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

Jianbin Zhou; Manas Likhit Holekevi Chandrappa; Sha Tan; Shen Wang; Chaoshan Wu; Howie Nguyen; Canhui Wang; Haodong Liu; Sicen Yu; Quin R S Miller; Gayea Hyun; John Holoubek; Junghwa Hong; Yuxuan Xiao; Charles Soulen; Zheng Fan; Eric E Fullerton; Christopher J Brooks; Chao Wang; Raphaële J Clément; Yan Yao; Enyuan Hu; Shyue Ping Ong; Ping Liu

doi:10.1038/s41586-024-07101-z

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

Nature. 2024 Mar;627(8003):301-305. doi: 10.1038/s41586-024-07101-z. Epub 2024 Mar 6.

Authors

Jianbin Zhou^#¹, Manas Likhit Holekevi Chandrappa^#¹, Sha Tan², Shen Wang¹, Chaoshan Wu³, Howie Nguyen⁴, Canhui Wang⁵, Haodong Liu¹, Sicen Yu¹, Quin R S Miller⁶, Gayea Hyun¹, John Holoubek¹, Junghwa Hong¹, Yuxuan Xiao⁷, Charles Soulen¹, Zheng Fan⁸, Eric E Fullerton⁷, Christopher J Brooks⁹, Chao Wang⁵, Raphaële J Clément⁴, Yan Yao³, Enyuan Hu², Shyue Ping Ong^{10

11}, Ping Liu^{12

13}

Affiliations

¹ Department of Nanoengineering, University of California, San Diego, La Jolla, CA, USA.
² Chemistry Division, Brookhaven National Laboratory, Upton, NY, USA.
³ Materials Science and Engineering Program and Texas Center for Superconductivity at the University of Houston, University of Houston, Houston, TX, USA.
⁴ Materials Department and Materials Research Laboratory, University of California, Santa Barbara, CA, USA.
⁵ Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, USA.
⁶ Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland, WA, USA.
⁷ Center for Memory and Recording Research, University of California, La Jolla, San Diego, CA, USA.
⁸ Department of Engineering Technology, University of Houston, Houston, TX, USA.
⁹ Honda Research Institute USA, 99P Labs, Columbus, OH, USA.
¹⁰ Department of Nanoengineering, University of California, San Diego, La Jolla, CA, USA. ongsp@ucsd.edu.
¹¹ Sustainable Power and Energy Center, University of California, San Diego, La Jolla, CA, USA. ongsp@ucsd.edu.
¹² Department of Nanoengineering, University of California, San Diego, La Jolla, CA, USA. piliu@ucsd.edu.
¹³ Sustainable Power and Energy Center, University of California, San Diego, La Jolla, CA, USA. piliu@ucsd.edu.

^# Contributed equally.

PMID: 38448596
DOI: 10.1038/s41586-024-07101-z

Abstract

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 vehicles^1-3. However, the development of SSLSBs has been historically plagued by the insulating nature of sulfur^4,5 and the poor interfacial contacts induced by its large volume change during cycling^6,7, impeding charge transfer among different solid components. Here we report an S_9.3I molecular crystal with I₂ inserted in the crystalline sulfur structure, which shows a semiconductor-level electrical conductivity (approximately 5.9 × 10^-7 S cm^-1) at 25 °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 °C, which enables repairing of damaged interfaces due to cycling by periodical remelting of the cathode material. As a result, an Li-S_9.3I 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.