Resolving electrochemically triggered topological defect dynamics and structural degradation in layered oxides

• 成果类型: Article
• 署名作者: Wang, Chunyang; Zhang, Rui; Li, Ju; Xin, Huolin L.
• 署名单位: University of California System; University of California Irvine; Chinese Academy of Sciences; Institute of Metal Research, CAS; Massachusetts Institute of Technology (MIT); Massachusetts Institute of Technology (MIT)
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-11296
• DOI: 10.1073/pnas.2409494122
• 发表日期: 2025-01-21
• 关键词: transmission electron-microscopy; ni-rich; cathodes; oxygen; dislocations; plasticity; lattice; linio2; bulk

摘要

Understanding topological defects- controlled structural degradation of layered oxides-a key cathode material for high- performance lithium- ion batteries-plays a critical role in developing next- generation cathode materials. Here, by constructing a nanobattery in an electron microscope enabling atomic- scale monitoring of electrochemcial reactions, we captured the electrochemically driven atomistic dynamics and evolution of dislocations-a most important topological defect in material. We deciphered how dislocations nucleate, move, and annihilate within layered cathodes at the atomic scale. Specifically, we found two types of dislocation configurations, i.e., single dislocations and dislocation dipoles. Both pure dislocation glide/climb and mixed motions were captured, and the dislocation glide and climb velocities were first experimentally measured. Moreover, dislocation activity- mediated structural degradation such as crack nucleation, phase transformation, and lattice reorientation was unraveled. Our work provides deep insights into the atomistic dynamics of electrochemically driven dislocation activities in layered oxides.