Plant and method for producing a half-cell for solid state fuel cells

Abstract

A method (100) for producing a half-cell (1), in particular formed by a double ceramic layer consisting of an electrode (4) and an electrolyte (5) coupled to each other, for a solid state fuel cell, comprises a process (200) for producing a green electrode body (2); a process (300) for producing a green electrolyte body (3); a coupling step (400), in which the green electrode body (2) and the green electrolyte body (3) are coupled together; and a sintering step (500), following the coupling step (400), in which the green electrode body (2) and the green electrolyte body (3) coupled together are sintered so as to make the half-cell (1) formed by the coupled electrode (4) and electrolyte (5).

Description

"Plant and method for producing a half-cell for solid state fuel cells"

[0001] Field of the invention

[0002] The present invention relates to a plant and method for continuously producing a half-cell, in particular an electrode and an electrolyte forming a double ceramic layer, for solid state fuel cells, also known as Solid Oxide Cells (SOCs).

[0003] Background art

[0004] In the 21 st century, among the many challenges facing humanity, the issue of sustainable energy supply emerges as an undeniable priority. This challenge is further accentuated by the growing world population and the resulting increases in energy consumption. The energy revolution has already begun. We are witnessing a gradual transition from the unconditional use of fossil fuels to one where renewable resources increasingly gain a slice of the market, thus revolutionizing the old paradigms. Therefore, it is necessary to find non-polluting technological solutions which are capable of integrating into a new energy system based on the use of effective energy carriers produced and used within a closed cycle of carbon dioxide emission and reuse.

[0005] Solid state fuel cells are electrochemical devices which can convert chemical energy into electricity and heat or reversibly store excess electrical energy and heat, producing chemical fuels.

[0006] By harnessing electricity from renewable sources, SOCs produce high- efficiency energy and generate clean chemicals such as green hydrogen, ammonia or synthetic gas. Hydrogen can be used as a fuel for hydrogen vehicles or for producing steel, ammonia for producing fertilizers, and synthetic gas for generating energy.

[0007] Moreover, the chemical reaction for producing synthetic gases employs CO2, thus contributing to the absorption of carbon dioxide. Alternatively, by feeding the cell with methane or hydrogen, electricity is obtained as a result. When hydrogen is used as a fuel, the only by-product is water, while carbon dioxide is produced using methane, avoiding however the formation of NOx and SOx.

[0008] This technology has several positive features, including reversibility, high efficiency, low cost and fuel flexibility. Moreover, SOCs are made from widely available ceramic oxide materials, such as zirconium oxide and nickel oxide.

[0009] Nevertheless, SOCs still have several critical issues which have prevented the mass dissemination thereof. In particular, the production cost is one of the main obstacles to overcome.

[0010] The half-cell of an SOC is formed by an electrode and an electrolyte, and theelectrode represents one of the largest sources of cost of the cell. In fact, in terms of thickness, it represents more than 90% of the total thickness. The electrode has a thickness between 100-500 |im before being sintered. The electrolyte has a thickness between 3-20 |im before being sintered.

[0011] In the prior art, both layers can be produced individually by tape casting and then rolled, or produced by electrode tape casting and subsequent co-casting of the electrolyte, or produced by electrode tape casting and subsequent screen printing of the electrolyte.

[0012] The use of the tape casting technique requires the preparation of a suspension with a viscosity between 100 and 900 cps, which requires a preparation time between 5- 48 h depending on whether a continuous or static flow mill is used. The powders are mixed with binders and additives. They are then ground for several hours to achieve suspension homogenization. Some preparations also include a subsequent addition of binders and additives after the grinding process. The suspension must also be filtered and degassed.

[0013] The tape casting technique includes withdrawing the suspension from a pressure vessel and pouring it into a tank, also called Dr. Blade, adapted to pass an adequate amount of suspension below a blade, finally depositing it on a sliding support. The layer, thus cast, will then be subjected to a drying step. The typical speeds of this process for solid oxide cells are between 0.2 and 2 meters per minute depending on the length of the tape casting and the thickness of the layer to be cast. With the same length of tape casting, the thickness significantly affects the process speed. The greater the thickness of the layer to be cast, the lower the casting speed.

