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Constructing a stable artificial solid-electrolyte interphase has become one of the most effective strategies to overcome the poor reversibility of lithium metal anode, yet the protection role is still insufficient at elevated current densities over 10 mA cm−2 and large areal capacities over 10 mAh cm−2. Herein, we propose a dynamic gel with reversible imine groups, which is prepared via a cross linking reaction between flexible dibenzaldehyde-terminated telechelic poly(ethylene glycol) and rigid chitosan, to fabricate a protective layer for Li metal anode. The as-prepared artificial film shows combined merits of high Young's modulus, strong ductility and high ionic conductivity. When the artificial film is fabricated on a lithium metal anode, the thin protective layer shows a dense and uniform surface owing to the interactions between the abundant polar groups and lithium metal. Besides, the polar groups in the artificial film can homogenize the distribution of Li+ at the electrode/electrolyte interface. As a result, cycle stability over 3200 h under an areal capacity of 10 mAh cm−2 and a current density of 10 mA cm−2 has been obtained for the protected lithium metal anodes. Moreover, cycling stability and rate capability has been also improved in the full cells. Achieving stable lithium metal anodes under large current densities over 10 mA cm−2 and area capacities over 10 mAh cm−2 remains a critical challenge. Here, authors propose a dynamic gel as protect layer for lithium metal anode to facilitate with the Young's modulus, flexibility and ionic conductivity, thus to stabilize the lithium metal anode. [ABSTRACT FROM AUTHOR]

The uncontrollable dendrite growth of Li metal anode leads to poor cycle stability and safety concerns, hindering its utilization in high energy density batteries. Herein, a phenoxy radical Spiro‐O8 is proposed as an artificial protection film for Li metal anode owing to its excellent film‐forming capability and remarkable ionic conductivity. A spontaneous redox reaction between the Spiro‐O8 and Li metal results in the formation of a uniform and highly ionic conductive organic film in the bottom. Meanwhile, the phenoxy radicals on surface of Spiro‐O8 facilitate the decomposition of Li salt upon exposed to the ether electrolyte and lead the formation of LiF film on the top. Arising from the synergistic effects of inner high ionic conductive film and outer rigid film, stable Li plating/stripping can be realized at a high current density (4000 cycles at 10 mA cm−2) and a high areal capacity of 5 mAh cm−2 for 550 h with an ultrahigh Li utilization rate of 54.6 %. As a proof of concept, this work shows a facile strategy to rationally fabricate dual‐layered interfaces for Li metal anodes. [ABSTRACT FROM AUTHOR]