收录:
摘要:
Nano-sized Li1.26Fe0.22Mn0.52O2 (LFMO) cathode material coated with conducting polypyrrole (PPy) was successfully synthesized by simple chemical oxidative polymerization. The crystal structure of the sample was examined by X-ray diffraction (XRD), and the morphology and micro-structure were observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The elemental mapping and Fourier transform infrared spectrometer results demonstrated that the conductive network of PPy was present in the composites and PPy was uniformly distributed on the LFMO particles. The electrochemical properties of all of the samples were investigated by galvanostatic charge-discharge test and electrochemical impedance spectroscopy (EIS) analysis, which showed that the PPy on the surface significantly decreased the charge-transfer resistance of LFMO. LFMO coated with mass ratio of 2% PPy (LFMO-2%PPy) exhibited excellent rate performance and good cycle stability. The initial discharge capacity was 206 mAh.g(-1) at the 1C rate, and the initial coulombic efficiency was 87%. After 50 cycles at 1C and 2C, the capacity stabilized at 131 and 139 mAh.g(-1), respectively.
关键词:
通讯作者信息:
电子邮件地址: