Functionalized Graphene Oxide Incorporated in Sulfonated Poly Ether Ether Ketone for Proton Exchange Membrane Fuel Cell Application

Abstract

As concerns grow over the depletion of fossil fuel sources and the effects of climate change, fuel cell technology has gained widespread attention for its excellent energy efficiency and low emissions. These devices operate as electrochemical systems that directly transform the chemical energy of fuels like hydrogen into electrical energy, bypassing the need for combustion. Proton exchange membrane fuel cells (PEMFCs) utilize polymer electrolyte membranes (PEMs) to facilitate proton transport. Among these, Nafion is one of the most widely used membrane materials in PEMFC applications. Nafion is one of the most commonly used polymer membranes in PEMFCs. However, Nafion presents several limitations, including relatively low proton conductivity, complex fabrication procedures, and a narrow operational window that demands elevated temperatures and continuous water regulation to maintain optimal performance. This study focuses on developing a composite membrane by incorporating sulfonated graphene oxide (SGO) into sulfonated poly(ether ether ketone) (SPEEK), aiming to improve the performance of single-cell PEMFCs when compared to the standard Nafion® 117 membrane by evaluating the membrane's physical and electrochemical properties. The fabrication of 10 wt. % of SPEEK and SGO/SPEEK dope solutions with different loading of GO & SGO (0.15, 0.20, 0.25 wt. %) via direct blending method followed by casting method. Scanning electron microscopy (SEM) was employed to identify the morphological structure of the filler incorporated membrane and several other test like ionic exchange capability and water uptake and FTIR was conducted to determine the ion capacity upon incorporation of SGO nanomaterial in SPEEK membrane. Hence via the functionalization of graphene oxide by sulfonation at 0.15 wt. % incorporated in SPEEK membrane proved to display better characteristics that suffice better as a PEM compared to bland SPEEK membrane and nonfunctionalized GO.