[0014] The tape casting process is a casting process which cannot be stopped on demand. In fact, in the event of an interruption of the process, part of the suspension already present inside the calm Dr. Blade tank, the suspension already present inside the tubes connecting the suspension container and part of the suspension already cast, would be lost.

[0015] Furthermore, the tape casting technique remains very sensitive to variations in the input raw materials (such as viscosity and dispersion quality) and external variables such as air temperature, humidity, the quality of the plastic support used for casting, and the non-stick coating thereof.

[0016] The addition of the second layer, the electrolyte, can occur by means of another deposition with tape casting above the layer already previously cast and dried or through a single deposition of the new layer with a subsequent rolling to join the twolayers cast individually. In the prior art with respect to the first case, the thin layer is cast first and the thicker layer is cast above the latter. Co-casting can occur continuously or in batches.

[0017] In the case of co-casting, special attention is required in the selection of the binders and additives used to create the suspensions to be cast. In fact, for both the first and the second layer, the same family of binders must be used so as not to encounter delamination or defects such as cracks, air bubbles, surface roughness and various deformations, during the drying step of the second layer on the first. Given the substantial difference in the thicknesses of the two layers forming the ceramic half-cell, it may be appropriate to use different types of binders and additives in order to speed up the drying time of the layer often maintaining the porosity thereof and to be able to obtain a thin green layer, i.e., before sintering, with an already high density.

[0018] Tape casting is very subject to the formation of defects due to contamination of the suspension before and during casting. It is therefore required to operate in controlled environments where it is essential to maintain strict standards of air cleanliness and purity, with cleanliness levels of at least ISO class 5.

[0019] The production waste of the half-cells by a traditional method is between 10 and 30%, considering the material loss which occurs during all the steps of the preparation which go from the creation of the suspensions up to the creation of the green cell by tape casting, also considering the cutting waste to obtain the cell of desired dimensions. Tape casting machines also have very high costs.

[0020] The need is therefore felt for an improved plant and method for producing halfcells for solid state fuel cells with respect to the prior art.

[0021] Solution

[0022] It is the object of the present invention to provide a plant and method for producing a half-cell for a solid state fuel cell, which allows achieving continuous production of the half-cell.

[0023] It is a further particular object of the present invention to provide a plant and method for producing a half-cell for a solid state fuel cell, which is scalable, cost-effective and continuous.

[0024] It is a further particular object of the present invention to provide a plant and method for producing a half-cell for a solid state fuel cell, which allows reducing or eliminating waste or scrap of the slip used to produce the half-cell, and which in particular allows interruptions of the production process which do not generate slip losses or waste.

[0025] It is a further particular object of the present invention to provide a plant andmethod for producing a half-cell for a solid state fuel cell, which is less subject to defects due to contamination and which allows the use of any family of binder and additive regardless of whether it is used for preparing the slip and / or the suspension for the thin layer without necessarily being part of the same family.

[0026] It is a further particular object of the present invention to provide a plant and method for producing a half-cell for a solid state fuel cell, which allows speeding up the production of the half-cell.

[0027] It is a further particular object of the present invention to provide a plant and method for producing a half-cell for a solid state fuel cell, which reduces the overall times and costs of producing the half-cell.

[0028] These and other objects are achieved by a plant and a method for producing a half-cell for a solid state fuel cell, according to the independent claims.

[0029] The dependent claims relate to preferred and advantageous embodiments of the present invention.

[0030] Figures

[0031] In order to better understand the invention and appreciate the advantages thereof, some non-limiting exemplary embodiments thereof will be described below with reference to the accompanying drawings, in which:

[0032] - Figure 1 is a diagrammatic depiction of a plant for producing a half-cell for a solid state fuel cell, according to an embodiment of the invention;

[0033] - Figure 2 is a diagrammatic depiction of a plant for producing a half-cell for a solid state fuel cell, according to a further embodiment of the invention;

[0034] - Figure 3 depicts a microscope image showing the porous layer of a green electrode body produced by the plant and method for producing a half-cell for a solid state fuel cell, according to an embodiment of the invention;

[0035] - Figure 4 depicts a microscope image showing the layer of a thin green electrolyte body produced by the plant and method for producing a half-cell for a solid state fuel cell, according to an embodiment of the invention.

