Natural mineral tetrahedrite as a direct source of thermoelectric materials

Background: Thermoelectric (TE) materials make possible the direct conversion of waste heat into electricity potentially improving energy efficiency or providing an alternative energy source. TE materials experience the thermoelectric effect whereby voltage is generated when there is a temperature gradient within the material. Since 1995 advances in engineering have generated materials with marked improvement in their ability to convert heat into electricity. Unfortunately many of the materials developed are not suitable for large scale applications due to complex synthesis requirements and expensive or toxic starting materials. Additionally supply for many of these expensive elements and compounds may be limited when they have competing applications. Increasing the implementation of TE devices requires new TE materials that are inexpensive environmentally-friendly easy to synthesize and abundantly available. Technology Description: Michigan State University has developed an inexpensive production process for a class of thermoelectric compounds based on the natural tetrahedrite structure. Tetrahedrite is a common compound and is often discarded as waste during silver mining. From this raw state the tetrahedrite is milled into a powder which is then doped to increase resistivity increasing the Seebeck coefficient while lowering thermal conductivity. The powder is then pressed into a brick or puck which can be cut to the final configuration. The end product is a high performance thermoelectric material that functions as well as comparable (and much more expensive) materials. Applications: Energy scavenging (e.g. automotive power generation etc.) energy generation alternative energy source.


1) High performance: equivalent to some of the most advanced materials used in the industry. 2) Ease of production: these tetrahedrite pucks can be rapidly produced. 3) Inexpensive: this method uses common waste products as a base material instead of expensive purified elements that require costly manufacturing processes. 4) Safe: this technology requires no toxic reagents or long annealing processes.

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