What Is the Fuel Cell Reversible Nernst Potential Calculator?
The Nernst potential is the maximum thermodynamic open-circuit voltage produced by a fuel cell before current is drawn.
How Does the Fuel Cell Reversible Nernst Potential Calculator Work?
Gibbs free energy change determines baseline E0, while partial pressures shift chemical potential via the logarithmic Nernst term.
Fuel Cell Reversible Nernst Potential Calculator Formula & Variables
The core mathematical equation utilized by this calculator is expressed as:
E = E_0(T) + \frac{R T}{2 F} \ln\left( P_{H_2} P_{O_2}^{1/2} \right), \quad E_0(T) \approx 1.229 - 0.00085(T - 298.15)
Temperature-adjusted Nernst equation for hydrogen-oxygen electrochemical reactions.
How to Use the Fuel Cell Reversible Nernst Potential Calculator
- Input cell temperature, hydrogen and oxygen partial pressures, and standard baseline potential.
Step-by-Step Example Calculation
Pressurized PEMFC Stack
Input Values:
temperatureCelsius:60
hydrogenPartialPressureAtm:2
oxygenPartialPressureAtm:1
standardReversiblePotentialVolts:1.229
Worked Steps: Predicts reversible open-circuit voltage of 1.210 V at 60 °C and 2 atm H2 pressure.
Understanding Your Result
Outputs open circuit voltage, temperature-corrected standard potential, and pressure enhancement.
Factors That Affect the Result
- Higher operating temperatures lower reversible potential, while higher reactant pressures increase it.
When Should You Use This Calculator?
- PEMFC and SOFC stack modeling and electrochemical efficiency benchmarking.
Assumptions & Limitations
- Assumes ideal gas behavior and product liquid water activity equal to 1.
Frequently Asked Questions
Calculation Accuracy & Reference Note
Fundamental thermodynamic equation established by Walther Nernst.