New types of polymer lithium ion batteries, formed by combining a Li4Ti5O12 anode with a LiMn2O4 and a LiNi0.5Mn1.5O4 cathode, respectively, in a poly(vinylidene fluoride) PVdF-based gel electrolyte cell, are presented and discussed. The operating voltage is around 2.5 V for the battery based on LiMn2O4 and around 3.0 V for that based on LiNi0.5Mn1.5O4. The electrochemical characterization demonstrates that these high- voltage batteries are capable of delivering appreciable capacity values at various rates, this being accompanied by a remarkable cycle life. In addition, since the two electrodes are based on common and not toxic materials and operate within the stability window of the electrolyte, the batteries are expected to be safe, inexpensive, and compatible with the environment. All these properties make the batteries of interest for application in the hybrid and electric vehicle field. (c) 2005 The Electrochemical Society.