Electrochemical Quartz Crystal Microbalance (EQCM) Study of Ion Dynamics in Nanoporous Carbons

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• 作者：Wan-Yu Tsai ; Pierre-Louis Taberna ; Patrice Simon
• 刊名：Journal of the American Chemical Society
• 出版年：2014
• 出版时间：June 18, 2014
• 年：2014
• 卷：136
• 期：24
• 页码：8722-8728
• 全文大小：371K
• 年卷期：v.136,no.24(June 18, 2014)
• ISSN：1520-5126

文摘

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^{鈥?/sup> anion in these electrolytes.}