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

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 to 12000 cycles, indicating that Co0.85Se@NiNP electrode has great application potential in supercapacitors. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

In this study, a novel Co0.85Se@NiNP hybrid electrode was proposed with enhanced specific surface area and efficient ion/electron transport, leading to improved specific capacity, rate performance, and cycle stability in supercapacitors. Furthermore, an asymmetric supercapacitor device was fabricated with Co0.85Se@NiNP//AC electrodes, demonstrating high energy density and outstanding cycle stability, suggesting great application potential in the field of supercapacitors.