Functional Interface Design Stabilizes Li‐Ion Storage in Si Anodes

Silicon (Si) has emerged as an ideal material for next-generation high-energy-density lithium (Li)-ion batteries owing to its ultrahigh theoretical capacity and low working voltage. However, severe volume changes during electrochemical reactions cause the pulverization of active Si and continuous degradation of interfacial structures amongst internal components, resulting in rapid capacity fading. To address these challenges, designing functional nanoscale interfaces in Si anodes is critical for enhancing the Li-ion storage stability. This review systematically elaborates the recent advances in the interface engineering of Si-based anodes from a multiscale interface perspective, mainly focusing on the interfaces generated by the functional coatings, liquid/solid electrolytes, polymer binders, and modified current collectors. The principles of interface design and dynamic structural evolution as well as the regulation of Li-ion-transfer or charge-transfer kinetics at various interfaces are comprehensively analyzed. Feasible strategies to enhance electrochemical performance through the interface design are also highlighted. This review concludes by summarizing the current challenges in interface engineering and outlining future research directions. It provides fundamental theoretical guidance and practical insights from the perspective of interface design for developing high performance Si anodes.