Dual Interface Compatibility Enabled via Composite Solid Electrolyte with High Transference Number for Long-Life...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Solid-state electrolytes (SSEs) offer a safer alternative to liquid electrolytes in lithium metal batteries by mitigating dendrite growth and flammability issues.
• All-solid-state lithium metal batteries (ASSLMBs) are a promising next-generation energy storage technology due to their potential for high energy density and improved safety.
• Developing SSEs with high ionic conductivity, stability, and excellent interface compatibility remains a critical challenge.

Purpose of the Study:

• To design and synthesize a novel composite solid electrolyte for ASSLMBs.
• To investigate the synergistic effects of inorganic and organic components on the electrolyte's properties.
• To evaluate the electrochemical performance and cycling stability of batteries utilizing the developed composite solid electrolyte.

Main Methods:

• Fabrication of a composite solid electrolyte using Li6.25Al0.25La3Zr2O12 (LLZO), Al2O3, and polyvinylidene difluoride (PVDF).
• Characterization using X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) calculations.
• Electrochemical testing of Li||Li symmetric batteries and ASSLMBs with LiNi0.6Co0.2Mn0.2O2 cathodes and all-solid-state lithium-sulfur batteries.

Main Results:

• The composite solid electrolyte exhibited enhanced ionic conductivity, a high lithium-ion transference number, and an extended electrochemical window due to synergistic effects.
• Li||Li symmetric batteries demonstrated stable cycling for over 2500 hours.
• ASSLMBs with a LiNi0.6Co0.2Mn0.2O2 cathode achieved a discharge capacity of 168 mAh g-1 after 360 cycles, and all-solid-state lithium-sulfur batteries showed an initial capacity of 912 mAh g-1.

Conclusions:

• The rationally designed composite solid electrolyte offers a promising solution for next-generation high-energy-density ASSLMBs.
• The synergistic interaction between LLZO, Al2O3, and PVDF significantly improves ionic conductivity and interface stability.
• The developed electrolyte enables long-life and high-performance ASSLMBs, paving the way for safer and more efficient energy storage solutions.