双钙钛矿La2CoNiO6无机纳米纤维的制备及超级电容器性能

摘要

A La2CoNiO6 inorganic nanofiber supercapacitor electrode material was successful y prepared from a polyvinylpyrrolidone/lanthanum nitrate-cobalt acetate-nickel acetate (PVP/LCN) precursor by electrostatic spinning. Its surface morphology and structure were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). We found that the fibers were connected through rhombohedral La2CoNiO6 nanoparticles resulting in a linear spatial network structure. The electrochemical performance of the as-prepared inorganic nanofibers was characterized by cyclic voltammetry (CV), chronopotentiograms (CP), and cycle life tests. The results show that the La2CoNiO6 nanofiber electrode material has good capacitor performance. For the three-electrode system the electrode achieved a respectable specific capacitance of 335.0 F∙g-1 at 0.25 A∙g-1. For the symmetrical two-electrode system the electrode achieved a specific capacitance of 129.1 F∙g-1 at the same current density.%以聚乙烯吡咯烷酮/硝酸镧-乙酸钴-乙酸镍(PVP/LCN)为前驱体,采用静电纺丝法,经预氧化、碳化,制得双钙钛矿La2CoNiO6无机纳米纤维超级电容器电极材料.利用X射线衍射(XRD)、扫描电镜(SEM)和透射电镜(TEM)对其形貌和结构进行表征.结果表明,纤维由菱形结构的La2CoNiO6纳米颗粒相互连接而成,呈链状空间网状结构.循环伏安(CV)、恒流充放电(CP)和循环寿命测试表明, La2CoNiO6纳米纤维电极材料在三电极体系中,电流密度为0.25 A∙g-1时,比电容值达335.0 F∙g-1；在对称型双电极体系中,电流密度为0.25 A∙g-1时,比电容值可达到129.1 F∙g-1,表现出良好的电容性能.