Copper-and-selenium-based thermoelectric material with high structural stability and preparation method thereof

Abstract

The invention relates to a copper-and-selenium-based thermoelectric material with high structural stability and a preparation method thereof, belonging to the field of thermoelectric material research. The chemical formula of the thermoelectric material is Li<y>Cu<1.85-x>Bi<x>Se, x is [0.02, 0.05], and y is [0.01, 0.03]. According to the invention, the Cu<1.85>Se-based thermoelectric material with a stable cubic phase structure is obtained only by changing the vacancy of copper (Cu); and on the above basis, the thermoelectric parameters of the material are adjusted by filling the copper (Cu) vacancy with lithium (Li) and doping bismuth (Bi), so the Li<y>Cu<1.85-x>Bi<x>Se thermoelectric material with greatly improved thermoelectric performance is obtained, the thermoelectric performance is at least improved by 3 times compared with the thermoelectric performance of a pure-phase Cu<1.85>Se-based thermoelectric material, and the structural transformation characteristics of a sample are not changed. The method has very important promotion significance in practical application for phase change inhibition of the copper-group sulfide-based thermoelectric material.

Description

technical field [0001] The invention belongs to the research field of thermoelectric materials, and in particular relates to a copper-selenium-based thermoelectric material with high structural stability and high thermoelectric performance and a preparation method thereof. Background technique [0002] Thermoelectric materials are functional materials based on the Seebeck effect and the Peltier effect to realize mutual conversion between thermal energy and electrical energy, and have long life, safety and reliability, environmental friendliness, no mechanical rotation, and effective use of low-density energy, etc. It has significant advantages in the fields of military, aerospace, electronics industry, industrial waste heat and automobile exhaust waste heat recovery and utilization. [0003] In recent years, Cu 2-δ X (X = S, Se or Te, δ represents Cu vacancy content) based thermoelectric materials have lower lattice thermal conductivity and higher thermoelectric performance...

AI Technical Summary

Problems solved by technology

However, the occurrence of phase transition means that the coefficient of thermal expansion of the material changes drastically, resulting in huge stress, which leads to cracks or even damage to the material or device; at the same time, the material will have a large latent heat at the phase transition point, and its thermoelectric properties cannot be accurately tested

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