论文标题
在分层锂和钠电池阴极材料中量化库仑相互作用
Quantification of Coulomb Interactions in layered Lithium and Sodium Battery Cathode Materials
论文作者
论文摘要
尽管电子相关性在锂离子阴极材料的第一原理描述中的重要性，但库仑相互作用参数通常被视为临时值。在实践中，通常依赖于U的参数处理方法来最佳地匹配实验观察到的物理特性，例如带隙或反应能量。在这里，使用受约束的随机相近似（CRPA）方法，我们对代表性的分层阴极材料（包括Li化合物，而且还）NA化合物的代表性分层阴极材料评估了库仑U和Hund J值。 LICOO2，LINIO2，LIMNO2，NACOO2，NANIO2和NAMNO2。我们发现，Li和Na化合物的库仑相互作用参数及其具有不同层堆叠的多晶型物的偏差不大，这表明了局部环境的主要作用，而不是全球结构特征的作用。我们已经分析了可变库仑参数的起源，这主要是由于本地化和筛选之间的竞争。我们为电池阴极材料提供了CRPA库仑参数，并通过观察系统的改进来描述实验观察到的平均平均插度电压和晶格参数来验证值。这些结果可用于第一原理计算以及基于模型的模拟模拟，以进行阴极系统的理论研究。
Despite the importance of the electron correlation in the first-principles description of the Li-ion cathode materials, the Coulomb interaction parameter, U is often treated as an ad hoc value. In practice, one usually relies on empirical ways of parametric treatment of U to optimally match the experimentally observed physical properties such as band gap or reaction energy. Here, using constrained random phase approximation (cRPA) method, we self-consistently evaluate the Coulomb U and Hund J values for representative layered cathode materials including not only Li compounds but also Na compounds; LiCoO2, LiNiO2, LiMnO2, NaCoO2, NaNiO2, and NaMnO2. We found that the Coulomb interaction parameters for Li and Na compounds and their polymorphs with different layer stackings do not deviate much, which shows the dominant role of local environment rather than of global structural features. We have analyzed the origin of variable Coulomb parameters, which is mainly due to the competition between the localization and screening. We provided cRPA Coulomb parameters for battery cathode materials and validate the values by observing systematic improvement in describing the experimentally observed average intercalation voltage and lattice parameters. These results can be applied for the first-principles calculations as well as model-based simulations for the theoretical investigation of cathode systems.
