Postdoctoral Research Fellow, University of Texas at Austin
Email address: [email protected]
Presented: April 1 and 2, 2021
“Dynamics of lithium deposition in lithium-sulfur batteries and strategies for enhancing lithium cycling efficiencies”
The lithium-sulfur (Li-S) couple is one of the most promising chemistries for realizing the next generation of high energy density rechargeable batteries. Over the last decade, there have been concerted efforts towards solving the issues with the sulfur cathode. However, maintaining reasonable cycle life in practically relevant cell designs, with a limited lithium inventory and lean electrolyte supply, has proven quite challenging. This can be primarily attributed to the poor reversibility of the lithium-metal anode, which undergoes high-surface area mossy growth mechanisms and severe parasitic side reactions with the electrolyte during plating and stripping. Solving this challenge is key to Li-S batteries realizing their commercial viability. Furthermore, lithium deposition in the Li-S system is uniquely convoluted by the presence of soluble polysulfide intermediates in the liquid electrolyte. In this presentation, the anode-free full cell configuration is developed as an effective and reliable framework for investigating the dynamics of lithium deposition in Li-S batteries. This framework is employed to shed light on the mechanisms underlying rapid lithium degradation during cell operation. The interplay between the dynamically evolving lithium-electrolyte interfacial chemistry and the rate of lithium inventory depletion with cycling is delineated. A generalized strategy involving molecular-scale engineering of polysulfide species and exploiting the intrinsic shuttle effect is developed for improving lithium cycling efficiencies by forming a stable and passivating interfacial layer on the lithium surface. Excellent cyclability is demonstrated under realistic limited-lithium and lean-electrolyte conditions. Finally, an outlook for the further development of commercially viable Li-S batteries is provided.
Sanjay Nanda, Postdoctoral Research Fellow, University of Texas at Austin
Sanjay Nanda is currently a postdoctoral research fellow in the group of Prof. Arumugam Manthiram at the Texas Materials Institute. He received his Ph.D. (2020) degree in Materials Science and Engineering from the University of Texas at Austin and his M.Phil. (2014) degree in Nanotechnology from the University of Cambridge. His research is focused on devising strategies for stabilizing lithium deposition in lithium–sulfur batteries and lithium-NMC batteries and understanding the degradation mechanisms that underlie the failure of lithium‐metal anodes.