Flame-Retardant Quasi-Solid-State Electrolytes From Self-Assembled Azolate Hybrid Frameworks for Highly Safe Lithium...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Quasi-solid-state electrolytes (QSSEs) are crucial for lithium batteries, but achieving both fast ion transport and thermal safety is challenging.
• Improving ionic conductivity often leads to increased flammability and interfacial instability in conventional electrolytes.

Purpose of the Study:

• To develop a novel QSSE that enhances ionic conductivity and thermal safety for lithium batteries.
• To create a general design principle for intrinsically safe, high-energy quasi-solid-state lithium batteries.

Main Methods:

• A spray-assisted in situ assembly strategy was used to construct azolate hybrid frameworks (AHFs) on glass fiber substrates.
• Thermal polymerization yielded a chemically integrated QSSE with ordered lithium-philic sites and continuous ion-transport pathways.
• Molecular confinement of triethyl phosphate (TEP) was employed for flame retardancy.

Main Results:

• The developed QSSE enabled efficient Li+ migration and maintained high thermal robustness.
• LiFePO4|FP10v-GF|Li cells showed stable cycling over 500 cycles at 25°C and 100 cycles at 60°C.
• High-loading Li||LiFePO4 cells demonstrated stable cycling under practical conditions and withstood temperatures up to 300°C without thermal runaway.

Conclusions:

• Framework chemistry and molecular confinement can be synergistically integrated to decouple ionic conductivity from flammability.
• This approach provides a viable pathway for intrinsically safe, high-energy quasi-solid-state lithium batteries.
• The novel QSSE design offers a promising solution for advanced energy storage applications.