Controlled synthesis of NiSe-Ni 0.85Se nanocomposites for high-performance hybrid supercapacitors

摘要

Constructing nanostructured multiphase composite is an effective way for optimizing the performance of electrode materials. Here we report our findings in design and fabrication of a high-performance electrode material composed of two-phase nickel selenide (NiSe-Ni0.85Se) nanoparticles, which exhibits a high specific capacity of 669 C g?1at 1 A g?1and 460 C g?1at 20 A g?1, indicating its good rate capability (~69%). Moreover, a hybrid supercapacitor composed of NiSe-Ni0.85Se positive electrode and reduced graphene oxide (rGO) negative electrode delivers a specific capacitance of 101?F?g?1, high energy of 41?Wh?kg?1and good cycling stability with ~80% capacity retention after 5000?cycles at 10 A g?1. These findings provide an important insight into rational design of nanostructured multiphase nickel selenide materials for energy storage systems.