Recent Progress in the Development of Aromatic Polymer-Based Proton Exchange Membranes for Fuel Cell Applications

Abstract

Proton exchange membranes (PEMs) play a pivotal role in fuel cells; conducting protons from the anode to the cathode within the cell’s membrane electrode assembles (MEA) separates the reactant fuels and prevents electrons from passing through. High proton conductivity is the most important characteristic of the PEM, as this contributes to the performance and efficiency of the fuel cell. However, it is also important to take into account the membrane’s durability to ensure that it canmaintain itsperformance under the actual fuel cell’s operating conditions and serve a long lifetime. The current state-of-the-art Nafion membranes are limited due to their high cost, loss of conductivity at elevated temperatures due to dehydration, and fuel crossover. Alternatives to Nafion have become a well-researched topic in recent years. Aromatic-based membranes where the polymer chains are linked together by aromatic rings, alongside varying numbers of ether, ketone, or sulfone functionalities, imide, or benzimidazoles in their structures, are one of the alternatives that show great potential as PEMs due totheir electrochemical, mechanical, and thermal strengths. Membranes based on these polymers, such as poly(aryl ether ketones) (PAEKs) and polyimides (PIs), however, lack a sufficient level of proton conductivity and durability to be practical for use in fuel cells. Therefore, membrane modifications are necessary to overcome their drawbacks. This paper reviews the challenges associated with different types of aromatic-based PEMs, plus the recent approaches that have been adopted to enhance their properties and performance.

On the evolution of sulfonated polyphenylenes as proton exchange membranes for fuel cells

“…For overviews on hydrocarbon PEM materials, in general, including ionic polyaromatics containing heteroatoms in the main chain, the reader is directed to any number of excellent reviews on the topic. 14,15,33 For comprehensive summaries on current understanding and states-of-the-art of PFSA-based materials, the reader is directed to recent reviews by A. Kusoglu and A. Weber, 5 and M. Zatoń et. al.…”

Biohydrogen from Microalgae: Production and Applications

“…In a PEMFC, platinum is substituted by an ion exchange membrane that facilitates ion migration. This membrane is a polymer that usually has negatively charged group in order to let protons to flow toward cathode; but there also exists anion exchange membranes that hold positively charged groups so that the anion can be transported [76]. The most commonly used membrane is that made of perfluorosulfonic acid polymers-commonly known as Nafion ® .…”

Development and characterization of poly(oxy-1,4-phenylenesulfonyl-1,4-phenylene) for proton exchange membranes

“…The fuel cell's performance depends on the ability of the electrolyte transportation capacity of ions from the anode to the cathode [19]. This test was performed by the titration technique.…”

“…The membrane material in the fuel cells, impose a restriction in the temperature permissible to its performance. For example, commercial fuel cells, like Nafion by Dow-DuPont, that works below 100°C [19,23]. Hence, we use 60°C for this test, that is the closest temperature at which the commercial fuel cells work.…”