Layered Electrodes Based on 3D Hierarchical Porous Carbon and Conducting Polymers for High-Performance Lithium-Sulfur Batteries

Easy dissolution of polysulfides and low loading of active materials are two major factors that limit the cathode cycling stability and energy density in lithium-sulfur batteries. Herein, 3D hierarchical carbon with abundant pores is used for sulfur encapsulation (S@DHPC), which achieves a high sulfur content of 74 wt% and high sulfur loading of 5.8 mg cm(-2). Importantly, coating the obtained S@DHPC electrode with poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) conducting polymers is found to effectively impede the diffusion of polysulfide species, leading to marked improvement of the cycling stability of the electrode; and the electrode performance increases with an increasing number of the S@DHPC/PEDOT:PSS layer. For a three-layer electrode, at a current density of 2 C, it delivers a discharge capacity of 846 mAh g(-1) in the first cycle and maintains a capacity of 716 mAh g(-1) after 500 cycles, corresponding to a fading rate of only 0.033% cycle(-1). Results from this study suggest that layered electrodes can be exploited as a unique electrode architecture for the fabrication of high-performance lithium-sulfur batteries.