Development of robust proton exchange membranes for fuel cell applications by the incorporation of sulfonated β-cyclodextrin into crosslinked sulfonated poly(vinyl alcohol)

Abstract

Despite significant advances in the development of proton exchange membranes for fuel cell applications, still there is a big challenge to enhance the mechanical strength and proton conductivity of the membranes to make the fuel cell technology affordable. Thus, present work describes the preparation of crosslinked sulfonated poly(vinyl alcohol) membrane using titanium glycine-N,N-dimethylphosphonate. It was then modified by incorporating the sulfonated β-cyclodextrin in different mass%. The resulting proton exchange membranes were subjected to various techniques to assess their physicochemical properties. The ion exchange capacity of the membranes was found to be in the range of 1.40 to 2.55 meq/g. The proton conductivity of the membranes was evaluated using a high precision impedance analyzer at different temperatures with 100% relative humidity. Membranes containing 16 and 20 mass% of sulfonated β-cyclodextrin demonstrated the excellent proton conductivity of 0.121 and 0.143 S/cm at 80 °C, respectively. The fuel cell performance study also suggests that membranes containing 16 and 20 mass% of sulfonated β-cyclodextrin exhibited the power density of 0.34 and 0.38 W/cm2, respectively. These values are much superior to the existing commercial Nafion® 117 membrane (9 mW/cm2). Thus, these two membranes considered as potential candidates for fuel cell applications.