Henkel Pascal, Janek Jürgen, Mollenhauer Doreen
Institute of Physical Chemistry, Justus-Liebig University Giessen, 35392 Giessen, Germany.
Center for Materials Research (LaMa), Justus-Liebig University Giessen, 35392 Giessen, Germany.
Phys Chem Chem Phys. 2021 Oct 13;23(39):22567-22588. doi: 10.1039/d1cp01294k.
The potential of mobile applications for digital networking is constantly increasing. A key challenge is to ensure a reliable and long-term power supply. One possible solution is the use of all-solid-state thin-film lithium batteries which use amorphous lithium phosphorus oxynitride (LIPON) as solid electrolyte. It is well known that the electrochemical properties of this material are related to the amorphous state, which correlates with the nitrogen content. Due to the difficulty of calculating amorphous structures using first principles methods, three different LIPON structure models are considered in this study and the influence of the anion PON sublattice on the Li vacancy and Li interstitial formation as well as on the lithium ion transport is highlighted. While for all three model systems the migration energies of the energetically preferred Li vacancies increase with increasing complexity of the anion PON sublattice only slightly from 0.38 eV to 0.55 eV, the migration energies for the energetically preferred Li interstitials decrease with increasing complexity of the anion PON sublattice from 0.68 eV to 0.38 eV. Thus, it was found that the energetically preferred lithium ion (Li vacancy and Li interstitial ion) transport mechanism in LIPON can be explained on the basis of the present PON structural units. In the presence of isolated PON tetrahedra or periodic PON chains, the lithium vacancy diffusion dominates, whereas in the presence of periodic PON planes, the lithium interstitial diffusion becomes dominant.
移动应用程序在数字网络方面的潜力正在不断增加。一个关键挑战是确保可靠且长期的电源供应。一种可能的解决方案是使用全固态薄膜锂电池，该电池使用非晶态锂磷氮氧化物（LIPON）作为固体电解质。众所周知，这种材料的电化学性质与非晶态有关，而非晶态与氮含量相关。由于使用第一性原理方法计算非晶态结构存在困难，本研究考虑了三种不同的LIPON结构模型，并突出了阴离子PON亚晶格对锂空位和锂间隙形成以及锂离子传输的影响。虽然对于所有三个模型系统，能量上优先的锂空位的迁移能随着阴离子PON亚晶格复杂性的增加仅略有增加，从0.38 eV增加到0.55 eV，但能量上优先的锂间隙的迁移能随着阴离子PON亚晶格复杂性的增加从0.68 eV降低到0.38 eV。因此，发现LIPON中能量上优先的锂离子（锂空位和锂间隙离子）传输机制可以基于当前的PON结构单元来解释。在存在孤立的PON四面体或周期性PON链的情况下，锂空位扩散占主导，而在存在周期性PON平面的情况下，锂间隙扩散成为主导。
