碳酸锰纳米片阵列的制备及其电化学性能研究

Preparation and electrochemical properties of manganese carbonate nanoplate arrays

为了提高以锰基材料做正极的水系锌离子电池的工作电压,通过溶剂热法一步实现超薄MnCO_(3)纳米片阵列(NA)在泡沫镍基底上的生长,并采用X射线衍射(XRD)、扫描电子显微镜、透射电子显微镜、电池性能测试仪等对其结构、形貌和电化学性能进行了表征。结果表明,该MnCO_(3)纳米片厚度约为30 nm,高度约为500 nm;将该MnCO_(3) NA直接应用于锌离子电池,在碱性电解液体系中,展现出1.73 V的高工作电压,在0.1 A/g的电流密度下放电比容量达到255.41 mAh/g,且在0.5 A/g的电流密度下进行270次充放电循环后,容量保持率约为83.1%。基于不同电位状态下的非原位XRD和光电子能谱XPS测试表明,该电极的储锌机制为Mn^(2+)转变为Mn^(3+)的单相反应。

In order to increase the working voltage of the aqueous zinc ion batteries with manganese-based material as the positive electrode material,an ultrathin nanosheet array(MnCO_(3) NA)was grown on a nickel foam substrate by a one-step solvothermal method.The structure,morphology and electrochemical properties of MnCO_(3) NA were characterized by X-ray diffraction(XRD),scanning electron microscope,transmission electron microscope and battery performance tester.The experiments results showed that the thickness of the MnCO_(3) NA was about 30 nm and the height was about 500 nm.It was directly applied to the zinc ion battery in the alkaline electrolyte,delivering a high working voltage of 1.73 V,a specific discharge capacity of 255.41 mAh/g at 0.1 A/g,and a capacity retention of 83.1%after 270 charge-discharge cycles at 0.5 A/g.In addition,the zinc storage mechanism of the electrode was a mono-phase reaction from Mn^(2+)to Mn^(3+),which was analyzed by ex-situ XRD and photoelectron spectroscopy at different potential states.