Regulating polysulfide conversion and Lithium deposition by hetero-interfacing enable multifunctional separator for highly efficient Lithium-sulfur batteries.

Abstract

Developing highly efficient electrocatalysts to effectively address redox kinetics and the shuttle effect in lithium‑sulfur (Li-S) batteries remains a formidable challenge. Herein, we elaborately engineer an novel heterostructures electrocatalysts with ultra-thin Nickel hydroxide (Ni(OH)₂) nanosheets anchored in a graphene mesh (rGO@Ni(OH)₂) via a general electrostatic self-assembly strategy. This configuration can function as a highly conductive network and offer abundant active sites and catalytic surfaces. Extensive kinetic techniques combined with a convergence of density functional theory (DFT) calculations collectively decipher that interpenetrated nano-hetero-interfacing of vertically oriented Ni(OH)₂ nanosheets coupling of graphene mesh largely trigger a redistribution of electrons due to the strong interfacial interactions, resulting in more optimized adsorption energies of the polysulfide (LiPSs), and significantly promoting the LiPSs bidirectional catalytic transformation kinetics. Consequently, the rGO@Ni(OH)₂ integrated separator achieves consolidated uniform lithium deposition (surprisingly stable cycle at 0.5 mA cm^-2 for up to 1000 h). The cell equipped with rGO@Ni(OH)₂ separator exhibits a high initial capacity of 1318 mAh g^-1 at 0.1C and exceptional durability. More encouragingly, the rGO@Ni(OH)₂ based pouch cells sustain a promising discharge capacity of 485 mAh g^-1 (257 mAh) following 100 cycles at 0.2C. This research significantly advances the comprehension of the catalysis mechanism with nano-heterointerfaces in modulating sulfur redox pathways.