Self-Healing Sulfonated Poly(ether ether ketone)-Based Polymer Electrolyte Membrane for Direct Methanol Fuel Cells:...

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Proton exchange membranes (PEMs) are crucial for fuel cell technology.
• Nafion, a common PEM in direct methanol fuel cells (DMFCs), exhibits high proton conductivity but also high methanol permeability and degradation issues.
• There is a need for advanced PEMs with enhanced durability and methanol barrier properties.

Purpose of the Study:

• To develop a novel, healable PEM by blending sulfonated poly(ether ether ketone) (SPEEK) and poly-vinyl alcohol (PVA).
• To investigate the impact of N,N-dimethylacetamide (DMAc) solvent concentration on membrane properties.
• To optimize PEM performance for improved durability and methanol resistance in DMFCs.

Main Methods:

• Fabrication of SPEEK/PVA blend membranes using varying DMAc solvent concentrations.
• Characterization of membrane properties, including water absorption, proton conductivity, and methanol permeability.
• Evaluation of the self-healing capacity and durability of the developed membranes.

Main Results:

• Lower DMAc concentrations enhanced water absorption and proton conductivity, but increased methanol permeability.
• The blend membrane with 10 wt% DMAc solvent (SP10) demonstrated the best trade-off, achieving high selectivity.
• SP10 exhibited significant self-healing, recovering 88% of its methanol-blocking efficiency, with healing capacity decreasing at higher solvent concentrations.

Conclusions:

• Optimizing DMAc solvent concentration is critical for tailoring PEM performance in DMFCs.
• The developed SPEEK/PVA blend membrane possesses excellent methanol barrier and self-healing characteristics.
• This pioneering membrane offers potential for efficient and durable fuel cell systems.