Have proton exchange membrane fuel cells been designed for recycling?

Area of Science:

• Materials Science
• Electrochemistry
• Chemical Engineering

Background:

• Proton exchange membrane (PEM) fuel cells are widely used, necessitating effective end-of-life management strategies.
• The membrane electrode assembly (MEA), containing platinum catalysts and a Nafion membrane, is a key component requiring efficient recycling.
• Current methods primarily focus on platinum recovery, often involving harsh thermal decomposition.

Purpose of the Study:

• To develop a sustainable and efficient method for the short-loop recycling of PEM fuel cell MEAs.
• To recover platinum catalysts and Nafion membranes intact from spent MEAs.
• To evaluate the reusability of recycled components in new MEAs.

Main Methods:

• Utilizing a mixture of aqueous ethanol and isopropyl alcohol to swell and recover the PEM intact.
• Employing microwave heating in the solvent mixture to dissolve the Nafion binder and liberate platinum on carbon (Pt/C) catalysts.
• Implementing induced mixing to enhance catalyst liberation and recovery.
• Assessing the performance of recycled gas diffusion layers in newly fabricated MEAs.

Main Results:

• Achieved intact recovery of the Nafion membrane.
• Concentrated 87% of the platinum catalyst from the MEA.
• Produced clean Nafion membrane suitable for reuse.
• Demonstrated that recycled gas diffusion layers can be re-used in new MEAs with only a slight performance decrease.

Conclusions:

• The proposed method offers a viable approach for the short-loop recycling of PEM fuel cell MEAs.
• This technique efficiently recovers valuable platinum catalysts and enables the reuse of Nafion membranes and gas diffusion layers.
• Sustainable end-of-life management of PEM fuel cells can be improved through this innovative recycling process.