Significant Improvement of LiNi0.8Co0.1l0.05O2 Cat

研究领域：锂离子电池电极材料 交流阻抗频率范围：5000Hz - 0.1Hz The cyc领 performance of a LiNi0.8Co0.1l0.05O2 cathode at 60°C was substantially improved by direct SiO2 dry coating. The SiO2-coated cathode was obtained from firing of the mixture consisting of SiO2 nanoparticles and the cathode powders with a weight ratio of 99:1 at 700°C for 5 h. The first discharge capacity of the coated cathode was 172 mAh/g, whereas the uncoated one showed 182 mAh/g at 60°C. However, the coulombic efficiency of the coated sample was 95%, which was 2% higher than that of the uncoated sample. Moreover, the discharge capacities of the coated cathode at 60°C was about 2.5 times larger than those of the uncoated sample at rates of 0.5 and 1C, showing 146 and 109 mA/g, respectively. This capacity improvement at 60°C is related to the fact that the highly distributed Si element near the surface, as a type of solid solution with LiNi0.8Co0.1l0.05O2, diminishes the side reactions of the cathode and electrolyte at 60°C.