CoSb3 based thermoelectric elements pre-requisite for device fabrication

Abstract

Conversion of waste heat into useful electrical energy employing thermoelectric (TE) technology can improve power generation. However, the synthesis of efficient TE elements is critically challenging in the fabrication of the TE device. In this work, p- and n-type TE elements (single leg) were synthesized by using CoSb3 skutterudites based optimized compositions (Fe0·25Co0·75Sb2·965Se0.035 and Ni0·07Co0·93Sb2·94Te0.06, respectively), and CoSi2 has been used as a contact material. The synthesis route of the TE elements is a combination of arc melting and spark plasma sintering, which is a short and cost-effective approach. Synthesized TE elements were characterized for the device performance parameters at different temperature gradients (ΔT), employing a TE conversion efficiency evaluation system (Mini-PEM). The maximum current ∼1.9 A and ∼1.4 A has been drawn, while the maximum output voltage ∼9.8 mV and ∼19 mV was attained by the p- and n-type TE elements, respectively. Finally, the output power has been evaluated, which was found to be ∼5.26 mW at ΔT∼ 471 °C for p-type TE element, and ∼6.79 mW at ΔT∼ 465 °C for n-type TE element.