Nanophase Composites as a Route to Pratical High ZT Polymer Thermoelectric Materials

Some polymers exhibit Seebeck coefficients that are 100 to 1000 times higher than those of semiconductors used in today's thermoelectric devices. Unfortunately these polymers have low electrical conductivity that results in a figure-of-merit, ZT, that is much lower than do the conventional semiconductors. Attempts to increase the conductivity of polymers by doping or micro particle addition have not proven successful in increasing ZT. The addition of low volume concentrations of nanophase metal particles (size ranging from 5 to 100nm) to conventional insulating polymers greatly increases the electrical conductivity without increasing the thermal conductivity of the composite. The anomalous conductivity enhancement demonstrated by nanophase metal particles may allow non-shunting conductivity increase in polymers with high Seebeck coefficients that would result in a high ZT for the composite material. Since theory does not allow prediction the transport properties of such nanophase materials, ICE, Inc. proposes to attempt to prepare a composite of a nanophase metal in an intrinsically conducting polymer that is known to have a high Seebeck coefficient.