Bi2S3in-situ formed in molten S environment stabilized sulfur cathodes for high-performance lithium-sulfur batteries

•A synchronous approach for S/Bi2S3/C composite cathodes is described.•The in-situ formed Bi2S3 could provide anchoring effect with lithium polysulfides.•Those S/Bi2S3/C composites exhibit good performance in LiS batteries.

S/Bi2S3/C composites have been prepared based on melt strategy at 280 °C starting from metallic bismuth (mp 271.3 °C), excess sulfur powder and porous carbon with different ratio. In the as-prepared composites, the in-situ formed Bi2S3 in molten S environment can homogeneously dispersed in S and carbon. Combining the physical confinement of porous carbon and chemical interaction of the in-situ formed Bi2S3, the dissolution of polysulfides has been well inhibited. Thus, the obtained S/Bi2S3/C composite exhibits good electrochemical performance, which could deliver capacity of ∼825 mAh g−1 at 0.5 C over 400 cycles, with 91% capacity retention and high Coulombic efficiency.

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