Functional-selected LiF-intercalated-graphene enabling ultra-stable lithium sulfur battery

• 作者: Haoliang Lu Na Xu Xuyan Ni Jinqiu Zhou Jie Liu Zhenkang Wang Tao Qian Chenglin Yan
• 来源期刊: 能源化学
• 年，卷（期）: 2021,（7）
• 页码范围: 78-84
• 页数: 7页
• 语种: 英文

摘要

Using a functionally selective solid electrolyte interphase (SEI) as an anodic protection layer can effectively avoid the subsequent settlement of uneven lithium electrodeposits for lithium sulfur (Li-S) batteries.To address the issues of single functional,mechanical crushing and peeling of the conventional rigid LiF SEI,a unique functional-selected rigid-flexible-coupled LiF-intercalated-graphene (LiF-GN) SEI as anodic protection is constructed,which is verified by in-operando X-ray photoelectron spectroscopy (XPS) spectra.Owing to the synergistic effect of the LiF and graphene layer,this intercalated functionalselected SEI architecture exhibits a dramatic elastic modulus (rigid-flexible coupling with a shallow Young's modulus (～430 MPa) and a tremendous Young's modulus of～20 GPa),high mechanical strength,and can be repulsive to polysulfides,accompanied unprecedented trafficability of Li ions.Consequently,the forceful exclusion of polysulfides from the LiF-GN SEI,as confirmed by means of in-situ UV/vis analysis,Li2S nucleation tests,and visual permeation experiments,is of profound significance for the effective protection of Li anodes and enables Li-S batteries to achieve remarkable electrochemical performance (ultralow capacity decay rate of 0.022％ during 300 cycles at 1 C and high discharge capacity of 1092 mAh/g at 0.5 C).