利用不同的方法合成了Na3 V2(PO4)3/C复合材料,通过X射线衍射、红外光谱、扫描电镜、循环伏安、交流阻抗等方法对Na3 V2(PO4)3/C材料进行了结构表征及性能测试.通过改变合成方法,考察了不同合成路径对于材料结构、微观形貌及电化学性能的影响.研究发现,利用水热法合成的 Na3 V2(PO4)3/C 复合材料的颗粒呈类球形,粒径尺寸为50 nm.电化学性能测试表明,0．1 C 倍率下,其首次放电比容量接近理论值,达到117．3 mAh/g,50次循环后容量保持率为97．3％.2 C倍率下,其放电容量仍能达到81．6 mAh/g,循环10次后容量未见衰减.
In this study,the Na3 V2 (PO4 )3/C composites were successfully synthesized by different methods. The structure and electrochemical properties of Na3 V2 (PO4 )3/C composites were investigated by Fourier trans-form infrared spectrum,X-ray diffraction,scanning electron microscope,cyclic voltammetry and electrochemi-cal impedance spectroscopy.The effect of synthetic method on the structure and performance of the cathode ma-terial was investigated.Na3 V2 (PO4 )3/C composite with a particle size of 50 nm was successfully synthesized via a hydrothermal method.This study demonstrates that growth of large particles can be effectively inhibited in the hydrothermal method,and the composite show a smaller and more uniform particle size.The electrochemi-cal tests show that the initial discharge capacity of the composite was 117.3 mAh/g at 0.1 C rate and the capaci-ty retention rate was 97.3% after 50 cycles.Even at a high charge-discharge rate of 2 C,it still delivered a dis-charge capacity of 8 1 .6 mAh/g and maintained this capacity after 1 0 cycles.
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