Flexible Nb₂O₅/MoS₂/Carbon Nanofiber Paper Anodes for Sodium-Ion Batteries

Abstract

The\ndesign and fabrication of flexible anodes are crucial for advancing\nflexible sodium-ion batteries (SIBs). Electrospun carbon nanofiber\n(CNFs) composite electrodes are expected to be an effective solution.\nHere, by beneficial introduction of appropriate amount of Nb₂O₅ nanoparticles into pure CNFs, the problem of brittle\nstress concentration in CNFs has been significantly mitigated, providing\ngood flexible mechanical stability. However, both Nb₂O₅ and pure CNFs face the issue of relatively low theoretical\ncapacity, which limits their application in SIBs. In order to address\nthis issue, a cattail-like flexible fiber paper anode composed of\nNb₂O₅/MoS₂/C CNFs is developed and\nfabricated in this study. With the aid of synergetic effects, it delivers\na specific capacity of 302.68 mA h g^–1 at 0.1 A\ng^–1 higher than that of Nb₂O₅ CNFs (156.14 mA h g^–1). Additionally, it shows\nthe highest reversible specific capacity of 266.43 mA h g^–1 after 100 cycles at 0.1 A g^–1 higher than the\ncontrasted Nb₂O₅ (154.09 mA h g^–1) and MoS₂ (127.37 mA h g^–1) anodes.\nThe relevant kinetic mechanism was revealed by analyzing the pseudocapacitive\nsodium storage behavior and theoretical calculations. This work offers\nan effective strategy for developing a high-performance flexible SIB\nanode.