Electrochemical devices with optimized gas tightness for the diffusivity measurement in fuel cells

The technique allowing for direct gas diffusivity measurement in fuel cells has been advanced rapidly in recent years. Such development has largely improved the accuracy in the evaluation of fuel cell limiting current density (LCD) and overall concentration polarization (CP). However, electrolyte discs were employed in all the previous gas diffusivity electrochemical devices, which inevitably induced gas leak in the gas diffusivity measurement. In this report, quantitative analysis is performed to evaluate the correlation between gas leak and the important fuel cell parameters including electrode diffusivity, LCD and CP. To avoid gas leak, electrochemical devices without any electrolyte discs is then proposed. Our quantitative study and the proposed devices facilitate the accurate analysis on the electrochemical performance of a fuel cell system and the development of highly-efficient fuel cells.