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为了改善锂硫电池的循环性能,以纸纤维为基体,多壁碳纳米管(MWCNTs)为导电剂,采用真空抽滤法制得MWCNTs导电纸,并将MWCNTs导电纸作为正极集流体代替铝箔应用于锂硫电池。对MWCNTs导电纸进行了形貌结构表征和电化学性能测试,并对循环后的MWCNTs导电纸电极进行EDS检测。结果显示,MWCNTs均匀地附着在纸纤维基体上,多空隙的MWCNTs导电纸三维结构明显。采用MWCNTs导电纸作集流体的锂硫电池在0.05C和1C倍率充放电下循环30次,比容量分别保持615mAh/g、496mAh/g,库伦效率达97.5%以上,且电荷转移电阻在循环后降低。EDS元素分析结果证实MWCNTs导电纸对多硫化锂有吸附作用,从而一定程度抑制了锂硫电池的穿梭效应。因此,以MWCNTs导电纸作为集流体能有效增加活性物质硫的负载量和接触面积,使锂硫电池具有良好的循环稳定性和库伦效率性能。
In order to improve the cycle performance of lithium-sulfur batteries, multi-walled carbon nanotubes (MWCNTs) were used as conductive materials based on paper fibers. MWCNTs conductive paper was prepared by vacuum filtration and MWCNTs conductive paper was used as positive electrode current collector instead of aluminum foil Lithium sulfur battery. The morphology and electrochemical properties of MWCNTs conductive paper were tested. EDS of MWCNTs conductive paper electrode was carried out. The results show that the MWCNTs are uniformly attached to the paper fiber matrix, and the three-dimensional structure of the MWCNTs multi-gap conductive paper is obvious. The lithium-sulfur battery using MWCNTs conductive paper as the current collector circulated for 30 times at a charge and discharge rate of 0.05C and 1C, respectively, and the specific capacity was maintained at 615mAh / g and 496mAh / g respectively. The coulombic efficiency was over 97.5% reduce. EDS elemental analysis confirmed that MWCNTs conductive paper adsorption of lithium polysulfide, which to some extent inhibited the shuttle effect of lithium-sulfur batteries. Therefore, MWCNTs conductive paper as the collector can effectively increase the sulfur loading of the active material and the contact area, so that the lithium-sulfur battery has good cycle stability and coulomb efficiency.