还原剂对Ni(OH)_2/还原氧化石墨烯复合材料结构及电化学性能的影响

为研究还原剂对Ni(OH)_2/还原氧化石墨烯(RGO)复合材料结构及电化学性能的影响,首先以氧化石墨烯(GO)和硝酸镍作前驱体,采用水热法制备了Ni(OH)_2/RGO复合材料;然后,利用XRD、SEM和Raman光谱仪表征了复合材料的结构和形貌,并采用循环伏安法、恒流充放电曲线和电化学阻抗谱研究了复合材料的电化学性能。结果表明:以(NH2)2CSO2作还原剂时,制备的β-Ni(OH)_2/RGO复合材料为RGO纳米片与Ni(OH)_2纳米片相互插层的结构;在电解液(6mol/L KOH溶液)中,0.2C放电倍率时β-Ni(OH)_2/RGO复合材料的比容量高达341.0mAh/g,10.0C放电倍率为时复合材料的比容量为242.2mAh/g,仍能保持β-Ni(OH)_2理论比容量的83.8%。所得结论表明制备的Ni(OH)_2/RGO复合材料显现出良好的电化学性能。

Effects of reductants on structures and electrochemical performances of Ni(OH)2/reduced graphene oxide composites

In order to investigate the effects of reductants on structures and electrochemical performances of Ni(OH)₂/reduced graphene oxide (RGO) composites, Ni(OH)₂/RGO composites were synthesized using graphite oxide (GO) and nickel nitrate as precursors by hydrothermal method firstly. Then, the structures and morphologies of the composites were characterized using XRD, SEM and Raman spectrometer, and the electrochemical performances were investigated using cyclic voltammetry, galvanostatic charge-discharge curves and electrochemical impedance spectroscopy. The results show that when using (NH₂)₂CSO₂ as reductant, the synthesized β-Ni(OH)₂/RGO composite has mutually embedded structure of RGO nanosheets and Ni(OH)₂ nanosheets. The specific capacity of the β-Ni(OH)₂/RGO composite is 341.0 mAh/g in electrolyte (6 mol/L KOH solution) at discharge rate of 0.2C. The specific capacity of the composite is 242.2 mAh/g at discharge rate of 10.0C rate, which still maintains 83.8% of theoretical specific capacity for β-Ni(OH)₂. The conclusions obtained show that the synthesized Ni(OH)₂/RGO composites show excellent electrochemical performances.