Contact

How fuel cell membranes degrade

By

September 15, 2020

Image titel:

Sources:

How fuel cell membranes degrade

test setup
Test setup, © Fraunhofer ISE

Understanding how the presence of cations causes polymer electrolyte membranes to degrade is important to advancing PEM research. Fraunhofer ISE has been focused on analyzing various types of cations for their impact on perfluorosulfonic acid (PFSA) membranes. This analysis is significant in understanding the catalytic effect individual cations have on forming radicals that attack PFSA polymers. How chemical stable these polymers are was investigated using Fenton’s reaction.

This ex-situ method for accelerated chemical degradation employs an ion-selective electrode (ISE) to measure fluoride ion (F) release and determine the fluoride emission ratio (FER). It can be used together with other methods such as NMR, ATR-IR and Raman spectroscopy to analyze PFSA polymer degradation.

Advertisements

One of the main challenges to ensuring that PEM fuel cells remain stable is how to retain membrane durability. Due to their excellent stability, perfluorosulfonic acid (PFSA) membranes are now widely used in PEMFCs [1]. And yet, some conditions may cause membranes to become thinner or pinholes to form [1, 2], which increases gas crossover and can lead to lower performance or create safety issues [3].

A membrane can degrade chemically when hydroxyl (•OH) or hydroperoxyl (•OOH) radical species attack its polymer material [2]. These radicals form during oxygen reduction reactions or the decomposition of hydrogen peroxide (H2O2), which is created under certain conditions and in secondary reactions inside a PEMFC [2, 3]. For example, in open circuit (where electrodes are supplied with reactant gases but no current is drawn) and dry conditions, H2O2 forms from gases crossing the membrane, especially at the anode, because of existing potential [3, 4]. The process by which oxygen or hydrogen permeates the very thin membrane is called gas crossover. Although it is undesirable, it is an inevitable part of operating PEMFCs [3]. Since it creates H2O2 and, ultimately, radicals that attack the membrane and increase the crossover of gases, the negative effects become more pronounced over time.

Advertisements

When catalysts are absent, the rate of H2O2 decomposition is comparatively low. By contrast, transition metal ions can accelerate decomposition and create •OH and •OOH radicals that will degrade membranes relatively quickly. Iron cations (Fe2+) are known to be a particularly effective catalyst when breaking down H2O2 [5, 6]. The catalytic effect of any cation other than iron is rarely discussed in the literature, despite the fact that the water in PEMFC stacks contains various kinds of cations. They originate from, for example, assembly materials or salts contained in air humidifiers and enter the system during operation [7, 8]. Although most of them are present in low concentrations, they can still accelerate polymer degradation within the membrane.

read more in H2-international August 2020

Authors:
Sebastian Prass
Dr. Anneke Georg
Dr. Nada Zamel, all for Fraunhofer ISE, Freiburg, Germany

Here are interesting and current articles on the topic of hydrogen – stocks and the stock market!

Economic prospects for companies in the hydrogen sector | Future, stocks & hydrogen companies on the stock exchange and more…

Which hydrogen companies will prevail in the competitive market in the long term? Get tips and cartwheels and learn more about risks or opportunities. Our stock market specialist and expert author Sven Jösting reports critically, independently and competently.

Mar 18 2024

Search for the ideal hydrogen storage

Interview with Thomas Korn, CEO of water stuff & sun Startup company water stuff & sun has...
Mar 15 2024

Is exponential growth slowing down?

Fuel Cell Industry Review 2022 Year 2022 saw fuel cell shipments creep up over 2021 numbers,...
Mar 11 2024

On the way to becoming a green hydrogen partner

Oman aims to score points with H2 infrastructure Wind, sun and loads of expertise – these...
Mar 07 2024

We can master a scale-up for green hydrogen

Interview with Dr. Kai Fischer, Director at RWTH Aachen The efficient scaling of green hydrogen...
Mar 07 2024

Frustration over continuing uncertainties

Interview with Jorgo Chatzimarkakis, CEO of Hydrogen Europe There is a lot that needs sorting out...
Mar 05 2024

“If ever there was momentum for hydrogen, it is now”

Interview with Dr. Jochen Köckler, chairman of Deutsche Messe “We’re bringing people together.”...
Feb 28 2024

H2Direkt: Blueprint for heating with pure H2

The energy providers Thüga und Energie Südbayern (ESB) as well as Energienetze Bayern have...
Feb 26 2024

Just switch over?

Hydrogen in the existing natural gas network Whether hydrogen contributes to the clean heating...
Feb 26 2024

Pilot plant for coating bipolar plates

At Fraunhofer FEP (Fraunhofer-Institut für Organische Elektronik, Elektronenstrahl- und...
Feb 20 2024

55 MW electrolyzer to decarbonize Saarland

Hydrogen Regions series: HydroHub Fenne living lab The power plant site in Fenne, Völklingen, a...
Feb 20 2024

Chicken feathers as FC membrane material

Feathers from chickens or other poultry could in the future help make fuel cells more effective...
Feb 15 2024

SMEs demand more security

Guest article by André Steinau, CEO of GP Joule Hydrogen After all, the Ampel Coalition leading...
Feb 15 2024

Accelerated expansion of renewable energies

RED III is here – Elsewhere, the wait continues Progress is being made at EU level – albeit...
Feb 12 2024

Picea 2 relies on lithium instead of lead

HPS presents new product generation The company HPS Home Power Solutions has unveiled a new...
Feb 12 2024

H2 production by photocatalysis

The direct generation of hydrogen from sunlight has long been considered the most elegant solution...
Feb 05 2024

Regional instead of international

Hy-Fcell has it difficult asserting itself The aspiration of Landesmesse Stuttgart with Hy-Fcell...
Feb 01 2024

Hydrogeit Verlag turns 20 years old

Hydrogeit Verlag is proudly celebrating its 20th anniversary as a renowned specialist publisher in...
Jan 26 2024

Stracke other H2Now managing director

BMV Energy GmbH is entering the market as another player in hydrogen refueling stations. The...
Jan 26 2024

Starting points for a comprehensive hydrogen ramp-up

Industry congress GAT 2023 in Cologne To establish a functioning hydrogen economy, the entire...
Jan 26 2024

The industry highpoint in autumn

Hydrogen Technology Expo total success In autumn 2023 as well, the Hydrogen Technology Expo was...

0 Comments

Leave a Reply