SGO/SPES-based highly conducting polymer electrolyte membranes for fuel cell application

Area of Science:

• Materials Science
• Electrochemistry
• Chemical Engineering

Background:

• Proton-exchange membranes (PEMs) are critical components in fuel cells.
• Sulfonated poly(ether sulfone) (SPES) based membranes offer promise but require property enhancement.
• Direct methanol fuel cells (DMFCs) face challenges with methanol crossover and proton conductivity.

Purpose of the Study:

• To develop enhanced PEMs for DMFC applications.
• To investigate the effect of sulfonated graphene oxide (SGO) incorporation into SPES membranes.
• To evaluate the electrochemical properties and methanol crossover resistance of the composite membranes.

Main Methods:

• Composite membranes were prepared by incorporating varying amounts of SGO into SPES.
• Proton conductivity was measured at temperatures ranging from 30-90 °C.
• Methanol permeability was assessed to determine crossover resistance.
• Membrane characterization included FTIR, XRD, DSC, SEM, TEM, and AFM.

Main Results:

• Incorporation of SGO significantly increased ion-exchange capacity (IEC), water retention, and proton conductivity.
• SGO addition effectively reduced methanol permeability.
• SEM and TEM analyses confirmed uniform SGO distribution within the SPES matrix.
• The composite membrane with 5% SGO exhibited the highest proton conductivity and superior methanol crossover resistance.

Conclusions:

• The addition of SGO to SPES membranes enhances their suitability for DMFC applications.
• The 5% SGO composite membrane demonstrates an optimal balance of high proton conductivity and low methanol permeability.
• These findings highlight the potential of SGO-modified PEMs for advanced energy conversion devices.