⚡ Fuel Cell Thermodynamics
Analyze fuel cell performance using Nernst equation, Gibbs free energy, and polarization models. Compute open-circuit voltage, cell voltage under load, power density, and efficiency for PEM, SOFC, DMFC, and AFC types.
📝 Configuration
Key Equations:
ENernst = E°+ (ΔS/nF)(T−298) + (RT/nF)ln(PH₂·PO₂0.5)
Vact = (RT/αnF)·arcsinh(i/2i₀)
Vohm = i·Rarea
Vconc = −(RT/nF)·ln(1−i/ilim)
Vcell = ENernst − Vact − Vohm − Vconc
η = (ΔG/ΔH)·(Vcell/ENernst)
ENernst = E°+ (ΔS/nF)(T−298) + (RT/nF)ln(PH₂·PO₂0.5)
Vact = (RT/αnF)·arcsinh(i/2i₀)
Vohm = i·Rarea
Vconc = −(RT/nF)·ln(1−i/ilim)
Vcell = ENernst − Vact − Vohm − Vconc
η = (ΔG/ΔH)·(Vcell/ENernst)
📊 Results
Configure inputs and click Analyze to view results.
📘 Methodology
Nernst Equation
The open-circuit voltage depends on temperature and reactant partial pressures via the Nernst equation: E = E°(T) + (RT/nF)·ln(PH₂·PO₂0.5/PH₂O). Higher T reduces E for H₂ cells but improves kinetics.
Polarization Losses
Three loss mechanisms reduce cell voltage under load: Activation (sluggish electrode kinetics, dominant at low i), Ohmic (membrane/electrode resistance, linear in i), and Concentration (mass transport, dominant near ilim).
Cell Types
- PEM: 60–80°C, H₂ fuel, Pt catalyst
- SOFC: 700–1000°C, fuel flexible, ceramic electrolyte
- DMFC: 60–90°C, liquid methanol, portable
- AFC: 60–90°C, pure H₂/O₂, KOH electrolyte