Micron silicon anodes for superior lithium storage: A view from chemical-mechanical degradation mechanisms to interface electrolyte systematic design

Silicon is considered as one of the most promising anodes for next-generation lithium-ion batteries (LIBs) due to its high theoretical specific capacity (3579 mAh/g) and abundant natural reserves. Compared to nano silicon, micron silicon offers distinct advantages, including lower specific surface area, reduced interfacial side reactions, higher initial coulombic efficiency, greater tap density, and lower cost, making it highly attractive for practical applications. However, its commercial viability is hindered by severe volume expansion, localized stress accumulation, repeated formation of unstable solid electrolyte interphase (SEI) layers, and electrical disconnection during cycling, which together result in rapid capacity fading and high irreversible capacity loss. Recent advances in electrolyte engineering, particularly interfacial modification strategies, have significantly improved the performance of micron silicon anodes by mitigating these challenges. This review provides an integrated perspective on the application of micron-sized silicon anodes by correlating lithium storage mechanisms, failure behaviors, and electrolyte-electrode interfacial evolution. Based on a systematic discussion of silicon lithiation/delithiation processes and associated structural instability, we clarify how interfacial degradation and irreversible lithium consumption govern the electrochemical performance of micron silicon. Then, electrolyte optimization strategies are critically analyzed, with an explicit comparison between liquid electrolyte regulation and solid-state electrolyte (SSE) design, highlighting their distinct roles in interfacial stabilization, stress accommodation, and cycling durability. From an electrolyte system design standpoint, this review summarizes integrated design principles for improving micron silicon performance and discusses the remaining challenges and opportunities toward their commercial application in high-energy-density battery systems.