A facile strategy for Co₃O₄/Co nanoparticles encapsulated in porous N-doped carbon nanofibers towards enhanced lithium storage performance

Well-designed nano-hybrids are of great interests in the field of electrode materials for rechargeable Li ion batteries, because they promise new hope to solve the current key issues. In this work, Co₃O₄ and Co nanoparticles were loaded onto the porous N-doped carbon nanofibers by a simple and scalable electrospinning route, followed by multiple calcinations. XRD, XPS, SEM, and TEM were employed to investigate the chemical composition and microstructure of the obtained products. When evaluated as an anode material, the as-prepared Co₃O₄/Co/N-doped porous carbon nanofibers nanostructured composites offer excellent battery performance in terms of relative high reversible capacity, long cyclic lifespan and rate performances. In particularly, the reversible capacities could remain at 663 mAh/g and 448 mAh/g at high current densities of 500 mA/g and 1000 mA/g after 350 cycles, respectively. The superior lithium storage performance is ascribed to the high temperature induced metal Co, well-dispersed Co₃O₄/Co nanoparticles and the N-doped porous carbon nanofibers. Furthermore, this strategy of designing nano-hybrids can also be applied to other transition metal oxides as anodes.