High-temperature Electrochemical Impedance Spectroscopy Transmission electron microscopy on energy materials (HEIST)

Focused on pushing Solid Oxide Electrolysis Cell (SOEC) technology to a breakthrough, the HEIST project is developing a method for fully characterising SOEC materials and model cells, i.e. an integrated Transmission Electron Microscopy (TEM) and Electrochemical Impedance Spectroscopy (EIS) in-situ technique.


To mitigate global warming and its associated climate change, a great challenge for humankind is to replace fossil fuels with green and sustainable alternatives for energy production. Despite having no associated greenhouse gas emission and being renewable, solar and wind power still cannot outcompete fossil fuels as energy sources due to inconsistent supply. An efficient energy conversion and storage system is therefore necessary to store energy when there is an excess supply for use during calm weather.

One way to convert excess electrical energy to chemical fuels, which are suitable for storage, is through high-temperature solid oxide electrolysis cells (SOEC). This technology is well known and proven, but not price competitive with energy technologies based on fossil fuels because of the significant material degradation. To drive the SOEC research towards a breakthrough, it is therefore critical to get a thorough understanding of SOEC's degradation process, i.e. to determine the relationship between the electrochemical activity and the structure/composition in the cells.



To fully characterise the degradation process of SOEC, HEIST is working on developing an in-situ method that integrates Transmission Electron Microscopy (TEM) and Electrochemical Impedance Spectroscopy (EIS) using a MEMS chip. The method will then be used to characterise SOEC materials and model cells. The characterisation will provide “live” images of nanostructures and composition during operation of the electrochemical cells, along with its electrochemical behaviour, thus disclosing direct structure-activity relationship.