CN112467165B

CN112467165B - Solid oxide battery with embedded regularly-arranged air passages and preparation method thereof

Info

Publication number: CN112467165B
Application number: CN202011341940.9A
Authority: CN
Inventors: 胡强; 吴剑
Original assignee: Zhejiang Zhen Tai Energy Technology Co ltd
Current assignee: Zhejiang Zhen Tai Energy Technology Co ltd
Priority date: 2020-11-25
Filing date: 2020-11-25
Publication date: 2022-03-11
Anticipated expiration: 2040-11-25
Also published as: CN112467165A

Abstract

The invention provides a solid oxide battery with embedded regularly-arranged air passages and a preparation method thereof, belonging to the technical field of electrochemistry. The battery body comprises an electrolyte layer and an inner electrode for providing the overall mechanical strength of the battery, wherein air passages are regularly arranged in the inner electrode, at least two side surfaces of the inner electrode are covered with side sealing members, and the outer surface of the electrolyte is provided with an outer surface part at least comprising an intermediate layer and an outer electrode. The regular microchannels embedded in the inner electrode enable the airflow resistance of gas flowing through the inner electrode to be remarkably reduced, and the regular microchannels dispersed in the inner electrode help the gas flowing through the inner electrode to be uniformly distributed to the interface regions of all electrolytes and electrodes, so that the electrode reaction is more sufficient, and the electrical efficiency of the battery is higher.

Description

Solid oxide battery with embedded regularly-arranged air passages and preparation method thereof

Technical Field

The invention belongs to the technical field of electrochemistry, relates to a solid oxide cell and a preparation method thereof, and particularly relates to a solid oxide cell with embedded regularly-arranged air passages and a preparation method thereof.

Background

1. Working principle of Solid Oxide Cell (SOC)

A Solid Oxide Cell (SOC) is a ceramic electrochemical device with Solid Oxide as electrolyte, which is composed of at least one layer of electrolyte and at least two electrodes, a so-called electrode-supported Solid Oxide Cell in which the electrodes provide the overall strength of the Cell, and a so-called electrolyte-supported Solid Oxide Cell in which the electrolyte provides the overall strength of the Cell. The electrolyte material is typically a doped stabilized zirconia, such as yttria doped stabilized zirconia (YSZ), Sc₂O₃Doped stabilized zirconia (ScSZ), scandia yttria doped stabilized zirconia (ScYSZ), scandia ceria doped stabilized zirconia (ScCeSZ), or calcia CaO Stabilized Zirconia (CSZ), etc., with 8 mol% yttria doped stabilized zirconia (8YSZ) being the most widely used. The electrolyte may also be an oxide of other fluorite structure, such as gadolinium oxide or oxygenSamarium-doped stabilized ceria, i.e., GDC (gdc) or SDC (samaria-doped ceria), and also perovskite-structured oxides such as LaSrGaMgO (LSGM), and the like, are known to those skilled in the art [ V.V.Kharton, et al, Transport properties of Solid oxide electrolyte ceramics: a brief review, Solid State Ionics,174:135-149(2004) ]. The material composition of the Electrode can be perovskite-structured oxide, such as LaSrMnO (LSM), LaSrCoFeO (LSCF), etc., fluorite-structured oxide, such as SDC, GDC, etc., or composite, such as composite of LSM and YSZ/CGO, etc., or composite of noble metal, such as Pt or composite containing noble metal, such as Pt and YSZ, which are known to those skilled in the art [ E.V.Tsis, et al, Electrode materials and reaction mechanisms in solid oxide fuel cells: a brief review, J.Solid State electrochemistry, 12: 1367-.

When a Solid Oxide Cell (SOC) is operated, the oxygen concentration in the vicinity of at least 2 electrodes differs by a factor of 10 or several orders of magnitude, and hereinafter, a gas having a higher oxygen concentration is referred to as an oxygen-enriched gas, an electrode operating in the oxygen-enriched gas is referred to as an oxygen-enriched electrode, a gas having a lower oxygen concentration is referred to as an oxygen-depleted gas, and the corresponding electrode is referred to as an oxygen-depleted electrode. The oxygen-enriched gas may comprise oxygen, nitrogen, argon, helium, but the most common and most typical oxygen-enriched gas is air, and the corresponding electrode is called an air electrode. The oxygen-depleted gas may contain a variety of gaseous components having fuel-or reducing-properties, such as carbon monoxide, methane, methanol, hydrogen, and the like, and typically an oxygen-depleted atmosphere such as a hydrogen/water mixture, a hydrogen/carbon monoxide/water vapor mixture, a carbon monoxide/carbon dioxide mixture, and a nitrogen oxide (NOx)/nitrogen mixture, and the corresponding electrodes are referred to as fuel electrodes. The oxygen-poor and oxygen-rich electrodes are separated by an electrolyte, which needs to be as dense and gas-tight as possible, and the electrical conductivity should be achieved by ionic rather than electron migration as possible, if there is electron conductivity in the electrolyte, short-circuit current will exist inside the cell, and the overall efficiency of the cell will be significantly reduced. Charge transport of the SOC electrolyte is generally conducted by oxygen ions as carriers, i.e., oxygen ions.

