Together with the ZBT – Center for Fuel Cell Technology in Duisburg and the industrial partners AGC Chemicals Europe, Bürkert Fluid Control Systems, ContiTech Deutschland, Mitsui Chemicals Europe and Treffert GmbH & Co. KG, the Plastics Center – SKZ has successfully completed the industry-funded research project “EVOPLAST” for the qualification of plastics for fuel cell systems.
Hydrogen – especially in combination with fuel cell technology – is regarded as a key technology for a sustainable energy future. It enables high levels of efficiency, operates with zero local emissions and can be flexibly combined with renewable energies. Fuel cells score particularly well in mobile applications such as vehicles, buses, trains and ships thanks to their long range and short refueling times compared to battery electric drives. They offer additional advantages in heavy goods traffic and commercial vehicles, as weight and charging times are decisive factors. Fuel cells also make an important contribution to the energy transition in stationary applications – for example for decentralized power and heat generation in buildings, data centers or as an emergency power supply.
Despite these advantages, widespread use and economic scaling still face challenges: Many materials and components in today’s fuel cell systems are too cost-intensive or too heavy. Targeted cost and weight reduction – for example through the increased use of plastics as substitute materials – is therefore essential.
Plastics play a central role in the construction of fuel cell systems. They are used in connectors, pumps, seals, pipes and many other components. As these plastics can come into direct contact with reactive media and therefore have a significant influence on the service life and functionality of the fuel cell, sound knowledge of media resistance, purity requirements and the suitability of specific additives is of crucial importance.
EVOPLAST: Plastics evaluation for fuel cells
In the EVOPLAST industrial project, which ran from May 1, 2023 to April 30, 2025, the SKZ Plastics Center and the Center for Fuel Cell Technology (ZBT) focused on the material-specific evaluation of plastics in the field of PEM fuel cells (Proton Exchange Membrane Fuel Cells). The aim was to define application-specific criteria in order to systematically support the selection of polymer-based materials with regard to media resistance, purity and long-term behavior.
Innovative in-situ test method for material evaluation
As part of the project, an in-situ test method developed by ZBT was used and further developed to qualify the influence of plastic materials on the behavior of fuel cells. The method is based on the targeted exposure of plastic samples under defined conditions in a test chamber, which can be integrated into either the cathode or anode supply line of the fuel cell.
The emissions released by the plastic samples are fed into a downstream fuel cell designed as a sensor cell. In this way, a direct correlation between the emitted substances and their potential effects on the electrochemical performance of the fuel cell can be recorded.
“Especially for components in the fuel cell environment – such as valves, pipes or seals – materials must meet the highest requirements. With the in-situ measurement method, the influence of potentially desorbing emissions, such as volatile components from the material samples, can be analyzed and evaluated directly on the cell performance,” explains Dr. Ulrich Misz from ZBT.
Test protocol for industrial practice
The in-situ analysis was supplemented by ex-situ investigations using gas chromatography (GC) and mass spectrometry (MS) in order to precisely identify the type and concentration of the emitted substances. In the course of the project, a test protocol specifically tailored to the requirements of fuel cell systems was also developed and successfully implemented with a view to potential end applications.
“The combined approach of in-situ performance evaluation and ex-situ emission analysis enabled a comprehensive assessment of material compatibility,” says Alexander Rusam, Project Manager and Scientist Material Development & Testing at SKZ.
Conclusion
1. Heterogeneity in the emission behavior of the polymers
The tests showed that the plastics used caused very different power losses in the fuel cell despite the same test conditions. The measurement results of the voltage loss ranged from 0 %, i.e. without the slightest influence, to 50 % or total failure with regard to the overall performance within a few hours.
2. better understanding of the correlation between material composition and degradation
In the course of the project, it was found that the same base materials from several partners produced very different in-situ results. This confirmed the hypothesis that even small amounts of additives – such as additives, fillers or stabilizers – can influence the desorption behaviour and lead to an increased degradation rate in the fuel cell.
3. transfer of the findings to industrial process chains
The participating companies used the data obtained to systematically refine their range of materials and adapt them to specific applications. To this end, the project developed and tested a pre-treatment step to potentially reduce emissions. Suggestions were given for optimizing the processing parameters in the manufacturing process.
Further research projects planned
The knowledge gained from the industry-funded project forms a sound basis for further research activities. The SKZ Plastics Center and the ZBT are currently preparing an IGF follow-up project in which in-depth investigations into material technology and system-relevant issues are to be carried out. Interested companies are cordially invited to participate in this forward-looking project in the project committee. The SKZ will be happy to answer any queries and provide further information.
Emission chamber developed by the ZBT and used in the project for different types of material (left) and the test stand for material qualification at the ZBT (right). (Source: Center for Fuel Cell Technology (ZBT)