A novel electrode for supercapacitors: Spicules-like Ni3S2 shell grown on molybdenum nanoparticles doped nickel foam

In this work, a facile and unique electrode is fabricated by ion implantation and hydrothermal sulfurization methods for the first time. A spicules-like Ni₃S₂ shell is directly grown on the molybdenum nanoparticles doped nickel foam (MoNPs/NF@Ni₃S₂), which exhibits a special hierarchical structure. It is employed as the electrode of supercapacitor, exhibiting good electrochemical performance with high areal capacity of 1.06 C cm^-2 (361 C g^-1) at 1 mA cm^-2, good rate capability, and long cycling life (168% of the initial capacity) for 7000 cycles at 20 mA cm^-2. Compared with Ni₃S₂/NF, the electrode possesses better performance, which is attributed to the doped MoNPs, special morphology of Ni₃S₂, the hierarchical structure, as well as the synergistic effect between Ni₃S₂ and MoNPs. A symmetric supercapacitor based on MoNPs/NF@Ni₃S₂ electrodes maintains 108% of the original capacity after cycling for 7000 cycles at 0.5 mA cm^-2. The results mean that MoNPs/NF@Ni₃S₂ could be used as a battery-type electrode for supercapacitors.