Work

Achieving Ultra‐Thin Solid Electrolyte Interphase for High‐Performance Lithium Metal Anodes via Chloride‐Assisted Electrochemical Corrosion

Year: 2025

Type: article

Abstract: The thickness and composition of the solid electrolyte interphase (SEI) on lithium (Li) metal are critical factors influencing dendrite growth. This study introduces a novel electrolyte selection strategy based on electrochemical corrosion principles. By employing LiCl and LiNO 3 simultaneously, the electrolyte itself has a high donor number, low desolvation energy, high Li⁺ transference number and conductivity, and a moderate electrochemical stability window. In addition, it dynamically reduces the SEI thickness and reactivates dead Li, forming a ≈100 nm SEI enriched with LiF and Li 2 O on Li metal anode, which ensures the stable cycling of Li symmetric cells for 2000 h at a current density of 5 mA cm⁻ 2 . Consequently, Li metal cells using LiFePO 4 (LFP) as the cathode with the LiNO 3 ‐LiCl‐added electrolyte exhibit excellent cycling performance for 1600 cycles at 680 mA g⁻ 1 . Even with a thin Li metal anode, the Li (5 µm)|LFP cell retains 95% capacity after 70 cycles at 170 mA g⁻ 1 . The universality and feasibility of this electrolyte design are also validated in diverse battery chemistries such as anode‐free Cu|LFP, Li|LiNi 0.8 Mn 0.1 Co 0.1 O 2 (NMC811), and Li|S cells, as well as in pouch cells with high‐loading LFP and NMC811 cathodes, showcasing the promising electrolyte design strategy for Li metal batteries.

Source: Small

DOI: 10.1002/smll.202502682