Low temperature sintering assistant-preparation of LSGM electrolyte for solid oxide fuel cells deposited by vacuum cold spray

Intermediate solid oxide fuel cell (IT-SOFC), which operates at lower temperature to reduce cost and improve efficiency, had received certain attention in recent years. Vacuum cold spray (VCS), facilitating in forming thin ceramic film based on the impact adhension of fine particles at room temperature, is therefore a new and promising method to fabricate electrolyte membrane of SOFC. However, a dense VCS-prepared coating is primarily dependent on a optimized combination of powder size range and particle velocity, which limits the application of VCS on SOFC. In this study, the VCS-prepared LSGM electrolyte was further densified assistant with low temperature sintering. LSGM electrolytes with different thickness, were fabricated by vacuum cold spray following by sintering at 1200 °C to further densify the coating. After sintering, the coating become densier in most regions due to the grain growth from one hundred nanometers to micro-scale accompanying with the appearance of some cracks in local regions of the coating surface due to thermal mismatch and constrained sintering. Therefore, the second layer was deposited on the annealed coatings to block those cracks. Then the two-layer structure was co-sintered to further densify the coating. The test results of gas permeability of the obtained coatings demonstrate that the films are dense enough to act as the electrolyte of SOFC. The output performance of cell was also tested at 600-800 °C with LSCF cathode layer deposited by air plasma spray (APS).