[0036] Description of some preferred embodiments

[0037] Method 100

[0038] A method 100 for producing a half-cell 1 , in particular formed by a double ceramic layer consisting of an electrode 4 and an electrolyte 5 coupled together, for a solid state fuel cell, comprises the following steps:

[0039] - a process 200 for producing a green electrode body 2,

[0040] - a process 300 for producing a green electrolyte body 3.

[0041] The process 200 for producing the green electrode body 2 is carried out before or after or simultaneously with the process 300 for producing the green electrolyte body 3.

[0042] The method 100 further comprises:

[0043] - a coupling step 400, in which the green electrode body 2 and the green electrolyte body 3 are coupled together,

[0044] - a sintering step 500, following the coupling step 400, in which the green electrode body 2 and the green electrolyte body 3 coupled together are sintered so as to make the half-cell 1 formed by the coupled electrode 4 and electrolyte 5.

[0045] Specifically, in the sintering step 500 the green electrode body 2 is sintered so as to form the electrode 4 and the green electrolyte body 3 is sintered so as to form the electrolyte 5.

[0046] The method 200 for producing the green electrode body 2 comprises the following manufacturing steps:

[0047] - a step 210 of producing a viscous ceramic composition, also called slip 20;

[0048] - a step 220 of mixing the slip 20, so as to form a slurry 21 ;

[0049] - a step 230 of extruding the slurry 21 , so as to form an extruded slurry 22;

[0050] - a step 240 of calendering the extruded slurry 22, so as to form the green electrode body 2.

[0051] The process 300 for producing the green electrolyte body 3 comprises the following manufacturing steps:

[0052] - a step 310 of producing an electrolyte suspension 30;

[0053] - a step 320 of depositing the electrolyte suspension 30, by means of slot die, preferably by means of curtain slot die, so as to make a film of green electrolyte body 3;

[0054] - optionally, a drying step 330, in which the film of green electrolyte body 3 is heated, in particular dried.

[0055] Advantageously, a method 100 thus configured for producing a half-cell for a solid state fuel cell allows continuous production of the half-cell, is scalable and has low costs as compared to the prior art.

[0056] With further advantage, a method 100 thus configured allows reducing or eliminating losses and waste of the slip, since it does not include or require a tape casting step, and also allows interruptions of the production process which do not generate slip losses or waste.

[0057] With further advantage, a method 100 thus configured allows speeding up the production of a half-cell, since it allows producing half-cells at speeds of 5-10 m / min, with layers which can have widths from 100 mm to 3000 mm.

[0058] With further advantage, a method 100 thus configured allows calendering layers, i.e., electrode, between 100 pm and 500 pm, by means of a single calendering or by means of a sequence of calendering rollers.

[0059] According to an embodiment, the slip 20 is produced, in step 210, by means of the following components, preferably exclusively by means of the following components:

[0060] - nickel oxide (NiO);

[0061] - zirconium oxide (YSZ);

[0062] - pore formers;

[0063] - a binder;

[0064] - a plasticizer.

[0065] The aforesaid elements are combined with each other so as to form the slip 20.

[0066] According to an embodiment, the components of the slip 20 have the following percentages by weight:

[0067] - nickel oxide (NiO): 20-40%;

[0068] - zirconium oxide (YSZ): 20-40%;

[0069] - pore former: 1 -15%;

[0070] - a binder: 30-50%;

[0071] - a plasticizer: 1 -15%.

[0072] According to an embodiment, the nickel oxide and the zirconium oxide are in powder form.

[0073] According to an embodiment, the nickel oxide powder and the zirconium oxide powder both have a Particle Size Distribution (PSD) less than 0.5 pm.

