三元正极材料LiNi1/3Co1/3Mn1/3O2的结构及第一性原理计算

以共沉淀法、喷雾干燥法制备了三元正极材料LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2,应用基于密度泛函理论的第一性原理计算方法,与实验制备的LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2进行对比,对3种不同的预想结构模型(堆叠结构、随机排列结构、超晶格结构)进行研究。实验结果表明,两种方法制备的三元材料都具有良好的层状结构,其中共沉淀法制备的层状结构更加明显,而喷雾干燥法制备的材料中过渡金属元素比更接近LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2的化学计量比。计算结果表明,随机排列的结构模型能量最低、最稳定,与实验制备的三元正极材料结构最为相似。

First-principles Study on Structure of Ternary Cathode Material LiNi1/3Co1/3Mn1/3O2

LiNi1/3Co1/3Mn1/3O2 as a promising cathode material was synthesized via co-precipitation and spray drying methods.The comparison between the prepared LiNi1/3Co1/3Mn1/3O2 and the three anticipated structure models (stacking,random and superlattice) were studied by the first-principle calculation.The experimental results show that both synthesized materials have good layer structure.The material synthesized via co-precipitation has a more obvious layer structure.As for the material prepared by spray drying method,the stoichiometric ratio among the transition metal element is closer to LiNi1/3Co1/3Mn1/3O2.Calculated results indicate that the random structure model has the lowest energy,which is most consistent with the experimental results.