One Step Closer to Powering the Future: Improving the Efficiency of Thermoelectric Materials
In the United states, nearly 70 percent of the energy produced goes unused and is ultimately rejected to the environment as waste heat. Capturing and reusing that waste heat can be achieved by using thermoelectricity, the phenomena by which thermal energy is directly converted into electrical energy without any moving parts or working fluids.
“Thermoelectric materials possess tremendous potential to recover waste heat and harvest energy from thermal energy sources such as body heat, solar heat and fire,” says Emrah Celik, an assistant professor in the College of Engineering’s Department of Mechanical and Aerospace Engineering. “Since thermoelectric systems can convert temperature differences into electricity without any moving parts or fluids, they require minimal maintenance compared to traditional energy converters.”
Despite their unique advantages, these systems suffer from low efficiency relative to other electric generators. Efficient thermoelectric materials need to be good conductors of electricity, but poor conductors of thermal energy. This is a fundamental problem, because in traditional materials, both quantities – thermal and electrical conductivity – are strongly dependent on each other; increasing one causes an increase in the other.
However, nanoengineered materials provide a unique way of addressing this issue. By fine-tuning the thermal and electrical properties of a material, scientists can selectively reduce thermal conductivity and/or enhance electrical conductivity. Celik is working with Roger LeBlanc, a professor in the College of Arts and Sciences’ Department of Chemistry, to manipulate the molecular arrangements of thermoelectric materials to enhance the electrical conductivity of thermoelectric materials.
The collaborative research project will investigate and quantify the effects of adding impurities to thermoelectric materials in the form of carbon quantum dots (CDs) – tiny carbon particles less than ten millionths of a millimeter in size – to modify the material’s thermoelectric properties and efficiency, a process called ‘doping’.
“This is the first study that will explore the design processes of CD-doped thermoelectric materials focusing not only on the design of advanced materials, but also on the physical phenomena behind the effects of CD doping as well as the novel chemical synthesis of CDs,” explains Celik.
The project will benefit from LeBlanc’s extensive experience on synthesis, characterization, and application of CDs, as well as Celik’s expertise on thermoelectric materials and their novel fabrication using 3D printing technologies.
“This research has significant potential for the design of novel nanocomposite materials with superior thermoelectrical properties,” says Celik. “Successful manufacturing of these materials will lead to unique applications in energy harvesting and benefit the United States economy as and technological advancement.”
The research project, officially titled “Quantum confinement effects in carbon-quantum-dot integrated thermoelectric materials,” is one of seven awards funded by the College of Engineering and the College of Arts and Sciences that focus on the topics related to the Frost Institute of Chemistry and Molecular Science (FICMS), the first of the Frost Institutes for Science and Engineering that will be housed in the new Phillip and Patricia Frost Science and Engineering Building.