Half-cell of an electrolytic cell for an electrolyzer and method for producing a component for an electrolytic cell

Abstract

The invention concerns a half-cell (H1) of an electrolytic cell (EZ) for an electrolyzer (EY). The half-cell (H1) has an anode part-plate (AP) with perpendicular elevations (NP). Arranged on an upper side of the perpendicular elevations (NP) of the anode part-plate (AP) is an anode-transporting layer (AT). The half-cell (H1) has a membrane (MB), which is arranged on a side of the anode-transporting layer (AT) that is facing away from the elevations (NP) and which is permeable to specified charge carriers. In this case, the anode-transporting layer (AT) has a graduated pore structure, in which a respective diameter of the pores in the anode-transporting layer (AT) decreases in a direction perpendicularly towards the membrane (MB).

1 . A half-cell (H 1 ) of an electrolytic cell (EZ) for an electrolyzer (EY) comprising:
 an anode sub-plate (AP) of a first bipolar plate (BP 1 ), wherein the anode sub-plate (AP) comprises perpendicular elevations (NP);   a metallic anode transport layer (AT) arranged at a top surface of the elevations (NP) of the anode sub-plate (AP); and   a membrane (MB) arranged at the anode transport layer (AT) which is arranged at a side of the anode transport layer (AT) facing away from the elevations (NP) and is permeable to predetermined charge carriers,   wherein   the anode transport layer (AT) has a graduated pore structure where a respective diameter (D 1 , D 2 ) of the pores in the anode transport layer (AT) decreases in a direction perpendicularly facing the membrane (MB).   
     
     
         2 . The half-cell (H 1 ) as claimed in  claim 1 , wherein the pores of a first interface (G 1 ) of the anode transport layer which faces the elevations (NP) of the anode sub-plate (AT) have a first diameter (D 1 ) and the pores of a second interface (G 2 ) of the anode transport layer (AT) which faces the membrane (MB) have a second diameter (D 2 ), wherein a quotient of the second diameter (D 2 ) to the first diameter (D 1 ) is preferably within a first interval from 4 to 50. 
     
     
         3 . The half-cell (H 1 ) as claimed in  claim 2 , wherein for the pore structure a respective diameter of the pores between the first and the second interface (G 1 , G 2 ) of the anode transport layer (AT) is defined by a linear interpolation. 
     
     
         4 . The half-cell (H 1 ) as claimed in  claim 1 , wherein the respective diameter (D 1 , D 2 ) of the pores and/or a profile of the respective diameter (D 1 , D 2 ) of the pores within the anode transport layer (AT) is determined according to a predetermined pressure drop for an anode product, an electrical resistance caused by the anode transport layer (AT) and/or a predetermined gas pressure of the electrolytic cell (EZ). 
     
     
         5 . The half-cell (H 1 ) as claimed in  claim 1 , wherein an anode catalyst (AKA) is embedded in the anode transport layer (AT) and/or is arranged as a layer between the membrane (MB) and the anode transport layer (AT), wherein the anode catalyst comprises iridium, nickel and/or alloys of nickel, iron, oxygen, cobalt, ruthenium and/or mixtures of these substances. 
     
     
         6 . The half-cell (H 1 ) as claimed in  claim 5 , wherein the anode catalyst (AKA) is configured as a layer between the membrane (MB) and the anode transport layer (AT) and the layer has a layer thickness of 200 nm to 1 μm. 
     
     
         7 . The half-cell (H 1 ) as claimed in  claim 1 , wherein the anode transport layer (AT) includes a support structure (ST) having a first thickness (a 1 ) which is connected, contacted and/or interwoven with metallic fibers (FS) of a second thickness (a 2 ). 
     
     
         8 . The half-cell (H 1 ) as claimed in  claim 7 , wherein the first thickness (a 1 ) of the support structure (ST) and the second thickness (a 2 ) of the metallic fibers (FS) are determined according to a predetermined stiffness or a predetermined elasticity. 
     
     
         9 . The half-cell (H 1 ) as claimed in  claim 7 , wherein a quotient of the first thickness (a 1 ) and the second thickness (a 2 ) is between 2 and 100, in particular between 4 and 20, preferably between 5 and 10. 
     
     
         10 . The half-cell (H 1 ) as claimed in  claim 7 , wherein the metallic fibers (FS) comprise stainless steel, titanium and/or nickel. 
     
