The conventional strategy of overcharge protection for lithium ion batteries uses redox molecules having oxidation potential higher than the cathodic materials in the electrolyte. Here we propose a novel approach by using redox molecules having reduction potentials lower than the anodic materials. This new approach is successfully demonstrated in TiO2/LiCoO2 and TiO2/LiFePO4 cells by using benzophenone molecule. (C) 2007 Published by Elsevier B.V.