Construction of hierarchical nickel cobalt sulfide@manganese oxide nanoarrays@nanosheets core-shell electrodes for high-performance electrochemical asymmetric supercapacitor

Core-shell nanostructured three-dimensional binderless electrode porosity makes them ideal candidates for electrochemical energy storage applications. This article proposes NiCo2S4@MnOx electrodes fabricated using a facile hydrothermal approach and subsequently annealed at 120 degrees C for 12 hours. The resultant nanoarrays@nanosheets structure allows rapid ion and electron transport. Coating with pseudocapacitive MnOx on NiCo2S4 nanoarrays improves overall capacitance, and the amorphous MnOx nanosheets promote electrode cycling stability. The proposed NiCo2S4@MnOx electrode achieved excellent specific capacitance of 1640 F center dot g(-1) at 5 mA center dot cm(-2) and cyclic stability approximate to 90%; and the subsequently fabricated asymmetric electrochemical supercapacitor achieved specific capacitance similar to 96.91 F center dot g(-1), and specific energy (SE) 26.38 Wh center dot kg(-1) at specific power (SP) 466.66 W center dot kg(-1), with impressive electrochemical stability approximate to 80% over 5000 charge/discharge cycles.