A kind of preparation method of solid oxide electrolytic cell high temperature fused carbonate air electrode
Technical field
The present invention relates to the preparation method of a kind of electrolytic cell anode.
Background technology
Electrolytic tank of solid oxide (Solid Oxide Electrolysis Cell, SOEC) be one can be by being converted into of electric energy
Learn the electrochemical appliance of energy, its principle is study more SOFC (Solid Oxide Fuel at present
Cell, SOFC) inverse process.The composition of SOEC is sandwich structure: the middle dielectric substrate for densification, both sides are many
The hydrogen electeode in hole and oxygen electrode.Electrolyte Main Function is to conduct oxonium ion in-between the electrodes, separate oxidation, reducing gas and
Intercept electronic conductance.Therefore, electrolyte needs have high ionic conductivity and insignificant electronic conductance, and in structure
Upper requirement is the finest and close.For the ease of diffusion and the transmission of gas, electrode is generally loose structure.
Similar with fuel cell, electrolytic tank of solid oxide can be divided into two classes according to the load difference of its electrolyte transport, i.e.
Oxonium ion electrolyzer and proton conductor electrolyzer.When applying certain voltage in the anode and cathode of oxygen ion conductor electrolyzer,
In the negative electrode of electrolyzer, carbon dioxide or water obtain electronics generation electrochemistry dissociation reaction, generate carbon monoxide and hydrogen respectively
Gas, generates oxonium ion simultaneously.Oxonium ion comes anode through fine and close electrolyzer thin film under the effect of electrochemical potential, loses
Oxygen it is converted into after electronics.Knowable to above electrochemical process, electrolyte needs fine and close airtight, to prevent anode and cathode
Gas mixes, it is to avoid exploding, anode and cathode is in addition to need to possessing oxonium ion, electronic conduction ability in addition, need to have certain
Porosity ensure gas diffusion in the electrodes.Owing to negative electrode is in reducing atmosphere, therefore cathode material needs to meet
Constitutionally stable requirement in high temperature reducing atmospheres, anode then needs to meet constitutionally stable in high temperature oxidative atmosphere wanting
Ask.Anode and cathode needs possess suitable electrochemical catalysis activity simultaneously, therefore, selects suitable anode and cathode electrode material to electricity
The performance of Xie Chi is most important.
In electrolytic process, the Stability Analysis of Structures of anode and cathode will be directly connected to the longtime running stability of electrolyzer.Substantial amounts of research table
Bright, the polarization resistance of electrolyzer Anodic directly affects the polarization resistance of the performance of electrolyzer, i.e. electrolyzer and is mainly determined by anode
Fixed, in addition the structural stability of anode is also the main factor of restriction electrolyzer long-time stability.Anode is with negative electrode not
With, anode happens is that the precipitation of gas, and when anodic overpotential increases, oxygen can form certain supersaturation at anode
Degree, higher degree of supersaturation can form certain pressure in the anode, and calculating the pressure showing to be formed at anode can reach
GPa level, the highest pressure can cause anode material structural damage, so that the polarization resistance of electrolytic cell anode increases
Add, and the microstructure of anode material can be destroyed, cause the thorough inefficacy of electrolyzer.In order to solve problem above, at present
More conventional method is the anode material or optimization anode construction developed and have more high electrochemical activity thus reduces electrode
The accumulation of middle pressure.But, when high overpotential large-current electric solution, electrode still can occur irreversible performance degradation.Mesh
The problem above that front electrolyzer exists does not has been resolved, and significantly constrains the commercial applications of electrolyzer.Accordingly, there exist
Such demand, i.e. develops and has constitutionally stable electrolytic cell anode material and realize the long-time steady operation of electrolyzer.
Summary of the invention
The invention aims to solve irreversible performance degradation that existing high-temperature electrolysis pond electrode exists and cannot be the most steady
The fixed problem run, and the preparation method of a kind of solid oxide electrolytic cell high temperature fused carbonate air electrode is proposed.
