Polypyrrole-wrapped NiCo2S4 nanoneedles as an electrode material for supercapacitor applications

In this study, dicobalt tetrasulfide (NiCo2S4) nanoneedles were successfully synthesized by a two-step hydrothermal method on nickel foam. A layer of polypyrrole (PPy) was further wrapped on the surface of the NiCo2S4 nanoneedles by in-situ polymerization. The obtained NiCo2S4@PPy composite was investigated for supercapacitor applications, which exhibited a capacitance of 1842.8 F g(-1) at 1 A g(-1). An asymmetric supercapacitor device fabricated with an activated carbon negative electrode and NiCo2S4@PPy positive electrodes exhibited an energy density of 41.2 Wh kg(-1) at 402.2 W kg(-1) with a high charge-discharge cycling stability (92.8% after 5000 cycles). These results demonstrate that NiCo2S4@PPy electrodes have broad application prospects as energy storage electrode materials.

Automated summary

NiCo2S4 nanoneedles were successfully synthesized by a two-step hydrothermal method and further coated with a layer of PPy through in-situ polymerization to form NiCo2S4@PPy composite. The NiCo2S4@PPy electrodes exhibited high capacitance and excellent cycling stability, indicating great potential for energy storage electrode materials.