An aqueous copper battery enabled by Cu²⁺/Cu⁺ and Cu³⁺/Cu²⁺ redox conversion chemistry

Area of Science:

• Electrochemistry
• Materials Science
• Energy Storage

Background:

• Aqueous batteries offer a safer and more sustainable alternative to traditional batteries.
• Copper redox chemistry presents potential for high-capacity energy storage.
• Developing stable and efficient electrodes for aqueous copper systems is crucial.

Purpose of the Study:

• To investigate the feasibility of an aqueous copper battery using a novel redox conversion chemistry.
• To explore the performance of an activated carbon electrode in a copper chloride electrolyte.
• To enhance the discharge capacity and cycling stability of aqueous copper batteries.

Main Methods:

• Electrochemical characterization of an activated carbon electrode in a 30 m ChCl + 1 m CuCl2 electrolyte.
• Utilizing Cu2+/Cu+ and Cu3+/Cu2+ redox conversion chemistry.
• Cycling stability tests at approximately 1.0 V vs. Ag/AgCl.

Main Results:

• Demonstrated a functional aqueous copper battery based on Cu2+/Cu+ and Cu3+/Cu2+ redox couples.
• The Cu3+/Cu2+ redox couple significantly boosted discharge capacity by approximately 50 mA h g-1.
• Achieved stable cycling performance at around 1.0 V vs. Ag/AgCl.

Conclusions:

• The proposed aqueous copper battery system exhibits promising performance for energy storage applications.
• The Cu3+/Cu2+ redox chemistry is key to enhancing capacity in this system.
• Activated carbon electrodes are suitable for stable cycling in this copper-based aqueous electrolyte.