Structural and Electrochemical Investigation of Anode‐Supported Proton‐Conducting Solid Oxide Fuel Cell Fabricated by the Freeze Casting Process

• Published in: Fuel cells (Weinheim an der Bergstrasse, Germany) Vol. 24; no. 4
• Main Authors: Karimi, Ali, Paydar, Mohammad Hossein, Aghaei, Hamed, Masoumi, Hossein
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 01.08.2024
• Subjects: Anodic polarization; Cerium oxides; Computed tomography; Diffusion layers; Electrochemical impedance spectroscopy; Electrode polarization; freeze casting; Gadolinium; Gaseous diffusion; Image processing; Maximum power; power density; Pressing; proton conductor; Protons; solid oxide fuel cell; Solid oxide fuel cells; Solidification; Tomography; Tortuosity
• ISSN: 1615-6846; 1615-6854
• DOI: 10.1002/fuce.202300200

ABSTRACT Hierarchically oriented macroporous NiO–BaZr0.1Ce0.7Y0.2O3−δ (BZCY7) anode‐supporting layer (ASL) was developed using the freeze casting technique. The resulting freeze‐cast structure was analyzed through scanning electron microscopy and X‐ray computed tomography. A thin layer of BZCY7 was utilized as a proton‐conducting electrolyte, whereas La1.9Sr0.1Ni0.7Cu0.3O3−δ –gadolinium‐doped ceria 10% Gd (LSNC–GDC10) was employed and evaluated as cathode layer. The performance of the cell was assessed by means of electrochemical impedance spectroscopy and I–V–P curves at various temperatures. Furthermore, as a point of comparison, a cell with an ASL was prepared using the dry pressing method, incorporating 20 wt.% graphite as a pore‐forming agent. The freeze‐cast anode‐supported cell demonstrated a polarization resistance of 1.45 Ω cm2 at 550°C and 0.29 Ω cm2 at 750°C. Maximum achieved power densities were 0.189 and 0.429 W cm−2 at 550 and 750°C, respectively. For the cell fabricated by the dry pressing method, the maximum power densities were 0.158 and 0.397 W cm−2 at 550 and 750°C, respectively. Additionally, the tortuosity factor of the anode layer and the gas diffusion streamline in the direction of solidification were determined by using 3D X‐ray tomography imaging and subsequent image processing.