Figure 30.

Four charging regimes from MD simulations. (a) At short times, the accumulated charge (Q) grows as a square root of time. (b) At later times, Q saturates exponentially and enters a superslow regime, during which it saturates exponentially with a larger decay time constant. The superslow regime is related to pore overfilling (the inset). Reproduced with permission from ref (113). Copyright 2014 Nature Publishing Group. (c) In addition to the square-root and exponential regimes, at very short times, there is a linear regime during which the charge grows linearly with time (see the inset). This regime is due to ion migration caused by the applied cell voltage acting on the ions outside of the pore. (d) Snapshots from MD simulations typical for various charging regimes. During the short-time linear regime, the neutral ionic liquids is “compressed” inside the pore by the adsorbed counterions. The charging proceed by melting an “interface” between a dense, neutral and a dilute, charged transient ionic liquid phases. Adapted with permission from ref (125). Copyright 2018 American Chemical Society.