The fuel cell research center ZBT GmbH
Research
Fuel cell technology is being developed internationally by major automobile manufacturers, and its technical feasibility has long been established. There are nevertheless still many R&D topics to be addressed in order to improve lifetime and reduce costs. This applies as much to the expensive components for the fuel cell itself as to the system components and system architecture. An important success at the ZBT was the development of a 30 kW fuel cell stack with automotive capability that is designed to extend electric vehicle range. All the familiar international performance standards were met with the technology; in fact, a power density of 1 W/cm² of active electrode surface during operation in dry air for the cathode side of the stack is actually better than the standard. This development was made possible in a project funded by the state of North Rhine-Westphalia (NRW) with partners VKA of the RWTH Aachen, FEV and Gräbener Maschinentechnik. The fuel cell stack contains metallic bipolar plates from Gräbener, and it was integrated in a system and ultimately an electric Fiat 500 in Aachen. With the 300 bar hydrogen tank, the range extender will help to increase the range of the little runaround to 300 km. Work on the development is set to continue as part of a further collaborative project, with the aim of making this technology viable for routine deployment in a logistics company’s fleet.
Fuel cell systems have meanwhile also established themselves in cogeneration – at least in Japan, where over 130,000 have already been installed with end customers. If this environmentally friendly technology is to be successful on the market in Germany too, the market incentive programmes must be accompanied by further technological advances of the kind the ZBT is working on in consortium projects with renowned German and European companies. Reliable operation with liquid gas as an alternative to natural gas is one argument for establishing this technology also in rural areas. Important milestones, such as safe removal of harmful sulphur components from liquid gas, a compact, economical gas processor for the production of feed gas for the fuel cell, and efficient system design, are the responsibility of the ZBT in the collaborative project with the liquid gas company Primagas and systems developer New Enerday.
If the future energy supply system is to be significantly more flexible, it is essential that ways of storing energy are created. One option for increasing flexibility is to use the natural gas grid for synthetically generated methane for energy storage. The ZBT is working as part of the “Virtual Institute: Power to Gas and Heat” on behalf of the state of NRW on developing a demonstration facility for the production of synthetic methane (SNG) from hydrogen and carbon dioxide on the basis of catalytic methanation.
A further focus of research interest at the ZBT is innovative battery technology, including Li-ion, Zn-air and redox flow. In cooperation with the Nano Energy Technology Center at the University of Duisburg-Essen and the Chair of Energy Technology, innovative electrode materials were developed for Li-ion batteries; of these, the nanosilicon-based anodes deserve special mention, already withstanding over 500 cycles in continuous testing at a capacity of over 2000 mAh/g (five to six times more than conventional anode materials).