磷酸铁锂掺碳纳米管的电化学性能研究

Study on electrochemistry of LiFePO_4 doping with MWCNTs

用球磨法制备多壁碳纳米管掺杂LiFePO4的锂离子电池正极材料。X射线衍射(XRD)和扫描电子显微镜(SEM)测试表明,掺杂不会改LiFePO4橄榄石型晶体结构,碳纳米管连接于LiFePO4颗粒之间,起电桥作用,有利于提高LiFePO4电化学性能。研究不同管径碳纳米管掺杂对电极电化学性能的影响,结果表明管径越大电极材料的电化学性能越好。

LiFePO4/MWCNTs composite used as anode was synthesized by ball milling. XRD and SEM experiments demonstrate that MWCNTs don＇t change the olivine structure of LiFePO4 and that MWCNTs decentralized into the grains of LiFePO4 and working as electric bridge improves the electrochemical properties of LiFePO4. The electrochemical performance of the composite electrodes with different MWNTs contents were studied by button cell. The result indicates that the composite with largest diameter MWNTs exhibits the best electrochemical performance.