Cell performance and polarization analysis on different operating conditions in anion exchange membrane-unitized regenerative fuel cells (AEM-URFCs)

Several electrode parameters and operating conditions were investigated on the cell performance of anion exchange membrane-unitized regenerative fuel cell (AEM-URFC). The AEM-URFC's performance increased with increasing the ionomer and catalyst contents on the electrode up to an optimum amount and then decreased due to the blockage of mesopores on the catalyst layers. The AEM-URFC with optimal ionomer and catalyst loaded showed the maximum current (255.0 mA/cm(2)) and power (127.5 mW/cm(2)) density at 0.50 V for fuel cell mode at 60 & DEG;C. Also, three different kinds of commercial AEMs were tested in URFC. The catalyst for the bifunctional oxygen electrode had a pronounced influence on the cell performance of AEM-URFC. Ir black showed the highest WE performance than other precious catalysts (Pt/C, PtRu black, and IrO2), but lower performance in FC mode than Pt/C and PtRu catalysts. The optimized AEM-URFC had 48.30% round trip efficiency, which is comparable or superior to the results reported in the literature.