Design and Synthesis of N-Doped Carbon Skeleton Assembled by Carbon Nanotubes and Graphene as a High-Performance Electrode Material for Supercapacitors

Abstract

Current, there is an urgent demand for electrode materials with superior electrochemical performances for the development of supercapacitors. A nitrogen-doped carbon skeleton (NCS) assembled by carbon nanotubes and graphene layers is designed and synthesized utilizing a layer-shaped humate-based zeolitic imidazolate framework (ZIF) (HA-CoFe-ZIF) as a template in this work. The synthesized NCS is mainly composed of graphitized carbon with a few hydroxyl groups on its surface, synchronously doped by 9.5 at % nitrogen in the state of pyridinic N and pyrrolic N. The rich mesoporous structure entitles it to a high Brunauer–Emmett–Teller (BET) specific surface area of 427 m2 g–1 and suitable BET average pore diameter of 3.14 nm. The NCS has a high capacity of 324 F g–1 at 1 A g–1, good rate capability (capacitance retention of 71% from 5 to 100 A g–1), and excellent cycling stability (capacitance retention of 96 and 87% after 5000 and 10 000 cycles, respectively). The fabricated NCS//AC asymmetric supercapacitor also exhibits a high capacity of 93 F g–1 at 1 A g–1, large energy density of 10.3 Wh kg–1 at 331 W kg–1, and good cycling performance (capacitance retention of 88% after 5000 cycles). Our elaborately designed NCS materials exhibit multiple structural advantages including rich mesoporous structure, various graphitic carbon, and high-dosage nitrogen doping, resulting in high capacitance performances. This humate-based metal–organic framework (MOF)-derived strategy provides a good idea for the synthesis of high-performance carbon skeleton materials applied to energy storage.

Controlling Morphologies and Structures of PANI@Carbon with Superior Rate Performance for Supercapacitors

“…Figure c displays the specific capacitances of NNPC and many other reported carbon materials for supercapacitors under different current densities (1–100 A g –1 ), revealing the strongest charge storage capacity even at a large current. Figure d clearly shows the specific capacitance retention of NNPC when the current densities increase from 1 to 10 and 100 A g –1 , delivering admirable rate performances with even 78.3% capacitance retention at 100 A g –1 and outweighing those reported carbon-based electrode materials, ,− such as conductive Cu-MOF with an array architecture on carbon paper, N-doped PC composite derived from crop waste and polypyrrole with a cross-linked network structure, PC derived from transgenic poplar, and a carbon electrode from hexahedral Zn-BTC . Some of the carbon materials reported in the literature display more than 70% capacitance retention from 1 to 10 or 100 A g –1 , but disappointingly, they perform with lower specific capacity.…”

CoFe2O4 Nanoparticle Decorated Hierarchical Biomass Derived Porous Carbon Based Nanocomposites for High-Performance All-Solid-State Flexible Asymmetric Supercapacitor Devices

“…CV profiles of this device obtained at various bending angles were almost similar to each other (Figure d) which indicates the mechanical robustness and good flexibility of the fabricated device. The fabricated flexible device showed an energy density of 50.34 W h kg –1 at a power density of 1450 W kg –1 , which is equivalent and in some cases superior to that of some of the reported carbon-based ASC (Table S2) ,,,,− ,− and commercially available supercapacitors (3–9 W h kg –1 at 3000–10000 W kg –1 ). , The Ragone plot obtained from these values at numerous current densities is presented in Figure e. Illumination of 16 light-emitting diodes (LEDs) is shown in Figure f when four devices are connected in series.…”

A high-performance flexible energy storage device from biomass-derived porous carbon supported MnCo2O4 nanorods and MnO2 nanoscales

“…8c (Table S2†). 1,5,15,20,21,36,53–66 The device exhibited a high energy density value of 81.3 W h kg −1 at a power density of 1600 W kg −1 and 37.3 W h kg −1 even at a high power density of 9600 W kg −1 . A panel of a total of 65 LEDs was lighted by connecting four fabricated devices in order to demonstrate its lab-scale practical utility (Fig.…”