3D Cotton-Pad-Like Hierarchically Porous Structure Stacked by Hexagonal Highly Graphitized Carbon Nanosheets as Sulfur Immobilizers for Li-S Batteries

Achievement of carbon materials with particular structures, dimensions, and sizes derived from metal organic frameworks (MOFs) with particular morphologies is very crucial for purpose-oriented applications such as Li-S batteries in which little is known about carbon structures from low melting point indium-based MOFs (In-MOFs). Here, we pioneeringly prepared a 3D cotton-pad-like hierarchically porous carbon (CPHPC) structure stacked by hexagonal highly graphitized carbon nanosheets based on In-MOFs synthesized at room temperature, which was demonstrated to be the effective sulfur host for Li-S batteries. The sulfur@CPHPC cathodes exhibit excellent rate performance with reversible capacities of 1349 and 691 mA h g(-1) at 0.2 and 20 C, respectively, and admirable cycling performance with quite low decay rates of 0.033% per cycle for 1000 cycles at 0.5 C and 0.014% per cycle for 3800 cycles at 10 C. The admirable electrochemical performances are ascribed to the superior conductivity resulting from the 3D highly graphitized carbon conductive network, the effective confinements of polysulfides arising from sufficient contact between the carbon host and sulfur, and the high stability of rigid structures stacked by porous nanosheets. This easily achieved unique carbon structure and its derivatives in the form of carbon have a critical role to play in the performances of not only Li-S batteries but also lithium-ion batteries, supercapacitors, catalysis, and chemical absorption.

Automated summary

The research successfully synthesized a 3D cotton-pad-like hierarchically porous carbon structure at room temperature, which exhibited excellent rate performance and cycling stability in Li-S batteries.