Effect Of Synthesis Technology And WMCNTs On The Electrochemical Performance Of LiFePO₄/C Cathode Material

Since the orderly olivine lithium iron phosphate in1997was first reported, it is widely regarded as the most promising cathode material for lithium batteries, because low cost, high safety, good environmental compatibility, long cycle life, innocuity and high specific capacity. Nevertheless, its relatively poor ionic and electronic conductivity limits its battery performance. Moreover, there exists the dramatic decrease in power at a high current density, limiting the electrochemical properties of materials.In order to improve the performance of lithium iron phosphate, this paper use a simple solid-states carbothermal reduction (CTR) synthesizing lithium iron phosphate and research doping carbon nanotubes modification.At the beginning, this paper uses cheap Fe2O3as raw material and uses CTR synthesizing lithium iron phosphate. The structures, morphological performances and electrochemical properties of LiFePO4were measured by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM), charge/discharge experiments, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The result indicates that LiFePO4cathode materials have excellent electrochemical performance under the synthesis technology:temperature of800℃, calcining time for20hours.In addition, effect of the morphological performances and electrochemical properties of LiFePO4, MWCNTs are doped modification, is study. Through X-ray diffraction (XRD), scanning electron microscopy (SEM), charge/discharge experiments, cyclic voltammetry (CV), charge-discharge test, and electrochemical impedance spectroscopy (EIS), The morphological performances and electrochemical properties of LiFePO4were measured in order to research doping carbon nanotubes modification. The result indicates that doping5wt%carbon nanotubes modification in LiFePO4has more superiority as the charge and discharge rate increased.