Optimizing the architecture and tailoring the phase composition are useful approaches to increasing electrochemical capacitor energy storage performance. In this work, a novel three-dimensional (3D) hybrid nickel cobalt sulfide wrapped in ultrathin carbon layer (nickel cobalt sulfides@C) was rationally designed and constructed with varied hollow and porous dendritic superstructures. The morphology evolution process has been demonstrated in detail by adjusting the Co/Ni ratio and reaction duration. Different phases of nickel cobalt sulfides@C can be tailored after sulfuration, enabling the systematic exploration of the energy storage performance with synergistic engineering of architecture and composition. Benefiting from the 3D dendritic superstructures with porous/hollow nature, tunable chemical composition, abundant phase boundaries, enhanced specific surface area, and highly conductive carbon layer matrix, (Ni,Co)9S8/NiS/Ni3S2@C yields an outstanding specific capacity of 856.6 C g-1 at the current density of 1 A g-1. Furthermore, the assembled asymmetric supercapacitor device presents higher energy density of 70.6 Wh kg-1 and power density of 8873.5 W kg-1 with excellent cycling stability. This synthetic strategy highlights the crucial role of synergistic engineering of architecture and chemical composition in practical energy storage, and the as-designed functional materials will be a competitive and promising candidate for robust electrochemical capacitor energy storage and other applications.
- dendritic superstructures
- enhanced energy storage performance
- hybrid nickel cobalt sulfides
- phase evolution
- synergistic engineering