In situ self-sacrificed template synthesis of vanadium nitride/nitrogen-doped graphene nanocomposites for electrochemical capacitors

Abstract

Vanadium nitride and graphene have been widely used as pseudo-capacitive and electric double-layer capacitor electrode materials for electrochemical capacitors, respectively. However, the poor cycling stability of vanadium nitride and the low capacitance of graphene impeded their practical applications. Herein, we demonstrated an in situ self-sacrificed template method for the synthesis of vanadium nitride/nitrogen-doped graphene (VN/NGr) nanocomposites by the pyrolysis of a mixture of dicyandiamide, glucose, and NHVO. Vanadium nitride nanoparticles of the size in the range of 2 to 7 nm were uniformly embedded into the nitrogen-doped graphene skeleton. Furthermore, the VN/NGr nanocomposites with a high specific surface area and pore volume showed a high specific capacitance of 255 F g at 10 mV s, and an excellent cycling stability (94% capacitance retention after 2000 cycles). The excellent capacitive properties were ascribed to the excellent conductivity of nitrogen-doped graphene, high surface area, high pore volume, and the synergistic effect between vanadium nitride and nitrogen-doped graphene.

An Eco‐Friendly Nitrogen Source for the Preparation of Vanadium Nitride/Nitrogen‐Doped Carbon Nanocomposites for Supercapacitors

“…In Figure 5b, the specific capacitance valves of 0.06-VN/NCS2, 0.04-VN/NCS2, 0.03-VN/NCS2, NCS2 and commercial VN electrodes calculated from the GCD curves at a current density of 1 A g À 1 were 137 F g À 1 , 299 F g À 1 , 187 F g À 1 , 28 F g À 1 and 16 F g À 1 , respectively, which was agreed with the results of the CV curves. It should be noted that the specific capacitance of the 0.04-VN/NCS2 electrode is much higher than those of the reported vanadium nitride or carbon-based electrodes [5,23,24,31,36,43,45,46] (see Table 1).…”

“…The peaks at 530.0 eV, 531.1 eV and 532.2 eV in the O 1s XPS spectrum originated from VÀ O, VÀ O-N and OÀ C=O, respectively, and the presence of VÀ O, VÀ OÀ N was ascribed to the vanadium oxides on the surface of VN NPs . [5] In addition, the XPS spectrum of V 2p could be divided into three peaks at about 513.9 eV, 515.2 eV and 516.9 eV, corresponding to VÀ N, VÀ NÀ O as well as VÀ O, respectively. [39,40] These results disclosed the presence of VN, NC and a few VO x in the nanocomposite.…”

“…[2,3] Nevertheless, the low energy density of SCs impedes their practical applications. [4] As the electrochemical behaviors of SCs are primarily governed by the electrode materials used, [5] it is highly desirable to develop a novel electrode material with prominent electrochemical behavior. It is well known that SCs can be categorized into pseudocapacitors (PCs) based on the redox reaction mechanism and electrical double-layer capacitors (EDLCs) based on the reversible ion adsorption-desorption at the electrode-electrolyte interface.…”

Fabrication of a vanadium nitride/N-doped carbon hollow nanosphere composite as an efficient electrode material for asymmetric supercapacitors

“…[1][2][3] Supercapacitors (SCs) have been propelled to the forefront of the eld of energy storage due to their considerable merits, such as their high power densities, long cycle lives, fast recharging capabilities, and environmental benignness. [4][5][6] Nevertheless, the low energy density of SCs severely hinders the commercialization process. 7,8 Therefore, an effective strategy to enhance the energy density while ensuring the power density of SCs is urgently needed.…”

Microstructure and electrochemical performance of 3D hierarchical porous graphene/polyaniline composites

“…5 Porous graphene materials show outstanding performance in the energy storage eld due to their unique microstructure and properties. [6][7][8] The pore size, pore shape, and pore volume of the porous graphene material are critical to the performance. Therefore, it is of great research signicance to build a unique porous structure of graphene in order to improve its application value in various high performance devices.…”