Liu Ruyan, Zhang Jiudi, Liu Siyu, Wang Xinyang, Qi Min, Dai Binting, Wang Yali, Ma Lin, Li Junjie, Yang Jinzheng, Jin Zhanshuang
College of Sciences, Hebei North University, Zhangjiakou, 075000, China.
Chemistry. 2024 Nov 21;30(65):e202403185. doi: 10.1002/chem.202403185. Epub 2024 Nov 5.
With high specific surface area, excellent polysulfide conversion activity, and fast electron/ion transfer at the interface, MXene-derived heterostructures can be employed as catalysts for lithium-sulfur (Li-S) batteries to accelerate sulfur redox kinetics and suppress shuttle effect. However, the preparation of MXene-derived heterostructures often requires high-temperature reactions, which can easily lead to the oxidation of MXene and sacrifice the electrical conductivity. Herein, a catalytic two-dimensional heterostructure (ZnS/MXene) was successfully synthesized via a mild method. The MXene skeleton retains the original nanosheet structure without oxidation. The in situ-grown ZnS nanospheres prevent the restacking of MXene nanosheets, which not only increases the active sites, but also guarantees channels for the fast passage of lithium ions. The interfacial built-in electric field further promotes electron/ion migration, thereby expediting the polysulfide conversion and suppressing the shuttle effect. Consequently, the batteries using ZnS/MXene modified separators exhibit a high initial discharge capacity of 1230 mAh g at 0.1 C and a low decaying rate of 0.082 % per cycle after 500 cycles at 0.5 C. This work offers a reference for the fabrication of MXene-based heterostructure in Li-S batteries.
凭借高比表面积、出色的多硫化物转化活性以及界面处快速的电子/离子转移，源自MXene的异质结构可作为锂硫（Li-S）电池的催化剂，以加速硫氧化还原动力学并抑制穿梭效应。然而，制备源自MXene的异质结构通常需要高温反应，这容易导致MXene氧化并牺牲其电导率。在此，通过一种温和的方法成功合成了一种催化二维异质结构（ZnS/MXene）。MXene骨架保留了原始的纳米片结构，未发生氧化。原位生长的ZnS纳米球可防止MXene纳米片重新堆叠，这不仅增加了活性位点，还保证了锂离子快速通过的通道。界面内建电场进一步促进电子/离子迁移，从而加速多硫化物转化并抑制穿梭效应。因此，使用ZnS/MXene改性隔膜的电池在0.1 C下表现出1230 mAh g的高初始放电容量，在0.5 C下循环500次后，每循环的低衰减率为0.082%。这项工作为锂硫电池中基于MXene的异质结构的制备提供了参考。
