FC-BENTEN: Synchrotron X-Ray Experimental Database for Polymer-Electrolyte Fuel-Cell Material Analysis  
[PERSON]  
1 Japan Synchrotron Radiation Research Institute, Sayo-gun 679-5198, Japan; [EMAIL_ADDRESS] (S.Y. ); [EMAIL_ADDRESS] (T.K. ); [EMAIL_ADDRESS] (M.M. ); [EMAIL_ADDRESS] (J.K.); [EMAIL_ADDRESS] (Y.W. ); [PERSON]@springs.or (H.L. ); [PERSON]ADDRESS] (K.U. ); [PERSON]_ADDRESS] (T.U. ); [PERSON]_ADDRESS] (A.M.); [EMAIL_ADDRESS] (Y.M. ); [EMAIL_ADDRESS] (D.F. ); [EMAIL_ADDRESS] (T.M. ); [PERSON]S] (H.T.) [PERSON]  
6 [PERSON]  
6 Kumamoto Prefectal College of Technology, Kumamoto 869-1102, Japan 6  
[PERSON]  
1 Japan Synchrotron Radiation Research Institute, Sayo-gun 679-5198, Japan; [EMAIL_ADDRESS] (S.Y. ); [EMAIL_ADDRESS] (T.K. ); [EMAIL_ADDRESS] (M.M. ); [PERSON]RESS] (J.K.); [PERSON]L_ADDRESS] (Y.W. ); [PERSON]@springs.or (H.L. ); [PERSON]ADDRESS] (K.U. ); [PERSON]_ADDRESS] (T.U. ); [PERSON]@springs@.or.jp (A.M.); [PERSON]DDRESS] (Y.M. ); [PERSON]ADDRESS] (D.F. ); [EMAIL_ADDRESS] (T.M. ); [PERSON]S] (H.T.) Footnote 24: email: {Takadevelopment of polymer electrolyte fuel cells (PEFCs), Japan's New Energy and Industrial Technology Development Organization (NEDO) established an FC-Platform [1,2]. This comprehensive initiative aligns with the FAIR principles (Findable, Accessible, Interoperable, Reusable) [3] and unites specialists in electrochemical evaluation, simulation, materials analysis, materials informatics (MI), and project management. Integrating expertise across multiple domains, the FC-Platform aims to accelerate PEFC material innovation, ultimately improving the efficiency, durability, and cost-effectiveness of sustainable energy applications (Figure 1). Within the FC-Platform, SPring-8's synchrotron X-ray capabilities are tailored to address critical challenges in PEFC material research. Advanced, standardized experimental techniques enable the in situ analysis of catalytic reactions, nanoscale investigations of water and proton transport, and detailed examination of electrode interfaces under operational conditions. The resulting high-quality and reproducible data facilitate a deeper understanding of the key phenomena influencing PEFC performance. To maximize the value of these experimental datasets, SPring-8 systematically shares them with the MI group, where they are integrated with electrochemical and simulation data. This collaborative data-driven approach provides robust insights and accelerates the design of the next-generation PEFC. Recognizing the need for consistent data management and streamlined integration with broader data-driven frameworks, we developed FC-BENTEN, a dedicated synchrotron X-ray experimental database built on the existing experimental data transfer system, BENTEN [4,5]. The FC-BENTEN addresses several objectives that are critical for the advancement of PEFC research. * **Standardized and Reproducible Experimental Protocols:** FC-BENTEN ensures reliable and reproducible results at all stages of data acquisition, ranging from sample preparation to synchrotron measurements and post-experimental analysis. * **Comprehensive Measurement Coverage:** The database supports a wide array of techniques including X-ray absorption fine structure (XAFS), hard X-ray photoelectron spectroscopy (HAXPES), X-ray diffraction (XRD), pair-distribution function (PDF), and  
Figure 1: Overview of the FC-Platform, an analysis and evaluation platform for PEFCs. This figure illustrates the platform’s architecture, highlighting its role in integrating cross-disciplinary expertise and facilitating the development of advanced materials and methods for PEFCs. small-angle X-ray scattering (SAXS). These techniques yield complementary insights into the local structure, electronic states, crystallinity, and particle size distribution, thereby providing a holistic understanding of PEFC materials (Table 1). * **Metadata Consistency and Interoperability:** Rigorous metadata documentation is applied consistently, covering sample preparation, measurement conditions, data preprocessing, and analysis procedures.