Proton Exchange Membrane Fuel Cells for Aircraft Applications: A Comprehensive Review of Key Challenges and Development Trends

Hydrogen energy is a pivotal alternative to lithium-ion batteries for low-altitude aircraft, offering a pathway to sustainable aviation with its zero emissions and high energy density. Nevertheless, its broader application is hindered by challenges in storage, safety, and performance under extreme conditions such as low pressure and low temperature at high altitudes. This paper systematically evaluates various hydrogen power technologies—including water-cooled and air-cooled proton exchange membrane fuel cells (PEMFCs) as well as hydrogen turbines—highlighting their respective advantages, limitations, and suitability for different aircraft types. Among these, water-cooled PEMFCs are identified as the most viable option for manned low-altitude aircraft due to their balanced performance in power density and startup capability. In contrast, air-cooled PEMFCs demonstrate distinct cost-effectiveness for lightweight drones, while hydrogen turbines show promise for long-range regional transport. Furthermore, we analyze current progress in integrating PEMFCs into aircraft platforms and discuss persistent challenges in system compatibility and environmental adaptation. Finally, potential future development directions for PEMFC applications in low-altitude aviation are outlined.