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.
出处
《分子科学学报》
CAS
CSCD
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)
关键词
锂离子电池
FEPO4
密度泛函
lithium-ion battery
LiFePO4
density function theory
