Abstract
Roll-to-roll (R2R) slot-die coating of polymer electrolyte membrane fuel cell (PEMFC) catalyst layers represents a scalable deposition method for producing 10–20 m2·min−1 of catalyst-coated gas diffusion layers (GDLs). This high-throughput production technique will help lower the cost of PEMFC catalyst layers. The uniformity of the wet layer applied by slot die deposition is affected by process parameters such as substrate speed, vacuum pressure applied at the upstream meniscus, gap between the slot die lips and substrate, ink rheology, and other ink and substrate properties. The set of conditions for producing a defect-free coating with a dilute ink typically requires little to no upstream vacuum pressure, so suitable operating conditions can be found easily through trial and error and operator intuition. However, the higher viscosity of more concentrated inks dramatically shifts the range of settings that result in a homogeneous coating to higher vacuum levels, which are harder to find through hit or miss. A predictive model showing the range of operable conditions decreases material wastage inherent in experimentally searching for suitable parameters. In this study, the defect-free coating parameter window is explored experimentally and theoretically for two concentrations of PEFC cathode inks. Both a full capillary hydrodynamic model and a computationally cheaper viscocapillary model successfully predict the experimentally determined coating window within the experimental and model uncertainty limits for inks with 5.3 wt% and 12.0 wt% solids ink while maintaining the 0.1 mgPt·cm−2Pt areal loading target. This paper demonstrates a viable pathway for meeting the $30/kWnet ultimate cost target of the United States Department of Energy (U.S. DOE) Hydrogen Fuel Cells Technologies Office (HFTO). The concentrated ink lowers the thermal energy and capital expenditure (CapEx) budget of the coating process by decreasing the amount of time, energy, and floorspace required for drying the coating.
| Original language | English |
|---|---|
| Pages (from-to) | 474-485 |
| Number of pages | 12 |
| Journal | Journal of Colloid and Interface Science |
| Volume | 610 |
| DOIs | |
| State | Published - Mar 15 2022 |
Funding
We gratefully acknowledge Alexander Kukay for the optical profilometer measurements and Dr. Christopher Rulison at Augustine Scientific for optical tensiometer measurements. This manuscript has been authored in part by UT-Battelle, LLC, under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy (DOE) and sponsored by the Office of Energy Efficiency and Renewable Energy (EERE) Advanced Manufacturing Office (AMO) (Program Managers: David Hardy and Brian Valentine). Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525. A portion of this research was conducted at Saint-Gobain Research North America under contract DE-EE0008323. The U.S. government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan ( http://energy.gov/downloads/doe-public-access-plan ). We gratefully acknowledge Alexander Kukay for the optical profilometer measurements and Dr. Christopher Rulison at Augustine Scientific for optical tensiometer measurements. This manuscript has been authored in part by UT-Battelle, LLC, under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy (DOE) and sponsored by the Office of Energy Efficiency and Renewable Energy (EERE) Advanced Manufacturing Office (AMO) (Program Managers: David Hardy and Brian Valentine). Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC. a wholly owned subsidiary of Honeywell International, Inc. for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-NA0003525. A portion of this research was conducted at Saint-Gobain Research North America under contract DE-EE0008323. The U.S. government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/downloads/doe-public-access-plan).
Keywords
- Cathode catalyst layer
- Gas diffusion electrode
- Proton exchange membrane fuel cell
- Roll-to-roll manufacturing
- Slot-die coating
