1 Department of Energy Conversion and Storage, Technical University of Denmark2 Electrofunctional materials, Department of Energy Conversion and Storage, Technical University of Denmark3 Risø National Laboratory for Sustainable Energy, Technical University of Denmark4 Aarhus University
Incorporating oxide thermoelectric (TE) materials into TE power generation modules necessitates study of the interfaces between the oxide TE elements and the interconnect materials used to transfer current between them. In this study, interfaces between pure nickel and undoped calcium cobaltate (Ca3Co4O9) have been formed directly by spark plasma sintering (SPS). An intermediate NiO phase is formed during the SPS processes, which grows during post-heating with Co entering from the cobaltate side to form a graded Ni1xCoxO interfacial layer. The electrical and thermal transport across these interfaces, as well as the long-term chemical stability of the intermediate layers, have been studied and are discussed.
Journal of Electronic Materials, 2013, Vol 42, Issue 7, p. 1661-1668