Preparation And Doping Properties Of Thermoelectric Materials Of Ca₃Co₄O₉

With the decrease of energy sources that can be exploited and the severity of the environment pollutions caused by coal, oil and natural gas, it has become urgent that develops new clean energy sources. In spite of the low transition efficiency, the thermoelectric transition equipments have a lot of characteristics such as no moving parts, pollution and noise, long life span and safety, which stirs people to research them with great enthuseiasm. As the key part of the thermoelectric generation equipment, thermoelectric material becomes the important research object. In my work, thermoelectric material of Ca3_Co₄O₉ was synthesized and its thermoelectric properties was studied by different dopants.In the dissertation, the sol-gel method was used to synthesize the pure Ca₃Co₄O₉ and the Ca₃Co₄O₉ with doping different ions (Na⁺,Ag⁺,La²⁺). TG-DTA, IR, XRD, SEM and thermoelectric property test used to research the structure, microscopic appearance and thermoelectric properties of Ca₃Co₄O₉. Doping different ions which effect on the structure of Ca₃Co₄O₉ was also studied. The experimental results show that the sol-gel method is better than others. Doping each kind of different metallic ion according to the different allocated proportion (Na⁺,Ag⁺,La²⁺), optimized the sample current carrier density, enable the tricity performance to have the varying degree change.