In Situ Electrochemical Interfacial Manipulation Enabling Lithiophilic Li Metal Anode with Inorganic‐Rich Solid Electrolyte Interphases for Stable Li Metal Batteries
Subin Kim, Ki‐Yeop Cho, JunHwa Kwon, Kiyeon Sim, KwangSup Eom, Thomas F. Fuller
Abstract
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.