Flat polymer electrolytes promise thin-film power

An emerging solid-state battery that could be fabricated much thinner than 100 mu m and that uses a solid polymer electrolyte as the ionically conducting medium instead of a liquid electrolyte is described. Such batteries combine high energy density with mechanical ruggedness for applications ranging from smart cards to space. The major problem in developing using solid-state batteries has been identifying solid materials with sufficient ionic conductivity to serve as the electrolyte: the use of polymers to meet the requirement is discussed. The development of batteries that can withstand the elevated temperatures that are necessary to obtain adequate ionic mobility within the electrolyte component of the cell or are posed by application to electric-vehicle propulsion is considered. Application to smart credit cards is examined in some detail.<<ETX>>