What Is the PEM Fuel Cell Polarization & Overpotential Calculator?
The polarization curve depicts fuel cell voltage output across varying electrical current densities.
How Does the PEM Fuel Cell Polarization & Overpotential Calculator Work?
At low current, activation losses dominate; at medium current, ohmic resistance dominates; at high current, gas starvation causes steep concentration drop.
PEM Fuel Cell Polarization & Overpotential Calculator Formula & Variables
The core mathematical equation utilized by this calculator is expressed as:
V_{\text{cell}} = V_{\text{ocv}} - b\log_{10}\left(\frac{i}{i_0}\right) - i \times \text{ASR} + \frac{R T}{n F}\ln\left(1 - \frac{i}{i_L}\right)
Sum of activation, ohmic, and concentration polarization losses subtracted from OCV.
How to Use the PEM Fuel Cell Polarization & Overpotential Calculator
- Input OCV, operating current density, Tafel slope, exchange current, ASR, and limiting current.
Step-by-Step Example Calculation
Automotive PEM Fuel Cell Cell
Input Values:
openCircuitVoltageVolts:1.2
currentDensityAcm2:0.8
tafelSlopeVoltsPerDecade:0.07
exchangeCurrentDensityAcm2:0.0001
areaSpecificResistanceOhmCm2:0.15
limitingCurrentDensityAcm2:2
Worked Steps: Predicts 0.781 V operating cell voltage and 0.625 W/cm² power density at 0.8 A/cm².
Understanding Your Result
Displays operating cell terminal voltage, net power density (W/cm²), and loss breakdowns in millivolts.
Factors That Affect the Result
- Thinner membranes reduce ohmic ASR; advanced platinum catalysts reduce activation losses.
When Should You Use This Calculator?
- Hydrogen vehicle powertrain fuel cell stack sizing and performance benchmarking.
Assumptions & Limitations
- Applies to steady-state operation at fixed temperature, humidity, and gas stoichiometry.
Frequently Asked Questions
Calculation Accuracy & Reference Note
Standard polarization model taught across electrochemical engineering curricula.