Plasma-Engineered Hybrid Interphase Induces Preferred Lithium Deposition for Enhanced Lithium Metal Anodes

The construction of a high-quality artificial solid electrolyte interphase (SEI) on lithium metal anodes is of great importance to regulate preferred crystal orientation, thereby realizing interfacial stability and dendrite suppression. Herein, we develop a novel low-temperature gas–liquid composite source (SF 6 + silane coupling agent) plasma method for synthesis of dense inorganic–organic hybrid SEI on lithium metal anodes. The designed hybrid SEI layer consists of inorganic LiF and Li 3 N and organic lithium compounds (e.g., Li–O–Si). In-situ and ex-situ XRD results demonstrate that the modified hybrid SEI can induce preferential growth of the Li(110) crystal plane, thereby promoting lateral and dendrite-free morphology, in contrast to the (200)-oriented vertical dendrites of bare lithium. The preferential growth of the Li(110) plane is due to the synergistic effect of inorganic components (LiF and Li 3 N) and lithium compounds in SEI, which can enhance interfacial structural stability and inhibit dendrite propagation. Consequently, symmetric cells with modified Li metal anodes (P-SEI@Li) exhibit exceptional stability over 900 h at 1 mA cm –2 /1 mAh cm –2 with a low overpotential of ∼11 mV. Full cells with LiNi 0.9 Co 0.0 5 Mn 0.05 O 2 cathodes show improved capacity retention. This work demonstrates the effectiveness of plasma-engineered SEI in regulating crystal plane deposition and provides new insights for developing high-performance lithium metal batteries.