Discovery of Dual‐Functional Amorphous Titanium Suboxide to Promote Polysulfide Adsorption and Regulate Sulfide Growth in Li–S Batteries. Issue 22 (5th June 2022)

• Record Type: Journal Article
• Authors: Gueon, Donghee; Yoon, Jisu; Cho, Jinhan; Moon, Jun Hyuk
• Is Part Of: Advanced science. Volume 9:Issue 22(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-06-05
• Subjects: amorphous titanium suboxides -- DFT calculations -- high sulfur loading -- lithium sulfide clustering -- lithium–sulfur batteries; Science -- Periodicals; 505
• DOI: 10.1002/advs.202200958
• Languages: English
• ISSNs: 2198-3844

Abstract

Abstract: Lithium‐sulfur (Li–S) batteries are promising as next‐generation energy storage systems. Adsorbents for sulfide species are favorably applied to the cathode, but this substrate often results in a surface‐passivating lithium sulfide(Li2 S) film with a strong adsorption of Li2 S. Here, an amorphous titanium suboxide (a‐TiOx) is presented that strongly adsorbs lithium polysulfides (Li2 Sx, x < 6) but relatively weakly adsorbs to Li2 S. With these characteristics, the a‐TiOx achieves high conversion of Li2 Sx and high sulfur utilization accompanying the growth of particulate Li2 S. The DFT calculations present a mechanism for particulate growth driven by the promoted diffusion and favorable clustering of Li2 S. The a‐TiOx ‐coated carbon nanotube‐assembled film (CNTF) cathode substrate cell achieves a high discharge capacity equivalent to 90% sulfur utilization at 0.2 C. The cell also delivers a high capacity of 850 mAh g –1 even at the ultra‐high‐speed of 10 C and also exhibits high stability of capacity loss of 0.0226% per cycle up to 500 cycles. The a‐TiOx /CNTF is stacked to achieve a high loading of 7.5 mg S cm –2, achieving a practical areal capacity of 10.1 mAh cm –2 . Abstract : Amorphous titanium suboxide (a‐TiOx ), which strongly adsorbs lithium polysulfides (Li2 Sx, x<6) but relatively weakly to lithium sulfide (Li2 S), is introduced for the cathode of lithium‐sulfur (Li–S) battery. The a‐TiOx substrate cathode achieves a high sulfur utilization rate of 90% at 0.2 C by high conversion of Li2 Sx and growth of particulate Li2 S.