Challenge

The transport sector is still dependent on fossil fuels and accounts for around 15 per cent of global carbon dioxide emissions. As high power densities and a long service life are important in this sector, hydrogen polymer electrolyte membrane fuel cell propulsion is a real alternative.  In contrast to batteries, it is scalable in the required dimensions, does not have long charging times, offers a higher system efficiency compared to alternative fuels, and is also emission-free on a local level. The fact that there have not been more hydrogen trucks on the roads for a long time is due to the high acquisition costs and the lack of infrastructure, as well as the ageing of the fuel cells. This problem can only be solved once the underlying deactivation processes have been understood under realistic operating conditions and effective condition monitoring measures have been established.

Goals and procedure 

In the SMART-H2 project, a laboratory test rig is being developed to systematically analyse the ageing of the fuel cell. A comparison with synchronised tests carried out in industrial test benches on fuel cell systems of up to 100 kilowatts enables the project team to develop accelerated ageing tests and regeneration measures. In addition, a method based on electrical impedance tomography (EIT) is being developed to characterise the ageing of fuel cell membrane units with spatial resolution. This method is to enable onboard monitoring of fuel cell systems in a vehicle. The modelling and simulation of cell ageing is being carried out together with the cooperation partner MAN Truck & Bus for real driving operations in order to develop an efficient control system for cells.

Innovations and perspectives

The deactivation of fuel cells in commercial vehicles has been insufficiently researched to date. The application of EIT at fuel cell sites envisaged in this project – a non-invasive imaging method used to determine the two- or three-dimensional distribution of impedance on the surface – is unique to date and can bring a decisive breakthrough, especially if the implementation of onboard monitoring is successful. Another innovation of the project is the approach of using synchronised laboratory and industrial tests to develop and understand practical ageing tests for commercial vehicles. The accelerated ageing tests, analysis methods, and prediction models developed in the project can also be applied to the investigation of other electrochemical energy converters such as battery cells and electrolysers.