Advancements in the long-term performance of aqueous lithium-sulfur batteries

Abstract

Yolk-shell sulfur@multi-wall carbon nanotube (S@MWCNT) nanocomposites as the anode for rechargeable aqueous lithium‑sulfur batteries have been successfully prepared by capillary filling assisted with ultrasonication method. The S@MWCNT−40 nanocomposite electrode, totally encapsulated sulfur, represents superior electrochemical performance with an initial discharge capacity up to 668 mA h g−1 and 252 mAh g−1 (on the basis of the sulfur content) at 0.5 A g−1 and 3 A g−1, respectively. This prepared electrode displays high-capacity retention of 91.27 % over 3700 cycles, which is principally attributed to the prevention of aqueous electrolyte from dissolving of long-chain polysulfides and favorable yolk-shell structure that traps polysulfides and balancing sulfur volume changes during lithiation/delithiation. The promising results of this study hold great potential for the future commercialization of rechargeable aqueous lithium‑sulfur batteries.