Fluorinated Solid Electrolyte Interphase Derived From Fluorinated Polymer Electrolyte To Stabilize Li Metal
Jialong Fu, Zhuo Li, Xiaoyan Zhou, Zhiyong Li, Xin Guo
Abstract
Abstract Unstable interface between highly reductive Li metal and a conventional liquid electrolyte leads to uncontrollable Li dendrites and Li pulverization, thus limiting the practical applications of Li metal batteries with high energy density. Herein, a fluorinated quasi‐solid polymer electrolyte is synthesized to stabilize Li metal via the C−F/LiF enriched solid electrolyte interphase (SEI) derived from the fluorinated polymer skeleton. Benefiting from the homogenized ion plating/stripping process guided by lithophilic C−F and rapid Li + transportation assisted by LiF, Li dendrites and Li pulverization are suppressed. As a result, the Li||Li symmetrical cell with the fluorinated quasi‐solid polymer electrolyte remains stable over 1400 h at a current density of 0.3 mA cm −2 . LiNi 0.8 Co 0.1 Mn 0.1 O 2 ||Li battery delivers a long‐term cycling performance, where the capacity retains 87.77 % of its initial state after 300 cycles at 0.5 C in the voltage range from 2.8 to 4.4 V.