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There is strong interest in developing high-frequency (HF) supercapacitors or electrochemical capacitors (ECs), which can work at the hundreds to kilo hertz range for line-frequency alternating current (AC) filtering in the substitution of bulky aluminum electrolytic capacitors, with broad applications in the power and electronic fields. Although great progress has been achieved in the studies of electrode materials for ECs, most of them are not suitable to work in this high frequency range because of the slow electrochemical processes involved. Edge-oriented vertical graphene (VG) networks on 3D scaffolds have a unique structure that offers straightforward pore configuration, reasonable surface area, and high electronic conductivity, thus allowing the fabrication of HF-ECs. Comparatively, highly conductive freestanding cross-linked carbon nanofibers (CCNFs), derived from bacterial cellulose in a rapid plasma pyrolysis process, can also provide a large surface area but free of rate-limiting micropores, and are another good candidate for HF-ECs. In this mini review, advances in these fields are summarized, with emphasis on our recent contributions in the study of these materials and their electrochemical properties including preliminary demonstrations of HF-ECs for AC line filtering and pulse power storage applications.
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Vertically Oriented Graphene Nanosheets for Electrochemical Energy Storage
Abstract Vertically oriented graphene (VG) nanosheets exhibit unique structural characteristics, such as large accessible surface area, rich edges, high electrical conductivity, open network channels, and agglomeration resistance, for electrochemical energy‐storage applications (e. g., supercapacitors, lithium‐ion batteries, etc.). In this Review article, we summarize recent progress in the design and engineering of VG‐based electrodes for high‐performance electrochemical energy technologies within the context of energy‐storage mechanisms and charge‐transfer kinetics, and include a perspective to highlight the challenges and promises in the exploitation of vertically oriented two‐dimensional carbon nanostructures for further enhancement of the performance of electrochemical energy‐storage devices.
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- PAR ID:
- 10236175
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- ChemElectroChem
- Volume:
- 8
- Issue:
- 5
- ISSN:
- 2196-0216
- Page Range / eLocation ID:
- p. 783-797
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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