溶剂热法合成不同形貌的Co3O4及其电容特性

采用溶剂热法以不同的钴盐在水-正丁醇体系中合成了不同形貌及尺寸的纳米Co3O4. 采用XRD和TEM对产物的物相和形貌进行表征. 结果表明, 通过改变反应体系中阴离子的种类, 可以控制产物Co3O4的形貌与晶粒尺寸. 通过循环伏安法、恒流充放电和交流阻抗法对Co3O4电极材料的电化学性能进行表征. 结果表明, Co3O4的形貌与晶粒尺寸对其电化学性能有显著影响. 在2 mol·L-1 KOH溶液中, 在-0.40 - 0.55 V (vs SCE)电位范围内, 由Co(NO3)2制备的球形Co3O4表现出更好的电容特性,单电极初始比容量达362.0 F·g-1, 经过400 次循环后比容量仍保持90%.

Solvothermal Synthesis and Capacitance Performance of Co3O4 with Different Morphologies

Nanostructured Co3O4 with different morphologies was synthesized by solvothermal method using different cobalt salts in water and n-butanol solvent system. The structure and morphology of the products were characterized by X-ray diffraction (XRD) and transmission electronmicroscopy (TEM). The results showed that the shape and size of Co3O4 could be controlled by altering the anions in the reaction system. Electrochemical properties of Co3O4 electrode were characterized by cyclic voltammetry (CV), galvanostatic charge/discharge and alternating current (AC) impedance method. The results indicated that the shape and size of Co3O4 had remarkable influence on its capacitive performance. In the potential range of -0.40-0.55 V(vs SCE), the spherical Co3O4 obtained from cobalt nitrate showed excellent capacitance performance in 2 mol·L -1 KOH electrolyte. The initial specific capacitance of single Co3O4 electrode reached 362.0 F·g-1 and 90% was maintained after 400 cycles.