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Title: In Situ Probing of Ion Ordering at an Electrified Ionic Liquid/Au Interface

Charge transport at the interface of electrodes and ionic liquids is critical for the use of the latter as electrolytes. In this study, a room-temperature ionic liquid, 1-ethyl-2,3-dimethylimidazolium bis(trifluoromethanesulfonyl)imide (EMMIM TFSI), is investigated in situ under applied bias voltage with a novel method using low-energy electron and photoemission electron microscopy. Changes in photoelectron yield as a function of bias applied to electrodes provide a direct measure of the dynamics of ion reconfiguration and electrostatic responses of the EMMIM TFSI. Finally, long-range and correlated ionic reconfigurations that occur near the electrodes are found to be a function of temperature and thickness, which, in turn, relate to ionic mobility and different configurations for out-of-plane ordering near the electrode interfaces, with a critical transition in ion mobility for films thicker than three monolayers.
 [1] ;  [1] ;  [2] ;  [3] ; ORCiD logo [1]
  1. Brookhaven National Lab. (BNL), Upton, NY (United States). Center for Functional Nanomaterials
  2. Brookhaven National Lab. (BNL), Upton, NY (United States). Chemistry Division
  3. Brookhaven National Lab. (BNL), Upton, NY (United States). Sustainable Energy Technologies Department
Publication Date:
Report Number(s):
Journal ID: ISSN 0935-9648; R&D Project: 16083/16083; KC0403020
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Advanced Materials
Additional Journal Information:
Journal Volume: 29; Journal Issue: 27; Journal ID: ISSN 0935-9648
Research Org:
Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
36 MATERIALS SCIENCE; 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; electric double layers; ionic liquids; photoemission electron microscopy
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1401792