Tailored Temperature‐Responsive Solvation Structures Enabling Ultra‐Wide‐Temperature Quasi‐Solid‐State Lithium Metal Batteries From −70°C to 60°C

ABSTRACT

Gel polymer electrolytes are essential for high‐energy‐density lithium metal batteries (LMBs), but their practical applications are limited by poor low‐temperature kinetics and insufficient high‐temperature stability. Notably, the wide‐temperature design of solvation structures is critical for the stable operation of wide‐temperature gel polymer electrolytes (WTGPEs). Herein, we contrive a novel temperature‐responsive gel polymer electrolyte (TRGPE) by finely tuning the ion–dipole interactions between Li ⁺ and solvent molecules. Leveraging the multi‐mode coordination ability of the multifunctional solvent molecule ethylene glycol diacetate (EGD) with Li ⁺ , the TRGPE endows the gel polymer electrolyte with a temperature‐responsive solvation structure, enabling high ionic conductivities and stable cycling in Li//LiCoO ₂ cells from −70°C to 60°C. At low temperatures, EGD binds Li ⁺ primarily via monocarbonyl coordination. As the temperature rises, EGD‐Li ⁺ coordination intensifies, whereas other components show an entirely distinct coordination tendency. Therefore, this anomalous coordination stabilizes high‐temperature solvation structures, promoting stable charge‐transfer processes. Additionally, EGD‐modulated solvation structures favor the formation of Li ₂ O‐rich inorganic solid electrolyte interphases (SEIs), significantly enhancing interfacial stability. Consequently, Li//LiCoO ₂ cells demonstrate high discharge capacities of 149 and 180 mAh g ⁻¹ at −70°C and 60°C, respectively. Preciously, this work establishes a new WTGPE system design paradigm through temperature‐responsive solvation engineering and inorganic‐rich SEI regulation.