Experimental Investigation of Coupled Transport Mechanisms in a PEM Based Thermoelectric Energy Converter

verfasst von: Maike Willke, Nils Eric Rahm, Stephan Kabelac
Abstract: Thermoelectric energy converters based on galvanic cells (TGC) offer the possibility of direct conversion of low-temperature waste heat into electrical energy and could therefore be a promising approach for an increase in the overall efficiency of energy conversion. Due to an externally applied heat source, a temperature gradient across the electrolyte is induced, leading to a gradient in the chemical potential of the species and an electrical potential difference between the electrodes. The aim of approaching an internal equilibrium state leads to various coupled molecular transport mechanisms taking place in the electrolyte, impacting the open circuit voltage (OCV) and the performance of the TGC. By applying the theory of non-equilibrium thermodynamics (NET) to describe these coupled processes, the interactions that occur can be characterized in more detail. In this work, a polymer electrolyte membrane (PEM)-based TGC with two H₂/H₂O electrodes of different temperatures and gas compositions is experimentally investigated. By controlling the gradients in temperature and concentration, different impacts on the resulting OCV can be identified. In addition, we present the measured coupling coefficient, representing the singular relation between the transport of the hydrogen ions inside the membrane and the electrical potential difference between the electrodes for a wide variety of working conditions.
Organisationseinheit(en): Institut für Thermodynamik
Institut für Elektrische Energiesysteme
Typ: Artikel
Journal: ENERGIES
Band: 16
ISSN: 1996-1073
Publikationsdatum: 17.07.2023
Publikationsstatus: Veröffentlicht
Peer-reviewed: Ja
ASJC Scopus Sachgebiete: Erneuerbare Energien, Nachhaltigkeit und Umwelt, Feuerungstechnik, Ingenieurwesen (sonstige), Energieanlagenbau und Kraftwerkstechnik, Energie (sonstige), Steuerung und Optimierung, Elektrotechnik und Elektronik
Ziele für nachhaltige Entwicklung: SDG 7 – Erschwingliche und saubere Energie
Elektronische Version(en): https://doi.org/10.3390/en16145434 (Zugang: Offen)