碳芯结构LiFePO_4/C复合材料的表征及电化学性能  

Characterization and Electrochemical Properties of LiFePO_4/C Composite with Carbon Core Structure

作　　者：陈晗[1] 龚文强[1] 刘友良[1] 刘建华[1] 

机构地区：[1]湖南工业大学冶金工程学院,株洲412000

出　　处：《无机材料学报》2010年第5期480-484,共5页Journal of Inorganic Materials

基　　金：国家自然科学基金(50972044);湖南省自然科学基金(09JJ5010);湖南省教育厅优秀青年项目(09B024)

摘　　要：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.

关 键 词：LIFEPO4 复合材料 碳芯结构 电化学性能 

分 类 号：TM912[电气工程—电力电子与电力传动]