The preparation method of solid oxide electrolytic cell high temperature fused carbonate air electrode, realizes according to the following steps:
One, electrolyte is prepared: use the tape casting to prepare electrolyte;
Two, electrolytic thin-membrane is prepared: use high-temperature sintering process to prepare electrolytic thin-membrane in the electrolyte of step one;
Three, preparing porous cathode: porous cathode is prepared in the electrolytic thin-membrane side prepared in step 2, the voidage of negative electrode is
25%-50%, a diameter of 0.2-8 micron in hole, thickness is 20-80 micron;
Four, porous anode is prepared: use sol-gal process, solid reaction process, Glycine-nitrate combustion or combustion method of citric acid system
Standby ceramic powder, is subsequently adding pore creating material, obtains mixture after mixing;Use mixture electrolyte after preparing through step 3
The opposite side of thin film prepares porous anode, and the voidage of anode is 20%-60%, and a diameter of 0.1-8 micron in hole, thickness is
10-100 micron;
Five, in porous anode, introduce carbonate, then on porous cathode and porous anode, prepare remittance by silk screen print method
Fluid layer, then it is placed at 500 DEG C-900 DEG C sintering 0.1-6h, i.e. complete solid oxide electrolytic cell high temperature fused carbonate air
The preparation of electrode.
The carbonate added in the present invention will react under high temperature fused state, wherein carbonate decomposition be carbon dioxide with
Oxygen, simultaneously ejected electron;The carbon dioxide generated reacts generation carbonate at electrolytic surface and oxonium ion, so at anode
In can be formed one Guan Bi circulation;The circulation formed achieves the precipitation of oxygen indirectly, so can be substantially reduced oxygen at electrode table
The accumulation of surface pressure, makes electrolyzer take off the phenomenon that electrode delamination also will not occur at large-current electric, can significantly increase electrolysis
In the service life in pond, improve the stability of electrode, there is the ability of operation steady in a long-term;It is applicable to high-temperature electrolysis water, electrolysis
Carbon dioxide and water carbon dioxide common-battery solution equal energy source environment-protecting industrial field.
Accompanying drawing explanation
Fig. 1 is the schematic diagram of solid oxide electrolytic cell high temperature fused carbonate air electrode process in the present invention.
Detailed description of the invention
Technical solution of the present invention is not limited to the detailed description of the invention of act set forth below, also includes between each detailed description of the invention
Combination in any.
Detailed description of the invention one: the preparation side of present embodiment solid oxide electrolytic cell high temperature fused carbonate air electrode
Method, realizes according to the following steps:
One, electrolyte is prepared: use the tape casting to prepare electrolyte;
Two, electrolytic thin-membrane is prepared: use high-temperature sintering process to prepare electrolytic thin-membrane in the electrolyte of step one;
Three, preparing porous cathode: porous cathode is prepared in the electrolytic thin-membrane side prepared in step 2, the voidage of negative electrode is
25%-50%, a diameter of 0.2-8 micron in hole, thickness is 20-80 micron;
Four, porous anode is prepared: use sol-gal process, solid reaction process, Glycine-nitrate combustion or combustion method of citric acid system
Standby ceramic powder, is subsequently adding pore creating material, obtains mixture after mixing;Use mixture electrolyte after preparing through step 3
The opposite side of thin film prepares porous anode, and the voidage of anode is 20%-60%, and a diameter of 0.1-8 micron in hole, thickness is
10-100 micron;
Five, in porous anode, introduce carbonate, then on porous cathode and porous anode, prepare remittance by silk screen print method
Fluid layer, then it is placed at 500 DEG C-900 DEG C sintering 0.1-6h, i.e. complete solid oxide electrolytic cell high temperature fused carbonate air
The preparation of electrode.
Traditional oxygen electrode will occur half-reaction as is apparent from reaction 1 in there is oxygen precipitation process, and in reaction, oxonium ion loses
Electronics is converted into oxygen, and oxygen can be in the accumulation of electrode interface generation oxygen under electrode anode overpotential, i.e. oxygen is formed certain
Degree of supersaturation, the high oxygen tensions that accumulation is formed can destroy electrode structure, cause electrode performance to be decayed.
In present embodiment add carbonate under high temperature fused state by the reaction shown in 2 that reacts, wherein carbonate
It is decomposed into carbon dioxide and oxygen, simultaneously ejected electron;The carbon dioxide generated reacts generation carbon at electrolytic surface and oxonium ion
Hydrochlorate, as shown in Equation 3, can form the circulation of a Guan Bi, as shown in Figure 1 the most in the anode.The circulation formed is indirect
Achieve the precipitation of reaction oxygen shown in 1, so can be substantially reduced the oxygen accumulation at electrode surface pressure, improve the steady of electrode
Qualitative.
