摘要
Li2SiO3 was synthesized by combination of sol-gel method and calcination at high temperature using Li2CO3, HNO3, Si（OC2H5）4 and C2H5OH as starting materials. The effects of calcination temperature and refluxing system on the composition and properties of lithium silicate were investigated. The samples were characterized by TGA/DTA, XRD, SEM and particle size analysis. Li2FeSiO4 was prepared by the solid-state reaction between Li2SiO3 and FeC2O4·2H2O. The XRD patterns show that the use of refluxing system in the sol-gel preparation can decrease the Li2Si2O5 and Li4SiO4 impurities in the Li2SiO3 sample. The calcination temperature plays an important role in the properties of the Li2SiO3 samples. The sample calcined at 700 °C has high purity of 97% Li2SiO3 and good morphology as precursor of Li2FeSiO4. It consists of primary particles with size of 1-3 μm, and the primary particle clusters form agglomerates with loose and porous appearance.
以Li2CO3,HNO3,Si(OC2H5)4为原材料,采用溶胶-凝胶和高温焙烧法合成Li2SiO3;研究焙烧温度和回流系统对硅酸锂组分和性能的影响;利用TGA/DTA,XRD,SEM和粒径分析等手段对样品进行表征;采用Li2SiO3和Fe2C2O4.2H2O固相反应制备Li2FeSiO4。XRD结果表明,在溶胶-凝胶制备过程中使用回流系统能减少Li2SiO3样品中Li2SiO5和Li4SiO4杂质。焙烧结温度对Li2SiO3的性能有重要的作用,当温度为700℃时,Li2SiO3前驱体材料样品纯度为97%,并具有良好的形貌;它是由粒径为1～3μm的一次粒子组成,一次粒子束形成疏松、多孔的团聚体。
基金
Foundation item: Project (2007CB613607) support by the National Basic Research Program of China
Project (2010QZZD0101) supported by the Basic Research Foundation for the Chinese Central Universities
