YF3/CoF3 co-doped 1D carbon nanofibers with dual functions of lithium polysulfudes adsorption and efficient catalytic activity as a cathode for high-performance Li-S batteries.

YF 3 /CoF 3 co-doped 1D carbon nanofibers as S host. [Display omitted] Lithium-sulfur (Li-S) batteries have attracted extensive attention in the field of energy storage due to their high energy density and low cost. However, conundrums such as severe polarization, poor cyclic performance originating from shuttle effect of lithium polysulfides and sluggish sulfur redox kinetics are stumbling blocks for their practical application. Herein, a novel sulfur cathode integrating sulfur and polyvinylpyrrolidone(PVP)-derived N -doped porous carbon nanofibers (PCNFs) with embedded CoF 3 and YF 3 nanoparticles are designed and prepared though the electrostatic blowing technology and carbonization process. The unique flexible PCNFs with embedded polar CoF 3 and YF 3 nanoparticles not only offer enough voids for volume expansion to maintain the structural stability during the electrochemical process, but also promote the physical encapsulation and chemical entrapment of all sulfur species. Moreover, the uniform distribution of YF 3 /CoF 3 nanoparticles also can expose more binding active sites to lithium polysulfide and present more catalytic sites to the greatest extent. Therefore, the assembled cells with the prepared cathode exhibited stable performances with an outstanding initial capacity of 1055.2 mAh g−1 and an extended cycling stability of 0.029% per cycle during the 300 cycles at 0.5C. Even at a high sulfur loading of 2.1 mg cm−2, The YF 3 /CoF 3 doped-PCNFs exhibited a high discharge specific capacity of 1038 mAh g−1, and the decay rate is also as low as 0.05% over 1000 cycles. This work shares a convenient and safe strategy for the synthesis of multi-dimension, dual-functional and stable superstructure electrode for advanced Li-S batteries. [ABSTRACT FROM AUTHOR]