<p>Recently, in the field of lithium-ion batteries (LIBs), electrolytes with low salt concentrations (LCE, ≤ 0.5&#xa0;M) have attracted a lot of attention for its absolute price advantage. However, the Li⁺ solvation sheath containing a large number of solvent molecules not only results in a large Li⁺ desolvation energy but also derives an organic-dominated solid electrolyte interface (SEI) film with poor Li⁺ conductivity and ineffective passivation for graphite (Gr) electrode. To solve this problem, a non-solvated fluorobenzene (FB) diluent is introduced into the LCE system, with a volume ratio of 10%. Due to the strong dipole–dipole interaction between FB and carbonate solvents, the ion–dipole interaction between Li⁺ and carbonate solvents is weakened, effectively facilitating Li⁺ desolvation and resulting in a F/P-containing inorganics rich SEI film with fast Li⁺ transport dynamics. As a result, the electrochemical performance of the LFP/Gr cell assembled with FB-containing LCE is on par with that of the cell with 1.0&#xa0;M LiPF₆ EC/DEC. That is, the concentration of lithium salt is halved by the solvent engineering, while the performance is maintained. This study provides a theoretical basis for the design of LCE formula and is helpful in saving resources and reducing costs of LIBs.</p> Graphical Abstract <p>Through the dipole–dipole interaction between FB and carbonate solvent, the ion–dipole interaction between Li⁺ and carbonate solvent is weakened, thus forming a loose Li⁺-solvated structure.</p>