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This study adopts a novel structure design of large-area planar metal-supported solid oxide fuel cell (MS-SOFC), which exhibits the characteristics of self-sealing and high thermal cycling resistance. The self-sealing structure of MS-SOFCs is achieved by brazing technology. Plasma spraying is performed to prepare all functional layers of cells. The size of cells is 10 × 10 cm2. The coefficients of thermal expansion of relevant parts (i.e., porous metal support, interconnector and compound structure of both) and the electrical conductivity of brazing solder were measured. The microstructure of brazing area was observed in situ at 800 °C for 500 h, and the distribution of fuel gas in the interconnector was simulated. The performance of cells was characterized and found that the maximum power density can reach up to 716 mW cm−2 at 700 °C. Moreover, the long-term stability of the cell was investigated for about 500 h with 6 times of thermal cycling implemented during this period. The open circuit voltage and the maximum power density of the cell showed a good stability. [ABSTRACT FROM AUTHOR]

A novel self-sealing structure for metal-supported solid oxide fuel cells (MS-SOFCs) is designed by applying brazing technology between the metal support and interconnector to solve the sealing problem on the anode side of planar SOFCs. A high-reliability self-sealing effect is thus realized at the anode side of the MS-SOFC. Plasma spraying technology is used to prepare cell functional layers including the anode, cathode, and electrolyte. A single cell is assembled with a 50–60-μm plasma-sprayed Sc2O3-stabilized ZrO2 (ScSZ) electrolyte layer. The gas permeability of the self-sealed MS-SOFC without a cathode layer is 0.42 × 10−17 m2. The open-circuit voltage of the cell is ~ 1.1 V in the operating temperature range from 550 to 750 °C. The power density of the cell reaches 1109 mW cm−2 at 750 °C under standard atmosphere. In addition, the use of a fuel gas pressure that is 20 kPa higher than the cathodic gas pressure results in a significant increase in the power density to 1782 mW cm−2 at 750 °C. The novel cell structure and gas tightness of the ScSZ electrolyte prepared by plasma spraying indicates that it can meet the requirements of SOFC applications. [ABSTRACT FROM AUTHOR]