Engineering of Carbon-Oxide Composite Thermoelectric Nanomaterials
Lead Research Organisation:
University of Huddersfield
Department Name: Sch of Applied Sciences
Abstract
The growing concern over carbon emissions has led the development of alternative, greener and sustainable technologies including thermoelectrics (TE). TE devices are solid-state energy converters that transform thermal energy into electricity, applicable to power generation including transportation, nuclear, and manufacturing industries.
A limitation of traditional TE materials is the very narrow temperature range for maximum performance, as low as 50C for Bi2Te3, limited power output, relatively low efficiency, the cost and environmental concerns due to toxicity. If TE technology is to be used economically and reliably, the materials need to exhibit high TE efficiency over a wider temperature window. Oxides, e.g. titanate perovskites, are promising TE materials because of their flexible structure and high temperature stability; their current limitations are the modest efficiency. However, integration of oxide TEs and carbon nanotechnologies has the prospect of enhancing performance, via nanostructuring and band engineering at the nanoscale.
Our research vision is to enhance thermoelectric properties of oxides by integrating TE and carbon nanotechnologies, as either carbon (graphene) or carbide, into the oxide microstructure; this will generate carbon-oxide composites and extend the range of operating temperatures. However, the engineering of these composites can only be achieved if we characterize and control both the nanostructuring needed for reduced thermal conductivity, and the interface structures and compositions needed for increased electrical conductivity.
Our approach involves experiments and modelling to achieve the following objectives: (1) to fabricate thermoelectrics carbon-oxide composites based on SrTiO3, TiO2, with a range of nanostructures to determine the factors controlling electric and thermal transport; (2) to identify the interactions between oxides and carbon that lead to enhanced performance; (3) to produce atomistic models of target microstructures, and to characterize their stability, topology, composition and electronic structure.
This proposal is part of a collaboration with the University of Manchester and Bath. It is novel and timely because exploits novel material processing strategies using a multidisciplinary approach (modelling/experiments) to study emerging technologies for cheap and sustainable energy generation. The UK needs to be at the forefront of this field as there are indeed major programmes in TE in Japan, USA, and Europe.
The work programme covers (1) target materials: SrTiO3, TiO2 ceramics, (2) materials processing, (3) microstructural control of oxide-graphene (i.e. La/SrTiO3 with graphene) and oxide-carbide (TiC1-xOx/TiOy) composites, (4) general characterization with routine XRD and SEM, (5) measurements of thermoelectric parameters, (6) characterization of the role and generation of interfaces and nanostructures.
A limitation of traditional TE materials is the very narrow temperature range for maximum performance, as low as 50C for Bi2Te3, limited power output, relatively low efficiency, the cost and environmental concerns due to toxicity. If TE technology is to be used economically and reliably, the materials need to exhibit high TE efficiency over a wider temperature window. Oxides, e.g. titanate perovskites, are promising TE materials because of their flexible structure and high temperature stability; their current limitations are the modest efficiency. However, integration of oxide TEs and carbon nanotechnologies has the prospect of enhancing performance, via nanostructuring and band engineering at the nanoscale.
Our research vision is to enhance thermoelectric properties of oxides by integrating TE and carbon nanotechnologies, as either carbon (graphene) or carbide, into the oxide microstructure; this will generate carbon-oxide composites and extend the range of operating temperatures. However, the engineering of these composites can only be achieved if we characterize and control both the nanostructuring needed for reduced thermal conductivity, and the interface structures and compositions needed for increased electrical conductivity.
Our approach involves experiments and modelling to achieve the following objectives: (1) to fabricate thermoelectrics carbon-oxide composites based on SrTiO3, TiO2, with a range of nanostructures to determine the factors controlling electric and thermal transport; (2) to identify the interactions between oxides and carbon that lead to enhanced performance; (3) to produce atomistic models of target microstructures, and to characterize their stability, topology, composition and electronic structure.
This proposal is part of a collaboration with the University of Manchester and Bath. It is novel and timely because exploits novel material processing strategies using a multidisciplinary approach (modelling/experiments) to study emerging technologies for cheap and sustainable energy generation. The UK needs to be at the forefront of this field as there are indeed major programmes in TE in Japan, USA, and Europe.
