Insight into the reaction mechanism of sulfur chains adjustable polymer cathode for high-loading lithium-organosulfur batteries

• 作者: Jinqiu Zhou Xi Zhou Yawen Sun Xiaowei Shen Tao Qian Chenglin Yan
• 来源期刊: 能源化学
• 年，卷（期）: 2021,（5）
• 页码范围: 238-244
• 页数: 7页
• 语种: 英文

摘要

Small molecules with adjustable sulfur atoms in the confined structure were acted as precursor for the synthesis of polymer cathodes for lithium-organosulfur batteries.Among them,poly(diallyl tetrasulfide) (PDATtS) delivered a high capacity of 700 mAh g-1,stable capacity retention of 85％ after 300 cycles,high areal capacity ～4 mAh cm-2 for electrode with up to 10.3 mg cm-2 loading.New insight into the reaction mechanism of PDATtS electrode that radicals arisen from the homolytic cleavage of S-S bond in PDATtS reacted with l.i+ to generate thiolates (RSLi) and insoluble lithium sulfides (Li2S) or lithium disulfide (Li2S2) was clearly verified by in-situ UV/Vis spectroscopy,nuclear magnetic resonance (NMR) studies and density-functional theory (DFT) calculations.Therefore,based on the unique reaction mechanism,problems of rapid capacity fading due to the formation of soluble polysulfide intermediates and their serious shuttle effect in conventional lithium-sulfur (Li-S) batteries was totally avoided,realizing the dendrite-free lithium sulfur batteries.This study sets new trends for avenues of further research to advance Li-S battery technologies.