3-Dimensional ordered reduced graphene oxide embedded with N-doped graphene quantum dots for high performance supercapacitors
, Thuy Giang Nguyen, , , Sep-2020, In: Electrochimica Acta, 361, p. 137018
Overview
Abstract:
The development of electrode materials with high energy and power densities is timely needed. In this study, the 0-dimensional N-doped graphene quantum dots (N-GQDs) embedded into 3-dimensional porous reduced graphene oxide (N-GQD/3DrGO) hybrid materials were hydrothermally fabricated for high performance supercapacitor application. The 2 –6 nm N-GQDs with an average particle size of 4 ±0.5 nm are homogenously dispersed onto the porous 3DrGO, resulting in the increase in the spe- cific surface area with continuous meso–macroporous channels. Moreover, the bimodal pore size distri- bution with a suitable meso–macropore size range of 2.1 –77.2 nm accelerates the electron and ion transports inside N-GQD/3DrGO to improve the electrochemical performance of supercapacitor applica- tion. N-GQD/3DrGO exhibits a superior specific capacitance of 361 F g −1 at 2 A g −1 in the presence of the voltage range of -1 –1 V ( vs Ag/AgCl) using Na 2 SO 4 as the electrolyte. In addition, N-GQD/3DrGO hybrid materials show excellent long-term cycling stability, and 89.2% of the initial capacitance can be retained after 10,0 0 0 cycles. The embedded N-GQDs can minimize the re-stacking of rGO nanosheets as well as improve the pore texture and conductivity, while the 3D rGO serves as a carbon backbone to reduce the diffusion path of electrons and ions. This advantage results in a superior energy density of 111.2 −24.2 Wh kg −1 at the power density of 260 −50 0 0 W kg −1 . The excellent electrochemical perfor- mance clearly demonstrates that combination of different morphologies of graphene-based nanomaterials is a novel strategy to fabricate a superior electrode material for supercapacitor applications, which can provide a unique alternative to explore the new boundary of energy-related nanomaterials for high per- formance asymmetric energy storage devices.
| Article number | 137018 |
| Journal | Electrochimica Acta |
| Volume | 361 |
| Publication status | Published - Sep-2020 |
| ISBN | 1873-3859 |