[0074] According to an embodiment, the binder and the plasticizer both consist of polyacrylates, but can also comprise ethylene copolymers, maleic acid copolymers, styrene copolymers, acrylate or methacrylate copolymers, vinyl acetate copolymers, polyvinyl butyral resins, vinyl acetal resins, vinyl resins, vinyl alcohol resins, waxes and cellulose such as ethyl cellulose. These binders can be used alone or in combination with each other.

[0075] According to an embodiment, the binder is a binder based on partially water-soluble acrylic polymers, where the binder has a solid load between 30% and 40%.

[0076] According to an embodiment, the binder is an acrylic binder and / or a vinyl and / or a cellulose based on water or based on solvent. According to an embodiment, the water-based binders are formed from partially or completely water-soluble polymers or can be polymer emulsions.

[0077] According to an embodiment, the plasticizer is a plasticizing agent consisting of 100% amine-containing polymer.

[0078] According to an embodiment, the pore former is one or a combination of the following: starch, cellulose, acrylic polymers, carbon black.

[0079] According to an embodiment, the step of 220 of mixing the slip 20 includes mixing the aforesaid components by means of a wet mixer 62, to form the slurry 21 .

[0080] According to an embodiment, the components forming the slip 20 are mixed in the wet mixer 62 for a duration of time between 10 min and 30 min, preferably between 15 min and 25 min, preferably for about 20 min.

[0081] According to an embodiment, upon mixing, the step 220 of mixing the slip 20 can include degassing the slurry 21 , so as to form a degassed slurry 21 .

[0082] Advantageously, the preparation of the slip 20 and the slurry 21 thus configured does not require ball-milling. Therefore, the method allows preventing the loss of material and has reduced times as compared to the prior art.

[0083] According to an embodiment, following the degassing, the step 230 is carried out in which the slurry 21 is extruded, so as to make the extruded slurry 22.

[0084] According to an embodiment, the extruded slurry 22 has a thickness less than 2 mm.

[0085] The calendering step 240 is carried out following the extrusion step 230 of the extruded slurry 22.

[0086] According to an embodiment, the calendering step 240 is carried out so as to make a green electrode body 2 of thickness between 50 pm and 10,000 pm but preferably less than or equal to about 350 pm ± 10 pm.

[0087] According to an embodiment, the calendering step 240 is carried out so as to make a green electrode body 2 of thickness of about 100 pm ± 10 pm.

[0088] According to an embodiment, the calendering step 240 is carried out by means of at least one pair of rollers 80, one opposite the other with respect to the extruded slurry 22 to be extruded so as to form the green electrode body 2.

[0089] According to an embodiment, the calendering step 240 is carried out by asingle pair of rollers 80.

[0090] Advantageously, such a configuration allows reducing the production times of the half-cell 1 as well as reducing the overall dimensions of the production plant 1000 of the half-cell 1 .

[0091] According to an embodiment, during the calendering step 240 at least one of the rollers 80 of the at least one pair of rollers 80, preferably each roller of the at least one pair of rollers 80, is heated.

[0092] According to an embodiment, the one or more rollers 80 are heated to a temperature between 40°C and 50°C.

[0093] According to an embodiment, during the calendering step 240 the rollers 80 are rotated at a tangential speed between 5 m / min and 10 m / min, or of about 5 m / min. Therefore, the extruded slurry 22 subjected to calendering so as to form the green electrode body 2 advances between the at least one pair of opposite rollers 80 at a speed between 5 m / min and 10 m / min, preferably of about 5 m / min.

[0094] With further advantage, the green electrode body 2 thus formed does not need a drying step, as instead required in the prior art.

[0095] First embodiment of the coupling step 400

[0096] According to an embodiment (Fig. 1 ), the drying step 330 is carried out following the coupling step 400 between the film of green electrolyte body 3 and the green electrode body 2.

[0097] In accordance with this embodiment, the step 320 of depositing the electrolyte suspension 30, by means of slot die, includes depositing the electrolyte suspension 30 directly on the green electrode body 2.

[0098] Thereby, by means of slot die, the film of green electrolyte body 3 is continuously deposited on the green electrode body 2 produced following the calendering step 240. Thereby, the coupling step 400 occurs.

