尖晶石锰酸锂表面化学镀钴研究

Preparation and Characterization of Co-coated LiMn_2O_4 by Electroless Plating

表面化学镀钴对LiMn2O4进行改性,X射线衍射、扫描电子显微镜、交流阻抗及恒电流充放电等技术检测和分析合成产物的物相、形貌及电化学性能。研究表明,与未镀钴的LiMn2O4相比,镀钴LiMn2O4粉末的X射线衍射峰强度有所变弱,样品颗粒表面粗糙,有许多小孔。化学镀钴后的LiMn2O4放电容量由改性前的123mA.h/g下降到改性后的112mA.h/g,室温下经20次循环后的容量保持率为96.8%,高于未镀钴的85.8%。55℃经20次高温循环后的比容量保持率为91.7%,远高于未镀钴的76.2%。表面镀钴后LiMn2O4的循环性能得到了显著改善。

The Co-coated LiMn2O4 powders were synthesized by the electroless plating.The phase,surface morphology and electrochemical properties of the synthesized powders were characterized with X-ray diffraction,scanning electron micrograph,electrochemical impedance spectroscopy and galvanostatic charge-discharge experiments.The Co-coated LiMn2O4 shows a coarse surface with a lot of holes.The specific capacity of Co-coated LiMn2O4 is 112 mA·h/g,which is slightly smaller than 123 mA·h/g for uncoated LiMn2O4.The capacity retention of Co-coated LiMn2O4 is 96.8% and 91.7% respectively after being cycled 20 times at room temperature and the temperature of 55 ℃,which are much higher than the values of 85.8% and 76.2% for the uncoated ones.