The work programme covers (1) target materials: SrTiO3, TiO2 ceramics, (2) materials processing, (3) microstructural control of oxide-graphene (i.e. La/SrTiO3 with graphene) and oxide-carbide (TiC1-xOx/TiOy) composites, (4) general characterization with routine XRD and SEM, (5) measurements of thermoelectric parameters, (6) characterization of the role and generation of interfaces and nanostructures.
Organisations
Studentship Projects
| Project Reference | Relationship | Related To | Start | End | Student Name |
|---|---|---|---|---|---|
| EP/R513234/1 | 01/10/2018 | 30/09/2023 | |||
| 2282312 | Studentship | EP/R513234/1 | 01/10/2019 | 30/09/2022 | Nathan Wood |
| Description | The understanding of the material properties appertaining to SrTiO3 both as an individual material and within the context of a composite material is fundamental across a wide array of applications, whether as supercapacitors, thermoelectric materials or other electronic applications. Within this study, we employ both classical modelling for the understanding of SrTiO3 as an individual material, whilst employing the latest settings for Density Functional Theory (DFT) calculations for SrTiO3 composite materials. Within the context of SrTiO3 as an individual material, the defect chemistry (both intrinsic and extrinsic) is explored and compared to previous findings, whilst for the first time the influence of defects in various Ruddlesden-Popper (RP) phases is explored, along with the development of electronic compensation scheme which relies on experimentally derived bandgaps and formation energies rather than free-ion interatomic energies. Whilst as a composite material, the interaction of SrTiO3 surfaces with respect to both graphene and polyaniline (in its various oxidation states) are characterised. The electronic density of states is then calculated and used to estimate the thermoelectric properties of such composites, whereas the thermal conductivity is estimated using calculations based on classical techniques. |
| Exploitation Route | 1) A computational or definitive experimental study on the influence of Ruddlesden-Popper (RP) phases on SrTiO3 defect chemistry has not been done previously. This will allow other researchers to build upon this work, whilst also providing a deeper understanding of RP phase defect chemistry 2) The electronic compensation scheme which relies on experimentally derived bandgaps and formation energies rather than free-ion interatomic energies can be applied to other classical model research 3) The understanding of the electronic and thermal effects of compositing SrTiO3 with polyaniline and polyaniline +Graphene is not well understood. The knowledge gained from this will increase the understanding and benefit further research. 4) The development of a SrTiO3-polyaniline potential model will have applications for other researchers. |
| Sectors | Electronics,Energy,Environment |
| Description | Oral and Poster Presentations at Conferences |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Industry/Business |
| Results and Impact | Oral and Poster presentations have be performed at a number of national level conferences. Poster presentations were excellent for discussing the work with other academics, whilst also providing a good platform for networking at a national level. Whilst talks at the ACS offered a chance to share research with an international audience, both academically and industrial/business. This presented excellent networking opportunities. Posters: 1) Modelling Strontium Titanate Defect Chemistry, 16 Dec 2019, 39th Christmas Meeting of the Royal Society of Chemistry Solid State Chemistry Group 2) Defect Chemistry in Strontium Titanate: A modeling approach, 10 Jan 2020, New Horizons in Materials Modelling 2020 3) Partial-charge rigid-ion potential model for describing the defect chemistry of SrTiO3, 5 Apr 2021, ACS Spring 2021 4) Engineering the polyaniline:SrTiO3 interface: A density functional theory study, 15 Jul 2021, CCP5 Summer School 2021 5) A rigid-ion model for mixing SrTiO3 with PANI, 7 Sep 2022, CCP5 Annual General Meeting 2022, 42nd edition Talks: 1) Engineering the polyaniline:SrTiO3 interface: A density functional theory study, 5 Apr 2021, ACS Spring 2021 2) The thermoelectric properties of Polyaniline-SrTiO3 composites, 6 Jul 2022, UK's HEC Materials Chemistry Consortium: 4th Conference: Materials Modelling using Tera and Petascale Computing 3) Composites made of Polyaniline and SrTiO3: Thermoelectric Abilities, 7 Sep 2022, CCP5 Annual General Meeting 2022, 42nd edition |
| Year(s) Of Engagement Activity | 2019,2020,2021 |