November 1, 2018 – October 31, 2021
ARRS - Slovenian Research Agency, J2-9441 (B)
Solid oxide electrolysis cells (SOEC) are electrochemical devices that convert excessive electrical energy directly into fuel components such as
hydrogen, syngas and methane, in a highly efficient and environmentally friendly manner. The non-polluting fuels can be further used for the
production of heat and electricity as well as for automotive applications.
High efficiency and, nonetheless, no need for rare materials like platinum or lithium like for application in low-temperature electrolyser or batteries, are just some of the attractive properties that make solid oxide electrolysis highly perspective. This comes at a price of high operating temperatures of ~550-900°C, long start-ups and a range of harmful chemical processes that degrade cells performance and affect its durability. Insufficiently long-term performance and yet poor durability are the major hurdles for broad SOEC commercialization. Apart from the quest for new materials that will help reduce the operating temperatures, the two fundamental problems remain open. One is insufficient understanding of the onset and anticipation of the degradation phenomena within electrolyte and electrodes. The other is the lack of reliable means to detect, recognise and accommodate the evolving degradation modes online (modus operandi) and hence take appropriate counteractions to prolong the operational life of these devices.
These two problems will be the focus of the underlying project in which the teams from TUG and JSI join efforts and complementary expertise. Such a project would be impossible without recent original results in regeneration of solid oxide devices by TUG on one hand and non-sinusoidal signal processing for health evolution obtained by JSI team on the other hand. TUG will conduct a campaign of life-long and accelerated run-to-failure tests in which novel characterisation techniques, relying on non-sinusoidal probing, will be employed. The latter, developed by JSI team, will be combined with novel statistical signal processing algorithms for on-line condition monitoring of the class of fractional order systems. This project aims to find a set of informative features capable to provide the fingerprint of the particular degradation mechanism.
Next, quite a difficult problem to be addressed, concerns the design of efficient counter-measures to avoid or slow down the degradation. There is no result in the SOEC domain available so far. The experience that IJS team gained in the design of mitigation action in solid oxide fuel cells will be utilised. The entire methodology will be assessed experimentally at TUG. An important outcome of the project is the fact that measurements recorded during the test will be publicly released, which will be the first publically available data from SOEC durability tests so far. This research project will go beyond the current state-of-the-art in both new pieces of evidence of SOEC degradation mechanisms, as well as a novel, to date unavailable, methods of monitoring SOEC systems online. These principles will allow gaining fundamental knowledge of different degradation mechanisms, which can induce the irreversible deterioration of the cells’ microstructure and performance. Using new instances of system characterization beyond the conventional electrochemical impedance spectroscopy will push SOEC system control beyond the current state-of-the-art by changing the approach from one of failure detection approach to the detection of each of several simultaneously occurring failures, their prediction and prevention.