Imidazolium-Quaternized Poly(2,6-Dimethyl-1,4-Phenylene Oxide)/Zeolitic Imidazole Framework-8 Composite Membrane as Polymer Electrolyte for Fuel-Cell Application.

Thabakgolo T Letsau,Phumlani F Msomi,Penny P Govender

doi:10.3390/polym14030595

Thabakgolo T Letsau, Phumlani F Msomi + Show 1 more

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https://doi.org/10.3390/polym14030595

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Journal: Polymers	Publication Date: Feb 1, 2022
Citations: 7	License type: CC BY 4.0

Affiliation: University of Johannesburg

Abstract

Anion exchange membrane fuel cells (AEMFCs) are considered superior to their counterpart proton exchange fuel cells due to their many advantages. Both fuel cells use membranes as polymer electrolytes to improve fuel-cell properties and power output. This work evaluates a series of imidazolium-quaternized poly(2,6-dimethyl-1,4-phenylene oxide) (ImPPO) functionalized zeolitic imidazole framework-8 (ZIF-8) (ImPPO/ZIF-8) as anion exchange membrane (AEM) electrolytes in a direct methanol alkaline fuel cell. FTIR and 1H NMR were used to confirm the successful membrane fabrication. SEM and TGA were used to study the morphological and thermal stability properties of the ImPPO/ZIF-8 membranes. The AEMs obtained in this work had contact angles ranging from 55.27–106.73°, water uptake from 9–83%, ion exchange capacity (IEC) from 1.93–3.15 mmol/g, and ion conductivity (IC) from 1.02–2.43 mS/cm. The best-performing membrane, ImPPO/3%ZIF-8, showed a water uptake of up to 35% at 80 °C, a swelling ratio of 15.1% after 72 h, IEC of 4.06 mmol/g, and IC of 1.96 mS/cm. A power density of 158.10 mW/cm2 was obtained. This makes ZIF-8 a good prospect as a filler for enhancing membrane properties.

Highlights

The burning of coals, heavy oils, and petroleum to produce energy has bad consequences such as air pollution, energy security concerns, and climate change
The presence of strong peaks at 2θ = 7.30, 10.35, 12.70, 14.80, 16.40 and 18.00◦ correspond to planes (110), (200), (211), (220), (310) and (222), respectively. They indicate that zeolitic imidazole framework-8 (ZIF-8) is a crystalline structure, which agrees with the sodalite structure of ZIF-8 [25,27]
The membrane fabricated in this study showed better power output compared to other membranes of a similar kind despite being studied at 25 ◦C

Summary

Introduction

The burning of coals, heavy oils, and petroleum to produce energy has bad consequences such as air pollution, energy security concerns, and climate change. This has increased interest in finding alternative clean and secure energy sources. Fuel-cell technology (that converts chemical energy into electrical energy) has been viewed as an alternative energy source that guarantees clean and secure energy production within the EECSS. Their applications include use in transportation, portable devices, and microgrids. Direct methanol fuel cells are frequently used owing to their easy storage of fuel, can be operated for a longer period as long as the fuel cell is available and at elevated energy production [2,3,4,5]

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