Al-M (M = Cr, Fe, Mn, Ni) thin-film negative electrode materials

Comprehensive investigations of thin-film Al-M (M = Cr, Fe, Mn, Ni) negative electrode material libraries were performed using combinatorial and high-throughput techniques. Mossbauer effect spectroscopy and X-ray diffraction were used to characterize library structure. The electrochemical performance of over 200 compositions of AlxM1-x (0.75 < x < 1) was determined at both room and elevated temperature. All AlxM1-x alloys are completely inactive above 15 atom % M. Thermodynamic calculations based on the macroscopic atom model of de Boer et al. predict compositions with at least 33-65 atom % M to be inactive. A phenomenological model to describe the observed capacity as a function of transition metal content and cycling temperature is presented. (c) 2006 The Electrochemical Society.