Status and results of the project
Status after the first year
The best available state-of-the-art cells of the participating cell manufactures have been evaluated on performance and endurance. It appears that the performance of the reference cells is closer to the target values than expected, while on the other hand, the degradation rates are higher than expected. During the first year of the project the cell related activities focussed on the identification and characterisation of new materials and the optimisation of composition and microstructure of known materials for operation around 600oC. Some options assessed demonstrated performance close or even better than the target value. However, also for these candidate new/optimised components the (very limited) degradation data obtained show higher than expected degradation rates.
Most of the common (cheap) stainless steels considered candidates for the interconnect showed very low corrosion rates at 600C, both at oxidant as well as fuel (H2O/H2 = 2) conditions; sufficient for lifetimes far over 40 000 hours. Interconnect steel/coating combinations tested up to 1 000 hours showed values of the initial ASR and the ASR increase with time at 600oC, that are rather close to target values.
Known glass-ceramic seal materials, generally applied for 800oC stack operation, were shown to function well or even better, specifically concerning the interaction with the steel interconnect, at 600oC. The relatively large volume fraction of remaining glass phase might enable a healing treatment by re-heating the stack. On the other hand it was recognised that the required high-temperature treatment for this type of seals might damage stack components optimised for low-temperature operation and therefore the focus has shifted to compositions that allow settling at low temperatures. Metal and metal-composite seal options have been identified and designed that will be evaluated experimentally in the next year.
A Flame-Spray process for manufacturing (near) nano-sized powders (cathode, electrolyte and contact coating materials) has been developed and installed. Manufacturing trials showed yielded good results and first deliveries of powders to project partners have been done.
For testing and assessment single cells and short stacks partners have established/adapted their test facilities. All test capacity in the project is operational. Test procedures based on FCTESTnet/FCTESqa protocols have been formulated that are applied by all the partners. First full cell evaluations of reference cells and cells with integrated new components have been executed. Operation of a reference stack started shortly in the next reporting year.
The project organised the first workshop on the subject of test procedure and impedance spectroscopy as a means to measure ASR values of cell components. The workshop was open to SOFC600 and RealSOFC participants. Two external experts were invited for presenting their vision on the topic and for discussing the procedures proposed by the project partners.