Cao Dianxue

泡沫镍负载的NiCo 2 O 4 纳米线阵列电极的超级电容性能

We prepared an electrode consisting of NiCo2O4 nanowire arrays that stand freely on nickel foam by a template-free growth method.Its morphology was determined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM).The phase structure of the nanowires was analyzed by X-ray diffraction (XRD).The supercapacitance of the electrode was investigated by cyclic voltammetry,galvanostatic charge-discharge testing,and electrochemical impedance spectroscopy.The results showed that the nanowires were nearly vertical grow on and densely cover the nickel foam substrate.The nanowires have diameters around 500-1000 nm and lengths up to around 10 μm.The NiCo2O4 nanowire arrays have a specific capacitance of 741 F · g-1 and this value is 655 F · g-1 after 420 charge-discharge cycles.Electrochemical impedance spectroscopy measurements showed that the charge transfer resistance was only 0.33 Ω and this increased by only 0.06 Ω after 420 cycles.