Electrodeposited nickel aluminum-layered double hydroxide on Co₃O₄ as binder-free electrode for supercapacitor

Abstract

Here, we report a heterostructured core–shell electrode consists of cobalt oxide (Co₃O₄) nanowire core and nickel aluminum (NiAl)-layered double hydroxide (NiAl-LDH; herein Co₃O₄@LDH) nanosheet shell grown on nickel foam as advanced electrode for supercapacitor. Benefiting from the core–shell configuration and smart hybridization, the optimized Co₃O₄@LDH core–shell electrode exhibits a high capacitance of 2011 F g⁻¹ at 2 A g⁻¹ and remains 1455 F g⁻¹ at 40 A g⁻¹, which outperforms the electrochemical performance of individual component of Co₃O₄ (720 F g⁻¹ at 2 A g⁻¹). A hybrid supercapacitor using Co₃O₄@LDH as positive electrode and carbon nanotube as negative electrode delivers an energy density of 18.1 Wh kg⁻¹ at a power density of 375 kW kg⁻¹ at a current density of 0.5 A g⁻¹. Smart hybridization of core–shell electrode shows great promise as advanced electrode materials for supercapacitor with high electrochemical performance.