Solid Oxide Cell (SOC) operating at 500 to 100In the temperature range of 0 ℃, two working modes can be provided: a Solid Oxide Fuel Cell (SOFC mode) in a power generation mode and a Solid Oxide electrolyte Cell (SOEC mode) in an Electrolysis mode. When the SOC is operated in a power generation mode, namely, an SOFC mode, oxygen molecules in the oxygen-rich electrode undergo a reduction reaction to become oxygen ions (O)^2-) Oxygen ions diffuse from the oxygen-rich electrode side through the electrolyte and migrate to the oxygen-deficient electrode side, which in turn chemically react with fuel gas molecules in the oxygen-deficient electrode if fuel gas molecules are present in the oxygen-deficient electrode. Typically, if the gas component in the oxygen-deficient electrode is hydrogen (H)₂) And carbon monoxide (CO), the chemical reactions that occur in the oxygen-deficient electrode include:

H₂+O^2-→H₂O+2e-

CO+O^2--→CO₂+2e-

the macroscopic representation of the whole process is that oxygen molecules are transferred from the oxygen-enriched gas side to the oxygen-deficient gas side through the electrolyte, and the oxygen concentration difference between the oxygen-enriched gas and the oxygen-deficient gas is reduced. In the power generation mode, the SOC converts the chemical energy of the oxygen-deficient gas into electric energy and outputs the electric energy to the outside. Taking the hydrogen and oxygen electrodes as an example, the electrode reaction and the overall electrochemical reaction in SOFC mode can be expressed as:

anode (oxygen deficient electrode): h₂+O^2-→H₂O+2e-

Cathode (oxygen-rich electrode): 1/2O₂+2e-→O^2-

And (3) total reaction: h₂+1/2O₂→H₂O

If the electrode reaction products cannot be removed in time, the difference in oxygen concentration between the oxygen-rich gas and the oxygen-depleted gas decreases as the reaction proceeds.

Operating a Solid Oxide Cell (SOC) in an electrolysis mode, i.e., SOEC mode, with oxygen-depleted electrode gases, e.g., oxygen (O)₂) Water vapor (H)₂O), carbon dioxide (CO)₂) Nitrogen Oxide (NO)_x) Oxygen molecules or oxygen ions in the molecules are converted into oxygen ions (O) under the action of an external electric field^2-) Diffuses through the electrolyte to the oxygen-rich electrode and generates oxygen in the oxygen-rich electrodeThe reaction is converted into oxygen molecules. The macroscopic expression of the whole process is that oxygen molecules permeate electrolyte from the side of oxygen-poor gas with low oxygen concentration to the side of oxygen-rich gas with high oxygen concentration under the action of an external electric field, and the oxygen concentration difference between the oxygen-rich gas and the oxygen-poor gas is increased. In the electrolysis mode, the SOC absorbs externally input electrical energy and converts it into chemical energy of the oxygen-depleted gas. Taking the hydrogen and oxygen electrodes as an example, the SOEC mode electrode reaction and the overall electrochemical reaction can be expressed as:

anode (oxygen-enriched electrode): o is^2-→1/2O₂+2e-

Cathode (oxygen deficient electrode): h₂O+2e-→H₂+O^2-

And (3) total reaction: h₂O→H₂+1/2O₂

When the SOC is switched between the two modes, the electrical energy and the chemical energy can be converted into each other, which may be accompanied by heat release or absorption. Whether the SOC works in a power generation (SOFC) mode or an electrolysis (SOEC) mode, the SOC can accept external heat energy input or release heat energy to the outside, and therefore mutual conversion among electric energy, heat energy and chemical energy can be achieved by utilizing the SOC technology. When the SOC works in an electrolysis mode (SOEC), the electric energy is converted into chemical energy to be stored, and when the SOC works in a power generation mode (SOFC), the chemical energy of oxygen-poor gas is directly converted into the electric energy, so that the limitation of the Carnot cycle on the power generation efficiency in the heat engine process is avoided, and the efficient chemical energy utilization is realized.

Typical oxygen-depleted gases such as H₂And H₂Mixture of O, in power generation mode (SOFC), the total reaction of SOC is: h₂+1/2O₂→H₂O, in cell mode (SOEC), the overall reaction of SOC is: h₂O→H₂+1/2O₂. A typical oxygen-depleted gas may also be, for example, CO₂，H₂O，CO，H₂The resulting mixture, in generating mode, has a total reaction of SOC: h₂+1/2O₂→H₂O,2CO+O₂→2CO₂. In electrolytic mode (SOEC), the overall reaction of SOC is H₂O→H₂+1/2O₂，2CO₂→2CO+O₂Containing CO, H₂The electrolysis product of (a), also known as syngas, can be further converted to a series of derived hydrocarbons, such as methanol, ethanol, natural gas, gasoline, diesel, and other mature, widely used fuels or industrial feedstocks, via a mature fischer-tropsch synthesis process. When the gas component containing oxygen is nitrogen oxide NO_xOxysulfide SO_xAnd removing the pollutants by using the electrolytic technology of the SOC at the time of typical environmental pollutants, wherein the chemical process can be expressed as:

