泡沫镍上原位生长CoMn_(2)O_(4)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

Electrochemical performance of hierarchical hollow CoMn_(2)O_(4) hanospheres in-situ grown on nickel foam as supercapacitor electrode materials

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(CoMn_(2)O_(4))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,0.1Co^(2+)-250电极材料在5 mA·cm^(-2)时的面积比电容高达6184 mF·cm^(-2).以0.1Co^(2+)-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10000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,CoMn_(2)O_(4)多级空心纳米球作为电极材料具有重要的应用前景.

Hierarchical hollow nanospheres of cobalt manganese oxide(CoMn_(2)O_(4))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 Co^(2+)-250 electrode material is as high as 6184 mF·cm^(-2)at 5 mA·cm^(-2).The hybrid supercapacitor assembled by 0.1 Co^(2+)-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 10000 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 CoMn_(2)O_(4)electrode material may hold great promise for high-performance supercapacitor applications.