Highly Conductive Porous Electrode
Use this node to define a porous electrode that has electrolyte-filled pores and a highly conductive electron phase with potential gradients considered to be negligible.
In the Porous Matrix Properties, the porosity and tortuosity (available depending on transport correction setting) can be adjusted from the default values that for both properties are 1.
In the Effective Transport Parameter Correction section, the mass transport correction in the porous media is defined. The default correction is Bruggeman, which multiplies the diffusivity and mobility values by the porosity to the power of 1.5. Other available corrections are Tortuosity, User defined, or No correction.
Use the Harmonic Perturbation section in conjunction with AC Impedance study types to control the perturbation amplitude in the frequency domain. The perturbation parameter is either Electric potential or Total current based on the Electrode phase potential condition selected in the next section.
Electrode phase potential Condition
This section specifies the potential in the electrode phase of the electrolyte-electrode interface. The electrode potential is used (via the overpotential) by the Porous Electrode Reaction subnodes.
Use the Electric potential option (default) to set the value of the potential explicitly with respect to ground. The other option, Total current, adds an extra global degree of freedom for the potential in the electrode phase, set to comply with the chosen condition. When using the Total current option in 1D or 2D, the boundary area is based either on the Cross-Sectional Area (1D), or the Out-of-Plane Thickness (2D) properties, set on the physics interface top node.
Dissolving–Depositing Species
Use the settings of this section to define species that participate in dissolution–deposition electrode reactions, for instance metal deposition/dissolution or oxide formation.
Use the Add () and Delete () buttons as needed in the table to control the number of species. The name of each dissolving–depositing Species can be edited in the first column of the table.
The Subtract volume change from electrolyte volume fraction is by default selected and calculates an electrolyte volume fraction that depends on the concentration of deposed species.
The Stoichiometric Coefficients section in Porous Electrode Reaction and Reaction subnodes is used to set the stoichiometric coefficients for dissolving-depositing species.
Adsorbing–Desorbing Species
Use the settings of this section to define species that can adsorb or desorb on the electrode surface.
The Density of sites parameter will be used to set up the local surface mass balance equations for the fractional surface coverages.
Use the Add () and Delete () buttons as needed in the table to control the number of species. The name of each adsorbing–desorbing Species can be edited in the first column of the table.
The Stoichiometric Coefficients section in the Porous Electrode Reaction and Reaction subnodes is used to set the stoichiometric coefficients for adsorbing–desorbing species reaction.