[0099] In accordance with this embodiment, following the coupling step 400 between the green electrode body 2 and the green electrolyte body 3 deposited on the green electrode body 2 by means of slot die, the drying step 330 of the green electrolyte body 3 is carried out. Thereby, the green electrolyte body 3 is dried.

[0100] Second embodiment of the coupling step 400

[0101] According to an embodiment (Fig. 2), the drying step 330 is carried out before the coupling step 400 between the green electrolyte body 3 and the green electrode body 2.

[0102] In accordance with this embodiment, the step 320 of depositing the electrolyte suspension 30, by means of slot die, preferably by means of curtain slot die, includes depositing the electrolyte suspension 30 on a sliding support 32, preferably a flat polymer support.

[0103] Thereby, by means of slot die, the film of green electrolyte body 3 is continuously deposited on the sliding support 32.

[0104] In accordance with this embodiment, following the deposition of the film of green electrolyte body 3 on the sliding support 32 by means of slot die, the drying step 330 of the green electrolyte body 3 is carried out.

[0105] Such a drying step 330 is carried out before the coupling step 400 between the green electrolyte body 3 and the green electrode body 2.

[0106] In accordance with this embodiment, the coupling step 400 between the green electrolyte body 3 and the green electrode body 2 provides for the green electrolyte body 3 and the green electrode body 2 both being conveyed in the direction of a rolling station 5000.

[0107] The rolling station 5000 comprises at least one pair of opposite rolling rollers.

[0108] The green electrolyte body 3 and the green electrode body 2 conveyed towards the rolling station 5000 are positioned stacked, i.e., facing each other.

[0109] The coupling between the green electrode body 2 and the green electrolyte body 3 is carried out by means of the rolling rollers of the rolling station 5000.

[0110] Plant 1000

[0111] According to a further aspect of the invention, a plant 1000 for producing a half-cell 1 , in particular formed by a double ceramic layer consisting of an electrode 4 and an electrolyte 5 coupled together, for a solid state fuel cell comprises:

[0112] - an electrode station 2000, in which the production of a green electrode body 2 is carried out,

[0113] - an electrolyte station 3000, in which the production of a green electrolyte body 3 is carried out,

[0114] - a coupling station 4000, in which the coupling between the green electrode body 2 and the green electrolyte body 3 is carried out,

[0115] - a sintering station 5000, in which the green electrode body 2 and the green electrolyte body 3 coupled together are sintered so as to make the half-cell 1 formed by the coupled electrode 4 and electrolyte 5.

[0116] The electrode station 2000 comprises a slip station 7000, for producing, mixingand extruding a slip 20, so as to make an extruded slurry 22.

[0117] The electrode station 2000 further comprises a calendering station 8000. The calendering station 8000 is configured to calender the slip 20, in particular to calender of the extruded slurry 22, so as to form the green electrode body 2.

[0118] The electrolyte station 3000 comprises a casting station 6000, for producing an electrolyte suspension 30 and for depositing the electrolyte suspension 30, by means of slot die, preferably by means of curtain slot die, so as to make a film of green electrolyte body 3.

[0119] Optionally, the electrolyte station 3000 further comprises a drying station 9000, for drying the film of green electrolyte body 3.

[0120] Advantageously, a plant 1000 thus configured allows continuous production, and is scalable and has low costs as compared to the prior art.

[0121] With further advantage, a method 100 thus configured allows reducing or eliminating losses and waste of the slip, since it does not include or require a tape casting step.

[0122] With further advantage, a method 100 thus configured allows speeding up the production of a half-cell, since it allows producing half-cells at speeds of 5-10 m / min, with layers which can have widths from 100 mm to 3000 mm.

[0123] With further advantage, a method 100 thus configured allows calendering layers, i.e., electrode, between 100 pm and 10,000 pm, by means of a single calendering or by means of a sequence of calendering rollers, preferably less than or equal to about 350 pm ± 10 pm.

[0124] According to an embodiment, the slip station 7000 comprises a wet mixer 62.

[0125] The components forming the slip 20 can be mixed by means of the wet mixer 62.

[0126] According to an embodiment, the slip station 7000 comprises a hopper 61 fluidly connected to the wet mixer 62.

