Morphology control of Ni3S2 multiple structures and their effect on supercapacitor performances

In this work, the Ni3S2 multiple structures are prepared on Ni foam (Ni3S2@NF) by a mass production one-step hydrothermal method. The prepared Ni3S2@NF multi-structured materials can expose more electroactive sites for fast electron transport owing to their intimate contact with electrolyte. By precisely controlling the proportion of glycerin in the reaction solution, the desired Ni3S2@NF core–shell structure can be synthesized with a high specific capacitance of 736.64 F g−1 at 0.8 A g−1 (7.36 F cm−2 at 8 mA cm−2), which is about one order of magnitude higher than other structures. The role of glycerin for controlling the sample morphology is attributed to its ability to absorb hydrogen sulfide for further reaction to produce nano-sized Ni3S2 structures. The Ni3S2@NF core–shell sample also exhibits good cycling stability of 82% after 1000 cycles. This is because the intertwined nanostructures can accelerate ion transport and protect internal Ni3S2 from degrading. Our work provides a new and efficient mass production method for obtaining energy storage materials with micro-sheet and nano-plated multiple structures.