In rechargeable Li-S batteries, the uncontrollable passivation of electrodes by highly insulating LiS limits sulfur utilization, increases polarization, and decreases cycling stability. Dissolving LiS in organic electrolyte is a facile solution to maintain the active reaction interface between electrolyte and sulfur cathode, and thus address the above issues. Herein, ammonium salts are demonstrated as effective additives to promote the dissolution of LiS to 1.25 M in DMSO solvent at room temperature. NMR measurements show that the strong hydrogen binding effect of N-H groups plays a critical role in dissolving LiS by forming complex ligands with S anions coupled with the solvent's solvating surrounding. Ammonium additives in electrolyte can also significantly improve the oxidation kinetics of LiS, and therefore enable the direct use of LiS as cathode material in Li-S battery system in the future. This provides a new approach to manage the solubility of lithium sulfides through cation coordination with sulfide anion.