N-Doped CoSb@C Nanofibers as Self-Supporting Anode for High-Performance K-Ion and Na-Ion Batteries

Herein, the preparation of CoSb nanoparticles embedded in carbon nanofibers with raised surface (N-doped CoSb@C nanofibers) via electrospinning method is firstly reported. The distinct structure facilitates pseudocapacitive behaviors, which is the key to obtain fast kinetics and long cycleability. N and Co elements can not only optimize the electronic configuration, but also buffer volume changes of material. For potassium-ion batteries, the capacity maintains 250 mA h g-1 after 500 cycles at 1 A g-1, for sodium-ion batteries, the capacity retains 413 mA h g-1 after 1000 cycles at 1 A g-1. This work makes great contribution to explore high-capacity anodes for practical potassium-ion batteries and sodium-ion batteries.