Sotoudeh Mohsen, Groß Axel
Institute of Theoretical Chemistry, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany.
Helmholtz Institute Ulm (HIU) for Electrochemical Energy Storage, Helmholtzstraße 11, 89069 Ulm, Germany.
JACS Au. 2022 Feb 11;2(2):463-471. doi: 10.1021/jacsau.1c00505. eCollection 2022 Feb 28.
Ion mobility is a critical performance parameter not only in electrochemical energy storage and conversion but also in other electrochemical devices. On the basis of first-principles electronic structure calculations, we have derived a descriptor for the ion mobility in battery electrodes and solid electrolytes. This descriptor is entirely composed of observables that are easily accessible: ionic radii, oxidation states, and the Pauling electronegativities of the involved species. Within a particular class of materials, the migration barriers are connected to this descriptor through linear scaling relations upon the variation of either the cation chemistry of the charge carriers or the anion chemistry of the host lattice. The validity of these scaling relations indicates that a purely ionic view falls short of capturing all factors influencing ion mobility in solids. The identification of these scaling relations has the potential to significantly accelerate the discovery of materials with desired mobility properties.
离子迁移率不仅是电化学能量存储与转换中的关键性能参数，也是其他电化学装置中的关键性能参数。基于第一性原理电子结构计算，我们推导出了一种用于描述电池电极和固体电解质中离子迁移率的描述符。该描述符完全由易于获取的可观测量组成：离子半径、氧化态以及所涉及物种的鲍林电负性。在特定类别的材料中，当电荷载流子的阳离子化学性质或主体晶格的阴离子化学性质发生变化时，迁移势垒通过线性标度关系与该描述符相关联。这些标度关系的有效性表明，单纯的离子观点不足以涵盖影响固体中离子迁移率的所有因素。识别这些标度关系有可能显著加速具有所需迁移特性的材料的发现。
