Coupling Thermodiffusion and Thermogalvanic Effects in Anhydrous Ionogels for Enhanced Thermoelectric Performance

Low-grade heat from industry, electronics, and the human body is yet underutilized for sustainable power generation. Ionic thermoelectric systems harvest this heat through thermodiffusion and thermogalvanic effects. Thermodiffusion generates large ionic Seebeck coefficients through ion redistribution, but its capacitive mechanism limits sustained power delivery. In contrast, thermogalvanic cells continuously generate electricity through temperature-dependent redox reactions, although their thermopower and output power densities remain limited.
Recent studies have coupled thermodiffusion and thermogalvanic processes in a single electrolyte to combine high Seebeck coefficients with continuous power generation. Many reported systems use aqueous hydrogels containing P-type thermodiffusion sources and containing water-soluble redox couples. However, electrolyte evaporation, freezing, and humidity-dependent instability restrict long-term operation. These limitations motivate an anhydrous N-type ionogel integrating ionic-liquid-driven thermodiffusion with thermogalvanic conversion.
In this work, we present an anhydrous ionogel coupling thermodiffusion and thermogalvanic effects. The system combines an ionic liquid as the thermodiffusion source with a redox couple for continuous energy conversion. This coupling improves thermoelectric performance over thermodiffusion-only systems while maintaining continuous power generation. And additional Electrochemical analysis confirms the stability of the coupled nonaqueous electrolyte and quantifies the thermogalvanic contribution to the overall thermoelectric response, clarifying the interaction between the two mechanisms.
This study demonstrates a dual-mechanism-coupled thermoelectric conversion strategy for anhydrous N-type ionogels and supports high-performance, robust ionic thermoelectric devices for wearable electronics and self-powered systems.