Tailoring Mo-Doped NiCoP Grown on (Ni,Co)Se2 Nanoarrays for Asymmetric Supercapacitor with Enhanced Electrochemical Performance

Both composition and nanostructure play vital roles in the electrochemical properties of the transition-metal compounds. Rational elemental doping and nanostructure design could accelerate the Faradaic redox reaction kinetics and increase the electroactive sites. Herein, we have successfully synthesized core-shell structure nanoarrays where (Ni,Co)Se-2 nanowires directly grow on activated carbon cloth as the conductive core to support an Mo-doped NiCoP nanosheet shell. This hierarchical nanoarray electrode exhibits a high areal capacity of 1.99 C/cm(2) at 2 mA/cm(2) (a gravimetric specific capacity of 797 C/g) and notable rate capability (1.54 C/cm(2) at 50 mA/cm(2)). The asymmetric supercapacitor device assembled using (Ni,Co)Se-2@Mo-NiCoP as the cathode and activated carbon as the anode exhibits a high energy density of 33.7 Wh/kg at a power density of 800 W/kg.

Automated summary

Both composition and nanostructure are crucial for the electrochemical properties of transition-metal compounds. Rational elemental doping and nanostructure design can enhance Faradaic redox reaction kinetics and increase electroactive sites. In this study, a hierarchical core-shell nanoarray electrode was successfully synthesized, demonstrating high areal capacity and notable rate capability, with an asymmetric supercapacitor device achieving a high energy density at a specific power density.