Preparation And Measurement Technology Of Bi-Ca-Co-O/Ca₃Co₄O₉Composite Thermoelectric Ceramic

Thermoelectric generator can convert heat into electricity directly by using the Seebeckeffect of thermoelectric materials. Because of its advantages such as no pollution, long servicelife and high reliability, thermoelectric generator has a broad application prospect in the wasteheat recovery and geothermal development, it is also very important for the development ofnational economy.Traditionally, the thermoelectric materials and thermoelectric devices will carry outindependently; this research mode is not conducive for the performance optimization ofthermoelectric materials in practical application, especially in the waste heat recovery fieldwhere the thermal environment is complex and variable. To achieve the optimization ofthermoelectric materials and devices under working condition, this paper makes a preliminarystudy from thermodynamic theory and thermoelectric testing theory under working condition.In theory, this paper tries to character the thermoelectric performance of materials, suchas the thermoelectric figure of merit, power factor and so on, by using a simplified theoreticalmodel of thermoelectric carries. Also, this paper provides a realization design theory ofthermoelectric materials and devices under working condition.In measurement, this paper set up a test system of thermoelectric materials and devicesand achieved the integral testing of them with the thermoelectric performance analysis theoryunder working condition. Then a fast-measurement method of Seebeck coefficient and itsrelated algorithms have been provided.To improve the performance of thermoelectric material Ca₃Co₄O₉in practical application,we explored the further optimization of the Ca-Co-O system materials from the view ofdevice research, then Bi-Ca-Co-O/Ca₃Co₄O₉composite thermoelectric materials has beenprepared. This idea can be referenced for the preparing of other composite thermoelectricceramics.