Upgrading Ester‐Based Electrolyte with LiNO ₃ and GPE to Realize Dendrite‐Free Lithium Deposition

Abstract The development of high‐energy‐density lithium metal batteries (LMBs) is significantly hindered by the interfacial degradation occurring at lithium metal anodes (LMAs) in ester‐based electrolyte systems. Herein, multivalent acrylates, possessing two, three, and four carbonyl groups are investigated as functional co‐solvents to enhance LiNO ₃ solubility in ester‐based electrolytes. The results reveal a positive correlation between carbonyl group number and LiNO ₃ dissolution capability. Molecular dynamic simulations suggest that incorporating LiNO ₃ through multivalent co‐solvent reshapes the Li⁺ solvation sheath, favoring inorganic‐rich solid electrolyte interphase (SEI) formation. A precursor liquid electrolyte containing 7.5 vol% neopentyl glycol diacrylate and 1.0 wt.% LiNO ₃ is in situ polymerized to form gel polymer electrolyte (GPE‐7.5). X‐ray photoelectron spectroscopy and electrochemical impedance spectrum analyses show that GPE‐7.5 can mitigate the decomposition of LiPF ₆ and electrolyte solvents to construct an inorganic‐rich SEI dominated by LiF and Li ₃ N and promote dendrite‐free deposition on LMAs. The NCM622|GPE‐7.5|Li cell delivers exceptional cycle stability and high Coulombic efficiency with minimal polarization growth, attributed to the inorganic‐rich solid electrolyte interphase formed on both LMA and NCM622 surfaces. The strategy of incorporating LiNO ₃ in GPE provides new insights for the design of advanced high‐energy‐density LMBs.