Intermolecular Hydrogen Bonding Tailors Solvation Structures for Low-Temperature and Long-Cycling Lithium-Ion Batteries

Lithium iron phosphate/graphite (LFP/Gr) batteries are widely recognized for their excellent safety performance; however, their practical application under low-temperature and fast-charging conditions remains challenging due to sluggish lithium-ion interfacial dynamics. In this work, a nitrile-based electrolyte containing N,N-dimethyltrifluoroacetamide (FDMA) is reported, which modulates lithium-ion solvation through hydrogen bonding with the nitrile solvent (IBN), thereby optimizing interfacial transport and stabilizing the solid electrolyte interphase (SEI) at low temperatures. The Ah-level LFP/Gr batteries with this electrolyte demonstrate outstanding cycling stability, maintaining 99.9% capacity retention over 800 cycles at -20 °C. Furthermore, the electrolyte delivers a discharge capacity of 759 mAh at -40 °C, more than three times higher than that of the baseline EC/DEC electrolyte. At room temperature, the pouch cells sustain 80% capacity retention after 535 cycles at a 2C fast-charging rate with an average coulombic efficiency of 99.9%. This electrolyte design, driven by hydrogen-bond-regulated solvation structure, significantly enhances low-temperature performance and cycling stability while maintaining excellent stability at room and elevated temperatures. These findings provide valuable insights for developing next-generation electrolytes aimed at lithium-ion batteries operating under extreme conditions. © 2025 Wiley-VCH GmbH.