Rationalization of the low-potential reactivity of 3d-metal-based inorganic compounds toward Li

The unusual low-potential Li reactivity toward simple 3d-metal oxides can be accounted for by classical thermodynamic predictions and simple acido-basic considerations. The Smith's scale, defined in solids for acido-basic reactions involving O2- species exchange, is successfully used to check that, among the numerous simple oxides, the basic ones such as MnO, FeO, CoO, NiO, and CuO should reversibly react with lithium. Besides the basicity criteria, we stressed that the nanometric character of the reduced composite electrode (e.g., metallic nanoparticles immersed in a highly divided Li2O media) is a must to enable the reversible reactivity of metal oxides toward Li. Such a simple approach was finally implemented to other compounds (sulfides, nitrides, vanadates...) and the predictions confronted with experimental data. (C) 2002 The Electrochemical Society.