One-Pot Template-Free Strategy toward 3D Hierarchical Porous Nitrogen-Doped Carbon Framework in Situ Armored Homogeneous NiO Nanoparticles for High-Performance Asymmetric Supercapacitors

Abstract

The composites based on graphitic carbon and transitional metal oxides are regarded as one of the most promising electrochemical materials owing to the synergistic combination of the advantages of both superior electrical conductivity and high pseudocapacitance. In this work, a simple one-pot template-free strategy for the preparation of three-dimensional hierarchical porous nitrogen-doped carbon framework in situ armored NiO nanograins (NCF/NiO) by an ammonia-induced method assisted by the pyrolysis of a decomposable salt is reported. Due to such unique architecture and homogeneously dispersed nanoparticles, the as-prepared NCF/NiO-2 hybrid exhibits a large specific surface area (412.3 m g), a high specific capacitance (1074 F g at 1 A g), good rate capability (820 F g at 20 A g), and outstanding cycling performance (almost no decay after 5000 cycles). Moreover, the solid-state asymmetric supercapacitor, assembled with NCF/NiO-2 and NCS electrodes, can achieve a high cell potential of 1.6 V and deliver a superior specific capacitance of 113 F g at 1 A g with a maximum energy density of 40.18 W h kg at a power density of 800 W kg, consequently, giving rise to stable cycling performance (94.3% retention over 5000 cycles). The prepared devices are shown to power 20 green light-emitting diodes efficiently. These encouraging results open up a wide horizon for developing novel carbon-supported metal oxide electrode materials for high rate energy conversion and storage devices.

Conductive NiMn-based bimetallic metal–organic gel nanosheets for supercapacitors

“…The electrode material specific capacitance C m (F g -1 ) is calculated according to equations (1), respectively. 27,28 V m…”

“…The preparation methods of the electrodes NiMn MOG//AC and AC are similar to the above. The mass ratio of NiMn MOG (positive electrode material) and AC (negative electrode material) is balanced according to the following equation: 27,28…”

Application of Biomass‐Derived Nitrogen‐Doped Carbon Aerogels in Electrocatalysis and Supercapacitors

“…The 3D hierarchical porous structure was engendered by direct pyrolysis under N 2 atmosphere, lacking the aid of supplementary activation agents. Pretreating the chitosan hydrogel with ammonia provoked the formation of multiscale pores in the hydrogel and the basic environment also enhanced the formation of the metal nanoparticles . Three different samples with varying amounts of Ni (Ac) 2 ⋅4H 2 O were prepared and labelled as NCF/NiO‐1 (0.25 g), NCF/NiO‐2 (0.5 g) and NCS (0 g).…”

Nitrogen- and Oxygen-Containing Three-Dimensional Hierarchical Porous Graphitic Carbon for Advanced Supercapacitor

“…However, there still exist several disadvantages for carbon-based materials, such as the sluggish ion diffusion and low electrical conductivity [15][16][17]. Sluggish ion diffusion may cause capacity loss and low power density during the fast charging/discharging process [18].…”