Hierarchically Structured Nitrogen-Doped Multilayer Reduced Graphene Oxide for Flexible Intercalated Supercapacitor Electrodes

Abstract

Intercalated flexible electrodes for energy storage devices have drawn significant research interests as they can provide high energy densities for powering electronics without sacrificing the overall flexibility. Herein, we report an intercalated reduced graphene oxide/polyacrylonitrile (rGO/PAN) flexible supercapacitor electrode fabricated via a layer-by-layer wet electrospinning (LLwES) process with diluted graphene oxide (GO) solution as the coagulation liquid and subsequent thermal reduction treatment. It was observed that a thin GO film was established on individual PAN nanofiber layer after the wet electrospinning process, while the subsequent thermal reduction of GO led to simultaneous stabilization of the PAN fibers and the creation of an interesting three-dimensional hierarchical carbon nanostructure suitable for flexible, high-performance electrochemical capacitor (EC) electrodes. The formation of gases during the thermal treatment expanded the electrospun PAN fiber layers and resulted in the formation of intercalated nitrogen-doped porosities. The resulting LLwES rGO/PAN system, thermally treated in a nitrogen atmosphere, demonstrated exceptional double-layer capacitance of 221 F/g at 10 mV/s, a controllable electrical conductivity of 125 S/m, and a stable cycling performance retaining a slightly increased capacitance after 10000 cycles.

Structural Modulation of Exfoliated Graphene via a Facile Postultrasonication Treatment toward Enhanced Electrochemical Properties of Supercapacitor Electrode

“…Among all samples, EG 480 shows the best rate capability owing to the combination of its large surface area and high electrical conductivity. 58,59 EIS characterization was conducted to map the trend of specific capacitance among the samples. The result of this measurement is depicted as a Nyquist plot in Figure 6c and then modeled by using an equivalent circuit in Figure S6.…”

“…The rate capability of the prepared electrodes was measured at various current densities, and the results are depicted in Figure S5. Among all samples, EG 480 shows the best rate capability owing to the combination of its large surface area and high electrical conductivity. , …”

Effect of H2SO4/H2O2 pre-treatment on electrochemical properties of exfoliated graphite prepared by an electro-exfoliation method

“…Even though EG 95 : 5 and EG 100 : 0 showed a similar degree of exfoliation, more electrically conductive EG 95 : 5 enabled higher electron mobility on the electrode surface, leading to the higher specic capacitance of this sample. 14,59,60 Fig . 9(b) shows the CV plots of EG 95 : 5 sample measured at three different voltage windows, i.e., À0.9 to 0 V, À1.2 to 0 V, and À1.4 to 0 V. It can be seen that the pseudo-rectangular form of the CV plots could be maintained down to À1.4 V, suggesting that this sample owns the high potential to be applied as electrode materials for the wide voltage window supercapacitor.…”

Direct‐Writing of Multi‐Functional Photo‐Reduced Graphene Oxide Fabric (rGOf) at the Liquid‐Air Interface with Tunable Porosity

“…There has been a fast-paced progress in the field of carbon nanomaterials, with the emergence of novel carbon nanostructures, such as carbon nanotubes, [1] graphene, [2,3] carbon quantum dots, [4] and fullerene. [5] With their ideal mechanical, electrical, optical properties, along with their chemical stability, carbon nanostructures offer tremendous potential for applications in the field of energy storage, [6] soft robotics, [7] tactile sensing, [8] chemical sensing, [9] flexible circuitry, [10] among many the rGO network. Additionally, with all GO photoreduction mechanisms, attempts have mainly focused on using deposited GO films, [21] or directly creating laser-induced graphene on suitable substrates such as polyimide (PI), [22] however, these strategies lacked flexibility and cannot be universally adapted for other substrate materials.…”

“…There has been a fast‐paced progress in the field of carbon nanomaterials, with the emergence of novel carbon nanostructures, such as carbon nanotubes, [ 1 ] graphene, [ 2,3 ] carbon quantum dots, [ 4 ] and fullerene. [ 5 ] With their ideal mechanical, electrical, optical properties, along with their chemical stability, carbon nanostructures offer tremendous potential for applications in the field of energy storage, [ 6 ] soft robotics, [ 7 ] tactile sensing, [ 8 ] chemical sensing, [ 9 ] flexible circuitry, [ 10 ] among many others. Synthesis of graphitic materials had been costly, however, over the past decade, the cost has decreased drastically following the discovery of large‐scale batch production techniques.…”