石墨烯对不同形貌钴酸镍结构和电化学性能的影响

石墨烯由于其独特的空间结构和异质性,对金属氧化物的空间结构和结晶性具有非常明显的影响。目前关于石墨烯对钴酸镍(NiCo_2O_4)晶体结构和微观形貌影响的研究较少。通过改变沉淀剂体系,并用十二烷基磺酸钠(SDBS)作为表面活性剂分散石墨烯,用水热反应和煅烧法生成了一维和二维结构的NiCo_2O_4晶体和石墨烯的复合材料。利用SEM、TEM、XRD和氮气吸脱附测试对所制得的复合材料进行微观结构和形貌进行表征,采用恒流充放电、循环伏安和交流阻抗法对复合材料的电化学性能进行了研究。结果表明:石墨烯含量的增加会导致NiCo_2O_4的结晶度下降,但会提高晶体材料的比表面积,对孔隙结构的影响非常明显;石墨烯还能进一步改善复合材料的内阻,但是对电容值的贡献随石墨烯含量的增加先上升后下降。

Influence of Graphene on Nanostructure and Electrochemical Properties of Nickel Cobaltate with Different Morphology

Composites of graphene and NiCo2 04 with 1-D and 2-D structure were made through the hydrothermal and calcination methods by changing the precipitation agent system and using sodium dodecyl sulfonate as surfactant for dispersion of graphene.The micro-structure and morphology of the synthesized composite materials were detected by SEM,TEM,XRD and N2 adsorption-desorption isotherms,and the electrochemical properties of the samples were analyzed by cyclic voltammetry,constant current charge and discharge and AC impedance spectroscopy.Results showed that the increase of graphene could reduce crystallinity of the composite materials and improve the specific surface area of crystal materials,which presented obvious effect on the porous structure.Moreover,graphene could also reduce the resistance of materials,but its attribution to the capacitance value increased and then declined as the content of graphene increased.