ABSTRACT
Batteries convert chemical energy directly into electrical energy. The energy reactions at the negative (anode) and positive (cathode) poles generate a voltage and occur only on demand when the external device is connected and the circuit is closed. The design of the battery separates the reactants to prevent the reactions from proceeding until the external circuit is closed. The ability to deliver energy and power is dependent on the quality and characteristics of the materials used to construct the battery/cell. There are two general classes of batteries, primary (single use and discard) and secondary or rechargeable (capable of being electrically restored to its original state for reuse). Within each of these general classes are many different systems distinguished by the chemistry that produces the conversion of chemical energy into electrical energy. Although many electrochemical systems can store chemical energy, only a few reactions meet the criteria for use in commercial systems for cost and storage as well as effi cient conversion of chemical energy into electrical energy.
