Constructing nickel sulfide @ nickel boride hybrid nanosheet arrays with crystalline/amorphous interfaces for...

Designing a heterostructure with unique morphology and nanoarchitecture is regarded as an efficient strategy to achieve high-energy-density supercapacitors (SCs). Herein, a rational nickel sulfide @ nickel boride (Ni₉S₈@Ni₂B) heterostructure is in situ synthesized on carbon cloth (CC) substrate via a simple electrodepositon strategy followed by a chemical reduction method. The three-dimensional hierarchically porous Ni₉S₈@Ni₂B nanosheet arrays, consisting of crystalline Ni₉S₈ nanosheets and amorphous Ni₂B nanosheets, can expose ample electroactive centers, shorten ion diffusion distance, and buffer volume changes during charging/discharging process. More importantly, the generation of crystalline/amorphous interfaces in the Ni₉S₈@Ni₂B composite modulates its electrical structure and improves electrical conductivity. Owing to the synergy of Ni₉S₈ and Ni₂B, the as-synthesized Ni₉S₈@Ni₂B electrode acquires a specific capacity of 901.2C g^-1 at 1 A g^-1, a sound rate capability (68.3% at 20 A g^-1), along with good cycling performance (79.7% capacity retention over 5000 cycles). Additionally, the assembled Ni₉S₈@Ni₂B//porous carbon asymmetric supercapacitor (ASC) exhibits a cell voltage of 1.6 V and a maximum energy density of 59.7 Wh kg^-1 at 805.2 W kg^-1. These findings might offer a simple and innovative approach to fabricate advanced electrode materials for high-performance energy storage systems.