School of Advanced Materials, Peking University Shenzhen Graduate School, Shenzhen 518055, China.
College of Energy, Xiamen University, Xiamen 361005, China.
Sci Bull (Beijing). 2023 Feb 26;68(4):408-416. doi: 10.1016/j.scib.2023.01.032. Epub 2023 Jan 20.
Despite the high theoretical capacity, silicon (Si) anode suffers from dramatical capacity loss, due to its massive volume swings (up to 300%) during cycling. Hence, thorough understanding of the structural evolution mechanism is necessary and essential for performance optimization of Si anode. Herein, a multi-scale three-dimensional (3D) image reconstruction technique is firstly applied to visualize the structural evolution process of Si anodes. Three key components (Si particles, inactive components, and voids) in the electrode are quantitatively analyzed by the focused ion beam and scanning electron microscope (FIB-SEM) technology. Furthermore, the average sizes of Si particles were run statistics during the cycling. By combining the componential observation within the electrode (macroscopic information) and the 3D models of the particle with solid electrolyte interphase (SEI) layer (microscopic information), the failure mechanism of Si anode is vividly demonstrated. This work establishes a new methodology to quantitatively analyze the structural and compositional evolution of Si anode, which could be further applied for the studies of many other electrode materials with similar issues.
尽管硅（Si）阳极具有很高的理论容量，但由于其在循环过程中体积剧烈膨胀（高达 300%），因此会导致容量急剧衰减。因此，深入了解结构演变机制对于优化 Si 阳极的性能是必要的。在此，首次应用多尺度三维（3D）图像重建技术来可视化 Si 阳极的结构演变过程。通过聚焦离子束和扫描电子显微镜（FIB-SEM）技术对电极中的三个关键组件（Si 颗粒、非活性组件和空隙）进行定量分析。此外，在循环过程中对 Si 颗粒的平均尺寸进行了统计。通过将电极内的成分观察（宏观信息）与具有固体电解质中间相（SEI）层的颗粒的 3D 模型（微观信息）相结合，生动地展示了 Si 阳极的失效机制。这项工作建立了一种定量分析 Si 阳极结构和组成演变的新方法，该方法可进一步应用于具有类似问题的许多其他电极材料的研究。
