( 中南大學(xué) 冶金科學(xué)與工程學(xué)院， 長(zhǎng)沙 410083)
摘 要: 繪制了25℃時(shí)Mn-H2O與Li-Mn-H2O系的ε-pH圖， 并對(duì)鋰離子電池用正極材料錳酸鋰的濕化學(xué)制備以及溶液中鋰的回收問(wèn)題從熱力學(xué)上進(jìn)行了分析， 指出了可能的技術(shù)途徑和對(duì)策； 計(jì)算發(fā)現(xiàn)， LiMn2O4完全或部分地占據(jù)了各種價(jià)態(tài)錳離子化合物的穩(wěn)定區(qū)域， 在水溶液中的穩(wěn)定性很好。 這對(duì)濕法制備LiMn2O4十分有利； 而LiMnO2的穩(wěn)定性較差， 僅在溶液中維持較高鋰離子濃度時(shí)才可存在。 濕法制備LiMnO2的條件較為苛刻； 對(duì)于從溶液中回收鋰， 錳的固體氧化物如MnO2無(wú)疑是極佳的吸附劑， 理論上有很高的回收率。 吸附的鋰宜采用提高溶液電勢(shì)的方法進(jìn)行氧化性解吸。
關(guān)鍵字: Li-Mn-H2O系； 熱力學(xué)； 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
