Understanding Lithium-ion Transport in Sulfolane- and Tetraglyme-Based Electrolytes Using Very Low-Frequency Impedance Spectroscopy

作     者：Janet SHo Oleg A.Borodin Michael SDing Lin Ma Marshall A.Schroeder Glenn R.Pastel Kang Xu Janet S.Ho;Oleg A.Borodin;Michael S.Ding;Lin Ma;Marshall A.Schroeder;Glenn R.Pastel;Kang Xu

作者机构：Energy Sciences DivisionSensors and Electron Devices DirectorateUS Army Research LaboratoryAdelphi MD 20783USA 

出 版 物：《Energy & Environmental Materials》 (能源与环境材料（英文）)

年 卷 期：2023年第6卷第1期

页      面：368-376页

核心收录：

学科分类：0808[工学-电气工程] 08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0703[理学-化学] 0702[理学-物理学] 

基　　金：This work was supported by US Department of Army and the Joint Center for Energy Storage Research(JCESR) an Energy Innovation Hub funded by Depart-ment of Energy Basic Energy Science under an Interagency Agreement No.IAA SN202095 

主　　题：anion-blocking conditions ion correlations low-frequency impedance spectroscopy transference number 

摘      要：With the increasing interest in highly concentrated electrolyte systems,correct determination of the cation transference number is ***-field gradient NMR technique,which measures self-diffusion coefficients,is often applied on liquid electrolytes because of the wide accessibility and simple sample ***,since the assumptions of this technique,that is,complete salt dissociation,all ions participating in motion,and all of them moving independently,no longer hold true in concentrated solutions,the transference numbers,thus obtained are often *** the present work,impedance spectroscopy at a frequency range of 1 MHz to 0.1 mHz was used to examine the concentration effect on lithium-ion transference number under anion-blocking conditions T abc Liþfor two electrolytes:lithium bis(fluorosulfonyl)imide(LiFSI)in sulfolane(SL)and lithium bis(trifluorosulfonyl)imide(LiTFSI)in tetraglyme(G4).The T abc Liþof the former was almost an order of magnitude higher than that of the *** also appeared to increase with increasing concentration while the latter followed an opposite *** faster Li^(+)transport in the SL system is attributed to the formation of a liquid structure consisting of extended chains/bridges of SL molecules and the anions,which facilitate a cation-hopping/ligand-exchanged-typed diffusion mechanism by partially decoupling the cations from the anions and solvent *** G4 system,in contrast,is dominated by the formation of long-lived,stable[Li(G4)]+solvation cages that results in a sluggish Li+*** difference between the two transport mechanisms is discussed via comparison of the bulk ionic conductivity,viscosity,ion self-diffusion coefficients,and the Onsager transport coefficients.