High-performance SPEEK/SWCNT/fly ash polymer electrolyte nanocomposite membranes for fuel cell applications

Sulfonated poly (ether ether ketone) (SPEEK)-based polymer nanocomposite membranes containing single-walled carbon nanotubes (SWCNTs) and fly ash as inorganic fillers have been prepared using a solution casting technique. The degree of sulfonation of poly (ether ether ketone) was determined by proton nuclear magnetic resonance spectroscopy analysis and was found to be 64%. Scanning electron microscopy and X-ray diffraction analyses confirmed the incorporation of nanofillers into the polymer matrix. The physicochemical properties of the prepared membranes were studied to evaluate their suitability for fuel cell applications. The SP-CNT-FA-8 membrane exhibited the highest proton conductivity of 0.027 S cm(-1) at 30 degrees C and 0.034 S cm(-1) at 90 degrees C, whereas the pristine membrane exhibited conductivities of 0.019 S cm(-1) at 30 degrees C and 0.031 S cm(-1) at 90 degrees C. The membrane electrode assemblies were successfully fabricated for the pristine SPEEK and SP-CNT-FA-6 membranes, and their electrochemical performance was studied throughout the current density range. In addition to the favorable proton conductivity, the electrolyte membranes showed excellent thermal and mechanical stability; taken together, these results indicate that the composite membranes based on SPEEK with SWCNT and fly ash can be viable candidates for use as an electrolyte membrane in fuel cell applications.