柠檬酸含量对纳米正极材料LiCo0.05Mn1.95O4的影响

在溶胶凝胶法中,螯合剂的含量对材料的性能有较大的影响。采用柠檬酸溶胶凝胶法制备了尖晶石掺钴锰酸锂LiCo0.05Mn1.95O4粉末。利用X射线衍射光谱法(XRD)、扫描电子显微镜法(SEM)、恒流充放电、电化学阻抗(EIS)、循环伏安(CV)等分析方法研究了柠檬酸含量对材料的结构和电化学性能的影响。充放电结果表明,当柠檬酸和总金属离子摩尔比为1∶1时制备出的材料具有良好的电化学性能;在3.0～4.3 V之间进行充放电,0.1 C下,材料首次放电比容量达到120.7 mAh/g,循环10次后保持在118.2 mAh/g,1 C下循环20次后放电比容量保持在80 mAh/g左右。SEM表明材料是纳米级别。

Influence of citric acid contents on nano cathode material LiCo0.05Mn1.95O4

The content of the chelating agents have a great impact on the electrochemical properties of materials by the sol-gel method.Cobalt-doped lithium manganese oxide spinel LiCo0.05Mn1.95O4 powder was synthesized by citric acid sol-gel method.The influence of citric acid content on the structure and electrochemical properties of materials was investigated by XRD,SEM,constant current charge and discharge,electrochemical impedance spectroscopy(EIS) and cyclic voltammetry(CV) experiments.The charge-discharge results show that the material possesses good electrochemical properties when the molar ratio of citric acid to total metal ion is 1∶1;at the rate of 0.1 C current and cutoff voltage of 3.0-4.3 V,LiCo0.05Mn1.95O4 powder possesses the initial and stable discharge specific capacity of 120.7 and 118.2 mAh/g after 10 cycles,respectively,while at the rate 1 C current,the stable discharge specific capacity is about 80 mAh/g after 20 cycles.The SEM shows that the material is nanoscale.