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Abstract Lithium‐ion batteries (LIBs) suffer from energy loss and safety hazards under high‐rate conditions, because of the sluggish electrochemical kinetics and unstable interfacial passivation. Herein, a PC‐based electrolyte using weakly solvated solvent ethyl trifluoroacetate is developed to improve interfacial kinetics and stability in LIBs. A microsolvating competition is revealed in the bulk electrolyte, forming a loose Li + coordination configuration with benign Li + affinity and high ionic conductivity. Furthermore, an inorganic‐rich interphase is constructed on a graphite anode, affording smooth Li + desolvation and reliable passivation. Consequently, the NCM622/graphite cell in PC‐based electrolyte shows improved cycling stability (82.2% after 200 cycles) and rate capability (83% at 4C compared to 0.1C) at a high‐voltage of 4.5 V, much better than those of EC‐based electrolyte (76.2% after 200 cycles and 74% at 4C). Additionally, the PC‐based electrolyte affords reversible operation at –40 °C while the EC‐based electrolyte fails at –40 °C. This work highlights the potential of solvation structure engineering for low‐energy‐barrier electrolyte.
Qin et al. (Thu,) studied this question.