go to top scroll for more

Projects


Projects: Projects for Investigator
Reference Number EP/J000620/1
Title High Performance Room Temperature Thermoelectric Oxide Materials by Controlling Nanostructure
Status Completed
Energy Categories Energy Efficiency(Other) 50%;
Other Power and Storage Technologies(Electric power conversion) 50%;
Research Types Basic and strategic applied research 100%
Science and Technology Fields PHYSICAL SCIENCES AND MATHEMATICS (Metallurgy and Materials) 100%
UKERC Cross Cutting Characterisation Not Cross-cutting 100%
Principal Investigator Prof R (Bob ) Freer
No email address given
Materials
University of Manchester
Award Type Standard
Funding Source EPSRC
Start Date 04 November 2011
End Date 03 November 2014
Duration 36 months
Total Grant Value £71,314
Industrial Sectors
Region North West
Programme NC : Physical Sciences
 
Investigators Principal Investigator Prof R (Bob ) Freer , Materials, University of Manchester (99.999%)
  Other Investigator Dr C Leach , Materials, University of Manchester (0.001%)
Web Site
Objectives
Abstract The Seebeck effect is a thermoelectric effect whereby a temperature gradient across a material is converted to a voltage, which can be exploited for power generation. The growing concern over fossil fuels and carbon emissions has led to detailed reviews of all aspects of energy generation and routes to reduce consumption. Thermoelectric (TE) technology, utilising the direct conversion of waste heat into electric power, has emerged as a serious contender, particular for automotive and transport related applications. Thermoelectric power modules employ multiple pairs of n-type and p-type TE materials. Traditional metallic TE materials (such as Bi2Te3 and PbTe), have been available for 50 years, but are based on toxic materials over which there is increasing environmental concern. Furthermore Te is a rare and increasingly expensive element. In the past decade there has been growing interest in oxide thermoelectrics because their structures and chemistry can be readily modified (to adjust properties), they are stable under a wide variety of operating conditions and have encouraging thermoelectric properties. Whilst oxides are candidates for high temperature applications, they also have considerable potential as "room temperature" thermoelectrics (ambient to 200C) for a range of domestic applications as well as elements in multi-stage high temperature thermoelectric generators.This investigation is concerned with understanding and improving the thermoelectric properties of Ti based oxide materials having mainly perovskite or spinel structures; targeted applications are for low temperatures (less than 200C). The conversion efficiency of thermoelectric materials is characterised by the figure of merit ZT (where T is temperature); ZT should be as high as possible. To maximise the Z value requires a high Seebeck coefficient (S), coupled with small thermal conductivity and high electrical conductivity. In principle electrical conductivity can be adjusted by changes in cation/anion composition. The greater challenge is to concurrently reduce thermal conductivity. However in oxide ceramics the lattice conductivity dominates thermal transport since phonons are the main carriers of heat. This affords the basis for a range of strategies for reducing heat conduction; essentially microstructural engineering at the nanoscale to increase phonon scattering. The nanostructuring approaches will be: Self Assembly Nanostructures (by spinoidal decomposition), nanoparticles precipitation, and nanonetworks where the grain boundary conductivity is controlled. Independently, thermoelectric enhancement can also be achieved by substitution of dopants to adjust the electrical conductivity. By systematically investigating the effect of different nanostructuring strategies we will be able to understand the mechanisms controlling thermal and electron transport in thermoelectric oxides.A key feature of the work is that we will adopt an integrated approach, combining the strengths of the UK and Japanese partners to address materials development, exploring nanostructuring strategies, investigating thermoelectric properties as a function of temperature, investigating the structures from the microstructure to the atom level, and preparing test modules from the best materials to evaluate their thermoelectric performance in power modules
Publications (none)
Final Report (none)
Added to Database 28/11/11