Enhanced Thermoelectric Performance of Na<sub>0.55</sub>CoO<sub>2</sub> Ceramics Doped by Transition and Heavy Metal Oxides
Natalie S. Krasutskaya,
Andrei I. Klyndyuk,
Lyudmila E. Evseeva,
Nikolai N. Gundilovich,
Ekaterina A. Chizhova,
Andrei V. Paspelau
Affiliations
Natalie S. Krasutskaya
Department of Physical, Colloid and Analytical Chemistry, Organic Substances Technology Faculty, Belarusian State Technological University, Sverdlova St. 13a, 220006 Minsk, Belarus
Andrei I. Klyndyuk
Department of Physical, Colloid and Analytical Chemistry, Organic Substances Technology Faculty, Belarusian State Technological University, Sverdlova St. 13a, 220006 Minsk, Belarus
Lyudmila E. Evseeva
Thermophysical Measurement Lab, A.V. Luikov Heat and Mass Transfer Institute of the National Academy of Sciences of Belarus, Brovki St. 15, 220072 Minsk, Belarus
Nikolai N. Gundilovich
Department of Glass and Ceramics Technology, Chemical Technology and Engineering Faculty, Belarusian State Technological University, Sverdlova St. 13a, 220006 Minsk, Belarus
Ekaterina A. Chizhova
Department of Physical, Colloid and Analytical Chemistry, Organic Substances Technology Faculty, Belarusian State Technological University, Sverdlova St. 13a, 220006 Minsk, Belarus
Andrei V. Paspelau
Physical and Chemical Investigations Methods Center, Belarusian State Technological University, Sverdlova St. 13a, 220006 Minsk, Belarus
Using the solid-state reactions method Na0.55(Co,M)O2 (M = Cr, Ni, Zn, W, and Bi) ceramics were prepared and their crystal structure, microstructure, electrophysical, thermophysical, and thermoelectric properties were studied. Doping of Na0.55CoO2 by transition or heavy metal oxides led to the increase in the grain size of ceramics, a decrease in electrical resistivity and thermal diffusivity values, and a sharp increase in the Seebeck coefficient, which resulted in essential enhancement of their thermoelectric properties. The largest power factor (1.04 mW/(m·K2) at 1073 K) and figure of merit (0.702 at 1073 K) among the studied samples possessed the Na0.55Co0.9Bi0.1O2 compound, which also demonstrated the highest values of the Seebeck coefficient (666 μV/K at 1073 K). The obtained results show that the doping of layered sodium cobaltite by different metal oxides allows for improving its stability, microstructure, and functional properties, which proves the effectiveness of the doping strategy for developing new thermoelectric oxides with enhanced thermoelectric performance.
