Multiscale engineering of silicon anodes: linking structure, mechanics, interfaces, and commercialization

Abstract

Silicon has attracted significant attention as a next-generation anode material for lithium-ion batteries (LIBs) owing to its exceptionally high theoretical specific capacity (3579–4200 mAh g⁻¹), low lithiation potential, natural abundance, and compatibility with existing semiconductor manufacturing technologies. Despite these advantages, the commercialization of silicon anodes remains challenging because of severe volume expansion, unstable solid-electrolyte interphase (SEI) formation, mechanical degradation, and rapid capacity fading during repeated lithiation and delithiation. This review presents a comprehensive and design-oriented perspective on silicon anodes by integrating material properties, synthesis techniques, lithiation mechanisms, degradation pathways, and advanced engineering strategies within a unified framework. The fundamental design requirements for next-generation anodes, including high energy density, power density, cycle life, fast-charging capability, mechanical stability, initial Coulombic efficiency, cost-effectiveness, and sustainability, are first discussed. Subsequently, various silicon fabrication methods, nanostructured architectures, silicon-based composites, and multiscale modeling approaches are critically reviewed. The interconnected degradation mechanisms responsible for silicon-anode failure are analyzed, followed by a comprehensive evaluation of recent engineering strategies, including nanostructure optimization, interface engineering, silicon–carbon composites, advanced binders, electrolyte modification, and electrode architecture design. Finally, current research gaps, commercialization challenges, and future opportunities, including scalable manufacturing, sustainable silicon resources, artificial intelligence-assisted material design, and battery recycling, are discussed. This review provides practical design principles and future research directions for developing mechanically robust, electrochemically stable, and commercially viable silicon anodes for high-energy–density lithium-ion batteries.