Developing High-Rate Aqueous Zinc-Ion Batteries with Zn-Doped V₁₀O₂₄·12H₂O Cathode

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Aqueous zinc-ion batteries (AZIBs) offer a safer, cost-effective alternative to lithium-ion batteries.
• Developing efficient cathode materials for reversible Zn2+ ion hosting remains a critical challenge for AZIBs.
• The electrochemical performance of V10O24.12H2O as an AZIB cathode and the impact of zinc doping were unexplored.

Purpose of the Study:

• To investigate the effect of zinc doping on the structural and electrochemical properties of V10O24.12H2O for AZIB cathode applications.
• To enhance the electronic conductivity and structural stability of the cathode material through zinc incorporation.

Main Methods:

• Hydrothermal synthesis of V10O24.12H2O and zinc-doped V10O24.12H2O (ZVO).
• Characterization of material morphology, zinc content (1.3%), and vanadium oxidation state (4.86).
• Density Functional Theory (DFT) calculations to assess the thermodynamic favorability and electronic conductivity enhancement of Zn doping.
• Electrochemical testing of Zn//ZVO and Zn//VO cells, including specific capacity, rate capability, and cycling stability.

Main Results:

• Zinc doping resulted in bundled rod-like ZVO morphology with improved electronic conductivity and structural stability.
• The Zn//ZVO cathode delivered a high specific capacity of 359 mAh/g at 0.1 A/g and maintained 121 mAh/g at 5 A/g.
• The Zn//ZVO cell demonstrated excellent cycle stability, retaining 90 mAh/g over 1110 cycles.

Conclusions:

• Zinc doping is a viable strategy to enhance V10O24.12H2O as a cathode material for AZIBs.
• The optimized ZVO cathode exhibits superior rate capability and long-term cycling performance compared to the pristine material.
• This work presents a promising cathode material for developing high-performance and stable aqueous zinc-ion batteries.