Lithium-Rich Porous Aromatic Framework-Based Quasi-Solid Polymer Electrolyte for High-Performance Lithium Ion...

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Chemistry

Background:

• Solid polymer electrolytes (SPEs) are crucial for high-energy solid lithium-ion batteries (SLIBs), requiring high ionic conductivity, electrochemical stability, and mechanical strength.
• Porous aromatic frameworks (PAFs) offer high porosity, tunable structures, and mechanical stability, making them promising candidates for SPEs.

Purpose of the Study:

• To develop a novel PAF-based quasi-solid polymer electrolyte (PAF-QSPE) for SLIBs.
• To enhance Li+ transport, ionic conductivity, and electrochemical performance using a lithium-rich amidoxime-modified PAF.

Main Methods:

• Synthesized a lithium-rich amidoxime-modified porous aromatic framework (PAF-170-AO) by absorbing LiTFSI.
• Compounded PAF-170-AO with PVDF-HFP and a minimal amount of plasticizer to create the PAF-QSPE.
• Characterized the ionic conductivity, Li+ transference number (tLi), activation energy, and electrochemical performance of the assembled SLIBs.

Main Results:

• The PAF-QSPE achieved a high ionic conductivity of 1.75 × 10⁻⁴ S cm⁻¹ and a tLi of 0.55 at room temperature with low activation energy (0.136 eV).
• The amidoxime groups facilitated Li+ dissociation and migration while suppressing anion movement and lithium dendrite growth.
• The assembled SLIBs demonstrated a discharge capacity of 163 mAh g⁻¹ at 0.2 C and excellent cycling stability with 96% capacity retention after 350 cycles.

Conclusions:

• Lithium-rich amidoxime-modified PAFs are highly effective in improving the performance of quasi-solid polymer electrolytes.
• The developed PAF-QSPE shows significant potential for practical application in high-energy-density SLIBs.
• This approach offers a promising strategy for designing advanced electrolytes for next-generation lithium batteries.