Molecular-Locking Strategy Enables Volatile Ether Organic Electrolytes to Achieve High-Energy Lithium Battery

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• High-energy lithium metal batteries require stable electrolytes to overcome safety and lifespan limitations.
• Current electrolytes often struggle with nonpolar solvents, leading to safety hazards and performance degradation.

Purpose of the Study:

• To develop a novel gel electrolyte for high-energy lithium metal batteries using polyoxometalate subnanometer nanowires.
• To enhance the safety, stability, and performance of lithium metal batteries by enabling the use of ether-based electrolytes.

Main Methods:

• A gel electrolyte was synthesized using cations-bridged polyoxometalate subnanometer nanowires (SNW) for molecular locking and gelation.
• The SNW-based gel electrolyte (SNWGE) was characterized for its structural, electrochemical, and interfacial properties.
• Performance was evaluated in lithium-metal cells (Li||NMC811) and lithium-air batteries.

Main Results:

• The SNWGE effectively immobilizes nonpolar ether electrolytes, preventing leakage and volatilization while promoting Li salt dissociation.
• It provides continuous Li+ transport channels, achieving high ionic conductivity (1.26 mS cm⁻¹), excellent oxidative stability (5.0 V), and robust interphase formation.
• Cells demonstrated superior cyclability (>88% retention after 670 cycles), low-temperature performance, and abuse tolerance.
• SNWGE exhibits a significantly lower cost (28.5% of commercial electrolyte) and enables stable cycling (>520 cycles) in Li-air batteries.

Conclusions:

• The SNWGE design offers a promising strategy for creating highly energetic, durable, and safe rechargeable lithium metal batteries.
• This cost-effective electrolyte solution has significant potential for industrial applications in next-generation energy storage.