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oai:figshare.com:article/34021278 2026-09-29T04:49:42Z category_33464 category_31817 category_32963 category_31973 portal_1005 item_type_6 month_year_09_2026

High-Efficiency Lithium Sulfur Cells With Suppressed Polysulfide Solubility Using a Cost-Effective Ammonium-Based Ionic Liquid Electrolyte Ajit Kumar (13057170) F Nti (15793457) P Kumari (13383897) M Maleki (13898406) S Rowlands (16473498) PM Bayley (22268551) Robert Kerr (13078713) Anthony Somers (13059393) Maria Forsyth (13084584) Patrick Howlett (13088661) Materials engineering Chemical sciences Engineering Physical chemistry Science & Technology Physical Sciences Technology Chemistry, Multidisciplinary Chemistry, Physical Nanoscience & Nanotechnology Materials Science, Multidisciplinary Physics, Applied Physics, Condensed Matter Chemistry Science & Technology - Other Topics Materials Science Physics anode chemical engineering dielectric spectroscopy dissolution electrochemistry electrolyte faraday efficiency ionic liquid passivation polysulfide METAL STRATEGIES BATTERIES ANODES 7 Affordable and Clean Energy Lithium–sulfur batteries suffer from polysulfide shuttle (PS) and lithium metal anode instability. We developed a mixed-anion ionic liquid (IL) electrolyte combining N-trimethyl-N-propylammonium bis(fluorosulfonyl)imide (N1113FSI) with LiFSI and LiTFSI, enabling stable lithium metal passivation while suppressing polysulfide dissolution to sub-mM levels. Electrochemical testing demonstrates a specific capacity of 900 mA h g⁻¹ with 70% retention after 300 cycles. Electrochemical impedance spectroscopy (EIS) reveals a substantial reduction in charge-transfer resistance post-lithiation and stable impedance during extended cycling. Raman spectroscopy confirms effective polysulfide suppression. Notably, cell performance is insensitive to the electrolyte-to-sulfur ratio (10–45 µL mg⁻¹), in contrast to conventional ether-based electrolytes. Depth-resolved x-ray photoelectron spectroscopy (XPS) reveals that N1113FSI forms abundant LiF through efficient anion reduction, yielding a dense, inorganic-rich solid-electrolyte interphase (SEI). In contrast, P111i4FSI retains incompletely reduced anions and exhibits diminished LiF, demonstrating cation-dependent control of SEI chemistry. The N1113FSI interphase contains higher levels of LiF, Li-sulfide, oxidized sulfur, and inorganic oxygen species, which correlate with superior cycling stability. Compared to P111i4FSI, N1113FSI achieves higher discharge capacity (DC), faster Coulombic efficiency (CE) stabilization, and sustained reversibility. Tailored IL design effectively suppresses polysulfide solubility and engineers efficient SEI chemistry, mitigating shuttle effects and enabling stable Li–S operation across varying electrolyte concentrations. 2026-01-01T00:00:00Z Text Journal contribution 10.26187/deakin.34021278 https://figshare.com/articles/journal_contribution/High-Efficiency_Lithium_Sulfur_Cells_With_Suppressed_Polysulfide_Solubility_Using_a_Cost-Effective_Ammonium-Based_Ionic_Liquid_Electrolyte/34021278 CC BY-NC-ND 4.0