Effects of W-doping on precursor growth of LiNi0.88Co0.09Mn0.03O2 and its electrochemical performance
(1. Guangxi Key Laboratory of Electrochemical and Magneto-chemical Functional Materials, College of Chemistry and Bioengineering, Guilin University of Technology, Guilin 541004, China;
2. Zhejiang Power New Energy Co., Ltd., Zhuji 311899, China;
3. School of Metallurgy and Environment, Central South University, Changsha 410083, China;
4. School of Materials Science and Engineering, Hainan University, Haikou 570228, China)
2. Zhejiang Power New Energy Co., Ltd., Zhuji 311899, China;
3. School of Metallurgy and Environment, Central South University, Changsha 410083, China;
4. School of Materials Science and Engineering, Hainan University, Haikou 570228, China)
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.
Key words: W-doping; precursor growth; structural stability; cycle life; lithium-ion batteries