▎ 摘　　要

NOVELTY - Graphene nanofiber material is claimed. The graphene nanofiber material has diameter of 100-900 nm and length of greater than or equal to 10 μm. USE - The graphene nanofiber material is useful as cathode for potassium-ion batteries and nanofiber sensors (claimed). ADVANTAGE - The graphene nanofiber material: ensures the electrolyte fills large pores between graphene nanofibers to form ion channels, which reduces diffusion distance and resistance of ions inside the electrode, and thus improves specific capacity and rate performance of potassium-ion battery. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of graphene nanofiber material. The method utilizes spinnable polymer solution as outer fluid and graphene oxide dispersion as inner fluid; and reducing agent for reduction reaction.