An aqueous Al-PbO₂ battery with pH-gradient engineering surpasses 3.5 V

Area of Science:

• Electrochemistry
• Materials Science
• Energy Storage

Background:

• Aqueous batteries offer safer alternatives to organic electrolytes but are limited by water's electrochemical stability window.
• Developing high-voltage aqueous batteries is crucial for advancing electrochemical energy storage technologies.
• Aluminum-based batteries are promising due to aluminum's abundance and high volumetric capacity.

Purpose of the Study:

• To design and investigate a novel aqueous Al-PbO2 hybrid battery system.
• To overcome the electrochemical stability limitations of aqueous electrolytes.
• To achieve high voltage and energy density in an aqueous battery platform.

Main Methods:

• Fabrication of an aqueous Al-PbO2 hybrid battery.
• Implementation of a pH-gradient design to enhance electrochemical stability.
• Utilizing a decoupled charging process for energy-efficient operation and hydrogen generation.

Main Results:

• The Al-PbO2 hybrid battery achieved a high operating voltage of 3.52 V.
• Demonstrated high power density (914 mW cm-2) and capacity (11.85 mAh cm-2).
• The pH-gradient design successfully surpassed the electrochemical stability limit of water.

Conclusions:

• The developed aqueous Al-PbO2 hybrid battery represents a significant advancement in high-voltage aqueous energy storage.
• The pH-gradient design is an effective strategy for enhancing the stability and performance of aqueous batteries.
• This platform offers a multifunctional approach for energy storage with potential for hydrogen generation.