed, valve regulated batteries are increasingly popular. These replace the traditional ‘wet’ electrolyte with an immobilized one far less likely to leak, and an extended shelf life.
Why Are Lead Acid Batteries Still With Us Today
In theory they should not be, on account of their size and weight. However, they are cheaper and easier to make than lithium ion ones. Moreover, lead is in ample supply although most of it in any case comes from recycled batteries. Sometimes it is still true the old ways are better. Although a time must come when we will no longer need their faithful lead acid design.
Related
Gaston Planté’s Lead-Acid Cell Battery
How Auto Lead Acid Batteries Work
Preview Image: Recycling Molten Lead From Batteries