Electrostatic Shielding Guides Lateral Deposition for Stable Interphase toward Reversible Magnesium Metal Anodes

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Magnesium (Mg) anodes offer high theoretical capacity but face challenges with dendritic deposition and passivation.
• Intrinsic surface roughness and non-uniform solid-electrolyte interphase (SEI) formation lead to uneven Mg deposition and high local current densities.
• Poor interfacial stability and potential penalties limit the practical application of Mg metal anodes.

Purpose of the Study:

• To address the challenges of uneven Mg deposition and interfacial instability in Mg metal anodes.
• To develop a strategy for guiding smooth Mg deposition and enhancing SEI stability.
• To improve the electrochemical reversibility and overall performance of Mg metal batteries.

Main Methods:

• Electrolyte modification using cathodically stable cations.
• Implementation of an electrostatic shielding strategy to guide Mg deposition.
• Investigation of Mg deposition uniformity and SEI characteristics.

Main Results:

• Cathodically stable cations effectively homogenize charge flux by repelling Mg²⁺ from surface protuberances.
• The electrostatic shielding strategy promotes smooth Mg deposition, mitigating uneven growth.
• Enhanced lateral growth of Mg contributes to improved SEI stability and electrochemical reversibility.

Conclusions:

• Electrolyte modification with specific cations is a viable strategy for achieving uniform Mg deposition.
• The electrostatic shielding mechanism effectively controls Mg deposition morphology and enhances interfacial stability.
• This approach offers a promising pathway for developing high-performance and stable magnesium metal batteries.