Eutectic solvent as electrolytes for rechargeable proton batteries.

Area of Science:

• Materials Science
• Electrochemistry
• Chemical Engineering

Background:

• Proton batteries offer high energy density but face challenges with electrolyte stability and material dissolution.
• Titanium oxide (TiO_x) is a promising electrode material but tends to dissolve in conventional acidic aqueous electrolytes.

Purpose of the Study:

• To develop novel, stable, and nonflammable electrolytes for proton batteries.
• To investigate the efficacy of eutectic electrolytes in suppressing TiO_x dissolution.
• To evaluate the electrochemical performance of TiO_x-based proton batteries with the developed electrolytes.

Main Methods:

• Synthesis of eutectic electrolytes from trifluoromethanesulfonic acid hydrate (HTFSA) and methanesulfonic acid (MTFAA).
• Characterization of electrolyte properties, including stability and nonflammability.
• Electrochemical testing of TiO_x electrodes in the developed electrolytes, including cycling performance and capacity retention.

Main Results:

• Stable hydrogen-bonded liquid electrolytes were successfully formed from HTFSA and MTFAA.
• The developed eutectic electrolytes effectively suppressed the dissolution of TiO_x.
• A reversible capacity of 116 mA h g^-1 was achieved after 50 cycles, demonstrating good electrochemical stability.

Conclusions:

• Eutectic electrolytes based on HTFSA and MTFAA are promising nonflammable alternatives for proton batteries.
• These electrolytes enable stable cycling of TiO_x electrodes by preventing material dissolution.
• The developed system offers a pathway towards more robust and efficient proton battery technologies.