On the 25th, the Institute of Chemistry at the Chinese Academy of Sciences announced a significant advancement in the field of high-performance polymer thermoelectric materials. Researchers from the Institute and collaborating institutions have developed a novel high-performance polymer thermoelectric material—PMHJ film. Compared to conventional polymer films, the PMHJ film is expected to greatly enhance the thermoelectric performance of the material, providing a new approach for high-performance plastic-based thermoelectric materials. The findings have been published online in the journal Nature.
Carbon atoms can form chemical bonds with elements such as hydrogen, oxygen, nitrogen, phosphorus, and sulfur to construct various organic molecules. These molecular monomers can form high-molecular-weight polymers through periodic bonding. Currently, synthetic polymers, especially plastics, have become essential materials in everyday life and advanced technology.
Conductive polymers not only possess the flexibility, ease of processing, and low cost typical of traditional plastics but can also conduct electricity through molecular design and chemical doping. Remarkably, many conductive polymers can serve as thermoelectric materials. This means that when there is a temperature difference across the ends of a polymer film, an electromotive force (Seebeck effect) is generated; conversely, applying a voltage across a conductive polymer film can create a temperature difference.
High-performance thermoelectric materials should have a high Seebeck coefficient, high electrical conductivity, and low thermal conductivity. The ideal model is the "phonon glass-electron crystal" model, where materials act like glass to impede heat (phonon) conduction but like crystals to allow free movement of charges. Researchers explain that while polymers are widely believed to have phonon glass characteristics, many high-conductivity polymer films with ordered molecular arrangements deviate significantly from the ideal "phonon glass," limiting improvements in their thermoelectric performance.
In this study, researchers developed PMHJ films using two different polymers with distinct structural features. This film not only ensures effective charge transport but also efficiently scatters phonons and quasi-phonons.
Industry experts view this research as breaking the existing limitations of high-performance polymer thermoelectric materials, which did not rely on thermal transport control. It offers a new path for the continued development of plastic-based thermoelectric materials.
