Intercalation-induced amorphous hydrated vanadium oxide for boosted aqueous Zn²⁺ storage

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Vanadium pentoxide (V2O5·nH2O) is a promising cathode material for zinc-ion batteries (ZIBs).
• However, V2O5-based cathodes suffer from dissolution issues, limiting their long-term stability and performance.
• Intercalation of other ions can modify the structure and properties of V2O5.

Purpose of the Study:

• To develop a high-performance cathode material for ZIBs by inducing Zn2+ intercalation in Mg-ion inserted V2O5·nH2O.
• To investigate the structural evolution and electrochemical properties of the modified vanadium oxide.
• To address the vanadium dissolution issue and enhance the cycling stability of ZIBs.

Main Methods:

• Synthesis of amorphous hydrated vanadium oxide via Zn2+ intercalation in Mg-ion inserted V2O5·nH2O.
• Electrochemical characterization including galvanostatic cycling, cyclic voltammetry, and electrochemical impedance spectroscopy.
• Ex-situ characterization techniques to analyze the phase transitions and structural changes during cycling.

Main Results:

• The developed Mg-ion inserted V2O5·nH2O (MgVOH) material, after Zn2+ intercalation, forms an amorphous hydrated vanadium oxide.
• This new cathode exhibits high performance in ZIBs.
• The formation of zinc pyrovanadate during the second phase transition effectively suppresses vanadium dissolution, leading to an extended lifespan.

Conclusions:

• Amorphous hydrated vanadium oxide induced by Zn2+ intercalation in MgVOH is a high-performance cathode for ZIBs.
• The formation of zinc pyrovanadate is crucial for mitigating vanadium dissolution and achieving long cycle life.
• This work offers a promising strategy for developing stable and efficient cathode materials for next-generation energy storage devices.