In Situ Interphasial Engineering Enabling High‐Rate and Long‐Cycling Li Metal Batteries

Abstract The practical implementation of Li metal anode has long been hindered by the significant challenges of notorious dendritic Li growth and severe interphase instability during repeated cycling. Herein, a highly lithiophilic NiSe‐modified host has rationally been constructed to stabilize Li metal by the facile mechanical rolling strategy. The in situ configurated high‐flux Li 2 Se‐enriched interphase layer can facilitate the fast interfacial charge transfer, high Li plating/stripping reversibility and homogeneous Li nucleation/growth. Consequently, the achieved modified Li metal demonstrates ultrahigh rate capability (10 mA cm −2 ) and ultralong‐term cycling stability (6600 cycles) with dendrite‐free Li deposition. The Li|LiFePO 4 (LFP) cell exhibits an extraordinarily long lifespan cycling stability over 500 cycles with an ultra‐low decay rate of only ≈0.0092% per cycle at 1 C. Furthermore, the 4.5 V high‐voltage Li|LiCoO 2 pouch cell with a high areal capacity (≈1.9 mAh cm −2 ) still reveals an impressively prolonged cyclability over 200 cycles even under the harsh test condition of low negative‐to‐positive‐capacity (N/P) ratio of ≈3.4 and lean electrolyte of ≈5.5 µL mAh −1 . This work provides a facile and scalable strategy toward a highly stable Li metal anode for reliable practical usage.