( 中南大学 冶金科学与工程学院， 长沙 410083)
摘 要: 绘制了25℃时Mn-H2O与Li-Mn-H2O系的ε-pH图， 并对锂离子电池用正极材料锰酸锂的湿化学制备以及溶液中锂的回收问题从热力学上进行了分析， 指出了可能的技术途径和对策； 计算发现， LiMn2O4完全或部分地占据了各种价态锰离子化合物的稳定区域， 在水溶液中的稳定性很好。 这对湿法制备LiMn2O4十分有利； 而LiMnO2的稳定性较差， 仅在溶液中维持较高锂离子浓度时才可存在。 湿法制备LiMnO2的条件较为苛刻； 对于从溶液中回收锂， 锰的固体氧化物如MnO2无疑是极佳的吸附剂， 理论上有很高的回收率。 吸附的锂宜采用提高溶液电势的方法进行氧化性解吸。
关键字: Li-Mn-H2O系； 热力学； LiMn2O4； LiMnO2
Li-Mn-H2O system
（ College of Metallurgical Science and Engineering,
Central South University, Changsha 410083, China）
Abstract: The ε-pH diagrams of Mn-H2O and Li-Mn-H2O systems at 25℃ were drawn according to thermodynamic calculation. The technological routes associated with the synthesis of Li-Mn-O materials for rechargeable lithium ion battery, as well as the recovery of lithium from salt lake solution by sorption methods, were discussed in detail. It appears that LiMn2O4 is fairly stable in aqueous system since it occupies whole or part of the predominant area of manganese compounds. This is beneficial for preparing LiMn2O4 by hydromethods. On the contrary, it is relatively difficult to obtain LiMnO2 because LiMnO2 can exist only when the lithium concentration is high and the system potential is low. MnO2, with high theoretical recovery, is a very nice absorbent for extracting lithium from solution. By increasing solution potential, lithium can be desorbed from MnO2.
Key words: Li-Mn-H2O system ; thermodynamics ; LiMn2O4 ; LiMnO2