[0127] The components forming the slip 20 can be loaded inside the hopper 61 and mixed by means of the wet mixer 62.

[0128] According to an embodiment, the slip station 7000 comprises an extruder 63, configured to extrude the extruded slurry 22.

[0129] The extruder 63 is fluidly connected to the wet mixer 62, so as to extrude the extruded slurry 22 resulting from mixing the slip 20 in the wet mixer 62.

[0130] According to an embodiment, the slip station 7000 comprises a degasser,configured to degas of the slip 20, so as to form the slurry 21 .

[0131] According to an embodiment, the calendering station 8000 comprises at least one pair of opposite rollers.

[0132] According to an embodiment, at least one of the two rollers of the pair of opposite rollers is heated.

[0133] The calendering station 8000 is positioned downstream of the electrode station 2000.

[0134] The calendering station 8000 is positioned upstream of the coupling station 4000.

[0135] According to an embodiment, the drying station 9000 is positioned downstream of the coupling station 4000 (Fig. 1 ).

[0136] In accordance with this embodiment, the electrode station 3000 is configured to deposit the electrolyte suspension 30 directly on the green electrode body 2.

[0137] According to an embodiment, the drying station 9000 is positioned upstream of the coupling station 4000 (Fig. 2).

[0138] In accordance with this embodiment, the electrode station 3000 is configured to deposit the electrolyte suspension 30 on a sliding support 32, preferably a flat polymer support. Thereby, by means of slot die, the film of green electrolyte body 3 is continuously deposited on the sliding support 32.

[0139] In accordance with this embodiment, following the deposition of the film of green electrolyte body 3 on the sliding support 32 by means of slot die, the drying step 330 of the green electrolyte body 3 is carried out.

[0140] Thereby, the film of green electrolyte body 3, deposited on the sliding support 32, is heated.

[0141] Such a drying step 330 is carried out before the coupling step 400 between green electrolyte body 3 and green electrode body 2.

[0142] According to an embodiment, the plant 1000 comprises a rolling station 5000.

[0143] The rolling station 5000 comprises at least one pair of opposite rolling rollers.

[0144] The rolling station 5000 is configured to roll and couple the green electrolyte body 3 and the green electrode body 2 stacked and conveyed to the rolling station 5000.

[0145] "Upstream" and "downstream" refer to the advancement direction of the components forming the electrode 2, the electrolyte 3, and in general the half-cell 1 .

[0146] Obviously, those skilled in the art will be able to make changes or adaptations to the present invention, without however departing from the scope of the followingclaims.REFERENCE NUMERALS1 . Half-cell2. Green electrode body3. Green electrolyte body4. Electrode5. Electrolyte20. Slip21. Slurry22. Extruded slurry30. Electrolyte suspension32. Sliding support61 . Hopper62. Wet mixer63. Extruder80. Rollers100. Method200. Process for producing the electrode210. Slip production step220. Slip mixing step230. Extrusion step240. Calendering step300. Process for producing the electrolyte310. Suspension production step320. Suspension deposition step330. Drying step400. Coupling step500. Sintering step1000. Plant2000. Electrode station3000. Electrolyte station4000. Coupling station5000. Rolling station5500. Sintering station6000. Casting station7000. Slip station8000. Calendering station9000. Drying station

Claims

Claims1. A method (100) for producing a half-cell (1), in particular formed by a double ceramic layer consisting of an electrode (4) and an electrolyte (5) coupled together, for a solid state fuel cell, comprising the following manufacturing steps:- a process (200) for producing a green electrode body (2);- a process (300) for producing a green electrolyte body (3);- a coupling step (400), in which the green electrode body (2) and the green electrolyte body (3) are coupled together;- a sintering step (500), following the coupling step (400), in which the green electrode body (2) and the green electrolyte body (3) coupled together are sintered so as to make the half-cell (1) formed by the coupled electrode (4) and electrolyte (5), wherein the process (200) for producing the green electrode body (2) comprises the following manufacturing steps:- a step (210) of producing a slip (20);- a step (220) of mixing the slip (20), so as to form a slurry (21);- a step (230) of extruding the slurry (21), so as to form an extruded slurry (22);- a step (240) of calendering the extruded slurry (22), so as to form the green electrode body (2), and wherein the process (300) for producing the green electrolyte body (3) comprises the following manufacturing steps:- a step (310) of producing of an electrolyte suspension (30);- a step (320) of depositing the electrolyte suspension (30), by means of slot die, preferably by means of curtain slot die, so as to make a film of green electrolyte body (3);- optionally, a drying step (330), in which the film of green electrolyte body (3) is dried.

