关键词: 超级电容器, 石墨, 溶胶凝胶法, NiO包覆, 电化学性能

Abstract: Carbon-based electrode materials and transition metal oxide materials have their properties as the common electrode materials for supercapacitors. In this paper，graphite was used as the matrix，and metal nickel oxide was coated on the graphite surface with a sol- gel method to form a new capacitor electrode composite. The structure and electrochemical properties of graphite and graphite coated with nickel oxide were characterized by N2 adsorption- desorption analyzer， X- ray diffractometer，electrochemical workstation，and charging and discharging tester. The experimental results showed that the nickel oxide coating could effectively improve the microstructure and electrochemical properties of the graphite matrix. The specific surface area of the material significantly increased， and the pore volume also increased. The nickel oxide coating exhibited obvious characteristics of tantalum capacitance. In the first discharge，the specific capacity of graphite coated with nickel oxide at the current density of 0. 2 A/g was 203. 13 F/g . At the current density of 5 A/g，the discharging specific capacity of graphite coated with nickel oxide was 130. 45 F/g，and graphite was only 90. 02 F/g，and the specific capacity of graphite after nickel oxide coating increased by 45%. There is a synergistic effect between the graphite and nickel oxide coating，and the nickel oxide coating can reduce the impedance of the graphite and improve the cycle performance.

Key words: supercapacitors, graphite, sol-gel method, nickel oxide coating, electrochemical properties