摘要
采用简单的水热法制备了具有均一八面分子筛(OMSG2)结构的隐甲锰矿型二氧化锰(MnO2);通过水热反应温度控制MnO2的微纳结构,研究反应温度对其超级电容器性能的影响.采用扫描电子显微镜(SEM)、X射线衍射(XRD)和透射电子显微镜(TEM)表征材料的结构特点;采用循环伏安和恒流充放电测试其电化学电容性能.结果表明,制备的MnO2具有纳米刺或纳米棒形成放射状结构,随着反应温度的增加,MnO2晶体逐渐生长完全,从针状纳米刺转变成四方形纳米棒;制备的MnO2具有双电层电容和法拉第准电容的双重特征,在5mA/cm^2的电流密度下,最高比电容达到了603F/g;在100-180℃的范围内,比容量随着反应温度的升高而逐渐降低.
In this article,the uniform cryptomelane-type manganese oxide with an octahedral molecular sieves structure was prepared under mild hydrothermal condition;the effects of hydrothermal temperature on the mi-cro-nanostructure and supercapacitance properties of manganese dioxide were studied in detail.The structures were characterized by SEM,XRD and TEM;and the supercapacitive behaviors were investigated with cyclic voltammetry,galvanostatic charge and discharge tests.The experiment results suggested that:the prepared nanoparticles can be self-organized into dendritic nanostructures,and the nanocluster arrays are composed of nanoneedles or tetragonal prism nanorods;with the increase of reaction temprature,the crystal morphology of manganese oxide was gradually improving,and was trasformed from nanoneedles to tetragonal prism nanorods;the capacitance of MnO2 electrode was a combined contribution of electrical double-layer capacitance and pseud-ocapacitance,and the best specific capacitance value of MnO2 electrode was 603 F/g corresponding to the charge/discharge current density of 5 mA/cm2;with the increase of reaction temperature ranging from 100-180℃,the specific capacitance of manganese oxide gradually decline.
出处
《功能材料》
EI
CAS
CSCD
北大核心
2015年第1期1055-1060,共6页
Journal of Functional Materials
基金
国家自然科学基金资助项目(51203071
51363014
51362018)
教育部重点资助项目(212183)
甘肃省自然科学杰出青年基金资助项目(1111RJDA012)
关键词
超级电容器
MNO2
反应温度
水热法
电极材料
supercapacitor
manganese oxide
reaction temperature
hydrothermal method
electrode material