Construction of Co0.85Se@nickel nanopores array hybrid electrode for high-performance asymmetric supercapacitors

Abstract Nanostructured current collectors have larger specific surface area and short ion/electron transport path, which are highly desirable for supercapacitors applications. Herein, Co0.85Se@NiNPs (Co0.85Se@NiNP) hybrid electrodes are proposed and fabricated, in which NiNP is served as nanostructured current collectors. NiNP has a vertical pore structure and a large specific surface area, which could effectively promote the ion/electron transport efficiency and reduce internal electrical resistance. Compared with Ni foam and Ni foil as current collectors, NiNP enables Co0.85Se@NiNP electrodes show significantly improved specific capacity, rate performance and cycle stability. Finally, an asymmetric supercapacitor device was assembled with Co0.85Se@NiNP hybrid electrode as the binder-free positive electrode and activated carbon (AC) coated on nickel foam as negative electrode. The Co0.85Se@NiNP//AC asymmetric supercapacitors can work in a wide potential window of 0 – 1.6 V with an ultrahigh specific capacity of 182.3 F g-1 at 1 A g-1. Most importantly, Co0.85Se@NiNP//AC has a high energy density of 64.81 Wh kg-1 at 800 W kg-1 and an outstanding cycle stability of up to12000 cycles, indicating that Co0.85Se@NiNP electrode has great application potential in supercapacitors.