乙二醇和水混合溶剂热法控制合成LiFePO_4及其性能研究

水热法和溶剂热法是合成制备锂离子电池正极材料磷酸铁锂(LiFePO4)最常用的方法,但由于单一溶剂具有的自身缺陷使其在应用方面受到了一定的限制。而水和有机溶剂的混合溶剂热法则是在水/溶剂热法的基础上,充分利用水和有机溶剂各自的理化性质发展起来的有效方法。本文中我们选取乙二醇(EG)和水(H2O)组成二元混合溶剂来控制合成LiFePO4正极材料,并成功地获得了结构形貌规则和颗粒分散均匀的样品材料。然后,通过X射线衍射(XRD)、场发射扫描电子显微镜(FESEM)和电化学性能测试等手段,对获得的样品活性材料进行了表征和测试。结果显示采用混合溶剂热法获得的LiFePO4样品材料具有更好的结构形貌和电化学性能。

Study on Synthesis and Properties of LiFePO4 Controlled by Ethylene Glycol and Water Mixing Solvent Thermal Method

Water and solvent thermal method is the commonly used method for synthesis of lithium-ion batteries cathode material LiFePO4. However, the application and development of single solvent are subjected to some degree of restriction due to their own different weaknesses. The mixed solvent thermal method of water and organic solvent is an effective method based on the water or solvothermal method, which makes full use of their own physicoehemical properties of water and organic solvent. In this paper, we selected water （H2O） and ethylene glycol （EG） which composed of binary mixed solvents in order to control and synthesize LiFePO4 cathode materials. We successfully obtained the sample materials of rule structure and dispersed uniformity. Then, the obtained active materials were characterized and tested by the means of X-ray diffraction （XRD）, field emission scanning electron microscope （FESEM） and electrochemical performance tests The results show that the prepared LiFePO4 samples by the mixed solvent-thermal method, possess better morphology and electrochemical properties than that of materials obtained with hydrothermal method.