Enhanced energy storage performance of the three-dimensional nickel nitride mesh with mesoporous structure derived from nickel hydroxide nanowires for advanced hybrid supercapacitors

摘要

? 2023 Elsevier LtdNickel nitrides are considered to be promising for hybrid supercapacitors (HSCs) as electrochemical energy storage materials, owing to their good electrical conductivity. However, nickel nitride is prone to agglomeration in high-temperature preparation process, resulting in lower specific surface area and higher porosity, further inhibiting its energy storage performance in HSCs. Consequently, a three-dimensional Ni3N mesh with a mesoporous structure (3D Ni3N Mesh) was constructed as the electrode material for HSCs via a facile hydrothermal reaction and nitrogenization treatment in this work. The as-prepared 3D Ni3N Mesh was built from Ni3N nanoparticles as the bricks that employed the nickel hydroxide nanowires as the precursors. The electrochemical tests demonstrated that the specific capacity of the as-prepared 3D Ni3N mesh could reach 254.2 mAh g?1 at 1 A g?1 in the three-electrode cell. The specific capacity of the 3D Ni3N mesh is still up to 108.3 mAh g?1, even at a high current density of 30 A g?1. The changes of the micro-nano structure, chemical composition and energy storage mechanism of the 3D Ni3N mesh electrode materials in the charge-discharge process were also analyzed and discussed. To further demonstrate its potential applications, a HSCs was also assembled with the 3D Ni3N mesh and the activated carbon (AC) as the positive and negative electrode respectively. It is worth mentioning that the specific capacity of the 3D Ni3N mesh//AC HSCs is 59.3 mAh g?1 at 0.5 A g?1, while the energy density also reaches 56.2 Wh kg?1 at a power density of 468 W kg?1. In addition, the 3D Ni3N Mesh//AC HSCs still maintains 77.4 % capacity along with an average coulombic efficiency of 98.7 % after 5000 continuous cycles, demonstrating good cyclic reversibility.