@article{ZHU2025, 
author = {Tenglong ZHU and Qi HE and Qiuqiu LYU and Qin ZHONG},
title = {Research Progress on Cathode Contact Components for Solid Oxide Fuel Cell},
year = {2025},
journal = {Journal of the Chinese Ceramic Society},
volume = {53},
number = {10},
pages = {3031-3040},
keywords = {solid oxide fuel cell, cathode contact assembly, contact resistance, preparation process, numerical simulation},
url = {https://www.sciopen.com/article/10.14062/j.issn.0454-5648.20240730},
doi = {10.14062/j.issn.0454-5648.20240730},
abstract = {Solid oxide fuel cells (SOFCs) represent a highly efficient energy conversion technology capable of directly transforming chemical energy from fuels into electricity, with single-cycle efficiencies ranging from 40% to 60% and combined heat-and-power efficiencies reaching up to 60%–90%. Among various SOFCs configurations, planar SOFCs stacks become popular due to their high-power density, modular design, and flexible assembly. However, the compact structure of planar stacks imposes stringent requirements on assembly precision, often leading to a poor "solid-solid" interfacial contact between ceramic single cells and metallic interconnects. This issue results in high internal resistance, reduced output performance, and compromised long-term stability. To address these challenges, cathode contact components are introduced between the single cell and interconnect to optimize interfacial contact, ensuring stable electron transport pathways and mitigating mechanical stress during operation.The selection and design of cathode contact materials are critical, requiring a balance of high electrical conductivity, chemical stability, thermal expansion coefficient (TEC) compatibility with adjacent components, sufficient porosity for gas diffusion, mechanical strength, and cost-effectiveness. While anode-side contact materials (e.g., nickel mesh or foam) perform well under reducing atmospheres, cathode-side materials face harsher conditions due to high-temperature oxidative environments and the inherent brittleness of ceramic oxides. Consequently, cathode contact materials must meet more rigorous criteria to minimize contact resistance and ensure durability.This review represents the selection of contact materials, analyzes the influencing factors of contact resistance, and introduces the relevant preparation processes. In terms of material selection, precious metals possess excellent electrical conductivity and sintering activity. However, aside from silver, the material costs are relatively high. Silver itself also faces some issues such as volatility at high temperatures. Perovskite materials have low cost and high stability in cathodic environment, and material systems such as La0.8Sr0.2CoO3 (LSC), La0.8Sr0.2Co0.8Fe0.2O3-δ (LSCF), La0.8Sr0.2MnO3 (LSM), LaNi0.6Fe0.4O3−δ (LNF), and LaNi0.6Fe0.4O3(LCN) are used as contact materials for research, and the research goal is how to achieve the trade-off between conductivity, TEC, and sintering activity, and the ASR change during long-term isothermal and thermal cycling is also a key issue. Spinel material is more used in the coating of the linker, which is important in preventing the migration of Cr and protecting the blocker against oxidation. The development of composite materials combines the excellent properties of different materials. For instance, LSCF-Ag composites exhibit a reduced interfacial resistance and an enhanced long-term stability.Contact resistance is an important factor that affects the overall performance of the battery stack, and the factors influencing contact resistance mainly include interface contact effects, contact area, load strength, elastic modulus, and temperature. Balancing electronic transport and gas diffusion is crucial as excessive contact area under low oxygen conditions may hinder the diffusion of oxygen. The existing research focuses on studying the effects of various factors on contact resistance and battery performance through the combination of experiments and numerical simulations. This integration serves as a mutual validation, enhancing the reliability of the results, saving time and costs, as well as providing a deeper understanding of the underlying physical mechanisms. In terms of the preparation process, in addition to the commonly used methods such as screen printing, spraying, and casting, some novel forming techniques are also applied in the preparation of contact components, such as laser scanning technology, electrophoretic deposition, physical vapor deposition, and magnetron sputtering, each with its own advantages and disadvantages.Summary and ProspectsCathode contact components play a pivotal role in determining the efficiency, reliability, and longevity of SOFC stacks. The future development of cathode contact components may focus on several aspects, the first of which is the development of new materials. Innovative cathode materials can be used for the cathode itself and served as candidate materials for the cathode contact layer. It is important to optimize the preparation process. Lab-scale studies can explore various novel or established preparation techniques. However, in industrial production, the choice of preparation processes is constrained by sample stability and cost. Therefore, optimizing the preparation process to compensate for some inherent shortcomings of the materials is a direction worthy of research. Furthermore, the study of contact components will become more complex when considering the actual operating conditions within the stack, such as flow field distribution, temperature distribution, and current distribution. In terms of structural design, concepts such as gradient configuration and asymmetric structures can be applied to achieve the overall performance and structural stability.In summary, some challenges remain in achieving large-scale commercialization while significant progress is made in cathode contact materials and components. Collaborative efforts integrating material science, engineering, and computational modeling will be a key to advancing SOFCs technology toward widespread adoption in clean energy systems.}
}