Low Temperature Sintering Of Cu_2-xS Based Thermoelectric Materials

The economy is developing,and It's speeding up.Human beings need more energy.Now more problems appear,people are lack of A sober understanding.Traditional energy is overused,the utilization rate of materials is low,a lot of waste heat is released,and the quality of our natural environment has become an important issue.Countries do their best to solve the questions.The current global focus is on the development and application of new energy.Thermoelectric material is a kind of functional material,which is clean and good for environment.It's quite practical.It can realize the mutual conversion of electric energy and hot spot.The thermoelectric device made according to the basic principle has a great application prospect.Among the new thermoelectric materials studied at present,Cu2-xS system gets more attention.There are several reasons.1.The cost of raw materials is low and there is no toxicity;2.The mobility of Cu+is high;3.As the material is at high temperature,It's conductivity is low and ZT is large;4.Cu2-x S is an important conductor,both because of its high conductivity.In this paper,Cu2-x S is taken as the research object to study whether mechanical alloy method affects the thermoelectric properties of the material.The following is the research content:1.First of all,prepare Cu2-xAlxS(x=0,0.01,0.015,0.02)by mechanical alloy method.High purity copper powder(?99.9%),sulfur powder(?99.9%)and aluminum powder(?99.9%)are doped.Then the material is pressed at low temperature and nodulized.Finally,Check its performance.The results show that doping Al element can improve the conductivity of Cu2S,and compare to Cu2S,the performance of Cu2-xAlxS(x=0,0.01,0.015,0.02)is better The higher the temperature,the larger the value of ZT.2.First of all,prepare Cu2-xFexS(x=0,0.01,0.015,0.02)by mechanical alloy method.High purity copper powder(?99.9%),sulfur powder(?99.9%)and iron powder(?99.9%)are doped.Then the material is pressed at low temperature and nodulized.Finally,Check its performance.This study indicates that when the temperature is rising higher,the conductivity of all samples of doped Fe element shows a trend of first decreasing and then increasing,The trend of thermal conductivity is declining,and compare to Cu2S,Its value is lower.The ZT value increases in varying degrees.All the thermoelectric properties are basically better than pure sample,Doping is a good way of optimizing thermoelectric properties.Cu1.985Fe0.015S has the highest ZT value at 823K,which is 2.15,The results show that cold pressing sintering has great potential and great application prospect in the field of thermoelectric materials.3.First of all,prepare Cu2-xSnxS(x=0,0.01,0.015,0.02)by mechanical alloy method.High purity copper powder(?99.9%),sulfur powder(?99.9%)and tin powder(?99.9%)are doped.Then the material is pressed at low temperature and nodulized.Finally,Check its performance.The results show that the electrical conductivity of the samples doped with Sn is decreasing as a whole.The higher the temperature,the thermal conductivity of Cu1.985Sn0.015S and Cu1.98Sn0.02S increased to a certain extent,and the ZT value increased gradually.The thermoelectric properties of the doped samples are obviously better than that of the pure samples.At 823K,Cu1.99Sn0.01 S has the highest ZT value,which is 0.799.4.First of all,prepare Cu2-xTexS(x=0,0.01,0.015,0.02)by mechanical alloy method.High purity copper powder(?99.9%),sulfur powder(?99.9%)and tellurium powder(?99.9%)are doped.Then the material is pressed at low temperature and nodulized.Finally,Check its performance.The results show that the conductivity of Te doped sample decreases.the thermal conductivity of Cu1.98Te0.02S is the best,and the ZT value is 1.33.