Electronic redistribution and fast delivery enabled by Co0.5Ni0.5Te2 grafting 3D MXene heterostructure for accelerating High-Durability sulfur redox kinetics

Abstract

Lithium-sulfur (Li-S) batteries are regarded as the most commercially viable energy storage system, but the severe shuttling behavior and sluggish reaction kinetics hinder cycling stability and lifespan. Herein, a brand-new catalytic 3D Co0.5Ni0.5Te2/MXene heterostructure is constructed by uniformly grafting bimetallic telluride nanoparticles onto the MXene nanosheets, inhibiting the restacking of MXene nanosheets. Noticeably, bimetallic elements (Ni/Co) are crosslinking agents that synergistically fulfil and regulate 3D macroporous structure, thus enriching sulfophilic and lithiophilic interactions. The generated 3D porous Co0.5Ni0.5Te2/MXene heterostructure exhibits abundant polar active sites, enhances the chemical adsorption of polysulfides, reduces the transform energy barrier of redox reactions, and provides an accelerated pump for rapid Li+ diffusion at hetero-interface, as sufficient studied by performance analysis, theoretical calculations, and in-situ Raman. Resultantly, the Co0.5Ni0.5Te2/MXene-based batteries exhibit excellent cyclability with a minimum decay ratio of 0.0227 % per cycle during 500 cycles at 1 C, realizing an appealing areal capacity of 8.46 mAh cm−2 even with a high sulfur loading (9.21 mg cm−2) and a lean electrolyte/sulfur ratio (E/S = 6.2 µL mg−1). This work provides an elaborate designed strategy and mechanism insights for simultaneously blocking polysulfides shuttling and enhancing conversion kinetics in Li–S batteries.