Open AccessChemo‐Mechanical Energy Harvesters with Enhanced Intrinsic Electrochemical Capacitance in Carbon Nanotube Yarns
Author(s) -
Oh Seongjae,
Kim Keon Jung,
Goh Byeonghwa,
Park ChaeLin,
Lee Gyu Dong,
Shin Seoyoon,
Lim Seungju,
Kim Eun Sung,
Yoon Ki Ro,
Choi Changsoon,
Kim Hyun,
Suh Dongseok,
Choi Joonmyung,
Kim Shi Hyeong
Publication year - 2022
Publication title -
advanced science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.388
H-Index - 100
ISSN - 2198-3844
DOI - 10.1002/advs.202203767
Subject(s) - capacitance , energy harvesting , materials science , carbon nanotube , supercapacitor , electrochemistry , mechanical energy , nanotechnology , electric potential energy , electrolyte , optoelectronics , power (physics) , electrode , chemistry , physics , quantum mechanics
Predicting and preventing disasters in difficult‐to‐access environments, such as oceans, requires self‐powered monitoring devices. Since the need to periodically charge and replace batteries is an economic and environmental concern, energy harvesting from external stimuli to supply electricity to batteries is increasingly being considered. Especially, in aqueous environments including electrolytes, coiled carbon nanotube (CNT) yarn harvesters have been reported as an emerging approach for converting mechanical energy into electrical energy driven by large and reversible capacitance changes under stretching and releasing. To realize enhanced harvesting performance, experimental and computational approaches to optimize structural homogeneity and electrochemical accessible area in CNT yarns to maximize intrinsic electrochemical capacitance (IEC) and stretch‐induced changes are presented here. Enhanced IEC further enables to decrease matching impedance for more energy efficient circuits with harvesters. In an ocean‐like environment with a frequency from 0.1 to 1 Hz, the proposed harvester demonstrates the highest volumetric power (1.6–10.45 mW cm −3 ) of all mechanical harvesters reported in the literature to the knowledge of the authors. Additionally, a high electrical peak power of 540 W kg −1 and energy conversion efficiency of 2.15% are obtained from torsional and tensile mechanical energy.