高温还原GO制备LiFePO_4/石墨烯复合正极材料及表征

通过对氧化石墨烯(GO)进行微观调控处理得到少层GO。采用喷雾干燥再高温改性的方法制备LiFePO_4/石墨烯锂离子电池复合正极材料;GO还原后即可得到石墨烯,其优良的导电性可以提高LiFePO_4的电子传输能力。通过X射线衍射(XRD)、红外光谱(FTIR)、扫描电镜(SEM)、透射电镜(TEM)和电化学测试技术等方法对复合材料的结构、形貌及电化学性能进行表征。石墨烯的复合使材料颗粒间构建空间三维导电网络,提高了电解质/电极材料界面的电荷转移速率,改善了LiFePO_4的电化学性能。电化学测试结果表明,在0.1C时LiFePO_4的放电比容量为155mAh/g,LiFePO_4/石墨烯复合材料的放电比容量为164mAh/g;1C和2C倍率时,LiFePO_4/石墨烯复合材料的放电比容量分别为140,119mAh/g。

Preparation and Characterization of LiFePO 4/Graphene Composite Cathode Materials by High Temperature Reduction GO

Micro layer of GO was obtained by micro adjustment and control .LiFePO4/graphene com-posite cathode materials were synthesized using a spray drying followed by high temperature reduction modification method ,to improve conductivity of LiFePO4 with excellent conductivity of graphene . The structure ,morphology and electrochemical performance of the composite materials were charac-terized by XRD ,FTIR ,SEM ,TEM and electrochemical measurement technologies .The three-di-mensional conductive network was constructed by graphene composite in material particles ,which can improve the charge transfer rate of the interface of electrolyte/electrode materials and the electrochem-ical performance of LiFePO4 .The results show that the discharge specific capacity of LiFePO 4 without graphene is only 155mAh/g ,while the discharge specific capacity of LiFePO4/graphene is 164mAh/g at 0 .1C .The discharge specific capacity of LiFePO4/graphene is 140 ,119mAh/g at 1 ,2C ,respectively.