Regenerable Cu-intercalated MnO₂ layered cathode for highly cyclable energy dense batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Manganese dioxide cathodes offer high theoretical capacity but limited accessibility in rechargeable systems.
• Current rechargeable alkaline systems utilize only ~10% of theoretical capacity.
• Previous attempts to enhance capacity using additives have been unsuccessful.

Purpose of the Study:

• To develop a rechargeable cathode material with near-full theoretical capacity.
• To investigate the role of copper intercalation in Bi-birnessite for enhanced electrochemical performance.
• To demonstrate a high-energy-density rechargeable battery system.

Main Methods:

• Synthesis of Bi-birnessite layered structures intercalated with Cu2+.
• Electrochemical cycling of modified cathodes in rechargeable alkaline systems.
• Characterization of structural and charge transfer properties during cycling.

Main Results:

• Bi-birnessite cathodes intercalated with Cu2+ achieved reversible near-full two-electron capacity.
• Stable cycling performance exceeding 6,000 cycles was demonstrated.
• A large prismatic rechargeable Zn-birnessite cell achieved ~140 Wh/l energy density.

Conclusions:

• Exploiting copper redox potentials enables reversible intercalation and stabilization of Bi-birnessite structure.
• This approach significantly enhances charge transfer and rechargeability.
• The findings hold potential for catalysis and metal ion intercalation applications.