High-Performance Multifunctional Graphene Yarns: Toward Wearable All-Carbon Energy Storage Textiles

Abstract

The successful commercialization of smart wearable garments is hindered by the lack of fully integrated carbon-based energy storage devices into smart wearables. Since electrodes are the active components that determine the performance of energy storage systems, it is important to rationally design and engineer hierarchical architectures atboth the nano- and macroscale that can enjoy all of the necessary requirements for a perfect electrode. Here we demonstrate a large-scale flexible fabrication of highly porous high-performance multifunctional graphene oxide (GO) and rGO fibers and yarns by taking advantage of the intrinsic soft self-assembly behavior of ultralarge graphene oxide liquid crystalline dispersions. The produced yarns, which are the only practical form of these architectures for real-life device applications, were found to be mechanically robust (Young's modulus in excess of 29 GPa) and exhibited high native electrical conductivity (2508 ± 632 S m(-1)) and exceptionally high specific surface area (2605 m(2) g(-1) before reduction and 2210 m(2) g(-1) after reduction). Furthermore, the highly porous nature of these architectures enabled us to translate the superior electrochemical properties of individual graphene sheets into practical everyday use devices with complex geometrical architectures. The as-prepared final architectures exhibited an open network structure with a continuous ion transport network, resulting in unrivaled charge storage capacity (409 F g(-1) at 1 A g(-1)) and rate capability (56 F g(-1) at 100 A g(-1)) while maintaining their strong flexible nature.

Chemically converted graphene: scalable chemistries to enable processing and fabrication

“…4 In this context, a series of graphene-based macroscopic structures such as strong and highly conducting fibers and high performance supercapacitors have been fabricated employing LCGO. 3,21 The key advantage of LCGO is its self-alignment. The controllable rheology of LCGO dispersions make them ideal for fiber fabrication.…”

“…For example, chemical vapor deposition has predominantly been used to produce thin, highly conducting films for electronic/optoelectronics or bioelectronics 11 or for optically transparent films. [12][13][14] Chemically converted graphene (CCG) has been used to form electrodes for energy conversion (solar cells) and storage (batteries/capacitors), [15][16][17][18][19][20][21][22][23] industrial catalysis, 24 chemical and bio-sensing applications 25 as well as polymer composites with improved mechanical and electrical properties. 26,27 The difference in the kinds of applications suitable for each type of graphene preparation largely reflects the graphene sheet or platelet size produced, with mechanical or thermal exfoliation typically resulting in large single or several layer sheets that are challenging to handle and fabricate into devices, whereas chemical exfoliation produces smaller dispersible platelets that can be more readily processed and produced on a large scale.…”

Fiber‐Type Solar Cells, Nanogenerators, Batteries, and Supercapacitors for Wearable Applications

“…Flexible yarn supercapacitors have linear or 1D architecture and offer several advantages over supercapacitors with planar or 2D architecture and 3D forms 133, 134, 135, 136. Planar supercapacitors usually have their rear electrode fabricated from metal sheets, foams, papers, or textile substrates 105, 137, 138, 139.…”

“…Several successful cables and fibers for wearable applications were developed using carbon, CNT, and graphene as active materials for energy storage 129, 133, 146, 173, 174, 175. A polypyrrole (PPy)–MnO 2 –CNT–cotton thread‐based cable was developed using a three‐step process 128.…”

Characterisation of graphene fibres and graphene coated fibres using capacitively coupled contactless conductivity detector

“…6 The availability and liquid crystalline properties of the graphene oxide (GO) sheets, 7,8 together with the use of wet-spinning technology 9 has accelerated the progression of the manufacture of ultra-strong and electrically conducting GBFs. 5,[10][11][12][13][14][15] However, wet-spinning has some limitations in performance and requires precise control of formulation in the spinning dope dispersions, conditions within the coagulation bath, with each step affecting final fibre morphology. Although the cost of processing GBFs is much lower than those of other carbon fibres, including carbon nanotube (CNT) containing fibres, the strength and electrical properties are poorer.…”