Multi-Pleated Alkalized Ti3C2Tx MXene-Based Sandwich-Like Structure Composite Nanofibers for High-Performance Sodium/Lithium Storage

The volume expansion of CoFe2O4 anode poses a significant challenge in the commercial application of lithium/sodium-ion batteries (LIBs/SIBs). However, metal-organic-frameworks (MOF) offer superior construction of heterostructures with refined interfacial interactions and lower ion diffusion barriers in Li/Na storage. In this study, the CoFe2O4@carbon nanofibers derived from MOF are produced through electrospinning, in situ growth followed by calcination, which are then confined within an MXene-confined MOF-derived porous CoFe2O4@carbon composite architecture under alkali treatment. The CoFe2O4 nanofibers anchor on the alkalized MXene that is decorated with the NaOH solution to form a multi-pleated structure. The sandwich-like structure of the composite effectively alleviates the volume expansion and shortens the Li/Na-ion diffusion path, which displays high capacity and outstanding rate performance as anode materials for LIBs/SIBs. As a consequence, the obtained CoFe2O4@carbon@alkalized MXene composite anode shows satisfied rate performance at current density of 10 A g(-1) for LIBs (318 mAh center dot g(-1)) and 5 A g(-1) for SIBs (149 mAh g(-1)). The excellent cycling performance is further demonstrated at a high current density, where it maintains a discharge capacity of 807 mAh g(-1) at 2 A g(-1) after 400 cycles for LIBs and 130 mAh g(-1) at 1 A g(-1) even after 1000 cycles for SIBs.

Automated summary

The study presents the synthesis of CoFe2O4@carbon@alkalized MXene composite anode with a sandwich-like structure, which effectively mitigates the volume expansion and shortens the Li/Na-ion diffusion path. The composite exhibits high capacity, outstanding rate performance, and excellent cycling stability, making it promising for use in LIBs/SIBs.