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

Abstract

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[Formula: see text]F[Formula: see text]cm[Formula: see text] at a current density[Formula: see text] of 5[Formula: see text]mA[Formula: see text]cm[Formula: see text]. An electrochemical capacitor device operating at 1.6[Formula: see text]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[Formula: see text]W[Formula: see text]h[Formula: see text]kg[Formula: see text] at a power density of 0.81[Formula: see text]kW[Formula: see text]kg[Formula: see text], as well as good cycling stability (77% retention after 1500 cycles).