Core-shell manganese cobalt oxide‑nickel molybdenum layered double hydroxide composites for supercapacitor electrodes

The electrochemical performance of electrodes for high-energy density supercapacitors is significantly enhanced by using a core-shell composite comprised of layered double hydroxides (LDHs) combined with metal oxides. In this study, a core-shell composite, MnCo₂O₄@NiMo-LDH, was successfully synthesized, characterized, and applied as an electrode. MnCo 2 O 4 was first prepared using calcination and hydrothermal treatment techniques, then MnCo 2 O 4 @NiMo-LDH was prepared using a hydrothermal treatment process. The specific capacitance of MnCo 2 O 4 @NiMo-LDH at 1 A g −1 is 1009 F g −1 . An asymmetric supercapacitor (ASC) assembled using MnCo 2 O 4 @NiMo-LDH electrodes achieved an energy density of 43.2 Wh kg −1 at a power density of 815.8 W kg −1 . Density functional theory (DFT) calculations confirmed that structural and electronic reconstructions occur at the MnCo 2 O 4 @NiMo-LDH interface, enhancing reaction kinetics and improving electrochemical performance. The ASC with MnCo 2 O 4 @NiMo-LDH electrodes exhibited a capacitance retention of 71 % after 5000 cycles, demonstrating excellent long-term cycling stability. The MnCo 2 O 4 @NiMo-LDH electrode exhibits remarkable performance in energy storage applications, highlighting its potential for practical implementation. • A core-shell composite of layered hydroxides and a metal oxide were synthesized. • The MnCo₂O₄@NiMo composite displays excellent electrochemical properties. • MnCo₂O₄@NiMo electrode has enhanced reaction kinetics and charge transfer efficiency. • Supercapacitor with MnCo₂O₄@NiMo anode has excellent long-term cycling stability.