简单物理混合方法提高MnO2/MnO纳米复合材料的储Zn^2+性能

A simple physical mixing method for MnO2/MnO nanocomposites with superior Zn^2+storage performance

通过简单的物理混合方法制备具有优异储Zn^2+性能的MnO2/MnO正极材料。混合质量比为12:1的MnO2/MnO纳米复合材料具有最高的比容量(0.2C时达364.2 mA·h/g),良好的循环性能(100次循环后达170.4 mA·h/g)和倍率性能(2C时达205.7 mA·h/g)。通过探究储能机理,充放电过程中扩散控制的插入行为和表面电容行为均有助于MnO2/MnO正极的储Zn^2+性能。由于离子扩散的短路径和电子的快速转移,在高放电倍率下,电容行为发挥更大的作用。

MnO2/MnO cathode material with superior Zn^2+storage performance is prepared through a simple physical mixing method.The MnO2/MnO nanocomposite with a mixed mass ratio of 12:1 exhibits the highest specific capacity(364.2 mA·h/g at 0.2C),good cycle performance(170.4 mA·h/g after 100 cycles)and excellent rate performance(205.7 mA·h/g at 2C).Analysis of cyclic voltammetry(CV)data at various scan rates shows that both diffusioncontrolled insertion behavior and surface capacitive behavior contribute to the Zn2+storage performance of MnO2/MnO cathodes.And the capacitive behavior contributes more at high discharge rates,due to the short paths of ion diffusion and the rapid transfer of electrons.