Design of Cascaded Oxide Thermoelectric Generator

Abstract

This paper describes the design of two- and three-stage cascaded oxide thermoelectric generators (TEGs) for high-temperature heat recovery using reported data to optimize energy conversion efficiency. We used the general intermetallic compounds Bi 2 (Se,Te) 3 and (Bi,Sb) 2 Te 3 for the low-temperature stages and oxides of TiO 1.1 , La-doped SrTiO 3 , Na x Co 2 O 4 , and Al-doped ZnO for the higher-temperature stages. A two-stage TEG with TiO 1.1 as the p-type material and La-doped SrTiO 3 as the n-type material was found to have the highest efficiency at heat-source temperatures below 852 K, while the three-stage TEG was slightly more efficient than the two-stage TEG for heat-source temperatures above 852 K. For the three-stage TEG, the optimal boundary temperature of the second and third stages was calculated to be 698 K; at this temperature, the maximum energy conversion efficiency, 13.5%, was obtained at a heat-source temperature of 1223 K. The results showed that the designed two- and three-stage cascaded oxide TEGs have high potential for heat recovery from high-temperature waste.