Conventional Thermoelectrics vs Emerging 'Ionic Thermoelectric' Systems
TBA TBA
Thermoelectric Materials/TBA
Conventional, solid-state thermoelectrics are characterized by the Seebeck effect, and rely upon optimizing asymmetry in the coupled charge and heat transport to achieve efficient conversion between thermal and electrical energy.
Liquid- or gel-based electrochemical cells for waste heat harvesting (with multiple names such as thermoelectrochemical cells, thermogalvanic devices, thermocells, ionic thermoelectrics) utilize many terms and equations from the conventional thermoelectric field. However, their fundamental mechanisms of operation are radically different. The voltage in ionic systems comes from the entropy difference between the oxidized and reduced species, and current comes from their transport between two electrodes; there is often a mixture of unidirectional (short-lived, capacitive) and bidirectional (continuous, steady-state) processes. Heat transfer primarily comes from solvent molecules, which is molecular transport and often contains significant convective components.
Part of our research focuses on the accurate, total quantification and fundamental understanding of these emerging systems,[e.g. 1-2] and applications [e.g. 3-4]. We are also exploring how our new, relatively inexpensive quantification equipment and methodology can be applied to characterizing the performance of conventional, solid-state thermoelectrics.
This presentation will introduce the differences and potential synergistic opportunities for conventional and ionic thermoelectrics, our fundamental research in the area of thermoelectrochemical cells, and how our methodology could be expanded to conventional thermoelectrics.
References
[1] Buckingham & Aldous, "Thermogalvanic cells: A side-by-side comparison of measurement methods" Journal of Electroanalytical Chemistry, 2020, 872, 114280.
[2] Trosheva et al. "Direct measurement of the genuine efficiency of thermogalvanic heat-to-electricity conversion in thermocells" Chemical Science, 2022, 13, 4984.
[3] Liu et al. "Advanced Wearable Thermocells for Body Heat Harvesting" Advanced Energy Materials, 2020, 10, 2002539.
[4] Haughton-James et al. "Thermogalvanic bricks: optimising large dimension thermocells for air and water valorisation" Sustainable Energy & Fuels, 2025, 9, 1165.