Preparation and Characterization of Phosphoric Acid-doped Blend Membrane Composed of Sulfonated Poly(arylene ether sulfone) and Polybenzimidazole for Fuel Cell Application

A phosphoric acid (PA)-doped blend membrane composed of sulfonated poly(arylene ether sulfone) (SPAES) and polybenzimidazole (PBI) was developed for fuel cell application. Blending of SPAES and PBI improved its dimensional stability and gas barrier properties due to the acid-base interaction. Although the proton conductivity of the blend membrane was lower than that of the pristine SPAES membrane, the PA-doping redeemed its disadvantage to show enough high proton conductivity comparable to the conductivity of the Nafion membrane even at low relative humidity. The novel acid-doped blend membrane has a potential application for future fuel cells.