The continuously increasing demand of high-energy-density lithium-ion batteries (LIBs) has stimulated the development of high-capacity electrode materials. Among the promising candidates, silicon (Si)-based anodes stand out because of their theoretical specific capacity (1000–4200 mAh g^-1), low redox potential (~0.4 V versus Li/Li⁺), environmental friendliness, and low costs. However, their large volume swing (100%–300%) upon lithiation/delithiation process leads to the pulverization of active particles and the continuous generation of an unstable and thick solid electrolyte interphase (SEI). In order to obtain new insights into the evolution of structural disintegration in Si anode during the cycling, Yang and co-workers successfully developed focused ion beam and scanning electron microscope (FIB-SEM) as a new experimental tool to analyze the structural change of bulk Si anodes during cycling. The three-dimensional (3D)-modeled structural evolution of both Si electrodes and single Si particles were reconstructed by sequential slicing, which enables to visually and quantitatively identify the dynamic change of active materials, inactive components (e.g., SEI), and voids. This cover image depicts the use of FIB-SEM technology to analyze the structural evolution in the Si anode. By providing a clearer picture of the structural evolution in Si anodes from different scales, the proposed strategy might be suitable for characterizing other electrode materials with significant morphology changes (see the article by Chen Zhu on page 408).

The continuously increasing demand of high-energy-density lithium-ion batteries (LIBs) has stimulated the development of high-capacity electrode materials. Among the promising candidates, silicon (Si)-based anodes stand out because of their theoretical specific capacity (1000–4200 mAh g^-1), low redox potential (~0.4 V versus Li/Li⁺), environmental friendliness, and low costs. However, their large volume swing (100%–300%) upon lithiation/delithiation process leads to the pulverization of active particles and the continuous generation of an unstable and thick solid electrolyte interphase (SEI). In order to obtain new insights into the evolution of structural disintegration in Si anode during the cycling, Yang and co-workers successfully developed focused ion beam and scanning electron microscope (FIB-SEM) as a new experimental tool to analyze the structural change of bulk Si anodes during cycling. The three-dimensional (3D)-modeled structural evolution of both Si electrodes and single Si particles were reconstructed by sequential slicing, which enables to visually and quantitatively identify the dynamic change of active materials, inactive components (e.g., SEI), and voids. This cover image depicts the use of FIB-SEM technology to analyze the structural evolution in the Si anode. By providing a clearer picture of the structural evolution in Si anodes from different scales, the proposed strategy might be suitable for characterizing other electrode materials with significant morphology changes (see the article by Chen Zhu on page 408).