Aqueous Rechargeable Magnesium Battery with a High Output Voltage Using a Hydrated Eutectic Electrolyte

Area of Science:

• Electrochemistry
• Materials Science
• Energy Storage

Background:

• Rechargeable magnesium batteries are promising for safe and cost-effective energy storage.
• Key challenges include narrow electrochemical stability windows, interfacial instability, and slow Mg2+ transport.

Purpose of the Study:

• To address the limitations of current magnesium battery electrolytes.
• To enhance the stability and electrochemical performance of magnesium batteries through electrolyte engineering.

Main Methods:

• Designed a multi-component hydrated eutectic electrolyte (DM11) using Mg(ClO4)2, acetamide, caprolactam, and H2O.
• Investigated electrolyte properties including electrochemical stability window and interfacial behavior.
• Tested symmetric Mg//Mg cells and Mg//Mg-MnO2 full batteries.

Main Results:

• The DM11 electrolyte broadened the electrochemical stability window to 4 V.
• An organic-inorganic hybrid layer formed on the Mg surface, reducing corrosion.
• Stable cycling was achieved for over 500 h in Mg//Mg cells.
• Mg//Mg-MnO2 full batteries showed a reversible capacity of 300 mA h g-1 and stable cycling for over 500 cycles at 0.5 A g-1.

Conclusions:

• The engineered hydrated eutectic electrolyte (DM11) effectively enhances magnesium battery performance.
• This strategy offers a viable route for developing stable and high-performance magnesium batteries.