Hierarchical Design of EA ZnCo-LDH/NCS Electrode for Enhanced Electrochemical Performance

Herein, an electrochemically activated zinc–cobalt-layered double hydroxide/nickel–cobalt-sulfide (EA ZnCo-LDH/NCS) hierarchical composite electrode was fabricated in situ via coupled hydrothermal synthesis and electrodeposition. The influence of electrolyte concentration on the activation efficiency was systematically analyzed, and the corresponding effects of electrochemical activation on each component were elucidated. Benefiting from the introduction of the Zn component and subsequent electrochemical activation, the composite electrode exhibits a marked performance enhancement. The EA ZnCo-LDH/NCS electrode achieves a high areal specific capacitance (Cs) of 11.39 F cm−2 at 4 mA cm−2, maintains 70.15% of this value when the current density is increased ten-fold, and retains 80.05% of its initial capacity after 5000 cycles.