Elevated rate and cycling performance of nickel-rich single-crystal at high voltage enabled by Al/Ce co-doping

The large-scale application of nickel-rich ternary cathode materials is still limited by their inherent defects such as structural stability, cycling and rate performance. Herein a novel single-crystalline nickel-rich ternary cathode material dual-doped with Al and Ce is deliberately designed. Both of them are evenly distributed in the materials and an α-LiAlO2 layer evolves on the surface, which largely alleviate the corrosion from the electrolyte and facilitate the Li+ diffusion. Furthermore, the TM-O is partially replaced to form the Al–O and Ce–O bonds, which can reduce the degree of Li+/Ni2+ mixing and then stabilize the layered structure to certain extent. The dual-doped single-crystal nickel-rich ternary cathode material shows superior cycle stability and large-current discharge capacity to the undoped counterpart. After 100 cycles at 1C and a high cutoff voltage of 4.5 V, the target material yields a specific capacity of 160.95 mA h g−1, with a capacity retention of up to 85.38 %. More importantly, the α-LiAlO2-coated layer significantly facilitates the rate performance with a specific capacity of 164.5 mA h g−1 at 10C. The dual-doping strategy in this work provides a feasible pathway to improve the electrochemical performance of nickel-rich single-crystalline ternary cathode material.