Na，As 共掺杂锂离子电池正极材料 LiFePO4的第一性原理研究

First-Principle Investigations of Na-As Doping in Cathode Materials for Li-Ion Batteries of LiFePO_4

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P—O键、Fe—O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.

Na-As doped LiFePO4 has been investigated by using first-principle calculation based on density func-tional 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 the mate-rial performance.The doped material has the narrow band gap and low Li-intercalation potential.The doping Na-As ions could not block the diffusion path of lithium ion.