Uniform embedding of ultrafine sulfur into well-honeycombed porous graphene frameworks for highly stable Li–S batteries

Abstract

Lithium-sulfur (Li–S) batteries have been recognized as one of the most promising lithium-ion power sources. However, their commercial application is greatly hindered by the incompletely used active materials and unsatisfactory cyclability. Herein, a novel well-honeycombed porous graphene framework (3D-G) was developed using a PMMA-sphere-assisted vacuum filtration method, and used as an advanced sulfur host for enhancing Li–S battery performance. The unique well-honeycombed porous graphene framework not only enhances the electronic conductivity of Li–S cathodes, but also provides numerous active sites for sulfur adsorption. Moreover, the ultrafine sulfur uniformly embedded into the well-honeycombed porous graphene framework increases the utilization of active materials. Benefiting from these synergistic features, 3D-G/S cathodes exhibit excellent electrochemical performance, such as long-cycling stability with a ultra-low capacity fading of 0.099% per cycle over 200 cycles at a high current density, holding great promise for development of practically viable Li–S batteries.