PREPARATION AND THERMOELECTRIC PROPERTIES OF Cux/Bi2Te3 COMPOSITES

Abstract

Thermoelectric materials are the use of solid internal carriers to realize mutual conversion between thermal energy to electrical energy. Bismuth telluride (Bi<sub>2</sub>Te<sub>3</sub>) based thermoelectric materials are relatively mature near low temperatures. Due to the excellent conductivity of copper, the method of combining copper with a thermoelectric matrix to produce thermoelectric composite materials with better thermoelectric properties has always been a research focus in thermoelectric composite materials. Bismuth telluride thermoelectric composite materials (Cu<sub>x</sub>/Bi<sub>2</sub>Te<sub>3</sub>) samples with different mass percentages of purity (Cu) powder were prepared by spark plasma sintering (SPS) method. The influences of the Cu with different incorporation ratios on the performance of Cu<sub>x</sub>/Bi<sub>2</sub>Te<sub>3</sub> thermoelectric composites were investigated, such as differential thermal conductivity, thermal conductivity, Seeback coefficient, and ZT values. The Cu<sub>x</sub>/Bi<sub>2</sub>Te<sub>3</sub> thermoelectric composites with Cu chemical composition of 0.005 exhibited excellent Seebeck coefficients and ZT value at the heat source temperature of 325 K. The values are -289.46 μV/K and 1.69, respectively. The value of ZT is improved by about 2 times, compared with Bismuth telluride Bi<sub>2</sub>Te<sub>3</sub> thermoelectric materials.