Augmentation in the thermoelectric performance by integrating the natural minerals with synthetic tetrahedrite compounds

Abstract

Thermoelectric (TE) materials-based devices are useful in converting heat into electricity. The cost of thermoelectric materials is mainly incurred from the purified pure metals used to make the efficient TE device. In the current study, tetrahedrite materials are considered due to their low cost, as these materials are abundant in mining waste of copper ores and also the most extensive sulfosalt on earth. Hence, to add value addition to mine waste materials, the composite approach has been employed to integrate the natural tetrahedrite (mine waste/tailings product) materials with synthetically developed tetrahedrite materials in the lab for the current investigation. Further, the optimum quantity of mine waste addition is optimized by the systematic investigation of TE performance with varying the mine waste percentage addition to the synthetic tetrahedrite. The p-type synthetic Cu10FeZnSb4S13 (Sample-A) tetrahedrite compound and 70 (Cu10FeZnSb4S13) + 30 (natural/mine waste) (Sample-B) have been synthesized employing hot-press at 773 K along with the pristine (Cu10Fe2Sb4S13) tetrahedrite compound. Moreover, the Seebeck coefficient is increased by 36 % (220 μV/K to 300 μV/K) for Sample-B, as compared to sample A and it is ∿ 2 times higher as compared to the pristine compound. The power factor is increased by ∿ 3 times that of the Sample-A (0.05 mW/mK2 to 0.15 mW/mK2). In addition, the thermal conductivity of Sample-B compound was further reduced by 30 % than Sample-A (0.98 W/mK to 0.69W/mK) and ∿ 44 % more than the pristine compound. Finally, the zT of Sample-B increased to almost 3 times than Sample-A (0.05–0.15).