Lithium metallic batteries (LMBs) supply distinctive theoretical vitality density and an ultra-low discount potential, making them a number one candidate for next-generation vitality storage. Nevertheless, challenges equivalent to dendritic lithium progress and electrolyte instability hinder their business viability by inflicting capability decline and security dangers. This examine presents an electrolyte formulation primarily based on a single-salt, single-solvent system of lithium bis(fluorosulfonyl)imide (LiFSI) in diethylene glycol diethyl ether (DEGDEE). The important thing benefit of this technique stems from a singular, anion-participating solvation construction, engineered by way of the molecular design of the DEGDEE solvent. This construction, notably at an optimized focus of 1.75 M LiFSI in DEGDEE, facilitates the formation of protecting layers on each the anode and cathode that successfully stabilize interfacial side-reactions, resulting in a major enhancement in cycle life. The ensuing Li||Cu cells exhibit a mean Coulombic effectivity of ~98% at each 25 °C and 60 °C, and Li||Li symmetric cells display ultra-stable biking for over 1500 h with a minimal polarization of ~0.02 V. When paired with sensible LiFePO4 cathodes, the total cell achieves a selected capability of 147 mAh g−1 attaining 85.4% capability retention over 1000 cycles at 25 °C and 163 mAh g−1 with 95.7% over 200 cycles at 60 °C, all whereas sustaining a excessive effectivity (99.8%) at 1.0 C. This work demonstrates that engineering the Li+ solvation construction by way of rational solvent design supplies a strong technique for creating extremely steady interfaces, advancing LMBs towards sensible, high-performance vitality storage.
