Air-cooled compact hydrogen fuel cell stack (210 W): design and development

Hydrogen fuel cells are a key technology for sustainable energy systems. However, most existing systems are primarily designed for high-power applications, while compact portable fuel cells remain underexplored. In this study, an air-cooled compact hydrogen fuel cell stack is designed and developed to meet the technical demands of low-power applications (210 W). First, a five-serpentine channel is proposed, achieving a high-velocity area-weighted uniformity index of 0.8, which is significantly higher than that of conventional designs, thereby improving hydrogen distribution uniformity and electrochemical performance. Second, single-cell experiments using membrane electrode assemblies with gas diffusion layers (GDLs) of three thicknesses show that the MEA with a 280-μm GDL delivers stable power outputs ranging from 9.6 to 24.8 W in the ohmic polarization region. Third, the influence of fan duty cycle on stack performance is systematically investigated under various current densities. The results show that, at 20°C, the optimal fan duty cycles corresponding to current densities of 100, 200, 300, 400, 500, 600, and 700 mA·cm−2 are 25%, 45%, 56%, 66%, 78%, 87%, and 100%, respectively. Based on these optimizations, the developed nine-cell stack achieves a rated output power of 210 W at 500 mA·cm−2 and a maximum output power of 257 W at 700 mA·cm−2, with a peak power density of 0.30 W·cm−2. This work provides a practical technical pathway for the design and optimization of low-power hydrogen fuel cells and offers valuable insights for the development of portable hydrogen-powered devices.