A comprehensive study on improved power materials for high-temperature thermoelectric generators

authored by
Michael Bittner, Nikola Kanas, Richard Hinterding, Frank Steinbach, Jan Räthel, Matthias Schrade, Kjell Wiik, Mari Ann Einarsrud, Armin Feldhoff
Abstract

Dense Ca3Co4O9-NaxCoO2-Bi2Ca2Co2O9 (CCO-NCO-BCCO) nanocomposites were produced from sol-gel derived Ca2.25Na0.3Bi0.35Tb0.1Co4O9 powder by four methods: Hot-pressing (HP), spark plasma sintering (SPS) and pressureless sintering in air or O2 atmosphere. Nanocomposites from HP and SPS revealed nanosized grains and showed a thermoelectric power factor of 4.8 and 6.6 μW ⋅ cm−1 ⋅ K−2, respectively, at 1073 K in air. A dense 2D nanocomposite with structures on multiple length scales and enhanced thermoelectric properties was obtained from pressureless sintering in O2 atmosphere. The resulting 2D nanocomposite enabled the simultaneous increase in isothermal electrical conductivity σ and Seebeck coefficient α, and showed a thermoelectric power factor of 8.2 μW ⋅ cm−1 ⋅ K−2 at 1073 K in air. The impact of materials with enhanced electrical conductivity and power factor on the electrical power output of thermoelectric generators was verified in prototypes. A high electrical power output and power density of 22.7 mW and 113.5 mW ⋅cm−2, respectively, were obtained, when a hot-side temperature of 1073 K and a temperature difference of 251 K were applied. Different p- and n-type materials were used to verify the effect of the thermoelectric figure-of-merit zT and power factor on the performance of thermoelectric generators.

Organisation(s)
Institute of Physical Chemistry and Electrochemistry
External Organisation(s)
Norwegian University of Science and Technology (NTNU)
Fraunhofer Institute for Ceramic Technologies and Systems (IKTS)
University of Oslo
Type
Article
Journal
Journal of Power Sources
Volume
410-411
Pages
143-151
No. of pages
9
ISSN
0378-7753
Publication date
15.01.2019
Publication status
Published
Peer reviewed
Yes
ASJC Scopus subject areas
Renewable Energy, Sustainability and the Environment, Energy Engineering and Power Technology, Physical and Theoretical Chemistry, Electrical and Electronic Engineering
Sustainable Development Goals
SDG 7 - Affordable and Clean Energy
Electronic version(s)
http://hdl.handle.net/11250/2580784 (Access: Open)
https://doi.org/10.1016/j.jpowsour.2018.10.076 (Access: Closed)