Decoupling Chemo‐Mechanical Degradation for Scalable Silicon‐Based Solid‐State Batteries

Silicon-based solid-state batteries (Si-SSBs) have emerged as a pivotal next-generation energy storage technology to surpass the energy density ceiling of conventional lithium-ion batteries. However, their practical deployment is impeded by severe chemo-mechanical degradation at the silicon anode-solid electrolyte interface due to the substantial volumetric expansion and interfacial contact loss. This review systematically reviews the underlying chemo-mechanical failure mechanisms through advanced operando characterization, connecting atomic-scale dynamics to macroscopic performance decay. This review then evaluates interfacial stabilization strategies for solid electrolytes through utilizing the viscoelastic buffers via in situ polymerization, and surface wettability and passivation of inorganic solid electrolytes, and the design of the mechanically reinforced polymer composites, with the objective of harmonizing ionic conductivity with mechanical compliance. Furthermore, the coupling between mechanical stress and electrochemical stability is elucidated through integrated material design and multiscale modeling. Finally, critical engineering considerations for scalability and manufacturing are discussed to bridge the gap between laboratory and practical Si-SSBs.