A scalable synthesis route for multiscale defect engineering in the sustainable thermoelectric quaternary sulfide Cu26V2Sn6S32

Gabin Guelou (1) , Christophe Couder (1) , Abdelhamid Bourhim (1) , Oleg Lebedev (1) , Nina Daneu (2) , Florian Appert (3) , Jean Juraszek (3) , Pierric Lemoine (4) , Lorraine Segreto (5) , Emmanuel Guilmeau (1)

1 CRISMAT - Laboratoire de cristallographie et sciences des matériaux
2 IJS - Jozef Stefan Institute [Ljubljana]
3 GPM - Groupe de physique des matériaux
4 ISCR - Institut des Sciences Chimiques de Rennes
5 TRIBOTECC GMBH

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 Cu26V2Sn6S32 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.

Mots clés: Mechanical alloying; Mechanical alloying; Thermoelectric; Defect engineering; Sulfide; Colusite; Mechanical alloying; Mechanical alloying

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Gabin Guelou, Christophe Couder, Abdelhamid Bourhim, Oleg Lebedev, Nina Daneu, et al.. A scalable synthesis route for multiscale defect engineering in the sustainable thermoelectric quaternary sulfide Cu26V2Sn6S32. Acta Materialia, 2020, 195, pp.229-239. ⟨10.1016/j.actamat.2020.05.039⟩. ⟨hal-02882105⟩