柠檬酸含量对纳米正极材料LiCo_(0.05)Mn_(1.95)O_4的影响

Influence of citric acid contents on nano cathode material LiCo_(0.05)Mn_(1.95)O_4

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。

The content of the chelating agents have a great impact on the electrochecal properties of materials by the sol-gel method. Colalt-doped lithium manganese oxide spirei LiCo0.05Mn1.95O4 poweder was synthesized by acid sol-gel method. The influence of citric acid content on the structure and elecbochemical propedies of materials was investigated by XRD, SEM, constant current charge and discharge, electlochendcal impedance speclroscopy （EIS） and cyclic voltammetnj（CV） experiments. The chan3e-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 capacily of 120.7 and 118.2 mAh/g after 10 cycles, respectively, while at the rate l Ccunrent, the stable discharge specific capacity is about 80 mAh/g after 20 cycles. The SEM shows that the material is nanoscale.