Li3V2-xMgx（PO4）3/C正极材料的制备及电化学性能研究  

Studies on the preparation and electrochemical performances of Li3V2-xMgx（PO4）3/C cathode materials

作　　者：张钰 ZHANG Yu(Department of Chemistry,College of Pharmacy,Xinjiang Medical University,Urumqi 830011,China)

机构地区：[1]新疆医科大学药学院化学教研室

出　　处：《化学研究与应用》2019年第11期2011-2016,共6页Chemical Research and Application

基　　金：新疆自治区自然科学基金项目(2017D01C231)资助;新疆医科大学校级科技创新重点资助项目(XYDCX201604)资助

摘　　要：通过溶胶-凝胶法制备出Mg2+掺杂Li3V2-xMgx(PO4)3/C(x=0,0.01,0.05,0.09)正极材料。采用X-射线衍射(XRD)、透射电镜(TEM)对材料的结构和形貌进行了表征和分析,通过恒流测试、循环伏安和交流阻抗测试对样品的电化学性能进行了表征,结果表明适量的掺杂能够显著提高材料的电化学性能。当倍率为0.2 C,充放电电压为2-4.3 V,材料Li3V1.95Mg0.05(PO4)3/C表现出最优的电化学性能,首次放电容量达到162.1 mAh·g^-1。经过不同倍率的充放电循环后,其初始容量保持率可达98.5%,表现出优异的电化学稳定性。Mg-doped cathode materials Li3V2-xMgx(PO4)3/C(x=0,0.01,0.05,0.09)were prepared by the sol-gel method.The microstructures and morphologies were analyzed by X-ray diffraction(XRD)and transmission electron microscopy(TEM),respectively.The electrochemical properties of the samples were tested by constant current tests,cyclic voltammetry and AC impedance tests,respectively.It was shown that the proper amount of Mg doping level importantly improved the electrochemical performance of the Li3V2(PO4)3/C material.The Li3V1.95Mg0.05(PO4)3/C composite displayed the best electrochemical property,with a specific discharge capacity of 162.1 mAh·g^-1 at 0.2 C,under the potential range of 2-4.3 V.After the charge and discharge process at different rates,the initial discharge capacity retention is 98.5%,and the material is shown to exhibit excellent electrochemical stability.

关 键 词：溶胶-凝胶 掺杂 电化学性能 Li3V2(PO4)3正极材料 

分 类 号：O614.5[理学—无机化学]