NO_x→N₂+O₂(x ═ 1 or 2) or SO_x→S+O₂(x ═ 1 or 2);

2. electrode reaction process of Solid Oxide Cell (SOC)

During the electrode reaction of SOC, at least three phases of substances participate in the reaction, namely oxygen ion (O)^2-) Electron (e)^-) And gaseous substances, e.g. molecular oxygen (O)₂) Water (H)₂O), hydrogen (H)₂) Carbon monoxide (CO), and the like. In order to continuously and rapidly perform the electrode reaction process, all substances participating in the reaction need to have a rapid inlet and outlet channel, for example, electrons and oxygen ions needed in the reaction process need to have a smooth transmission channel, that is, the electrode needs to contain a material with high electron conductivity and high oxygen ion conductivity, and also needs to have a certain porosity so as to facilitate the gas reactant at a high temperature to enter the electrode and the gas product of the electrode reaction to be discharged from the electrode. Known oxygen deficient electrode electron conductor materials include metallic nickel (Ni), gold (Au), platinum (Pt), palladium (Pd), rhodium (Rh), etc., and oxygen ion conductors include yttria doped stabilized zirconia (YSZ), scandia yttria doped stabilized zirconia (ScYSZ), scandia ceria doped stabilized zirconia (ScCeSZ) or samarium oxide (Sm)₂O₃) Gadolinium oxide (Gd)₂O₃) Etc. are doped with materials such as stable cerium oxide, e.g., SDC, GDC, etc. Some of the known oxygen ion conductor materials, such as doped stabilized cerium oxide, e.g., SDC, GDC, etc., have certain electron conductivity and are also commonly referred to as mixed conductors. Known oxygen-rich electrode electron conductor materials include LaSrMnO, LaSrCoO, LaSrCoFeO and the like under a high-temperature oxidizing atmosphereThe oxide with stable property and variable specific composition in a certain range can also be noble metal resisting high-temperature oxidation, such as silver (Ag), gold (Au), platinum (Pt), palladium (Pd), rhodium (Rh) and the like, and the noble metal resisting high-temperature oxidation can simultaneously have the function of a catalyst to accelerate the electrode reaction. The oxygen ion conductor of the oxygen-rich electrode comprises yttria-doped stabilized zirconia (YSZ), or samarium oxide (Sm)₂O₃) Gadolinium oxide (Gd)₂O₃) The doped stable cerium oxide material, such as SDC, GDC, etc., and the electron conductor material in the oxygen-rich electrode, such as LaSrCoO, LaSrCoFeO, etc., may also have a certain oxygen ion conductivity, and is also referred to in the industry as a mixed conductor. These are well known in the art [ E.V.Tsiaps, et al, Electrode materials and reactions in solid oxide fuel cells: a brief review, J.Solid State electrochemistry, 12: 1367-.

The conventional solid oxide cell is electrode supported, and the arrangement of gas channels in the electrode results in a portion of the electrode structure being hollow, which significantly reduces the structural strength of the cell, with larger gas channel volumes and larger gas channel ratios, and more uneven dimensions, and more strength reduction of the cell. Thus, in typical Solid Oxide Cell (SOC) technology, the size of the gas channels within the electrodes is small, below 1 micron, and in an irregular, dotted distribution [ m.b. mogensen, et al, Reversible solid-oxide cells for Clean and sustainable Energy, Clean Energy,1-27(2019) ].

The forming method of the gas channel in the electrode is generally to add a certain amount of pore-forming agent, such as graphite or starch, into the precursor powder slurry prepared by the electrode. These pore-forming agents and some solvents, such as alcohol, toluene and isopropanol, etc., are volatilized out of the electrode through high-temperature thermal decomposition during the high-temperature sintering preparation process of the battery, or are oxidized by oxygen in the air to generate gaseous oxides, such as carbon dioxide (CO)₂) Escape the electrode, and leave a gas channel in the electrode, which are well known in the art [ M.Chen, et al, microscopic definition of Ni/YSZ electrodes in solid oxide electrodes cells under high currentochem.Soc.,160:F883–F891(2013)】。

The tiny gas channels created by this method do not provide a rapid gas transfer path through the electrode, and the entire cell is therefore not provided with sufficient gas supply or timely exhaust gas production, and the conventional remedy is to create external gas channels outside the electrode, in which both oxygen-rich and oxygen-poor gases flow, i.e., oxygen-rich gas channels and oxygen-poor gas channels, which are surrounded by connecting plates, cells, and sealing glass [ m.b. mogensen, et al, Reversible solid-oxide cells for Clean and sustainable, Clean Energy,1-27(2019) ]. Fig. 1 shows a cross-sectional schematic structure of a cell unit of a typical Solid Oxide Cell (SOC) technology available in the open literature. It can be seen that in these typical configurations, since the diffusion flow rate of gases, particularly oxygen-poor gases, inside the electrode is very low, the gas flow rate leaking from the side edges of the cell is so small that the gaps between the connection plates and the electrode need only be sealed with a high-temperature sealing material, such as glass, without sealing the side edges of the electrode. In the scheme, the air flow main body flows in an air passage which is positioned outside the battery and has a regular shape, the geometric shape and the cross section shape of the air passage can be designed and manufactured as required, a gas raw material serving as a reactant is firstly diffused by an external air passage and enters an electrochemical reaction area of an electrode and electrolyte interface through a relatively compact electrode, and after electrode reaction occurs, a gas product serving as a product is diffused again and enters the external air passage through the relatively compact electrode to be removed and taken away.

