Results of experiments on BoP components

In order to evaluate and extend the lifetime of automotive PEM fuel cell systems, durability and performance losses of the balance of plant (BoP) components play a major role. BEG had the responsibility within the Giantleap project to analyze the lifetime degradation of the main BoP components and deliver measurement data accordingly. Focus lay on the cathode path components, air compressor and humidifier. For both, one sample was dismantled, analyzed and the ageing mechanisms identified. From this knowledge, a test bench set-up and according test cycle was developed. A 500-hour endurance run produced measurement data for further evaluation and design of operation strategies and layout criteria. This data now is available to the other project partners in the project e-room. The endurance test delivered the proof that the system designed for Giantleap is fit to at least perform during the demonstration period. At the same time, considerable weaknesses of the components became evident. Over the duration of the tests performed, the humidifier lost about 50% of its calculated efficiency, which leaves room for further investigation and verification. The performance of the compressor remained stable through the whole endurance run with one capital failure due to an inappropriate operation point. Nevertheless, the subliminal danger of contamination by spilled traction oil remains and leaves the opportunity for oil-free bearing technologies open.