Topological defects in electric double layers of ionic liquids at carbon interfaces

Journal Article · Sun Jun 07 00:00:00 EDT 2015 · Nano Energy

DOI:https://doi.org/10.1016/j.nanoen.2015.05.037· OSTI ID:1214494

Black, Jennifer M. ^[1]; Okatan, Mahmut Baris ^[1]; Feng, Guang ^[2]; Cummings, Peter T. ^[3]; Kalinin, Sergei V. ^[1]; Balke, Nina ^[1]

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1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
2. Huazhong Univ. of Science and Technology, Wuhan (China)
3. Vanderbilt Univ., Nashville, TN (United States)

The structure and properties of the electrical double layer in ionic liquids is of interest in a wide range of areas including energy storage, catalysis, lubrication, and many more. Theories describing the electrical double layer for ionic liquids have been proposed, however a full molecular level description of the double layer is lacking. To date, studies have been predominantly focused on ion distributions normal to the surface, however the 3D nature of the electrical double layer in ionic liquids requires a full picture of the double layer structure not only normal to the surface, but also in plane. Here we utilize 3D force mapping to probe the in plane structure of an ionic liquid at a graphite interface and report the direct observation of the structure and properties of topological defects. The observation of ion layering at structural defects such as step-edges, reinforced by molecular dynamics simulations, defines the spatial resolution of the method. Observation of defects allows for the establishment of the universality of ionic liquid behavior vs. separation from the carbon surface and to map internal defect structure. In conclusion, these studies offer a universal pathway for probing the internal structure of topological defects in soft condensed matter on the nanometer level in three dimensions.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• Grant/Contract Number: AC05-00OR22725; AC02-05CH11231
• OSTI ID: 1214494
• Alternate ID(s): OSTI ID: 1251832
• Journal Information: Nano Energy, Vol. 15; ISSN 2211-2855
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

97 MATHEMATICS AND COMPUTING
ionic liquid
carbon
electric double layer
defect
atomic force microscopy