Grain‐Boundary‐Rich Artificial SEI Layer for High‐Rate Lithium Metal Anodes.

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 ZrO2, Li2O, Li3N, and LiNxOy is constructed on the surface of Li metal via the spontaneous reaction between Li metal and zirconyl nitrate (ZrO(NO3)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(NO3)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 LiCoO2 cathode (19 mg cm−2), the LiZrO(NO3)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. [ABSTRACT FROM AUTHOR]