A new electrolyte based on dimethyl 2,5-dioxahexanedioate (DMDOHD) solvent is reported for high-performance 5 V-class lithium-based batteries. This electrolyte, composed of 1 M lithium hexafluorophosphate (LiPF₆) in DMDOHD, exhibits enhanced stability towards both the highly reactive lithium metal anode and high anodic stability. Unlike conventional carbonate-based electrolytes, which suffer from low lithium plating/stripping efficiency and dendritic growth, the DMDOHD-based electrolyte achieves a high lithium plating/stripping efficiency of 92% while suppressing dendrite growth, even without additives or co-solvents. This is attributed to the ability of the electrolyte to form a robust, homogeneous SEI layer. Additionally, the DMDOHD-based electrolyte is highly compatible with the high-voltage LiNi₀.₅Mn₁.₅O₄ positive electrode material, demonstrating excellent room-temperature cycling stability with over 94% capacity retention after 250 cycles at a C/3 rate. The addition of fluoroethylene carbonate (FEC) additive further improves performance, achieving 98% lithium plating/stripping efficiency and 97% capacity retention. The DMDOHD-based electrolyte also exhibits high anodic stability up to 5.2 V vs. Li/Li⁺ and superior thermal stability compared to conventional carbonate-based electrolytes. It also shows improved safety due to its high flash point and thermal stability. The electrolyte's unique solvation structure and interaction with Li⁺ ions contribute to its enhanced performance, with a balanced composition of inorganic and organic species in the SEI, leading to good rigidity and flexibility. The DMDOHD-based electrolyte also forms a stable, conformal, and dense CEI, which suppresses electrolyte oxidation and maintains the stability of the positive electrode/electrolyte interface. The study confirms that the DMDOHD-based electrolyte is a promising candidate for future high-voltage lithium-based battery applications.A new electrolyte based on dimethyl 2,5-dioxahexanedioate (DMDOHD) solvent is reported for high-performance 5 V-class lithium-based batteries. This electrolyte, composed of 1 M lithium hexafluorophosphate (LiPF₆) in DMDOHD, exhibits enhanced stability towards both the highly reactive lithium metal anode and high anodic stability. Unlike conventional carbonate-based electrolytes, which suffer from low lithium plating/stripping efficiency and dendritic growth, the DMDOHD-based electrolyte achieves a high lithium plating/stripping efficiency of 92% while suppressing dendrite growth, even without additives or co-solvents. This is attributed to the ability of the electrolyte to form a robust, homogeneous SEI layer. Additionally, the DMDOHD-based electrolyte is highly compatible with the high-voltage LiNi₀.₅Mn₁.₅O₄ positive electrode material, demonstrating excellent room-temperature cycling stability with over 94% capacity retention after 250 cycles at a C/3 rate. The addition of fluoroethylene carbonate (FEC) additive further improves performance, achieving 98% lithium plating/stripping efficiency and 97% capacity retention. The DMDOHD-based electrolyte also exhibits high anodic stability up to 5.2 V vs. Li/Li⁺ and superior thermal stability compared to conventional carbonate-based electrolytes. It also shows improved safety due to its high flash point and thermal stability. The electrolyte's unique solvation structure and interaction with Li⁺ ions contribute to its enhanced performance, with a balanced composition of inorganic and organic species in the SEI, leading to good rigidity and flexibility. The DMDOHD-based electrolyte also forms a stable, conformal, and dense CEI, which suppresses electrolyte oxidation and maintains the stability of the positive electrode/electrolyte interface. The study confirms that the DMDOHD-based electrolyte is a promising candidate for future high-voltage lithium-based battery applications.