Enhancement of efficiency and power output of hydrogen fuelled proton exchange membrane (PEM) fuel cell using oxygen enriched air

This paper deals with the effects of the oxygen-enriched air (up to 50% oxygen by mass) along with other operating parameters (hydrogen flow rate, temperature, and relative humidity) on the performance of hydrogen-fuelled proton exchange membrane (PEM) fuel cell. The active area of a fuel cell considered was 50 cm2 with three cells in series connections. The air was supplied with O2 enriched from 23% to 50% at the cathode. The voltage obtained with the respective enriched air was 2.52 and 2.80 V respectively. The optimum oxygen enrichment was found as 45%. The stack temperature plays a significant role on performance improvement and the optimum temperature was found as 50 degrees C. The voltage efficiency and power output were improved by 9% and 33% with 45% oxygenenriched air. Electrochemical impedance spectroscopy was used to analyze the impedance behavior of the fuel cell with the variable current demand. The bode plot indicates current dominates voltage at low oxygen-enriched air (25%) and vice-versa at highenriched air. The inductive effect was dominating at the low frequency and overtaken by the capacitive effects at the higher frequency. These results would be useful to develop a dedicated fuel cell with the oxygen-enriched air. (c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

This paper investigates the effects of oxygen-enriched air, along with other operating parameters, on the performance of a hydrogen-fuelled proton exchange membrane (PEM) fuel cell. The results show that 45% oxygen enrichment is optimal, and the stack temperature plays a significant role in performance improvement. The voltage efficiency and power output are improved with 45% oxygen-enriched air. Electrochemical impedance spectroscopy reveals the impedance behavior of the fuel cell under variable current demand.