In such designs, the gas passages in the electrodes are neither too large nor too large due to structural strength requirements, so that too low a gas flow delivery rate in the electrodes is one of the main factors limiting the electrode reaction rate, and to alleviate this problem, the electrodes in solid oxide cells are typically made very thin, typically 0.05-0.5mm thick, to minimize the diffusion of gas components into and out of the electrode, i.e., from the gas passages to the electrode and electrolyte interface. An electrode that is too thin, while helping to reduce the resistance to gas diffusion into and out of the electrode, can also significantly reduce the structural strength of the cell. The battery designed and manufactured in the mode is easy to break during the assembly and use of the stack, and the whole stack is scrapped due to failure, which is one of the main factors limiting the commercial large-scale use of the high-temperature solid oxide battery technology.

Disclosure of Invention

The present invention is directed to solving the above-mentioned problems of the prior art, and provides a solid oxide cell, which is to solve the technical problem of how to construct a clear low-resistance gas transmission channel for a rapid electrode reaction, and ensure that the cell has sufficient structural strength, and the solid oxide cell according to the present invention is also referred to as a "cell" herein.

The purpose of the invention can be realized by the following technical scheme: the solid oxide battery with the embedded regularly-arranged air passages is characterized in that a battery main body comprises a layer of electrolyte and an inner electrode which provides the overall mechanical strength of the battery, the regularly-arranged air passages are arranged inside the inner electrode, at least two side faces of the inner electrode are covered with side sealing members, outer surface components are arranged on the outer surface of the electrolyte, and the outer surface components at least comprise an intermediate layer and an outer electrode.

The oxygen partial pressure difference exists between the inner electrode and the outer electrode, so that the outer electrode can be designed as an oxygen-enriched electrode, the inner electrode can be designed as an oxygen-deficient electrode, the outer electrode can be designed as an oxygen-deficient electrode according to the operation requirement, and the inner electrode can be designed as an oxygen-enriched electrode.

In the solid oxide cell with the embedded regularly-arranged air channels, the cross-sectional equivalent diameter of a single air channel in the regularly-arranged air channels arranged in the inner electrode is 20-200 micrometers, preferably 30-60 micrometers.

In the above solid oxide battery with an embedded regularly arranged air passage, the outer surface component further includes an inner electrode plate and an outer electrode plate, the inner electrode is connected with the inner electrode plate through an inner bus line, the outer electrode is connected with the outer electrode plate through an outer bus line, and the conductivity of the inner bus line is not lower than that of the inner electrode, and the conductivity of the outer bus line is not lower than that of the outer electrode.

In the above solid oxide cell with embedded regularly arranged gas channels, the edge sealing member comprises several sub-layers, wherein at least one sub-layer is dense gas-impermeable and at least one rough gas-permeable sub-layer is arranged between the dense gas-impermeable sub-layer and the side of the cell.

In the above solid oxide cell with embedded regularly arranged gas channels, the outer surface part further comprises a plurality of external collector lines covering the surface of the external electrode, and the conductivity of the external collector lines is not lower than that of the external electrode.

In the above solid oxide cell having the regularly arranged gas passages embedded therein, the outer surface member further includes a protective layer covering at least one of the outer surface members.

In the solid oxide cell with the embedded regularly-arranged gas passages, an internal current collecting line is arranged between the side sealing member and the side face of the cell.

In the solid oxide battery with the embedded regularly-arranged air passages, at least part of the inner junction line is arranged on the surface of one side of the electrolyte where the outer electrode is located and is connected with the inner electrode through the opening in the electrolyte, and the surface of the opening of the electrolyte is covered with a sealing structure to completely cover and seal the junction of the inner junction line and the inner electrode at the opening of the electrolyte.

In the solid oxide battery with the embedded regularly-arranged air passages, the battery is in a strip sheet shape, the shape of the battery is gradually narrowed from an outer electrode area in the middle of the battery to at least two end faces of the battery, and the included angle between the tapered oblique edge and the straight edge of the outer electrode area in the middle of the battery is between 5 and 60 degrees.

The purpose of the invention can be realized by the following technical scheme: a preparation method of a high-temperature solid oxide battery is characterized by comprising the following steps:

(1) preparing a substrate: the components for forming the internal electrode and the electrolyte are added with proper auxiliary agents and solvents according to the proportion, and then the thin film substrate is prepared through casting operation, wherein part of the substrate is provided with gas outlet channel precursors according to requirements.

