Tellurium‐Free, Sustainable Thermoelectric Device for Mid‐Temperature Waste Heat Recovery

ABSTRACT Famatinite (Cu₃SbS₄, p‐type) and chalcopyrite (CuFeS₂, n‐type) are well‐recognized sustainable minerals with good intermediate‐temperature thermoelectric performance. In this article, we utilize the inherent thermoelectric properties of these compounds to demonstrate real‐time operational performance as a coupled thermoelectric generator (TEG) for waste heat recovery applications. First, we synthesized the polycrystalline and nano‐grained famatinite and chalcopyrite materials with high purity through a sustainable synthesis process of mechanical alloying followed by hot pressing. A maximum output power of ~5 mW by the developed TEG was demonstrated while harvesting from a waste heat source of 723 K. Furthermore, the TEG performance via computational simulations for varied thermal gradients was validated. Our results highlight the sustainable development of thermoelectric power generator from earth‐abundant minerals having strong stability and capacity to convert waste heat to electricity, which opens a new direction for fabricating a low‐cost TEG for intermediate‐temperature applications.