Hydration-induced stiffness enabling robust thermal cycling of high temperature fuel cells cathode

Abstract Thermo-mechanics of cathode is closely related to the durability of high-temperature solid oxide fuel cells (SOFCs), with two main mechanical failures during thermal cycling: interface delamination and bulk cracking of cathode. Bulk cracking, caused by insufficient fracture strength/stiffne...

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Bibliographic Details
Main Authors: Hongxin Yang, Yuan Zhang, Zhipeng Liu, Chunfang Hu, Junbiao Li, Hailong Liao, Minhua Shao, Meng Ni, Bin Chen, Zongping Shao, Heping Xie
Format: Article
Language:English
Published: Nature Portfolio 2025-04-01
Series:Nature Communications
Online Access:https://doi.org/10.1038/s41467-025-57611-1
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Summary:Abstract Thermo-mechanics of cathode is closely related to the durability of high-temperature solid oxide fuel cells (SOFCs), with two main mechanical failures during thermal cycling: interface delamination and bulk cracking of cathode. Bulk cracking, caused by insufficient fracture strength/stiffness is a big concern but often overlooked. Here, we introduce chemical hydration to offset the thermal expansion, enhancing the cathodic mechanical stiffness and fracture strength, thus promoting the thermo-mechanical durability of cathode in proton ceramic fuel cells (PCFCs). Such chemical-induced expansion offset is achieved by strengthening intergranular bonding inside the bulk cathode after the hydration, preventing granule detachment during thermal shrinkage. As a demonstration, the stiffness-enhanced air electrode (BaCo0.7Ce0.15Y0.15O3, noted as s-BCC-Y) exhibits 86% enhancement of fracture strength, thus thermal cycling stability with almost no degradation after 35 harsh thermal cycles between 600 and 300 °C, surpassing pristine BaCo0.7Ce0.3O3 and many cobalt-free PCFC cathodes. Benefitted from the improved stiffness of cathode, full cell with the s-BCC-Y electrode demonstrates enhanced power output. This work highlights the importance of bulk cathode thermo-mechanics in developing robust SOFCs for high temperature energy applications.
ISSN:2041-1723