Graphene Quantum Dot Reinforced Electrospun Carbon Nanofiber Fabrics with High Surface Area for Ultrahigh Rate Supercapacitors

Abstract

High surface area, good conductivity, and high mechanical strength are important for carbon nanofiber fabrics (CNFs) as high-performance supercapacitor electrodes. However, it remains a big challenge because of the trade-off between the strong and continuous conductive network and a well-developed porous structure. Herein, we report a simple strategy to integrate these properties into the electrospun CNFs by adding graphene quantum dots (GQDs). The uniformly embedded GQDs play a crucial bifunctional role in constructing an entire reinforcing phase and conductive network. Compared with the pure CNF, the GQD-reinforced activated CNF exhibits a greatly enlarged surface area from 140 to 2032 m2 g–1 as well as a significantly improved conductivity and strength of 5.5 and 2.5 times, respectively. The mechanism of the robust reinforcing effect is deeply investigated. As a freestanding supercapacitor electrode, the fabric performs a high capacitance of 335 F g–1 at 1 A g–1 and extremely high capacitance retentions of 77% at 100 A g–1 and 45% at 500 A g–1. Importantly, the symmetric device can be charged to 80% capacitance within only 2.2 s, showing great potential for high-power startup supplies.

Self‐template porous carbon by direct activation of high‐ash coal liquefaction residue for high‐rate supercapacitor electrodes

“…Besides, C1s and O1s spectra of HPC‐700 are presented in Figure 4C and D. The high‐resolution spectra of C1s can be mounted to four individual peaks centered at 284.8, 285.9, 287.5, and 290.5 eV, referring to CC/CC, CO, CO and COOR, respectively 56,57 . The CC/CC will promote the movement of charges and thereby increase conductivity.…”

“…Besides, C1s and O1s spectra of HPC-700 are presented in Figure 4C and D. The high-resolution spectra of C1s can be mounted to four individual peaks centered at 284.8, 285.9, 287.5, and 290.5 eV, referring to C C/C C, C O, C O and COOR, respectively. 56,57 The C C/C C will promote the movement of charges and thereby increase conductivity. The O1 spectrum is further divided into three separate peaks which expose the presence of functional oxygencontaining groups, namely C O C (532.5 eV), C O (531.6 eV), and C O C (533.8 eV).…”

Chiral Graphene Hybrid Materials: Structures, Properties, and Chiral Applications

“…Graphene can be electrospun into nanofibers. [ 318–320 ] On the other hand, chiral membranes have been manufactured via electrospinning process. [ 321,322 ] It is hence hypothesized that chiral membranes based on graphene nanofibers may combine the merits of fibrous membranes and chirality.…”

Metal-Free Carbon-Based Supercapacitors—A Comprehensive Review

“…The device displayed a maximum specific capacitance of 237.3 F/g and retained exceptional energy and power output after bending at 154 • . Zhoa et al [91] reinforced carbon nanofibers with graphene quantum dots and saw an increase in specific capacitance from 115 to 335 F/g. This is due to conductive network of crystallized quantum dots embedded in the nanofiber.…”