Hybrid Proton-Exchange Membrane Based on Perfluorosulfonated Polymers and Resorcinol-Formaldehyde Hydrogel.

Alexandra Maria Isabel Trefilov,Adriana Balan,Ioan Stamatin

doi:10.3390/polym13234123

Alexandra Maria Isabel Trefilov, Adriana Balan + Show 1 more

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https://doi.org/10.3390/polym13234123

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Abstract

Organic resorcinol–formaldehyde (RF) hydrogels were introduced into a hybrid cation-exchange membrane in order to enhance its following properties: water uptake, thermal stability, and ionic conductivity. This study was aimed to investigate the modifications induced by the RF organic clusters that form a uniform distributed network within the perflourosulfonated acid (PFSA) matrix. RF concentration was controlled by resorcinol and formaldehyde impregnation time using water or ethanol solvents. The specific morphological and structural properties were characterized by atomic force microscopy, UV–Vis, and Fourier transform infrared spectroscopy. Thermo-gravimetric analysis was employed to study the thermal stability and degradation processes of the composite membranes. Proton conductivity, as a function of relative humidity (RH) at 80 °C, was measured using in-plane four-point characterization technique. Compared to the pristine membrane, the PFSA–RF hybrid membranes showed improved thermal stability at up to 46 °C and higher ionic conductivity for low RF content, especially at low relative humidity, when using ethanol-based solvents. Single fuel cell testing on RF-based membrane–electrode assembly revealed impeccable fuel crossover and power performance at 80 °C and 40% relative humidity, delivering a 76% increase in power density compared to a reference assembled with a pristine membrane and the same catalyst loadings.

Highlights

Conventional energy sources using fossil fuels are the main environmental pollution cause
The SE1 membrane showed significantly improved performance in the single-cell polymer electrolyte membrane fuel cells (PEMFCs) under low humidity conditions (157 mW cm−2 compared to 89 mW cm−2)
The present study tested the hypothesis of using organic RF gels as dopants in a hybrid cation-exchange membrane in order to increase water uptake, thermal stability, and ionic conductivity

Summary

Introduction

Conventional energy sources using fossil fuels are the main environmental pollution cause. A flagship in PEMFC was introduced: the aerostack [7], which is a new concept in water-management technology that when combined with a self-humidifier membrane and high-performance lightweight materials can raise the power density up to 1 W g−1. This shows that there is enough room for improvement such as new filtration membranes for low hydrogen purity or new engineered perfluorosulfonic acid (PFSA) membranes with more than one sulfonic group on the Polymers 2021, 13, 4123 can raise the power density up to 1 W g−1. TThhee rraattiioo,, mmoollee ppeerrflfluuoorriinnaatteedd ssuullffoonniicc ggrroouuppss//mmoollee PPTTFFEE((eeqquuiivvaalleennttwweeigighht,t,EEWW))ddeteetremrminineethtehethtehremrmalaalnadnmd mecehcahnaicnailcastlasbtailbitiyl,iiotyn,-eioxnch-eaxncgheancagpeaccaiptyac(iItEyC(I=EC10=001/00M0/eM), ew),awteartuerputapktea,kteh,ethperoptroontocnoncodnudctuivctiitvyit[y12[–1124–]1.4]

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