Université Paul Sabatier, CIRIMAT UMR CNRS 5085 , 118 route de Narbonne, 31062 Toulouse, France.
J Am Chem Soc. 2014 Jun 18;136(24):8722-8. doi: 10.1021/ja503449w. Epub 2014 Jun 6.
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.
电化学石英晶体微天平（EQCM）和循环伏安法（CV）测量用于表征具有两种不同平均孔径（1nm 和 0.65nm）的碳化衍生碳（CDC）中的离子吸附，来自纯净和溶剂化的 1-乙基-3-甲基咪唑双（三氟甲烷磺酰基）亚胺（EMI-TFSI）电解质。从纯净 EMI-TFSI 中的电极质量变化可以看出，在高极化时，一个净电荷存储几乎对应于一个单一离子；在这种情况下，没有观察到离子对或同离子的电荷屏蔽。在乙腈电解质中的 2M EMI-TFSI 中，估算了 EMI(+)阳离子的实验溶剂化数，表明当阳离子在受限碳孔中吸附时，存在部分去溶剂化。当碳孔径从 1nm 减小到 0.65nm 时，去溶剂化的程度增加。结果还表明，在这些电解质中，EMI(+)阳离子比 TFSI(-)阴离子具有更高的迁移率。