(2) Substrate lamination: aligning and stacking an electrolyte substrate, an inner electrode substrate with an air passage and an inner electrode substrate without an air passage according to a certain sequence, then putting the substrates into a vacuum bag for vacuumizing and sealing, putting a substrate assembly in the vacuum bag into a press, and pressing and fusing at high temperature to form a laminated body;

(3) cutting: placing the laminated body in a punching machine, and cutting the laminated body into a battery biscuit with a specified design appearance;

(4) and (3) sintering: the battery biscuit is placed in a high-temperature furnace and sintered at a proper heat treatment temperature, the sintered battery biscuit becomes a battery with higher strength, and meanwhile, the air channel precursor is gasified and escaped in the heat treatment process, so that regular and uniform embedded air channels are left in the battery.

(5) And (3) firing the middle layer: performing high-temperature heat treatment on the electrolytes on two sides of the battery after firing to form an intermediate layer;

(6) reduction: and (4) reducing the battery with the fired middle layer in a reducing furnace, and reducing the nickel oxide in the inner electrode into metallic nickel. The reduction operation can be performed before the cells are assembled into a stack, such as during the preparation of the cells, or can be performed by the integral reduction of the stack after the cells are assembled into a stack.

(7) Preparing an outer surface part: and printing outer surface components of the battery on the outer surface of the reduced battery, wherein the outer surface components comprise an outer current collecting line, an outer electrode polar plate, an inner electrode polar plate, an outer electrode bus line, an inner electrode bus line, a protective layer and the like, and the components can be completely printed on the intermediate layer or partially or completely printed on the surface of the electrolyte. The slurry used may be a mixture of ethanol and terpineol as solvent and graphite in an amount of about 0-10% as pore-forming agent.

(8) Preparing a side sealing component: for the cell to which the above process is applied, a side seal member may be prepared, which may comprise an inner and outer layer substructure, with an inner side seal layer applied first, preferably of graphite (C) or a magnesium silicate talc type (Mg)₆)[Si₈]O₂₀(OH)₄). After the inner layer of the side seal is dried, the outer layer of the side seal is coated on the inner layer of the side seal, preferably the material is potassium-calcium glass, and the component K₂O 12-18％，CaO 5-12％,SiO₂60-75％；

(9) And (3) heat treatment: heat treating the cell after printing of the outer surface features and coating of the edge seal, after which each outer surface feature forms a strong bond with its attachment and at least one sublayer of the edge seal member is densified; the preferred heat treatment temperature is 850 ℃ for 1 hour, the atmosphere is a reduction protective atmosphere, the hydrogen content is 5-60%, and the balance gas is nitrogen.

(10) Strengthening the electrode: the heat treated battery can be used for practical application, and electrode strengthening treatment can be performed for further improving the electrical property of the battery and reducing the internal resistance. Typical electrode strengthening treatment methods include processes such as dipping.

The solid oxide cell prepared according to the present invention may have the following constitutional features:

1) the internal electrode may have multiple layers, such as an active internal electrode and a supporting internal electrode, wherein the active internal electrode is more favorable for performing electrochemical reaction in terms of material design, and the supporting internal electrode is more favorable for improving the overall strength and/or conductivity of the battery in terms of material composition;

2) because of the embedded regular micro air passages, the number and the positions of the air passages can be adjusted according to the requirements and can be close to the electrolyte, the supply speed of raw material gas or the removal speed of product gas required by electrode reaction is not reduced along with the increase of the thickness of the inner electrode, but is increased along with the increase of the thickness of the inner electrode, and simultaneously, the integral conductance of the inner electrode and the strength of the battery are also increased due to the increase of the thickness of the inner electrode;

3) the inner air channels are regularly arranged, and the equivalent diameter of the cross section of each air channel is 20-200 microns, preferably 30-60 microns. Too big air flue cross-section can reduce battery intensity, makes the battery breakable, shows to reduce the battery yield, and the air current pressure drop that the during operation of battery will be caused to the air flue of undersize is too big. According to the actual test result, the equivalent diameter of the single air passage should be controlled within the range of 30-60 microns. Meanwhile, the number of air passages contained in a single battery/cell is more than 6 so as to ensure that the battery has certain ventilation capacity and can have enough power;

4) the side seal members of the cell may contain multiple sub-structures that differ in material and microstructure. Different substructures can have different functions, for example, the innermost substructure is mainly used for enhancing contact with the sealing bottom surface and has lower requirement on air tightness, the outermost structure is used for sealing with high requirement on air tightness, more substructures can be embedded in the outermost and innermost substructures according to the requirement on functions, but in any case, at least one of the sublayers of the side sealing component is dense and airtight;

5) the current collecting structure can contain a layer of inner electrode current collecting structure, the conductivity of the current collecting structure is higher, and the current collecting structure is used for reducing the current collecting resistance of the inner electrode. The inner electrode current collecting structure may be located within the sealing layer, attached to the side of the inner electrode, or may be located elsewhere, such as on the surface of the battery. Preferred internal electrode current collecting structure materials are coatings based on silver (Ag) or nickel (Ni). The material cost of silver and nickel is far lower than that of noble metals such as Pt and the like, the conductivity is high, and the silver and nickel are only used for coating the side face or the side face of the battery, so that the structural requirement is avoided, and a large material configuration component adjustment space is provided. The conductivity of the inner electrode current collecting structure may be much greater than that of the commonly used nickel electrode material. For example, the conductivity of a nickel electrode is about 250S/cm, and the current collecting coatings of silver and nickel can respectively realize 6 x 10⁵S/cm and 1X 10⁵Conductivity of S/cm. In the same case, the line resistance of the side current collecting coating with silver (Ag) material is about 17mOhm, and the line resistance of the side current collecting coating with nickel (Ni) material is about 100mOhm (for example, 1mm line width, 0.1mm thickness, 10cm length), both of which are significantly less than the current collecting resistance of the nickel electrode of about 400 mOhm. Obviously, by adopting the inner electrode current collecting structure, the current collecting resistance of the inner electrode of the battery can be obviously reduced at lower cost.

