Enhanced Electrochemical Performance of Li-rich Cathode Materials by Al Doping

Li-rich oxides are the most promising of the high-voltage cathode materials with their high specific capacity. However, Li-rich cathode materials suffer from structural instability, voltage degradation, and capacity fading upon cycling. Al-doping can improve electrochemical performance by stabilizing the structure and suppressing the phase transitions for Li-rich cathodes. In this paper, we investigate the effect of different amounts of Al with the general formula Li_1.2Mn_0.54-xNi_0.13Co_0.13Al_xO₂ and Li_1.2-xMn_0.54Ni_0.13Co_0.13Al_xO₂ (x=0.02, 0.05, 0.1) cathode materials. The Li and Mn elements were replaced by Al, and the electrochemical performance was compared to pristine Li_1.2Mn_0.54Ni_0.13Co_0.13O₂. The Li and Mn elements were replaced by Al, and the electrochemical performance was compared. The impact of substitution of Mn and Li by Al on the structural and morphological properties has been investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The charge and discharge tests show that doping with Al substitution leads to improved electrochemical performance, enhancing both the cycling stability and rate capability of the Li-rich cathode materials. Along with the improved specific capacities, these materials demonstrate superior rate performance, particularly for the composition with the lowest Al content.