(中南大學(xué) 冶金科學(xué)與工程學(xué)院， 長(zhǎng)沙 410083)
摘 要: 運(yùn)用同系線性規(guī)律對(duì)Li-Fe-P-H2O系中缺少的LiFePO4和Li3PO4的ΔG⊙進(jìn)行估算。 結(jié)合已有的熱力學(xué)數(shù)據(jù)， 運(yùn)用φ—pH圖的繪制原理， 得到25 ℃時(shí)Li-Fe-P-H2O系在不同濃度下的φ—pH圖。 結(jié)果表明， 在水溶液中， LiFePO4具有較大的熱力學(xué)穩(wěn)定區(qū)域， 這對(duì)濕法制備LiFePO4很有利。 根據(jù)所繪制的熱力學(xué)平衡圖， 詳細(xì)討論了各種LiFePO4軟化學(xué)制備方法的可行性途徑， 并就液相法制備LiFePO4可能的技術(shù)途徑和條件進(jìn)行分析， 為在水溶液中用軟化學(xué)法制備LiFePO4提供理論依據(jù)。
關(guān)鍵字: Li-Fe-P-H2O系； 磷酸鐵鋰； 熱力學(xué)
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
