材料期刊网

采用溶胶-凝胶法制备锂离子电池正极材料LiNi0.8Co0.15Al0.05O2,溶剂分别采用水、乙醇、乙二醇和丙三醇。通过TG/DSC进行样品的热性能分析,确定样品的烧结条件为550℃预处理6 h,750℃烧结24 h。XRD分析结果显示,采用有机溶剂制备的样品,018/110峰分裂明显,但向小角度偏移,说明样品的晶间距增大。SEM结果表明,采用有机溶剂制备的样品,平均颗粒尺寸0.4μm,小于采用水溶剂制备的样品颗粒尺寸0.5μm。采用乙醇与乙二醇为溶剂制备的样品出现了部分大尺寸的单晶颗粒。电化学性能测试结果表明,采用有机溶剂制备的样品的充放电性能要低于水作为溶剂的样品性能,但是采用乙醇作为溶剂制备的样品,首次放电容量(197.33 mAh/g)与水作为溶剂(200.66 mAh/g)制备的样品相当,并且在1C倍率下50次循环,容量保持率由水溶剂制备样品的87.1%增大至94.4%。大尺寸单晶颗粒的存在有利于NCA材料循环性能的提高。

Lithium ion battery cathode material LiNi0.8Co0.15Al0.05O2 was prepared by Sol-Gel, respectively, using water, ethanol, ethylene glycol, glycerol as a solvents. Through TG / DSC analysis of the thermodynamic properties, the sintered condition of the sample was selected as pre-treatment at 550℃for 6 h and then sintering at 750℃ for 24 h. XRD patterns show that the 018/110 peak of the samples prepared by organic solvent is splitted obviously, but the peak shifts to a small angle, which indicates that the lattice spacing increases. SEM results show that the average parti-cle size of the samples prepared by organic solvent is 0.4μm, which is smaller than that of the sample (0.5μm) pre-pared by using water. Some of the single crystals present in the sample prepared by using ethanol and ethylene glycol as solvent. The electrochemical performance test results show that the charge-discharge performance of samples prepared in the organic solvent is lower than that of the sample prepared in the water. However, the initial discharge capacity (197.33 mAh/g) of the samples prepared using ethanol as a solvent (200.66 mAh/g) is closed to that of the sample prepared by using water as solvent, and cycle performance has greatly improved at 1C rate. After 50 cycles at 1C rate, the capacity retention rate of the sample prepared by using water is increased from 87.1% to 94.4% as com-pared with the sample prepared by using ethanol. The presence of large crystal particle is beneficial to improve the cy-cle performance of the NCA material.