First-Principles Investigation of Lithium Polysulfide Structure and Behavior in Solution Academic Article uri icon

abstract

  • 2017 American Chemical Society. The lithium-sulfur battery is a promising next generation energy storage technology that could meet the demands of modern society with a theoretical specific energy near 2500 W h kg-1. However, this battery chemistry faces unique problems such as the parasitic polysulfide shuttle reaction, which hinders battery performance severely. This shuttle phenomenon is caused by solubilities of intermediate reaction products in the electrolyte during the reduction chemistry of the battery. With molecular simulation and computational chemistry tools, we studied the thermodynamics, solvation structure, and dynamics of the long-chain lithium polysulfide species Li2S6 and Li2S8 in dimethoxyethane and 1,3-dioxolane to gain a deeper fundamental understanding of this process. We determined the structure of the first solvation shell for Li+ as well as those of Li2S6, Li2S8 closed, and Li2S8 linear in pure solvents and solvents with extra Li+ added. The lithium polysulfide species were found not to favor dissociation and would most likely exist as fully lithiated species in solution.

published proceedings

  • The Journal of Physical Chemistry C

author list (cited authors)

  • Kamphaus, E. P., & Balbuena, P. B.

citation count

  • 41

complete list of authors

  • Kamphaus, Ethan P||Balbuena, Perla B

publication date

  • October 2017