A Robust Composite Proton Exchange Membrane of Sulfonated Poly (Fluorenyl Ether Ketone) with an Electrospun Polyimide Mat for Direct Methanol Fuel Cells Application

Abstract

As a key component of direct methanol fuel cells, proton exchange membranes with suitable thickness and robust mechanical properties have attracted increasing attention. On the one hand, a thinner membrane gives a lower internal resistance, which contributes highly to the overall electrochemical performance of the cell, on the other hand, strong mechanical strength is required for the application of proton exchange membranes. In this work, a sulfonated poly (fluorenyl ether ketone) (SPFEK)-impregnated polyimide nanofiber mat composite membrane (PI@SPFEK) was fabricated. The new composite membrane with a thickness of about 55 μm exhibited a tensile strength of 35.1 MPa in a hydrated state, which is about 65.8% higher than that of the pristine SPFEK membrane. The antioxidant stability test in Fenton’s reagent shows that the reinforced membrane affords better oxidation stability than does the pristine SPFEK membrane. Furthermore, the morphology, proton conductivity, methanol permeability, and fuel cell performance were carefully evaluated and discussed.

Development of Sulfonated Poly(vinyl alcohol)/MoS2-Based Robust Composite Proton Exchange Membranes with Higher Selectivity

“…The methanol concentration was calculated by the cyclic voltammetry (CV) method, as presented in Figure S4. The methanol permeability was calculated using the following formula m ethanol permeability 0.25em ( P ) = l A × V C normalO × normalΔ C normalΔ t where P is the methanol permeability (cm 2 /s), l and A are the thickness (cm) and area (cm 2 ) available for permeation, respectively, V and C 0 are the volume (cm 3 ) and initial concentration (mol/L) of the methanol solution, respectively, and Δ C /Δ t is the slope of the curves of methanol concentration vs. time in chamber B.…”

A review on ion-exchange nanofiber membranes: properties, structure and application in electrochemical (waste)water treatment

“…Polyimide is known to have great mechanical properties and is, therefore, a good candidate for reinforcement [161,165,166]. Additionally, it has been reported by Lee et al that the presence of polyimide nanofibers can enhance dimensional stability as well.…”

“…However, a comparison of the proton conductivity between the reinforced and non-reinforced membranes was missing. In most cases, the presence of the non-conductive reinforcement fibers reduces the ion conductivity compared to the pure conductive matrix material [162,164,166,167,[169][170][171][172]]. An exception has been reported by Xu et al by using cellulose nanofibers in a sulfonated poly(ether sulfone) (SPES) matrix (Fig.…”

Recent Advances in Functional Polymer Materials for Energy, Water, and Biomedical Applications: A Review

“…These fuel cells have recently experienced great progress in their application for the production of electric vehicles [100,101]. Indeed, direct methanol fuel cells (DMFCs) have shown great potential in various energy applications, due to their energy conversion performance, high fuel portability, and eco-friendly aspects [102][103][104]. Several parameters influencing the efficiency of DMFCs have been reported, and the effects of the electrocatalysts used have been widely studied.…”