Some Thermoelectric Phenomena in Copper Chalcogenides Replaced by Lithium and Sodium Alkaline Metals

Abstract

This review presents thermoelectric phenomena in copper chalcogenides substituted with sodium and lithium alkali metals. The results for other modern thermoelectric materials are presented for comparison. The results of the study of the crystal structure and phase transitions in the ternary systems Na-Cu-S and Li-Cu-S are presented. The main synthesis methods of nanocrystalline copper chalcogenides and its alloys are presented, as well as electrical, thermodynamic, thermal, and thermoelectric properties and practical application. The features of mixed electron–ionic conductors are discussed. In particular, in semiconductor superionic copper chalcogenides, the presence of a “liquid-like phase” inside a “solid” lattice interferes with the normal propagation of phonons; therefore, superionic copper chalcogenides have low lattice thermal conductivity, and this is a favorable factor for the formation of high thermoelectric efficiency in them.

Thermal properties of nanocrystalline copper sulfides KxCu1.85S (0 < x < 0.05)

“…The low thermal conductivity of these systems is provided by the suppression of phonon transfer in a "liquid-like" cationic substrate that does not suppress electron transfer. Thermal conductivity in thermoelectric materials is provided by electrons and holes that transfer heat and / or by phonons propagating along the crystal lattice [16].…”

Effect of Copper Selenide Modification on the Conductivity of PA6, PA66, PAN, and PES Fibers

“…As an important semiconductor, copper selenide (Cu x Se) with nanostructure has potential applications in various fields, such as optical filters, highly efficient solar cells, superionic conductors, electro-optical devices, photothermal conversion, microwave shielding coatings, etc. [15,16].…”

Electrochemical properties of Na3Fe2(PO4)3 cathode materials produced by various synthesis methods and evaluation of the possibility of their use in sodium-ion batteries

“…A porous cathode material based on Na 3 Fe 2 (PO 4 ) 3 obtained by the sol-gel method is capable of generating an initial specific discharge capacity of up to 92.5 mAh g −1 in SIB [11]. In [11,12], Na 3 Fe 2 (PO 4 ) 3 is considered as a promising anode material for aqueous SIB. Therefore, further investigation of the electrochemical properties of cathodes based on sodium-iron orthophosphate is highly relevant.…”