异质原子掺杂金属有机框架衍生多孔碳宿主材料在锂硫电池中的应用

Application of Porous Carbon Host Materials Derived from Heterogeneous Atom Doped Metal-Organic Framework in Lithium-Sulfur Batteries

利用尿素和ZIF-67为原料,通过分步碳化得到了氮氧掺杂多孔碳(N-O-ZIF),相比于未掺杂制备的多孔碳(ZIF)相比,N-O-ZIF含有更多的氮元素,可以为锚定多硫化物提供更多的活性位点,更好地抑制穿梭效应,提高硫的利用率。以N-O-ZIF为硫宿主材料的锂硫电池表现出了优异的电化学性能:S@N-O-ZIF复合正极在2 A·s^(-1)电流密度下的初始放电比容量高达780.0 mAh·g^(-1),循环500圈后,容量保持率为78.65%,圈均容量衰减率为0.043%。

In this paper,N,O atoms were co-doped in ZIF-67 to form a porous carbon material N-O-ZIF using urea and ZIF-67 as the dopant and raw materials,respectively.Compared with ZIF that was derived from sole ZIF-67,N-O-ZIF contains more nitrogen elements to form abundant active sites for polysulfide adsorption,which can effectively inhibit the shuttle effect and improve the utilization rate of sulfur.Lithium-sulfur batteries containing N-OZIF as the sulfur host material show excellent electrochemical performance which delivered the high initial discharge capacity of 780.0 mAh·^(g-1)at 2 A·s^(-1)and an ultralow capacity decay rate of 0.043%in 500 cycles.