Simulation trajectories from ab-initio molecular dynamics of 4x4x4 super cell of Li3OCl with 4 Li concentrations

Lithium-rich oxychloride antiperovskites are promising solid electrolytes for enabling next-generation batteries. Here, we report a comprehensive study varying Li+ concentrations in Li3OCl using ab-initio molecular dynamics simulations. The simulations accurately capture the complex interactions between Li+ vacancies (V'Li), the dominant mobile species in Li3OCl. The V'Li polarize and distort the host lattice, inducing additional non-vacancy mediated diffusion mechanisms and correlated diffusion events that reduce the activation energy barrier at concentrations as low as 1.5% V'Li. Our analyses of discretized diffusion events Li in both space and time illustrate the critical interplay between correlated dynamics, polarization, and local distortion in promoting ionic conductivity in Li3OCl.

富锂氯氧化物反钙钛矿（Lithium-rich oxychloride antiperovskites）是一类极具应用前景的下一代电池固体电解质。本文采用从头算分子动力学模拟（ab-initio molecular dynamics simulations），针对Li₃OCl体系中Li⁺浓度的调控开展了系统性研究。该模拟精准捕获了Li₃OCl中作为主导载流子的锂离子空位（Li+ vacancies, V'Li）之间的复杂相互作用。V'Li会对主体晶格产生极化与畸变，诱导出额外的非空位介导扩散机制与关联扩散事件，在V'Li浓度低至1.5%时即可降低扩散活化能垒。我们对时空维度下离散化的Li扩散事件开展分析，揭示了关联动力学、极化效应与局部畸变之间的关键协同机制，该机制可显著提升Li₃OCl的离子电导率。