Three dimensional nanonetwork structured Fe-Co-S/Ti3C2@nickel foam integrated electrode for enhanced energy density supercapacitors

Abstract

The rational design of binary transition metal sulfides electrode with boosting capability are attractive for energy storage application. Our work successfully develops an integrated electrode of Fe-Co-S/Ti3C2@NF via the in-situ synthesis of cobalt iron sulfide nanosheets on nickel foam modified by monolayer Ti3C2 high-conductivity scaffolding, forming a three-dimensional interconnected nanonetwork structure. Once applied as a working electrode without any binders, Fe-Co-S/Ti3C2@NF shows a prominent specific capacitance of 1981.6 F∙g−1 at 2 mA∙cm−2 with a better rate performance owe to its well-designed architecture saturating abundant exposed electroactive sites. Moreover, the asymmetric supercapacitor adopting Fe-Co-S/Ti3C2@NF as anode reaches a remarkable electrochemical behavior including a superior energy density of 72.92 Wh∙kg−1 at the power density of 750.0 W∙kg−1 and a minor capacitance decay of 9.7 % after cycling 10 000 charging-discharging. This study offers an efficient method to fabricate advanced integrated supercapacitors electrodes with enhanced energy density.