Robust Homogeneous Segmented Power Generator Driven by Sb ₂ Te ₃ ‐Based Thermoelectrics

Abstract

Abstract Thermoelectric (TE) technology offers a promising solution for waste heat recovery, particularly in applications involving abundant low‐grade heat (<650 K). However, for over half a century, TE power generators have predominantly relied on Bi 2 Te 3 alloys with limited efficiencies below 7%. Herein, Cd and S are doped into Sb 2 Te 3 to promote microstructural regulation characterized by dense twin boundaries and dislocations, resulting in a 45% reduction of lattice thermal conductivity at 300 K. Combined with the optimized density‐of‐states effective mass and expanded band gap, the Cd 0.04 Sb 1.96 Te 2.94 S 0.06 sample attains a peak ZT of 1.1 at 650 K and an average ZT of 1.0 from 500 to 650 K, while exhibiting remarkable compressive and bending strengths of 197 and 56 MPa. Most importantly, a well‐designed, homogeneous segmented TE power generator, constructed entirely from Bi–Sb–Te alloys, achieves a remarkable efficiency of 9.3% under a temperature gradient of 350 K, as certified by third‐party validation. This work provides new insights into extending the operation temperature of Bi 2 Te 3 , demonstrating great potential for low‐grade waste heat harvest.