skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Explore Research Products in the PAR
It may take a few hours for recently added research products to appear in PAR search results.


Title: Carbon Nanotube Fiber-Based Wearable Supercapacitors—A Review on Recent Advances
As wearable electronic devices are becoming an integral part of modern life, there is a vast demand for safe and efficient energy storage devices to power them. While the research and development of microbatteries and supercapacitors (SCs) have significantly progressed, the latter has attracted much attention due to their excellent power density, longevity, and safety. Furthermore, SCs with a 1D fiber shape are preferred because of their ease of integration into today’s smart garments and other wearable devices. Fiber supercapacitors based on carbon nanotubes (CNT) are promising candidates with a unique 1D structure, high electrical and thermal conductivity, outstanding flexibility, excellent mechanical strength, and low gravimetric density. This review aims to serve as a comprehensive publication presenting the fundamentals and recent developments on CNT-fiber-based SCs. The first section gives a general overview of the supercapacitor types based on the charge storage mechanisms and electrode configuration, followed by the various fiber fabrication methods. The next section explores the different strategies used to enhance the electrochemical performance of these SCs, followed by a broad study on their stretchability and multifunctionality. Finally, the review presents the current performance and scalability challenges affecting the CNT-based SCs, highlighting their prospects.  more » « less
Award ID(s):
2016484
PAR ID:
10417472
Author(s) / Creator(s):
; ;
Date Published:
Journal Name:
Energies
Volume:
15
Issue:
18
ISSN:
1996-1073
Page Range / eLocation ID:
6506
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. ; ; (, Micromachines)
    Future wearable electronics and smart textiles face a major challenge in the development of energy storage devices that are high-performing while still being flexible, lightweight, and safe. Fiber supercapacitors are one of the most promising energy storage technologies for such applications due to their excellent electrochemical characteristics and mechanical flexibility. Over the past decade, researchers have put in tremendous effort and made significant progress on fiber supercapacitors. It is now the time to assess the outcomes to ensure that this kind of energy storage device will be practical for future wearable electronics and smart textiles. While the materials, fabrication methods, and energy storage performance of fiber supercapacitors have been summarized and evaluated in many previous publications, this review paper focuses on two practical questions: Are the reported devices providing sufficient energy and power densities to wearable electronics? Are the reported devices flexible and durable enough to be integrated into smart textiles? To answer the first question, we not only review the electrochemical performance of the reported fiber supercapacitors but also compare them to the power needs of a variety of commercial electronics. To answer the second question, we review the general approaches to assess the flexibility of wearable textiles and suggest standard methods to evaluate the mechanical flexibility and stability of fiber supercapacitors for future studies. Lastly, this article summarizes the challenges for the practical application of fiber supercapacitors and proposes possible solutions. 
    more » « less
  2. ; ; (, Journal of Materials Chemistry A)
    Hagfeldt, Anders (Ed.)
    Supercapacitors are widely recognized as a favorable option for energy storage due to their higher power density compared to batteries, despite their lower energy density. However, to meet the growing demand for increased energy capacity, it is crucial to explore innovative materials that can enhance energy storage efficiency. Recent research has focused on investigating various electrode materials for use in supercapacitors, with particular attention given to MXenes. MXenes exhibit immense potential for energy storage due to their unique characteristics, including a 2D van der Waals layered structure, small band gaps, hydrophilic surface, excellent electrical conductivity, high specific surface area, and active redox sites on the surface facilitated by transition metals. These attributes collectively contribute to their promising stability, energy and power density, and overall lifespan. This comprehensive review explores a diverse array of topics pertaining to the latest 2D MXene-based supercapacitor electrodes. It encompasses discussions on different synthesis methods, electrode structures, the underlying working mechanisms, and the impact of electrolytes on supercapacitor performance. Additionally, a concise overview of various types of MXene materials is presented, ranging from titanium-based MXenes to niobium-based MXenes, vanadium-based MXenes, molybdenum-based MXenes, and tantalum-based MXenes. Furthermore, this review focuses on electronic structure engineering strategies such as heterostructures based on MXenes, heteroatom-doping based on MXenes, polymer based MXenes, and ternary composites based on MXenes, all of which contribute to improving the electrochemical performance of supercapacitors. The review thoroughly examines the advantages and disadvantages of MXene-based supercapacitor electrodes, offering a comprehensive understanding of their strengths and limitations. Additionally, it discusses the structural stability of MXene-based electrodes after electrochemical testing, as well as their applications in daily human life, particularly focusing on the uses of MXene-based flexible wearable energy storage for real-world applications. In the end, the challenges and prospects of MXenes in supercapacitors are discussed. 
