Chemisorption of polysulfides through redox reactions with organic molecules for lithium-sulfur batteries

• Published in: Nature communications Vol. 9; no. 1; pp. 705 - 10
• Main Authors: Li, Ge, Wang, Xiaolei, Seo, Min Ho, Li, Matthew, Ma, Lu, Yuan, Yifei, Wu, Tianpin, Yu, Aiping, Wang, Shun, Lu, Jun, Chen, Zhongwei
• Format: Journal Article
• Language: English
• Published: England Nature Publishing Group 16.02.2018; Nature Publishing Group UK; Nature Portfolio
• Subjects: Anthraquinone; Bonding strength; Cathodes; Chemical bonds; Chemisorption; Cycles; Decay rate; Dissolution; ENERGY STORAGE; Flux density; Lewis acid; Lithium; Organic chemistry; Polysulfides; Redox properties; Redox reactions; Species diffusion; Sulfur; Sulfur content
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-018-03116-z

Lithium-sulfur battery possesses high energy density but suffers from severe capacity fading due to the dissolution of lithium polysulfides. Novel design and mechanisms to encapsulate lithium polysulfides are greatly desired by high-performance lithium-sulfur batteries towards practical applications. Herein, we report a strategy of utilizing anthraquinone, a natural abundant organic molecule, to suppress dissolution and diffusion of polysulfides species through redox reactions during cycling. The keto groups of anthraquinone play a critical role in forming strong Lewis acid-based chemical bonding. This mechanism leads to a long cycling stability of sulfur-based electrodes. With a high sulfur content of ~73%, a low capacity decay of 0.019% per cycle for 300 cycles and retention of 81.7% over 500 cycles at 0.5 C rate can be achieved. This finding and understanding paves an alternative avenue for the future design of sulfur-based cathodes toward the practical application of lithium-sulfur batteries.