  Spurred by the increasing needs in electrochemical energy storage devices,
the electrode/electrolyte interface has received a lot of interest in recent
years. Molecular dynamics simulations play a proeminent role in this field
since they provide a microscopic picture of the mechanisms involved. The
current state-of-the-art consists in treating the electrode as a perfect
conductor, precluding the possibility to analyze the effect of its metallicity
on the interfacial properties. Here we show that the Thomas-Fermi model
provides a very convenient framework to account for the screening of the
electric field at the interface and differenciating good metals such as gold
from imperfect conductors such as graphite. All the interfacial properties are
modified by screening within the metal: the capacitance decreases significantly
and both the structure and dynamics of the adsorbed electrolyte are affected.
The proposed model opens the door for quantitative predictions of the
capacitive properties of materials for energy storage.
