Ag-TiO2-MnO2复合材料的制备与电化学性能研究
收稿日期: 2017-11-30
修回日期: 2018-01-09
网络出版日期: 2018-03-12
基金资助
北京市属高校高水平教师队伍建设支持计划(No. IDHT20180504)及17内涵发展-课程和教材建设-优质教学资源立项(No. 310000514117026)资助
Preparation and Electrochemical Performance of Ag-TiO2-MnO2 Composites
Received date: 2017-11-30
Revised date: 2018-01-09
Online published: 2018-03-12
采用高温固相法制备了Ag-TiO2共修饰的二氧化锰锂电池阴极材料,通过X射线衍射仪(XRD)、扫描电子显微镜(SEM)、傅立叶红外光谱仪(FT-IR)、X射线光电子能谱仪(XPS)、能量散射X射线能谱(EDS)、循环伏安测试(CV)、恒流放电测试、交流阻抗测试(EIS)等分别检测了所制备样品的物理-化学特性及相应的电化学性能特征.结果表明:空白二氧化锰与修饰后二氧化锰均为β 晶型,相比于未修饰样品,Ag-TiO2-MnO2 样品的形貌得到了明显的改变.修饰后样品大倍率的放电比容量显著提升,1C 下的容量由 75mAh·g-1 增加到 115mAh·g-1,Ag-TiO2-MnO2 样品 Mn-O 键能的增强对于抑制放电过程中体积膨胀也有一定作用,可以使二氧化锰材料保持较好的结构稳定性.
张伶潇 , 赵惠慧 , 张丽娟 , 付予 . Ag-TiO2-MnO2复合材料的制备与电化学性能研究[J]. 电化学, 2018 , 24(3) : 292 -299 . DOI: 10.13208/j.electrochem.171130
The silver-titanium dioxide co-modified manganese dioxide (Ag-TiO2-MnO2) cathode material was prepared through high temperature solid state reaction. The microstructure, phase composition and electrochemical performance of the prepared samples were characterized by X-ray diffraction spectroscopy (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectrometry (FT-IR), X-ray photoelectron spectroscopy (XPS), Energy-dispersive X-ray spectroscopy (EDS), Cyclic voltammetry (CV), galvanostatic discharge and electrochemical impedance spectroscopy (EIS). Results showed that the unmodified and Ag-TiO2 modified MnO2 samples both exhibited β-MnO2 structurebut with different morphologies. The EDS mapping results revealed that Ag was uniformly dispersed on the surface of manganese dioxide, while Ti was relatively non-uniform in the Ag-TiO2-MnO2 sample. The modified samples were effective in improving specific discharge capacities. The specific discharge capacity increased from 75 mAh·g-1 to 115 mAh·g-1 at the rate of 1C. The stronger bond energy of Mn-O in the modified MnO2 could suppress the volume expansion during the discharge process, which can maintain the structural stability of the manganese dioxide material.