Glasses are promising electrolytes for use in solid-state batteries. Nevertheless, due to their amorphous structure, the mechanisms that underlie their ionic conductivity remain poorly understood. Here, ab initio molecular dynamics is used to characterize migration processes in the prototype glass, 75Li₂S–25P₂S₅. Lithium migration occurs via a mechanism that combines concerted motion of lithium ions with large, quasi-permanent reorientations of PS₄³⁻ anions. This latter effect, known as the ‘paddlewheel’ mechanism, is typically observed in high-temperature crystalline polymorphs. In contrast to the behavior of crystalline materials, in the glass paddlewheel dynamics contribute to Lithium-ion mobility at room temperature. Paddlewheel contributions are confirmed by characterizing spatial, temporal, vibrational, and energetic correlations with Lithium motion. Furthermore, the dynamics in the glass differ from those in the stable crystalline analogue, γ-Li₃PS₄, where anion reorientations are negligible and ion mobility is reduced. These data imply that glasses containing complex anions, and in which covalent network formation is minimized, may exhibit paddlewheel dynamics at low temperature. Consequently, these systems may be fertile ground in the search for new solid electrolytes.

玻璃是用于固态电池的有前途的电解质。然而，由于其无定形结构，对其离子导电性基础的机理仍然知之甚少。在这里，从头算分子动力学用于表征原型玻璃75Li ₂ S–25P ₂ S ₅中的迁移过程。锂迁移是通过将锂离子的协调运动与PS ₄ ^3-的大而准永久性重新定向相结合的机制发生的阴离子。通常在高温晶体多晶型物中观察到后一种效应，称为“叶轮”机制。与晶体材料的行为相反，玻璃桨轮动力学在室温下有助于锂离子迁移率。通过表征与锂运动的空间，时间，振动和能量相关性，可以确定桨轮的作用。此外，在玻璃中的动力学从那些在稳定的结晶类似物不同，γ-栗₃ PS ₄，其中阴离子的重新取向可忽略不​​计且离子迁移率降低。这些数据表明，含有复杂阴离子且共价网络形成最小的玻璃可能在低温下表现出桨轮动力学。因此，这些系统在寻找新的固体电解质方面可能是沃土。