锂离子电池正极材料LiFePO_4的密度泛函研究  

Density functional study of cathode material LiFePO_4 for lithium ion battery

作　　者：陈昌国[1] 刘艳[1] 司玉军[2] 鲁蕴甜[1] 王丽[1] 郑洪波[1] 

机构地区：[1]重庆大学化学化工学院,重庆400030 [2]四川理工学院化学系,四川自贡643000

出　　处：《分子科学学报》2007年第4期248-252,共5页Journal of Molecular Science

基　　金：国家自然科学基金资助项目(29734130)

摘　　要：采用密度泛函(B3LYP)方法计算锂离子电池正极材料LiFePO4/FePO4,净电荷和共价键级的计算结果都表明磷氧原子间作用力最强,锂氧原子间作用力最弱,有利于Li离子在晶格中的自由移动.以Li/LiFePO4锂离子电池的平均电压为3.2 V,和实验值3.4 V基本一致.态密度分析表明FePO4和LiFePO4都是典型的半导体,O原子轨道主要贡献总态密度靠费米能级价带一侧,Fe原子轨道主要贡献总态密度靠费米能级导带一侧.LiFePO4 and FePO4 as cathode materials for lithium-ion batteries are studied by the DFT/ B3LYP method. The results of net charges and covalent bond orders show that： interaction forces between P-O atoms is the strongest,interaction forces between Li-O atoms is the weakest. It helps to move freely in crystal lattice for lithium ion. The calculated average open-voltage of Li/LiFePO4 battery 3.2 V, is basically agreement with 3. 4 V that was experimentally observed. Density of state （DOS） reveals that both LiFePO4 and FePO4 are typical semiconductors, O atom orbit mainly contributes to the highest valence band near to the Fermi level, Fe atom orbit mainly contributes to the lowest conduction band.

关 键 词：锂离子电池 FEPO4 密度泛函 

分 类 号：O641[理学—物理化学]