Toyota Central R&D Labs, Inc., the Japan Atomic Energy Agency (JAEA) J-PARC Center, and Comprehensive Research Organization for Science and Society (CROSS) formed a research group that developed a technology to distinguish between water and ice insid large fuel cells. We achieved this using the "RADEN" neutron imaging device within a large-scale environmental simulation chamber operating below freezing temperatures at the Materials and Life Science Experimental Facility (MLF) of the Japan Proton Accelerator Research Complex (J-PARC). The process by which water freezes inside an in-vehicle fuel cell during power generation and its effect on the cell's performance has been elucidated. This technology is expected to improve the performance of vehicle fuel cells further.. For the full text, please refer to the link above.

Key Research Points

  • Commercial fuel cell electric vehicles prevent performance degradation caused by freezing during sub-zero cold starts by using the heat generated during power generation. However, developing more efficient cold start methods requires direct observation of the fuel cell's interior while operating in sub-zero environments in order to understand how water freezes. 
  • Leveraging the ability of neutron beams to distinguish between water and ice, the team developed a technique to identify and visualize water and ice within large automotive fuel cells at sub-zero temperatures. This was achieved by combining a large-area pulsed neutron beam with a large-scale environmental simulation apparatus.
  • As a result, the process by which water freezing inside an in-vehicle fuel cell during power generation affects its performance has been clarified.
  • This achievement is expected to lead to various advancements in fuel cell research and development, such as optimizing startup methods below freezing and designing and verifying concepts for materials and flow paths.

Title: Experimental Visualization of Water/Ice Phase Distribution at Cold Start for Practical-sized Polymer Electrolyte Fuel Cells
Authors: Yuki Higuchi*1, Wataru Yoshimune*1, Satoru Kato*1, Shogo Hibi*1, Daigo Setoyama*1, Kazuhisa Isekawa*1*3  , Yoshihiro Matsumoto*2, Hiroshi Hayashida*2, Hiroshi Nozaki*1, Masashi Harada*1, Tokuhiro Fukaya*1, Takanori Suzuki*1, Takehisa Shinohara*3, Yasutaka Nagai*1 　
 *1: Toyota Central R&D Labs, Inc., *2: National Institute for Materials Science, *3: Japan Atomic Energy Agency
Journal Name: Communications Engineering
Published: February 19, 2024 (Online)
https://doi.org/10.1038/s44172-024-00176-6