Highly-flexible 3D Li2S/graphene cathode for high-performance lithium sulfur batteries

Three-dimensional Li2S/graphene hierarchical architecture (3DLG) is synthesized with a facile infiltration method. Highly-crystalline Li2S nanoparticles are deposited homogenously into three-dimensional graphene foam (3DGF) network grown by chemical vapor deposition (CVD), resulting in 3DLG with high surface area, porosity, flexibility and conductivity. The 3DLG is employed as flexible, free-standing and binder-free cathode without metallic current collectors or conducting additives. Due to the unique structure, the 3DLG exhibits a high discharge capacity of 894.7 mAh g(-1) at 0.1 degrees C, a high capacity retention of 87.7% after 300 cycles at 0.2 degrees C, and the high-rate capacity up to 4 degrees C reaches 598.6 mAh g(-1). The cyclic performance is record-breaking compared to the previous reports on free-standing graphene-Li2S cathodes. Flexible lithium-sulfur batteries based on the high-capacity 3DLG cathode have promising application potentials in flexible electronics, electrical vehicles, etc. (C) 2016 Elsevier B.V. All rights reserved.