title: Ammonium Additives to Dissolve Lithium Sulfide through Hydrogen Binding for High-Energy Lithium-Sulfur Batteries.
abstract: In rechargeable Li-S batteries, the uncontrollable passivation of electrodes by highly insulating Li2S limits sulfur utilization, increases polarization, and decreases cycling stability. Dissolving Li2S 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 Li2S 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 Li2S by forming complex ligands with S2-anions coupled with the solvent's solvating surrounding. Ammonium additives in electrolyte can also significantly improve the oxidation kinetics of Li2S, and therefore enable the direct use of Li2S 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.
authors.affiliation: Joint Center for Energy Storage Research, Pacific Northwest National Laboratory , Richland, Washington 99354, United States.
authors.forename: Huilin
authors.initials: H
authors.lastname: Pan
authors.affiliation: Joint Center for Energy Storage Research, Pacific Northwest National Laboratory , Richland, Washington 99354, United States.
authors.forename: Kee Sung
authors.initials: KS
authors.lastname: Han
authors.affiliation: Joint Center for Energy Storage Research, Pacific Northwest National Laboratory , Richland, Washington 99354, United States.
authors.forename: M
authors.initials: M
authors.lastname: Vijayakumar
authors.affiliation: Joint Center for Energy Storage Research, Pacific Northwest National Laboratory , Richland, Washington 99354, United States.
authors.forename: Jie
authors.initials: J
authors.lastname: Xiao
authors.affiliation: Joint Center for Energy Storage Research, Pacific Northwest National Laboratory , Richland, Washington 99354, United States.
authors.forename: Ruiguo
authors.initials: R
authors.lastname: Cao
authors.affiliation: Joint Center for Energy Storage Research, Pacific Northwest National Laboratory , Richland, Washington 99354, United States.
authors.forename: Junzheng
authors.initials: J
authors.lastname: Chen
authors.affiliation: Joint Center for Energy Storage Research, Pacific Northwest National Laboratory , Richland, Washington 99354, United States.
authors.forename: Jiguang
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Joint Center for Energy Storage Research, Pacific Northwest National Laboratory , Richland, Washington 99354, United States.
authors.forename: Karl T
authors.initials: KT
authors.lastname: Mueller
authors.affiliation: Joint Center for Energy Storage Research, Pacific Northwest National Laboratory , Richland, Washington 99354, United States.
authors.forename: Yuyan
authors.initials: Y
authors.lastname: Shao
authors.affiliation: Joint Center for Energy Storage Research, Pacific Northwest National Laboratory , Richland, Washington 99354, United States.
authors.forename: Jun
authors.initials: J
authors.lastname: Liu
keywords: NMR; ammonium additive; lithium sulfide; lithium sulfur batteries; solubility