Enhancing Fuel Cell Performance by Constructing a Gas Diffusion Layer with Gradient Microstructure.

Area of Science:

• Materials Science
• Electrochemistry
• Chemical Engineering

Background:

• Proton exchange membrane fuel cells (PEMFCs) face performance limitations due to water flooding and mass transfer issues, particularly at high current densities.
• Efficient water and gas management within the gas diffusion layer (GDL) is critical for optimal PEMFC operation.

Purpose of the Study:

• To design and fabricate a multi-scale gradient pore gas diffusion layer (GDL) for PEMFCs.
• To investigate the impact of a gradient pore structure on water flooding and mass transfer limitations.
• To enhance the overall performance and power density of PEMFCs under high current density conditions.

Main Methods:

• Fabrication of a GDL with controlled gradient pore distribution (80-170 μm) using a self-assembled mold.
• Experimental testing of PEMFCs with the gradient pore GDL under high current density conditions.
• Mechanism analysis of gas-liquid transport pathways within the optimized GDL structure.

Main Results:

• The gradient pore GDL achieved a peak power density of 1.18 W·cm⁻², a 20% improvement over traditional structures.
• The optimized structure facilitated concentrated water transport through specific channels.
• Effective gas diffusion and transport driven by concentration gradients were observed, optimizing gas-liquid management.

Conclusions:

• The multi-scale gradient pore GDL effectively addresses water flooding and mass transfer limitations in PEMFCs.
• This innovative GDL design enhances fuel cell performance and power density.
• The findings offer a significant advancement for the commercialization of PEMFC technology by improving operational stability and efficiency.