Activating Selenium Cathode Chemistry for Aqueous Zinc-Ion Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Aqueous rechargeable zinc-ion batteries (ARZIBs) offer safety and cost benefits but lack high volumetric capacity cathodes.
• Developing compact and lightweight ARZIBs requires advanced cathode materials.

Purpose of the Study:

• To develop a novel cathode material for ARZIBs with enhanced volumetric capacity and stability.
• To mitigate performance limitations caused by side reactions in selenium-based cathodes.

Main Methods:

• Synthesized amorphous selenium doped with transition metal ruthenium (Ru) as a cathode material.
• Investigated the electrochemical performance of Ru-doped amorphous Se||Zn half cells.
• Analyzed the intercalation/deintercalation mechanisms and surface layer mitigation.

Main Results:

• Achieved a record-high capacity of 721 mAh g⁻¹ /3472 mAh cm⁻³ in Ru-doped amorphous Se||Zn half cells.
• Demonstrated superior cycling stability with over 800 cycles and minimal capacity decay (0.015% per cycle).
• Observed synchronous proton and Zn²⁺ intercalation/deintercalation and an effective Zn²⁺ deposition/stripping process.

Conclusions:

• Ruthenium-doped amorphous selenium presents a promising cathode chemistry for high-performance ARZIBs.
• This work enables lighter and more compact ARZIBs by improving gravimetric and volumetric capacity.
• The findings open avenues for new cathode chemistries in next-generation energy storage.