Comparative study of Co, Cr and Al-doped LiMnO2 prepared by ion exchange

The Co, Cr and Al-doped LiMnO2 powders were prepared by ion exchange. Phase identification, surface morphology and electrochemical properties were studied by X-ray diffraction, scanning electron microscopy and galvanostatic charge-discharge experiments. The results show that the doped LiMnO2 keeps the structure of LiMnO2. As compared to LiMnO2, Co, Cr and Al-doped LiMnO2 offers higher discharge capacity and better cycling performance. The discharge capacities of Co, Cr and Al-doped LiMnO2 decreases yet the cycling performance improves with the increase of doping concentration. For these doped LiMnO2 at the same doping concentration, Cr-doping shows the highest discharge capacity and best cycling performance, Al-doping offers the lowest discharge capacity and Co-doping shows the worst cycling performance.