Tethering and Catalyzing Lithium Polysulfides in the Cathode to Improve Lithium-Sulfur Battery Lifetime, Energy, & Power
Authors: Chmiola John , Dunlap Nathan , Juran Taylor , Albano Fabio 
Published: December 2024

Lithium-sulfur has been identified as one of the most promising lithium battery chemistries to achieve performance requirements that enable next-generation electrified applications, such as satellite miniaturization and long duration electrified aviation, with a completely U.S.-centric supply-chain [1] . In general, the dissolution and shuttling of intermediate lithium polysulfide (Li2Sx, 4 < x < 8) phases in current- and prior-generation Li-S batteries have limited sulfur utilization (<60%) and led to rapid lifetime degradation [2] . Substantial progress has occurred in C/S composites with sulfur utilization exceeding 60% using various sulfur dispersion and carbon support selection [3] [4] , though commercialization has been fraught with difficulties.

NantG Power is pursuing novel routes to overcome many of the cell-scaling issues with the use of carbon substrate materials modified with sub-nanometer thick catalyst coatings to both accelerate the Solid -> Liquid and Liquid -> Solid phase transformations, as well as act as polar tethering sites for polysulfides. ALD has been shown to improve cathode stability in traditional Li-ion [5] and has been used to cap traditional C/S composite particles and electrodes [6] .

These coatings, prepared with powder atomic-layer deposition (ALD), immobilize the intermediate polysulfides while simultaneously catalyzing their otherwise sluggish reaction kinetics of the multi-phase reactions. With this method, long-term sulfur utilization above 60% can be demonstrated in multi-Ah cells with >5mg/cm2/>60% sulfur loading and E:S < 5, exceeding 400 Wh/kg. This talk will outline a combination of computational modeling approaches (MD, AIMD, DFT, etc.) that predicts the energetic and lattice matching of highly disordered, sub nanometer ALD coatings coupled with electrochemical/chemical/physical interrogation and 1Ah test cell builds to highlight the promise of this reasonably novel direction.

References:

[1] Z. W. Seh, Y. Sun, Q. Zhang, and Y. Cui, “Designing high-energy lithium-sulfur batteries,” Chemical Society Reviews, vol. 45, no. 20. 2016. doi: 10.1039/c5cs00410a.

[2] L. Peng et al., “A fundamental look at electrocatalytic sulfur reduction reaction,” Nat Catal, vol. 3, no. 9, 2020, doi: 10.1038/s41929-020-0498-x.

[3] M. K. Song, Y. Zhang, and E. J. Cairns, “A long-life, high-rate lithium/sulfur cell: A multifaceted approach to enhancing cell performance,” Nano Lett, vol. 13, no. 12, 2013, doi: 10.1021/nl402793z.

[4] Y. Hwa et al., “Three-Dimensionally Aligned Sulfur Electrodes by Directional Freeze Tape Casting,” Nano Lett, vol. 19, no. 7, 2019, doi: 10.1021/acs.nanolett.9b01805.

[5] D. M. King, J. E. Trevey, P. R. Lichty, S.-J. Cho, K. Dahlberg, and F. Albano, “Low-Cost Manufacturing of Safe, Long-Life Battery Materials Using Atomic Layer Deposition,” ECS Meeting Abstracts, vol. MA2016-03, no. 2, 2016, doi: 10.1149/ma2016-03/2/241.

[6] B. Yan et al., “A review of atomic layer deposition providing high performance lithium sulfur batteries,” Journal of Power Sources, vol. 338. 2017. doi: 10.1016/j.jpowsour.2016.10.097.