Local structure transformation of nano-sized Al-doped LiMn2O4 sintered at different temperatures

LiMn2O4 and LiAl0.15Mn1.85O4 were synthesized via the sol-gel process using citric acid as the chelating agent, followed by sintering at various temperatures. The electronic and atomic structures of LiMn2O4 and LiAl0.15Mn1.85O4 powders were probed by means of Mn K-edge X-ray absorption spectroscopy (XAS). Al-doping was found to promote the sintering of spinel LiMn2O4 so that the degree of structural disorder around Mn atoms in LiAl0.15Mn1.85O4 becomes lower than that of LiMn2O4, leading to an excellent capacity retention of this cathode material for lithium battery in charge-discharge cycle. (C) 2003 Published by Elsevier Science B.V.