Features of cycling of lithium-sulfur cells with electrolytes based on sulfolane solutions of LiPF6 and LiBF4

Karaseva E., Khramtsova L., Lobov A., Kuzmina E., EROĞLU PALA D., Kolosnitsyn V.

Journal of Power Sources, cilt.548, 2022 (SCI-Expanded, Scopus)

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 548
  • Basım Tarihi: 2022
  • Doi Numarası: 10.1016/j.jpowsour.2022.231980
  • Dergi Adı: Journal of Power Sources
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, PASCAL, Aerospace Database, Chemical Abstracts Core, Communication Abstracts, INSPEC, Metadex, Pollution Abstracts, Civil Engineering Abstracts
  • Anahtar Kelimeler: Cycling, Electrolyte design, Lithium polysulfide, Lithium salt, Lithium-sulfur cell, Sulfolane
  • Boğaziçi Üniversitesi Adresli: Evet

Özet

In lithium-sulfur batteries, cell design, specifically electrolyte design, has a key impact on the battery performance. Development of sulfolane based electrolytes may grant the use of more available lithium salts such as LiClO4, LiPF6 and LiBF4, which are typically not preferred in lithium-sulfur batteries due to their reactive anions. Herein, in order to assess the reactivity of lithium polysulfides with various dimensions (with different lengths of the polysulfide chain) towards the anions of lithium electrolyte salts, the cycling of lithium-sulfur cells with 1 M solutions of LiPF6, LiBF4, and LiClO4 in sulfolane is studied in a wide (1.5–2.8 V) and narrow (limited) voltage ranges, corresponding to the high-voltage (2.1–2.8 V) and low-voltage (2.3–1.5 V) plateaus on the discharge curves. It is shown that the electrochemical characteristics of lithium-sulfur cells with sulfolane based electrolytes of lithium perchlorate and lithium hexafluorophosphate differ significantly from those for sulfolane electrolyte based on lithium tetrafluoroborate. We believe that these differences are due to the direct chemical interaction of lithium polysulfides with the BF4− anion, which is confirmed by chronopotentiometry, 7Li and 11B NMR spectra, UV–Vis and electrochemical impedance spectroscopy of sulfolane solutions of the studied lithium salts, saturated with lithium polysulfides.