A scalable synthesis route for multiscale defect engineering in the sustainable thermoelectric quaternary sulfide Cu26V2Sn6S32. (15th August 2020)

• Record Type: Journal Article
• Authors: Guélou, Gabin; Couder, Christophe; Bourhim, Abdelhamid; Lebedev, Oleg I.; Daneu, Nina; Appert, Florian; Juraszek, Jean; Lemoine, Pierric; Segreto, Lorraine; Guilmeau, Emmanuel
• Is Part Of: Acta materialia. Volume 195(2020)
• Page Start: 229
• Page End: 239
• Publication Date: 2020-08-15
• Subjects: Thermoelectric -- Defect engineering -- Sulfide -- Colusite -- Mechanical alloying; Materials -- Periodicals; Materials science -- Periodicals; Materials -- Mechanical properties -- Periodicals; Metallurgy -- Periodicals; Chemistry, Inorganic -- Periodicals; 620.112
• DOI: 10.1016/j.actamat.2020.05.039
• Languages: English
• ISSNs: 1359-6454

Abstract

Abstract: In recent years, thermoelectric materials inspired from the natural mineral colusite have emerged as a new class of environmentally-friendly copper-based sulfides composed of abundant elements. Herein, high performance bulk colusite Cu26 V2 Sn6 S32 materials were synthesized using mechanical alloying and spark plasma sintering of low-cost industrial-grade metal sulfides. This new synthesis route has led to the formation of various types of nano-to-microscale defects, from local Sn-site structural disorder to nano-inclusions and vanadium-rich core-shell microstructures. These multiscale defects have a strong impact over phonon scattering, making it possible to reach ultra-low lattice thermal conductivity. Simultaneously, the electrical transport properties are impacted through variations in charge carrier concentration and effective mass, leading to a synergistical improvement of both electrical and thermal properties. The resulting power factor, over 1 mW m −1 K −2 above 623 K with an average value of 0.86 mW m −1 K −2 over the temperature range 300 ≤ T / K ≤ 650 K, is the highest reported for a germanium-free colusite to date. Our optimization strategy based on defect engineering in bulk materials is an exciting prospect for new low-cost thermoelectric systems. Graphical abstract: Image, graphical abstract