Alkaline-earth metal doping in spinel LiMn2O4 cathode materials for Li-ion batteries: Insights from first-principles calculations

Abstract

Spinel LiMn2O4 is regarded as a promising cathode material candidate due to its advantages of environmental friendliness and low cost. However, its development is hindered by unstable cyclic performance and limited energy density. Herein, alkaline-earth metal Mg doping in spinel LiMn2O4 cathode material was investigated based on first-principles calculations. The results show that the substitution of Mg2+ for Mn3+ is thermodynamically favorable. At the same time, adjacent Mn3+ is oxidized to Mn4+, which weakens the Jahn-Teller distortion of the LiMn2O4 cathode. The study also found that Mg and O have strong coupling near the Fermi level, which improves cycling stability. In addition, it is found that alkaline-earth metal doping is beneficial to the enhancement of intercalation potential. These findings will provide a theoretical reference for improving the performance of LiMn2O4 cathode material and promote the development of LiMn2O4 in power batteries.