TY - JOUR

T1 - Electrospun Ca3 Co4−xO9+δ nanofibers and nanoribbons: Microstructure and thermoelectric properties

AU - Kruppa, Katharina

AU - Maor, Itzhak I.

AU - Steinbach, Frank

AU - Beilin, Vadim

AU - Mann-Lahav, Meirav

AU - Wolf, Mario

AU - Grader, Gideon S.

AU - Feldhoff, Armin

N1 - Funding information: This work was financially supported by the Ministry of Science and Culture of Lower Saxony (MWK) in the frame of the Research Cooperation Lower Saxony?Israel. The work was supported by the Nancy & Stephan Grand Technion Energy Program (GTEP); GSG acknowledges the support of the Arturo Gruenbaum Chair in Materials Engineering. This research was supported by the Israeli Ministry of Energy as part of the scholarship's program for first to third degree students in the fields of energy.

PY - 2022/12/8

Y1 - 2022/12/8

N2 - AbstractOxide-based ceramics offer promising thermoelectric (TE) materials for recy-cling high-temperature waste heat, generated extensively from industrialsources. To further improve the functional performance of TE materials, theirpower factor should be increased. This can be achieved by nanostructuring andtexturing the oxide-based ceramics creating multiple interphases and nanopores,which simultaneously increase the electrical conductivity and the Seebeck coef-ficient. The aim of this work is to achieve this goal by compacting electrospunnanofibers of calcium cobaltite Ca3 Co 4−xO 9+δ, known to be a promising p-typeTE material with good functional properties and thermal stability up to 1200 Kin air. For this purpose, polycrystalline Ca3 Co 4−xO 9+δ nanofibers and nanorib-bons were fabricated by sol–gel electrospinning and calcination at intermediatetemperatures to obtain small primary particle sizes. Bulk ceramics were formedby sintering pressed compacts of calcined nanofibers during TE measurements.The bulk nanofiber sample pre-calcined at 973 K exhibited an improved Seebeckcoefficient of 176.5 S cm−1 and a power factor of 2.47 μW cm−1 K−2 similar to anelectrospun nanofiber-derived ceramic compacted by spark plasma sintering.

AB - AbstractOxide-based ceramics offer promising thermoelectric (TE) materials for recy-cling high-temperature waste heat, generated extensively from industrialsources. To further improve the functional performance of TE materials, theirpower factor should be increased. This can be achieved by nanostructuring andtexturing the oxide-based ceramics creating multiple interphases and nanopores,which simultaneously increase the electrical conductivity and the Seebeck coef-ficient. The aim of this work is to achieve this goal by compacting electrospunnanofibers of calcium cobaltite Ca3 Co 4−xO 9+δ, known to be a promising p-typeTE material with good functional properties and thermal stability up to 1200 Kin air. For this purpose, polycrystalline Ca3 Co 4−xO 9+δ nanofibers and nanorib-bons were fabricated by sol–gel electrospinning and calcination at intermediatetemperatures to obtain small primary particle sizes. Bulk ceramics were formedby sintering pressed compacts of calcined nanofibers during TE measurements.The bulk nanofiber sample pre-calcined at 973 K exhibited an improved Seebeckcoefficient of 176.5 S cm−1 and a power factor of 2.47 μW cm−1 K−2 similar to anelectrospun nanofiber-derived ceramic compacted by spark plasma sintering.

KW - electron microscopy

KW - electrospinning

KW - microstructure

KW - thermoelectric properties

UR - http://www.scopus.com/inward/record.url?scp=85140228703&partnerID=8YFLogxK

U2 - 10.1111/jace.18842

DO - 10.1111/jace.18842

M3 - Article

VL - 106

SP - 1170

EP - 1181

JO - Journal of the American Ceramic Society

JF - Journal of the American Ceramic Society

SN - 0002-7820

IS - 2

ER -