POS6-1055
Mixed Ionic–Electronic Conductors Enabled by Dynamic Hydroxo Complexation for Organic Thermoelectric Devices
When and Where
Nov 30, -0001
00:00 - 00:00
Room 301 (Grand Ballroom)
Presenter(s)
Jihyun Kim (Chungnam national university)
Co-Author(s)
Abstract
In organic mixed ionic–electronic conductors (MIECs), thermovoltage arises from the coupling between electronic transport and ionic Soret diffusion, with the identity of the mobile ionic species influencing both the electrochemical potential gradient and ion-transport pathways. Herein, we systematically examine the correlations between the Seebeck coefficient and ion-specific chemical descriptors, including ionic softness, hydration behavior, and the deprotonation propensity of coordinated water molecules, using PEDOT thin films as a model platform. Based on these fundamental insights, dynamic hydroxo complexation induced by metal ion species was employed to design a tetravalent cation-doped protonic conductor (TPC) film that facilitates both proton generation and the establishment of moisture-mediated ionic conduction pathways. Metal hydroxo complexes serve as high-density proton-generating Lewis acidic sites within the PEDOT:PSS matrix, enabling efficient moisture-assisted proton conduction. Following optimization of the relative humidity (RH) and microstructural aggregation behavior, the TPC thin films exhibited an exceptional ionic Seebeck coefficient of 47.4 mV K-1 at room temperature and 90% RH. To realize a device architecture suitable for wearable applications, we fabricated a solution-processed thermoelectric device in which the electrolyte layer was deposited on a hydrogel substrate and enclosed by a second hydrogel layer serving as a chamber for harvesting ambient moisture. Owing to its flexibility and ability to harvest ambient moisture, the device maintained stable operation at 30–40% RH and was integrated into a wearable thermoelectric ring module.
