The sluggish lithium diffusion at the electrode/electrolyte interface is one of the main obstacles to achieve superior rate capability of Li metal anodes for rechargeable batteries. Herein, a dense and uniform inorganic solid electrolyte interface (SEI) layer composed of ZrO 2 , Li 2 O, Li 3 N, and LiN x O y is constructed on the surface of Li metal via the spontaneous reaction between Li metal and zirconyl nitrate (ZrO(NO 3 ) 2 ) solution in dimethyl sulfoxide. The abundant grain boundaries in the artificial SEI created by the multicomponent enable the rapid diffusion of Li ions at the interface. As a result, the Li metal anode treated with zirconyl nitrate (LiZrO(NO 3 ) 2 @Li) delivers a stable cycle performance of over 550 h at a high current density of 10 mA cm −2 and a high areal capacity of 10 mAh cm −2 . When paired with a high-loading LiCoO 2 cathode (19 mg cm −2 ), the LiZrO(NO 3 ) 2 @Li anode shows much enhanced rate performance and long-term cycle stability without Li dendrite formation. The construction of an inorganic SEI layer with a high density of grain boundary provides new insights for the design of high-rate and dendrite-free Li metal anodes for high-energy-density batteries.

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, aphenoxy radical Spiro-O8 is proposed as an artificial protection film for Li metal anode owingt oi ts excellent filmforming capability and remarkable ionic conductivity.A spontaneous redoxr eaction between the Spiro-O8 and Li metal results in the formation of au niform 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 ah igh current density (4000 cycles at 10 mA cm À2 )a nd ah igh areal capacity of 5mAh cm À2 for 550 hwith an ultrahigh Li utilization rate of 54.6 %. As aproof of concept, this work shows afacile strategy to rationally fabricate dual-layered interfaces for Li metal anodes.

The dissolution of LiNO3 in carbonate electrolytes is achieved by introducing pyridine as a new carrier solvent owing to its higher Gutmann donor number than NO3-. The Li metal anode...