Harvesting energy from low-grade heat based on nanofluids

Abstract

Conventional thermoelectric materials have limited capability of scavenging electrical energy from low-grade heat (LGH). Based on the capacitive effect of liquid-solid interface in a nanoconfinement, we investigate a novel energy harvesting mechanism which is based on the thermally sensitive ion/charge distribution of electrolytes confined in nanopores. The mechanism is elucidated using comprehensive molecular dynamics (MD) simulations. The effective thermal sensitivity, effective figure of merit, and thermal-to-electric energy conversion efficiency of the nanofiuidic system compare favorably with respect to the conventional thermoelectric materials. The result of a preliminary thermal-to-electrical energy conversion experiment on a nanoporous carbon is presented, to qualitatively show the feasibility of the approach. (C) 2012 Elsevier Ltd. All rights reserved.