Hierarchically stacked nanocrystalline VS2 nanoflowers for enhanced zinc-ion storage performance

Abstract

Aqueous zinc-ion batteries (AZIBs) have garnered significant attention due to their low cost, high safety performance, and environmental friendliness. In this work, a polycrystalline VS₂ nanoflower with a stacked lamellar structure (P-VS₂) was synthesized via a facile one-step hydrothermal method. The unique polycrystalline architecture features expanded and abundant ion diffusion pathways, which enhance Zn²⁺ storage kinetics and structural stability. When evaluated as a cathode for AZIBs, the P-VS₂ electrode delivers a high specific capacity of 222 mA h g⁻¹ at 0.1 A g⁻¹ and retains 150 mA h g⁻¹ at 2 A g⁻¹, outperforming its monocrystalline VS₂ counterpart (M-VS₂). Notably, the P-VS₂ cathode exhibits exceptional cycling stability with 90.3% capacity retention after 1000 cycles at 2 A g⁻¹. Mechanism studies reveal that the polycrystalline framework mitigates structural strain during repeated Zn²⁺ intercalation/deintercalation, while the multivalent redox reactions of vanadium contribute to enhanced charge storage. This work provides a rational design strategy for high-performance cathode materials in advanced AZIBs.