Metal–organic framework-derived porous CoFe2O4/carbon composite nanofibers for high-rate lithium storage

Abstract

In this study, porous CoFe₂O₄/carbon composite nanofibers with metal–organic framework (MOF) structures were prepared by electrospinning and in situ growth followed by annealing. CoFe₂O₄ particles derived from Prussian blue analogues (PBAs) were firmly anchored onto highly conductive carbon nanofibers by tuning the growth time, generating the sturdy construction and prominent conductivity of CFO@C-24 with a large specific surface area, stable fibrous morphology and MOF structure integrity. Owing to these structural merits, more active sites are provided with accelerated electron/Li-ion transport when the nanofiber is applied as an anode in lithium-ion batteries. A high initial discharge/charge capacity of 1400/1328 mA h g⁻¹ at 0.1 A g⁻¹, a considerable reversible discharge/charge capacity of 623/598 mA h g⁻¹after 400 cycles at 1 A g⁻¹ and an excellent rate performance of 585 mA h g⁻¹ at 1.5 A g⁻¹ are presented. Specific capacities of 1166, 1059, 861, 742 and 585 mA h g⁻¹ of CFO@C-24 are achieved at multiple current densities of 0.1, 0.2, 0.5, 1 and 1.5 A g⁻¹, respectively, and the discharge specific capacity is able to resume to 1035 mA h g⁻¹ when returned to 0.1 A g⁻¹. Upon assembling into full cells, considerable capacitance and rate performance are delivered and a series of LED bulbs can be lit to demonstrate its potential in real applications.