Stabilization of Thermoelectric Properties of the Cu/Bi0.48Sb1.52Te3 Composite for Advantageous Power Generation

Bi 2 Te 3 thermoelectric materials have been developed for refrigeration around room temperature. But the ZT values decrease quickly above 400 K, which need to be improved for applications in power generation. In the present work, P -type Cu/BiSbTe alloys have been prepared via a zone melting method followed by spark plasma sintering. Due to the effects of Cu powders, the as-prepared materials exhibit a shift of the peak Seebeck coefficient value towards higher temperature and suppressed lattice thermal conductivity with increasing Cu powders. A peak ZT value as high as 0.87 has been obtained around 500 K in the BiSbTe alloy with 1 wt.% Cu powder addition, and the ZT values stabilize above 0.8 from 375 K to 550 K. This high and stable value for BiSbTe alloys at such a high temperature is very attractive for its application in power generation devices.