Diffuse Double Layer with Charge Transfer
Application ID: 13525
In the diffuse double layer and within the first few nanometers of an electrode surface, the assumption of electroneutrality is not valid due to charge separation. Typically, the diffuse double layer may be of interest when modeling very thin layers of electrolyte including those in electrochemical capacitors and microelectrodes. This example shows how to couple the Nernst-Planck equations to Poisson’s equation, in order to consider this deviation from electroneutrality. A Stern layer with constant capacity is used to derive surface charge boundary conditions for Poisson’s equation. This 1D model reproduces the results published in literature.
This model example illustrates applications of this type that would nominally be built using the following products:
however, additional products may be required to completely define and model it. Furthermore, this example may also be defined and modeled using components from the following product combinations:
- COMSOL Multiphysics® and
- either the Battery Design Module, Corrosion Module, Electrochemistry Module, Electrodeposition Module, or Fuel Cell & Electrolyzer Module
The combination of COMSOL® products required to model your application depends on several factors and may include boundary conditions, material properties, physics interfaces, and part libraries. Particular functionality may be common to several products. To determine the right combination of products for your modeling needs, review the Specification Chart and make use of a free evaluation license. The COMSOL Sales and Support teams are available for answering any questions you may have regarding this.