Vanadium Oxide/MXene Composite Fiber Cathodes With Superior Spinnability Enabling High Electrochemical Performance for Fiber-Shaped Zinc-Ion Batteries.

Abstract

Fiber-shaped zinc-ion batteries are highly deformable and can store energy in irregular spaces. Fiber cathodes with carbon fiber cores can be continuously prepared via wet spinning. In this work, MXene is introduced into the cathode by directly hybridizing with vanadium oxide, acting as a bridge to enhance the interfacial interaction within the cathode. MXene modifies the rheological behavior of the cathode slurry and facilitates the rearrangement of the active material during wet spinning, thereby effectively improving fiber spinnability and mitigating agglomeration of the active material. Additionally, MXene enhances the electrical conductivity of the active material and stabilizes the structure of VO2, enabling the composite cathode to deliver satisfactory specific capacity and cycling stability. The cathode achieves a specific capacity of 136 mAh g-1 at 3 A g-1 after 2000 cycles, which is 109% higher than that of the pure VO2 cathode. The cathodes are assembled with MXene/chitosan-coated fiber anodes and a hydrogel electrolyte to make full batteries. The resulting battery packs can power lighting and communication modules in small unmanned aerial vehicles. This work leverages the multiple advantages of MXene in various dimensions, proposes an optimization strategy for carbon-fiber-based fiber-shaped batteries, and highlights their application potential.