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采用水热和溶胶-凝胶相结合的方法,制备了具有良好电化学性能的新型多壁碳纳米管-Na3V2(PO4)3(MWCNT-NVP)复合材料(MWCNT的质量分数为8.74%).通过场发射扫描电子显微镜表征可知,MWCNT分散在NVP纳米颗粒之间,并起到“电子导电线”的作用.与纯Na3V2(PO4)3相比,MWCNT-NVP具有更高的比容量和更优异的循环性能.在0.2C(35.2 mA·g-1)的电流密度下,3.0-4.5 V的电压范围内,MWCNT-NVP的初始比容量为82.2 mAh·g-1.循环100次以后,比容量为72.3 mAh·g-1.在1.0-3.0 V充放电时,MWCNT-NVP的初始容量为100.6 mAh·g-1.100次循环以后,其容量保持率高达90%.同时,交流阻抗测试表明,由于MWCNT的存在,MWCNT-NVP的导电性有了显著的提高.以上结果表明,MWCNT-NVP是一种良好的锂离子电池电极材料.
A novel multi-walled carbon nanotube-Na3V2 (PO4) 3 (MWCNT-NVP) composite with MWCNT mass fraction of 8.74% was prepared by hydrothermal method and sol-gel method. Characterization by field emission scanning electron microscopy shows that MWCNTs disperse between NVP nanoparticles and act as “electrically conductive wires.” MWCNT-NVP has a higher specific capacity than pure Na3V2 (PO4) 3 And more excellent cycling performance.The MWCNT-NVP has an initial specific capacity of 82.2 mAh · g-1 at a voltage range of 3.0-4.5 V at a current density of 0.2 C (35.2 mA · g-1) After that, the specific capacity was 72.3 mAh · g-1. The capacity retention of MWCNT-NVP was as high as 90% when the initial capacity of the MWCNT-NVP was 100.6 mAh · g-1.100 cycles at 1.0-3.0 V. Meanwhile, the AC impedance The results show that the MWCNT-NVP has a significant improvement in conductivity due to the presence of MWCNT.The above results show that MWCNT-NVP is a good lithium-ion battery electrode material.