| 摘要 |
PURPOSE:To keep good airtightness in a return partitioning band for a long time by forming a sealant with fine electrolyte resistant powder and fluorine resin, and filling the sealant in a groove formed in a gas diffusion electrode, then applying heat treatment. CONSTITUTION:In an anode ribbed electrode 2, a groove 8 is formed in a partitioning band 6, and paste obtained by kneading fine electrolyte resistant powder, fine fluorine resin powder, and water is filled in the groove 8, then heat treatment is applied at 280-340 deg.C to sinter SiC fine particles. Phosphoric acid is impregnated into SiC fine particle sinter to form a sealant 11. Since electrolyte resistant fine particles serving as sealant mother material is bound with fluorine resin such as PTFE, decrease in the volume of the sealant caused by operation is reduced, and since phosphoric acid is impregnated in the voids of the sealant mother material, wet sealing is formed. Thereby, airtightness is remarkably increased. In addition, since phosphoric acid is stable at the operation temperature of a fuel cell, the evaporation of phosphoric acid during operation is prevented and good sealing is kept for a lengthy period of time. |