2. A method (100) according to claim 1 , wherein the slip (20) is produced, in step (210), by means of the following components, preferably exclusively by means of the following components:- nickel oxide (NiO);- zirconium oxide (YSZ);- pore formers;- a binder;- a plasticizer.

3. A method (100) according to claim 1 , wherein the following components combined together so as to form the slip (20) have the following percentages by weight:- nickel oxide (NiO): 20-40%;- zirconium oxide (YSZ): 20-40%;- pore former: 1 -15%;- a binder: 30-50%;- a plasticizer: 1 -15%.

4. A method (100) according to claim 2 or 3, wherein the nickel oxide and zirconium oxide are in powder form, wherein, optionally, the nickel oxide powder and the zirconium oxide powder both have a Particle Size Distribution (PSD) less than 0.5 pm. and / or wherein the binder and the plasticizer both consist of polyacrylates and / or comprise ethylene copolymers or maleic acid copolymers or styrene copolymers or acrylate or methacrylate copolymers or vinyl acetate copolymers or polyvinyl butyral resins or vinyl acetal resins or vinyl resins or vinyl alcohol resins or waxes or cellulose, or a combination of the foregoing, and / or wherein the binder is a binder based on partially water-soluble acrylic polymers, where the binder has a solid load between 30% and 40%, and / or wherein the binder is an acrylic binder and / or a vinyl and / or a cellulose based on water or based on solvent, and / or wherein the water-based binders are formed from partially or completely water- soluble polymers or can be polymer emulsions, and / or wherein the plasticizer is a plasticizing agent consisting of 100% amine-containing polymer, and / or wherein the pore former is one or a combination of the following: starch, cellulose, acrylic polymers, carbon black.

5. A method (100) according to one of the preceding claims, wherein the step of (220) mixing the slip (20) includes mixing the components forming the slip (20) by means of a wet mixer (62), to form the slurry (21 ), wherein the components forming the slip (20) are mixed in the wet mixer (62) for a duration of time between 10 min and 30 min, or between 15 min and 25 min, or for about 20 min,and wherein, optionally, upon mixing, the step (220) of mixing the slip (20) includes degassing the slurry (21 ), so as to form a degassed slurry (21 ).

6. A method (100) according to one of the preceding claims, wherein the extruded slurry (22) has a thickness less than 2 mm, wherein, optionally, the step (230) in which the slurry (21 ) is extruded, so as to make the extruded slurry (22), is carried out following a degassing step.

7. A method (100) according to one of the preceding claims, wherein the calendering step (240) is carried out so as to make a green electrode body (2) of thickness between 50 pm and 10,000 pm, preferably less than or equal to about 350 pm ± 10 pm, or wherein the calendering step (240) is carried out so as to make an electrode body (2) of thickness between 50 pm and 10,000 pm, preferably less than or equal to about 350 pm ± 10 pm, or wherein the calendering step (240) is carried out so as to make an electrode body (2) of thickness of about 100 pm ± 10 pm, and / or wherein the calendering step (240) is carried out by means of at least one pair of rollers (80), one opposite the other with respect to the extruded slurry (22) to be extruded so as to form the electrode body (2), wherein, optionally, the calendering step (240) is carried out by a single pair of rollers (80), wherein, optionally, during the calendering step (240), at least one of the rollers (80) of the at least one pair of rollers (80), preferably each roller of the at least one pair of rollers (80), is heated, optionally to a temperature between 40°C and 50°C, and wherein, optionally, during the calendering step (240), the rollers (80) are rotated at a tangential speed between 5 m / min and 10 m / min, or of about 5 m / min.

