Effects of humidity and temperature on the electrochemical activities of H₂/O₂ PEMFCs using hybrid membrane electrolytes

Abstract

Electrochemical characteristics of single cell performances at various humidity conditions and constant temperatures of 40−100 °C using membrane electrode assemblies (MEAs) were studied. The MEAs consist of alternative proton-conducting hybrid membrane electrolyte and noble Pt/C catalyst for the H₂/O₂ proton exchange membrane fuel cells (PEMFCs). The function of humidity on the cell performances was investigated at larger current density values of 501 mA cm⁻² and constant cell temperatures of 80 and 90 °C and the relative humidity of 100 %. The power density value of 400 mW cm⁻² was obtained when the same MEA at similar operating conditions was used. The effects of temperature on the single cell performances were investigated at various temperature ranges of 40–100 °C and constant relative humidity of 50, 70, and 100 %. The maximum current density and power density values of about 600 mA cm⁻² and 160 mW cm⁻², respectively, were obtained at 90 °C with 100 % RH. The results were compared with the reported results of Nafion membrane and similar hybrid membranes operating at low temperatures for H₂/O₂ fuel cells. Finally, the results provided an alternative proton-conducting electrolyte as promising candidate for low/intermediate temperature operating H₂/O₂ fuel cells.