工艺因素对固相反应制备LiMPO_4的影响

Influence of Process Factors on Synthesis of LiMPO_4 via Solid State Reaction

以氢氧化锂、磷酸二氢铵和醋酸盐(醋酸锰、醋酸钴、醋酸镍)为原料,在PEG-400表面活性剂诱导下,低热固相反应数小时,得到前驱体,再在较高温度下前驱体反应得到含锂磷酸盐LiMPO4(M=Mn,Co,Ni)。实验以XRD图谱拟合数据计算样品中含锂磷酸盐的质量分数作为实验的考察指标,应用均匀设计实验法及数据挖掘技术研究了各工艺因素对考察指标的动态影响,探讨制备的最优化工艺因素和杂质的定量控制方法,并对最优化工艺因素制备的样品进行XRD、SEM-EDAX等表征。结果表明:工艺因素之间能互为表达,部分因素对考察指标存在交叉作用,低温合成前驱体工艺取值范围可较大,但高温反应合成LiMPO4工艺取值范围较小,特别是固相反应温度和时间的取值直接影响产物的性质。

With lithium orthophosphates as electrode material of lithium batteries,magnetoelectric crystals was studied,and the products was got successfully after baking the precursor at high temperature,the precursor was prepared with lithium hydroxide,monoammonium phosphate,acetate（manganese acetate,cobalt acetate or nickel acetate）as start materials and PEG-400 as surfactant via low heat sate reaction at 60-100 ℃.The mass fraction of lithium orthophosphates calculated with XRD data of the products was used as a testing index.The uniform experimental design and data mining technology were used to investigate the dynamic influence on indexes due to process factors.The test results indicated that the reaction time,reaction temperature and the lithium feed are technological factors,and a regression equation of the mass fraction of Li-contained phosphates will be built,and expression can be built between each technological factors.Some factors exist interactions for testing index.Technological factors can be in greater scope for the synthesis of precursor at low temperature,but technological factors have a small craft scope in synthesis of LiMPO4 at high temperature.Especially reaction temperature and time will affect the quality of products directly via solid state reaction at high temperature.