Integrating amorphous vanadium oxide into carbon nanofibers via electrospinning as high-performance anodes for alkaline ion (Li⁺/Na⁺/K⁺) batteries

To explore advanced anode materials with superior Li⁺/Na⁺/K⁺ storage performances for alkaline ion batteries (AIBs), a hybrid of amorphous vanadium oxide uniformly embedded into the highly defective carbon nanofibers (denoted as VO_x@CNFs) was fabricated via a facile electrospinning method followed by proper heat treatment in this work. The integrated structure synergistically combines the advantages of the amorphous VO_x and the defective carbon matrices, which can not only bring abundant active sites for ion storage and multi-channels for ion diffusion, but also well accommodate the structural change induced electrode pulverization. When evaluated as anode materials for AIBs, the optimized VO_x@CNFs demonstrate excellent alkaline ion storage performances with high-specific capacities, long-cycling life and high-rate capabilities, delivering a Na⁺ storage capacity of 260 mAh g⁻¹ at 1.0 A g⁻¹ after 1000 cycles, a Li⁺ storage capacity of 556 mAh g⁻¹ at 0.5 A g⁻¹after 500 cycles, and a K⁺ storage capacity of 198 mAh g⁻¹ at 0.5 A g⁻¹ after 400 cycles.