Superacidic Electrospun Fiber‐Nafion Hybrid Proton Exchange Membranes

A novel type of hybrid membrane has been fabricated by incorporating superacidic sulfated zirconia (S‐ZrO 2 ) fibers into recast Nafion for proton exchange membrane fuel cells (PEMFCs). With the introduction of electrospun superacidic fiber mats, a large amount of protogenic groups aggregated in the interfacial region between S‐ZrO 2 fibers and the ionomer matrix, forming continuous pathways for facile proton transport. The resultant hybrid membranes had high proton conductivities, which were controlled by selectively adjusting the fiber diameter and fiber volume fraction. Consequently, the superacidic S‐ZrO 2 electrospun fibers are promising filler materials and hybrid membranes containing S‐ZrO 2 fiber mats can be potentially used in high‐performance fuel cells.