Jianguo Duan

One-step liquid-phase reaction to synthesize LiNi 0.8 Co 0.15 Al 0.05 O 2 cathode material

AbstractnLiNi0.8Co0.15Al0.05O2 cathode material in lithium-ion batteries has been synthesized in a facile one-step liquid-phase reaction. The effects of sintering on the structural and electrochemical properties of LiNi0.8Co0.15Al0.05O2 are investigated. X-ray diffraction (XRD) test and XRD Rietveld refinement results indicate that LiNi0.8Co0.15Al0.05O2 cathode material prepared by one-step liquid-phase reaction is a hexagonal phase with low Li/Ni mixing degree. Scanning electron microscope and energy-dispersive spectrometer are applied to investigate the morphology of the samples and the distribution of metal ions, respectively. Transmission electron microscope measurement shows good crystallinity with well-fined lattice fringes corresponding to (003) planes. The surface information of the samples is investigated by X-ray photoelectron spectroscopy. Electrochemical data demonstrate that the sample sintered at 790xa0°C exhibits the best electrochemical performance. The sample shows a high initial discharge capacity of 193.5xa0mAhxa0g−1 at 0.2xa0C and an accepted cycle performance (84.7% capacity retention after 100 cycles). In addition, it displays outstanding rate capacity (152.5xa0mAhxa0g−1 at a rate of 10xa0C). The lithium-ion diffusion coefficients are obtained by different methods. The results of this paper provide a facile method to synthesize Ni-rich layered oxides for lithium-ion batteries.