The paper investigates the stable electrodeposition of lithium in liquid and nanoporous solid electrolytes, addressing the significant challenges of dendrite formation and non-uniform metal deposition in rechargeable lithium, sodium, and aluminum metal-based batteries. The authors find that simple liquid electrolytes reinforced with halogenated salt blends, particularly lithium fluoride (LiF), exhibit stable long-term cycling at room temperature, with no signs of deposition instabilities over hundreds of cycles and thousands of operating hours. This stability is rationalized by surface energy data and impedance analysis, which show that the presence of halide anions, especially fluorides, significantly enhances the surface mobility of lithium. The study demonstrates that the addition of LiF to electrolytes can eliminate dendrite growth and improve cell lifetime by up to 25 times compared to control electrolytes. The findings support recent theoretical predictions that halide anions reduce the activation energy barrier for Li diffusion at the electrolyte-lithium metal interface, leading to enhanced stability of lithium electrodeposition. The results have important implications for the development of high-energy, safe electrochemical storage devices.The paper investigates the stable electrodeposition of lithium in liquid and nanoporous solid electrolytes, addressing the significant challenges of dendrite formation and non-uniform metal deposition in rechargeable lithium, sodium, and aluminum metal-based batteries. The authors find that simple liquid electrolytes reinforced with halogenated salt blends, particularly lithium fluoride (LiF), exhibit stable long-term cycling at room temperature, with no signs of deposition instabilities over hundreds of cycles and thousands of operating hours. This stability is rationalized by surface energy data and impedance analysis, which show that the presence of halide anions, especially fluorides, significantly enhances the surface mobility of lithium. The study demonstrates that the addition of LiF to electrolytes can eliminate dendrite growth and improve cell lifetime by up to 25 times compared to control electrolytes. The findings support recent theoretical predictions that halide anions reduce the activation energy barrier for Li diffusion at the electrolyte-lithium metal interface, leading to enhanced stability of lithium electrodeposition. The results have important implications for the development of high-energy, safe electrochemical storage devices.