Batteries (Aug 2023)

Dual-Functional Electrolyte Additive for Lithium–Sulfur Batteries Limits Lithium Dendrite Formation and Increases Sulfur Utilization Rate

  • Chang Liu,
  • Huiyuan Wu,
  • Jiachun Wu,
  • Yinglin Xiao,
  • Yonghong Deng

DOI
https://doi.org/10.3390/batteries9090444
Journal volume & issue
Vol. 9, no. 9
p. 444

Abstract

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Lithium–sulfur batteries (LSBs) have received great attention as promising candidates for next-generation energy-storage systems due to their high theoretical energy density. However, their practical energy density is limited by a large electrolyte-to-sulfur (E/S) ratio (>10 µL electrolyte/mg s), and their cycle performance encounters challenges from electrode passivation and Li dendrite formation. In this work, a dual-functional electrolyte additive of tetraethylammonium nitrate (TEAN) is presented to address these issues. NO3− as a high-donor-number (DN) salt anion can promote polysulfide dissolution, increase sulfur utilization, and alleviate electrode passivation. The tetraethylammonium cation can adsorb around Li protrusions to form a lithiophobic protective layer to inhibit the formation of Li dendrites. TEAN LSBs show improving capacity, cycling stability, and higher coulombic efficiency under lean electrolyte (5 μL electrolyte/mg s) conditions.

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