The realization of practical lithium metal batteries depends critically on achieving stable and reversible lithium plating and stripping at the anode interface. Conventional carbonate electrolytes suffer from poor compatibility with lithium metal due to the instability of LiPF₆ and the formation of a fragile, inhomogeneous solid electrolyte interphase (SEI). This study introduces a dual-salt electrolyte system based on competitive solvation between NO₃⁻ and PF₆⁻ ions, which fundamentally transforms the interfacial chemistry and enables dendrite-free, high-efficiency cycling.
In this design, LiNO₃ is dissolved in tetraethylene glycol dimethyl ether (TEGDME) and blended into a standard LiPF₆/EC-DMC electrolyte. The introduction of NO₃⁻ anions disrupts the dominant Li⁺–PF₆⁻ and Li⁺–solvent interactions through preferential coordination. Spectroscopic analysis confirms that NO₃⁻ becomes the primary ligand in the first solvation shell, significantly reducing the participation of PF₆⁻ and carbonate solvents. This shift suppresses the hydrolysis and thermal degradation of LiPF₆, thereby preventing the release of HF and PF₅—key agents responsible for SEI breakdown and continuous electrolyte consumption.
As a result, the reduction of NO₃⁻ at the lithium surface leads to the in situ formation of a robust, Li₃N-rich SEI film. X-ray photoelectron spectroscopy (XPS) reveals abundant Li₃N, LiNxOy, and LiNO₂ species, all of which exhibit high ionic conductivity and chemical stability. The SEI acts as a selective ion conductor, facilitating uniform Li⁺ flux across the interface. According to the diffusion-reaction competition mechanism, rapid ion transport promotes radial growth of lithium deposits, resulting in smooth, dense, and columnar morphologies rather than mossy or dendritic structures.Methyl 3-iodopropiolate Autophagy Scanning electron microscopy shows no cracks or dead lithium accumulation even after 30 cycles.Diphenyl sulfide medchemexpress
Electrochemical evaluation demonstrates exceptional performance.PMID:35069563 The optimized 50%-DSE achieves a Coulombic efficiency of 97.3% over 210 cycles at 0.5 mA cm⁻² and 1.0 mAh cm⁻², far surpassing the baseline LiPF₆ electrolyte, which exhibits rapid decay after ~30 cycles. Voltage profiles remain stable, with minimal polarization increase, indicating low and consistent interfacial resistance. Impedance spectra show no significant rise in charge transfer resistance, confirming the long-term integrity of the SEI.
This work highlights the power of molecular-level control through anion competition. By engineering the solvation environment, it becomes possible to steer the reduction pathway toward desired products, stabilize the SEI, and enable highly reversible lithium deposition. The proposed strategy offers a generalizable approach for designing next-generation electrolytes that combine high voltage stability, excellent cycling durability, and inherent safety—critical requirements for the commercialization of lithium metal batteries.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com