Conductive nanofilm/melamine foam hybrid thermoelectric as a thermal insulator generating electricity: theoretical analysis and development

Harvesting waste energy through thermoelectric has widely gained attention to aid green energy production. Current efforts are to take advantages of nanomaterials and nanosystems because of dramatic improvements in the performance. However, its cost-effectiveness in generating a 3D configuration for a large-area use is hindered by high production cost. To overcome the present challenges, we propose a flexible and lightweight thermoelectric developed on a melamine foam using a simple dip-dry technique to self-assemble conductive nanofilms in the scaffold. Different amounts of poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS) conductive nanofilms were variedly fabricated in the foam due to altered amounts of sodium dodecyl sulfate (SDS) surfactant from 0 to 5 wt%. Together with experimental results, a theoretical model was constructed to predict thermal and electrical conductivities, indicating the strong influence of SDS to the electrical conductivity. As a result, the highest nanofilm formation in the foam structure is achieved by adding SDS at 3 wt%. The figure of merit (ZT) of thermoelectric foam is about 0.006–0.007. Our first device was also demonstrated with output voltage of 1.1 mV (ΔT = 40 K). The present study could provide the design and optimization of a hybrid thermoelectric that can act as a simultaneous thermal insulator and power generator.