Silicon-based anodes for solid-state batteries: challenges, opportunities, and multiscale strategies

Solid-state batteries (SSBs) have become a hot topic in next-generation energy storage research due to their high safety and potential high energy density. Si has a high theoretical specific capacity (4200 mAh g^-1), moderate lithium insertion potential (0.4 V vs. Li⁺/Li), and abundant resources, making it a subject of significant interest. However, its application is limited by factors such as significant volume expansion (>300%), interface dynamic instability, and slow reaction kinetics. In this work, the key challenges and opportunities of silicon-based anodes in SSBs are systematically reviewed. A multi-level synergistic design strategy is proposed, encompassing material alloying, nano-structuring, composite structure design, and optimization of electrode and electrolyte compatibility. Furthermore, prospects for future scientific research and commercialization of high-performance silicon-based SSBs are presented.