Simulation-Based Analysis of Thermal and Electrical Degradation in High-Temperature PEM Fuel Cells for Hydrogen Aircraft Applications

The integration of high-temperature proton exchange membrane fuel cells into hydrogen-powered regional aircraft is evaluated in the scope of this paper, focusing on a concept aircraft with ten propulsion units, each containing a hybrid fuel cell system. High-temperature PEM fuel cells, operating at temperatures between 140°C and 200°C, offer potential advantages in cooling performance compared to low-temperature PEM fuel cells, which operate between 60°C and 80°C and require large and complex cooling systems due to their limited temperature difference with the environment. As part of early system design, an empirical degradation model for high temperature PEM fuel cells is developed and applied to assess degradation effects, cooling performance, and hybridization requirements. Key findings include the identification of temperature as a critical factor in high-temperature PEM fuel cells degradation, the lifespan increase due to hybridization and oversizing of the fuel cell system, and the determination that air cooling systems are infeasible at operating temperatures below 330°C. Despite their anticipated advantages, high-temperature PEM fuel cells have a shorter operational lifespan of approximately 3610 h in the presented use case, compared to about 8610 h for low-temperature PEM fuel cells, primarily due to their currently lower level of technological maturity.