Enhanced proton conductivity of sulfonated poly(ether ether ketone) incorporating oxidized polyvinyl alcohol for high-performance proton exchange membranes

Abstract Alternative proton exchange membranes (PEMs) with high proton conductivity must be fabricated at reasonable costs to qualify as commercially used proton-exchange membrane fuel cells (PEMFCs). As a result, composite membranes containing sulfonated poly(ether ether ketone) (SPEEK) blended with various quantities of partially oxidized polyvinyl alcohol (OPVA) at 5 wt%, 10 wt%, and 20 wt% were developed for PEMs. At room temperature, the water uptake capacities of the SPEEK membranes containing 5, 10, and 20 wt% OPVA were 45%, 75%, and 109%, respectively. Correspondingly, the proton conductivities of SPEEK containing 5, 10, and 20 wt% OPVA were 22, 48, and 80 mS cm −1 at 110 °C, respectively. Compared with prestine SPEEK, OPVA/SPEEK have greater strength, stiffness, and thermal stability. The characterization results indicated that the strong hydrogen bond network that evolved between OPVA and SPEEK provided more jump sites for proton transfer. This study confirmed that OPVA/SPEEK membranes are effective as proton exchange membranes. Graphical abstract