     
         11 . The half-cell (H 1 ) as claimed in  claim 7 , wherein the metallic fibers (FS) are coated with iridium, nickel and/or alloys of nickel, iron, oxygen, cobalt, ruthenium and/or mixed alloys of these substances. 
     
     
         12 . The half-cell (H 1 ) as claimed in  claim 7 , wherein the support structure (ST) is in a form of a grid and/or mesh and comprises stainless steel and/or coated carbon steel. 
     
     
         13 . The half-cell (H 1 ) as claimed in  claim 1 , wherein a number of elevations (NP) relative to a predetermined planar base area of the anode sub-plate (AT), a height, a width and/or a shape of the elevations (NP) is determined according to a predetermined pressure drop for an anode product, an electrical resistance caused by the anode sub-plate (AT) and/or a predetermined gas pressure of the electrolytic cell (EZ). 
     
     
         14 . The half-cell (H 1 ) as claimed in  claim 1 , wherein the anode sub-plate (AP) comprises and/or is coated with the following materials: stainless steel, titanium, spring steel, nitrogen, carbon, nickel, oxygen and/or mixtures thereof. 
     
     
         15 . The half-cell (H 1 ) as claimed in  claim 1 , wherein the anode transport layer (AT) has a thickness of 200 μm to 1000 μm and the elevations (NP) have a height perpendicular to the anode sub-plate (AT) of 1 to 5 mm. 
     
     
         16 . The half-cell (H 1 ) as claimed in  claim 1 , wherein the elevations (NP) each have a planar surface parallel to the anode sub-plate which is in direct contact with the anode transport layer (AT). 
     
     
         17 . The half-cell (H 1 ) as claimed in  claim 1 , wherein the anode sub-plate (AP), the anode transport layer (AT) and the membrane (MB) are secured in a cell frame (Z 1 , Z 2 ) and the cell frame (Z 1 , Z 2 ) comprises a seal (DT) which is especially configured such that the membrane (MB), the anode sub-plate (AP) and/or the anode transport layer (AT) are sealed. 
     
     
         18 . An electrolytic cell (EZ) having a first half-cell (H 1 ) as claimed in  claim 17 , further comprising a second half-cell (H 2 ) arranged at the membrane (MB), wherein the second half-cell comprises:
 a cathode sub-plate (KP) of a second bipolar plate (BP 2 ), wherein the cathode sub-plate (KP) comprises perpendicular elevations (NP);   a metallic cathode transport layer (KT) arranged at a top surface of the elevations (NP) of the cathode sub-plate (KT),   wherein the membrane (MB) is arranged at a side of the cathode transport layer (KT) facing away from the elevations (NP) and is permeable to further predetermined charge carriers, and   wherein   the cathode transport layer (KT) has a further graduated pore structure where a respective diameter (D 1 , D 2 ) of the pores in the cathode transport layer (KT) decreases in the direction perpendicularly facing the membrane (MB).   
     
     
         19 . The electrolytic cell (EZ) as claimed in  claim 18 , wherein the cathode sub-plate (KP) comprises nickel and/or is coated with nickel. 
     
     
         20 . The electrolytic cell (EZ) as claimed in  claim 18 , further comprising a cathode catalyst (KKA) embedded in the cathode transport layer (KT) and/or a cathode catalyst (KKA) arranged as a layer between the membrane (MB) and the cathode transport layer (KT), wherein the cathode comprises platinum, nickel, molybdenum, cobalt and/or mixtures thereof. 
     
     
         21 . A process for producing a half-cell (H 1 ) for an electrolytic cell (EZ) comprising the steps of:
 (S 1 ) stamping and/or embossing an anode sub-plate (AP) and a cathode sub-plate (KP) to form perpendicular elevations (NP);   (S 2 ) welding the anode sub-plate (AP) to the cathode sub-plate (KP) to form a bipolar plate (BP 1 , BP 2 );   (S 3 ) placing a respective transport layer (AT, KT) onto the elevations on both sides of the bipolar plate (BP 1 , BP 2 );   (S 4 ) pressing the respective transport layer (AT, KT) together with the bipolar plate (BP 1 , BP 2 ) using a respective contact pressure which is determined according to a predetermined flow resistance of a respective product of the electrolytic cell (EZ) and/or an electrical resistance of the respective transport layer (AT, KT);   (S 5 ) arranging a membrane (MB) at the respective transport layers (AT, KT); and   (S 6 ) sealing the membrane (MB) using a cell frame (Z 1 , Z 2 ) comprising a seal (DT) by clamping the seal (DT).