In Situ Electrochemical Interfacial Manipulation Enabling Lithiophilic Li Metal Anode with Inorganic‐Rich Solid Electrolyte Interphases for Stable Li Metal Batteries

Lithium‐metal anodes (LMAs) are the ultimate choice for realizing high‐energy‐density batteries; however, its use is hindered by problematic Li growth in the form of dendrites. To alleviate dendritic Li growth, the preparation of LMAs with a lithiophilic current collector (CC) is effective; however, applying a lithiophilic CC to LMAs is still challenging due to the manufacturing complexity involved in the separate lithiophilic treatment and lithiation processes. Herein, a facile one‐pot LMA fabrication method by utilizing thiourea (TU) as a precursor is proposed. A lithiophilic Cu 2 S layer is formed on Cu foam (CF) by the in situ electrochemical oxidation of TU (Cu x SCF), and the lithiation of CC is performed via subsequent Li electrodeposition (Li@Cu x SCF). The Cu 2 S on Cu x SCF can lead to uniform Li deposition by providing lithiophilic sites, and it is converted to form ionic‐conductive Li 2 S‐rich solid electrolyte interphase layer. Resultantly, Cu x SCF significantly enhances the cycling performance of LMAs compared to CF. Specifically, a LiFePO 4 /Li@Cu x SCF full‐cell lithium‐metal battery (LMB) with a low n / p ratio (1.6) exhibits capacity retention of 95.6% at 0.5 C (220 cycles) and can maintain 85.0% of initial capacity (425 cycles, n / p = 4) at 2.0 C. LMBs with LiNi 0.6 Co 0.2 Mn 0.2 and LiNi 0.8 Co 0.1 Mn 0.1 also exhibit improved electrochemical performance.