Sulfur Cathodes Based on Conductive MXene Nanosheets for High-Performance Lithium-Sulfur Batteries
Sulfur Cathodes Based on Conductive MXene Nanosheets for High-Performance Lithium-Sulfur Batteries
复制标题
DOI：
10.1002/anie.201410174
复制
发表时间：
2015-03-23
影响因子：
16.6
通讯作者：
Nazar, Linda F.
中科院分区：
文献类型：
--
作者：
Liang, Xiao;Garsuch, Arnd;Nazar, Linda F.
锂硫电池是最有希望满足新兴储能需求的候选电池之一。在保持高硫含量的同时抑制多硫化物穿梭是其实用化发展面临的主要挑战。在这里，我们报告了2D早期过渡金属碳化物导电MXene相-据报道是令人印象深刻的超级电容器材料-也由于其固有的高潜在金属导电性和自功能化表面而用作优秀的硫电池主体。X射线光电子能谱研究表明，70wt%S/Ti2C复合材料具有稳定的长期循环性能，这是由于多硫化物物种与表面钛原子的强烈相互作用所致。该正极材料具有优良的循环性能，在5小时的充放电(C/5)倍率下，比容量接近1200 mA HG(-1)。在两小时的充放电(C/2)电流速率下，在400次循环中可实现80%的容量保持。
Lithium-sulfur batteries are amongst the most promising candidates to satisfy emerging energy-storage demands. Suppression of the polysulfide shuttle while maintaining high sulfur content is the main challenge that faces their practical development. Here, we report that 2D early-transition-metal carbide conductive MXene phases-reported to be impressive supercapacitor materials-also perform as excellent sulfur battery hosts owing to their inherently high underlying metallic conductivity and self-functionalized surfaces. We show that 70 wt% S/Ti2C composites exhibit stable long-term cycling performance because of strong interaction of the polysulfide species with the surface Ti atoms, demonstrated by X-ray photoelectron spectroscopy studies. The cathodes show excellent cycling performance with specific capacity close to 1200 mA hg(-1) at a five-hour charge/discharge (C/5) current rate. Capacity retention of 80% is achieved over 400 cycles at a two-hour charge/discharge (C/2) current rate.