MULTIFUNCTIONAL CARBON FIBER EPOXY-MATRIXCOMPOSITES FOR ENERGY HARVESTING

摘要

This work provides a transformational technology that allows large-scale cost-effective thermalenergy harvesting. The technology is enabled by continuous carbon fiber polymer-matrixlightweight structural composites that have been modified for thermoelectric abilities in thethrough-thickness direction. Structural composites are in contrast to exotic and structurally weaksemiconductor materials of the prior art. Moreover, they enable self-powered structures. Thecomposite modification involves minor additives introduced to the interlaminar interface by fiberprepreg surface coating using liquid-based dispersions of thermoelectric particulate fillers(tellurium and a minor amount of bismuth telluride). Except for the coating, the composites areconventionally fabricated, thus allowing large low-cost energy-harvesting multifunctionalstructures. The large area helps reduce the electrical resistance, hence enhancing the poweroutput. The modified interlaminar interface region is 33 μm (or less) thick, thus amounting to 14vol.% (or less) of the composite. The interlaminar interface modification greatly decreases theelectrical resistivity, decreases the thermal conductivity, and increases the thermoelectric power,thereby increasing the dimensionless thermoelectric figure of merit ZT (70°C) from 2.8× 10-7 to0.38. The technology provides a new avenue for obtaining self-powered structures and a newsource of clean energy.