6) The cell may adopt a tapered profile design. I.e., the cell has a wider active surface at the hot end, but the width of the cell gradually decreases in the direction of the inner electrode gas flow to the cold end of the cell. The tapered design can enable the battery to have the largest working area in a high-temperature region, the heat transfer sectional area of the battery is gradually smaller in a transition region from high temperature to low temperature, and the heat loss caused by the heat conduction of the battery is also reduced, so that the power output of the battery can be effectively improved. According to experimental results, the output power of the battery cell using the tapered design may be about 10% more than that of the battery cell using the rectangular constant-width design. However, a tapered cell design may also result in increased internal electrode gas flow resistance, even if the pressure drop of the internal electrode gas as it flows through the cell is increased. Practical tests and hydromechanical simulation calculation show that when the included angle between the tapered oblique edge of the battery and the straight edge of the hot-end working face is between 5 and 60 degrees, preferably between 10 and 30 degrees, the pressure drop of the inner electrode flowing through the battery is small.

According to the functional division, the battery according to the present invention may further include a plurality of constituent members, wherein the structural member located outside the battery, except for the intermediate layer, directly or indirectly attached to the electrolyte is referred to as an outer surface member of the battery, and the functions and material compositions of the respective members are as follows:

1) inner and outer electrode plates: the inner and outer electrodes of the battery, which realize the interface part electrically connected to the external device, are preferably made of a material having high electrical conductivity and being resistant to oxidation, such as a material based on silver (Ag), nickel (Ni), gold (Au), platinum (Pt), rhodium (Ph), palladium (Pd), chromium (Cr), tungsten (W), etc.

2) An inner electrode: the gas flowing through the inner electrode is provided with a place for electrochemical reaction and electrochemical process of the inner electrode, the structural strength of the whole battery is provided, and the current transmission channel of the inner electrode is at least partially provided. The inner electrode may contain different sublayer structures to perform three functions of electrochemical reaction, strength support and current transmission, respectively. The different inner electrode sub-layers may be made of materials of similar composition, preferably, the inner electrode comprises two sub-layers of an active inner electrode and a supporting inner electrode, the composition of the active inner electrode is designed to be more favorable for electrochemical reaction, such as containing 50-60% of 8YSZ and 40-50% of metallic nickel (Ni), and the composition of the supporting inner electrode is designed to be more favorable for electron transmission and strength support of the battery, such as 30-50% of 3YSZ and 50-70% of Ni. The internal electrode may further contain a small amount of other additives such as platinum, cerium oxide, aluminum oxide, magnesium oxide, lanthanum oxide, strontium titanate, or a composite based on these additives, based on the basic composition of Ni and YSZ. The content of these additives is usually below 5%, but it can bring better electrochemical activity and better high temperature stability to the inner electrode.

3) Airway: the inner electrode is provided with a raw material supply and a product removal channel required for the electrode process. The gas channel extends over the entire inner electrode and to the cell edge. The equivalent diameter of the single air passage is 20-200 microns, preferably 30-60 microns, so that the air passage can be ensured to be distributed over the inner electrode without remarkably reducing the strength of the inner electrode. The inner electrode with the structured micro air channel arrangement has larger thickness, more air channels, more air supply quantity of the battery and higher strength.

4) Electrolyte: and a diaphragm between the inner electrode and the outer electrode provides a channel for ions required by continuous electrode reaction. The smaller the electron conductivity of the electrolyte, the better, and the more airtight the electrolyte. Preferably, the electrolyte is based on doped stabilized zirconia, especially yttria doped stabilized zirconia (YSZ).

5) An internal collector line: and a component which is tightly attached to the inner electrode or is a part of the inner electrode per se and provides a required electron rapid transportation channel for the electrode reaction of the inner electrode. The internal current collecting lines arranged at proper positions by proper materials can effectively increase the overall conductivity of the internal electrodes, so that the battery has lower internal resistance, particularly current collecting internal resistance. Preferably, the internal collector has a higher electron conductivity than the internal electrode, and is made of a high temperature oxidation resistant metal material such as silver (Ag), nickel (Ni), gold (Au), platinum (Pt), rhodium (Ph), palladium (Pd), chromium (Cr), tungsten (W), or an alloy thereof, or an oxide such as strontium titanate having a high temperature conductivity under a reducing atmosphere. Preferably, the internal current collection lines are arranged on the cell side of the end faces of the cell where the non-gases enter and exit, but may also be arranged elsewhere in the cell, such as on the cell surface where the external electrodes are located. The internal collector lines may be either dedicated cell components or may be carried by the internal electrodes themselves.

