On the Influence of Surface Topography on the Electric Double Layer Structure and Differential Capacitance of Graphite/Ionic Liquid Interfaces

• DOI: 10.1021/jz200879a
• Publication Date: 2011-08-16T16:44:53Z
• Authors: Jenel Vatamanu; Liulei Cao; Oleg Borodin; Dmitry Bedrov; Grant D. Smith
• Keywords: Differential capacitance

Molecular simulations reveal that the shape of differential capacitance (DC) versus electrode potential can change qualitatively with structure surface. Whereas atomically flat basal plane graphite in contact a room-temperature ionic liquid generates camel-shaped DC, corrugated prismatic face same electrolyte exhibits bell-shaped behavior and much larger DCs at low double-layer potentials. The observed DC was correlated structural changes occurring double layer as function applied potential. Therefore, surface topography clearly influences behavior, suggesting attention should be paid to characterization studies ensure reproducibility unambiguous interpretation experimental results. Furthermore, our results suggest controlling roughness/structure could route improving energy densities electric capacitors.