摘要
锂硫电池(LSBs)的实际应用受到硫利用率低、严重的穿梭效应和缓慢的氧化还原反应的限制.本工作通过使用新型莫特-肖特基异质结构对隔膜进行改性的策略有效地缓解上述问题.具体而言,这种特殊结构通过导电聚合物聚吡咯(PPy)在Bi_(2)MoO_(6)纳米片表面原位聚合形成Bi_(2)MoO_(6)-PPy纳米片来合成.基于Bi_(2)MoO_(6)-PPy纳米片的强吸附效应、高催化活性和内置电场,这种新型异质结构可以降低多硫化物上的氧化还原能垒.使用由Bi_(2)MoO_(6)-PPy纳米片改性的功能隔膜组装的电池显示出良好的循环稳定性,在2 C下500次循环中,每次循环的容量衰减低至0.045%.此外,即使在高硫负载(7.5 mg cm^(-2))下,电池在80次循环后仍显示出6.3mA h cm^(-2)的面积容量.因此,Bi_(2)MoO_(6)-PPy纳米片改性隔膜(Bi_(2)MoO_(6)-PPy@PP隔膜)有效地抑制了穿梭效应,为锂硫电池高效催化剂的应用提供了有效策略.
The low sulfur usage,strong shuttle effect,and dilatory redox processes limit the practical application of lithium-sulfur batteries(LSBs).The method of separator modification with a unique Mott-Schottky heterostructure used in this work significantly alleviates these issues.This unique structure is synthesized by in situ polymerizing the conductive polymer polypyrrole(PPy)on the surface of Bi_(2)MoO_(6)nanosheets to form Bi_(2)MoO_6-PPy nanosheets.This unique heterostructure can minimize the redox energy barrier on polysulfides due to the strong adsorption effect,high catalytic activity,and built-in electric field of Bi_(2)MoO_6-PPy nanosheets.The battery demonstrates good cycling stability when assembled with the functional separator modified by Bi_(2)MoO_6-PPy nanosheets,with an ultralow capacity decay of0.045%per cycle over 500 cycles at 2 C.Furthermore,even with a high sulfur loading(7.5 mg cm^(-2)),the battery retains an areal capacity of 6.3 mA h cm^(-2)at 0.2 C after 80 cycles.As a result,the suggested Mott-Schottky heterostructure-based Bi_(2)MoO_6-PPy nanosheets-modified separator(Bi_(2)MoO_6-PPy@PP separator)successfully suppresses the shuttle effect,providing an effective strategy for deploying efficient LSB.
作者
谷佳佩
冬晨旭
周铖
沈春丽
皮玉强
许絮
Jiapei Gu;Chenxu Dong;Cheng Zhou;Chunli Shen;Yuqiang Pi;Xu Xu(State Key Laboratory of Advanced Technology for Materials Synthesis and Processing,International School of Materials Science and Engineering,Wuhan University of Technology,Wuhan 430070,China;School of Chemistry and Materials Science,Hubei Engineering University,Xiaogan 432000,China)
基金
supported by Hainan Provincial Joint Project of Sanya Yazhou Bay Science and Technology City(520LH056)
the National Key Research and Development Program of China(2022YFB3803502)。
