Fabrication and Characterisation of Sulfonated Polysulfone Membrane with Different Thicknesses for Proton Exchange Membrane Fuel Cell

Abstract

Membranes play a critical role in the performance of proton exchange membrane fuel cells. Membrane thicknesses have posi-tive and negative effects on the characteristics of proton exchange membranes. In this study, sulfonated polysulfone (SPSf) pol-ymer-based membranes with thicknesses of 50 μm, 100 μm, and 150 μm were fabricated, and their characteristic properties were investigated. Water uptake capacity, swelling ratio, proton conductivity, contact angle, chemical stability, and mechanical strength tests were carried out on the membranes. Maximum water uptake capacity and swelling ratio were 45.81% and 13.1% for 100 μm SPSf membrane, respectively. The results of contact angle analysis proved that all synthesized membranes were hydrophilic. Proton conductivity values were measured at different temperatures and solution environments. Significant decreases in resistance values and increases in proton conductivity were observed with decreasing membrane thickness. The increase in temperature and acid in the measurement conditions caused an increase in the proton conductivity value. The highest proton conductivity value was obtained as 0.1971 S/cm in 65 °C and 1 mM hydrochloric acid (HCl) aqueous solution environment in 50 μm SPSf mem-brane. It was determined that the chemical stability and mechanical strength decreased with the decrease in membrane thickness but remained within the appropriate limits.

Keywords

• fuel cell
• membrane
• proton exchange membrane
• sulfonated polysulfone
• thickness