Rapid and low-cost fabrication of thermoelectric composite using low-pressure cold pressing and thermocuring methods

The tradeoff between performance and fabrication costs plays a vital role in thermoelectric application. In this paper, an efficient fabrication method for thermoelectric composite materials with low cost is presented. The mixtures of P-type Bi0.5Sb1.5Te3 (BST) powders and epoxy resin with different ratios were prepared and cold-pressed using a stainless steel die under 70 Mpa for 3 min. The composite samples were then thermo-cured at 75 °C for 3 h and tested. The composite samples demonstrated a much lower thermal conductivity of 0.55 W m−1 K−1 in comparison with 1.48 W m−1 K−1 at 125 °C of the bulk BST material. The ZT of the composite samples was measured and compared with that of the conventional Bi2Te3-based ingot. This fabrication method significantly simplifies the process of thermoelectric materials compared with traditional preparation technique.