Silica modified sulphonated Poly(ether ether ketone) proton exchange membranes for DMFC application

Herein, we report sol-gel modified sulfonated poly(ether ether ketone) (SPEEK) organosilane based composite proton exchange membranes for their suitability in direct methanol fuel cells (DMFCs). Different concentrations (0.2-1.5 wt%) of aminopropyl trimethoxysilane (APTES) are incorporated in SPEEK matrix by in-situ sol-gel method. Physico and electrochemical performances of composite membranes are enhanced by induced Hbonding interactions between free -NH2 and -SO3H groups. With increase in APTES concentration to 0.8 wt%, the ionic conductivity illustrates improvement by similar to 80% while IEC and Proton conductivity (Pc) enhances by similar to 21% and similar to 70%, respectively than SPEEK. To further explore the feasibility of the membranes in DMFC. Methanol crossover resistance is calculated to as low as 5.30 x 10(-7) cm(2) s(-1) and offers highest selectivity of 4.43 S s cm(-3) in contrast to 12.55 x 10(-7) cm(2) s(-1) and 0.31 S s cm(-3) for SPEEK, respectively. This study reveals that the Si-SPEEK membrane is a potential alternate for DMFC. (c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

Sol-gel modified sulfonated poly(ether ether ketone) (SPEEK) organosilane-based composite proton exchange membranes were investigated for their suitability in direct methanol fuel cells (DMFCs). The addition of aminopropyl trimethoxysilane (APTES) in different concentrations improved the physico and electrochemical performances of the composite membranes by inducing H-bonding interactions between free -NH2 and -SO3H groups. The Si-SPEEK membrane showed potential as an alternate for DMFCs.