Poly(dimethyl siloxane) membrane for high temperature proton exchange membrane fuel cells

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Chemistry

Background:

• Sulfonic acid membranes require water for conductivity, limiting high-temperature applications.
• Phosphoric acid offers proton conductivity without water, ideal for high-temperature proton exchange membrane fuel cells (PEMFCs).

Purpose of the Study:

• To synthesize a thermally stable, amphiphilic membrane with phosphorous groups for high-temperature PEMFCs.
• To investigate the proton conductivity and thermal stability of the novel membrane under dry conditions.

Main Methods:

• Modification of hydrophobic poly(dimethyl siloxane) (PDMS) with hydrophilic phosphorous groups.
• Inducing phase separation to create proton-conducting channels within the membrane.
• Characterizing proton conductivity at elevated temperatures and under dry conditions.

Main Results:

• The synthesized membranes demonstrated constant proton conductivity above 130°C under dry conditions.
• The material exhibited excellent thermal stability, withstanding temperatures up to 300°C.
• Phase separation successfully formed distinct proton-conducting channels.

Conclusions:

• The novel phosphorous-functionalized PDMS membrane is suitable for high-temperature PEMFCs operating under low humidity.
• The material offers a promising alternative to traditional membranes for demanding fuel cell applications.