Dear Researchers :
Hello all, I hope someone could help me :)
How, o where, I can find the property: "Electrolyte conductivity" for the two materials I am using in Comsol Multiphysics, to model a Water Electrolyser.
The two materials in question are:
Platinum
Iridium Oxide (IrO2)
I am working with the Fuel Cells and Electrolyser modules of Comsol Multiphysics ver. 6.1
To tell the truth I don't even know what the "Electrolyte conductivity" for a solid material is.
I pulled out the domain conditions of "H2 Gas Diffusion Electrode" and "O2 Gas Difussion Electrode", to be able to taje into account my two catalysed electrodes, making a sandwich with the PEM Membrane.
But Comsol ask me to fill into the "Electrolyte conductivity" of each one
Or does ir is correct to use the same exact value as for the Electrical Conductivity of the material ??
I'm attaching an image
Thanks friends, I'll appreciate it !
Dear Franklin:
I guess you can use the electrolyte conductivity of Nafion, as it is the ionomer of an MEA in a water electrolyzer or a fuel cell.
Dear Erzhuo Zhao :
Thank you for your answer Zhao.
I see what you say, but
The "Electrolyte conductivity" I'm missing to run my model is not the one of the membrane (which effectively you implied as to be the "the electrolyte").
But the property missing, which Comsol is "requiring", is the EC of the two Electrocatalysts layers (namely the Platinum and the Iridium).
:(
Maybe in this case the Electrolyte Condcutivity of the material is exactly the same as the Electrical Conductivity of the material ?
Thanks, Regards !
Dear Franklin:
Nafion is not only a 'membrane' but also a 'binder' in an electrolyzer, that is, to prepare the catalyst ink, one will mix the Pt or Ir with Nafion solution in an alcohol system). In that case, Nafion will help to transport ions (such as protons) inside the catalyst layer, i.e., the Pt and Ir layers you mentioned. Hence, I guess you can use the electrolyte conductivity of Nafion as the EC of the two catalyst layers.
Tips: Electrolyte conductivity is totally different from the electrical conductivity for the same material. The electrolyte conductivity refers exclusively to the ion conduction. But the electrical conductivity contains electrolyte and electron conductivity, hence it has a larger scope. Unfortunately, the 'electrical conductivity' is abused in many fields, so people are misguided. I think the 'electrical conductivity' of Pt and Ir you mentioned refers only to the 'electron conductivity'.
For example, electrons can be transported in a Cu wire due to a potential difference, but ions cannot. So we can say Cu has high electron conductivity but low electrolyte conductivity. On the contrary, ions can be transported in an ionomer system, but electrons cannot, which means the ionomer has high electrolyte conductivity but low electron conductivity. However, these two materials both have high electrical conductivity.
Best regards! :D
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