From Passive Cocoon to Active Metamorphosis: High‐Current‐Driven Evolution of Silicon for Ultrastable Anodes

ABSTRACT The commercial viability of silicon anodes in lithium‐ion batteries remains heavily impeded by severe volume expansion, unstable solid‐electrolyte interphases (SEI), and the necessity for restrictive low‐current pre‐lithiation. While improving initial Coulombic efficiency (ICE), low‐current activation accelerates progressive capacity decay over extended cycling and prevents fast‐charging. Furthermore, conventional nanostructuring operates on a paradigm of mere passive containment, leaving root electrochemical instabilities fundamentally unresolved. Inspired by butterfly metamorphosis, we introduce a biomimetic electrochemical paradigm. Analogous to endogenous enzymes driving transformation within a protective cocoon, we employ an initial high current as an “electrochemical enzyme” to trigger the controlled size reduction of Si confined within a covalent organic framework (COF) “cocoon.” Regulated by this architecture, the high‐current pulse drives controlled Si pulverization, synchronously realizing in situ pre‐lithiation and generating a stable amorphous Li‐Si phase via a comprehensively elucidated synergistic mechanism. Benefiting from this structural evolution, the engineered anode exhibits superior robustness. It retains 74.5% and 71.9% capacity over 2000 cycles at 10 000 and 20 000 mA g −1 , respectively, and successfully accommodates extreme fast charging (118 s). By conceptualizing a transition from passive containment to active in situ regulation, this study unveils a transformative design paradigm for high‐energy, high‐power battery materials.