(a) Change in In-situ X-ray scattering profile of EMI-TFSI in the
monolayer confinement of carbon nanopores of 0.7 nm under constant potentials of
0 V (black) and ± 2 V (+: red and -: blue). Here, we express application
of the electric potentials of 2 V for positive and negative electrodes as +2 V
and -2 V, respectively. (b, c, d) Experimental X-ray Reduced
Structure Functions (RSFs) of EMI-TFSI in the 0.7-nm pores under +2 V
(b), 0 V (c) and -2 V (d) with open
circles. The HRMC-simulated RSFs are plotted with black solid lines. The
simulated RSFs for the TFSI-TFSI correlation (red), EMI-EMI correlation (green)
and TFSI-EMI correlation (blue) are given as solid lines. (e)
Single plots of RSFs of TFSI-TFSI correlation in the 0.7-nm pores under +2 V
(red), 0 V (black) and -2 V (blue). (f, g, h) Snapshots of co-ion
pairs of anions of EMI-TFSI in the 0.7 nm-pore under +2 V (f), 0 V
(g) and -2 V (h). R is the ratio
of paired anion number to total anion number. TFSI anions are shown as red
ellipsoids. (i, j, k) Population in the first coordination shell
around a TFSI anion in the 0.7-nm pore under +2 V (i), 0 V
(j) and -2 V (k).