Mitigating Li_(2)S agglomeration in lithium-sulfur batteries with hierarchically structured CNT/Ni-Ni_(0.85)Se sulfur hosts  

抑制Li_(2)S团聚的高效硫宿主:分等级结构CNT/Ni-Ni_(0.85)Se

作　　者：Yonghui Xie Fan Wu Wenrui Zheng Hong Zhang Xinghui Wang 谢永辉;吴燔;郑文瑞;张红;王星辉

机构地区：[1]College of Physics and Information Engineering,Institute of Micro-Nano Devices and Solar Cell,Fuzhou University,Fuzhou 350108,China [2]Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering,Changzhou 213000,China

出　　处：《Science China Materials》2025年第4期1100-1108,共9页中国科学(材料科学)(英文版)

基　　金：supported by the National Natural Science Foundation of China(U22A20118);the Natural Science Foundation of Fujian Province(2023J01400)。

摘　　要：The development of sulfur host materials with high catalytic activity to tackle the shuttling effect of polysulfides and their slow conversion kinetics is a prospective strategy for improving the performance of lithium-sulfur batteries.However,it may result in excessively thick Li_(2)S films that cover the entire electrode structure,consequently weakening the functionalization effect of the sulfur host.Herein,we developed a hierarchical structured sulfur host material composed of a three-dimensional composite conductive network of carbon nanotubes and Ni nanoparticles,along with Ni_(0.85)Se nanosheets grown on its surface.The synergistic effects of hierarchical structure and conductive network accelerate the electron and ion transport,mitigate the volume expansion during lithiation,enhance the conversion kinetics of polysulfides,and importantly prevent the agglomeration of thick Li_(2)S films,which results in a significant improvement in the electrochemical performance of the sulfur cathode.The developed CC@CNT/Ni-Ni_(0.85)Se-S exhibits excellent rate performance and long-term stability,achieving a discharge-specific capacity of 965 mA h g^(-1) at 3 C and maintaining a discharge-specific capacity of 789 mA h g^(-1) even after 300 cycles at 1 C.Notably,the capacity retention rate is as high as 92.9%for 100 cycles at 0.1 C,even with a high sulfur loading of 4.0 mg mg^(-2).This work not only effectively mitigates the agglomeration of Li_(2)S film but also offers a novel design approach for the practical application of high-energy-density lithium-sulfur batteries.通过设计具有高催化活性的硫宿主材料来解决多硫化物的穿梭效应及其缓慢的转化动力学,是提升锂硫电池性能的有效策略.然而,传统设计可能导致较厚的Li_(2)S覆盖整个电极结构,从而削弱硫宿主的催化效果.本研究中,我们开发了一种新型分等级结构硫宿主材料,该材料由碳纳米管与镍纳米颗粒构建的三维复合导电网络,以及生长在其表面的Ni_(0.85)Se纳米片组成.分等级结构与导电网络的协同作用加速了电子和离子的传输,缓解了锂化过程中的体积膨胀,显著增强了多硫化物的转化反应动力学,并有效抑制了Li_(2)S的团聚现象,从而显著提升了硫正极的电化学性能.所开发的CC@CNT/Ni-Ni_(0.85)Se-S正极表现出优异的倍率性能和循环稳定性,在3 C倍率下实现了965 mA h g^(-1)的放电比容量,并在1 C倍率下经过300次循环后仍保持789 mA h g^(-1)的放电比容量.此外,即使在4.0 mg cm^(-2)的高硫负载下,该硫正极在0.1 C下经过100次循环的容量保持率仍高达92.9%.本研究不仅有效缓解了Li_(2)S的团聚问题,同时也为高能量密度锂硫电池的实际应用提供了一种全新的设计思路.

关 键 词：hierarchical structure carbon nanotube metal selenide catalysis lithium polysulfides lithium-sulfur batteries 

分 类 号：TM912[电气工程—电力电子与电力传动]