Tetrahedrites for Low Cost and Sustainable Thermoelectrics

Abstract

Sustainable development is the way to ensure the Human progress within the bounds of the ecological possible. In this context thermoelectric systems can play an important role. However, the price of most high-performance thermoelectric devices is high, mainly due to the use of expensive elements, which raised the interest for cheap thermoelectric materials. It is also clear that the production of competitive thermoelectric devices critically depends on other factors, like the manufacturing costs, and that the materials fabrication simplicity, reproducibility, and use of easy scale-up processes will also play a fundamental role.Tetrahedrites, with generic formula Cu10M2Sb4S13 (M = Cu, Mn, Fe, Co, Ni, Zn), are world spread sulfosalt minerals that crystallize in the cubic Cu12Sb4S13-type structure. They are environment friendly materials mainly formed by non-expensive elements. Recently, mineral based and synthetic tetrahedrites were considered as promising thermoelectric materials, with zT ~ 1 at T ~ 700 K. Though, tetrahedrite melts incongruently, the preparation of appropriate tetrahedrite samples usually requiring long-term annealing procedures. Here we present a set of systematic studies on the use of tetrahedrites as low-cost and sustainable thermoelectric materials. The raw material prices evaluation, the feasibility of rapid, scalable, cheap tetrahedrite preparation and their long term stability and resistance to oxidation under working conditions are highlighted.