Nitrogen‐Superdoped 3D Graphene Networks for High‐Performance Supercapacitors

Abstract

An N-superdoped 3D graphene network structure with an N-doping level up to 15.8 at% for high-performance supercapacitor is designed and synthesized, in which the graphene foam with high conductivity acts as skeleton and nested with N-superdoped reduced graphene oxide arogels. This material shows a highly conductive interconnected 3D porous structure (3.33 S cm ), large surface area (583 m g ), low internal resistance (0.4 Ω), good wettability, and a great number of active sites. Because of the multiple synergistic effects of these features, the supercapacitors based on this material show a remarkably excellent electrochemical behavior with a high specific capacitance (of up to 380, 332, and 245 F g in alkaline, acidic, and neutral electrolytes measured in three-electrode configuration, respectively, 297 F g in alkaline electrolytes measured in two-electrode configuration), good rate capability, excellent cycling stability (93.5% retention after 4600 cycles), and low internal resistance (0.4 Ω), resulting in high power density with proper high energy density.

Structural Rigging of Lignin Precursors for Customized Porous and Graphene‐Like Carbons towards Enhanced Supercapacitive Performance in Aqueous and Non‐Aqueous Electrolytes

“…More importantly, the rich structural defects in ALC‐6000‐800 facilitate the electrolyte ions to access storage sites, whereas the low density of heteroatom‐induced defects conduces to less side‐effects at high working voltages . All these factors compensate the intrinsic disadvantages of unfavorable ion size, poor conductivity and high viscosity in EMIMBF 4 electrolyte . In addition, the low intrinsic Ohmic resistance ( R s , 2.9 Ω) and interfacial charge transfer resistance ( R ct , 0.9 Ω) in Nyquist plots of ALC‐6000‐800 result in an impressively low R ESR of 5.2 Ω (Figure f).…”

“…[16a] All these factors compensate the intrinsic disadvantages of unfavorable ion size, poor conductivity and high viscosity in EMIMBF 4 electrolyte. [43] In addition, the low intrinsic Ohmic resistance (R s , 2.9 Ω) and interfacial charge transfer resistance (R ct , 0.9 Ω) in Nyquist plots of ALC-6000-800 result in an impressively low R ESR of 5.2 Ω (Figure 7f). This result is also smaller than those in reported high-performance EDLCs of ionic liquid electrolytes (8-15 Ω).…”

Recent Advances in Growth and Modification of Graphene‐Based Energy Materials: From Chemical Vapor Deposition to Reduction of Graphene Oxide

“…The CVD‐graphene and rGO deliver apparent disparity when used in supercapacitors, However, Zhang et al prepared 3D nitrogen‐superdoped graphene networks for high capacitive performance by CVD and reduction of graphene oxide method . The N‐superdoped graphene was made up of 3D graphene foams (prepared by CVD) and rGO aerogels with N‐doping level up to 15.8 at%, displaying an enhanced capacitance up to 312 F g −1 under the scan rate of 5 mV s −1 and long‐term operation stability with 93.5% retention of initial capacitance after 4600 cycles.…”

The way to improve the energy density of supercapacitors: Progress and perspective

“…In the posttreatment method, various carbon structures, such as nanofiber [21], metal-organic frameworks (MOFs)/graphene aerogel [22], and graphene foam/reduced graphene oxide [23], can be treated with pyrrole, NH 4 OH, and/or NH 3 to obtain N-doped electrodes. In the in situ preparation method, different N-containing precursors are used to synthesize N-doped carbon materials, including polypyrrole [24], polyacrylonitrile [25], and nitrogen-containing ionic liquids (ILs) [26].…”