2O2-=O2+4e 1
Detailed description of the invention two: present embodiment is unlike detailed description of the invention one, and in step one, electrolyte is Y2O3
Stable ZrO2The CeO of electrolyte, Sm doping2The CeO of electrolyte, Gd doping2The ZrO that electrolyte, Sc are stable2
Electrolyte, the LaGaO that Sr and Mg is stable3One or more in electrolyte arbitrarily than mixture.Other step and ginseng
Number is identical with detailed description of the invention one.
Detailed description of the invention three: present embodiment unlike detailed description of the invention one, the burning of high-temperature sintering process in step 2
Junction temperature is 1200 DEG C-1600 DEG C, and sintering time is 1-10h.Other step and parameter are identical with detailed description of the invention one.
Detailed description of the invention four: present embodiment, unlike detailed description of the invention one, prepares porous cathode in step 3
Material be one or more in Ni/YSZ, Ni/SDC, Ni/ScSZ, Ni/LSGM arbitrarily than mixture.Other step
Rapid and parameter is identical with detailed description of the invention one.
Detailed description of the invention five: present embodiment, unlike detailed description of the invention one, prepares porous cathode in step 3
Method is silk screen print method, the tape casting or whirl coating.Other step and parameter are identical with detailed description of the invention one.
Detailed description of the invention six: present embodiment, unlike detailed description of the invention one, prepares porous cathode in step 3
Sintering temperature is 850 DEG C-1300 DEG C, and sintering time is 1-8h.Other step and parameter are identical with detailed description of the invention one.
Detailed description of the invention seven: present embodiment is unlike detailed description of the invention one, and in step 4, ceramic powder material is
The LaFeO of Sr and Co doping3, Ba and Co doping SrFeO3, La doping SrMnO3The LaFeO of material, Sr doping3
Material.Other step and parameter are identical with detailed description of the invention one.
Detailed description of the invention eight: present embodiment unlike detailed description of the invention one, in step 4 pore creating material be starch or
Graphite.Other step and parameter are identical with detailed description of the invention one.
Detailed description of the invention nine: present embodiment, unlike detailed description of the invention one, prepares porous anode in step 4
Method is silk screen print method, the tape casting or whirl coating.Other step and parameter are identical with detailed description of the invention one.
Detailed description of the invention ten: present embodiment, unlike detailed description of the invention one, prepares porous anode in step 4
Sintering temperature is 850 DEG C-1350 DEG C, and sintering time is 1-10h.Other step and parameter are identical with detailed description of the invention one.
Detailed description of the invention 11: present embodiment is unlike detailed description of the invention one, and in step 5, carbonate is
Li2CO3、K2CO3、Na2CO3In one or more arbitrarily than mixture.Other step and parameter be embodied as
Mode one is identical.
Detailed description of the invention 12: present embodiment is unlike detailed description of the invention one, in step 5 in porous anode
The method introducing carbonate is mixing oxides method or solution dipping method.Other step and parameter are identical with detailed description of the invention one.
Detailed description of the invention 13: present embodiment, unlike detailed description of the invention one, prepares the layer that confluxes in step 5
Material is conducting resinl, silver slurry, gold paste or platinum slurry.Other step and parameter are identical with detailed description of the invention one.
By following example checking beneficial effects of the present invention:
Embodiment 1
Using the tape casting to prepare a diameter of 100 millimeters, thickness is the YSZ (Y of 60 microns2O3Stable ZrO2) electrolysis
Matter, obtains the electrolyte sheet of densification for 4 hours through 1400 DEG C of high temperature sinterings.Silk screen print method is used to prepare cathode material
Ni/YSZ.Sol-gal process is used to be prepared for La0.8Sr0.2MnO3Ceramic powder, uses silk screen printing to be coated in YSZ table
Face, its diameter 6 millimeters, thickness is 30 microns.Above negative electrode, the sintering temperature of anode are respectively 1300 DEG C and 1150 DEG C.
