钒离子改性MXene的制备及其在锂硫电池中的应用研究

Preparation of MXene Modified by Vanadium Ion and Their Application in Lithium-Sulfur Batteries

利用化学刻蚀后得到的MXene(MX)片层具有大量阴离子官能团的特点,采用喷雾干燥技术,设计并合成了钒离子改性MXene(MX-VN)材料用于锂硫电池正极。MXene的优异导电性可以提高硫正极整体的导电性,同时原位构建的MX-VN界面可以提高对多硫化物的吸附效果和催化能力,提高硫的利用率。实验结果表明,采用MX-VN/S为正极的锂硫电池在0.1 C下的放电容量高达1438 mAh/g,且在0.5 C下循环200次以后容量保持率高达77.5%,电池性能明显提升。

The MXene(MX)sheet obtained by chemical etching has a large number of anionic functional groups.Based on the spray drying technology,the MXene modified by vanadium ion(MX-VN)material was designed and synthesized for the cathode of lithium-sulfur batteries(LSBs).The excellent conductivity of MXene could improve the overall conductivity of the sulfur cathode.At the same time,the in-situ constructed MX-VN interface could improve the adsorption effect and catalytic ability of polysulfides,meanwhile improve the utilization rate of sulfur.The experimental results showed that the discharge capacity of the LSBs with MX-VN/S as the cathode was as high as 1438 mAh/g at 0.1 C,and the capacity retention rate was as high as 77.5% after 200 cycles at 0.5 C.The performance of the battery was significantly improved.