Lead-acid batteries are reliable alternatives to lithium-ion batteries and are used, for example, as a starter battery in vehicles. They have a lower energy density and durability than lithium-ion batteries, but are cheaper to purchase.
Lead-acid batteries also follow the principle of the galvanic cell.
Lead-acid batteries consist of two lead plates, serving as anode and cathode, in a housing filled with sulfuric acid (H2SO4). During discharge, the lead reacts with the acid, lead sulphate (PbSO4) is formed both at the anode and at the cathode. The chemical reaction releases electrons at the negative pole and electrons at the positive pole. During charging, lead dioxide (PbO2) is formed on the positive electrode and spongy lead on the negative electrode.