The voidage of electrode is 35%.Solution dipping method is used to introduce K in above negative electrode2CO3And Na2CO3, the two mole
Ratio is 59:41.In negative electrode, weightening finish is 5%.Using silver to starch as the material preparing the layer that confluxes, sintering temperature is 750 DEG C.
Use Ceramabond552 as encapsulant.Electrolyzer at 800 DEG C, battery operation 1000 when decomposition voltage is 1.4V
Hour, decay is less than 3%, and the polarization resistance of electrolyzer is 0.60 Ω cm2。
Embodiment 2
Using the tape casting to prepare a diameter of 100 millimeters, thickness is the SDC (Sm of 60 microns0.1CeO2) electrolyte, pass through
1500 DEG C of high temperature sinterings obtain the electrolyte sheet of densification for 4 hours.Silk screen print method is used to prepare cathode material Ni/SDC.
Sol-gal process is used to be prepared for Ba0.6Sr0.4Co0.2Fe0.8O3Ceramic powder, uses silk screen printing to be coated in SDC surface,
Its diameter 6 millimeters, thickness is 30 microns.Above negative electrode, the sintering temperature of anode are respectively 1250 DEG C and 1100 DEG C.Electricity
The voidage of pole is 45%.Solution dipping method is used to introduce K in above negative electrode2CO3And Na2CO3, the mol ratio of the two
For 59:41.In negative electrode, weightening finish is 8%.Using silver to starch as the material preparing the layer that confluxes, sintering temperature is 750 DEG C.Adopt
With Ceramabond552 as encapsulant.Electrolyzer is at 800 DEG C, and when decomposition voltage is 1.2V, battery operation 1000 is little
Time, decay is less than 5%, and the polarization resistance of electrolyzer is 0.38 Ω cm2。
Embodiment 3
Using the tape casting to prepare a diameter of 100 millimeters, thickness is the ScSZ (Sc of 50 microns0.18Zr0.82O2) electrolyte,
The electrolyte sheet of densification within 6 hours, is obtained through 1550 DEG C of high temperature sinterings.Silk screen print method is used to prepare cathode material
Ni/ScSZ.Sol-gal process is used to be prepared for La0.6Sr0.4Co0.2Fe0.8O3Ceramic powder, uses silk screen printing to be coated in ScSZ
Surface, its diameter 6 millimeters, thickness is 45 microns.Above negative electrode, the sintering temperature of anode are respectively 1350 DEG C and 1000 DEG C.
The voidage of electrode is 35%.Solution dipping method is used to introduce K in above negative electrode2CO3And Li2CO3, the two mole
Ratio is 50:50.In negative electrode, weightening finish is 6%.Using silver to starch as the material preparing the layer that confluxes, sintering temperature is 750 DEG C.
Use Ceramabond552 as encapsulant.Electrolyzer at 850 DEG C, battery operation 1000 when decomposition voltage is 1.3V
Hour, decay is less than 6%, and the polarization resistance of electrolyzer is 0.8 Ω cm2。
Embodiment 4
Using the tape casting to prepare a diameter of 100 millimeters, thickness is the La of 300 microns0.9Sr0.1Ga0.8Mg0.2O3(LSGM)
Electrolyte, obtains the electrolyte sheet of densification for 10 hours through 1550 DEG C of high temperature sinterings.Silk screen print method is used to prepare negative electrode
Material Ni/LSGM.Sol-gal process is used to be prepared for La0.6Sr0.4Co0.2Fe0.8O3Ceramic powder, uses screen printing to brush
Applying on LSGM surface, its diameter 6 millimeters, thickness is 50 microns.Above negative electrode, the sintering temperature of anode are respectively
1300 DEG C and 1100 DEG C.The voidage of electrode is 35%.Solution dipping method is used to introduce Na in above negative electrode2CO3With
Li2CO3, the mol ratio of the two is 49:51.In negative electrode, weightening finish is 10%.Silver is used to starch as the material preparing the layer that confluxes,
Sintering temperature is 750 DEG C.Use Ceramabond552 as encapsulant.Electrolyzer is at 850 DEG C, and decomposition voltage is 1.4V
Time battery operation 800 hours, decay is less than 2%, and the polarization resistance of electrolyzer is 0.62 Ω cm2。