Fluorinated Poly(ionic liquid) Diblock Copolymers Obtained by Cobalt-Mediated Radical Polymerization-Induced...

Area of Science:

• Polymer Chemistry
• Materials Science
• Electrochemistry

Background:

• Poly(ionic liquid)s (PILs) are emerging as promising single-ion solid polyelectrolytes (SPEs).
• Conventional electrolytes face limitations in electrochemical devices.
• Novel PIL-based amphiphilic diblock copolymers (BCPs) offer potential for improved SPE performance.

Purpose of the Study:

• To precisely synthesize and characterize a novel double PIL-based amphiphilic diblock copolymer (BCP).
• To evaluate the BCP as a single-ion SPE for electrochemical applications.
• To investigate the ionic conductivity, electrochemical stability, and mechanical properties of the synthesized SPE.

Main Methods:

• One-pot cobalt-mediated radical polymerization-induced self-assembly (CMR-PISA) in water for BCP synthesis.
• Anion exchange reaction to substitute bromide with bis(trifluoromethylsulfonyl)imide (Tf2N-) counter-anions.
• Broadband dielectric spectroscopy and stress/strain experiments for characterization.

Main Results:

• Synthesized amphiphilic PIL BCPs with controlled block lengths.
• Achieved ionic conductivity (σDC) of 1-3 × 10⁻⁷ S cm⁻¹ at 30 °C under anhydrous conditions.
• Demonstrated wide electrochemical stability (up to 4.8 V vs. Li⁺/Li) and suitable mechanical properties (Young's modulus = 3.8 MPa, elongation at break = 250%).

Conclusions:

• The novel PIL BCPs are effective single-ion SPEs.
• The synthesized materials exhibit promising properties for electrochemical devices.
• The CMR-PISA method provides a viable route for creating advanced SPE materials.