Flexible electrospun carbon nanofibers - Nickel disulfide@carbon nanofibers - Carbon nanofibers sandwich structure as binder-free anode for high performance lithium-ion batteries

People have recently shown increasing interest in wearable and flexible electronics. Due to their high electrical conductivity and flexibility, carbon nanofibers can be utilized for various flexible applications. However, pure carbon nanofibers have low capacity, which makes it challenging to achieve high capacity for flexible applications. Herein, sandwich-like nanofibers- nickel disulfide@carbon nanofibers- carbon nanofibers are obtained through a multi-step electrospinning process to serve as a flexible binder-free anode for lithium-ion batteries. This strategy stabilizes the structure well with two layers of carbon nanofibers, effectively accelerating the Li+diffusion + diffusion and promoting the electrolyte infiltration. Accordingly, the electrode exhibits a discharge capacity of 551.8 mAh g(-1) at 0.1 A g(-1) after 100 cycles and achieves a discharge capacity of 523.8 mAh g(-1) at 1 A g(-1) after 1000 cycles, demonstrating excellent cyclic stability and high capacity for Li+ storage. The kinetic analysis also reveals that the sandwich structure provides a higher capacity contribution. This work introduces a novel approach for creating flexible binder-free anodes with high performance, effectively expanding the application of sulfides through electrospinning.