The state-of-the-art lithium-ion batteries are made of layered intercalation cathode, graphite anode and electrolytes made of linear and cyclic carbonates. Ethylene carbonate (EC) remains significant in preventing solvent co-intercalation into graphite by forming unique solid electrolyte interface (SEI) layer. However, EC has low melting point (36 °C) and high Li⁺ desolvation barrier at the interface. At subzero temperature, these batteries encounter sluggish kinetics and high interfacial impedance. Here, we report 5 M lithium bis(fluorosulfonyl)imide salt in tetrahydrofuran (THF) solvent as novel low temperature electrolyte. The combination of low melting point of THF (-109 °C), and modified solvation structure resulting in inorganic rich SEI chemistry enabling superior room and ultralow temperature electrochemical performance. Various spectroscopic techniques and molecular dynamics (MD) simulations are carried out to understand the solvation structure. Graphite half-cells with this advanced electrolyte exhibit 90 % capacity retention after 300 charge-discharge cycles at room temperature. Also, 90 % of its room temperature capacity is retained at -20 °C with superior cyclability. LiNi_0.6Co_0.2Mn_0.2O₂||graphite full-cells could retain 80 % of its room temperature capacity at -20°C and repeated charge and discharge at -40 °C, providing a new way of designing low temperature electrolytes for LIBs.