镍钴酸锂的制备与电性能研究

以共沉淀法制得前驱体Ni0.8Co0.2(OH)2,再与LiOH.H2O混合通氧气于600℃恒温15h得到LiNi0.8Co0.2O2。X射线衍射分析表明合成的材料LiNi0.8Co0.2O2具有规整的-αNaFeO2层状结构。SEM表明材料颗粒呈类球体,大小均一。以0.1C电流充放电,首次放电比容量为176mA.h/g,循环20次后容量大幅度衰减。交流阻抗图谱表明材料充电态的电化学阻抗明显低于放电态的电化学阻抗。

Preparation and Electrochemistry Performance of LiNi0.8Co0.2O2 Cathode Material

Ni_(0.8)Co_(0.2)(OH)_2 powders were prepared via a co-precipitation method. LiNi_(0.8)Co_(0.2)O_2 powders was synthesized by sintering the Ni_(0.8)Co_(0.2)(OH)_2 and LiOH·H_2O in oxygen at 600℃ for 15h. XRD results show the material LiNi_(0.8)Co_(0.2)O_2 with order α-NaFeO_2 layer structure. SEM photos show the materials are spherical with the same particle size. Electrochemical test shows initial discharge capacity of 176 mAh·g~(-1) at the 0.1C rate, and capacity decreases largely after cycled 20 times. The electrochemical impedance spectroscopy diagram shows that the material's electrochemical impedance in the charged state is lower than state of discharged.