High-capacity and long-life CoO/C composite nanofibers as anode materials for lithium-ion batteries

Owing to its analogous conversion reaction mechanism and the same cobalt redox center with Co₃O₄, CoO was investigated as a high-capacity anode material for lithium-ion batteries in this study. The composite nanofibers, which were constructed by ultrafine CoO nanocrystals (∼5 nm) uniformly embedded in carbon matrix, were prepared by a simple electrospinning technique followed by high-temperature calcination. The resulting CoO/C composite nanofibers exhibited exceptional electrochemical performance. Notably, the CoO/C composite nanofiber prepared with 0.8 g of PVP (denoted as CoO/MC) delivered a charge capacity of 1147 mA h g^-1 at 100 mA g^-1 over 400 cycles. At a high current density of 1000 mA g^-1, its charge capacity attained 578.7 mA h g^-1, reaching 49.6% of that at 100 mA g^-1. Kinetic analysis revealed that the diffusion-controlled contribution constituted a significant portion of the total capacity for the CoO/MC electrode. The excellent electrochemical performance of CoO/C composite nanofibers was related to inherent lithium storage property of CoO and their unique nanoarchitecture originated from a reasonable synthesis strategy. This work provides a new conceive to improve the lithium storage performance of metal oxide-based anode materials.