Component Constituting an HTE Electrolyser Interconnector or SOFC Fuel Cell Interconnector and Associated Production Processes

Abstract

The invention relates to a component ( 8 ) comprising a substrate made of chromia-former metal alloy ( 82 ), the basic element of which is iron (Fe) or nickel (Ni), wherein the substrate has two main planar faces. According to the invention:—one of the main planar faces is coated with a coating comprising a thick layer of ceramic ( 80 ), grooved to delimit channels ( 800 ) suitable for the distribution and/or collection of gases, such as H 2 O water vapour, H 2 or air, and/or—one of the main planar faces is coated with a thick metal layer ( 81 ), grooved to delimit channels ( 810 ) suitable for the distribution and/or collection of gases, such as H 2 O water vapour, H 2 , O 2 or draining gas. The invention also relates to the associated production processes.

1 . A component comprising a substrate made of metal alloy, of chromia-forming type, the base element of which is iron (Fe) or nickel (Ni), the substrate having two main flat faces, one of the main flat faces being coated with a coating comprising a thick ceramic layer, said thick ceramic layer being grooved, delimiting channels that are suitable for distributing and/or collecting gases, such as H 2 O steam, H 2 , air. 
     
     
         2 . A component comprising a substrate made of metal alloy, of chromia-forming type, the base element of which is iron (Fe) or nickel (Ni), the substrate having two main flat faces, one of the main flat faces being coated with a thick metallic layer, said thick metallic layer being grooved, delimiting channels that are suitable for distributing and/or collecting gases, such as H 2 O steam, H 2 ; O 2 , draining gas. 
     
     
         3 . The component as claimed in  claim 1  in combination with  claim 2 , one of the main flat faces being coated with a coating comprising a thick ceramic layer and the other of the main flat faces being coated with a thick metallic layer, each of the thick layers being grooved, delimiting channels that are suitable for distributing and/or collecting gases, such as H 2 O steam, draining gas, air, O 2 , H 2 . 
     
     
         4 . The component as claimed in  claim 1 , the material of the thick ceramic layer being chosen from a lanthanum manganite of formula La 1-x Sr x MO 3  with M (transition metals)=Ni, Fe, Co, Mn, Cr, alone or as a mixture, or materials of lamellar structure such as lanthanide nickelates of formula Ln 2 NiO 4  (Ln=La, Nd, Pr), or another electrically conductive perovskite oxide. 
     
     
         5 . The component as claimed in  claim 2 , the material of the thick metallic layer being chosen from nickel (Ni) and alloys thereof and also all the chromia-forming alloys whose base element is iron (Fe). 
     
     
         6 . The component as claimed in  claim 1 , the thickness of the ceramic layer being between 60 and 500 μm. 
     
     
         7 . The component as claimed in  claim 2 , the thickness of the metallic layer being between 60 and 500 μm. 
     
     
         8 . The component as claimed in  claim 1  or  claim 2 , the chromia-forming metal alloy of the substrate being chosen from ferritic (Fe—Cr), austenitic (Ni—Fe—Cr) stainless-steel alloys or superalloys based on nickel forming at the surface a layer of chromium oxide Cr 2 O 3 , known as the chromia layer. 
     
     
         9 . The component as claimed in  claim 1  or  claim 2 , the substrate consisting of at least one thin sheet. 
     
     
         10 . The component as claimed in  claim 9 , the thickness of a thin sheet being between 0.1 and 1 mm. 
     
     
         11 . The component as claimed in  claim 1  or  claim 2 , the substrate consisting of a single plate with flat main faces. 
     
     
         12 . The component as claimed in  claim 11 , the thickness of the plate being between 1 and 10 mm. 
     
     
         13 . The component as claimed in  claim 3 , consisting of an interconnector of a high-temperature electrolysis (HTE) reactor comprising a stack of elementary electrolysis cells each formed from a cathode, an anode and an electrolyte intercalated between the cathode and the anode, the thick grooved ceramic layer being in contact with the anode of one of the two adjacent elementary cells, the thick grooved metallic layer being in contact with the cathode of the other of the two adjacent elementary cells. 
     
     
         14 . The component as claimed in  claim 3 , constituting an interconnector of a fuel cell (SOFC) comprising a stack of elementary cells each formed from a cathode, an anode and an electrolyte intercalated between the cathode and the anode, the thick grooved ceramic layer being in contact with the cathode of one of two adjacent elementary cells, the thick grooved metallic layer being in contact with the anode of the other of the two adjacent elementary cells. 
     
     
         15 . The component as claimed in  claim 1  or  claim 2 , the width of the channels being between 0.15 and 5 mm. 
     
     
         16 . The component as claimed in  claim 1  or  claim 2 , the depth of the channels being between 0.1 and 0.5 mm. 
     
     
         17 . A process for preparing a component intended to constitute an interconnector for a fuel cell (SOFC) or a high-temperature electrolyzer (HTE), comprising the following steps:
 a/ preparing a substrate made of metal alloy, of chromia-forming type, the base element of which is iron (Fe) or nickel (Ni), the substrate having two main flat faces,   b1/ coating one of the flat faces of the substrate with a thick ceramic layer;   c1/ grooving the thick ceramic layer so as to delimit channels that are suitable for distributing and/or collecting gases, such as H 2 O steam, H 2 ; air.   
     
     
         18 . A process for preparing a component, intended to constitute an interconnector for a fuel cell (SOFC) or a high-temperature electrolyzer (HTE), comprising the following steps:
 a/ preparation of a substrate made of metal alloy, of chromia-forming type, the base element of which is iron (Fe) or nickel (Ni), the substrate having two main flat faces,   b2/ coating one of the flat faces of the substrate with a thick metallic layer;   c2/ grooving the thick metallic layer so as to delimit channels that are suitable for distributing and/or collecting gases, such as H 2 O steam, H 2 ; air.   
     
     
         19 . The process as claimed in  claim 17  or  claim 18 , steps b1/ and c1/ being performed on one flat face of the substrate, steps b2/ and c2/ being performed on the other flat face of the substrate. 
     
     
         20 . The process as claimed in  claim 17  or  claim 18 , in which, prior to step b1/ and/or step b2/, the thick ceramic or metallic layer is obtained by pouring in a strip, step b1/ and/or b2/ consisting of hot-bonding or hot-pressing or chemical bonding of the strip to one or other of the faces of the substrate. 
     
     
         21 . The process as claimed in  claim 20 , step b1/ consisting of hot-pressing or hot-bonding of the crude ceramic strip at a temperature of between 60 and 130° C. 
     
     
         22 . The process as claimed in  claim 17  or  claim 18 , step b1/ and/or b2/ consisting of screen printing in thick layers of a ceramic or metallic paste onto one or other of the faces of the substrate. 
     
     
         23 . The process as claimed in  claim 20 , step c1/ being performed by calendaring the crude ceramic strip obtained by pouring between two rolls heated to the softening point of the polymers of the ceramic strip, at least one of the two rolls comprising ribs corresponding to the channels to be delimited, step b1/ being performed after step c1/. 
     
     
         24 . The process as claimed in  claim 17  or  claim 18 , step c1/ and/or c2/ being performed by laser ablation once step b1/ and/or b2/, respectively, has been completed. 
     
     
         25 . The process as claimed in  claim 24 , step c1/ and/or c2/ being performed using a CO 2  laser. 
     
     
         26 . The process as claimed in  claim 24 , step c1/ and/or c2/ being completed after several passes of the laser over the thick layer.