High-performance Bi0.4Sb1.6Te3 alloy prepared by a low-cost method for wearable real-time power supply and local cooling

Abstract

Manufacturing low-cost, high-performance thermoelectric (TE) modules is essential for power generation and cooling. However, traditional fabrication methods (zone melting and hot pressing) are time-consuming and expensive, and the fabricated Bi2Te3-based materials have unsatisfied performance. Herein, Bi0.4Sb1.6Te3 alloys with high TE properties were prepared using cold pressing and thermal annealing processes. This preparation process is simple, time saving, and suitable for large-scale promotion. The annealing process induces the formation of pores within the grain interface, which effectively scatters low-energy charge carriers and enhance the phonon scattering. Although the electrical properties is reduced, the improved Seebeck coefficient compensates for the deteriorated electrical properties. Meanwhile, the thermal conductivity is significantly reduced. Eventually, a peak ZT of ∼1.27 is achieved at 333 K. The TE modules assembled with our Bi0.4Sb1.6Te3 alloy exhibit high output and cooling performance, with an output power density of 12.62 mW/cm2 with a temperature difference of 30 K. Furthermore, the TE module can be used for the active cooling of human skin and achieve a cooling effect of ∼8.0 °C. These results indicate that our samples are suitable for the preparation of commercially applicable TE modules and as power sources for next-generation wearable electronic devices.