Optimized processing of electrodes for SOFC and SOEC
Techniques for fabricating a solid oxide electrolyzer cell (SOEC) including sintering an electrolyte, printing a fuel-side electrode disposed on a fuel side of the electrolyte, printing an air-side electrode disposed on an air side of the electrolyte, first sintering a combination of the electrolyte, fuel-side electrode, and air-side electrode, printing a barrier layer an air side of the electrolyte, printing a functional layer on the barrier layer, printing a collector layer on the functional layer, and second sintering a combination of the electrolyte, fuel-side electrode, air-side electrode, barrier layer, functional layer, and collector layer.
1 . A method of fabricating a solid oxide electrolyzer cell (SOEC), the method comprising:
sintering an electrolyte comprising a stabilized zirconia material;
printing a fuel-side electrode comprising a cermet including a metal-containing phase and a ceramic phase on a fuel side of the electrolyte and printing a barrier layer comprising a samaria-doped ceria (SDC) material on an air side of the electrolyte to form a printed electrolyte;
sintering the printed electrolyte, at between 1190° C. and 1400° C. for a duration of between 0.5 hours and 4 hours, to sinter the printed fuel-side electrode including the cermet and densify the printed barrier layer during a same first sintering step;
printing a functional layer comprising a SDC material and an electrically conductive lanthanum strontium cobalt ferrite (LSCF) material on the densified barrier layer and printing a first collector layer on the functional layer after the first sintering step to form an electrolyzer cell; and
sintering the electrolyzer cell comprising the printed functional layer and the printed first collector layer, at between 800° C. and 1000° C. for a duration between 0.5 hours and 6 hours, during a same second sintering step after placing the electrolyzer cell into a SOEC stack.
2 . The method of fabricating a SOEC according to claim 1 , further comprising printing a second collector layer on the first collector layer.
3 . The method of fabricating a SOEC according to claim 1 , wherein the fuel-side electrode has two or more layers.
4 . The method of fabricating a SOEC according to claim 1 , further comprising printing an electrically conductive contact layer on the functional layer or on the fuel-side electrode.
5 . The method of fabricating a SOEC according to claim 1 , wherein the stabilized zirconia material comprises at least one of scandia-stabilized zirconia (SSZ), yttria-stabilized zirconia (YSZ), scandia-ceria-stabilized zirconia (SCSZ), scandia-ceria-yttria-stabilized zirconia (SCYSZ), and scandia-ceria-ytterbia-stabilized zirconia (SCYbSZ).
6 . The method of fabricating a SOEC according to claim 1 , further comprising densifying the barrier layer using cobalt nitrate Co(NO 3 ) 2 .
7 . A method of fabricating a solid oxide electrolyzer cell (SOEC), the method comprising:
printing a fuel-side electrode comprising a cermet including a metal-containing phase and a ceramic phase on a fuel side of an electrolyte and printing a barrier layer comprising a samaria-doped ceria (SDC) material on an air side of the electrolyte to form a printed electrolyte;
sintering the printed electrolyte, at between 1190° C. and 1400° C. for a duration of between 0.5 hours and 4 hours, to sinter the printed fuel-side electrode including the cermet and densify the printed barrier layer during a same first sintering step;
printing a functional layer comprising a SDC material and an electrically conductive lanthanum strontium cobalt ferrite (LSCF) material on the densified barrier layer and printing a first collector layer on the functional layer to form an electrolyzer cell;
stacking the electrolyzer cell and additional electrolyzer cells that include un-sintered first collector and functional layers between interconnects to form an SOEC stack; and
heating the SOEC stack, at between 800° C. and 1000° C. for a duration between 0.5 hours and 6 hours, to sinter the un-sintered first collector and functional layers of the electrolyzer cells during a same second sintering step.
8 . The method of fabricating a SOEC according to claim 7 , wherein the electrolyte comprises a stabilized zirconia including at least one of scandia-stabilized zirconia (SSZ), yttria-stabilized zirconia (YSZ), scandia-ceria-stabilized zirconia (SCSZ), scandia-ceria-yttria-stabilized zirconia (SCYSZ), and scandia-ceria-ytterbia-stabilized zirconia (SCYbSZ).
9 . The method of fabricating a SOEC according to claim 7 , further comprising densifying the barrier layer using cobalt nitrate Co(NO 3 ) 2 .
10 . A method of fabricating a solid oxide electrolyzer cell (SOEC), the method comprising:
printing a fuel-side electrode comprising a cermet including a metal-containing phase and a ceramic phase on a fuel side of an electrolyte and printing a barrier layer comprising a samaria-doped ceria (SDC) material on an air side of the electrolyte to form a printed electrolyte;
sintering the printed electrolyte, at between 1190° C. and 1400° C. for a duration of between 0 hours and 4 hours, to sinter the printed fuel-side electrode including the cermet and densify the printed barrier layer during a same first sintering step;
printing a functional layer comprising a samaria-doped ceria (SDC) material and an electrically conductive lanthanum strontium cobalt ferrite (LSCF) material on the densified barrier layer and printing a first collector layer on the functional layer to form an electrolyzer cell; and
sintering the electrolyzer cell comprising the printed functional layer and the printed first collector layer, at between 800° C. and 1000° C. for a duration between 0.5 hours and 6 hours, during a same second sintering step.
11 . The method of fabricating a SOEC according to claim 10 , wherein:
the electrolyte comprises a stabilized zirconia including at least one of scandia-stabilized zirconia (SSZ), yttria-stabilized zirconia (YSZ), scandia-ceria-stabilized zirconia (SCSZ), scandia-ceria-yttria-stabilized zirconia (SCYSZ), and scandia-ceria-ytterbia-stabilized zirconia (SCYbSZ).
12 . The method of fabricating a SOEC according to claim 10 , further comprising densifying the barrier layer using cobalt nitrate Co(NO 3 ) 2 .
13 . A solid oxide electrolyzer cell (SOEC) stack, comprising:
interconnects; and
a plurality of SOECs fabricated according to claim 1 and separated by the interconnects.
14 . The SOEC stack of claim 13 , wherein the SOEC stack is configured to alternately operate in a fuel cell mode and an electrolysis mode.