氢氧化镍/石墨烯复合材料的制备及其电化学性能研究

Study on the Preparation and Electrochemical Performances of Nickel Hydroxide / Graphene Composites

以石墨粉为原料,硝酸镍为镍源,用化学沉淀-水热法制备Ni(OH)_2/石墨烯复合材料,研究不同氧化石墨(GO)与硝酸镍质量比对复合材料性能的影响,利用XRD、SEM、循环伏安(CV)、交流阻抗(EIS)和恒电流充放电技术测试其结构、表面微观形貌和电化学性质。研究结果表明:当GO∶Ni(NO_3)_2=1∶8(wt.)时,在5 m V/s扫描速度下具有高的活性物质利用率和电化学活性,0.2 C放电比容量可以达到348.5 m Ah/g,显示了优异的大电流充放电性能和循环稳定性。

Nickel hydroxide / graphene composites were prepared using nickel nitrate and graphite powder as raw materials by chemical precipitation-hydrothermal method. The influence of different graphite oxide( GO)-nickel nitrate mass ratios upon the properties of composite materials was then investigated. The prepared samples were characterized by X-ray diffraction, scanning electron microscopy, cyclic voltammetry,AC impedance measurement and galvanostatic charge-discharge cycling technology to evaluate phase structure,surface microstructures and electrochemical characteristics. The results show that the composites exhibit high utilization of active material and electrochemical activity at a scan rate of 5 m V / s; the discharge specific capacity is as high as 348. 5 m Ah / g at 0.2 C discharge rate when the mass ratio of GO to Ni( NO_3)_2 is 1∶ 8. This composite displays an excellent high current charge-discharge performances and cycle stability.