(591k) Template-Based Structured Electrodes for High Power and Durable Fuel Cells

As global interests towards commercialization of proton exchange membrane fuel cells (PEMFCs) are unprecedentedly strong, there is an urgent need to address challenges related to cost, performance, and durability.¹ The membrane electrode assembly (MEA) is a critical component of PEMFCs; however, conventional cathode electrode is severely limited by poor transport properties and low electrochemical surface area, due to its randomly distributed components and tortuous transport pathways.² Beyond the search for Pt-based catalysts with high specific activity, the design of micropatterned electrodes to enhance Pt utilization has been a major approach for advancing high-performance and low-cost PEMFCs.³

In this presentation, we propose a single-step fabrication of micropatterned templates combined with hot pressing to produce an array of membrane pillars. By applying silane treatment to the templates to lower the surface energy of the template, the patterned membrane can be easily peeled off (rather than dissolved away), enabling reuse of the template after cleaning. In addition, we optimized the hot-pressing temperature and pressure, allowing the patterns on the template to be rapidly transferred to the proton exchange membrane with high fidelity. After successful fabrication of the membrane, we also explored various coating methods to ensure optimal coating of catalyst on the patterned membrane surface. Unlike conventional spray coating,⁴ these coating methods are designed to form patterned catalyst layers that avoid filling the gaps between the membrane pillars, allowing us to further enhance catalyst utilization and electrode performance.

The results of our works demonstrate that the templating method enables fast, efficient, and simple fabrication of micropatterned electrodes, offering a promising design strategy for a new class of high-power and durable electrode architectures for next-generation PEMFCs.

References:

1. Jiao et al., Nature volume 595, pages 361–369 (2021).
2. Yang et al., Energy Rev. 7, 9 (2024).
3. Lee et al., Nature Energy volume 8, pages 685–694 (2023).
4. Koh et al., Journal of Materials Chemistry A23, 8652-8659 (2014).