Reconstruction Effects of Layered Vanadium Oxides by Nanoengineering and Preintercalation for High Zinc-Ion Storage...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Layered vanadium oxides are promising cathode materials for aqueous zinc-ion batteries (AZIBs).
• Understanding the structure-property relationships of these materials is crucial for optimizing battery performance.
• Systematic comparisons are lacking to fully elucidate these relationships.

Purpose of the Study:

• To systematically investigate the effects of nanostructuring and preintercalation on the performance of layered vanadium oxide cathodes for AZIBs.
• To decouple the contributions of nanostructuring and preintercalation to energy storage properties.
• To provide insights into the structural engineering of advanced cathodes for AZIBs.

Main Methods:

• Fabrication of layered V2O5 nanobelts (single-layer α-V2O5 and bilayer hydrated δ-V2O5) with preintercalated cations (Mg2+, Ca2+, Ba2+) using a controllable synthesis protocol.
• Side-by-side comparison of energy storage performance and kinetics of synthesized samples.
• Analysis of the influence of cation species/content and structural water on electrochemical properties.

Main Results:

• Nanostructuring improved capacity and rate retention of α-V2O5 but did not resolve capacity decay.
• Preintercalation converted α-V2O5 to δ-V2O5, enhancing discharge capacity, rate retention, and cycling stability.
• Optimized Mg0.255V2O5·0.809H2O exhibited outstanding performance comparable to state-of-the-art vanadium oxide hydrate cathodes.

Conclusions:

• Preintercalation is a key strategy for enhancing the performance of layered vanadium oxide cathodes in AZIBs.
• The regulation of cations and structural water accelerates ion/electron transport and stabilizes the V2O5 framework.
• This work provides a fundamental understanding of reconstruction effects for designing superior cathodes for AZIBs and beyond.