Superior Ionic Transferring Polymer with Silicon Dioxide Composite Membrane via Phase Inversion Method Designed for...

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Polypropylene membranes are conventional separators in batteries.
• Poly(vinyledene fluoride) (PVdF) shows promise for polymer electrolyte membranes due to its high dielectric constant.
• Developing advanced separators is crucial for improving battery performance.

Purpose of the Study:

• To prepare a novel poly(vinyledene fluoride)-silicon dioxide (PVdF-SiO2) composite separator membrane.
• To investigate the morphology, porosity, and electrochemical properties of the composite membrane.
• To evaluate the potential of this composite membrane as an alternative to conventional polypropylene separators.

Main Methods:

• Phase inversion method was used to prepare the PVdF-SiO2 composite membrane.
• Electrolyte uptake and temperature-dependent ionic conduction were tested using 1 M NaPF6.
• Physical properties were analyzed using X-ray diffraction, FT-IR, and FE-SEM.
• Electrochemical performance was assessed via impedance analysis with a P2-type sodium cathode.

Main Results:

• The PVdF-SiO2 composite membrane exhibited high ionic conductivity of 4.7 × 10^-2 S cm^-1 at room temperature.
• The membrane demonstrated excellent electrochemical performance when paired with a P2-type sodium cathode.
• An initial discharge capacity of 178 mAh g^-1 with 98% coulombic efficiency was achieved.
• The composite separator retained 81% of its capacity after 50 cycles.

Conclusions:

• The PVdF-SiO2 composite separator membrane is a viable and superior alternative to conventional polypropylene membranes.
• The developed membrane shows significant potential for enhancing the performance of sodium-ion batteries.
• The simple phase inversion method provides a scalable route for producing these advanced battery separators.