Ultra‐low Mass Sputtered and Conventional Catalyst Layers on Plasma‐etched Nafion for PEMFC Applications

Abstract

This paper presents performance results for the use of plasma‐etched Nafion membranes to suppress polarization losses in proton exchange membrane fuel cells (PEMFCs) configured from 0.1 mg cm−2 conventional Pt/C dispersion and 0.02 mg cm−2 ultra‐thin sputter‐deposited Pt catalyst layers. Four MEA configurations, namely, etched membrane‐conventional electrode, pristine membrane‐conventional electrode, etched membrane‐sputter electrode, and pristine membrane‐sputter electrode cells were explored, and their respective maximum power densities were ∼514.6, 417.9, 170.1 and 138.3 mW cm−2. The results demonstrated that independent of MEA fabrication approach, cells with O2 plasma treated membranes had reduced ohmic resistances and delivered superior performance over their pristine counterparts, validating the utility of membrane etching for achieving improved PEMFC performance.

Mechanically Stable Thinned Membrane for a High-Performance Polymer Electrolyte Membrane Fuel Cell via a Plasma-Etching and Annealing Process

“…Nonetheless, the surface of E-N212 with a thickness of ∼25 μm was irregular and rugged, as seen in Figure b, which indicated that plasma treatment not only decreased membrane thickness but also modified the surface topography. Specifically, we observed that the root-mean-square (RMS) factor, which reflects the extent of surface roughness, increased dramatically from 1.61 to 331 nm and this is consistent with the previous plasma etching studies. − ,, To investigate the surface morphology change depending on the annealing temperature, we have varied annealing temperatures. It has been reported that the Nafion membrane has two kinds of glass transition temperatures ( T g ).…”

“…Specifically, we observed that the root-mean-square (RMS) factor, which reflects the extent of surface roughness, increased dramatically from 1.61 to 331 nm and this is consistent with the previous plasma etching studies. [14][15][16]27,28 To investigate the surface morphology change depending on the annealing temperature, we have varied annealing temperatures. It has been reported that the Nafion membrane has two kinds of glass transition temperatures (T g ).…”

“…First, Nafion composite membranes with blending various metal oxides − or other polymers , have been fabricated to sustain high performance at higher operating temperature and pressure . As a physical approach, making a thinned Nafion membrane has been attempted to attain high proton conductivity by applying sand-blasting, ion-bombardment, or plasma etching. − Interestingly, surface nanoroughness resulted from plasma etching showed an effective role to enlarge the interface area between the electrode and the membrane, where the electrochemical reaction occurs most actively . However, the relationship between mechanical properties and morphological changes on the surface should be addressed in more detail since the reduced thickness and high roughness caused by plasma etching can easily induce stress-concentration and crack propagation, which deteriorate the membrane durability.…”

Preparation, Performance and Challenges of Catalyst Layer for Proton Exchange Membrane Fuel Cell

“…However, both of these processes are based on the two-dimensional flat membranes. In recent years, many new and improved technologies have tried to replace the commonly used flat membrane but forming various patterns on the membrane started to be considered from a three-dimensional perspective with the interface characteristics of PEM|CL [75][76][77][78][79][80].…”

Fast Proton Conduction in Denatured Bovine Serum Albumin-Coated Nafion Membranes

“…Proton conduction is one of the common natural processes and very important in life activities, such as proton translocation by the adenosine triphosphate synthase complex and the proton transfer in biochemical processes. − It is well-known that protons can be conducted laterally along the membranes or by specific amino acids such as the proton pump activity of bacteriorhodopsin protein. − Beyond biochemical systems, proton conduction also plays an important role in electrochemical devices, like sensors, batteries, and fuel cells for instance. − Solid proton exchange membranes (PEMs) are commonly used in these devices, where protons are transported through the membranes. , Therefore, PEMs need to possess high proton conductivity, selectivity, and mechanical stability. Perfluorinated ionomers, especially Nafion, are widely used as PEM materials for fuel cells. − Nafion is composed of a hydrophobic tetrafluoroethylene-like backbone and side chains terminated with hydrophilic sulfonic groups . Strongly acidic sulfonic groups, when hydrated, combine with water molecules and ionize, so that proton conduction channels form with connected sulfonic ionic clusters ((−SO 3– ) n ).…”