Mg2+ and Ti4+ Co–Doped Spinel LiMn2O4 as Lithium‐Ion Battery Cathode

Abstract Herein, Mg 2+ and Ti 4+ co‐doped spinel LiMn 2 O 4 lithium‐ion cathode material was prepared via a simple high‐temperature solid‐state route, presenting the high specific capacity, upgraded cyclability, and enhanced rate capability contemporaneously. The introduction of Mg 2+ reducing the relative content of Mn 3+ in the LiMn 2 O 4 material could not only well restrain the Jahn‐Teller effect due to the average‐valence increment of manganese, but also highly maintain the stability of cubic spinel structure upon cycling by virtue of stronger bond energy of Mg−O compared with Mn−O. What's more, Ti 4+ doping with a replacement of Mn 4+ increases the lattice parameter of LiMn 2 O 4 which could facilitate the insertion and deinsertion of Li + , and could also offer a positive effect to suppress the dissolution of manganese via changing the surface microstructure of material. Therefore, the co‐doped LiMn 2 O 4 electrode exhibits a high Li + storage capacity (124 mAh g −1 at 0.1 C), good capacity‐retention rate (97% after 100 cycles at 5 C), enhanced rate capability (85 mAh g −1 at 5 C) and improved cycling performance (80 mAh g −1 after 100 cycles at 5 C).