Minuscule ZnV2O4 Entrapped Carbon Nanofiber Composite Cathode for Long-Lasting Aqueous Zn-Ion Batteries

Abstract

Aqueous zinc-ion batteries (AZiBs) offer a sustainable, cost-effective, and safe alternative to lithium-ion batteries, yet they face challenges related to cathode limitations, such as low energy density and stability issues. In this study, we report the successful synthesis of minuscule ZnV2O4 nanoparticles uniformly integrated into conductive carbon nanofibers (m-ZnV2O4@CNFs) via electrospinning followed by a reduction heat treatment. Structural and electrochemical analyses demonstrate that this composite considerably improves ionic and electronic conductivity, reduces vanadium dissolution, and preserves structural integrity during extended cycling. In situ X-ray diffraction and Raman spectroscopy analyses reveal a partial structural transformation from the spinel ZnV2O4 phase to a layered vanadate phase, which stably coexists with residual spinel structures, enhancing both capacity and stability. Electrochemical testing demonstrates exceptional cycling stability, with a specific capacity of approximately 175 mAh<middle dot>g-1 after 600 cycles at 100 mA<middle dot>g-1, and outstanding longevity over 10,000 cycles at an increased current density of 2 A<middle dot>g-1. This study provides valuable insights into the design of multifunctional cathode materials, advancing the practical application of AZiBs.