Intercalated CNT networks enable high-kinetic NH4V4O10 cathodes with long-term stability in aqueous zinc-ion batteries

Abstract

Aqueous zinc-ion batteries (AZIBs) represent a promising technology for large-scale energy storage due to their inherent safety, low cost, and environmental benefits. However, cathode dissolution and limited conductivity hinder their practical deployment. To address these challenges, this study successfully synthesized a composite cathode material consisting of NH₄V₄O₁₀ nanosheets integrated with carbon nanotubes (CNTs) – denoted as NH₄V₄O₁₀/CNTs – via a hydrothermal synthesis technique. Physical characterization revealed the uniform distribution of CNTs within the NH₄V₄O₁₀ interlayers, establishing a three-dimensional conductive framework that significantly enhances electron transport. Electrochemical evaluation demonstrated that the composite delivered a specific discharge capacity of 489.1 mAh g⁻¹ at 0.1 A g⁻¹. After subsequent cycling at higher rates and returning to 0.1 A g⁻¹, the capacity recovered to 435.3 mAh g⁻¹. The composite's rate capability substantially outperformed its pure-phase counterparts. Furthermore, at a high current density of 10 A g⁻¹, the composite maintained 85% of its capacity (157.5 mAh g⁻¹) after 4000 cycles. Kinetic analysis indicated a dominant pseudocapacitive contribution of 79.3% at a scan rate of 1.0 mV s⁻¹. These results collectively demonstrate that the NH₄V₄O₁₀/CNTs composite exhibits both rapid charge/discharge kinetics and long-term cycling stability, offering a viable approach for developing high-performance cathodes in AZIBs.