锂离子电池LiFePO4/Li3V2(PO4)3复合正极材料的制备及性能研究  

Preparation and properties of LiFePO4/Li3V2(PO4)3 composite cathode material for lithium-ion batteries

作　　者：秦显忠 蔡飞鹏 王波 蒋波 姜桂林 QIN Xian-zhong;CAI Fei-peng;WANG Bo;JIANG Bo;JIANG Gui-lin(Energy Institute,Qilu University of Technology(Shandong Academy of Sciences),Jinan 250014,China;School of Energy and Power Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250014, China)

机构地区：[1]齐鲁工业大学(山东省科学院)山东省科学院能源研究所,山东济南250014 [2]齐鲁工业大学(山东省科学院)能源与动力工程学院,山东济南250014

出　　处：《山东科学》2020年第5期67-72,83,共7页Shandong Science

基　　金：山东省重点研究发展计划(2017CXGC0502,2019GGX103038);山东省科学院国际科技合作项目(2019GHPY17)。

摘　　要：为了提高LiFePO4正极材料的离子导电性,采用液相共沉淀法与碳热还原法制备一系列质量配比的LiFePO4/Li3V2(PO4)3复合材料,通过X-射线衍射、扫描电镜、恒流充放电测试仪等分析测试手段测试样品。研究发现,m(LiFePO4):m(Li3V2(PO4)3)=6:4时复合材料形貌较为规则且结晶度较高,在0.1C,1.0C,2.0C,5.0C,10.0C倍率下放电比容量可达148,136,130.5,121.5,112.3 mA·h·g-1,1C倍率下循环100次容量保持率仍可达98.5%,有效地解决了LiFePO4离子电导率低的问题,推动了该复合正极材料在动力型锂离子电池中的应用。LiFePO4/Li3V2(PO4)3 composite cathode materials with a series of mass ratios were synthesized using the liquid-phase co-precipitation method and carbon thermal-reduction process to improve the electronic conductivity of LiFePO4 cathodes.X-ray diffraction,scanning electron microscopy,constant-current charge and discharge testing,and other analytical methods were used to analyze the phase composition,morphology,and electrochemical performance of the composites.When the mass ratio of LiFePO4 and Li3V2(PO4)3 was 6:4,the composite exhibited regular morphology,higher crystallinity,and the best electrochemical performance:the discharge capacity was 148,130.5,121.5,and 112.3 mA·h·g-1 at rates of 0.1C,1.0C,2.0C,5.0C,and 10.0C,respectively,and the capacity remained above 98.5%after 100 cycles at 1C.This effectively solves the problem of low conductivity of the LiFePO4 material and will accelerate its application in power lithium-ion batteries.

关 键 词：锂离子电池 正极材料 液相共沉淀法 倍率性能 循环性能 

分 类 号：TM912[电气工程—电力电子与电力传动]