Condensed-Matter Physics & Materials Science Seminar

We have been relishing a lot of affluence thanks to energy. Fossil energy provides us fun to drive, warmth to escape from cold, brightness of illumination, etc. However consumption of the fossil fuel produces CO2. The amount of CO2 emission will increase with increasing consumption of fossil energy, gas, oil, and coal year by year. The average of total utilizing efficiency of the primary energy is as low as 30 %, with 70 % exhausted to the air as waste heat. It is clear that improved efficiencies of energy conversion systems could have a significant impact on energy consumption and carbon dioxide emission rate. Where a large sum of heat is localized, mechanical conversion systems can be used to generate electricity. However, most sources of waste heat are widely dispersed. Although technologies of storage and transport of such the dilute heat energy have been developed, most waste heat can't be used effectively. Electricity is a convenient form of energy that is easily transported, redirected, and stored, thus there are a number of advantages to the conversion of waste heat emitted from our living and industrial activities to electricity. Thermoelectric conversion is paid attention as the strongest candidate to generate electricity from dilute waste heat.
Oxide materials are considered to be promising ones because of their durability against high temperature, low cost for producing etc. The misfit CoO2 compounds show high thermoelectric efficiency at high temperature in air. Thermoelectric modules using p-type Ca3Co4O9, one of the CoO2 compounds and n-type CaMnO3 have been produced [1, 2]. The maximum power density against area of the substrate of the module reaches 4.3 kW/m2 at 973 K of the heat source temperature [3].
Portable power generation units composed of an oxide thermoelectric module. Water circulation and batteries for air cooling are unnecessary for thermoelectric conversion. The units can generate 2-5 W using heat energy with temperature of 300-8