Fundamentals and Applications of Fuel Cells with a Focus on Aviation

Abstract

Fuel cellsFuel cells are promising alternatives to fossil-fuel power conversion owing to their environmental friendliness, quiet operation, and high efficiency; after outlining the fundamentals (types, components, electrochemistry, operating principles), this work examines aviation applicationsAviation applications in depth specifically focusing on hydrogenHydrogen-powered aircraftAircraft, PEM and SOFCSolid Oxide Fuel Cells (SOFCs)-based propulsion systems, and hybrid architectures as detailed and situates them alongside other uses in defense, transportation, portable devices, and residential sectors to contextualize maturity. For aviation-relevant duty cycles, PEMFCsProton-exchange Membrane Fuel Cells (PEMFCs) provide the most favorable mix of specific power, rapid start-up, and low-temperature operability, making them strong candidates for APUs, hybrid architectures, and small-UAS propulsion; SOFCsSolid Oxide Fuel Cells (SOFCs) offer higher efficiency and fuel flexibility (H?/reformate) but slower dynamics due to thermal inertia, pointing to APU, range-extender, and hybrid roles where waste-heat recovery is valuable; AFC and PAFC face air-breathing constraints (CO2 sensitivity for AFC; lower specific power/response for PAFC) and thus appear limited to niche or closed-oxidant cases in the near term. We also show how fuel cell–battery hybrids mitigate transients and enable right-sizing of the stack, improving integration and indicative endurance versus battery-only baselines. A comparative table summarizes operating windows, reactant constraints, start-up/dynamics, and indicative endurance to guide architecture selection, and we close with an outlook on research priorities (higher specific power materials, CO2 tolerance, lightweight BoP) and the most credible near-term aviation pathways. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2026.