Effects of Al doping on the electrochemical performances of LiNi0.83Co0.12Mn0.05O2 prepared by coprecipitation

Abstract The Ni-rich LiNi0.83Co0.12Mn0.05O2 (NCM83) cathode materials have drawn intensive attention due to the high energy density and low cost. However, Ni-rich LiNi1-x-yCoxMnyO2 still has the fatal weakness of poor cycle stability, limiting its further wide application. Bulk doping is an effective means to enhance the cycle stability, yet the electrochemical performances are very sensitive to the doping quantity. Here a facile method of co-precipitation is adopted to coat (Ni0.4Co0.2Mn0.4)1-xAlx(OH)2+x on precursor particles of NCM83. Al ions diffuse evenly in the NCM83 particles after sintering. The cells are operated at a high cut-off voltage of 4.5 V. The discharge capacity of NCM83 is 187.8 mAh g−1, and decays fast with cycles. The doped sample even exhibits a higher discharge capacity of 195 mAh g−1, and the capacity retention is improved to 83.8% after 200 cycles.