CoSb3-based skutterudite nanocomposites prepared by cold sintering process with enhanced thermoelectric properties

We show here for the first time use of a cold sintering process (CSP) to sinter CoSb3-based thermoelectric materials. CSP at 150 °C 90 min under uniaxial pressure 750 MPa yields pieces with relative density 86 %, which is increased around 92 % after post-annealing temperatures ≥ 500 in Ar atmosphere. The reported produces Te doped-CoSb3 nanocomposites similar morphological and structural characteristics starting nanopowders obtained by ball milling air post-thermal treatment induces grain coalescence growth, crystallite size growth as well compositional changes nanocomposite, decreasing amount main phase, CoSb3, increasing weight secondary CoSb2, up 30 wt% 600 °C. Remarkably, average valence Co, Sb absorbing atoms neither transformed nor subsequent heat treatment. functional response sintered exhibits maximum figure merit 0.12(3) room temperature This mainly due its low thermal conductivity comparison powders other approaches, it explained properties. These findings represent an attractive alternative obtaining efficient skutterudites scalable cost-effective route.