3D amorphous carbon and graphene co-modified LiFePO_4 composite derived from polyol process as electrode for high power lithium-ion batteries  

作　　者：Guan Wu Ran Ran Bote Zhao Yujing Sha Chao Su Yingke Zhou Zongping Shao 

机构地区：[1]State Key Laboratory of Materials-Oriented Chemical Engineering,College of Chemistry & Chemical Engineering,Nanjing University of Technology [2]Ningde Amperex Technology Limited [3]Department of Chemical Engineering,Curtin University,Perth,WA 6845,Australia

出　　处：《Journal of Energy Chemistry》2014年第3期363-375,共13页能源化学（英文版）

基　　金：supported by the National Science Foundation for Distinguished Young Scholars of China(No.51025209);the National Nature Science Foundation of China(No.21103089);the Key Projects in Nature Science Foundation of Jiangsu Province(No.BK2011030)

摘　　要：Amorphous carbon and graphene co-modified LiFePO4 nanocomposite has been synthesized via a facile polyol process in connection with a following thermal treatment.Various characterization techniques,including XRD.Mossbauer spectra,Raman spectra,SEM,TEM,BET,O2-TPO,galvano charge-discharge,CV and EIS were applied to investigate the phase composition,carbon content,morphological structure and electrochemical performance of the synthesized samples.The effect of introducing way of carbon sources on the properties and performance of LiFePO4/C/graphene composite was paid special attention.Under optimized synthetic conditions,highly crystalized olivine-type LiFePO4was successfully obtained with electron conductive Fe2P and FeP as the main impurity phases.SEM and TEM analyses demonstrated the graphene sheets were randomly distributed inside the sample to create an open structured LiFePO4 with respect to graphene,while the glucosederived carbon mainly coated over LiFeP04 particles which effectively connected the graphene sheets and LiFePO4 particles to result in a more efficient charge transfer process.As a result,favorable electrochemical performance was achieved.The performance of the amorphous carbon-graphene co-modified LiFePO4 was further progressively improved upon cycling in the first 200 cycles to reach a reversible specificcapacity as high as 97 mAh·g-1 at 10 C rate.Amorphous carbon and graphene co-modified LiFePO4 nanocomposite has been synthesized via a facile polyol process in connection with a following thermal treatment.Various characterization techniques,including XRD.Mossbauer spectra,Raman spectra,SEM,TEM,BET,O2-TPO,galvano charge-discharge,CV and EIS were applied to investigate the phase composition,carbon content,morphological structure and electrochemical performance of the synthesized samples.The effect of introducing way of carbon sources on the properties and performance of LiFePO4/C/graphene composite was paid special attention.Under optimized synthetic conditions,highly crystalized olivine-type LiFePO4was successfully obtained with electron conductive Fe2P and FeP as the main impurity phases.SEM and TEM analyses demonstrated the graphene sheets were randomly distributed inside the sample to create an open structured LiFePO4 with respect to graphene,while the glucosederived carbon mainly coated over LiFeP04 particles which effectively connected the graphene sheets and LiFePO4 particles to result in a more efficient charge transfer process.As a result,favorable electrochemical performance was achieved.The performance of the amorphous carbon-graphene co-modified LiFePO4 was further progressively improved upon cycling in the first 200 cycles to reach a reversible specificcapacity as high as 97 mAh·g-1 at 10 C rate.

关 键 词：cathode material lithium iron phosphate GRAPHENE amorphous carbon polyol process 

分 类 号：O613.71[理学—无机化学] TM912[理学—化学]