Common lead acid batteries in cars and trucks work by developing and storing electric potential between sets of positive and negative electrode plates. The electrodes are commonly made of Lead (Pb) and Lead Dioxide (PbO2) mesh and paste, separated by a non-conductive porous material to stop them touching and short circuiting. The battery cells are submerged in approximately 35% Sulphuric Acid (H2SO4(aq)) which acts as an electrolyte and allows electrons to flow between the plates and to deliver current when the battery terminals are connected to a circuit.
The basic energy storage and delivery concept of lead acid batteries was invented over a century and a half ago by French physicist Gaston Planté. Since that time, this kind of battery chemistry has been developed to become a standard and efficient workhorse in everyday life for us all.