Construction of Ni–Mo sulfides core-shell nanoneedle arrays for hybrid supercapacitors with high mass loading

Abstract

In-situ growth technology is a promising strategy to fabricate advanced electrodes for high-performance supercapacitors. However, the active electrode material with low mass loading has prevented its wide applications. Herein, core-shell Ni3S2/MoS2 nanoneedle arrays are grown on a nickel foam by a facile one-step hydrothermal synthesis method. Such Ni3S2 nanowire core - Ni3S2/MoS2 nanosheet shell structure provides appropriate geometries and electronic structures, helping suppress stack tendency at high mass loading and improve the specific capacitance of electrode. Consequently, the optimized Ni3S2/MoS2 (NM-24) electrode achieves a very high areal capacitance of 8.04 F cm−2 at 2 mA cm−2, good rate capability (87.1% of capacitance retention at 15 mA cm−2), and outstanding cycle life in a three-electrode system with high mass loading of 6.3 mg cm−2. Besides, the hybrid supercapacitors device of Ni3S2/MoS2//AC shows a high energy density of 718.88 μW h cm−2 at the power density of 8.5 mW cm−2 and retain 76% after 3000 cycles.