Possible future developments of lithium rechargeable batteries are discussed. Lithium ion liquid electrolyte batteries are now well established, with energy densities of up to around 150Whkg−1. There are prospects of increases in the energy density to perhaps 200–250Whkg−1 by using new cathode materials (lithium nickel cobalt oxide) and light weight construction. High power cells make it possible for these batteries to find new uses, e.g. in military applications. Some new materials could reduce the cost, which might make lithium rechargeable batteries economic for electric vehicles.