Constructing Stable and Efficient Solid Electrolytes Based on Zirconium-Doping on Li₄Ti₅O₁₂ for Solid-State Lithium...

Area of Science:

• Materials Science
• Electrochemistry
• Solid-State Batteries

Background:

• Solid-state lithium metal batteries (SSLMBs) are crucial for next-generation energy storage.
• Developing solid-state electrolytes with high ionic conductivity and low electronic conductivity is a key challenge.

Purpose of the Study:

• To develop a composite solid electrolyte (CSE) for SSLMBs.
• To enhance ionic conductivity and suppress electronic conductivity for improved battery performance.

Main Methods:

• Fabrication of a composite solid electrolyte (CSE) using doped Li4Ti4.95Zr0.05O12 (LTZO1) and poly(vinylidene fluoride) (PVDF).
• Density functional theory (DFT) calculations to investigate the effect of Zr doping on Li+ transport.
• Electrochemical characterization of the CSE, including ionic conductivity, electronic conductivity, and critical current density.

Main Results:

• Zr doping in LTZO1 reduced the energy barrier for Li+ transport, increasing ionic conductivity from 0.228 to 0.665 mS cm-1.
• Electronic conductivity was significantly suppressed from 0.11 mS cm-1 to 2.4 × 10-6 S cm-1.
• The optimized CSE demonstrated enhanced ionic conductivity (0.171 to 0.581 mS cm-1), low electronic conductivity, and a critical current density of 5.5 mA cm-2.

Conclusions:

• The developed CSE exhibits excellent properties for SSLMBs.
• The composite material enables rapid ion conduction and electron blocking, crucial for battery safety and performance.
• This work presents a viable strategy for creating practical CSEs for advanced solid-state batteries.