Constructing an Electron-Ion Dual-Conductive Network via MXene Shell for Stable Aluminum Powder Anodes in Aqueous...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Rechargeable aqueous aluminum-ion batteries (AAIBs) are promising for grid-scale energy storage.
• A key challenge is the lack of stable anodes, particularly when using high-capacity aluminum powder (Al-p).

Purpose of the Study:

• To develop a stable and high-performance anode for AAIBs.
• To address the limitations of aluminum powder anodes through structural modification.

Main Methods:

• Fabrication of a core-shell MXene@Al composite anode by encapsulating Al-p with Ti₃C₂T_x MXene via mechanical ball milling.
• Integration into a self-supporting electrode on a zinc foam substrate.
• Electrochemical testing of symmetric and full cells, theoretical simulations, and finite element analysis.

Main Results:

• The MXene@Al symmetric battery achieved a 600 h cycle life with low overpotential (<40 mV at 0.1 mA cm^-2).
• The MXene@Al∥Cu half-cell showed 98.93% Coulombic efficiency after 300 cycles.
• A full cell with MnO₂ maintained 97.6% capacity retention after 250 cycles at 0.2 A g^-1.
• Theoretical and finite element analyses confirmed enhanced interface stability and suppressed dendrite formation.

Conclusions:

• The MXene@Al composite anode effectively prevents Al-p aggregation and creates a dual-electron-ion conductive network.
• This core-shell structure significantly improves the electrochemical performance and stability of AAIBs.
• The study presents a scalable strategy for developing practical, high-performance AAIBs.