In the era of sustainable and clean transportation, electric vehicles are the key to usher. Among carbonaceous materials, carbon nanofibers are inexpensive catalyst that have proven to be high capacity anode material for batteries. In this work, we propose a flexible anode with high electrochemical performance for sodium ion batteries. In this article, we report a porous flexible anode based on copper doped carbon nanofibers grown on activated carbon cloth for sodium ion batteries by chemical vapor deposition methods. It exhibits outstanding high reversible capacity of 462.4 mAg−1 at 100 mAg−1 current density even after 700 cycles. This outstanding performance is due to copper incorporated in the carbon nanofibers framework which enhances the reversible intercalation/de-intercalation of sodium ions during charging–discharging cycles.