Li_3VO_4修饰富镍LiNi_(0.8)Co_(0.1)Mn_(0.1)O_2正极材料的电化学性能

Electrochemical performance of Li_3VO_4 modified Ni-rich LiNi_(0.8)Co_(0.1)Mn_(0.1)O_2 cathode materials

采用湿法融合技术及高温固相法合成Li_3VO_4包覆的LiNi_(0.8)Co_(0.1)Mn_(0.1)O_2正极材料。通过X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)等方法研究材料的结晶相、形貌、微观结构。研究表明,Li_3VO_4均匀地包覆在Li Ni0.8Co0.1Mn0.1O_2表面,未改变原材料的材料结构和形貌,包覆层厚度为1～2 nm。不同含量的Li_3VO_4对LiNi_(0.8)Co_(0.1)Mn_(0.1)O_2正极材料进行修饰研究表明,3%(质量)Li_3VO_4包覆的LiNi_(0.8)Co_(0.1)Mn_(0.1)O_2在1 C下100次循环后容量保持率为94.13%,具有最佳的倍率性能和循环性能。此外,循环伏安(CV)和交流阻抗(EIS)分析表明,Li_3VO_4能提高Li+电导率,抑制活性材料与电解液之间的副反应,提高材料的电化学性能。

The Li3VO4coated LiNi0.8Co0.1Mn0.1O2cathode material was synthesized by wet fusion technology and high temperature solid phase method.The crystalline phase,morphology and microstructure of materials were studied by X-ray diffraction(XRD),scanning electron microscope(SEM)and transmission electron microscope(TEM).The results show that Li3VO4is evenly coated on the surface of LiNi0.8Co0.1Mn0.1O2without changing the material structure and morphology of the raw materials.The coating thickness is1-2nm.The modification of LiNi0.8Co0.1Mn0.1O2cathode material with different content of Li3VO4shows that3%(mass)Li3VO4coated LiNi0.8Co0.1Mn0.1O2has a capacity retention rate of94.13%after100cycles under1C,which has the best multiplier performance and cycling performance.In addition,cyclic voltammetry(CV)and alternating current impedance(EIS)analysis show that Li3VO4can increase Li+conductivity,inhibit the side-effect between active material and electrolyte,and improve the electrochemical properties of materials.