Bilayered V2O5 Nanostrands with PVA-Based Cathode Slurry for High-Performance and Sustainable Zinc-Ion Batteries

Abstract

Increasing demand for sustainable and cost-effective batteries has accelerated in-depth research on zinc ion batteries (ZIBs) as an ideal alternative for lithium-ion batteries (LIBs). V2O5 is a widely investigated material for charge storage due to its rich electrochemistry, however the bulky crystalline structure in commercial V2O5 hinders its high potential by constraining Zn2+ ion migration, structural instability and premature failure. In this study we present a low-cost, scalable and eco-friendly strategy to synthesize layered V2O5 in a one-pot process with polyvinyl alcohol (PVA) as a binder producing a ready to coat cathode slurry. Furthermore, we have eliminated the usage of fluorinated plastics such as polyvinylidene fluoride (PVDF) and solvents like N-methyl pyrrolidone (NMP) which are traditionally employed for cathode slurry preparation, which are non-biodegradable and toxic. The proposed method results in a material's interlayer spacing of 8.4 Å which significantly improves the Zn 2+ ion migration.And PVA assisted binding improves the electrolyte -active material interphase, resulting in efficient charge transfer. Electrochemical characterization showcases remarkable cyclability of proposed cathode material with a 480 mAh g-1 at 0.5 A g-1 for 100 cycles and an exceptional long-term cyclability of 280 mAh g-1 at 4 A g-1 over 6500 cycles, retaining 98% capacity in the last 6000 cycles. Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic intermittent titration technique (GITT) further confirm highly efficient and favourable charge transfer kinetics with promising fast charging properties. This study highlights the potential of bilayered V2O5 nanostrands and green processing approaches for scalable and sustainable ZIB production, paving the way for next-generation grid-scale energy storage.