Dynamic Multistage Coupling of FeS2/S Enables Ultrahigh Reversible Na–S Batteries. (20th November 2022)

• Record Type: Journal Article
• Authors: Ma, Cunshuang; Wang, Xiang; Lan, Jiaqi; Zhang, Jiyu; Song, Keming; Chen, Jiacheng; Ge, Junmin; Chen, Weihua
• Is Part Of: Advanced functional materials. Volume 33:Number 5(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-11-20
• Subjects: cycling stability -- dynamic multistage coupling -- reversibility -- sodium–sulfur batteries -- sustainability; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.202211821
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: The fundamental challenges that coexisted around sulfur cathode energy storage systems, are the severe polysulfide dissolution and low reactivity resulting in poor reversibility and short cycle life, specifically, in inexpensive sodium ion batteries. Herein, the solution‐processed synthesis of ultra‐high intimate contacted FeS2 /S architecture is reported and evolution of the dynamic multistage coupling between the FeS2 and S in sodium–sulfur batteries is revealed. Atomic visualization and in situ spectroscopy conclude that: Nax FeS2 (0 8 to Na2 S4 to Na2 S2 /Na2 S; simultaneously, the presence of Na2 S2 /Na2 S traps the continuous growth of iron grains during continuously discharging to 0.4 V, thereby boosting the reversibility and high capacity. Moreover, the density functional theory further analyses the unique coupling effect of Na2 Sx with different intermediate states of FeS2 . The electrode with unique structure and dynamic coupling exhibits outstanding cycle reversibility and extremely long life, which delivers a reversible capacity of 860 mAh g −1 after 1000 cycles with no capacity decay at 0.5 A g −1 . Even under a practical areal capacity of 4 mAh cm −2, it still shows pretty‐well cycling stability. Abstract : A novel dynamic multistage coupling mechanism is proposed to enable ultrahigh reversible Na–S batteries, which not only provide low cost and sustainable sulfur cathode, but also give insight into effective coupling and structural engineering to improve electrode reversibility.