Development of a solid polymer electrolyte membrane based on sulfonated poly(ether ether) ketone and polysulfone for fuel cell applications

Polymer electrolyte membranes made of sulfonated poly(ether ether) ketone (SPEEK) and polysulfone (PSf) (2-10 wt %) were prepared by a solution casting method. The characteristic properties of the SPEEK/PSf polymer blend membranes were investigated using thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and the AC impedance method. The SPEEK/PSf blend membranes showed good thermal and mechanical properties and appreciable ionic conductivity. It was revealed that the addition of PSf into the SPEEK matrix could markedly improve the electrochemical properties of the resulting membranes, which can be accomplished by a simple blend method. As a result, the SPEEK/PSf blends appear to be good candidates for the proton exchange membrane fuel cell (PEMFC) and direct methanol fuel cell (DMFC) applications. These blend membranes, having various amounts of PSf (2-10 wt %), were investigated in PEMFC and DMFC. The power densities were about 400 and 50 mW/cm(2) for PEMFC and DMFC, respectively. This makes PSf-based DMFC and PEMFC suitable for application in portable devices and transportation, respectively.