通过一种简易的制备方法,以三价的氢氧化铁为铁源,乙酸锰为锰源,蔗糖为还原剂和碳源,制备掺锰的磷酸铁锰锂(LiFe0.9Mn0.1PO4/C)复合材料.通过x射线衍射、扫描电子显微镜(SEM)表征掺杂锰对磷酸铁锂的结构和表面形貌的影响,同时通过不同倍率充放电测试、交流阻抗分析、循环伏安法测定等研究LiFe0.9Mn0.1PO4/C电化学特性变化.实验表明:(1)掺杂少量Mn^2+对LiFePO4橄榄石型结构没有明显影响;(2)LiFe0.9Mn0.1PO4/C与纯相的LiFePO4/C相比,具有充放电比容量更大、电化学可逆性更好、结构更稳定、导电性能更优异等优点.
This paper concentrates on the preparation of the LiFe0.9Mn0. 1 PO4/C through a simple method, with the Fe (OH)3 as iron source, the CgH6MnO4·4H2O as manganese source and the C12H22011 as reducing agent and carbon sources. The influence of doped manganese on the structure and morphological performances of the LiFe0.9Mn0. 1PO4/C composites were characterized by X- ray diffraction (XRD) and scanning electron microscopy (SEM). At the same time, we also investigated the change of electrochemical characterization of the LiFe0.9Mn0. 1PO4/C through charge/discharge experiments at different rate, electrochemical impedance spectroscopy (EIS) and cyclic voltammetry. Result shows that: (1) The obvious change of the structure of LiFePO4 olivine-type is not observed with a small amount of doped Mn2+ ; (2) Compared with LiFePO4, the main advantages of the LiFeo.9 Mno. 1 P04/C are larger charging and discharging capacity, better electrochemical reversibility, better structure stability, and more excellent conductivity performance, etc.