Nitrogen and Fluorine Dual Doping of Soft Carbon Nanofibers as Advanced Anode for Potassium Ion Batteries.

Potassium-ion batteries (PIBs) are recognized as promising alternatives for lithium-ion batteries as the next-generation energy storage systems. However, the larger radius of K hinders the K insertion into the conventional carbon electrode and results in sluggish potassiation kinetics and poor cycling stability. Here, nitrogen and fluorine dual doping of soft carbon nanotubes (NFSC) anode are synthesized in one pot, achieving extraordinary electrochemical performance for PIBs.