  The increasing number of experimental observations on highly concentrated
electrolytes and ionic liquids show qualitative features that are distinct from
dilute or moderately concentrated electrolytes, such as self-assembly,
multiple-time relaxation, and under-screening, which all impact the emergence
of fluid/solid interfaces, and transport in these systems. Since these
phenomena are not captured by existing mean field models of electrolytes, there
is a paramount need for a continuum framework for highly concentrated
electrolytes and ionic liquids. In this work, we present a self-consistent
spatiotemporal framework for a ternary composition that comprises ions and
solvent employing free energy that consists of short and long range
interactions, together with a dissipation mechanism via Onsagers' relations. We
show that the model can describe multiple bulk and interfacial morphologies at
steady-state. Thus, the dynamic processes in the emergence of distinct
morphologies become equally as important as the interactions that are specified
in the equilibrium-free energy. The model equations not only provide insights
to transport mechanisms beyond the Stokes-Einstein-Smoluchowski relations but
also enables to qualitative recovery in the full range (three distinct regions)
of non-monotonic electrical screening length that has been recently observed in
experiments using organic solvent to dilute ionic liquids.
