Bandstructure and doping engineering for unprecedented power factors in half-Heusler thermoelectrics

Started

Other Cross-Cutting Technologies or Research

Basic and strategic applied research

PHYSICAL SCIENCES AND MATHEMATICS (Chemistry)
PHYSICAL SCIENCES AND MATHEMATICS (Metallurgy and Materials)

Not Cross-cutting

Dr J Bos
School of Engineering and Physical Sciences
Heriot-Watt University

Standard

EPSRC

01 October 2024

30 September 2027

36 months

£559,942

Materials sciences

Scotland

NC : Physical Sciences

Dr J Bos, School of Engineering and Physical Sciences, Heriot-Watt University

Project Contact, Technische Universität Wien, Austria
Project Contact, European Thermodynamics Ltd
Project Contact, University of Edinburgh
Project Contact, Lakes College West Cumbria

The UK is committed to achieving Net Zero by 2050. Waste heat is a huge cause of energy losses in domestic and industrial settings. Large scale thermoelectric recovery of waste heat into electricity can lead to significant reductions in CO2 emissions. In addition, there is a need to power the internet of things (IoT), which dictates the deployment of billions of interconnected sensor devices. Here thermoelectrics can provide free electricity by scavenging waste heat, eliminating the need for batteries or grid connectivity.However, despite the many advantages of the use of thermoelectricity in energy generation and scavenging, commercially it is still an inefficient and expensive technology which relies on scarce materials, mainly Tellurium compounds. New, abundant materials with ease of processing, which can enable large scale production in order to become competitive sources of electricity are needed. Amongst the many new materials investigated lately to increase performance and replace the prominent Bi2Te3 and PbTe for use in thermoelectric generators, half-Heuslers are leading contenders for mass production and commercialisation. They are stable, mechanically robust and are composed of abundant, inexpensive elements.However, a substantial improvement in their power output (i.e. improving W/£), which would largely exceed the power output of current thermoelectric devices is also needed. To radically improve the power output from thermoelectric materials, new approaches are required, beyond reducing the heat transport through them, which has been the key paradigm in the field.We propose an alternative, challenging and disruptive approach based on insights from advanced modelling of charge transport in half-Heusler materials. This shows that the power output, even of already studied materials, can be increased by 2-10-fold by improved materials growth, control of defect chemistry, doping and bandstructure engineering. This will reduce the £/W cost by up to an order of magnitude as the overall material compositions remain similar.This work is a paradigm shift in thermoelectric materials research away from the mainstream focus on nanostructuring and thermal conductivity reduction, to materials with huge electronic responses to a temperature difference. Success of this research will enable the application of Heusler alloys in large-scale waste-heat recovery (kW range energy harvesting) and/ or powering the internet of things (mW-W range of energy scavenging). The project team brings together leading UK expertise in Heusler materials synthesis and thermoelectric materials modelling and will work closely with Industrial and Academic partners to ensure success and translation into working technologies. The resulting developments in synthetic and computational methodologies will be highly relevant to other electronic and opto-electronic materials fields as well

16/10/24