Thermoelectric and power generation properties of epoxy/SWCNT nanocomposite above and below room temperature

Scalable thermoelectric (TE) materials are of great importance for their practical applications; however, the available TE materials lack this property, in addition to their high cost, toxicity, and limited operation below room temperature (RT). In this study, highly electrically conducting single-walled carbon nanotubes (SWCNTs) were used as a networking and electrical conductivity enhancer for the epoxy matrix to form scalable and high TE performance epoxy/SWCNT nanocomposite sheet at different SWCNT loadings within the range of 2-5 wt%. Then, the TE properties, including output power, were investigated below and above RT. The Seebeck coefficient and electrical conductivity were measured in the temperature range 213-363 K. The corresponding power generation was also assessed at Delta T = 25, 45, and 65 K below and above RT conditions. The nanocomposite containing 4 wt% of SWCNT exhibits the highest electrical conductivity, recording 7.51 S m-1 at 213 K and 9.18 S m-1 at 363 K. The corresponding Seebeck coefficient values recorded - 66 mu V K-1 at 213 K and - 91 mu V K-1 at 363 K. The measured power output by a small leg module above RT reached 6.20, 11.18, and 18.0 nW at Delta T = 25, 45, and 65 K, respectively. Notably, measurements below RT showed nearly double the power output. This indicates that the epoxy/SWCNT nanocomposite is a promising TE material at low temperatures, making it a promising candidate for power generation in cold environments.