N-doped CoSb@C nanofibers as a self-supporting anode for high-performance K-ion and Na-ion batteries

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