关键词: 钴酸镁, ZIF-67, 水热法, 非对称超级电容器, 循环性能, 电化学性能

Abstract: ZIF-67，a metal-organic framework material with a high specific surface area， is one of the ideal precursors for metal oxides. In this paper，ZIF-67 was used as a precursor to prepare nanoflower-like magnesium cobaltate oxide，and its electrochemical properties were tested. The results showed that the specific capacitance of this magnesium cobaltate oxide was 823. 2 F/g at a current density of 1 A/g，which exhibited superior electrochemical properties. After assembling the magnesium cobaltate oxide with activated carbon electrodes to form an asymmetric supercapacitor， the device had a specific capacitance of 78 F/g at a current density of 1 A/g and an energy density of 24. 38 Wh/kg at a power density of 750 W/kg. In addition，the capacitance retention rate was 92. 5% after 5 000 cycles at a current density of 5 A/g.

Key words: magnesium cobaltate oxide, ZIF-67；hydrothermal, asymmetric supercapacitor, cycling performance, electrochemical properties