Microstructural Insights Into LATP Ceramic Nanofibers for High-Performance Quasi-Solid-State Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Composite solid-state electrolytes (CPEs) are crucial for quasi-solid-state lithium metal batteries (QSLMBs), offering high ionic conductivity, electrochemical performance, and thermal stability.
• Conventional CPEs often struggle to significantly improve critical current density and rate performance due to limitations in ceramic particle dispersion within polymer matrices.
• Developing advanced ceramic nanofibers is essential for overcoming these limitations and enhancing QSLMB safety and efficiency.

Purpose of the Study:

• To present a green synthesis of NASICON-type Li_1.4Al_0.4Ti_1.6(PO₄)₃ ceramic nanofibers (LATP-NFs) using electrospinning.
• To optimize LATP-NF synthesis parameters for controlled microstructures.
• To evaluate the performance of a CPE incorporating LATP-NFs in QSLMBs.

Main Methods:

• Green synthesis of LATP-NFs via electrospinning, optimizing solvent type, precursor concentrations, heating rates, and calcination temperatures.
• Fabrication of a composite solid-state electrolyte by embedding 30 wt.% LATP-NF into a poly(vinylidene fluoride)-lithium bis(trifluoromethanesulfonyl)imide (PVDF-LiTFSI) matrix.
• Characterization of the CPE's ionic conductivity, thermal and electrochemical stability, mechanical strength, and lithium dendrite suppression capabilities.
• Assembly and testing of a LiFePO₄|LATP-30|Li battery cell to assess rate performance and cycling stability.

Main Results:

• The synthesized LATP-NFs were successfully embedded into a PVDF-LiTFSI matrix, forming a CPE with ionic conductivity of 0.21 mS cm^-1 at room temperature.
• The resulting CPE exhibited good thermal and electrochemical stability (>5 V) and enhanced mechanical strength.
• The LATP-30 CPE effectively suppressed lithium dendrite growth, achieving a high critical current density of 10 mA cm^-2.
• The LFP|LATP-30|Li cell demonstrated excellent rate capability (169 mAh g^-1 at 0.1 C, 101 mAh g^-1 at 10 C) and long-term cycling stability (97% capacity retention after 300 cycles at 0.5 C).

Conclusions:

• The green synthesis of LATP-NFs via electrospinning provides a sustainable and non-toxic strategy for producing advanced ceramic nanofibers.
• The developed LATP-30 CPE significantly enhances the critical current density and rate performance of QSLMBs by effectively suppressing lithium dendrite growth.
• This work demonstrates a promising approach for fabricating high-performance and safe quasi-solid-state lithium metal batteries.