Highly Stable Aqueous Zinc-Ion Storage Using a Layered Calcium Vanadium Oxide Bronze Cathode

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Aqueous rechargeable batteries offer cost-effective, safe alternatives to non-aqueous systems for grid storage.
• Zinc-ion batteries (ZIBs) are promising due to high-capacity zinc metal anodes and Zn²⁺ intercalation chemistry.

Purpose of the Study:

• To introduce a layered calcium vanadium oxide bronze as a novel cathode material for aqueous ZIBs.
• To evaluate the electrochemical performance, storage mechanism, and kinetics of the proposed cathode.

Main Methods:

• Synthesis and characterization of the layered calcium vanadium oxide bronze cathode.
• Electrochemical testing of zinc-ion cells, including capacity, rate capability, and cycling stability measurements.
• Investigation of the Zn²⁺ ion storage mechanism and electrochemical kinetics.

Main Results:

• The calcium vanadium oxide bronze cathode delivered a high capacity of 340 mA h g^-1 at 0.2 C.
• The material exhibited excellent cycling life, retaining 96% capacity after 3000 cycles at 80 °C.
• The zinc-ion cell achieved an energy density of 267 Wh kg^-1 at a power density of 53.4 W kg^-1.

Conclusions:

• The developed layered calcium vanadium oxide bronze is a highly promising cathode material for cost-effective and high-performance aqueous zinc-ion batteries.
• The study provides insights into the Zn²⁺ storage mechanism and electrochemical kinetics, paving the way for further optimization.
• This material demonstrates significant potential for stationary grid energy storage applications.