Ionic insertion and exchange and ionic diffusion inside the MXene (Ti₃C₂(OH)₂) slit nanopore during galvanostatic cycling process is simulated.

Charge storage takes place by a fast counter-ion insertion and counter-ion/co-ion exchange during charge/discharge process.

Spatial distribution of ions and orientation of cation dipoles vary cyclically to screen the external electric potential.

A complement to the restriction of the in situ measurements in understanding the underlying charge storage mechanism.