Use the Electrolyte node to define an electrolyte domain that only conducts current in the ion conducting phase.

Note that electrolyte in this case does not refer to the pore electrolyte in porous electrodes (which should be defined by a Porous Electrode node instead).

The Electrolyte conductivity, σl (SI unit: S/m), parameter will define how the current in the domain depends on the gradient of the potential.