期刊
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
卷 163, 期 9, 页码 A2109-A2116出版社
ELECTROCHEMICAL SOC INC
DOI: 10.1149/2.0051610jes
关键词
-
资金
- United States Department of Energy, Office of Basic Energy Sciences, Division of Materials Science and Engineering [DE-SC0005397]
- National Science Foundation Graduate Research Fellowship Program (GRFP) [DGE-1110007]
- Belgian American Educational Foundation (BAEF)
- Ministry of Education [IBS-R019-D1]
- National Research Foundation of Korea [IBS-R019-D1]
- Ministry of Science, ICT & Future Planning, Republic of Korea [IBS-R019-D1-2016-A00] Funding Source: Korea Institute of Science & Technology Information (KISTI), National Science & Technology Information Service (NTIS)
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 degrees 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 similar to 9 mol% insoluble polysulfide species (mainly Li2S2) and similar to 91 mol% Li2S. 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 similar to 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. (C) The Author(s) 2016. Published by ECS. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据