Research On CrN And WS₂ New Thermoelectric Materials

The environmental impact of global climate change due to the combustion of fossil fuels is becoming increasingly alarming.Thermoelectric materials are a kind of clean power resources that converts thermal gradients into usable electricity and is critical to solving future energy and environmental problems.Low conversion efficiency is the main problem of thermoelectric materials.In addition,many thermoelectric materials with high ZT have problems such as poor mechanical properties,the use of toxic elements,and high prices.Therefore,the search for new materials is of great significance for the development of thermoelectric materials.CrN is widely used as an abrasion-resistant coating material because of its good physical and chemical properties such as high hardness,wear resistance,and corrosion resistance.As an important industrial material,it is of great significance to find a simple method for preparing Cr N.As a potential thermoelectric material,the high-temperature thermoelectric properties of CrN have not been fully explored.WS₂ is often used as a lubricating material because of its low coefficient of friction,and its good ductility makes it a great application potential for thermoelectrically flexible wearable devices.However,the thermoelectric performance of WS₂ is too low to be further improved as a practical application.This article examines the potential value and problems of CrN and WS₂.?1?Explore new preparation methods for faster and simpler synthesis of CrN,and characterize the phases and components of the final products of different synthesis methods.The advantages and disadvantages of the different synthesis methods were analyzed.?2?The thermoelectric properties of CrN bulk samples ranging from 300 K to 848K were investigated.The electrical conductivity of the sample decreases with increasing temperature and exhibits a metal-like characteristic.The sample obtained the maximum power factor and ZT value at a temperature of 848 K,which were 3.68?W?cm^-1K^-2 and0.119,respectively.In addition,for the current situation where most thermoelectric materials only focus on the ZT of the material and neglect the mechanical properties,we studied the mechanical properties of CrN.The hardness of the CrN bulk sample was7.21 GPa.Thermogravimetric analysis shows that CrN remains stable at 900 K.The friction test showed a low friction coefficient?⁰.42?and good resistance of CrN.The good mechanical properties of CrN make it a promising prospect for thermoelectric applications in extreme environments.?3?WS₂/SiC and WS₂/CNT composite thermoelectric materials were synthesized by ultrasonic mixing.The effects of different composite ratios on the thermoelectric properties of WS₂ matrix materials were explored.The experimental results show that a certain proportion of SiC can effectively reduce the carrier concentration and mobility of the material,and thus reduce the Seebeck coefficient;compounding a certain amount of CNT can effectively reduce the thermal conductivity of WS₂ and increase the carrier concentration.Composite SiC and CNT can change the performance of a certain thermoelectric parameter to some extent,but the overall thermoelectric performance does not improve.