The Membrane node specifies a domain with only an Electrolyte Phase node being active.

The electrolyte conductivity of the membrane is defined on the Electrolyte Phase node.

The Crossover sections for H2, O2 and N2, available if the corresponding crossover species has been selected in the Membrane Transport section on the interface top node, can be used to specify the Permeation coefficient and the Henry’s law coefficient of the corresponding species. The Heat of reactions, arising due to the parasitic reactions of H2 and O2 species, is available if H2 or O2 has been selected as crossover species. The Thermoneutral voltage is calculated automatically when the Built in option is used.

See also Membrane Crossover Theory.

This section is visible if Electroosmotic water drag has been selected in the Membrane Transport section on the interface top node. The Water transport model can be selected as either Vapor equilibrated (default for fuel cells) or Liquid equilibrated (default for electrolyzers). The Electroosmotic coefficient, the Water transport coefficient, and the Standard condition gas pressure are specified in this section. The Heat of water absorption is available if Electroosmotic water drag has been selected.

See also Electroosmotic Water Drag Theory.

This section is visible if Electroosmotic water drag has not been selected in the Membrane Transport section on the interface top node. The water activity specified in this section is used by the Electrolyte Phase node when using an electrolyte material that requires Water activity (relative humidity) as model input.