Fluoride Graphdiyne Enhances Polymer Electrolytes Through Regional Electric Potential Synergies for High-Performance...

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Solid-state polymer electrolytes (SSPEs) are crucial for all-solid-state lithium-metal batteries (ASSLMBs).
• Challenges include low ionic conductivity, poor transference numbers, and interfacial issues due to uncoordinated component interactions.
• Existing SSPEs often struggle with dendrite formation and limited operational stability.

Purpose of the Study:

• To enhance the performance of PVDF-HFP/LiTFSI based SSPEs using fluoride graphdiyne (FGDY) as a nanofiller.
• To investigate the mechanism of regional electric potential synergies (REPS) in improving SSPE properties.
• To demonstrate the efficacy of FGDY in promoting Li-ion transport and interfacial stability in ASSLMBs.

Main Methods:

• Incorporation of fluoride graphdiyne (FGDY) as a nanofiller into a PVDF-HFP/LiTFSI polymer electrolyte system.
• Characterization of the electrolyte's ionic conductivity, Li-ion transference number, and interfacial properties.
• Fabrication and testing of Li//LiFePO4 and Li//LiNi0.6Co0.2Mn0.2O2 full cells using the modified SSPE.

Main Results:

• FGDY nanofillers effectively promoted LiTFSI dissociation and accelerated Li-ion migration via REPS.
• A uniform LiF-rich solid electrolyte interphase was formed, inhibiting lithium dendrite growth and ensuring interfacial stability.
• The assembled full cells demonstrated excellent reversible capacity and stable cycling performance at 30°C.

Conclusions:

• Fabricating nanofillers with ordered electric potential difference regions is a viable strategy to improve SSPE performance.
• FGDY acts as an effective nanofiller, optimizing SSPEs through REPS for enhanced ASSLMB applications.
• This approach offers significant potential for the practical application of advanced all-solid-state lithium-metal batteries.