Effects of W-doping on precursor growth of LiNi0.88Co0.09Mn0.03O2 and its electrochemical performance

Abstract

W-doped LiNi0.88Co0.09Mn0.03O2 cathodes were fabricated by using W-doped precursors. X-ray diffraction indicates that W-doping suppresses the crystal growth of the precursor along the direction perpendicular to c-axis. Scanning electron microscopy results show that the primary particles of the cathode become finer with the increase of W-doping amount. Electrochemical measurements prove the merits of the W-doped cathodes. The one with 0.4 wt.% W-doping shows significantly improved electrochemical properties compared with the pristine one. After 100 charge–discharge cycles at a high rate of 10C, it exhibits capacity retentions of 94.68% and 89.63% at 25 and 45 °C, respectively. The intergranular cracks after cycles are also suppressed by W-doping. Hence, profiting from the synergistic effect of component regulation and microstructure engineering by W-doping, the Li+ diffusion kinetics is boosted, and the structural stability is enhanced.