thermoelectric performance

thermoelectric properties

lattice thermal

power factor

figure merit

seebeck coefficient

thermoelectric power

Materials Today Physics

Bi 2 Te 3 -based alloys, generally prepared by traditional zone melting or hot-pressing, have been used in commercial applications for decades. However, the zone melting method is time-consuming and usually accompanied by poor thermoelectric performance, while the hot-pressing sintering needs complex and high-cost equipment. In this work, high-performance p-type Bi 0.4 Sb 1.6 Te 3 alloy is prepared by cold pressing the ball milled Bi 0.4 Sb 1.6 Te 3 powder followed by vacuum annealing, which is more suitable for large-scale promoting with cost saving. Owing to the low lattice thermal conductivity brought by fine grains, a peak ZT value of ∼1.15 at 50 °C and an average ZT value of ∼0.84 within 30–250 °C are realized, which are comparable with the excellent performance achieved by zone melting and hot-pressing, and are even better than that of the optimized cold-pressed sample. More importantly, the thermoelectric performance here shows good repeatability from batch to batch. Our work makes the widespread application of Bi 0.4 Sb 1.6 Te 3 alloy in thermoelectric power generation and refrigeration an important step forward. • Bi 0.4 Sb 1.6 Te 3 is prepared by cold pressing the nano powder and annealing. • The sufficient connection among nanocrystals causes good electrical properties. • The ultra-fine grains bring about low thermal conductivity. • A high ZT value of ∼1.15 at 50 °C is achieved for Bi 0.4 Sb 1.6 Te 3 .

High thermoelectric performance bismuth telluride prepared by cold pressing and annealing facilitating large scale application