TY - CONF A1 - Bresch, Sophie A1 - Mieller, Björn A1 - Stargardt, Patrick A1 - Töpfer, Jörg A1 - Moos, Ralf A1 - Rabe, Torsten T1 - Development of textured multilayer thermoelectric generators based on calcium cobaltite N2 - Thermoelectric generators can be used as energy harvesters for sensor applications. Multilayer thermoelectric generators (ML-TEGs) are a promising alternative to conventional π-type generators due to their high filling factor, high capability of automated production and the texturing potential during the production process. Calcium cobaltite is a promising thermoelectric oxide (p-type) with highly anisotropic properties. The following study shows the development of a textured unileg ML-TEG using ceramic multilayer technology. Tape-casting and pressure assisted sintering are applied to fabricate textured calcium cobaltite. Compared to conventional sintering, pressure assisted sintering increases the strength by the factor 10. Thermoelectric properties can be tuned either towards maximum power factor or towards maximum figure of merit depending on the pressure level. As electrical insulation material, a screen-printable glass-ceramic with high resistivity and adapted coefficient of thermal expansion is developed. From various commercial pastes a metallization with low contact resistance is chosen. The unileg ML-TEG is co-fired in one single step. The demonstrators reach 80% of the simulated output power and the power output is highly reproducible between the different demonstrators (99%). These results provide the first proof-of-concept for fabricating co-fired multilayer generators based on textured calcium cobaltite with high power factor, high density, and high strength. T2 - Virtual Conference on Thermoelectrics 2021 (VCT) CY - Online meeting DA - 20.07.2021 KW - Thermoelectrics KW - Multilayertechnik KW - Screen printing PY - 2021 AN - OPUS4-52993 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bresch, Sophie T1 - Entwicklung thermoelektrischer Multilayergeneratoren auf der Basis von Calciumcobaltit N2 - Thermoelectric generators can be used as energy harvesters for sensor applications. Multilayer thermoelectric generators (ML-TEGs) are a promising alternative to conventional π-type generators due to their high filling factor, high capability of automated production and the texturing potential during the production process. Calcium cobaltite is a promising thermoelectric oxide (p-type) with highly anisotropic properties. The following study shows the development of a textured unileg ML-TEG using ceramic multilayer technology. Tape-casting and pressure assisted sintering are applied to fabricate textured calcium cobaltite. Compared to conventional sintering, pressure assisted sintering increases the strength by the factor 10. Thermoelectric properties can be tuned either towards maximum power factor or towards maximum figure of merit depending on the pressure level. As electrical insulation material, a screen-printable glass-ceramic with high resistivity and adapted coefficient of thermal expansion is developed. From various commercial pastes a metallization with low contact resistance is chosen. The unileg ML-TEG is co-fired in one single step. The demonstrators reach 80% of the simulated output power and the power output is highly reproducible between the different demonstrators (99%). These results provide the first proof-of-concept for fabricating co-fired multilayer generators based on textured calcium cobaltite with high power factor, high density, and high strength. N2 - Thermoelektrische Generatoren können zum „Energy harvesting“ für den autarken Betrieb von bspw. Sensoren eingesetzt werden. Eine interessante Alternative zu den herkömmlichen π-Typ Generatoren sind auf Grund der höheren Leistungsdichte und der guten Automatisierbarkeit thermoelektrische Multilayergeneratoren. Calciumcobaltit ist ein vielsprechendes oxidisches Thermoelektrika (p-Typ) mit stark anisotropen Eigenschaften. Die hier vorgestellte Studie zeigt die Entwicklung von texturierten Unileg-Multilayer-Generatoren mittels keramischer Multilayertechnologie. Calciumcobaltit wird durch Foliengießen und druckunterstützte Sinterung texturiert. Im Vergleich zur konventionellen Sinterung verbessert sich die Festigkeit um den Faktor 10. Die thermoelektrischen Eigenschaften können je nach verwendetem Druckniveau hinsichtlich maximalem Power Factor oder hinsichtlich maximalem Gütefaktor optimiert werden. Ein Glaskeramikkomposit wird als Isolationsmaterial mit hohem Volumenwiderstand und angepasstem Wärmeausdehnungskoeffizienten entwickelt. Der Unileg-Multilayer-Generator wird in einem Schritt co-gesintert. Die hergestellten Demonstratoren erreichen 80% der simulierten Output-Leistung. Diese Ergebnisse stellen den ersten Machbarkeitsnachweis für die Herstellung von co-gesinterten Multilayer-Generatoren aus texturiertem Calciumcobaltit mit hohem Power Factor und hoher Festigkeit dar. T2 - Seminar des Lehrstuhls für Funktionsmaterialien, Universität Bayreuth CY - Online meeting DA - 18.06.2021 KW - Thermoelektrischer Generator KW - Multilayertechnik KW - Energy harvesting PY - 2021 AN - OPUS4-52834 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -