Progress of interface modification on cathode for low to intermediate temperature solid oxide fuel cell

Under the goal of CO2 emissions peak and carbon neutrality, it urgently needs to improve the utilization efficiency of coal and reduce CO2 emissions in China. Solid oxide fuel cells (SOFC) are power generation devices that convert the chemical energy of fuel directly into electrical energy. The conventional SOFC generally requires high operating temperatures of about 800-1 000 ℃, which will cause severe problems such as increased system cost, performance degradation of the material, element diffusion and reaction between components, etc. Developing low to intermediate temperature SOFC is an inevitable choice for its application. However, the sluggish oxygen reduction reaction(ORR) process and instability at the cathode are the major challenges that limit the development of SOFC. Surface structural modifications of the cathode are considered to be the most effective strategy to improve performance. Designing surface structural modifications is believed to be the most effective strategy to accelerate cathodic ORR dynamics and cell performance, which can efficiently increase the triple-phase boundaries and provide more active sites. By surface modification, the coarsening of cathode particles and the phase insulation are restricted, and the cell life is improved. The techniques for cathode interface modification are introduced in detail. The structure types of modified interfaces (composite structure, membrane interface structure, skeleton/surface coating structure), three cathode interface modification technologies(atomic layer deposition, pulsed laser deposition and wet infiltration), and the effects of cathode interface modification on oxygen ion transport, catalytic activity, and stability are reviewed. Then the problems and challenges of cathode interface modification are discussed, and the possible strategies to overcome these problems are also discussed. It also provides valuable guidance for the reasonable design of cathode electrode material and structure and lay the foundation for the practical application of SOFC. © 2022 China Coal Society. All rights reserved.