Dimethyl sulfoxide as a function additive on halogen-free electrolyte for magnesium battery application

Area of Science:

• Electrochemistry
• Materials Science
• Energy Storage

Background:

• Practical magnesium (Mg) batteries face challenges including incompatible electrolytes, self-discharge, Mg anode passivation, and slow reaction kinetics.
• Developing stable and efficient electrolytes is crucial for advancing Mg battery technology.
• Current electrolytes often struggle with Mg anode stability and ion transport.

Purpose of the Study:

• To develop a simple, halogen-free electrolyte (HFE) for magnesium batteries.
• To investigate the effect of dimethyl sulfoxide (DMSO) as an additive on electrolyte properties and Mg anode behavior.
• To enhance the performance and stability of Mg batteries.

Main Methods:

• Formulation of a new halogen-free electrolyte (HFE) using magnesium nitrate, magnesium triflate, succinonitrile, and acetonitrile/tetraethylene glycol dimethyl ether cosolvents.
• Inclusion of dimethyl sulfoxide (DMSO) as a functional additive.
• Electrochemical characterization including conductivity, ionic transference number, oxidation stability, and Mg stripping/plating tests; postmortem analysis of Mg anodes.

Main Results:

• The HFE with 0.75 ml DMSO exhibited high ionic conductivity (up to 9.41 × 10^-5 S cm^-1) and a high Mg ion transference number (0.91/0.94).
• The electrolyte demonstrated high oxidation stability, low overpotential, and stable Mg stripping/plating for 100 hours.
• DMSO addition modified the Mg anode/electrolyte interface, facilitating Mg ion transport and improving anode surface characteristics.

Conclusions:

• The developed halogen-free electrolyte with DMSO additive significantly improves Mg anode interfacial properties and ion transport.
• This electrolyte formulation shows promising potential for high-performance and stable magnesium battery applications.
• Further optimization is expected to yield excellent cycle stability for future magnesium battery development.