Performance and thermal optimization of different length-width ratio for air-cooled open-cathode fuel cell

Open-cathode polymer electrolyte fuel cells with compact design have attracted increasing attention in the field of portable energy equipment. This study explores the impacts of different length-width ratios (R) of the cell with the same active area (50 cm) on cell performance based on various measurements of polarization curves, air velocity profile, and temperature distribution. Results suggest that R has a significant impact on cell performance. Remarkably, a performance improvement of 7% is achieved with the increase of R (4.14–22.40) due to the enhancement of heat and mass transfer ability. The maximum temperature difference at the cathode outlet surface is less than 2 °C when R is 22.40. It is also indicated that the optimum cathode outlet surface temperature is about 48～52 °C. Under the condition of ensuring the structural strength and performance of the cell simultaneously, the appropriate range of R is confirmed as 10–20. The results provide basic data and technical support for the system design and application of open-cathode fuel cells.