2016/11/12 by Atta Ullah Khan, Kazuaki Kobayashi, Dai‐Ming Tang +9 · 1 citation
Materials Science · #Advanced Thermoelectric Materials and Devices #Thermal properties of materials #Thermal Expansion and Ionic Conductivity #Materials science #Thermoelectric effect #Thermoelectric materials #Thermal conductivity #Nano- #Phonon scattering #Porosity #Phonon #Figure of merit #Grain boundary #Alloy #Micrometer #Optoelectronics #Condensed matter physics #Nanotechnology #Engineering physics #Composite material #Microstructure #Optics #Thermodynamics
paper · pdf · doi:10.1016/j.nanoen.2016.11.016
openalex publication_date 2016/11/12 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/03
Increasing energy demands require new materials, e.g., thermoelectrics, for efficient energy conversion of fossil fuels. However, their low figure of merit (ZT) limits widespread applications. Nanostructuring has been an effective way of lowering the thermal conductivity. However, grain growth at elevated temperature is still a big concern, for otherwise expected to be long-lasting thermoelectric generators. Here, we report a porous architecture containing nano- to micrometer size irregularly shaped and randomly oriented pores, scattering a wide spectrum of phonons without employing the conventional rattling phenomenon. Lattice thermal conductivity reaches the phonon glass limit. This design yields >100% enhancement in ZT, as compared to the pristine sample. An unprecedented and very promising ZT of 1.6 is obtained for Co23.4Sb69.1Si1.5Te6.0 alloy, by far the highest ZT ever reported for un-filled skutterudites, with further benefits, i.e. rare-earth-free and improved oxidation resistance enabling simple processing.
