Solid-State, Ionic, and Hybrid Thermoelectrics for Energy Conversion and Smart Cooling

Thermoelectric materials enable the conversion of temperature gradients into electricity and solid-state cooling through the Peltier effect, offering unique opportunities for waste-heat recovery, microcooling, thermal management, and self-powered sensing. Progress in this field depends not only on device engineering but also on fundamental chemistry, including control of crystal structure, charge carrier concentration, defect populations, and phase stability. High-performing thermoelectric systems include Bi₂Te₃- and Sb₂Te₃-based alloys, PbTe and SnTe derivatives, Mg₃Sb₂-based compounds, skutterudites, half-Heuslers, Zintl phases, oxide thermoelectrics, and conducting polymers such as PEDOT:PSS. Chemical substitution, vacancy engineering, nanocomposite formation, and interfacial reactions strongly influence electrical and thermal transport in these materials. In parallel, ionic thermoelectrics and thermogalvanic systems introduce redox- and ion-transport-based routes for harvesting low-grade heat.This Research Topic aims to advance thermoelectric materials and devices for both thermal-to-electrical energy conversion and solid-state cooling by linking fundamental chemistry with materials design and device-level requirements. We seek contributions that clarify how composition, crystal structure, charge carrier concentration, defect chemistry, phase stability, and interfacial reactions govern thermoelectric performance at different temperature ranges. The scope includes nanostructuring and nanocomposites, advances in bulk and thin-film thermoelectrics, printable and flexible platforms, and emerging concepts that combine electronic and ionic transport. Topics of interest include chemical substitution and doping strategies to improve power factor, approaches to suppress lattice thermal conductivity, methods to optimize cooling and energy conversion performance, stabilization of materials and contacts at elevated temperature, and routes to lower cost through abundant or less toxic elements. By bringing together experimental, theoretical, and computational studies, this Topic aims to define design rules that connect synthesis, microstructure, and transport with realistic device metrics.This Topic focuses on solid-state, ionic, and hybrid thermoelectric materials and devices for energy conversion and solid-state cooling, with emphasis on transport chemistry, redox processes, and scalable integration. We welcome original research articles, reviews, perspectives, and mini-reviews.Topics of interest include (but are not limited to):• Chalcogenides, skutterudites, half-Heuslers, Zintl phases, and oxide thermoelectrics• High-entropy, disordered, and intermetallic thermoelectric systems• Conducting polymers, ionic thermoelectrics, and thermogalvanic media• Low-dimensional systems, superlattices, and nanograined microstructures• Hybrid organic–inorganic composites and flexible thermoelectric devices• Band engineering, defect engineering, and phonon scattering strategies• Anisotropic, transverse, and coupled ionic–electronic thermoelectric effects• Scalable synthesis, doping control, sintering, printing, and thin-film growth• Contact layers, barrier layers, and micro-thermoelectric module design• Electrolyte and gel preparation for ionic thermoelectric devices• Measurement protocols, cooling metrics, and power-generation benchmarks• Lifetime testing, degradation mechanisms, and multiphysics modelling Topic editors: Amir Pakdel, Franck Gascoin, António Pereira Gonçalves Source: https://www.frontiersin.org/research-topics/79713/solid-state-ionic-and-hybrid-thermoelectrics-for-energy-conversion-and-smart-cooling