Silicon is a promising anode material due to its high theoretical specific capacity, low lithiation potential and low lithium dendrite risk. Yet, the electrochemical performance of silicon anodes in solid-state batteries is still poor (for example, low actual specific capacity and fast capacity decay), hindering practical applications. Here the chemo-mechanical failure mechanisms of composite Si/Li₆PS₅Cl and solid-electrolyte-free silicon anodes are revealed by combining structural and chemical characterizations with theoretical simulations. The growth of the solid electrolyte interphase at the Si|Li₆PS₅Cl interface causes severe resistance increase in composite anodes, explaining their fast capacity decay. Solid-electrolyte-free silicon anodes show sufficient ionic and electronic conductivities, enabling a high specific capacity. However, microscale void formation during delithiation causes larger mechanical stress at the two-dimensional interfaces of these anodes than in composite anodes. Understanding these chemo-mechanical failure mechanisms of different anode architectures and the role of interphase formation helps to provide guidelines for the design of improved electrode materials.

硅因其高理论比容量、低锂电势和低锂枝晶风险而成为一种很有前景的负极材料。然而，固态电池中硅负极的电化学性能仍然较差（例如实际比容量低和容量衰减快），阻碍了实际应用。_{这里通过将结构和化学表征与理论模拟相结合，揭示了复合材料 Si/Li 6} PS ₅ Cl 和无固体电解质硅阳极的化学机械失效机制。_{Si|Li 6} PS ₅ Cl界面处固体电解质界面的生长导致复合阳极的电阻严重增加，这解释了它们的快速容量衰减。无固体电解质的硅阳极具有足够的离子和电子电导率，可实现高比容量。然而，脱锂过程中微尺度空隙的形成导致这些阳极的二维界面处比复合阳极产生更大的机械应力。了解不同阳极结构的这些化学机械失效机制以及界面形成的作用有助于为改进电极材料的设计提供指导。