Electrochemical Performance of Iron‐doped Li1.2Mn0.6Ni0.2O2 Cathode Materials Prepared by Combustion Synthesis

Abstract Li‐rich manganese cathode materials have increasingly attracted much attention because of their high specific capacities applied in Li‐ion batteries. However, they have suffered from low coulombic efficiency and poor rate capability. In this study, we utilize Fe ion doping and control grain morphology to improve the electrochemical performance of Li 1.2 Mn 0.6 Ni 0.2 O 2 . Fe‐doped Li 1.2 Mn 0.6 Ni 0.2 O 2 powders were successfully prepared via combustion synthesis, with equiaxed appearance and submicron size. The electrochemical measurement demonstrated that through Fe doping, a high discharging capacity of 192.0 mAh⋅g −1 was achieved for the sample at the rate of 1 C, and the cyclic stability and rate capacity were significantly enhanced compared. Further investigations illustrated that Fe ions manifested electrochemical activity during lithiation and delithiation, and enabled to stabilize hexagonal structure of the sample and enlarge the crystal interlayer spacing. It is the synergistic effect that endows the doped sample more specific capacity and high cyclic and rate performance.