title: Electrochemical quartz crystal microbalance (EQCM) study of ion dynamics in nanoporous carbons.
abstract: Electrochemical quartz crystal microbalance (EQCM) and cyclic voltammetry (CV) measurements were used to characterize ion adsorption in carbide-derived carbon (CDC) with two different average pore sizes (1 and 0.65 nm), from neat and solvated 1-Ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (EMI-TFSI) electrolytes. From the electrode mass change in neat EMI-TFSI, it was shown that one net charge stored corresponds almost to one single ion at high polarization; in that case, no ion-pairing or charge screening by co-ions were observed. In 2 M EMI-TFSI in acetonitrile electrolyte, experimental solvation numbers were estimated for EMI(+) cation, showing a partial desolvation when cations were adsorbed in confined carbon pores. The extent of desolvation increased when decreasing the carbon pore size (from 1 down to 0.65 nm). The results also suggest that EMI(+) cation owns higher mobility than TFSI(-) anion in these electrolytes.
authors.affiliation: Université Paul Sabatier, CIRIMAT UMR CNRS 5085 , 118 route de Narbonne, 31062 Toulouse, France.
authors.forename: Wan-Yu
authors.initials: WY
authors.lastname: Tsai
authors.forename: Pierre-Louis
authors.initials: PL
authors.lastname: Taberna
authors.forename: Patrice
authors.initials: P
authors.lastname: Simon