Rapid Self-Healing Gel Electrolyte Based on Deep Eutectic Solvents for Solid-State Lithium Batteries.

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Deep eutectic solvents (DES) are promising electrolytes for lithium metal batteries.
• Liquid DES electrolytes present safety concerns and side reactions with lithium anodes.
• Solidification of DES electrolytes is crucial for enhanced electrochemical stability.

Purpose of the Study:

• To develop a novel DES-based gel electrolyte with rapid self-healing properties.
• To improve the safety and electrochemical stability of lithium metal batteries.
• To investigate the performance of solid-state lithium batteries utilizing the developed gel electrolyte.

Main Methods:

• Synthesis of a novel DES-based gel electrolyte with rapid self-healing capabilities.
• Characterization of the electrolyte's self-healing time (30 min).
• Evaluation of noncombustibility (4 s g^-1), ionic conductivity (1.1 × 10^-3 S cm^-1), and electrochemical voltage window (4.5 V vs Li/Li⁺).
• Fabrication and testing of solid-state lithium batteries with LiFePO₄ cathodes.

Main Results:

• The gel electrolyte demonstrates rapid self-healing of surface cracks within 30 minutes.
• The electrolyte exhibits excellent noncombustibility, high ionic conductivity, and a wide electrochemical voltage window.
• Solid-state batteries achieved a high specific capacity of 135.4 mA h g^-1.
• Durable cyclic stability exceeding 1200 hours was observed.

Conclusions:

• The developed DES-based gel electrolyte offers a safe and high-performance alternative for solid-state lithium batteries.
• Rapid self-healing and noncombustibility address key safety concerns associated with liquid DES electrolytes.
• The findings provide valuable insights for designing advanced fire-resistant, high-energy solid-state lithium batteries.