锂离子电池负极材料a-Fe_2O_3的水热合成与性能研究

Hydrothermal synthesis and electrochemical properties of a-Fe_2O_3 as anode materials for lithium-ion batteries

用水热反应法合成了几种具有不同形貌的低维纳米结构的α-Fe2O3材料。通过X射线衍射和透射电镜等测试手段对材料微观结构和形貌做了表征。分析探讨了不同沉淀剂和沉淀剂浓度对产物形成机理的影响,表活剂的存在对材料微观形貌的影响,以及微乳液体系在水热合成中的尝试应用等问题。将合成的α-Fe2O3材料组装成模拟电池进行恒电流充放电测试,考察了其作为锂离子电池负极材料的电化学性能。结果证明,随着材料微观形貌和粒径的改变,其电化学性能也有明显的差异。部分合成材料具有较好的电化学性能,具有较大的放电比容量和稳定的循环充放电性能。

Several low-dimensional nanostructure α-Fe2O3 materials with different micromorphologies were synthe-sized by hydrothermal methods.The crystalline structure and morphology of the as-synthesized powder was charac-terized by X-ray powder diffraction（XRD） and transmission electron microscopy（TEM）.Some problems were sys-tematically discussed,such as the effect of the variety and concentration of the precipitators on formative mechanism of the materials,the effect of the surfactant on morphology of the particles,and the attempt of microemulsion system in hydrothermal method.The electrochemical properties of α-Fe2O3 as anode materials for lithium-ion batteries were investigated by galvanostatic charge-discharge tests.And the results indicate that the changes of morphology and particle size have great effect on the electrochemical properties of the samples.The prepared rod-like α-Fe2O3 has a larger discharge capacity and better cycle performance.