Compact and low loss electrochemical capacitors using a graphite / carbon nanotube hybrid material for miniaturized systems
By Li, Qi; Sun, Shuangxi; Smith, Anderson D.; Lundgren, Per; Fu, Yifeng; Su, Peng; Xu, Tao; Ye, Lilei; Sun, Litao; Liu, Johan; Enoksson, Peter
Published in Journal of Power Sources
2019
Abstract
With the establishment of the internet of things (IoT) and the rapid development of advanced microsystems, there is a growing demand to develop electrochemical capacitors (ECs) to replace bulky electrolytic capacitors on circuit boards for AC line filtering, and as a storage unit in energy autonomous systems. For this purpose, ECs must be capable of handling sufficiently high signal frequencies, display minimum energy loss through self-discharge and leakage current as well as maintaining an adequate capacitance. Here, we demonstrate ECs based on mechanically flexible, covalently bonded graphite/vertically aligned carbon nanotubes (graphite/VACNTs) hybrid materials. The ECs employing a KOH electrolyte exhibit a phase angle of ?84.8