Wang Chunyang, Zhang Rui, Li Ju, Xin Huolin L
Department of Physics and Astronomy, University of California, Irvine, CA 92697.
Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China.
Proc Natl Acad Sci U S A. 2025 Jan 21;122(3):e2409494122. doi: 10.1073/pnas.2409494122. Epub 2025 Jan 13.
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.
理解拓扑缺陷控制的层状氧化物（高性能锂离子电池的关键正极材料）的结构退化，对开发下一代正极材料起着至关重要的作用。在此，通过在电子显微镜中构建一个能够对电化学反应进行原子尺度监测的纳米电池，我们捕捉到了电化学驱动的原子动力学以及位错（材料中最重要的拓扑缺陷）的演变。我们在原子尺度上破译了位错在层状阴极内如何形核、移动和湮灭。具体而言，我们发现了两种位错构型，即单个位错和位错偶极子。我们捕捉到了纯位错滑移/攀移以及混合运动，并首次通过实验测量了位错滑移和攀移速度。此外，还揭示了位错活动介导的结构退化，如裂纹形核、相变和晶格重新取向。我们的工作为层状氧化物中电化学驱动的位错活动的原子动力学提供了深刻见解。
