Researchers from the Ulsan National Institute of Science and Technology (UNIST) and Nanyang Technological University in Singapore, led by Professors Hyun-Wook Lee, Dong-Hwa Seo and Seok Woo Lee, have made significant strides in harnessing low-grade heat sources, aiming to convert them into efficient energy. They've achieved this through the development of a highly efficient Thermally Regenerative Electrochemical Cycle (TREC) system capable of converting small temperature differences into usable energy, according to a Sept. 14 press release on Eurekalert.
Low-grade heat sources have posed challenges for conventional energy-harvesting systems. TREC systems stand out by integrating battery functionality with thermal energy harvesting. The team's research focused on enhancing TREC systems by exploring structural vibration modes.
Their analysis revealed that even minute amounts of water induce strong structural vibrations within cyanide ligands’ A1g stretching mode, significantly contributing to a larger temperature coefficient (ɑ) within a TREC system. Using these insights, they designed and implemented a highly efficient TREC system using a sodium-ion-based aqueous electrolyte.
The potential applications for TREC systems are extensive, especially in wearable technologies and devices with small temperature differences. By efficiently capturing and converting low-grade heat into usable energy, TREC systems offer promise for next-generation secondary batteries.
The study's findings, published ahead of official publication in Advanced Materials, were supported by various research funds, including the 2023 Research Fund of UNIST, Individual Basic Science & Engineering Research Program, and the National Center for Materials Research Data through the National Research Foundation of Korea, funded by the Ministry of Science and ICT.