Journal of Power Sources, Vol.423, 246-254, 2019
Enhancing structural stability unto 4.5 V of Ni-rich cathodes by tungsten-doping for lithium storage
Nickel-rich cathode material LiNi0.8Co0.1Mn0.1O2 has received widespread attention as the promising material for high energy density lithium-ion batteries. However, there still remains some formidable challenges for commercial application, of which the high-voltage cycling stability must be paid broad concerns because of the huge gap between the actual and ideal performance. Herein, a series of tungsten-doped LiNi0.8Co0.1Mn0.1O2 with enhanced capacity by pushing the cut-off potential to a high level (4.5 V) are investigated. It is found that the 0.5 mol% WO3 modified LiNi0.8Co0.1Mn0.1O2 (WNCM-0.5) displays optimal performance with an initial discharge capacity of 203.6 mAhg(-1), which is almost close to that of pristine LiNi0.8Co0.1Mn0.1O2 (205.9 mAhg(-1)) at 0.2C (1C = 200 mAhg(-1)), within the potential range of 2.8-4.5 V. Moreover, the capacity loss for WNCM-0.5 is 7.9% after testing for 100 cycles at 1C, much less than that of the pristine cathodes (15%). Improved electrochemical performance could be ascribed to the obstruction of impendence increase and discharge voltage decline, as well as suppression of structure collapse upon cycling.