Abstract

Lithium–sulfur batteries undergo solid–liquid–solid phase transitions based on a dissolution–deposition reaction mechanism. To effectively suppress the shuttling of soluble polysulfides, catalysts should be incorporated into the cathode to enhance both the adsorption and conversion processes. The formation of a triphasic interface among the catalyst, conductive material, and electrolyte plays a key role in facilitating these reactions. In this study, a composite catalyst (Sn@NBGNs-CNTs), consisting of metallic tin microparticles anchored on nitrogen and boron co-doped graphene nanosheets and partially exfoliated carbon nanotubes, is synthesized as a sulfur host via a simple method. This structure effectively anchors polysulfides at the interface and provided abundant active sites to accelerate redox reaction kinetics. As a result, it facilitated charge transfer and polysulfide transport at the interface, leading to an increase in the nucleation–growth rate constants of Li2S as determined using the critical deposition voltage from the potentiostatic intermittent titration technique. Consequently, the electrode exhibits excellent cycling stability, retaining 93% of its initial capacity after 350 cycles at 1 C with an extremely low-capacity decay rate of 0.003% per cycle.

DOI: 10.1002/smll.202503534 

LINK: https://doi.org/10.1002/smll.202503534