This Focus Review provides an overview of our recent study and related work on ion conductive polymer nanofibers and their applications in polymer electrolyte fuel cells. We succeeded in evaluating the intrinsic proton and anion conductivity of electrospun nanofibers and revealed their distinguished ion conductive properties, which were quite different from those of the corresponding polymer membranes. These ion conductive nanofibers have potential utility as polymer electrolyte composite membranes to improve fuel cell performance by utilizing efficient ion conduction both inside and at the surfaces of nanofibers.
