盐酸刻蚀的不同形貌空心结构二氧化锰的电化学行为（英文）

Capacitance Behavior of Manganese Oxide Hollow Structures with Different Morphologies via Hydrochloric Acid Chemical Etching

以液相湿法和水热法合成的碳酸锰为前驱体,通过盐酸的选择性刻蚀分别合成立方体和纺锤体MnO2分级空心结构。采用X射线衍射(XRD)、扫描电镜(SEM)和透射电子显微镜(TEM)对其结构和形貌进行了表征。采用循环伏安、恒流充放电技术和交流阻抗对其电化学性能进行了测试。结果表明,碳酸锰前躯体粒径分布集中,简易快速(3 min)的合成技术所形成的空心结构有利于电解液的渗透,以及电子和离子的传输与交换。在电流密度为0.5 A·g-1时,分级空心立方体MnO2电极比电容为115 F·g-1,并表现出良好的循环稳定性和可逆性。

Hierarchical hollow MnO2 were controllably synthesized by hydrochloric acid chemical etching. MnCO3 with spindle and cube morphology was used as the precursor. The microstructure and morphologies of the resulting materials were characterized by XRD, SEM, TEM and electrochemical measurements. The results indicate that the product obtained by simple reaction for 3 min has hollow structure with excellent permeability,narrow pore-size distribution, and favorable capacitance performance. Further, due to facile mass transfer in the perfectly porous matrix, the synthesized MnO2 show lower equivalent series resistance and better frequency response as revealed from the impedance studies.