MASSCOTE aims at advancing the knowledge of sulphides with complex crystal structures as efficient thermoelectric materials. MASSCOTE focusses on sulphide-based TE materials: transition Metal Clusters, derivated Cu12Sb4S13 tetrahedrites, and ternary Cu-Sn-S compounds. The scientific approach is based on the investigation of bulk sulphide materials including synthesis, powder processing, sintering techniques, structure and microstructure analyses, transport properties measurements and modeling..
The main targets, innovative and ambitious aspects of MASSCOTE project are: <br />-Discovery of the next generation of low cost sulphide thermoelectrics with ZT~ 1 (RT-700K), focusing on three families of sulphides: transition metal clusters, tetrahedrites and ternary Cu-Sn-S compounds. <br />-Full consolidation of bulk compounds with high thermal stability
The scientific approach consists in 3 main steps (WP): 1-synthesis and materials processing, 2- structural and physico-chemical characterization and understanding and 3-Thermoelectric properties, Modelling and Optimization.
1- In the first work package, the material will be optimized in terms of synthesis conditions and phase composition in order to optimize carrier concentration, electrical properties, and minimize thermal conductivity which affects the energy efficiency during waste heat recovery. Three families of improved material are proposed as well as material processing (mechanical alloying, SPS, microwave sintering).
2- In the second work package, due to the structural complexity of these materials associated with the nanostructure nature of mechanically alloyed precursors making them very difficult to characterize and due to the importance of understanding the materials properties (electrical and thermal), a detailed investigation of the material crystallographic structure and nanostructure features will be performed. A broad range of complementary experimental techniques will be used: x-ray and neutron diffraction techniques will provide information on samples' phase purity, composition, structure, microstructure (defects, sizes, microstrains, distributions), using both laboratory and large scale facility instruments, hence beneficiating from the complementarity of the various probes.
3- In the third work package, we will examine the electrical and thermal properties of bulk compounds. Both low and high temperature measurements will be carried out to address fundamental understanding of thermoelectric properties in relation with composition and structure, and to determine the performance of each material by determining its ZT values. Collected data will also serve modelling approaches using first principles calculations of the electronic structure and electron transport properties based on DFT techniques.
-Presence of Arsenic in natural minerals does not affect the thermoelectric properties
-Mechanical alloying of tetrahedrite composites using natural and synthetic materials
-synthesis conditions of clathrate cluster determined
-Cu12Sb4S13 and Cu4Sn7S16 phase stability determined
-Synthesis of germanite Cu22Fe8Ge4S32 based synthetic compound.
-Investigation of new colusite compositions.
-In situ neutron diffraction of different ternary/quaternary compounds
-SPS densification of clathrate cluster
-New Mo cluster synthesis
-Inelastic neutron scattering of tetrahedrites and colusites compounds.
P. Masschelein et al., Journal of Alloys and Compounds, 739, 360-367 (2018).
P. Lemoine et al., J. Solid State Chem. 247 (2017) 83-89
V. Pavan Kumar et al. Inorg. Chem. 56 (2017) 13376
MASSCOTE aims at advancing the knowledge of sulphides with complex crystal structures as efficient thermoelectric materials for the generation of electricity from renewable solar, automotive or industry energy at medium temperatures. MASSCOTE focusses on Complex sulphide-based TE materials: transition Metal Clusters compounds, derivated Cu12Sb4S13 tetrahedrites, and ternary Cu2Sn3+xS7+2x (0 = x = 1) compounds. The scientific approach is based on the investigation of bulk sulphide materials including synthesis, powder processing, sintering techniques, structure and microstructure analyses, transport properties measurements and modelling. The three academic institutes and involved people have strong complementary expertise and know-how , assessed by a significant number of common publications, for successfully reaching the objectives of MASSCOTE and bringing significant breakthroughs in terms of applicative material performance and cost.
To be completed in final version for 3rd November.
Monsieur Emmanuel Guilmeau (Laboratoire de Cristallographie et Sciences des Matériaux)
The author of this summary is the project coordinator, who is responsible for the content of this summary. The ANR declines any responsibility as for its contents.
CRISMAT Laboratoire de Cristallographie et Sciences des Matériaux
ISCR Institut des Sciences Chimiques de Rennes
IJL CNRS/ Institut Jean Lamour
Help of the ANR 562,181 euros
Beginning and duration of the scientific project: August 2016 - 36 Months