Engineering and regulating the interfacial stability between Li_1.3Al_0.3Ti_1.7(PO₄)₃-based solid electrolytes and...

Area of Science:

• Materials Science
• Electrochemistry
• Solid-State Batteries

Background:

• Solid-state electrolytes like Li₁․₃Al₀․₃Ti₁․₇(PO₄)₃-F (LATP-F) are promising for safer lithium batteries.
• Interfacial instability between solid electrolytes and lithium metal anodes remains a major challenge.
• Dendrite growth and side reactions degrade battery performance and lifespan.

Purpose of the Study:

• To design and fabricate InCl₃-coated LATP-F solid electrolyte powders.
• To investigate the effect of the InCl₃ coating on the interfacial properties and electrochemical performance of LATP-F based lithium batteries.
• To elucidate the mechanisms behind the improved interfacial stability and lithium dendrite suppression.

Main Methods:

• Wet-chemical coating of InCl₃ onto F⁻-doped LATP powders.
• Fabrication of Li/InCl₃@LATP-F/Li symmetric cells and LiCoO₂/InCl₃@LATP-F/Li full cells.
• Electrochemical testing including cycling stability, interfacial resistance measurements, and rate capability tests.
• Analysis of interfacial reactions and lithium dendrite formation.

Main Results:

• The Li/InCl₃@LATP-F/Li cell demonstrated significantly longer cycling stability (2500 h vs 1837 h) compared to the uncoated LATP-F cell.
• Interfacial resistance sharply decreased from 3428 Ω to 436 Ω in the first 500 h for the InCl₃-coated cell.
• The LiCoO₂/InCl₃@LATP-F/Li cell achieved a high discharge specific capacity of 126.4 mAh g⁻¹ with 95.42% retention after 100 cycles.
• The InCl₃ layer formed a lithiophilic Li-In alloy, promoting homogeneous ion flux and suppressing lithium dendrites.
• The coating prevented direct contact between LATP-F and Li metal, mitigating Ti⁴⁺ reduction and preserving structural integrity.

Conclusions:

• The InCl₃ coating is an effective strategy to enhance the interfacial stability between LATP solid electrolytes and lithium metal anodes.
• The formation of a Li-In alloy at the interface is crucial for homogeneous lithium ion transport and dendrite suppression.
• This approach offers a promising pathway for developing high-performance and long-lasting LATP-type solid-state lithium batteries.