论文标题
第一原理研究小极化和LI扩散在分层licoo2中
First-principles study on Small Polaron and Li diffusion in layered LiCoO2
论文作者
论文摘要
锂离子电导率是确定锂离子电池阴极材料性能的重要特性之一。在这里，使用密度函数理论，我们研究了极化子稳定性及其对具有不同磁性有序的分层licoo2中锂离子扩散的影响。局部CO4+极极子出现在磁性构型中，并将LI-扩形屏障设置为〜0.34 eV。极化子也朝着与Li-diffusion方向相反的方向迁移。另一方面，极化子不会在非磁性结构中形成，而没有极性的LI扩散屏障为0.21 eV。尽管极化子的存在增加了扩散屏障，但在迁移过程中，磁有序结构在迁移过程中比非磁性情况更稳定。因此，我们的工作提倡孔极化的迁移情景进行锂离子扩散。此外，我们证明了CO离子的强电子相关性在稳定CO4+偏振子方面起着至关重要的作用。
Li-ion conductivity is one of the essential properties that determine the performance of cathode materials for Li-ion batteries. Here, using the density functional theory, we investigate the polaron stability and its effect on the Li-ion diffusion in layered LiCoO2 with different magnetic orderings. The localized Co4+ polaron appears in the magnetic configurations and sets the Li-diffusion barrier of ~0.34 eV. The polaron also migrates in the opposite direction to the Li-diffusion direction. On the other hand, the polaron does not form in the non-magnetic structure, and the Li diffusion barrier without the polaron is 0.21 eV. Although the existence of the polaron increases the diffusion barrier, the magnetically ordered structures are more energetically stable during the migration than the non-magnetic case. Thus, our work advocates the hole polaron migration scenario for Li-ion diffusion. Moreover, we demonstrate that the strong electron correlation of Co ions plays an essential role in stabilizing the Co4+ polaron.
