Dual-layer hybrid solid electrolyte for improved interfacial stability in solid-state lithium batteries.

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Hybrid solid electrolytes (HSEs) combine polymer and ceramic advantages for solid-state lithium batteries (SSLBs).
• Single-layer electrolytes face performance degradation due to interfacial incompatibility with electrodes.
• Addressing interfacial challenges is crucial for advancing high-performance SSLBs.

Purpose of the Study:

• To design and investigate a dual-layer structured electrolyte for SSLBs.
• To enhance electrochemical performance by optimizing interfacial compatibility with both cathode and anode.
• To improve ionic conductivity, mechanical properties, and cycling stability.

Main Methods:

• Synthesized a dual-layer hybrid solid electrolyte using Zr-doped Li₁.₃Al₀.₃Ti₁.₇(PO₄)₃ (LAZTP).
• Characterized ionic conductivity, mechanical properties (tensile strength, Young's modulus), and Li plating/stripping stability.
• Fabricated and tested LiFePO₄ (LFP)/LAZTP dual HSE/Li SSLBs.

Main Results:

• The LAZTP dual HSE achieved high ionic conductivity (5.0 × 10⁻⁴ S cm⁻¹).
• Improved mechanical properties were observed (tensile strength 6.32 MPa, Young's modulus 30.9 MPa).
• Demonstrated stable Li plating/stripping for 500 hours and excellent battery performance (155.7 mAh g⁻¹ at 0.5C, 92.6% retention over 200 cycles).

Conclusions:

• The dual-layer electrolyte design effectively addresses interfacial incompatibility in SSLBs.
• The developed LAZTP dual HSE offers superior ionic conductivity, mechanical strength, and electrochemical stability.
• This work presents a promising strategy for developing next-generation high-performance solid-state lithium batteries.