Enhanced proton conductivity and power density of HT-PEMFCs using tin pyrophosphate microparticles-dispersed polybenzimidazole composite electrolyte membranes

Abstract

Proton conductivity and acid retention property of PBI-based polymer electrolyte membrane is critical factor for high-temperature PEMFCs with high performance. The present study was undertaken in order to demonstrate the effect of SnP2O7 microparticles incorporation for the PBI-based membrane to the fuel cell performance. Besides, the correlation between dispersion property of additives and fuel cell performance was investigated, by taking the larger particle sizes of Sn-originated material into account. Highly dispersed SnP2O7 microparticles derived by the wet mechanochemical treatment has resulted in the novel PBI-based composite membrane with high-proton conductivity (4.17 mS cm−1 at 160 °C, anhydrous) and superior acid retention property. Consequently, the highest peak power density of 373 mW cm−2 at 160 °C under anhydrous conditions was achieved for the composite membrane with wet-mechanical milled SnP2O7, while the membrane without mechanochemical treatment showed lowest peak power density (168 mW cm−2) even inferior to the pure PBI membrane. Investigations into the PBI-based composite electrolyte membrane incorporated with highly dispersed SnP2O7 protonic conductive microparticles have yielded a performance enhancement of high-temperature PEMFCs.