Exploring the strategies towards enhancing the thermoelectric performance in oxide materials

Abstract

Oxide materials are currently considered a promising alternative to traditional thermoelectrics. Moderate charge carrier mobility stemming from strong covalent and ionic bonding, combined with relatively high thermal conductivity, represent known disadvantages of these materials for thermoelectric applications. However, oxides offer a possibility to operate at high temperatures, resulting in a higher Carnot efficiency. In addition, their known structural and microstructural versatility can open new horizons for thermoelectric applications. This work reviews some representative cases of engineering the composition and microstructure of a series of selected oxides towards high thermoelectric performance. The selected approaches will include laser processing, in situ formed composites, defects tailoring and aluminothermy-boosted sintering, also taking into account the unique redox-tuning capabilities of oxides. Representative examples will include ceramic materials based on SrTiO3, ZnO, CaMnO3 and Ca3Co4O9