钠源对正极材料Na3V2（PO4）3性能的影响

采用溶胶凝胶-高温固相法，用不同的钠源制备NASICON结构钠离子电池正极材料Na₃V₂（PO₄）₃.借助扫描电子显微镜（SEM），X射线衍射分析（XRD），电池测试系统及电化学工作站对制备的Na₃V₂（PO₄）₃结构，形貌，电性能和内阻进行表征.研究结果表明，以Na₂CO₃为钠源合成Na₃V₂（PO₄）₃有更好的颗粒尺寸，形貌结构完整，充放电性能及循环稳定性更好，阻抗也较小；在2.5~4.0 V电压范围内，以0.2 C进行充放电，首次放电比容量达到110.8 mAh/g，50次循环后容量保持率为85.1 %. 

Effect of sodium source on electrochemical performance of Na3V2(PO4)3 cathode material

Na₃V₂(PO₄)₃ structure cathode material of sodium ion battery of NASICON was synthesized under different sodium source via sol-gel and high temperature sintering method. The morphology, crystal structure, electrochemical performance and electrochemical impendance spectroscopy for Na₃V₂(PO₄)₃ cathode material were characterized and tested by means of scanning electron microscopy (SEM), powder X-ray diffraction (XRD), galvanostatic charge-discharge tests and electrochemical workstation. The results show that Na₂CO₃ as a sodium source synthesized Na₃V₂(PO₄)₃ has batter particle size, morphology and structure integrity. The best electrochemical performance and the smallest internal impedance are also obtained. The initial discharge specific capacity of the material is as high as 110.8 mAh/g at 0.2 C within the voltage range of 2.5~4.0 V, the capacity retention ratio is 85.1 % after 50 cycles.