Li-Ni-H_2O系的热力学分析

Thermodynamic analysis on Li-Ni-H_2O system

对现有的热力学数据进行评估,并进行热力学计算,绘制了在不同离子活度下的Li-Ni-H2O系E-pH图,利用该图对在水溶液中合成LiNiO2和回收废旧锂离子蓄电池的可能方案进行详细分析。结果表明,LiNiO2在水热力学稳定区内占据较大范围,通过软化学方法在水溶液中合成LiNiO2在热力学上是可行的。结合现有的资料及理论分析,认为在水溶液中合成LiNiO2的直接前驱体为:HNiO2-、Ni(OH)2和Ni3O4;间接前驱体为:Ni和Ni2+;湿法回收废旧锂离子蓄电池可能方案为:置于有还原剂存在的中性或弱碱性溶液中和有还原剂存在的弱酸性或中性溶液中。

Thermodynamic data were evaluated and calculated, the E-pH diagrams of Li-Ni-H2O system were drawn. According to the E-pH diagrams on different ion concentration,analyzed a possible method for synthesizing LiNiO2 and recovering valuable metal from waste Li-ion batteries in aqueous solution. Result expresses that LiNiO2 occupies the big scope in the water thermodynamics stability area, which is viable to synthesize the LiNiO2 in the aqueous solution by soft chemistry method in the thermodynamics. After analysing and approving with the present materials, direct precursor in synthesizing LiNiO2 in aqueous solution by soft chemistry method are HNiO2-、Ni(OH)2and Ni3O4;indirect precursor are Ni and Ni2+. Possible methods in recovering valuable metal from waste Li-ion batteries by hydrometallurgy are neuter or moderate acidic solution with reducing agent and neuter or moderate alkaline solution with reducing agent.