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Sulfur‐Deficient TiS 2‐x for Promoted Polysulfide Redox Conversion in Lithium‐Sulfur Batteries
Author(s) -
Zhao Yingyue,
Cai Wenlong,
Fang Yuting,
Ao Huaisheng,
Zhu Yongchun,
Qian Yitai
Publication year - 2019
Publication title -
chemelectrochem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.182
H-Index - 59
ISSN - 2196-0216
DOI - 10.1002/celc.201900269
Subject(s) - polysulfide , sulfur , x ray photoelectron spectroscopy , electrochemistry , redox , electrode , cathode , annealing (glass) , adsorption , chemistry , electron paramagnetic resonance , materials science , inorganic chemistry , chemical engineering , metallurgy , physics , nuclear magnetic resonance , engineering , electrolyte
Sulfur‐deficient TiS 2–x is prepared through high temperature vacuum annealing. Electron spin resonance (ESR) and X‐ray photoelectron spectroscopy (XPS) data confirm the presence of sulfur vacancies in TiS 2–x . Effective polysulfide adsorption and promotion to polysulfide redox conversion was proven by adsorption simulation experiments and electrochemical measurements. Thus, TiS 2–x is used as cathode promoter for Li−S half‐cells to improve the overall electrochemical performance. As expected, the TiS 2–x /S electrode shows a high and stable capacity of 751 mAh g −1 even after 500 cycles and a fade rate as low as 0.04 % per cycle at 1 C. Besides, the high sulfur loading of the electrode of 4 mg cm −2 also displays an admirable cycling performance of 963 mAh g −1 with a capacity retention up to 91.7 % over 50 cycles at 0.2 C.