8. A method (100) according to one of the preceding claims, wherein the drying step (330) is carried out following the step (400) of coupling between the film of green electrolyte body (3) and the green electrode body (2), and wherein the step (320) of depositing the electrolyte suspension (30), by means of slot die, includes depositing the electrolyte suspension (30) directly on the green electrode body (2).

9. A method (100) according to one of claims 1 to 7, wherein the drying step (330) iscarried out before the coupling step (400) between the green electrolyte body (3) and the green electrode body (2), wherein the step (320) of depositing the electrolyte suspension (30), by means of slot die, preferably by means of curtain slot die, includes depositing the electrolyte suspension (30) on a sliding support (32), preferably a flat polymer support, and wherein the coupling step (400) between the green electrolyte body (3) and the green electrode body (2) provides for the green electrolyte body (3) and the green electrode body (2) being both conveyed stacked in the direction of a rolling station (5000) comprising at least one pair of opposite rolling rollers, and wherein the coupling between the green electrode body (2) and the green electrolyte body (3) is carried out by the rolling rollers of the rolling station (5000).

10. A plant (1000) for producing a half-cell (1 ), in particular formed by a double ceramic layer consisting of an electrode (4) and an electrolyte (5) coupled together, for a solid state fuel cell, comprising:- an electrode station (2000), in which the production of a green electrode body (2) is carried out,- an electrolyte station (3000), in which the production of a green electrolyte body (3) is carried out,- a coupling station (4000), in which the coupling between the green electrode body (2) and the green electrolyte body (3) is carried out,- a sintering station (5000), in which the green electrode body (2) and the green electrolyte body (3) coupled together are sintered so as to make the half-cell (1 ) formed by coupled electrode (4) and electrolyte (5), wherein the electrode station (2000) comprises a slip station (7000), for producing, mixing and extruding a slip (20), so as to make an extruded slurry (22), wherein the electrode station (2000) further comprises a calendering station (8000) configured to calender the slip (20), in particular to calender the extruded slurry (22), so as to form the green electrode body (2), wherein the electrolyte station (3000) comprises a casting station (6000), for producing an electrolyte suspension (30) and for depositing the electrolyte suspension (30), by means of slot die, preferably by means of curtain slot die, so as to make a film of green electrolyte body (3), wherein, optionally, the electrolyte station (3000) further comprises a drying station (9000), for drying the film of green electrolyte body (3).

11. A plant (1000) according to claim 10, wherein the slip station (7000) comprises a wet mixer (62), wherein, optionally, the slip station (7000) comprises a hopper (61 ) fluidly connected to the wet mixer (62), wherein, optionally, the slip station (7000) comprises an extruder (63), configured to extrude the extruded slurry (22), wherein the extruder (63) is fluidly connected to the wet mixer (62), so as to extrude the extruded slurry (22) resulting from mixing the slip (20) in the wet mixer (62), and wherein, optionally, the slip station (7000) comprises a degasser, configured to degas the slip (20), so as to form the slurry (21 ).

12. A plant (1000) according to claim 10 or 1 1 , wherein the calendering station (8000) comprises at least one pair of opposite rollers, where at least one of the two rollers of the pair of opposite rollers is heated, wherein the calendering station (8000) is positioned downstream of the electrode station (2000) and upstream of the coupling station (4000).

13. A plant (1000) according to one of claims 10 to 12, wherein the drying station (9000) is positioned downstream of the coupling station (4000), wherein the electrode station (3000) is configured to deposit the electrolyte suspension (30) directly on the green electrode body (2).

14. A plant (1000) according to one of claims 10 to 12, wherein the drying station (9000) is positioned upstream of the coupling station (4000), wherein the electrode station (3000) is configured to deposit the electrolyte suspension (30) on a sliding support (32), preferably a flat polymer support.

15. A plant (1000) according to claim 14, comprising a rolling station (5000) comprising at least one pair of opposite rolling rollers, wherein the rolling station (5000) is configured to roll and couple the green electrolyte body (3) and the green electrode body (2) stacked and conveyed to the rolling station (5000).

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