Self-Supported NiSe/Ni Foam: An Efficient 3D Electrode for High-Performance Supercapacitors

Three-dimensional (3D) mixed phases NiSe nanoparticles growing on the nickel foam were synthesized via a simple one-step hydrothermal method. A series of experiments were carried out to control the morphology by adjusting the amount of selenium in the synthetic reaction. Meanwhile, the as-prepared novel column-acicular structure NiSe exist three advantages including ideal electrical conductivity, high specific capacity and high cycling stability. It delivered a high capacitance of 10.8 F cm(-2) at a current density- of 5 mA cm(-2). An electrochemical capacitor device operating at 1.6 V was then constructed using NiSe/NF and activated carbon (AC) as positive and negative electrodes. Moreover, the device showed high energy density of 31 W h kg(-1) at a power density of 0.81 kW kg(-1), as well as good cycling stability (77% retention after 1500 cycles).