First-principles studies of cation-doped spinel LiMn2O4 for lithium ion batteries -: art. no. 115130

The electronic structure of Cr-doped LiMn2O4 spinels was investigated from first principles. It was found that the structure of material is more favorable in total energy when the doping chromium atoms are dispersed in LiMn2O4. With increasing Cr dopant, more electrons are transferred to the oxygen while the positive valence states of Mn atoms are less affected. Consequently, the doping Cr ions possess a higher valence than Mn in LiMn2O4, agreeing qualitatively with previous experimental results. By combining first-principles methods with basic thermodynamics, average intercalation voltages of this doped system have been calculated. It was found that both the value of the calculated intercalation voltages and their varying trend with increasing Cr dopant are consistent with the experimental facts.