Regulating Li+ migration and Li2S deposition by metal-organic framework-derived Co4S3-embedded carbon nanoarrays for durable lithium-sulfur batteries

Abstract

The shuttle effect of lithium polysulfides and the uncontrollable deposition of lithium sulfides (Li2S) severely hinder the realization of high-performance lithium-sulfur (Li-S) batteries. Herein, we fabricated a carbon cloth (CC)-based self-supported interlayer (denoted as Co4S3/C@CC), which is covered with Co4S3-embedded porous carbon nanoarrays through a facile two-step method with cobalt-based metal-organic framework (Co-MOF) nanosheets as the template. The interconnected carbon network and the polar Co4S3 nanoparticles in the Co4S3/C@CC interlayer not only effectively suppress the polysulfide shuttle, but also significantly facilitate the lithium ion (Li+) conduction with a considerable Li+ transference number of 0.86. Besides, the rich interfaces between the polar Co4S3 nanoparticles and the conductive carbon substrate serve as reaction sites to accelerate the polysulfide conversion and guide the flower-like growth of Li2S, which ultimately mitigates the interlayer surface passivation and improves the sulfur utilization. Therefore, the Li-S batteries with the Co4S3/C@CC interlayer deliver an excellent rate capacity (368.7 mA h g−1 at 10 C), a stable cycling performance (a low fading rate of 0.045% per cycle over 1400 cycles at 2.0 C), and a high initial areal capacity (4.83 mA h cm−2 at 0.2 C under a sulfur loading of 4.6 mg cm−2). This work provides a perspective on the self-supported catalytic interlayer for the selective Li+ conduction and Li2S regulation toward high-performance Li-S batteries.