Electrolyte
Use the Electrolyte node to define an electrolyte domain that only conducts current in the ion conducting phase. The combined charge and mass transfer in the electrolyte is defined by the node.
What settings are available in this node depends on the Electrolyte Charge Conservation setting, available on the top node. The Electrolyte conductivity (SI unit: S/n) setting is only available for the Supporting Electrolyte option. Diffusivity and mobility settings for H+ and OH- are only available for the Electroneutrality, water-based option.
The Convection section is available when the Convection check box is selected on the interface top node. The Velocity field u (SI unit: m/s) of the solvent is specified as a feature input. Select the source of velocity field from the velocity field list.
By default the Mobility (SI unit: s·mol/kg) for each species is set to be calculated based on the Diffusion coefficients (SI unit: m2/s) and the temperature using the Nernst-Einstein relation.
The mobility setting will only have an impact on the transport by migration of charged species, as defined by the Charge number zc (dimensionless, specify negative charges using a minus sign). For the Electroneutrality charge conservation model you need at least one positively and one negatively charged species (ion) in the electrolyte.
Specify the temperature (if you are using mobilities based on the Nernst-Einstein relation) in the Model Inputs section.
The Water Self-ionization section is available for the Electroneutrality, water-based option. The section allows the water self-ionization constant to be set. Using the Built in option, the constant will be set to account for temperature, giving the pH of the simulation the correct temperature dependence.
Note that the electrolyte in this case does not refer to the pore electrolyte in porous electrodes (which should be defined by a Porous Electrode node instead). For porous separators, use the Separator instead.