Fluorine-Free Lithium Metal Batteries with a Stable\nLiF-Free Solid Electrolyte Interphase

Abstract

Lithium\nfluoride (LiF), generated by the decomposition of fluoride\nin lithium metal batteries (LMBs), is considered an essential component\nfor stabilizing metallic Li. However, the substantial introduction\nof fluorine in batteries raises potential environmental concerns.\nIn this study, we designed a fluorine-free LMB by integrating a fluorine-free\nelectrolyte and a fluorine-free binder to construct a B/O/N hybrid\nsolid electrolyte interphase (SEI) capable of providing good stability\nand fast Li⁺ transport ability. At a test temperature of\n60 °C, the LiF-free SEI can achieve a highly reversible Li plating/stripping\nefficiency, with a Coulombic efficiency of 98.8% under conditions\nof 3 mA cm^–2 and 3 mAh cm^–2. Furthermore,\nthe F-free LMB battery exhibits a rapid charging/discharging rate\nof 100 C with a capacity exceeding 80 mAh g^–1 and\ndemonstrates stable cycling performance over 500 cycles at 50 C. The\nfast-charging capability was further verified in practical Li–LiFePO₄ full cells.