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 ZnV<inf>2</inf>O<inf>4</inf> nanoparticles uniformly integrated into conductive carbon nanofibers (m-ZnV<inf>2</inf>O<inf>4</inf>@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 ZnV<inf>2</inf>O<inf>4</inf> 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·g−1 after 600 cycles at 100 mA·g−1, and outstanding longevity over 10,000 cycles at an increased current density of 2 A·g−1. This study provides valuable insights into the design of multifunctional cathode materials, advancing the practical application of AZiBs. © 2025 Elsevier B.V., All rights reserved.