Synthesis and electrochemical characterization of Li1.05RExCryMn2-x-yO4 spinel as cathode material for rechargeable Li-battery

The spinel phases of Li1.05RExCryMn2-x-yO4 (RE= Sc, Ce, Pr, Tb; 0 <= x <= 0.05; 0 <= y <= 0.1) were prepared by a soft chemical method. The structural and electrochemical properties of Li1.05RExCryMn2-x-yO4 were investigated by X-ray diffraction (XRD), Transmission electron microscopy (TEM) and charge-discharge experiments. Rare earth element-Sc and transition metal-Cr as co-substituents stabilize the spinel framework and improve charge-discharge performance. For Li1.05Sc0.01Cr0.03Mn1.96O4, the capacity of the cell maintained 95% of the initial capacity at the 80th cycle. The rare earth elements of the variable valent metals such as Ce3+/4+, Pr3+/4+, Tb3+/4+ with transition metal Cr3+ as co-substituent do not stable framework of spinel or improve the cycling performance. Cyclic voltammetry CV) were measured to provide clues for the improved cycling performance of cathode electrodes. (C) 2007 Published by Elsevier B.V.