Abstract: Composite materials have become one of the hot topics for supercapacitors′ electrode material because of their abundant active sites and excellent electroconductivity performance. MgCo₂O₄@Co（OH）₂ composite material was successfully synthesized on Ni foam by hydrothermal and electrodeposition in this work. The product was characterized by X-ray diffraction（XRD）and scanning electron microscopy（SEM），and the electrochemical performance of the product was tested by the electrochemical workstation. The results showed that this MgCo₂O₄@Co（OH）₂ composite material exhibited a maximum capacitance of 3 034. 75 F/g at a current density of 1 mA/cm² when used as a binder-free electrode material for electrochemical capacitors. After 1 000 cycles at the current density of 14 mA/cm²，the specific capacitance was maintained at 96%，manifesting the great potential of MgCo₂O₄ as an excellent material for energy storage.

Key words: electrodeposition, MgCo₂O₄@Co（OH）₂composite material；specific capacitance； cycle performance