Electrochemical reaction unit and fuel cell stack

Abstract

Electrochemical reaction unit comprising: a unit cell (110) including an electrolyte layer (112) containing a solid oxide, and a cathode (114) and an anode (116) facing each other in a first direction with the electrolyte layer (112) between them, a current collector (134) arranged on a cathode side of the unit cell (110), and an electrically conductive, porous bonding layer (138) bonding the current collector (134) and the cathode (114) together, wherein in at least one cross-section of the bonding layer (138) parallel to the first direction a bonding region (400) arranged between the current collector (134) and the cathode (114) contains: a block section (410) in which at least one pore is a pore having a pore size of 20% or more of the thickness of the bonding region (400) in the first direction. the first direction is fulfilled,at least on the side of the bonding area of ​​a cross-sectional surface between the cathode (114) and the bonding area (400) or on the side of the bonding area of ​​a cross-sectional surface between the current collector (134) and the bonding area (400), wherein the block section (410) extends inwards from one of the opposite ends in a second direction orthogonal to the first direction of the bonding area (400), which is closer to the pore fulfilling the pore requirement, and reaches and encompasses the pore fulfilling the pore requirement, and an electrical conductivity assurance section (420) which is arranged towards the other end of the bonding area (400) with respect to the block section (410) and which does not contain any pores fulfilling the pore requirement and has a smaller average diameter of the pores than the block section (410).

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