Anchored Weakly‐Solvated Polymer Electrolyte for Operating Lithium‐Metal Batteries Under Extreme Cold Conditions

Abstract

Lithium metal batteries (LMBs) face significant issues from insufficient ion transport dynamics within bulk electrolytes, as well as sluggish charge transfer at electrolyte|electrode interfaces, due to the limited de‐solvated behaviors. These factors are enlarged and constrain the reversibility and kinetics of polymer‐based LMBs at low temperature. Herein, a weakly‐solvated chemistry strategy to lose the Li+/solvent interaction has been demonstrated successfully, solving the charge‐transfer issues at ultra‐low temperature for polymerized 1,3‐Dioxolane (PDOL)‐based LMBs. The intense participation of anion donors in the solvation structure with decreased temperature significantly accelerates the desolvation process of Li+ and endows the rapid formation of the inorganic‐rich bilayer solid‐electrolyte interphase (SEI), leading to the enhanced‐dynamics interfacial chemistry at low temperature, which is crucial for achieving highly reversible plating/stripping behaviors (≈99.6% of Coulombic efficiency) and avoiding dendritic growth even at 5 mAh cm−2. These insights are applied in practical Li metal full‐cells, exhibiting evolutionary temperature reversibility, prolonged cycling lifespan, and excellent rate capability at low temperatures. These findings underscore the crucial role of weakly‐solvated structure in ion transport/interfacial reaction kinetics for low‐temperature polymer‐based LMBs.