Composite strontium titanate thermoelectric material and preparation method thereof

Abstract

The invention discloses a composite strontium titanate thermoelectric material. The composite strontium titanate thermoelectric material is prepared from niobium-doped strontium titanate powder and potassium titanate nanowire powder. The invention further discloses a preparation method of the composite strontium titanate thermoelectric material. The preparation method comprises the following steps: uniformly mixing the potassium titanate nanowire powder in a certain ratio into the niobium-doped strontium titanate powder to obtain a mixture; performing 15-25MPa cold isostatic pressing on the mixture to prepare a blank; calcining the blank for 2-4 hours in an argon atmosphere at 1400-1600 DEG C. The nano-composite thermoelectric material is prepared by compounding a nano titanium potassium additive with ultralow thermal conductivity and strontium titanate, and a large number of phonon scattering interfaces are effectively introduced, so that the thermal conductivity of the prepared thermoelectric material is significantly reduced and the electrical conductivity thereof is not significantly reduced, and thus the thermoelectric figure of merit is significantly improved.

Description

technical field [0001] The invention relates to the field of thermoelectric materials, in particular to a composite strontium titanate thermoelectric material and a preparation method thereof. Background technique [0002] A thermoelectric material is a material that can convert thermal energy to electrical energy (static energy conversion) in a solid state. Thermoelectric materials can be made into light-weight and small-sized micro-semiconductor refrigerators, which can solve refrigeration problems in high-tech fields such as computer technology, aerospace technology, superconducting technology, and microelectronics technology. Thermoelectric materials can also use waste heat or temperature difference to generate electricity, and the steel and chemical industries that release a lot of waste heat are important areas for their future applications. Devices made of thermoelectric materials have many advantages: no moving parts, simple structure, high reliability, long life, e...

AI Technical Summary

Problems solved by technology

So far, the relatively mature thermoelectric materials are still BiTe, Ag-Pb-Sb-Te, SiGe and other metal elements that contain Te and Ge, which have a load on the environment and are very rare metal elements, which is very unfavorable for the large-scale application of thermoelectric materials. Therefore, The development of low-cost and environmentally friendly oxide thermoelectric materials is a new hotspot in the research of thermoelectric materials

[0004] Thermoelectric materials are mainly evaluated by the thermoelectric figure of merit (ZT). At present, the best performance of P-type oxide thermoelectric materials is the sodium cobaltate system, and the ZT value is close to 1, which basically meets the requirements for use, while the performance of N-type oxide thermoelectric materials is the best. The best is the strontium titanate system, but the highest ZT value is about 0.29, which is far from the application

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