Pore-filled composite proton exchange membrane based on crystalline poly (ether ketone) with considerable comprehensive performance in direct methanol fuel cell system

Direct methanol fuel cells (DMFCs) represent a new generation of clean energy technology with great potential to become a dominant power source for future portable electronic applications. However, the crucial component of DMFCs, current proton exchange membranes (PEMs) often struggle to perform effectively in highly concentrated methanol solutions. To create membranes suitable for use in high-concentration DMFCs, a series of composite membranes using crystalline poly (ether ketone) (PEK) as matrix and high sulfonated poly (aryl ether ketone) (SPAEK) as filler were developed by pore-filling technology (PEK@SPAEK-x). The crystalline matrix allows the PEK@SPAEK-x membranes excellent dimensional stability, while the high sulfonation degree filler provides significant proton conductivity. At 80 degrees C, the proton conductivity of PEK@SPAEK-75 membrane reaches 154 mS cm(-1) , but its In-plane swelling ratio in water is only 15.32 %, and In-plane swelling ratio in methanol is only 8.57 % at 60 degrees C. Furthermore, the composite membranes PEK@SPAEK-x exhibit markedly decreased methanol permeability, roughly one-third that of the pure SPAEK-x membranes. In a direct methanol fuel cell (DMFC) with 10 M methanol as fuel, the peak power density of PEK@SPAEK-75 membrane finally achieves 49 mW cm(-2), demonstrating certain application potential in DMFC systems.