Regenerative Artificial Solid Electrolyte Interphase via Dynamic Cross-Linking for Stable Lithium Metal Anodes

Artificial solid electrolyte interphases (ASEIs) are widely used to stabilize lithium metal anodes, yet their protection inevitably degrades because polymer coatings crack under repeated volume fluctuation and inorganic SEI components detach during cycling. Herein, we present a dynamic crosslinked fluoropolymer (DCF) artificial interphase that simultaneously enables autonomous polymer crack healing and continuous replenishment of inorganic SEI components. The dynamic interphase is constructed from a layer of poly (2,2,2-trifluoroethyl acrylate) cross-linked by ureido-pyrimidinone, whose reversible quadruple hydrogen bonds enable rapid self-healing of the polymer network and effective closure of interfacial cracks. Additionally, the fluorine-rich polymer matrix serves as a persistent source for LiF formation, continuously replenishing the inorganic inner layer to compensate for detachment during cycling. Benefiting from this dual regenerative mechanism of polymer self-healing and inorganic component self-replenishment, lithium metal anodes protected by the dynamic interphase exhibit highly stable plating and stripping for over 4000 h in symmetric cells. In full cells, a LiFePO₄||Li cell retained 90.67% of its capacity after 1000 cycles, while a high-loading LiNi_0.6Co_0.2Mn_0.2O₂ (NCM622) pouch cell maintained 70% capacity after 700 cycles at 1C.