Hierarchical Wrinkle-Structured Catalyst Layer/Membrane Interface for Ultralow Pt-Loading Polymer Electrolyte Membrane Fuel Cells (PEMFCs)

Abstract

The optimal architecture of three-dimensional (3D) interface between a polymer electrolyte membrane (PEM) and catalyst layer (CL) is one of the most important issues to improve PEM fuel cells' (PEMFCs) performance. Here, we report the fabrication of hierarchical wrinkled PEM/CL interface over a large area. We fabricated the hierarchical wrinkles on a multiscale from nanometers to micrometers by bottom-up-based facile, scalable, and simple method. Notably, it allows one to go beyond the limit of the catalyst utilization by extremely enlarged interfacial area. The resulting hierarchical wrinkled PEM/CL displays a dramatically increased electrochemically active surface area (ECSA) and power performance by the enhancement factors of 89% and 67% compared with those of flat interface, which is one of the best enhancements compared to previous PEMFCs. We believe the scalability of hierarchical wrinkled interface can be exploited to design advanced 3D interfaces for high-performance PEMFCs even with ultralow Pt-loading.

Multiscale Architectured Membranes, Electrodes, and Transport Layers for Next‐Generation Polymer Electrolyte Membrane Fuel Cells

“…In similar work with the use of a multiscale patterned mold, recently, Lee et al. [ 92 ] reported a method for making hierarchical wrinkles patterned polymeric mold consisting of three different pattern sizes of 0.4, 3, and 10 µm by using repetitive heat‐induced mechanical deformation between a stiff top skin layer and a soft bottom. The constructed pattern was replicated by PDMS mold like the previously introduced study.…”

“…Compared with the MEA with a flat membrane, it exhibited an increment of ≈40%; its performance was also higher than that of each single-scale pattern used for constructing multiscale structures (Figure 5c). In similar work with the use of a multiscale patterned mold, recently, Lee et al [92] reported a method for making hierarchical wrinkles patterned polymeric mold consisting of three different pattern sizes of 0.4, 3, and 10 µm by using repetitive heat-induced mechanical deformation between a stiff top skin layer and a soft bottom. The constructed pattern was replicated by PDMS mold like the previously introduced study.…”

Smart Polymer Surfaces with Complex Wrinkled Patterns: Reversible, Non-Planar, Gradient, and Hierarchical Structures

“…Lee et al [ 66 ] presented the fabrication of an interface composed of a polymer electrolyte membrane (PEM) and a hierarchically wrinkled catalyst (CL) layer (PEM/CL) in a PEM fuel cell (PEMFC) by bottom-up methods ( Figure 15 ). Heat-induced repetitive mechanical deformations between a rigid top skin and a soft bottom substrate were used to fabricate these wrinkles.…”

“…( b ) Fabrication of hierarchical wrinkles through repetitive heat-induced wrinkling processes and ( c ) Transfer of wrinkled hierarchical structures to Nafion membrane by thermal lamination and subsequent CL coating. Reproduced permission from with reference [ 66 ]. Copyright 2022, American Chemical Society (ACS).…”

Micro‐/Nanohierarchical Structures Physically Engineered on Surfaces: Analysis and Perspective

“…g) Schematic illustration of catalyst layer/membrane interface using wrinkle-based hierarchical structure for ultralow Pt-loading polymer electrolyte membrane fuel cells. Reproduced with permission [28]. Copyright 2022, American Chemical Society.…”