CoFe类普鲁士蓝纳米立方的合成及超电容性能

摘要

利用化学共沉淀法,制备CoFe类普鲁士蓝纳米立方(CoFePBA)超级电容器电极材料.利用X射线衍射仪(XRD)和扫描电子显微镜(SEM)对样品进行物理表征;利用循环伏安法(CV)、恒电流充放电法以及交流阻抗法(EIS)对样品的电化学性能进行研究.结果表明:CoFePBA材料为具有面心立方结构的棱长约400 nm的立方颗粒,且表面光滑、颗粒均匀,在氯化钴和铁氰化钾摩尔比为2:1时,产物CoFePBA电化学性能最佳,于中性介质1 mol/L硫酸钠溶液中,在1 A/g电流密度下,比电容能达到444.4 F/g,电流密度增大至5 A/g时,比电容仍能保持在423.1 F/g,2000次充放电循环后,在1 A/g电流密度下比电容保持在439 F/g,容量衰减小于2%.%CoFe Prussian blueanalogue (CoFePBA) nanocubes were prepared by chemical co-precipitation method as electrode materialsfor supercapacitors. Thestructure andmorphology of the CoFePBA materials were characterized by X-ray diffraction (XRD) andscanning electron microscope (SEM). The electrochemical propertieswere investigated by cyclic voltammetry(CV), galvanostatic charge-discharge test and electrochemical impedance spectroscopy(EIS). The results show that the CoFePBA materials withface-centered cubic (FCC)structure are synthesized innanocube morphology with smooth surface anduniform size distribution, and the edge length ofCoFePBA nanocubesis about400 nm.The CoFePBA material prepared with the molarratio of CoCl2 to K3[Fe(CN)6]of2:1 showsthe best electrochemical performance. In the neutral1 mol/LNa2SO4 solution,the as-prepared CoFePBA material exhibitsspecific capacitancesas high as 444.4F/g and 423.1 F/gatthecurrent densityof1A/gand 5A/g, respectively.During the continuous charging and discharging at a current density of 1 A/g, the specificcapacitance remains 439 F/g after 2000 cycles, and the decrease of the capacitance is less than 2%.