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Conductive supports could improve the electrical conductivity of the electrode in lithium–sulfur (Li–S) batteries but suffer from the shuttle effect originated from the polysulfide dissolution, while the hydrophilic metal oxides could avoid the shuttle effect but with poor conductivity. Herein, a facile approach was developed to fabricate hierarchically porous tin oxide (SnO2) nanoparticle-anchored tubular polypyrrole (T-PPy) as a sulfur host, in order to integrate the advantages of conductive supports and metal oxides but overcome their shortcomings. In the unique structure, the T-PPy nanotubes acted as a conductive network to not only improve the electrical conductivity of cathodes but also accommodate the volume expansion of the sulfur cathode during cycling as well as relatively confine the polysulfide diffusion, while the SnO2 nanoparticles served as a high-efficient polysulfide trap to mitigate the shuttle effect due to the chemical bond between SnO2 and polysulfides. Moreover, the hierarchically porous structure and therefore large surface area of the proposed S/(T-PPy)@SnO2 cathode were favorable for the accommodation of sulfur and lithium sulfides. Consequently, S/(T-PPy)@SnO2 with 64.7% sulfur mass content exhibited excellent cyclic stability with a decay rate of only 0.05% per cycle along with 500 cycles at 1 C, rate capability of 383.7 mA h/g at 5 C, and Coulombic efficiency above 90%, outstanding among most of the reported PPy-based sulfur cathodes and PPy-based ternary sulfur cathodes.

Well-defined core-shell structured coaxial sulfur/polypyrrole tubular nanocomposites, polypyrrole nanotubes wrapped by uniform rough sulfur layers, were fabricated as Li-S battery cathodes via a facile one-pot method. In the designed structure, the polypyrrole backbone can facilitate the charge transport and also restrain the soluble polysulfide diffusion, while the active sulfur layer can efficiently react with Li+ assisted by the PPy nanotubes, and the lithium polysulfides can be massively trapped by the PPy nanotubes during charge-discharge processes. The as-prepared coaxial sulfur/polypyrrole tubular nanocomposites with a sulfur loading of 53.3% exhibited a high initial discharge specific capacity of 1117 mA h g-1 with a remarkable cycling stability, retaining 692 mA h g-1 and 525 mA h g-1 after 200 cycles at a current density of 0.2C and 1C, respectively. Moreover, they expressed an excellent rate capability performance, maintaining 470 mA h g-1 at a high current density of 2C.