Researchers at DTU will monitor the reactions and processes in operating fuel cells and electrolysis cells at the nanoscale, observing weak spots as they evolve, making groundbreaking countermeasures possible.
Solid oxide fuel cells (SOFC) and solid oxide electrolysis cells (SOEC) are likely to play an important role in the energy infrastructure of the future, by transforming chemical energy into electricity and back again in an efficient and environmentally friendly way to minimize CO2 emissions.
But the cells are still struggling with cost and degradation, and to address those issues the Danish Council for Independent Research has granted a total of 8,952,480 DKK to the two research projects “In situ transmission electron microscopy on operating electrochemical cells” (TEMOC) and “Visualizing energy conversion pathways” (ECoProbe) at DTU Energy Conversion under the Technical University of Denmark.
"What we are trying to do in TEMOC is watch the processes live while they are actually happening and that hasn’t been done before"
Postdoc at DTU Energy Conversion, Søren Bredmose Simonsen
Individual projects
TEMOC and ECoProbe are individual projects, but they are highly complementary, as they bring together new advanced experimental techniques for nanoscale characterization in the harsh operating conditions of SOFC and SOEC (e.g. elevated temperatures, reactive gas environment), thereby improving fundamental understanding of catalytic processes, which can lead to improvements in their design and efficiency and, ultimately, to the wider deployment of advanced SOFC and SOEC technology.
“The nanoscaled structure and composition of degraded cells has been largely limited to analysis after tests are finished, breaking the cells apart and studying them under microscopes to make an educated guess as to what might have happened, where and when in the active cell. TEMOC and ECoProbe will enable us to monitor the microstructural and compositional changes as they happen, providing clear evidence as to why they happen”, says associate Professor Luise Theil Kuhn.
Postdoc at DTU Energy Conversion, Søren Bredmose Simonsen elaborates.
“What we are trying to do in TEMOC is watch the processes live while they are actually happening and that hasn’t been done before.”
To follow catalytic processes and structural and compositional changes of an operating cell at the nanoscale will be very challenging. But recent developments in Transmission Electron Microscopy (TEM), Scanning Probe Microscopy (SPM) and synchrotron-based X-ray Photoelectron Spectroscopy (XPS) have opened the way for the observation of operating cells using such devices.
DTU Energy Conversion has now teamed up with Japanese researchers from Nagoya University as well as researchers from Oak Ridge National Laboratory and Stanford University in USA to tread new grounds within in operando monitoring of SOFC and SOEC.
Better cells and less degradation
“ECoProbe will develop more sensitive probes for high-temperature scanning probe microscopy to visualize the microstructure and the distribution of the electrochemical reactions on real electrodes, and how they change while the test is running and as a function of the operating conditions. Furthermore, synchrotron-based XPS will help map the surface chemical composition of reactive intermediates, shedding light on the way these reactions take place and on what limits them, offering insight on ways to improve them.”, says postdoc Christodoulos Chatzichristodoulou, DTU.
At the same time TEMOC will develop new micro-fuel cell systems to be able to monitor the nanoscale processes, locating weak spots as they evolve and see the degradation.
Exact understanding of what happens where and when in the degradation processes of a cell will make it possible to enact countermeasures, again leading to better cells and less degradation.
“You may wonder why it hasn’t been done before, because it seems so obvious. The answer to that is that no one had the techniques and the equipment. But we have researched in fuel cells for many years at DTU Energy Conversion and in the process we developed prototype equipment and brand new techniques that we can use now”, says Professor Mogens Mogensen.
TEMOC and ECoProbe are both expected to be finished in 2017.