Segmentation of low-cost high efficiency oxide-based thermoelectric materials

Thermoelectric (TE) oxide materials have attracted great interest in advanced renewable energy research owing to the fact that they consist of abundant elements, can be manufactured by low-cost processing, sustain high temperatures, be robust and provide long lifetime. However, the low conversion efficiency of TE oxides has been a major drawback limiting these materials to broaden applications. In this work, theoretical calculations are used to predict how segmentation of oxide and semimetal materials, utilizing the benefits of both types of materials, can provide high efficiency, high temperature oxide-based segmented legs. The materials for segmentation are selected by their compatibility factors and their conversion efficiency versus material cost, i.e., efficiency ratio. Numerical modelling results showed that conversion efficiency could reach values of more than 10% for unicouples using segmented legs based p-type Ca3Co4O9 and n-type ZnO oxides excluding electrical and thermal losses. It is found that the maximum efficiency of segmented unicouple could be linearly decreased with increasing the interfacial contact resistance. The obtained results provide useful tool for designing a low-cost and high efficiency thermoelectric modules based-oxide materials.