Chemo‐Mechanical Energy Harvesters with Enhanced Intrinsic Electrochemical Capacitance in Carbon Nanotube Yarns. Issue 32 (18th September 2022)

• Record Type: Journal Article
• Authors: Oh, Seongjae; Kim, Keon Jung; Goh, Byeonghwa; Park, Chae‐Lin; Lee, Gyu Dong; Shin, Seoyoon; Lim, Seungju; Kim, Eun Sung; Yoon, Ki Ro; Choi, Changsoon; Kim, Hyun; Suh, Dongseok; Choi, Joonmyung; Kim, Shi Hyeong
• Is Part Of: Advanced science. Volume 9:Issue 32(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-09-18
• Subjects: carbon nanotubes -- chemo‐mechanical harvesters -- energy harvesting -- intrinsic electrochemical capacitance -- matching impedance; Science -- Periodicals; 505
• DOI: 10.1002/advs.202203767
• Languages: English
• ISSNs: 2198-3844

Abstract

Abstract: 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. Abstract : Enhanced intrinsic electrochemical capacitance (IEC) in coiled carbon nanotube yarn harvesters is achieved by optimizing structural homogeneity and electrochemical accessible area. Stretching‐induced large variation in IEC generates the highest knowvolumetric electrical power in the ocean‐like environment when compared with other types of mechanical harvesters usable in the ocean.