Effect of hydrogen temperature and current load on the performance of proton exchange membrane fuel cell under start-stop operation

Abstract

Proton Exchange Membrane Fuel Cell (PEMFC) is one of fuel cell type that suitable for vehicular application because it has low operation pressure and temperature, stable, relatively small, and highly mobile. The major concern of PEMFC as vehicular power is its resistance toward start-stop cycle and constant load. PEMFC on vehicular application require fuel processor to produce hydrogen as fuel source. Output temperature of hydrogen from fuel processor is about 80°C, which is high enough for PEMFC. The temperature is allegedly affecting the performance of PEMFC. This research is focused on studying the effect of hydrogen feed temperature on the performance of PEMFC. Fuel cell is operated in the start-stop cycle and constant load to simulate the conditions in vehicular application. PEMFC stack has been operated with 10 start-stop cycles under constant load of 0.05 and 0.1 A/cm2 at temperatures 25, 40, 60, and 80°C. The electrochemical characterizations were carried out using chronopotentiometry and potentiodynamic polarization, while post experimental physical observations were carried out by using XRD and SEM. The experimental results show that under low constant load (0.05 A/cm2), the increase of hydrogen temperature has raised stack performance when operated with start-stop cycles, but lowered the stack performance when operated without start-stop cycle. Under high constant load (0.1 A/cm2), higher hydrogen temperature increased the stack performance, either operated with or without start-stop cycle. Post experimental XRD and SEM analysis show that the decrease of PEMFC performance is caused by platinum catalyst particles growth and MEA thickness alteration.