Packing Sulfur Species by Phosphorene‐Derived Catalytic Interface for Electrolyte‐Lean Lithium–Sulfur Batteries

Abstract

The practical application of lithium-sulfur batteries is hampered by the sluggish redox reaction kinetics and severe lithium polysulfide (LiPS) migration, especially under high sulfur loading and lean electrolyte scenarios. Strategies to catalyze the sulfur liquid/solid conversion within a "hermetic" nano-container have been proposed, where the LiPS migration and sluggish reaction kinetics can be simultaneously addressed. Herein, to realize rapid LiPS conversion and slow LiPS migration, the sulfur species are packed by a hermetic catalytic interface, constructed by the phosphorene/graphene heterostructure. The 2D phosphorene/graphene stacking has two unique benefits: 1) a direct electron transfer avoiding any insulating media, resulting in an exceptional catalytic effect on LiPS conversion; ii) favorable charge rearrangement that enhances chemisorption toward LiPS and limits LiPS crossover. The proposed highly flexible hermetic interface with strong van der Waals serves as a bifunctional nano-container to pack sulfur species and promote sulfur redox reactions, which gives rise to excellent battery performances: a high areal capacity of 5.57 mAh cm −2 under a low electrolyte/sulfur ratio of 5.7 mL g −1 . This work affords a coupling strategy that embraces interfacial and structural engineering to promote kinetic reactions of sulfur conversions under electrolyte-lean conditions.

Realizing High Utilization of High-Mass-Loading Sulfur Cathode via Electrode Nanopore Regulation

“…Even at an E/AM value of ∼2.5 μL mg –1 , it displayed a very high areal capacity of 10.9 mAh cm –2 at 0.75 mA cm –2 with the specific capacity of 1211.1 mAh g –1 and high S utilization of 72.4%, and stable cycling performance (Figure f and Figure S22). As a result, a high E g of 520 Wh kg –1 and an E v of 1635 Wh L –1 were realized for the as-achieved chunky S/graphene particle electrode (calculated based on the total mass of active material, binder, conductive additive, and electrolyte), representing a very high level compared with most reported S electrodes (Figure g). − …”

Electrochemical Exfoliation of Two‐Dimensional Phosphorene Sheets and its Energy Application

“…[58,59] Tang et al fabricated phosphorene-derived heterostructure as a robust and highly catalytic sulfur container to pack sulfur species (Figure 6d). [60] This heterostructure not only induces a direct electron transfer avoiding any insulating media, resulting in an exceptional catalytic effect on lithium polysulfide conversion, but also impels favorable charge rearrangement that enhances chemisorption toward lithium polysulfide and limits lithium polysulfide shuttle (Figure 6e). Under a lean-electrolyte condition, such unique characteristics enable exceptional battery efficiency.…”

A N-Rich porous carbon nanocube anchored with Co/Fe dual atoms: an efficient bifunctional catalytic host for Li–S batteries

“…Peaks 2.30 V and 2.05 V are related to the reduction S 8 to Li 2 S 4 and following conversion from Li 2 S 4 to Li 2 S, and anodic peaks at 2.31 and 2.4 V are attributed to the oxidation of Li 2 S to Li 2 S 4 and Li 2 S 4 to S 8 , which suggests that the Co and Fe atom catalysts can promote the long-chain and short-chain polysulfide conversion reaction. 65,66 While anchoring Co and Fe atoms on NC, positive shifts in the cathodic peaks and negative shifts in the anodic peaks were generated, which illustrates the enhanced catalytic activity of the S@CoFe-NC on the conversion reaction of the sulfide species. When the symmetric cells comprising of two same NC, Co-NC, Fe-NC and CoFe-NC electrodes using 0.5 M Li 2 S 6 -containing electrolyte were employed, a similar result could be revealed, that is, fast reaction kinetics and high redox charge storage capacity of the CoFe-NC electrode (Fig.…”