Yang Hongxin, Zhang Yuan, Liu Zhipeng, Hu Chunfang, Li Junbiao, Liao Hailong, Shao Minhua, Ni Meng, Chen Bin, Shao Zongping, Xie Heping
State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering, Guangdong Provincial Key Laboratory of Deep Earth Sciences and Geothermal Energy Exploitation and Utilization, College of Civil and Transportation Engineering, Shenzhen University, Shenzhen, China.
CIAC-HKUST Joint Laboratory for Hydrogen Energy, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.
Nat Commun. 2025 Apr 2;16(1):3154. doi: 10.1038/s41467-025-57611-1.
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 (BaCoCeYO, 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 BaCoCeO 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.
阴极的热机械性能与高温固体氧化物燃料电池（SOFC）的耐久性密切相关，在热循环过程中主要存在两种机械故障：阴极的界面分层和体开裂。由断裂强度/刚度不足引起的体开裂是一个重大问题，但常常被忽视。在此，我们引入化学水合作用来抵消热膨胀，增强阴极的机械刚度和断裂强度，从而提高质子陶瓷燃料电池（PCFC）中阴极的热机械耐久性。这种化学诱导的膨胀抵消是通过水合后增强体阴极内部的晶界结合来实现的，从而防止热收缩过程中颗粒分离。作为一个例证，刚度增强的空气电极（BaCoCeYO，记为s-BCC-Y）的断裂强度提高了86%，因此在600至300°C之间进行35次严酷热循环后，具有热循环稳定性，几乎没有降解，超过了原始的BaCoCeO和许多无钴PCFC阴极。受益于阴极刚度的提高，采用s-BCC-Y电极的全电池显示出增强的功率输出。这项工作突出了体阴极热机械性能在开发用于高温能源应用的坚固SOFC中的重要性。
