Transformative Recovery of Low-Grade Waste Heat using Ionic Thermoelectrics
Lead Research Organisation:
Heriot-Watt University
Department Name: Sch of Engineering and Physical Science
Abstract
Electronic thermoelectrics use semiconductors to convert waste heat into electricity. This is an established energy generation technology, for example, used by NASA to power the Mars Rovers. However, it is not very suitable for low-grade waste heat recovery due to poor power generation from small temperature differences.
Ionic conductors generate much larger thermal voltages and are better suited to near room temperature operation. However, they cannot be used in the same mode of operation as this would require a continuous flow of ions. The innovative solution proposed is to couple the ionic conductor with an energy storage system that converts the ionic potential to an electronic one.
This proposal will investigate novel ionic thermoelectric power generation devices consisting of an ionic conductor sandwiched between two energy stores, including supercapacitors and insertion materials. This is a novel approach targeted at recovery of low-grade waste heat, increasing the sustainability of industrial processes and reducing carbon emissions.
Ionic conductors generate much larger thermal voltages and are better suited to near room temperature operation. However, they cannot be used in the same mode of operation as this would require a continuous flow of ions. The innovative solution proposed is to couple the ionic conductor with an energy storage system that converts the ionic potential to an electronic one.
This proposal will investigate novel ionic thermoelectric power generation devices consisting of an ionic conductor sandwiched between two energy stores, including supercapacitors and insertion materials. This is a novel approach targeted at recovery of low-grade waste heat, increasing the sustainability of industrial processes and reducing carbon emissions.
Publications
Downie R
(2023)
Thermoelectric properties and Kondo transition in the pseudo-gap metals TiNiSi and TiNiGe
in Zeitschrift für anorganische und allgemeine Chemie
Quinn RJ
(2024)
Alloying and Doping Control in the Layered Metal Phosphide Thermoelectric CaCuP.
in ACS applied electronic materials
Related Projects
| Project Reference | Relationship | Related To | Start | End | Award Value |
|---|---|---|---|---|---|
| EP/W037300/1 | 30/09/2022 | 29/04/2023 | £252,244 | ||
| EP/W037300/2 | Transfer | EP/W037300/1 | 30/04/2023 | 30/03/2025 | £161,465 |
| Description | The aim of the project was to utilise the Seebeck voltage generated by ionic conductors in a temperature gradient to harvest waste heat. Successes include the preparation and characterization of doped NASICON and Beta-alumina materials with state-of-the-art ionic conductivities, and their incorporation into test devices. Another successful aspect is the development of equipment to characterise performance of the ionic conductors and prototype harvesters in a temperature gradient, which was benchmarked against a range of conventional thermoelectric materials. The main stumbling block is the occurrence of non-Seebeck voltages in the test stacks. These are linked to ionic conductor/ electrode interface effects and typically reduce the thermoelectric voltages. These parasitic effects have so far precluded the development of the temperature charged capacitor structures we envisaged to use for energy harvesting. The parasitic voltages losses were not anticipated and understanding these is of urgent scientific and technological interest. |
| Exploitation Route | If the issues with interfacial voltages can be resolved, then it is possible to follow through on the original ideas. Further work will need to focus on microscopic understanding the root cause of the interface voltages. The results are of interest for future development of all solid-state batteries, where similar interfaces between ionic conductors and electrodes exist, but which typically do not operate in a temperature gradient. Nevertheless, the challenge of engineering good interfaces between materials is of the same importance. |
| Sectors | Energy |
| Title | Alloying and doping control in the layered metal phosphide thermoelectric CaCuP (dataset) |
| Description | Dataset to support publication. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2023 |
| Provided To Others? | Yes |
| Impact | Dataset to support publication. |
| URL | https://research-portal.st-andrews.ac.uk/en/datasets/alloying-and-doping-control-in-the-layered-meta... |
| Title | Dataset for Thermoelectric properties and Kondo transition in the pseudo-gap metals TiNiSi and TiNiGe |
| Description | Dataset to support publication. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2023 |
| Provided To Others? | Yes |
| Impact | Dataset to support publication. |
| URL | https://research-portal.st-andrews.ac.uk/en/datasets/dataset-for-thermoelectric-properties-and-kondo... |