This paper describes the development of mass-production technology for membrane-electrode assemblies (MEA) with a radical capturing layer and verifies its performance. Some of the authors of this paper previously developed an MEA with a radical capturing layer along the boundaries between the electrode catalyst layer and the polymer membrane to realize an endurance time of 20,000 h in accelerated daily start and daily stop (DSS) deterioration tests. Commercialization of these MEAs requires a production technology that suits mass production lines and provides reasonable cost performance. After developing a water-based slurry and selecting a gas diffusion layer (GDL), a catalyst layer forming technology uses a rotary screen method for electrode formation. Studies confirmed continuous formation of the catalyst layer, obtaining an anode/cathode thickness of 55 μm (+10/−20)/50 μm (+10/−20) by optimizing the opening ratio and thickness of the screen plate. A layer-forming technology developed for the radical capturing layer uses a two-fluid spraying method. Continuous formation of an 8 μm thick (±3 μm) radical capturing layer proved feasible by determining the appropriate slurry viscosity, spray head selection, and optimization of spraying conditions.
Local degradation effects in automotive size membrane electrode assemblies under realistic operating conditions
