Molecular Engineering of Nitrile-Based Electrolytes by Oxygen Incorporation for Fast-Charging Lithium Metal Batteries

Nitrile-based solvents are highly promising candidates for advanced high-energy Li-metal batteries (LMBs); however, their practical application is hindered by poor interfacial compatibility with Li-metal anodes. Herein, a molecular design strategy involving the incorporation of oxygen into an organic nitrile solvent is proposed, which significantly enhances the compatibility of the modified solvent with Li-metal anodes and enables the formulation of a non-flammable electrolyte with improved performance for LMBs. The results demonstrate that this oxygen incorporation strategy not only enhances Li⁺ transport and interfacial reaction kinetics but also facilitates the formation of a thin and uniform solid electrolyte interphase (SEI). These improvements greatly boost the rate capability and cycling stability of LMBs, achieving a capacity retention of 81.6% after 1800 cycles at a high rate of 10 C. This work highlights the critical role of solvent molecular design in improving interfacial stability and ion transport in LMBs, offering a versatile and scalable strategy for the development of next-generation nitrile-based electrolytes for high-performance LMBs.