The coupling of metal oxide nanoparticles and electrochemically active polymers has been considered as an effective way to improve the lithium storage performance of individual electrode materials. This work reports an electrospinning process followed by thermal

annealing to produce composite nanofibers of cyclizedpolyacrylonitrile (cPAN) containing Co3O4 nanoparticles (cPAN/Co3O4). The as-prepared cPAN/Co3O4 nanofiber exhibits a porous nanostructure with an average diameter of 85 nm. When used for lithium-ion battery, the cPAN/Co3O4 anode delivers a reversible specific capacity as high as 997.6 mA h g-1 at 0.1 A g-1, and still maintains 396.5 mA h g-1 at 1.0 A g-1. Meanwhile, the cPAN/Co3O4 anode shows good cycling stability with a retention of 81% capacity after running 50 cycles at 0.1 A g-1. The electrochemical performance of cPAN/Co3O4 significantly outperforms its individual counterparts of cPAN and Co3O4