Local structure transformation of nano-sized Al-doped LiMn 2O 4 sintered at different temperatures

Abstract

LiMn 2O 4 and LiAl 0.15Mn 1.85O 4 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 LiMn 2O 4 and LiAl 0.15Mn 1.85O 4 powders were probed by means of Mn K-edge X-ray absorption spectroscopy (XAS). Al-doping was found to promote the sintering of spinel LiMn 2O 4 so that the degree of structural disorder around Mn atoms in LiAl 0.15Mn 1.85O 4 becomes lower than that of LiMn 2O 4, leading to an excellent capacity retention of this cathode material for lithium battery in charge–discharge cycle.