Robust Single‐Walled Carbon Nanotube‐Infiltrated Carbon Fiber Electrodes for Structural Supercapacitors: from Reductive Dissolution to High Performance Devices

Abstract

Multifunctional electrodes for structural supercapacitors are prepared by vacuum infiltration of single-walled carbon nanotubes (SWCNTs) into woven carbon fibers (CFs); the use of reductive charging chemistry to form nanotubide solutions ensured a high degree of individualization. The route is highly versatile, as shown by comparing four different commercial nanotube feedstocks. In film form, the pure nanotubide networks ("buckypapers") are highly conductive (up to 2000 S cm −1 ) with high surface area (>1000 m 2 g −1 ) and great electrochemical performance (capacitance of 101 F g −1 , energy density of 27.5 Wh kg −1 and power density of 135 kW kg −1 ). Uniformly integrating these SWCNT networks throughout the CF fabrics significantly increased electrical conductivity (up to 318 S cm −1 ), surface area (up to 196 m 2 g −1 ), and in-plane shear properties, all simultaneously. The CNT-infiltrated CFs electrodes exhibited intrinsically high specific energy (2.6-4.2 Wh kg −1 ) and power (6.0-8.7 kW kg −1 ) densities in pure 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMIM TFSI) electrolyte. Multifunctional structural supercapacitors based on CNT-coated CFs offer a substantial increase in capacitive performance while maintaining the tensile mechanical properties of the as-received CF-based composite. This non-damaging approach to modify CFs with highly graphitic, high surface area nanocarbons provides a new route to structural energy storage systems.

Reduced Graphene Oxide-Supported SrV4O9 Microflowers with Enhanced Electrochemical Performance for Sodium-Ion Batteries

“…The capacity decreased slightly to 265.7 mAh g −1 after 310 cycles, demonstrating good cycling performance at a high rate. The improved electrochemical performance of the SrV 4 O 9 @rGO composite can be attributed to the large aspect ratio of the composite and improved electrical conductivity [ 43 , 44 ] ( Figure 5 f).…”

Dynamic Performance of Hybrid Infrared Modulator Based on Single‐Walled Carbon Nanotubes and Ionic Liquid Enabling Fast Response

“…In contrast, the larger SWNT bundles create a highly porous network that is a conductive scaffold suitable for electrochemical energy storage applications. [ 51 ] This porous structure facilitates the unimpeded flow of ions, thereby preventing mass transport limitations in electrochemical devices. [ 52 ] The frequency response of the IR modulator in this study corresponds to that of an RC low‐pass filter, allowing low‐frequency signals to pass through while attenuating or blocking high‐frequency signals.…”

A critical review of structural supercapacitors and outlook on future research challenges

“…The capacitance was poor, with the CNT grafted CF presenting the best performance of 10 mF/g (normalised by device mass) whilst the CNT sized CF presented the best mechanical performance. A reductive dissolution method has been used which gave a capacitance of 13.26 F/g and 0.173 F/g for the liquid and structural electrolyte, respectively (normalised by active mass), with the latter achieving tensile modulus and strength of 17.2 GPa and 245 MPa, respectively [40]. Comparisons between WCF, MWCNTs and their hybrids using a liquid electrolyte (PEO/EC/LiClO 4 ) have presented active mass normalised capacitances of 3.78 F/g, 12.49 F/g and 2.6 F/g, respectively [41].…”