Graphene and polydopamine double-wrapped porous carbon-sulfur cathode materials for lithium-sulfur batteries with high capacity and cycling stability

• Published in: Ionics 2017-12, Vol.23 (12), p.3329-3337
• Main Authors: Dong, Yuan, He, Run-Tian, Fan, Li-Zhen
• Format: Article
• Language: English
• Subjects: Carbon; Cathodes; Chemistry; Chemistry and Materials Science; Condensed Matter Physics; Cycles; Electrochemistry; Electrode materials; Electrodes; Electron transfer; Energy Storage; Graphene; Lithium; Lithium sulfur batteries; Optical and Electronic Materials; Original Paper; Polysulfides; Porous materials; Rechargeable batteries; Renewable and Green Energy; Stability; Structural hierarchy; Synergistic effect
• ISSN: 0947-7047; 1862-0760
• DOI: 10.1007/s11581-017-2138-2

Rechargeable lithium-sulfur batteries are deemed to be a promising energy supply to next-generation high energy power system, yet dissolution of lithium polysulfides in the electrolyte leads to poor cycling performance. Here, we report an approach to assemble graphene and polydopamine double-wrapped porous carbon/sulfur (GN-PD-PC-S) for lithium-sulfur batteries. Remarkably, the double-wrapping graphene and polydopamine further help confine the sulfur and polysulfides inside the mesopores and micropores of porous carbon. Moreover, the hierarchical porous structures provide a conductive network for electron transfer and facilitate the effective accommodation of the volume change of sulfur. The GN-PD-PC-S cathode presents an excellent cycling stability of 821 mAh g −1 after 100 cycles, with a favorable high-rate capability of 496 mAh g −1 at a current density of 2 A g −1 . Our results indicate the importance of chemically synergistic effect of polymer and carbon in the electrode system for achieving high-performance electrodes in rechargeable lithium-sulfur batteries.