Advanced Sulfonated Poly(Ether Ether Ketone)/Graphene-Oxide/Titanium Dioxide Nanoparticle Composited Membrane with...

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Vanadium ion crossover is a major challenge in vanadium redox flow batteries (VRFBs).
• Sulfonated poly(ether ether ketone) (SPEEK) membranes suffer from significant vanadium ion permeability.
• Improving membrane selectivity is crucial for efficient and durable VRFB energy storage.

Purpose of the Study:

• To enhance the vanadium ion repulsion of SPEEK membranes.
• To develop a novel hybrid membrane for improved VRFB performance.
• To investigate the effect of graphene oxide and titanium dioxide on membrane properties.

Main Methods:

• Fabrication of SPEEK/GO/TiO₂ hybrid membranes using a solution-casting method.
• Characterization of membrane morphology and vanadium ion permeability.
• Evaluation of VRFB single cell performance using the developed hybrid membranes.

Main Results:

• The SPEEK/GO/TiO₂ hybrid membrane demonstrated a barrier effect, reducing vanadium ion crossover.
• Optimized hybrid membranes achieved high coulombic efficiency (~99%) and energy efficiency (~85%).
• The hybrid membrane exhibited excellent cyclability with ~97.2% capacity retention after 100 cycles and lower vanadium ion permeability than Nafion 212 and pure SPEEK.

Conclusions:

• The incorporation of graphene oxide and titanium dioxide significantly improves the comprehensive properties of SPEEK membranes.
• The developed hybrid membrane offers a promising alternative for VRFB energy storage systems due to enhanced performance and durability.
• SPEEK/GO/TiO₂ hybrid membranes show superior ion selectivity and stability compared to conventional membranes.