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 (SF6 + 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 Li3N 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 Li3N) 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 LiNi0.9Co0.05Mn0.05O2 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.