泡沫镍上原位生长CoMn2O4多级空心纳米球作为超级电容器电极材料的电化学性能研究

采用水热法结合空气气氛中的热处理过程，在泡沫镍（NF）表面生长了锰酸钴（CoMn₂O₄）多级空心纳米球，通过X射线衍射仪（XRD）、场发射扫描电镜（FE-SEM）和X射线光电子能谱（XPS）等测试手段对纳米球进行了表征.在三电极电化学测量系统中，0.1Co²⁺-250电极材料在5 mA·cm^-2时的面积比电容高达6 184 mF·cm^-2.以0.1Co²⁺-250为正极，商用活性炭（AC）为负极组装而成的混合超级电容器，在1.6 mW·cm^-2时的最大能量密度为0.112 mWh·cm^-2.即使在功率密度为16 mW·cm^-2时，能量密度仍达到0.064 mWh·cm^-2.在2 mA·cm^-2的电流密度下，经过10 000次充放电循环后，电容保持了初始值的93%.因其优越的电化学性能和低成本的便捷合成方法，CoMn₂O₄多级空心纳米球作为电极材料具有重要的应用前景.

Electrochemical performance of hierarchical hollow CoMn2O4 hanospheres in-situ grown on nickel foam as supercapacitor electrode materials

Hierarchical hollow nanospheres of cobalt manganese oxide(CoMn₂O₄) on nickel foam(NF) are facilely synthesized by a hydrothermal method and post heat treatment in air, and further characterized by diffraction of X-rays(XRD), field emission scanning electron microscope (FE-SEM) and X-ray photoelectron spectroscopy(XPS). In a three-electrode system of electrochemical measurement, the areal capacitance of 0.1 Co²⁺-250 electrode material is as high as 6 184 mF·cm^-2 at 5 mA·cm^-2. The hybrid supercapacitor assembled by 0.1 Co²⁺-250 as the positive electrode and commercial activated carbon (AC) as negative electrode presents a maximum energy density of 0.112 mWh·cm^-2 at 1.6 mW·cm^-2. Even at the power density of 16 mW cm^-2, the energy density still reaches 0.064 mWh·cm^-2. After 10 000 charge/discharge cycles under the current density of 2 mA·cm^-2, the capacitance retains 93% of the initial value. With excellent electrochemical performance and facilely cost-effective synthesis, such hierarchical CoMn₂O₄ electrode material may hold great promise for high-performance supercapacitor applications.