An Electrospun Core-Shell Nanofiber Web as a High-Performance Cathode for Iron Disulfide-Based Rechargeable Lithium Batteries

FeS₂ /C core-shell nanofiber webs were synthesized for the first time by a unique synthesis strategy that couples electrospinning and carbon coating of the nanofibers with sucrose. The design of the one-dimensional core-shell morphology was found to be greatly beneficial for accommodating the volume changes encountered during cycling, to induce shorter lithium ion diffusion pathways in the electrode, and to prevent sulfur dissolution during cycling. A high discharge capacity of 545 mAh g^-1 was retained after 500 cycles at 1 C, exhibiting excellent stable cycling performance with 98.8 % capacity retention at the last cycle. High specific capacities of 854 mAh g^-1 , 518 mAh g^-1 , and 208 mAh g^-1 were obtained at 0.1 C, 1 C, and 10 C rates, respectively, demonstrating the exceptional rate capability of this nanofiber web cathode.