Towards tellurium-free thermoelectric modules for power generation from low-grade heat
Pingjun Ying, Ran He, Jun Mao, Qihao Zhang, Heiko Reith, Jiehe Sui, Zhifeng Ren, Kornelius Nielsch, Gabi Schierning
Abstract
Abstract Thermoelectric technology converts heat into electricity directly and is a promising source of clean electricity. Commercial thermoelectric modules have relied on Bi 2 Te 3 -based compounds because of their unparalleled thermoelectric properties at temperatures associated with low-grade heat (<550 K). However, the scarcity of elemental Te greatly limits the applicability of such modules. Here we report the performance of thermoelectric modules assembled from Bi 2 Te 3 -substitute compounds, including p-type MgAgSb and n-type Mg 3 (Sb,Bi) 2 , by using a simple, versatile, and thus scalable processing routine. For a temperature difference of ~250 K, whereas a single-stage module displayed a conversion efficiency of ~6.5%, a module using segmented n-type legs displayed a record efficiency of ~7.0% that is comparable to the state-of-the-art Bi 2 Te 3 -based thermoelectric modules. Our work demonstrates the feasibility and scalability of high-performance thermoelectric modules based on sustainable elements for recovering low-grade heat.