Self-Sacrificing Interface Engineering for Enhanced Compatibility and Ionic Conduction in LLZTO/Polymer-Based...

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• PVDF-based electrolytes face challenges in solid-state lithium batteries due to interfacial instability and low ionic conductivity.
• Developing stable interfaces is crucial for advancing solid-state battery technology.

Purpose of the Study:

• To propose a molecular self-sacrificing strategy using bis(catecholato)diboron (B2cat2) to stabilize the LLZTO/P(VDF-CTFE) interface.
• To enhance the bulk and interfacial stability of PVDF-based electrolytes for solid-state lithium batteries.

Main Methods:

• Utilized bis(catecholato)diboron (B2cat2) as a molecular additive.
• Employed spectroscopic analyses including UV-vis, XPS, and NMR to confirm interactions.
• Fabricated optimized eutectogel hybrid electrolytes (EHEs).

Main Results:

• B2cat2 effectively suppressed dehydrofluorination and regulated residual DMF, improving electrolyte stability.
• Spectroscopic data confirmed strong interactions between B2cat2 and LLZTO, enhancing ion transport.
• Achieved high lithium conductivity (0.59 mS cm-1), a high lithium-ion transference number (0.66), and long-term cycling stability (1000 h).
• Demonstrated excellent full-cell performance with LiFePO4 and NCM811 cathodes and remarkable pouch cell stability across a wide temperature range.

Conclusions:

• The molecular self-sacrificing strategy using B2cat2 successfully stabilized the LLZTO/P(VDF-CTFE) interface.
• The developed EHEs exhibit promising properties for high-performance and stable solid-state lithium batteries.
• This approach offers a viable route for constructing robust interfaces in next-generation energy storage devices.