Solid Polymer Electrolytes with Dual Anion Synergy and Twofold Reinforcement Effect for All-Solid-State Lithium...

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Chemistry

Background:

• Solid polymer electrolytes (SPEs) offer a safer alternative to liquid electrolytes in lithium batteries.
• Poly(ethylene oxide) (PEO)-based SPEs show promise but suffer from low ionic conductivity and poor dimensional stability.
• Developing robust SPEs is crucial for advancing high-energy density lithium battery technology.

Purpose of the Study:

• To develop advanced solid polymer electrolytes with improved ionic conductivity and dimensional stability.
• To enhance lithium dendrite suppression for safer lithium battery operation.
• To investigate the synergistic effects of ionic liquid monomers and polymer networks in SPEs.

Main Methods:

• Synthesized styrenic-DABCO-based ionic liquid monomers (SDTFSI, SDFSI) with TFSI- or FSI- anions.
• Incorporated ionic liquid precursors and PEO into electrospun poly(acrylonitrile) (PAN) fibrous mats.
• Utilized thermal-initiated cross-linking to form a semi-interpenetrating polymer network (semi-IPN) structure.

Main Results:

• Achieved dimensionally stable SPEs with excellent flexibility, stable up to 150 °C.
• Demonstrated ionic conductivity of 4.4 × 10⁻⁴ S cm⁻¹ at 25 °C and 1.81 × 10⁻³ S cm⁻¹ at 55 °C.
• Observed enhanced lithium dendrite suppression due to synergistic effects of FSI-/TFSI- anions and the semi-IPN/PAN network.

Conclusions:

• The developed semi-IPN SPEs exhibit superior ionic conductivity and dimensional stability compared to traditional PEO-based electrolytes.
• The unique structure effectively suppresses lithium dendrite growth, enhancing battery safety.
• These findings pave the way for high-performance and safer lithium batteries utilizing advanced polymer electrolytes.