(中南大学 冶金科学与工程学院， 长沙 410083)
摘 要: 运用同系线性规律对Li-Fe-P-H2O系中缺少的LiFePO4和Li3PO4的ΔG⊙进行估算。 结合已有的热力学数据， 运用φ—pH图的绘制原理， 得到25 ℃时Li-Fe-P-H2O系在不同浓度下的φ—pH图。 结果表明， 在水溶液中， LiFePO4具有较大的热力学稳定区域， 这对湿法制备LiFePO4很有利。 根据所绘制的热力学平衡图， 详细讨论了各种LiFePO4软化学制备方法的可行性途径， 并就液相法制备LiFePO4可能的技术途径和条件进行分析， 为在水溶液中用软化学法制备LiFePO4提供理论依据。
关键字: Li-Fe-P-H2O系； 磷酸铁锂； 热力学
Li-Fe-P-H2O system
（School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China）
Abstract:The ΔG⊙ of absent LiFePO4 and Li3PO4 in Li-Fe-P-H2O system were estimated by congeneric linearity rule. The potential—pH diagrams of Li-Fe-P-H2O system at the temperature of 25 ℃ and different ion concentration conditions were drawn through the basic potential—pH principle with a number of thermodynamic data. The potential—pH diagrams show that the predominant area of LiFePO4 in the Li-Fe-P-H2O systems is fairly large, which is beneficial to prepare the LiFePO4 by hydromethod. According to the potential—pH diagrams of Li-Fe-P-H2O system as well as published literatures, the potential processes and theoretical feasibility for synthesizing LiFePO4 using soft-chemical methods were discussed. The theoretical foundation for synthesizing LiFePO4 in the aqueous solution were provided by the potential—pH diagrams of Li-Fe-P-H2O system.
Key words: Li-Fe-P-H2O system; LiFePO4; thermodynamics
