Method for improving thermoelectric properties of bismuth sulfide polycrystal

Abstract

The invention discloses a method for improving the thermoelectric performance of bismuth sulfide polycrystal, which belongs to the technical field of energy materials. It is characterized in that: bismuth sulfide nano powder prepared by mechanical alloying method is mixed with (001) oriented single crystal bismuth sulfide nano rod powder synthesized by hydrothermal method, ultrasonically dispersed in absolute ethanol for 10 to 200 minutes, baked Grind by hand in an agate mortar and pestle for 10-100 minutes after drying. The ground powder is placed in a graphite mold, sintered at 300-500°C by a spark plasma sintering process, and held for 0-30 minutes to prepare a bismuth sulfide polycrystalline block. Spark plasma sintering has a fast heating speed, which inhibits the growth and fusion of grains, keeps the single crystal nanorod structure in the polycrystalline bulk, forms a fast channel for carrier migration, and greatly improves the electrical transport performance and Thermoelectric properties, the method has the advantages of simple required equipment, easy operation, low cost, remarkable effect and the like.

Description

technical field [0001] The invention belongs to the technical field of energy materials, in particular to a method for improving the thermoelectric properties of bismuth sulfide polycrystals, and involves mechanical alloying, hydrothermal synthesis and discharge plasma sintering technologies. Background technique [0002] With the continuous development of social economy, environmental and energy issues are paid more and more attention by human beings. Thermoelectric materials can directly realize the mutual conversion of heat energy and electric energy. Thermoelectric devices are pollution-free, zero-emission, light in structure, small in size and long in life, and are increasingly attracting people's attention. Thermoelectric modules with thermoelectric devices as core components have broad application prospects in semiconductor refrigeration and thermoelectric batteries. In the competition with conventional refrigeration methods and traditional power sources, the key to ...

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Problems solved by technology

Therefore, for excellent polycrystalline thermoelectric materials, high electrical conductivity and low thermal conductivity are required, and there is a contradiction in the optimization of grain size. It is impossible to solve the problem of obtaining high electrical conductivity and low thermal conductivity by adjusting the grain size. rate of contradiction

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