Healable and conductive sulfur iodide for solid-state Li-S batteries

• 成果类型: Article
• 署名作者: Zhou, Jianbin; Chandrappa, Manas Likhit Holekevi; Tan, Sha; Wang, Shen; Wu, Chaoshan; Nguyen, Howie; Wang, Canhui; Liu, Haodong; Yu, Sicen; Miller, Quin R. S.; Hyun, Gayea; Holoubek, John; Hong, Junghwa; Xiao, Yuxuan; Soulen, Charles; Fan, Zheng; Fullerton, Eric E.; Brooks, Christopher J.; Wang, Chao; Clement, Raphaele J.; Yao, Yan; Hu, Enyuan; Ong, Shyue Ping; Liu, Ping
• 署名单位: University of California System; University of California San Diego; United States Department of Energy (DOE); Brookhaven National Laboratory; University of Houston System; University of Houston; University of Houston System; University of Houston; University of California System; University of California Santa Barbara; University of California System; University of California Santa Barbara; Johns Hopkins University; United States Department of Energy (DOE); Pacific Northwest National Laboratory; University of California System; University of California San Diego; University of Houston System; University of Houston; Honda Motor Company; Honda USA; University of California System; University of California San Diego
• 刊物名称: Nature
• ISSN/ISSBN: 0028-3742
• DOI: 10.1038/s41586-024-07101-z
• 发表日期: 2024-03-14
• 页码: 301-305
• 关键词: lithium; STABILITY; software; cathode

摘要

Solid-state Li-S batteries (SSLSBs) are made of low-cost and abundant materials free of supply chain concerns. Owing to their high theoretical energy densities, they are highly desirable for electric vehicles1-3. However, the development of SSLSBs has been historically plagued by the insulating nature of sulfur4,5 and the poor interfacial contacts induced by its large volume change during cycling6,7, impeding charge transfer among different solid components. Here we report an S9.3I molecular crystal with I2 inserted in the crystalline sulfur structure, which shows a semiconductor-level electrical conductivity (approximately 5.9 x 10-7 S cm-1) at 25 degrees C; an 11-order-of-magnitude increase over sulfur itself. Iodine introduces new states into the band gap of sulfur and promotes the formation of reactive polysulfides during electrochemical cycling. Further, the material features a low melting point of around 65 degrees C, which enables repairing of damaged interfaces due to cycling by periodical remelting of the cathode material. As a result, an Li-S9.3I battery demonstrates 400 stable cycles with a specific capacity retention of 87%. The design of this conductive, low-melting-point sulfur iodide material represents a substantial advancement in the chemistry of sulfur materials, and opens the door to the practical realization of SSLSBs. A conductive, low-melting-point and healable sulfur iodide material aids the practical realization of solid-state Li-S batteries, which have high theoretical energy densities and show potential in next-generation battery chemistry.