Abstract: Due to their high power，good stability performance，and fast charging and discharging capabilities，supercapacitors （SCs） have attracted much attention in energy storage devices. In this study，we synthesized flower-like MgCo₂O₄@CoMn layer-double hydroxide （LDH） composites by hydrothermal method and electrodeposition. Due to the synergistic interaction between the heterogeneous interfaces of MgCo₂O₄ and CoMn LDH，the electron transport of the composites was improved. In addition，the successful composite of CoMn LDH with low crystallinity provided good hydrophilicity and active sites. In electrochemical tests，the composite material exhibited a high specific capacity of 1 501.8 F/g at a high loading of 4.5 mg/cm². At a current density of 20 A/g，the capacity retention was 82. 98% after 3 000 cycles. It turned out that the composite material demonstrated excellent cycling stability. The resultus show that the MgCo₂O₄@CoMn LDH composite can be used as one of the electrode materials for electrochemical energy storage.

Key words: porous carbon；doped mechanism；heteroatom-doped；adsorption；catalysis；energy-storage