Novel Nanocomposite PEM Membranes with Continuous Proton Transportation Channel and Reinforcing Network Formed by Electrospinning Solution Casting Method

Abstract In this work, a kind of novel nanocomposite proton exchange membranes (PEMs) with excellent properties for fuel cell application is obtained through the combination of electrospinning and solution casting. PEMs are obtained via the electrospinning of solution of sulfonated poly(arylene ether ketone)s (SPAEK)s with carboxylic acid group (SPAEK‐COOH) inserted with nanocrystal cellulose (NCC) first, and then, the SPAEK‐COOH solution is cast on the obtained electrospinning membrane to fill the voids. According to the scanning electron microscopy image of the membrane surface and freeze‐fractured cross section, the nonporous membrane was successfully obtained. The water uptake and the swelling rate of the nanocomposite membrane with 2% NCC (NF‐NCC2) decrease to 62% and 61.5%, respectively, and the membrane shows much higher proton conductivity (0.29 S cm −1 ) than the pristine SPAEK‐COOH membrane (NF‐NCC0) (0.196 S cm −1 ) at 100 °C. Furthermore, NF‐NCC2 shows a tensile strength of 38 MPa, which is an increase of 36% compared to NF‐NCC0 (28 MPa). The orderly and uniform distribution of NCC in the electrospinning nanofiber and further in the membranes.