Charge storage in two-dimensional systems

The storage of ions in a narrow slit between two electrodes has been investigated within a mean-field theory and by Monte Carlo simulations within a grand-canonical ensemble. The former explains basic features of the interfacial capacitance, the latter gives structural details and complements previous work on this topic. In particular we have observed large fluctuations and transient structures in the transition region between a gas-like and a glass-like structure, which is reminiscent of a phase transition. In the case of a 1-2 electrolyte at high positive potentials the ions can enter in the form of pairs, thereby reducing Coulomb repulsion.