碳源对碳热法制备LiFePO_4/C复合电极材料性能的影响  

Influence of Carbon Sources on the Electrochemical Performance of LiFePO_4/C Composite Electrode Materials Prepared by Carbothermal Reduction Method

作　　者：吴浩[1] 卢建树[1] 

机构地区：[1]浙江工业大学材料化学实验室,浙江杭州310014

出　　处：《浙江化工》2012年第8期32-35,共4页Zhejiang Chemical Industry

摘　　要：以廉价的Fe2O3为铁源,(NH4)H2PO4为磷源,Li2CO3为锂源,分别以乙炔黑、葡萄糖、PEG6000为还原剂和碳源,采用碳热还原法制备了LiFePO4/C复合材料。X射线衍射(XRD)分析表明用三种碳源都合成了橄榄石结构的LiFePO4。扫描电子显微镜(SEM)分析显示,以PEG6000为碳源合成的LiFePO4/C复合材料粒径较小,较均匀,且有较好的碳包覆。以充放电曲线、循环性能和交流阻抗等测试研究了材料的电化学性能,结果表明,以PEG6000为碳源合成的材料的电化学性能较好,0.1C、1C下首次放点比容量分别为144.7 mAh/g、132 mAh/g。LiFePO4/C composite electrode materials was synthesized by carbothermal reduction method,which using cheap Fe2O3 as iron source,(NH4)H2PO4 as phosphate source,Li2CO3 as lithium source,and acetylene black or glucose or PEG6000 as carbon source.The XRD results show that all LiFePO4/C materials are olivine-type phase.SEM observation show that the LiFePO4/C using PEG6000 as carbon source has smaller grain size,more uniform grain size distribution and much better carbon coating.The galvanostatic charge-discharge tests,cyclic V-A tests and EIS analyses were used to investigate the electrochemical properties of the samples.The results show that the LiFePO4/C using PEG6000 as carbon source has superior electrochemical performance.Its first discharge capacity was 144.7 mAh/g and 132 mAh/g at 0.1 C and 1 C rate respectively.

关 键 词：磷酸铁锂 碳热法 碳源 电化学性能 

分 类 号：TM912[电气工程—电力电子与电力传动]