Gupta Sunny, Yang Xiaochen, Ceder Gerbrand
Department of Materials Science & Engineering, University of California Berkeley, Berkeley, CA, 94720, USA.
Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
Nat Commun. 2023 Oct 28;14(1):6884. doi: 10.1038/s41467-023-42538-2.
Soft clay-like Li-superionic conductors, integral to realizing all-solid-state batteries, have been recently synthesized by mixing rigid-salts. Here, through computational and experimental analysis, we clarify how a soft clay-like material can be created from a mixture of rigid-salts. Using molecular dynamics simulations with a deep learning-based interatomic potential energy model, we uncover the microscopic features responsible for soft clay-formation from ionic solid mixtures. We find that salt mixtures capable of forming molecular solid units on anion exchange, along with the slow kinetics of such reactions, are key to soft-clay formation. Molecular solid units serve as sites for shear transformation zones, and their inherent softness enables plasticity at low stress. Extended X-ray absorption fine structure spectroscopy confirms the formation of molecular solid units. A general strategy for creating soft clay-like materials from ionic solid mixtures is formulated.
软黏土状锂超离子导体是实现全固态电池不可或缺的部分，最近通过混合刚性盐合成得到。在此，通过计算和实验分析，我们阐明了如何从刚性盐混合物中制备出软黏土状材料。利用基于深度学习的原子间势能模型进行分子动力学模拟，我们揭示了离子固体混合物形成软黏土的微观特征。我们发现，能够在阴离子交换时形成分子固体单元的盐混合物，以及此类反应的缓慢动力学，是形成软黏土的关键。分子固体单元充当剪切转变区的位点，其固有的柔软性使得材料在低应力下具有可塑性。扩展X射线吸收精细结构光谱证实了分子固体单元的形成。由此制定了一种从离子固体混合物中制备软黏土状材料的通用策略。
