Elucidating the Electrochemical Activity of Electrolyte-Insoluble Polysulfide Species in Lithium-Sulfur Batteries
- Univ. of Texas, Austin, TX (United States). Materials Science and Engineering Program and Texas Materials Inst.
- Univ. of Texas, Austin, TX (United States). Dept. of Chemistry; Center for Multidimensional Carbon Materials, Inst. for Basic Science, Ulsan (Korea)
- Center for Multidimensional Carbon Materials, Inst. for Basic Science, Ulsan (Korea); Ulsan National Inst.of Science and Technology, Ulsan (Korea)
The direct synthesis of Li2S2, a proposed solid intermediate in the discharge of lithium-sulfur (Li-S) batteries, was accomplished by treating elemental lithium with sulfur in liquid ammonia at -41°C. The as-synthesized product was analyzed by X-ray photoelectron spectroscopy (XPS) as well as X-ray diffraction (XRD) and determined to be a mixture of crystalline Li2S, amorphous Li2S2, and higher-order polysulfides (Li2Sx, x > 2). Monitored filtration followed by a tailored electrochemical approach was used to successfully remove the higher-order polysulfides and yielded a powder, which was determined by XPS to be comprised of ~9 mol% insoluble polysulfide species (mainly Li2S2) and ~91 mol% Li2S. Here, this material was discharged galvanostatically in an electrochemical cell and, despite the lack of soluble polysulfide species, was shown to exhibit a discharge plateau at ~2.1 V vs. Li/Li+. This result confirmed the electrochemical reducibility of electrolyte-insoluble polysulfides in Li-S batteries. Moreover, it was determined that the reduction of solid polysulfides was confined to areas where the sulfur-sulfur bonds were in intimate contact with the conductive current collector. Finally, it was observed that commercially available Li2S samples contain significant quantities of polysulfide-type impurities.
- Research Organization:
- Univ. of Texas, Austin, TX (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- Grant/Contract Number:
- SC0005397
- OSTI ID:
- 1436410
- Journal Information:
- Journal of the Electrochemical Society, Vol. 163, Issue 9; ISSN 0013-4651
- Publisher:
- The Electrochemical SocietyCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
One‐Pot Synthesis of a Copolymer Micelle Crosslinked Binder with Multiple Lithium‐Ion Diffusion Pathways for Lithium–Sulfur Batteries
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journal | January 2020 |
Current-density dependence of Li 2 S/Li 2 S 2 growth in lithium–sulfur batteries
|
journal | January 2019 |
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