ZBT scientists at EFCF 2025 in Lucerne

‘Laser-structured titanium foils as PTL in PEM-WE cells and the influence of porosity on mass transport properties on the anode side’

For many of those who followed ZBT scientist Sebastian Hirt’s presentation at the EFCF – European Electrolyser and Fuel Cell Forum, this presentation title will have been perfectly understandable. For everyone else, an explanation may be necessary:

What is a PTL? And what is the significance of the pores in the titanium foil?

The porous transport layer (PTL) is a central component of electrolysers, especially in proton exchange membrane water electrolysis (PEMWE).

It fulfils three important tasks:

• It transports water to the catalyst layer, where it is separated into protons and oxygen.
• It conducts the resulting gases away.
• It establishes electrical contact between the catalyst and the current collector. This is important because without electricity, there is no hydrogen.

The challenges in PTL development are complex:

• The PTL must be electrically conductive and offer the largest possible contact area with the catalyst layer to enable efficient electron transport.
• At the same time, high porosity is necessary so that water and gases can flow through the layer easily.
• These two requirements often contradict each other and require a sophisticated design.

Innovative laser drilling process

In the project MetalFoil-PTL the ZBT and the Chair of Laser Application Technology at the Ruhr-University Bochum are jointly focusing on the development of a laser drilling process for structuring titanium foils with the aim of enabling a cost-efficient PTL design.

It has been demonstrated that high-performance PTLs can be manufactured with minimal material usage. The laser-structured titanium foils specifically reduce mass transport losses while ensuring excellent electrical connection of the catalyst layer. This represents an important step forward for more efficient and economical PEM electrolysis cells.

Non-precious metal catalysts for the anode in PEM water electrolysis

One of the biggest challenges in scaling PEM water electrolysis is the heavy reliance on iridium-based catalysts, which are scarce and therefore very expensive. Although transition metal oxides offer a more sustainable and abundant alternative, their limited stability in acidic environments remains a key obstacle.

ZBT researcher Dr Vimanshu Chanda spoke in Lucerne about advances in this field: ‘Our ongoing work is investigating strategies to overcome these challenges by fine-tuning the composition of MnO₂ through strategic dotation to improve both activity and stability – thereby supporting efforts to reduce dependence on critical raw materials such as iridium,’ Vimanshu summarised his presentation.

Improving lifetime prediction for PEM electrolysers under real-world conditions

A reliable understanding of performance degradation is essential for the long-term deployment of electrolysers for green hydrogen production. However, due to fluctuating operating conditions and long time scales, it remains difficult to gain insights into ageing under real-world conditions.

At the EFCF, our researcher Florian Kuschel presented a data-driven approach developed in the Degrad-EL3 project for developing ‘predictive’ protocols for accelerated stress testing (AST).
This novel approach combines physical modelling and machine learning to enable more realistic predictions of performance degradation for different operating cycles.

The goal: improved prediction accuracy with significantly reduced testing time – a step towards more efficient qualification of electrolysis technologies.

New Materials and Technologies Department

ZBT scientist Florian Ansorge presents research results on the ‘H2-Fuel’ project

The current limits for impurities in hydrogen as a fuel do not take into account the current requirements of users. This poses the risk of reduced mileage and reliability characteristics of FCEVs that do not meet customer needs.

The aim of the H2-Fuel project was to create a data basis for the necessary adaptation of ISO 14687-2 for hydrogen dispensing quality at filling stations, taking into account current and future fuel cell configurations and the economic efficiency of the overall system.
ZBT scientist Florian Ansorge presented the results of our contribution to the project on a poster at the EFCF: We investigated load profiles for PEM fuel cells in order to be able to quantitatively determine the effects of hydrogen contamination on PEMFCs in the future.

Fuel Cell Systems Department