6) An internal bus line: and the electronic transmission channel is communicated with the inner current collecting line and the inner electrode polar plate. Because the inner electrode current is carried, the inner bus line generally has a larger cross-sectional area and higher conductivity so as to ensure that the resistance is smaller when the electron transmission is carried out. Preferably, the internal bus bar has a higher electron conductivity than the internal electrode, and may be composed of a material resistant to high-temperature oxidation, such as silver (Ag), nickel (Ni), gold (Au), platinum (Pt), rhodium (Ph), palladium (Pd), chromium (Cr), tungsten (W), copper (Cu), and the like, and alloys thereof, and composites of these metal materials with an oxide having high-temperature conductivity, such as strontium titanate, doped stabilized cerium oxide, doped stabilized zirconium oxide, and the like, which are known to have high-temperature conductivity.

7) An intermediate layer: contact of the cell's exterior surface components with the electrolyte is facilitated, and components of these exterior surface components that may react with the electrolyte at high temperatures are mitigated or avoided. The electrolyte is usually more compact and smooth after being sintered at high temperature, which is not favorable for realizing and maintaining good contact between the outer surface part of the battery and the electrolyte. In addition, during the preparation process and the use process of the battery, due to the high temperature, such as the highest temperature in the battery preparation process can reach 1500 ℃, the long-term use of the battery is also maintained in the high temperature range of 500-1000 ℃, and under the condition, the outer surface part of the battery is likely to cause the performance reduction of the battery due to the reaction with the electrolyte. These problems can therefore be avoided or alleviated by the introduction of an intermediate layer. The intermediate layer is chemically stable to the electrolyte and the outer surface components of the cell at high temperatures, and has a relatively rough surface after preparation, achieving good contact with the outer surface components. The intermediate layer may be prepared not only between the outer electrode and the electrolyte but also between all of the outer surface parts of the cell, which may include: external electrodes, internal/external electrode plates, internal/external bus lines, protective layers, sealing structures, and the like. Preferably, the material of the intermediate layer consists of a composite material based on doped ceria (such as SDC or GDC), or doped ceria (SDC or GDC) and doped zirconia (such as YSZ, ScYSZ).

8) External electrode: provides a reaction site for the gas flowing through the outside of the cell to generate electrochemical reaction and perform the process of the external electrode. Preferably, the external electrode material is a composite material formed by doped cerium oxide and oxidation-resistant metal such as Ag, Pt, Pd and the like, and also can be an electrode material of the known solid oxide battery technology such as oxides of LaSrMnO, LaSrCoFeO, LaNiFeO and the like or a composite material based on the oxides. In addition, the preparation process of the external electrode may include various known electrode strengthening processes, such as impregnation of active oxides, and the like.

9) An external collector: and a component which is tightly attached to the external electrode or is a part of the external electrode per se and provides an electron rapid transmission channel required by the external electrode for carrying out electrode reaction. Preferably, the external collector is composed of a composite based on a high temperature oxidation resistant metal, such as silver (Ag), nickel (Ni), gold (Au), platinum (Pt), rhodium (Ph), palladium (Pd), chromium (Cr), tungsten (W), etc., and alloys thereof, and an oxide having high temperature conductivity, such as strontium titanate, doped stabilized cerium oxide, doped stabilized zirconium oxide, etc., which are known as oxide materials having high temperature conductivity. Preferably, the outer current collector is arranged at the outer surface of the outer electrode, but may also be located at the inner surface, i.e. between the outer electrode and the electrolyte, or between the outer electrode and the intermediate layer. Preferably, the external current collecting line is in the form of a grid to enhance the current collecting effect.

10) Protective layer: and a structure for directly or indirectly covering and protecting each of the outer surface parts including the external electrode. The outer surface components that the protective layer may cover include: external electrodes, internal/external electrode plates, internal/external bus lines, a protective layer, a side sealing member, a sealing structure and the like. The protective layer can increase the high-temperature stability of each external surface component of the battery including the external electrode by inhibiting the volatilization loss of the effective components, and can also increase the working stability of the battery by enhancing the tolerance of each external surface component to external gas impurities, such as dust or water vapor, or other gas impurities which are easy to poison and lose efficacy of the external surface component of the battery, such as aromatic hydrocarbon, silane or CO and the like, by a physical filtration or chemical absorption method, thereby effectively prolonging the service life of the battery. Preferably, the protective layer may be prepared from an oxide and/or metal material based on alumina, zirconia, ceria, silica, platinum, palladium, rhodium, etc., which can maintain stable properties under high temperature conditions.

11) An outer bus bar: and the electronic transmission channel is communicated with the external collector wire and the external electrode polar plate. Because the outer electrode current is carried, the outer bus wire generally has a larger cross-sectional area and higher conductivity, so as to ensure that the resistance is smaller when the electron is transmitted. Preferably, the outer bus bar is composed of a composite of a metal having higher electron conductivity than the outer electrode material, such as silver (Ag), nickel (Ni), gold (Au), platinum (Pt), rhodium (Ph), palladium (Pd), chromium (Cr), tungsten (W), copper (Cu), etc., and an alloy thereof, and an oxide having high-temperature conductivity, such as strontium titanate, doped stabilized cerium oxide, doped stabilized zirconium oxide, etc., which are known as oxide materials having high-temperature conductivity.

