Advancements in flexible and wearable electronics have led to the development of self-powered, wearable systems. Thermoelectric generators (TEGs) offer promising solutions toward self-powered energy harvesting from body heat. However, previously developed TEGs are large-sized owing to their heat sinks. Hence, high-quality heat sinks are required for flexible TEGs with a small size and high power for wearable devices. Herein, a TEG integrated with a flexible, micron-thin poly(vinylidene fluoride-co-hexafluoropropylene) radiative-cooled heat sink, with an emissivity of 97.47%, is proposed. The TEG with the radiative heat sink (TEG_rad) generates power by depositing heat into a cold space (temperature of 3 K) through passive radiative cooling. Thus, TEG_rad achieved a power density of 12.48 µW/cm2 with a temperature difference (ΔT) of 1.9 °C, higher than those of flexible TEGs that were previously reported, based on body heat harvesting under natural convection. Further, TEG_rad is not only more than two times compact, but also delivers high power output compared with a TEG with a bulky finned heat sink. Moreover, a flexible lithium–sulfur (Li-S) battery was coupled with TEG_rad to store the generated power for uninterrupted power supply to a self-powered wearable system.
Bibliographical noteFunding Information:
This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government ( MEST ) ( NRF-2018K1A3A1A20026439 ). This work was supported by the Technology Innovation Program (or Industrial Strategic Technology Development Program) ( 20007031 , 3D all solid-state battery and the related systems for electrical vehicle with 600 km mileage by 1 min charging) funded by the Ministry of Trade, Industry & Energy (MOTIE, Korea).
© 2021 Elsevier Ltd
All Science Journal Classification (ASJC) codes
- Renewable Energy, Sustainability and the Environment
- Materials Science(all)
- Electrical and Electronic Engineering