Influence of the Catalyst Layer Structure Formed by Inkjet Coating Printer on PEFC Performance

Area of Science:

• Electrochemistry
• Materials Science
• Energy Conversion

Background:

• Polymer Electrolyte Fuel Cells (PEFCs) are crucial for clean energy.
• Optimizing the Catalyst Layer (CL) structure is key to enhancing PEFC performance.
• Inkjet printing offers precise control over CL fabrication.

Purpose of the Study:

• To investigate the impact of Catalyst Layer (CL) thickness on PEFC performance.
• To examine the effect of electrode area on PEFC performance.
• To understand the microstructural changes during CL formation and their consequences.

Main Methods:

• Fabrication of Membrane Electrode Assemblies (MEAs) with varying CL thicknesses (1, 4, 5, and 6 layers).
• Evaluation of PEFC performance using overpotential analysis.
• Microstructural analysis using Energy Dispersive X-ray spectroscopy (EDX).
• Testing MEAs with different electrode areas (1 cm² and 9 cm²).

Main Results:

• Increased CL thickness led to higher activation and diffusion overpotentials.
• EDX analysis revealed platinum aggregation and poor ionomer distribution during drying, hindering the three-phase interface.
• Multilayer CLs exhibited reduced gas diffusivity compared to single-layer CLs.
• Larger electrode areas (9 cm²) resulted in higher diffusion overpotentials, exacerbating flooding/plugging issues due to condensate accumulation.

Conclusions:

• CL thickness is a critical parameter affecting PEFC performance by influencing activation and diffusion overpotentials.
• The drying process significantly impacts CL microstructure, leading to suboptimal platinum-ionomer distribution and reduced performance.
• Electrode area influences diffusion limitations and condensate management, with larger areas being more susceptible to flooding.