Research Interests

Chemical looping combustion
Materials that can absorb and release large quantities of oxygen find many current and potential applications in process industry, catalysis og carbon capture. We work on developing conceptually new materials with improved kinetics and capacity for oxygen storage and release with emphasis on crystal chemistry and thermodynamics.

All oxide thermoelectrics
Thermoelectric devices are a combination of materials with n- and p-type electronic conductivity and possess the ability to convert heat directly into electrical energy by the Seebeck effect. For high temperature applications in ambient atmosphere the state-of-the-art metal based thermoelectric devices are ruled out due to oxidation and melting. We are studying and developing all oxide thermoelectric materials and devices for applications at high temperatures in oxidizing atmosphere aimed at waste heat harvesting and sensors in harsh environments.

Dielectrics for sea cables
Electrification in general and the development of offshore wind demands new materials and design for high voltage insulation and sea cables. We are studying and developing materials for sea cables and high voltage insulation. We are focusing on composites and polymeric materials and are especially focusing on break down mechanisms. We are a part of the Ocean Grid project through the Green Platform scheme.

Windmills and anti-icing
Surfaces free of ice is important for several applications, including windmills. Icing on blades will influence the performance and must be avoided. We are working on solutions for passive anti-icing coatings and coatings with low adhesion to ice. Tailoring the surface chemistry is important in combination with the structure of the surface. Our activities also include testing of the coating performance.

Thermal energy storage and solid -state heating and cooling
The supramolecular material family that possesses an unusually high entropy solid-solid phase transition prior to melting are known as plastic crystals due to the plastic formability. In these materials, the orientational freedom of the molecular components is unlocked at the phase transition causing a large increase in entropy while still maintaining the long-range crystallographic order of a crystalline material. This affords unique opportunities to store thermal energy from waste heat or sources that are periodically available, such as sunlight, and release it later when it is needed. Our research so far in this field has focused on fundamental structure and property investigations around the phase transitions as a function of temperature using in situ X-ray diffraction at specific temperature (a) and as a function of temperature to make detailed temperature dependent structural maps (b). By determining the precise structural mechanisms that underpin the entropy changes at the phase transition we will be able to develop engineering approaches to modify materials for different applications.

HT- corrosion and corrosion protection
We have mainly focused on metallic interconnects in SOFC/SOEC. Different types of steel and their response in both oxidizing and reducing atmosphere have been in focus, as well as the effect of the protective coatings (composition and density) with respect to high temperature oxidation and Cr-evaporation. Additionally, the compatibility between the components in the device is crucial and is included as an important part in our studies.

Processing equipment:

• Tape caster
• Spin coater
• Spray coaters
• Dip Coater
• Evaporation techniques
• Spark plasma sintering unit (SPS)
• Planetary mill
• Hot uniaxial press

Characterization:

• Particle size distribution (PSD)
• BET
• Thermal analysis (TGA/DSC/MS/Dil)
• XRD/HTXRD
• Spectroscopy
• Mechanical strength (ball-on-ring)
• Inductively Coupled Plasma - Mass Spectroscopy (ICP-MS)
• Focused Ion Beam (FIB)
• Atom Probe Tomography (APT)
• Dielectric and piezoelectric testing of film and bulk samples
• Impedance spectroscopy
• In silico characterization by density functional theory (DFT) calculations

J. Walker, K. P. Marshall, J. Salgado-Beceiro, B. A. D. Williamson, N. S. Løndal, S. Castro-Garcia, M. S. Andújar, S. M. Selbach, D. Chernyshov and M.-A. Einarsrud
Mesophase transitions in [(C₂H₅)₄N][FeBrCl₃] and [(CH₃)₄N][FeBrCl₃] ferroic plastic crystals
ACS Chem. Mater. (2022)

M. M. Adnan, I.-E. Nylund, A. Jaworski, S. Hvidsten, M.-H. G. Ese, J. Glaum and M.-A. Einarsrud
The Structure, Morphology, and Complex Permittivity of Epoxy Nanodielectrics with In Situ Synthesized Surface-Functionalized SiO₂
Polymers 13 (2021) 1469

N. Kanas, R. Bjork, K. H. Wells, R. Schuler, M.-A. Einarsrud, N. Pryds and K. Wiik
Time-Enhanced Performance of Oxide Thermoelectric Modules Based on a Hybrid p-n Junction
ACS Omega 6 (2021) 197-205

S. P. Singh, N. Kanas, T. D. Desissa, M.-A. Einarsrud, T. E. Norby and K. Wiik
Thermoelectric properties of non-stoichiometric CaMnO₃-δ composites formed by redox-activated exsolution
J. Eur. Ceram. Soc. 40 (2020) 1344-1351

B. Talic, H. Falk-Windisch, V. Venkatachalam, P. Vang Hendriksen, K. Wiik and H. L. Lein
Effect of coating density on oxidation resistance and Cr vaporization from solid oxide fuel cell interconnects
J. Power Sources 354 (2017) 57-67.

V. Thoréton, M. Pishahang, T. Mokkelbost, K. Wiik, and Y. Larring
Microstructural stability of tailored CaMn_0.875−xFe_xTi_0.125O_3−δ perovskite oxygen carrier materials for chemical looping combustion
Energy Technology 5 (2017) 1579-1587