A Wettability Evaluation Method for Fuel Cell Materials

A study conducted by Wataru Yoshimune et al., was published in the ACS Applied Materials & Interfaces.

Porous carbon paper is used as a fuel cell electrode to provide both electrical conductivity and gas diffusivity. This carbon paper is typically waterproofed to prevent water from accumulating in its micropores during power generation. However, excessive use of the waterproofing agent can reduce electron conductivity due to its insulating properties. Therefore, accurate wettability evaluation techniques are essential to optimize the amount of waterproofing agent used.

Conventional wettability evaluation methods, which are based on observing the shape of water droplets on the surface, effectively measure surface wettability but cannot assess wettability within the porous structure of carbon paper. In this study, we propose a method to evaluate the internal wettability of carbon paper using electrochemical techniques and synchrotron X-ray characterization. The results indicated that carbon paper treated with a small amount of waterproofing agent exhibited surface water repellency but did not exhibit water repellency within the internal structure. This method will aid in the development and production of fuel cell materials by optimizing the amount of waterproofing agent used.

Title: Comprehensive Analysis of Wettability in Waterproofed Gas Diffusion Layers for Polymer Electrolyte Fuel Cells
Authors: Yoshimune, W., Kato, A., Yamaguchi, S., Hibi, S., Kato, S.
Journal Name: ACS Applied Materials & Interfaces
Published: July 4, 2024
https://doi.org/10.1021/acsami.4c07867