Fabrication and electrolyte characterization of uniaxially-aligned anion conductive polymer nanofibers

We report the anion transport properties of anion conductive polymer nanofibers fabricated using an electrospinning method. The aligned nanofibers were prepared to evaluate the anion conductivity of the nanofibers. The aligned nanofibers had 10-15 times higher conductivity (up to 160 mS cm^-1 at 90 °C and 95%RH) and lower activation energy (23-25 kJ mol^-1) than the corresponding membranes, even though the nanofibers showed lower water uptake than the corresponding membranes. The anion conductivity measurement of nanofibers with different IEC values and anion species revealed that the dependency of anion conductivity on these factors was smaller in the nanofibers than in the corresponding membranes. These results indicate that effective ion transport pathways were formed in the nanofibers due to the phase separation and the polymer chain orientation along the nanofiber axis. These nanofibers are expected to be useful for future applications in alkaline fuel cells, air batteries, and other energy- and environment-related devices regardless of the ion species.