A dual NiCo metal-organic frameworks derived NiCo2S4 core-shell nanorod arrays as high-performance electrodes for asymmetric supercapacitors

Abstract

Abstract The structural stability of electrode materials is the crux of significantly improve the electrochemical performance of pseudocapacitor electrodes. Herein, we demonstrate the preparation of NiCo2S4 with core-shell and micro-porous structure on nickel foam as an efficient anode material for asymmetric supercapacitor (ASC) via hydrothermal and co-sulfurization processes. The NiCo2S4 electrode shows a remarkable specific capacitance of 850.2 C g−1 at 1 A g−1, and retains 93.6 % original capacitance after 5000 cycles. Furthermore, the NiCo2S4 electrode also have excellent electrochemical performance when used as an anode of asymmetric NiCo2S4//Active Carbon (AC) supercapacitor, which generates an energy density as 38.1Wh Kg−1 at 700 W kg−1 and 84.3% capacity retention after 5000 cycles. This work provide an efficiently method to suppress volume expansion during sulfuration reaction by core-shell structure, which potential application in transition metal sulfides electrode materials in electrochemical energy storage and conversion devices.