Abstract: Planar solid oxide fuel cell (SOFC) is a technology which converts chemical energy into electrical energy directly. Its advantages are high efficiency in energy utilization, compact structure and low pollution to environment, etc, which makes it to be the best replacement of fossil energy. In SOFC stack, sealing technology must be used in order to prevent the leakage. But the high working temperature puts forwards a high requirement for the sealing. It needs good chemical and thermal stabilities, tightness and insulation performance. Therefore, the sealing technology is always the hinder of commercial use for SOFC. Bonded compliant seal (BCS) design is a newly developed sealing method for planar SOFC. It uses a thin foil to connect the cell and window frame, and it has a lot advantages including high strength, good sealing performance and absorbing thermal stresses, etc., which has a broad potential application in the future. This paper introduces its principle, characteristics and application. The research progress is reviewed based on material, brazing technology and residual stress. The problems to be solved are pointed out and the development trend is forecasted.

Key words: Bonded compliant seal, Brazing technology, Residual stress, Solid oxide fuel cell