A Rechargeable Urea-Assisted Zn-Air Battery With High Energy Efficiency and Fast-Charging Enabled by Engineering...

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Electrochemical urea oxidation (UOR) is a promising alternative to oxygen evolution reaction (OER) for clean energy systems.
• Nickel-based catalysts show potential for UOR but suffer from self-oxidation, limiting their effectiveness.
• Developing strategies to enhance catalyst stability and activity is crucial for advancing UOR technology.

Purpose of the Study:

• To address the self-oxidation issue in nickel-based UOR catalysts.
• To improve UOR kinetics through interface chemistry modulation.
• To create a high-energy interfacial heterostructure for enhanced catalytic performance.

Main Methods:

• Designed a heterostructure catalyst (Ag-CoOOH@NiOOH) by incorporating silver (Ag) at the CoOOH@NiOOH interface.
• Investigated the interfacial interactions and electron exchange mechanisms.
• Evaluated the catalyst's performance in electrochemical urea oxidation and in rechargeable urea-assisted zinc-air batteries (ZABs).

Main Results:

• The Ag-CoOOH@NiOOH catalyst demonstrated ultrahigh UOR activity (1.33 V at 100 mA cm⁻²).
• Achieved a mass activity over 11.9 times greater than the initial cobalt oxyhydroxide.
• Urea-assisted ZABs exhibited record energy efficiency (74.56% at 1 mA cm⁻²), 1000-hour durability, and fast charging.

Conclusions:

• Interface chemistry modulation via Ag incorporation effectively boosts UOR kinetics and catalyst stability.
• The Ag-CoOOH@NiOOH catalyst represents a significant advancement for efficient electrochemical urea oxidation.
• This work paves the way for high-performance energy storage devices utilizing UOR.