I have an OCV of 0.7 but i have less than 1mW/cm2 in my I-V polarization curve.
What type of fuel cell is this? For example, 0.7 V is not a high OCV for a H2/air PEMFC. OCV values are not typically a good indicator of cell performance. The low power density under load could be caused by any number of problems such as slow kinetics, high ohmic losses, low mass transfer, etc. Without much more specific information it is very difficult to give any indication of what the problem could be.
I use commercial Ni/C and Pt/C for anode and cathode respectively. i use carbon paper as GDL and anion exchange membrane....my fuel is adblue and electron acceptor is humidified air.
Comparing to this study, it's not wildly out of line - https://www.nature.com/articles/srep05863
1) Could also be that activation overpotential losses are relatively high for Ni/C vs. NiCo/C (especially if you're running lower than 60 °C); did you activate the nickel catalyst beforehand? This is something to ask the supplier & maybe they have an SOP - nickel can be tricky as a catalyst, since hitting steady-state operation can take an incredibly long time. Also, you can investigate whether it's activation losses through temperature dependency (are you running at 60 °C?) since the effect of temperature on catalytic activity is of disproportionally large effect vs. crossover and (to a lesser degree) membrane conductivity.
2) You may be getting lower crossover from a comparatively thick but highly resistive membrane vs. the study - this raises OCV but increases losses in what Ohmic region you have. What AEMs are you using and how thick are they?
3) I can't imagine ORR is limiting, but using backpressure and/or O2 is worth a shot again to determine dependency or not.
Thank you both Mrs. Diaz and Mr. Britton .
how can i activate the nickel catalyst ? I taste at room temperature.i use a membrane thickness of 130 um. i plan to use humidified oxygen instead of humidified air. how can it affect the DO(dissolved oxygen) for my ORR?
can i expect a better performance if use carbon cloth instead of carbon paper as cathode GDL?
Dear Robel Mehari,
measuring (a set of) EIS, applying a VDC near the DC polarization of your interest (VDC near 0.7V), will help you to illuminate, farther, your investigation(s).
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