Thermoelectric high-entropy oxides for power supply in the space equipment

Onboard energy supply in outer space poses significant challenges due to thermal, shock, and reliability requirements while maintaining low volume and mass. Thermoelectrics qualify as promising power generators for a space environment, producing energy from temperature gradients with simple device designs suitable for reliable power supply under harsh operating conditions. However, material design hurdles, particularly the interdependence of thermal and electric conductivities, have not yet allowed reaching energy-conversion efficiencies competing with photovoltaic technologies. Herein, recently discovered high-entropy oxides (HEOs) may bring paradigm shifts, offering novel and promising research perspectives due to so-called cocktail effects, intrinsic atomic disorder and crystal structure distortion, as well as high temperature and pressure resistance. This offers new material design approaches to partially decouple electronic and thermal conductivity, without compromising other oxide ceramic benefits particularly relevant to thermoelectric material research. In this co-funded project, advances made in the synthesis of HEOs with compositional and crystallographic control in the host project will allow the production of a series of HEOs required to explore the large compositional range they offer. The element mixture will be selected to modify the charge carrier density, disorder and distortion in the crystal structure. After microstructural engineering through advanced sintering, thorough microstructural and property characterization will yield a systematic chemistry-structure-property map for HEO-based thermoelectric material optimization. It will thus form the foundation of a technology roadmap for highly efficient and versatile thermoelectric devices, ultimately offering sustainable thermoelectric power generators for space and terrestrial energy supply needs.