以Mn_3O_4为锰源合成高性能LiMn_2O_4正极材料

Synthesis of High-performance LiMn_2O_4Cathode Material Using Mn_3O_4 as Mn Source

以Mn3O4为锰源,采用固相反应法,在较低的温度(650℃)制得尖晶石LiMn2O4正极材料。采用X射线衍射(XRD)、扫描电镜(SEM)、循环伏安和恒流充放电等技术对其相组成、微结构和电化学性能进行表征。结果表明该正极材料结晶良好,一次粒径约为150 nm。它的电化学性能,尤其是循环性能,明显优越于在较高温度合成的LiMn2O4。在电流密度为74 mA?g-1时,测得比容量为128 mAh?g-1,在1 480 mA?g-1时,比容量为105 mAh?g-1;在室温、148 mA?g-1充放电200次循环后,容量保持率为93%。

Spinel LiMn2O4 cathode material was obtained by a solid state reaction at a temperature as low as 650 ℃, with Mn3O4 as Mn source. Techniques of X-ray diffraction （XRD）, electronic scanning microscopy （SEM）, cyclic voltammetry and galvanostatic charge-discharge were employed to characterize its phase compositions, rnicrostructures and electrochemical performance. The results show that the cathode material obtained is well crystallized with a primary particle size of-150 nm. Its electrochemical performance, especially its cycling performance, is remarkably superior to that of LiMn2O4 cathode materials synthesized at elevated temperatures. Its specific capacity determined at current densities of 74 and 1 480 mA g-1 is 128 and 105 mAh. g-1; respectively. After cycled for 200 cycles at 148 mA. g-1 and room temperature, it still retains 93% of its initial capacity.