氢氧化钴/氢氧化镍复合材料的制备及电化学性能研究

PREPARATION AND ELECTROCHEMICAL PERFORMANCE OF COBALT HYDROXIDE AND NICKEL HYDROXIDE COMPOSITE MATERIALS

  • 摘要: 过渡金属氧化物(氢氧化物)由于其优良的电容特性而受到极大的关注,其中Co(OH)2和Ni(OH)2是研究的热点。采用电化学沉积法制备不同摩尔比的Co(OH)2/Ni(OH)2复合材料,利用XRD和SEM对沉积产物进行结构和形貌表征,同时采用循环伏安法、恒电流充放电以及电化学阻抗谱对电极材料进行电化学性能测试。结果表明,电化学沉积法可以制备出不同摩尔比的Co(OH)2/Ni(OH)2复合材料,电极材料为纳米花状结构,而这种结构大幅增加了活性材料的比表面积。随着沉积溶液中Co(NO32或Ni(NO32含量的增加,Co(OH)2/Ni(OH)2电极材料的放电时间与比电容值呈现先增大后减小的趋势。其中,当沉积溶液中Ni(NO32:Co(NO32=1:1时,所沉积的Co(OH)2/Ni(OH)2复合材料的放电时间最长、比电容值最大,可达到841.15 F/g。

     

    Abstract: Transition metal oxides(hydroxides) have great concern due to its excellent capacitance characteristics, in which Co(OH)2 and Ni(OH)2 research is a hot spot. Different molar ratios of Co(OH)2/Ni(OH)2 composite materials are prepared by electrochemical deposition, characterization of the morphology and the structure of deposited product is carried out by means of XRD and SEM, electrochemical properties are performed by cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy. The results show that:different molar ratios of Co(OH)2/Ni(OH)2 composite materials can be prepared by electrochemical deposition method, electrode materials possess nano-flower structure, this structure greatly increases the specific surface area of active materials. With increase of Co(NO3)2 or Ni(NO3)2 content in the electrolyte solution, Co(OH)2/Ni(OH)2 electrode materials discharge time and specific capacitance value show a trend of first increase and then decrease. Among them, when Ni(NO3)2:Co(NO3)2=1:1, Co(OH)2/Ni(OH)2 composite material deposited possesses the longest discharge time and the biggest specific capacitance, the specific capacitance value is as high as 841.15 F/g.

     

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