A high-rate and stable cycling of lithium metal anodes has been achieved using highly concentrated electrolytes composed of ether solvents and lithium bis(fluorosulfonyl)imide (LiFSI). This electrolyte enables high Coulombic efficiency (up to 99.1%) and prevents dendrite growth. A lithium|lithium cell can be cycled at 10 mA cm⁻² for over 6,000 cycles, while a copper|lithium cell can be cycled at 4 mA cm⁻² for over 1,000 cycles with an average Coulombic efficiency of 98.4%. These results are attributed to increased solvent coordination and lithium ion availability in the electrolyte. The study highlights the importance of electrolyte formulation in achieving stable and efficient lithium metal anodes for rechargeable batteries. The use of highly concentrated LiFSI-based electrolytes with ether solvents results in a compact and stable solid-electrolyte interphase (SEI) layer, which prevents further corrosion and ensures high cycling stability. The research demonstrates that the 4M LiFSI-DME electrolyte is optimal for achieving high-rate and stable cycling of lithium metal anodes. The findings provide a pathway for the development of safer and more efficient lithium metal batteries for advanced energy storage applications.A high-rate and stable cycling of lithium metal anodes has been achieved using highly concentrated electrolytes composed of ether solvents and lithium bis(fluorosulfonyl)imide (LiFSI). This electrolyte enables high Coulombic efficiency (up to 99.1%) and prevents dendrite growth. A lithium|lithium cell can be cycled at 10 mA cm⁻² for over 6,000 cycles, while a copper|lithium cell can be cycled at 4 mA cm⁻² for over 1,000 cycles with an average Coulombic efficiency of 98.4%. These results are attributed to increased solvent coordination and lithium ion availability in the electrolyte. The study highlights the importance of electrolyte formulation in achieving stable and efficient lithium metal anodes for rechargeable batteries. The use of highly concentrated LiFSI-based electrolytes with ether solvents results in a compact and stable solid-electrolyte interphase (SEI) layer, which prevents further corrosion and ensures high cycling stability. The research demonstrates that the 4M LiFSI-DME electrolyte is optimal for achieving high-rate and stable cycling of lithium metal anodes. The findings provide a pathway for the development of safer and more efficient lithium metal batteries for advanced energy storage applications.