Highly Conductive and Supertough PVDF-Based Electrolytes with Self-Defective Fillers for Solid-State Lithium Metal...

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Solid-state lithium-metal batteries (SSLMBs) require advanced electrolytes with high ionic conductivity, mechanical robustness, and electrochemical stability.
• Achieving these properties simultaneously in traditional PVDF-based electrolytes remains a significant challenge for practical applications.

Purpose of the Study:

• To develop highly conductive and mechanically robust PVDF-based electrolytes for SSLMBs.
• To investigate the role of self-defective silicon fillers in enhancing electrolyte performance.

Main Methods:

• Doping PVDF matrix with self-defective silicon (Si) fillers featuring Si/SiO_x heterogeneous interfaces.
• Characterizing the ionic conductivity, mechanical properties, and electrochemical stability of the modified electrolytes.
• Evaluating battery performance using Li||Li symmetrical and LFP||Li cells.

Main Results:

• The modified electrolytes exhibit an ionic conductivity of 0.44 mS cm^-1, tensile strength of 16.5 MPa, and a voltage window of 5.07 V.
• Self-defective Si fillers facilitate Li⁺ transport and promote anion-rich solvation structures, enhancing ionic conductivity.
• The electrolytes enable stable cycling of Li||Li symmetrical batteries for over 6200 hours and fast charging in LFP||Li batteries with 82.29% capacity retention at 10 C.

Conclusions:

• Self-defective silicon fillers effectively enhance the comprehensive properties of PVDF-based electrolytes for SSLMBs.
• The developed electrolytes offer a promising pathway towards safer, high-performance solid-state batteries.
• The study highlights the potential of interface engineering in designing advanced energy storage materials.