Discussion Forum

Dear All

I have modelled two simple 2D models for fuel cell and electrolyzer. Perhaps I have modefied a 3D fuel cell model present on the comsol website and modified it to 2D. In the same way I have modelled the electrolyzer but only changing the gases to the inlet in the case of electrolyzer ( as in this case it will only be water on anode side ) and blocked the inlet of cathode. The electrolyzer model is giving me the correct polarization curve. I have made only those changes in the electrolyzer case(discussed above) nothing else. I have used the following interfaces i.e, Secondary current Distribution, Brinkman Equations (one for anode and one for cathode),transport of Conc. species(one for anode and one for cathode) ,

The thing that is not convincing me is the equations behind the program. As in the fuel cell case the valtage that we get is the subtraction of all the voltage losses from the Nernst Voltage i.e ( = Vnernst - (Vact+Vohmic+Vconc +...)) and in the electrolyzer case the voltage that we have to give is the addition of all the overpotentials i.e, (= Vnerst+ Vact+Vohmic+ Vconc+...). Using the same interfaces as those of the fuel cell and making no changes in the equations it is giving me the correct results for electrolyzer. I do not understand how it incorprated the addition of all losses in the electrolyzer case.

Your help is highly appreciated

Regards Rozanne