Heterojunction tunnelled vanadium-based cathode materials for high-performance aqueous zinc ion batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Rechargeable aqueous zinc ion batteries (ZIBs) are a safe, cost-effective, and eco-friendly alternative to lithium-ion batteries.
• Current ZIB cathodes suffer from structural instability, low capacity, and slow reaction kinetics, hindering their practical application.

Purpose of the Study:

• To design and synthesize a BiVO4@VO2 heterojunction cathode material for enhanced ZIB performance.
• To investigate the electrochemical properties of the novel cathode in both aqueous and quasi-solid-state ZIBs.

Main Methods:

• Fabrication of a BiVO4@VO2 (BVO@VO) heterojunction cathode material.
• Electrochemical characterization of the BVO@VO cathode in aqueous and quasi-solid-state ZIBs, including capacity, cyclic stability, and rate performance tests.

Main Results:

• The BVO@VO cathode achieved a high capacity of 262 mAh g⁻¹ at 0.1 A g⁻¹.
• Demonstrated superb cyclic stability with 96% capacity retention after 1000 cycles at 2 A g⁻¹.
• Exhibited excellent rate capability, retaining 218 mAh g⁻¹ at 5.0 A g⁻¹.
• Flexible quasi-solid-state ZIBs showed a capacity of 234 mAh g⁻¹ over 100 cycles at 0.1 A g⁻¹.

Conclusions:

• The BiVO4@VO2 heterojunction effectively enhances zinc ion diffusion and electrochemical performance in ZIBs.
• This study presents a promising approach for developing high-performance vanadium-based cathodes for advanced zinc ion battery systems.