A Supramolecular Deep Eutectic Electrolyte Enhancing Interfacial Stability and Solution Phase Discharge in Li-O₂...

Area of Science:

• Electrochemistry
• Materials Science
• Energy Storage

Background:

• Lithium-oxygen batteries (LOBs) offer high energy density but are limited by electrolyte challenges.
• Effective electrolytes require balanced reactant transport, interfacial compatibility, and non-volatility.

Purpose of the Study:

• To develop a novel electrolyte for lithium-oxygen batteries that overcomes existing limitations.
• To enhance redox stability, facilitate solution-phase discharge, and improve lithium anode compatibility.

Main Methods:

• A supramolecular deep eutectic electrolyte (DEE) was synthesized using lithium salt (LiTFSI), acetamide (Ace), and boric acid (BA).
• Boric acid was incorporated as an interface modification additive, acting as Li-bond acceptor and H-bond donor/acceptor.
• Electrochemical performance was evaluated in Li-O2 batteries, including oxidation voltage, discharge capacity, and cycling stability.

Main Results:

• The developed DEE exhibited a high oxidation voltage of 4.5 V.
• An ultrahigh discharge capacity of 15225 mAh g⁻¹ was achieved.
• Stable cycling performance of 196 cycles was demonstrated, along with intrinsic non-flammability.

Conclusions:

• The novel DEE effectively addresses key challenges in lithium-oxygen battery electrolytes.
• The electrolyte shows promising practical applications due to its performance and safety features.
• This research expands design strategies for LOB electrolytes and offers theoretical insights.