A novel electrode for supercapacitors: efficient PVP-assisted synthesis of NiS nanostructures grown on Ni foam for energy storage.

In this academic research, we report the polyvinylpyrrolidone (PVP) assisted synthesis of a Ni3S2 electrode material containing a plentiful number of active sites on Ni foam by a novel hydrothermal approach. Interestingly, the Ni3S2 electrode is a highly efficient electroactive material, as evidenced by the physical and electrochemical characterization. Based on the physical characterization, the constructed Ni3S2 nano architecture exhibited plentiful electroactive sites, quick charge/discharge transportation and better maximum conductivity, which gave rise to enhanced electrochemical activity for large-scale supercapacitors (SCs). Besides, the electrochemical characterization of the as-developed Ni3S2 electrode obviously displayed a faradaic battery-based redox profile, which is distinct from the profiles of carbon-type materials. The battery-based PVP-assisted Ni3S2 electrode achieved impressive electrochemical activity, namely exceptional SC activity with a superior specific capacity of ∼316.8 mA h g-1 at 2 A g-1 current density, high rate capability with ∼91.4% of capacity retained at 20 A g-1, and superb cycling performance with ∼96.7% of capacity retained at 6 A g-1 after 4000 cycles. Thus, considering the best findings above, the as-developed PVP-assisted Ni3S2 is a highly efficient candidate for SCs and could effectively serve in various advanced energy storage applications.