Revealing Irradiation-Induced Dynamic Structural Failure in LiCoO2 Cathodes via Electron-Temperature-Dependent Deep Potential Molecular Dynamics

Abstract

In lithium-ion batteries (LIBs) used for deep-space exploration, LiCoO₂ cathode materials face significant challenges in high-radiation environments, including structural degradation and ion migration. This study investigates the dynamic structural evolution of LiCoO₂ under irradiation using the electron-temperature-dependent deep potential (ETD-DP) model. Compared with traditional ab initio molecular dynamics (AIMD) simulations, the ETD-DP method extends both the spatial and temporal scales by several orders of magnitude. The results reveal that LiCoO₂’s response to irradiation occurs on the nanosecond time scale, divided into three stages: ion traversal, intense local structural adjustment, and structure relaxation. During the intense adjustment stage, irradiation induces the migration of transition metal ions toward the lithium layers. In the structure relaxation stage, cobalt ions displaced from their equilibrium positions form a dumbbell structure with adjacent Co ions. The simulation results were validated through high-energy electron beam experiments using aberration-corrected electron microscopy. This study provides valuable insights for improving the irradiation tolerance of LIB cathode materials and offers new perspectives on the application of high-energy particle-beam-based fine structural characterization techniques in advanced battery applications.