Graphene-Wrapped Sulfur Particles as a Rechargeable Lithium-Sulfur-Battery Cathode Material with High Capacity and Cycling Stability

TL;DR

This paper presents a novel graphene-sulfur composite cathode for lithium-sulfur batteries that achieves high capacity and stability over many cycles by using a specialized coating to accommodate volume changes and trap intermediates.

Contribution

The study introduces a new synthesis method for a graphene-wrapped sulfur composite that enhances capacity and cycling stability in lithium-sulfur batteries.

Findings

Achieved stable specific capacities of ~600mAh/g over 100+ cycles.

Effective trapping of polysulfide intermediates by graphene coating.

Improved accommodation of volume expansion during discharge.

Abstract

We report the synthesis of a graphene-sulfur composite material by wrapping polyethyleneglycol (PEG) coated submicron sulfur particles with mildly oxidized graphene oxide sheets decorated by carbon black nanoparticles. The PEG and graphene coating layers are important to accommodating volume expansion of the coated sulfur particles during discharge, trapping soluble polysulfide intermediates and rendering the sulfur particles electrically conducting. The resulting graphene-sulfur composite showed high and stable specific capacities up to ~600mAh/g over more than 100 cycles, representing a promising cathode material for rechargeable lithium batteries with high energy density.