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.The work is supported by National Natural Science Foundation of China (11172231), Changjiang Scholar Program from Ministry of Education of China, World Class University program through the National Research Foundation of Korea (R32-2008-000-20042-0), DARPA (W91CRB-11-C-0112), and National Science Foundation (CMMI-0643726 and ECCS-1028010)