Amorphous Hollow NiCo(OH) _<i>x</i> S _<i>y</i> Spheres with Improved Electrochemical Performance for Supercapacitor Applications

Supercapacitors demonstrate substantial application prospects in the energy storage domain owing to their high power density, swift charging-discharging capabilities, and prolonged cycle life. However, their relatively low energy density constrains their further advancement. In this study, a double-ligand NiCo(OH)_<i>x</i>S_<i>y</i> amorphous material with a hollow bulbous morphology was effectively fabricated using a homemade self-sacrificing precursor template. Due to the distinctive amorphous structure and the OH/S dual-ligand synergistic effect, the electrode material exhibited excellent charge storage performance (1912 F g^-1 at 1 A g^-1 and 79.1% retention at 20 A g^-1). The asymmetric supercapacitor (NiCo(OH)_<i>x</i>S_<i>y</i>//PC) achieves a value of 60.97 Wh kg^-1 at 375 W kg^-1. After 8000 charge-discharge cycles at 5 A g^-1, it showed 88.5% capacity retention and 99.6% Coulombic efficiency. These outstanding electrochemical performances suggest the considerable potential of NiCo(OH)_<i>x</i>S_<i>y</i> in energy storage devices.