Highly porous CoFe2O4 nanofibers were synthesized by an electrospinning process followed by a calcination step. The CoFe2O4 nanofibers were highly porous and polycrystalline with an average diameter of 223 nm and a high aspect ratio. A lithium ion battery with its anode fabricated from the electrospun CoFe2O4 nanofibers was developed. The battery exhibited a specific capacity as high as 660 mAh g(-1) after 100 cycles and a coulombic efficiency of over 95%.