Self-Healing Armor Enables Electrode Integrity and Interfacial Stability for Durable Silicon Anodes

Abstract Polymer coatings are widely used to stabilize silicon anodes, yet repeated volume changes can fracture the coating and accelerate continuous SEI reconstruction. Here, we construct a self-healing fluorinated acrylate/methacrylate copolymer coating in situ on silicon-based anodes through the UV-induced copolymerization of HFBA and MPS. The resulting copolymer combines strong adhesion with dynamic self-recovery through reversible dipole-dipole interactions, enabling microcrack repair within 1 min. Meanwhile, the HFBA-derived segments act as a fluorine reservoir, promoting the formation of a thin SEI with a polymer-rich outer layer and a LiF-rich inner layer. Consequently, SiOx-P(HFBA+MPS)||Li cells deliver 73.5% capacity retention after 500 cycles at 800 mA g–1. A practical 1.5 Ah NCM811||Si/C/Gr-P(HFBA+MPS) pouch cell achieves 71.9% capacity retention after 300 cycles and shows improved thermal safety. This work provides a scalable strategy for durable and safe silicon-based batteries by integrating autonomous self-healing of the polymer coating with sustained fluorine-assisted interphase stabilization.