Single-Solvent-Based Electrolyte Enabling a High-Voltage Lithium-Metal Battery with Long Cycle Life

The application of Li-metal-anodes (LMA) can significantly improve the energy density of state-of-the-art lithium ion batteries. Lots of new electrolyte systems have been developed to form a stable solid electrolyte interphase (SEI) films, thereby achieving long-term cycle stability of LMA. Unfortunately, the common problem faced by these electrolytes is poor oxidation stability, which rarely supports the cycling of high-voltage Li-metal batteries (LMBs). In this work, a new single-component solvent dimethoxy(methyl)(3,3,3-trifluoropropyl) silane is proposed. The electrolyte composed of this solvent and 3 m LiFSI salt successfully supports the long-term cycle stability of limited-Li (50 & mu;m)||high loading LiCoO2 (& AP;20 mg cm(-2)) cell at 4.6 V. Experiments and theoretical research results show that the outstanding performance of the electrolyte in high-voltage LMBs is mainly attributed to its unique solvation structures and its great ability to build a highly stable and robust interphase on the surface of LMA and high-voltage cathodes. Interestingly, this proposed electrolyte system builds a stable SEI film rich in LiF and Li3N on the surface of LMA by improving the two-electron reduction activity of FSI- without adding LiNO3, the well-known additive used for LMBs. The design idea of the proposed electrolyte can guide the development of high-voltage LMBs.