Research

Fuel cell vehicles, in addition to battery vehicles, are especially suitable for applications with long ranges and fast refuelling times, and are already being used for cars, buses, trucks and trains. Production lines have been established in Korea, Japan and China in particular. As a result, the development of production processes and quality assurance are becoming increasingly important; in the R&D work and services of the ZBT too. Fuel cell technology for vehicle drives has special requirements for power density – a compact design is crucial for integration into a passenger car. The ZBT has now developed and tested fuel cell stacks for automotive applications for and with various partners. The decisive factor here is the interaction between complex media flow and high power density on the one hand and manufacturability and cost structure on the other. The focus of the work at the ZBT is on bipolar plates, which supply the reaction zone with the fuels, the sealing technology and the membrane electrode assemblies (MEA) where the reactions takes place. The MEA is a layer system of anode, cathode and solid polymer electrolyte and is arranged between two bipolar plates. Research in the field of fuel cell technology is extremely diverse and ranges from improving the components in the fuel cell stack to investigating system aspects in real operation. Accordingly, the portfolio includes various characterisation methods and specially developed test rigs designed and set up by ZBT staff. Due to this long-standing experience, the ZBT can often offer special services that would not be possible with commercial test rigs. Electrochemical characterisation methods for fuel cells, batteries and electro­lysers, methods for modelling and simulation, for flow optimisation and a compound pilot plant are established in this way.

Another focus of the ZBT’s work is the construction of a hydrogen test field comprising electrolysis for hydrogen generation, compression and storage as well as a research filling station. Additionally, the establishment of a hydrogen analysis laboratory is being realised in which compliance with the strict quality requirements for hydrogen purity can be checked at the filling stations. The challenge here is to upgrade commercially available analyt­ical equipment to such an extent that the low limits of the standard can actually be measured reproducibly. In cooperation with the Centre for Solar Energy and Hydrogen Research ZSW in Ulm, the analytical methods will be evaluated and the results compared, thus creating two qualified laboratories in Germany. In order to be able to fulfil the task of checking hydrogen quality in practice, a sampling system has also been developed with which quality tests can be carried out at the almost 80 hydrogen filling stations in Germany. Even more important, however, are the following subjects:

the clarification of the question regarding damage mechanism and potential of individual contaminants,

the control of the necessity of thus keeping low levels of the concentration limits,

the development of a sensor system (in cooper­ation with the Heinrich Heine University of Düsseldorf) that can provide suitable protection for fuel cell vehicles, and adapted operat­ing and maintenance strategies.