LiNi_(0.8)Co_(0.2)O_2的制备与修饰

Synthesis and modification of LiNi_(0.8)Co_(0.2)O_2

由LiOH·H2O、NiO、Co2O3高温固相合成LiNi0 8Co0 2O2,并对制得的样品进行表面修饰.对所得产物进行了X光电子能谱、扫描电镜和X射线衍射测试,用合成的材料组装成电池进行充放电容量测试.实验结果表明:应用此工艺制备的LiNi0 8Co0 2O2具有高的充放电比容量,分别为184 8mA·h·g-1和160 7mA·h·g-1。包覆后初次充放电比容量分别为168 7mA·h·g-1和157 6mA·h·g-1.容量有所下降,但循环性能提高,说明表面修饰可以有效地抑制正极材料与电解液之间的恶性相互作用,能改善材料的循环性能.

Layered and highly crystalline LiNi_(0.8)Co_(0.2)O_2 was prepared by heating a mixture of lithium hydroxide, nickel oxide and cobalt oxide at high temperature. The sample was modified by surface treatment. Experiments of XPS, SEM and XRD were carried out. The original charging and discharging capacities of the batteries made from LiNi_(0.8)Co_(0.2)O_2 as the cathode materials were as high as about 184.8 mA·h·g^(-1) and 160.7 mA·h·g^(-1) respectively. The original charging and discharging capacities of coated LiNi_(0.8)Co_(0.2)O_2 were as high as 168.7 mA·h·g^(-1)and 157.6 mA·h·g^(-1) respectively. The capacities decreased after coating but the cycling performance was improved. The surface modification is concluded to inhabit the harmful interaction between cathode materials and electrolyte and to improve the cycling performance of cathode materials for lithium ion battery effectively.