Rechargeable Mg-Br₂ Battery with Ultrafast Bromine Chemistry.

Area of Science:

• Materials Science
• Electrochemistry
• Sustainable Energy

Background:

• Diversified energy storage is crucial for a sustainable society.
• Magnesium metal batteries offer environmental friendliness, safety, and cost-effectiveness.
• High magnesium ion charge density hinders ion diffusion, limiting battery performance.

Purpose of the Study:

• To address sluggish magnesium ion diffusion in cathodes.
• To develop a high-power and high-energy-density magnesium metal battery.
• To propose a novel strategy inspired by the Hard-Soft-Acid-Base theory.

Main Methods:

• Implemented a soft-anion-induced bond weakening strategy using succinimide ion (SN⁻).
• Utilized SN⁻ in SN-Mg-Br to weaken the Mg-Br bond and promote magnesium ion transport.
• Developed a rechargeable Mg-Br₂ battery prototype.

Main Results:

• Achieved a high discharge plateau of 2.7 V and a specific capacity of 326 mAh gBr⁻¹.
• Demonstrated an impressive lifespan of 400 cycles with rapid magnesium ion transport.
• Enabled battery cycling at high rates (10 C) and ultralow temperatures (-55 °C).

Conclusions:

• The soft-anion-induced bond weakening strategy effectively overcomes magnesium ion diffusion challenges.
• This approach paves the way for high-performance magnesium-based battery systems.
• Advances sustainable energy storage solutions with enhanced power and energy density.