TY - JOUR

T1 - A comprehensive study on improved power materials for high-temperature thermoelectric generators

AU - Bittner, Michael

AU - Kanas, Nikola

AU - Hinterding, Richard

AU - Steinbach, Frank

AU - Räthel, Jan

AU - Schrade, Matthias

AU - Wiik, Kjell

AU - Einarsrud, Mari Ann

AU - Feldhoff, Armin

N1 - Funding Information: This work has been funded by the Deutsche Forschungsgesellschaft ( DFG, German Research Foundation ) - FE928/17-1 . Furthermore, the authors thank for financial support from The Research Council of Norway under the program Nano2021 to the project (Number 228854 ) “Thermoelectric materials: Nanostructuring for improving the energy efficiency of thermoelectric generators and heat-pumps” (THELMA).

PY - 2019/1/15

Y1 - 2019/1/15

N2 - 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.

AB - 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.

KW - CaCoO

KW - Energy conversion

KW - Oxides

KW - Power factor

KW - Thermoelectric generator

KW - Thermoelectricity

UR - http://www.scopus.com/inward/record.url?scp=85056472457&partnerID=8YFLogxK

U2 - 10.1016/j.jpowsour.2018.10.076

DO - 10.1016/j.jpowsour.2018.10.076

M3 - Article

AN - SCOPUS:85056472457

VL - 410-411

SP - 143

EP - 151

JO - Journal of Power Sources

JF - Journal of Power Sources

SN - 0378-7753

ER -