采用环氧树脂为碳源制备出碳芯结构LiFePO4/C复合材料.利用X射线衍射、扫描电镜、透射电镜和X光电子能谱等分别对复合材料的晶体结构、表面形貌及表面成分进行表征,采用恒电流充放电和电化学阻抗方法研究试样的电化学性能.实验结果表明:碳芯结构复合材料是由无定形碳线和纳米LiFePO4颗粒组成.碳芯结构LiFePO4/C复合材料在15mA/g的电流密度下,首次放电容量达到166mAh/g,当电流密度增加到750mA/g,放电容量高达131mAh/g,经过50次循环后,容量保持率高达99.2%.
LiFePO4/C composite with carbon core structure was successfully synthesized by using epoxy resin as carbon source.The microstructure,morphology,surface composition of LiFePO4/C composite were characterized by X-ray diffraction(XRD),scanning electron microscope(SEM),transmission electron microscope(TEM) and X-ray photoelectron spectroscope(XPS).Their electrochemical properties were investigated in terms of galvanostatic charge-discharge and electrochemical impedance spectroscope(EIS) tests.The experimental results show that LiFePO4/C composite with carbon core structure is composed of amorphous carbon line core and nanometer LiFePO4 grains.The initial discharge capacity of LiFePO4/C composite is 166mAh/g at current density of 15mA/g.Its initial discharge capacity is 131mAh/g with capacity retention of 99.2% after 50 cycles at current density of 750mA/g.