    more » « less
  3. ; ; ; ; ; ; (, Polymer International)
    From wool to Kevlar, one-dimensional (1D) fiber has experienced the transition from clothing materials to structural applications in the past centuries. However, the recent advancements in tooling engineering and manufacturing processes have attracted much attention from both academia and industry to fabricate novel, versatile fibers with unique microstructures and unprecedented properties. This mini-review focuses on the fabrication techniques of porous, coaxial, layer-by-layer, and segmented fibers with continuous solution and melt fiber spinning methods. In each section of this review article, the unique structure-related applications, including intelligent devices, healthcare devices, energy storage systems, wearable electronics, and sustainable products, are discussed and evaluated. Finally, the combination of additive manufacturing (AM) for 1D fiber patterning in two-dimensional (2D) and three-dimensional (3D) devices, in addition to challenges in the reviewed fiber microstructures, is briefly introduced in the conclusion section. 
    more » « less
  4. ; ; ; ; ; (, Advanced Materials Technologies)
    Abstract Stretchable supercapacitors (SCs) have attracted significant attention in developing power‐independent stretchable electronic systems due to their intrinsic energy storage function and unique mechanical properties. Most current SCs are generally limited by their low stretchability, complicated fabrication process, and insufficient performance and robustness. This study presents a facile method to fabricate arbitrary‐shaped stretchable electrodes via 4D printing of conductive composite from reduced graphene oxide, carbon nanotube, and poly(3,4‐ethylenedioxythiophene) polystyrene sulfonate. The electrode patterns of an arbitrary shape can be deposited onto prestretched substrates by aerosol‐jet printing, then self‐organized origami (ridge) patterns are generated after releasing the substrates from holding stretchers due to the mismatched strains. The stretchable electrodes demonstrate superior mechanical robustness and stretchability without sacrificing its outstanding electrochemical performance. The symmetric SC prototype possesses a gravimetric capacitance of ≈21.7 F g−1at a current density of 0.5 A g−1and a capacitance retention of ≈85.8% from 0.5 to 5 A g−1. A SC array with arbitrary‐shaped electrodes is also fabricated and connected in series to power light‐emitting diode patterns for large‐scale applications. The proposed method paves avenues for scalable manufacturing of future energy‐storage devices with controlled extensibility and high electrochemical performance. 
    more » « less
  5. ; ; ; (, Advanced Materials Technologies)
    Abstract Developing intelligent wearable energy storage devices that can endure harsh conditions is of interest for emerging applications in next‐generation electronics. Despite recent success in exploring functional materials for sophisticated self‐adaptivity in energy storage devices, it remains challenging to obtain both high reliability and superior performance. Herein, a novel method for fabricating micropatterned wearable thermoresponsive supercapacitors via direct ink writing (DIW) technique is reported. Thermal runaway of typical electrochemical storage devices with high power delivery capability can cause serious safety problems. The proposed temperature‐dependent structure works as self‐protection against the common thermal runaway issues of electrochemical energy storage devices. Such construction provides an automatic adjustment as high as 8 F g−1in specific capacitance, resulting in an overall heat reduction by up to 40%. The printing resolution of the electrodes (175 µm) is among the best in recently reported planar carbon‐based energy storage devices by DIW technique. Manufacturing‐related parameters such as time‐dependent printing speed and curing temperature are also investigated to fabricate this integrated design with varied materials and accuracy. This strategy shows tremendous promise for future intelligent energy storage devices. 
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Save / Share this Record
  • Send to Email