Thermoelectric oxides are considered as perspective materials for energy conversion due to their high thermal and chemical stability, low cost and environmental compatibility in comparison with the conventional semiconductors based on bismuth and tellurium [1]. Herein we report firstly the thermoelectric properties of composites between perovskite and layered oxides. The proof-of-concept studies conducted on LaCo0.8Ni0.1Fe0.1O3 perovskite and layered Ca3Co4O9 oxides demonstrate the improved thermoelectric properties of composites through the enhancing the boundaries phonon scattering without affecting the electronic transport. The oxide composites are formed by mechanical milling followed by annealing at 900 oC. This procedure allows to achieve a good contact between particles without changing the structure and composition of two components. The thermoelectric efficiency of the composites is determined by the dimensionless figure of merit (ZT) calculated from the independently measured Seebeck coefficient, electrical resistivity (Table 1), and thermal conductivity. The observed changes in the electrical resistivity of the composites are explained by the particle size effects and the contact between particles. It is found that the thermoelectric activity of the composites is higher than that of the individual components.

Thermoelectric composites between cobalt-based perovskite and layered oxides

ACS Spring Meeting 2021

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