Economical Approach to Thermoelectric Cooling: Development of Conductive Polyethylene/Polypyrrole@Constantan Composite Using Extensional Rheological Technology
Thermoelectric cooling offers a fluoride-free alternative to vapor compression refrigeration, yet commercial adoption is constrained by low figures of merit (ZT) and high material costs. This study reports an economical fabrication route for conductive polyethylene/polypyrrole@constantan (PE/[email protected]) composites via a self-created extensional rheological technology. Pyrrole monomers are polymerized on Ni0.49Cu0.59 particles and subsequently dispersed within a polyethylene matrix under an extensional flow field, forming a continuous conductive network. The resulting composite exhibits an electrical conductivity of 1699.8 S cm−2, a thermal conductivity of 13.9 W m−1 K−1, and a ZT of 0.16 at 25 °C. A thermoelectric device integrating PE/Ppy@iron achieved a temperature reduction of 0.4 °C under 30 V/0.3 A direct current. Square-wave pulsed current excitation stabilized the cooling efficiency at its optimum level, while a custom thermal insulation system mitigated parasitic heat loss, collectively yielding a total temperature reduction of 1.6 °C. These results demonstrate a scalable, low-cost pathway for thermoelectric cooling materials, with potential for large-scale commercialization.