Thermoelectric Performance of Epoxy/SWCNT/PPy Ternary Nanocomposites near Room Temperature

The development of scalable, highly efficient thermoelectric (TE) materials is essential for advancing their practical applications. However, most currently available TE materials suffer from several limitations, including high production costs, toxicity, restricted performance near room temperature (RT), and generally low TE efficiency. In this study, polymer ternary nanocomposites based on single-walled carbon nanotubes (SWCNTs), polypyrrole (PPy) nanotubes, and epoxy resin were developed as n-type, efficient TE materials. These nanocomposites were produced at various PPy types and loadings, e.g., 2, 3, and 4 wt %, while the SWCNTs were fixed at 4 wt %. The TE performance was systematically evaluated over a temperature range of 213–348 K. The nanocomposite of 3 wt % PPy showed significantly enhanced TE performance. This optimized nanocomposite exhibited a power factor of 136.956 × 10–2 μW m–1 K–2 and a figure of merit of 1.065 × 10–3. Power generation measurements using a single-leg freestanding sheet module confirmed these findings. This improvement is attributed to strong π–π interactions between PPy and SWCNTs, which promote efficient charge carrier transport and interfacial compatibility. These results demonstrate that PPy-SWCNT incorporation is an effective approach to enhance the TE performance of polymer-carbon-based nanocomposites, particularly for TE applications operating near room temperature.