Materials Used in Battery Chargers

Lead-acid batteries use lead dioxide as the active material on the positive plate and spongy pure lead as the active material on the negative plate. The electrolyte is a sulfuric acid solution of a certain concentration, and the electromotive force between the plates is approximately 2V.

Ni-Cd batteries use nickel oxide powder as the active material on the positive plate and cadmium oxide powder on the negative plate. The active materials are encased in perforated steel strips and then pressed to form the positive and negative plates. The electrolyte is usually a potassium hydroxide solution. The open-circuit voltage is 1.2V.

Ni-metal hydride batteries use nickel oxide powder as the positive plate and a hydrogen-absorbing alloy as the negative plate. The electrolyte is a potassium hydroxide solution. The open-circuit voltage is 1.2V. Lithium-ion batteries use a LiCoO2 composite metal oxide to form the anode on an aluminum plate and a lithium-carbon compound to form the cathode on a copper plate. A submicron-sized microporous polyolefin film separator separates the plates. The electrolyte is an organic solvent. The open-circuit voltage is 3.6V.

Lithium polymer batteries are an improved version of lithium-ion batteries. They do not use electrolyte but instead use polymer electrolytes, making them more stable than lithium-ion batteries. The open-circuit voltage is 3.6V.