An ultrathin and crack-free metal-organic framework film for effective polysulfide inhibition in lithium-sulfur batteries  

作　　者：Cheng Zhou Chenxu Dong Weixiao Wang Yu Tian Chunli Shen Kaijian Yan Liqiang Mai Xu Xu 

机构地区：[1]International School of Materials Science and Engineering,Wuhan University of Technology,Wuhan,Hubei,People's Republic of China [2]Department of Chemical Engineering,University of Massachusetts Amherst,Amherst,Massachusetts,USA

出　　处：《Interdisciplinary Materials》2024年第2期306-315,共10页交叉学科材料（英文）

基　　金：Fundamental Research Funds for the Central Universities,Grant/Award Numbers:WUT:2020Ⅲ023,2020Ⅲ050,2021Ⅲ009,2021ⅣA123;National Key Research and Development Program of China,Grant/Award Number:2022YFB3803502。

摘　　要：Due to their extensive microporous structure,metal-organic frameworks(MOFs)find widespread application in constructing modification layers,functioning as ion sieves.However,the modification layers prepared by existing methods feature gaps between MOFs that are noticeably larger than the inherent MOF pore dimensions.Polysulfides and lithium ions unavoidably permeate through these gaps,hindering the full exploitation of the structural advantages.Herein,an ultrathin(20 nm)and crack-free MOF film is formed on the separator by atomic layer deposition for the first time.Based on the separator,the mechanism of different MOF layers has been verified by phase field simulation and in situ Raman spectroscopy.The results accurately prove that the MOF particle layer can relieve the shuttle of polysulfides,but it does not have the effect of homogenizing lithium ions.Only the ultrathin and crack-free MOF film with proper pore size can act as the ion sieve for both polysulfides and lithium ions.As a result,under the test condition of 2mA cm^(-2)-2 mAh cm^(-2),the overpotential of the Li/Li symmetric battery is only 18 mV after 2500 h.The capacity retention rate of the lithium-sulfur battery is 95.6% after 500 cycles and 80% after 1000 cycles at 2 C.

关 键 词：crack-free film ion sieve lithium-sulfur battery metal-organic framework SEPARATOR 

分 类 号：TM912[电气工程—电力电子与电力传动]