Three-Dimensional MoS₂Nanodot-Impregnated Nickel Foam Electrodes for High-Performance Supercapacitor Applications

An economical and binder-free electrode was fabricated by impregnation of sub-5 nm MoS2 nanodots (MoS2 NDs) onto a three-dimensional (3D) nickel substrate using the facile dip-coating method. The MoS2 NDs were successfully synthesized by controlled bath sonication of highly crystalline MoS2 nanosheets. The as-fabricated high-surface area electrode demonstrated promising electrochemical properties. It was observed that the as-synthesized NDs outperformed the layered MoS2 peers as the electrode for supercapacitors. MoS2 NDs exhibited an excellent specific capacitance (Csp) of 395 F/g at a current load of 1.5 A/g in a three-electrode configuration. In addition, the fabricated symmetric supercapacitor demonstrated a Csp value of 122 F/g at 1 A/g and a cyclic performance of 86% over 1000 cycles with a gravimetric power and energy density of 10,000 W/kg and 22 W h/kg, respectively. Owing to its simple and efficient fabrication and high surface area, such 3D electrodes show high promise for various energy storage devices.