CoPO_4离子筛卤水提锂热力学分析  

Thermodynamic Analysis of Li Extraction from Brine Using CoPO_4 Ion Sieve

作　　者：文燕儒 何利华[1] 刘旭恒[1] 

机构地区：[1]中南大学冶金与环境学院,湖南长沙410083

出　　处：《稀有金属与硬质合金》2016年第2期6-12,共7页Rare Metals and Cemented Carbides

基　　金：国家自然科学基金联合项目(U1407137)

摘　　要：通过同系线性规律对CoPO_4、Co_3(PO_4)_2及MeCoPO_4(Me=Li、Na、K、Mg_(0.5))等物质的Δ_fG~进行了估算,在热力学计算的基础上绘制了298.15K时Me-Co-P-H_2O体系的φ-pH曲线,对锂离子电池材料LiCoPO_4的提锂过程进行了热力学分析,讨论了CoPO_4对盐湖中Na^+、K^+、Mg^(2+)与Li+的吸附行为差异。结果表明:CoPO_4/LiCoPO_4电极在水溶液(pH=4~11)中能稳定存在;在实际卤水的离子浓度下,控制电位为0.066~0.201V(vs SHE),CoPO_4材料能在含有大量Na^+、K^+、Mg^(2+)的盐湖卤水中选择性吸附Li^+;调节氧化还原电位大于0.201V(vs SHE),嵌锂态CoPO_4离子筛材料中的Li^+可逆脱出。The Δ_fGθ of CoPO_4,Co_3（PO_4）_2 and MeCoPO_4（Me=Li,Na,K,Mg_（0.5））was estimated by congeneric linearity rule.Theφ-pH diagram of the Me-Co-P-H_2O system at 298.15 K was drawn according to the thermodynamic calculation.Thermodynamic analysis was made of lithium extraction using lithium ion battery electrode material LiCoPO_4,and the differences were discussed of adsorption behaviors between Na＋,K＋ or Mg2＋ and Li＋ in salt lake by CoPO_4.The results show that CoPO_4/LiCoPO_4 electrode is stable in aqueous solution（pH=4~11）.Controlling the redox potential of the system at 0.066~0.201V（vs SHE）,CoPO_4 material can absorb Li＋ selectively from the natural brine containing a large number of Na＋,K＋ and Mg2＋,and then Li＋can be desorbed reversibly from lithium-inserted CoPO_4 ion sieve material by controlling the redox potential over 0.201V（vs SHE）.

关 键 词：CoPO4离子筛 LiCoPO4 提锂 同系线性规律 热力学 吸附 卤水 

分 类 号：TQ021.2[化学工程]