Co_3O_4纳米线的丙三醇辅助合成及其电化学性质(英文)

Glycerol-Assisted Synthesis and Electrochemical Properties of Co_3O_4 Nanowires

以硝酸钴和丙三醇为反应物通过反应条件的改变控制制备出Co3O4纳米线.利用粉末X射线衍射(XRD),扫描电子显微镜(SEM)和透射电子显微镜(TEM)对产物的形貌与结构进行了表征.实验发现,在低扫描速率下,Co3O4纳米线电极的循环伏安(CV)曲线呈现出两对氧化还原峰.恒电流充放电实验中,氧化钴纳米线电极在1A.g-1电流密度下的电容为163F.g-1;在1和4A.g-1条件下,其容量随循环次数的增加先上升后下降,1000次充放电循环后容量保持率分别在98%和80%以上,继续增加循环次数则容量下降比较明显.锂离子电池性质测试中,氧化钴纳米线的放电容量为1124mAh.g-1,然而放电容量随循环次数增加下降较快.基于实验结果,对Co3O4纳米线的形成机理及其结构与电化学性质之间的关系进行了探讨.

Cobalt oxide （Co3O4） nanowires were controllably synthesized using glycerol and Co（NO3）2 as reagents and adjustment of the experimental parameters. The morphology and structure of the asprepared products were characterized by a series of techniques such as X-ray podwer diffraction （XRD）, scanning electron microscopy （SEM）, and transmission electron microscopy （TEM）. Electrochemical performance of the nanowires was studied by cyclic voltammetry （CV） and galvanostatic charge-discharge measurements. It was found that two pairs of redox peaks appeared in the CV curves of C0304 nanowire electrodes at low scan rates. The specific capacitance of the Co3O4 nanowire electrodes was 163 F.g-1 at a current density of 1 A. g-1, according to the galvanostatic charge-discharge measurements. Cycle stability tests showed that the specific capacitance increased over the first tens of cycles and then reduced slowly. After 1000 cycles, the capacitance retention was over 98% at 1 A.g-1 and 80% at 4 A. g-1; it then decreased obviously with further increase in cycle number. In Li-ion battery measurements, Co3O4 nanowire electrodes showed a discharge capacitance of 1124 mAh. g-1 which decreased rapidly during the cycle test. The formation mechanism and the relationship between the structure and electrochemical properties of Co3O4 nanowires were discussed based on the experimental results.