A lattice model for the electric double layer

The most difficult part of the metal-electrolyte interface to properly describe is the layer of electrolyte adjacent to the metal surface. A model is presented to treat the simple case where this layer consists entirely of water molecules. Approximations that include more than simple mean-field effects are used to treat the interactions between the molecules. It is shown that the effects of local order produce significant qualitative changes in the predicted inner layer differential capacitance curves;An inner layer thickness variation proportional to the net orientation of the molecules in the layer is proposed. With this thickness dependence it is possible to obtain good agreement between the predictions of the model and the experimentally inferred inner layer capacitance curves of the water inner layer and mercury electrodes