Na,As共掺杂锂离子正极材料LiFePO4的第一性原理计算

First-principle investigations of Na-As doping in Cathode Materials for Li-ion Batteries of LiFePO4

摘要: 采用基于密度泛函理论的第一性计算方法，研究了LiFePO4中Li、P位替位掺杂Na、As时的电子结构. 计算表明：少量掺杂并未整体改变LiFePO4电子结构，但可以调整体系中占主导地位的PO键、FeO键之间的相互作用，从而改善材料的特性；共掺杂体系的带隙宽度减小、嵌锂电位略微下降，掺入的Na、As未阻塞锂离子的一维通道.

Abstract: Na-As doped LiFePO4 has been investigated by using first-principle calculations based on density functional theory. The electronic structures of Na-As doped material are calculated, the results show that Na-As doping in small quantity could not change the inherent attribute of LiFePO4, but it was an effective way to modify material performance. The doped material has the narrow band gap and low Li-intercalation potential and the doping Na- As ions could not block the diffusion path of lithium ion.