纳米K-OMS-5电极材料的制备与电化学性能

在25℃下,以KMnO_4、KOH和MnCl_2为反应物,利用液相氧化还原法制备δ-MnO_2,然后以所制备的δ-MnO_2和KOH为前驱体,在180℃水热下反应2d,合成纳米K-OMS-5(钾-八面体分子筛);分别采用X射线衍射光谱、扫描电镜和热重分析等物理方法对晶体结构、表面形貌及其热稳定性进行表征;用循环伏安、恒流充放电和交流阻抗等电化学方法研究其电化学性能.结果表明,纳米K-OMS-5材料在相同的扫描速率或电流密度下比电容的大小关系为K_2SO_4Na_2SO_4Li_2SO_4,且在0.5mol·L-1 K2SO4电解液中的2 000次循环充放电中展现出了良好的循环稳定性,这或许为K-OMS-5材料在电化学电容器中的应用提供了一种有前景.

Preparation and Electrochemical Performances of Nanostructured K-OMS-5 Intercalation Compounds

In this paper,δ-MnO2 was synthesized with liquid oxidation-reduction method by using KMnO4,KOH and MnCl2 at 25 ℃,and nanostructural K-OMS-5 was prepared by hydrothermal method treated the mixture of δ-MnO2 and KOH at 180 ℃ for 2 day.X-ray diffraction,scanning electron microscopy,thermogravimetric analysis would be used to characterize the crystal structure,morphology,thermal stability of nanostructural K-OMS-5,respectively.The electrochemical performances were investigated by cyclic voltammetry,galvanostatic charge-discharge and electrochemical impedance spectroscopies,etc.The results show that the specific capacitance of K-OMS-5 is in the order of K2SO4 ＞ Na2SO4 ＞ Li2SO4 at same scan rates or current density.K-OMS-5 as the electrode material both exhibits excellent cycling behavior in 2 000 cycles of charge-discharge in 0.5 mol · L-1 K2SO4 electrolyte,which maybe have a promising prospect for application in electrochemical capacitors.