中文摘要：

基于密度泛函理论第一性原理计算的方法研究了锂离子电池正极材料LiVPO4F的晶体结构、电子结构、磁性、插入电压与扩散特性。结果表明,P-O共价键的稳定性较强,在脱锂过程中LiVPO4F的晶体结构始终保持稳定,体积变化率只有3%。费米能级附近的电子状态主要受V-3d轨道电子的影响,脱锂后体系带隙减小。体系脱锂前后都存在着自旋极化现象,脱锂后体系磁性减弱。LiVPO4F的平均插入电压为4.53 V,这与实验结果 4.30 V比较吻合。Li比其他的原子有十分明显的向外扩散的趋势。

英文摘要：

The lattice structure,electronic structure,magnetic property,insert voltage and the Li-ion diffusion properties of LiVPO4F cathode material have been investigated by first-principle calculation method based on the density-functional theory. The calculational results show that the lattice structure of LiVPO4F remains stable during the process of desorption of the Lithium. The percentage of volume change is only 3%; this can be attributed to the stability of P-O covalent bond. The bands near Fermi energy level are mostly formed by V-3d orbital electrons and the band gap energy of LiVPO4F is decreased. The spin polarization phenomenon is found for both systems and the magnetic moment decreases after desorption of Lithium. The averaged insert voltage of LiVPO4F is 4. 53V,which is in agreement with the experimental value of 4. 30V. The Li has obviously stronger diffusion capability comparing with others atoms.