A Sustainable Fully Fluorine‐Free Interfacial Chemistry for Reversible Anode‐Free Lithium Metal Batteries

ABSTRACT Anode‐free lithium metal batteries promise high energy density. However, fluorinated electrolytes raise sustainability concerns. Herein, we develop a fully fluorine‐free interfacial strategy by coupling a cross‐linked vinylene carbonate‐N,N′‐methylenebisacrylamide artificial solid electrolyte interphase (ASEI) on Cu current collectors with a fluorine‐free electrolyte to regulate both lithium deposition and subsequent SEI formation. This combination offers an alternative to interfacial stabilization using fluorinated SEI‐forming components or alloy‐forming interlayers. The ASEI possesses strong Li‐ASEI interactions and enhanced lithiophilicity, thereby enabling homogeneous and compact Li deposition with reduced growth overpotential. Furthermore, the ASEI induces the formation of a conformal, mechanically robust, inorganic‐rich SEI containing Li 2 O and Li 3 N, leading to improved interfacial stability and the reversibility of Li plating/stripping. Consequently, the ASEI‐modified current collector delivers markedly improved full‐cell performance. The prelithiated LFP||ASEI‐Cu full cell achieves stable cycling over 350 cycles with a capacity retention of 84.5% at 25°C, while the prelithiated NCM811||ASEI‐Cu full cell delivers a reversible capacity of 146.8 mAh g −1 after 100 cycles with a capacity retention of 86.6% at 25°C. This work demonstrates the potential of fluorine‐free interfacial engineering for anode‐free lithium metal batteries, while further improvements in lithium‐inventory retention and high‐current‐density operation remain necessary for practical implementation.