12) Side seal component: the structure for gas-isolated sealing of the non-gas inlet and outlet end faces of the battery may comprise a plurality of sublayer mechanisms. Preferably, the battery comprises an inner side sealing sublayer and an outer side sealing sublayer, wherein the inner side sealing sublayer covers the side face of the battery inner electrode and is positioned between the inner electrode and the outer side sealing sublayer, so that the resistance of the inner electrode to airflow leakage from the side edge of the battery is increased, the inner electrode is in good contact with the outer side sealing sublayer, the inner electrode and the outer side sealing sublayer are chemically stable, and the structural damage of the inner electrode and the outer side sealing sublayer caused by chemical reaction at high temperature is avoided. Preferably, the material of the inner side seal layer can be graphite (C) or magnesium silicate talc material, such as (Mg)₆)[Si₈]O₂₀(OH)₄And the like. The side seal outer layer is positioned on the outermost layer of the battery side seal component and is a compact seal structure for preventing gas flowing through the inner electrode gas channel from leaking to the outside of the battery. Preferably, the outer side seal layer may be composed of a graphite or potash-lime glass based material. If the potassium-calcium glass is used, the preferable component proportion range is as follows: k₂O 12-18％CaO 5-12％,SiO₂60-75％。

It should be noted that the above components are divided based on the difference in the functions performed, not their positions or material compositions. In practice, different functional components may be made of materials having similar, or even identical, properties and the same manufacturing process, in which case the different components may have the same, or similar, structural characteristics, which renders them indistinguishable in their microstructural characteristics. For example, the external electrodes, the external collector lines, and the external bus lines, even if they serve different functions, may be fabricated using the same material, e.g., a composite material of 70% Ag and 30% SDC, and the same fabrication process, e.g., screen printing, in the same operation step.

Compared with the prior art, the invention has the following advantages:

1. the regular micro-channels embedded in the inner electrode enable the airflow resistance of gas flowing through the inner electrode to be remarkably reduced, and the regular micro-channels dispersed in the inner electrode are beneficial to the gas flowing through the inner electrode to be uniformly distributed to all interface areas of electrolyte and electrodes, so that the electrode reaction is more sufficient, and the electrical efficiency of the cell is higher;

2. the inner electrode may include multiple sublayers such as an active inner electrode that is more formulated to facilitate the electrochemical reaction and a supporting inner electrode that is more compositionally conducive to improving the overall strength and/or conductivity of the cell.

3. The inner electrode can also be used as the support of the electrolyte, and the higher yield can be ensured even if the thickness of the electrolyte is relatively thinner;

4. the side sealing layer is of a multilayer structure, the inner sublayer can increase the leakage resistance of gas flowing through the inner electrode, the material of the outer sublayer is different from that of the inner sublayer in composition and structure, the side sealing layer can better seal the decompressed leakage gas, and the structural strength can be better maintained.

Drawings

Fig. 1 is a schematic cross-sectional view of a stack unit of a known typical solid oxide cell.

Fig. 2 is a top view structural diagram of the first embodiment of the present invention.

Fig. 3 is a side view of the end of the first embodiment of the present invention.

Fig. 4 is a top view structural diagram of the second embodiment of the present invention.

Fig. 5 is a side view structural view of an end portion of the second embodiment of the present invention.

Fig. 6 is an exploded view of a second embodiment of the present invention.

Fig. 7 is a sectional structural view of the third embodiment of the present invention.

Fig. 8 is a top view structural diagram of the fourth embodiment of the present invention.

Fig. 9 is a top view structural diagram of a fifth embodiment of the present invention.

In the figure, 1, electrolyte; 2. an inner electrode; 201. supporting the inner electrode; 202. an active inner electrode; 3. an outer electrode; 4. a side seal member; 401. a side seal inner layer; 402. side sealing the outer layer; 5. an intermediate layer; 6. an inner electrode pad; 7. an outer electrode plate; 8. an inner bus line; 9. an outer bus line; 10. a sealing structure; 11. an airway; 12. an external collector line; 13. a protective layer; 14. an inner collector line; 15. and (7) connecting the sheets.

Detailed Description

The following are specific embodiments of the present invention and are further described with reference to the drawings, but the present invention is not limited to these embodiments.

As shown in fig. 2 to fig. 3, the solid oxide cell with embedded regularly arranged gas channels in the first embodiment includes a layer of electrolyte 1, an active internal electrode 202 and a supporting internal electrode 201 in the thickness direction, the supporting electrode 201 is embedded with a plurality of regularly arranged gas channels 11, all sides of the supporting internal electrode 201 are covered with side sealing members 4, and the other surface of the electrolyte 1 opposite to the supporting internal electrode 201 is provided with an external electrode 3. The side seal members 4 cover the four sides of the cell and comprise two sublayers of an inner side seal layer 401 and an outer side seal layer 402, the materials of the inner side seal layer 401 and the outer side seal layer 402 are different from the materials of the electrolyte 1 and the supporting inner electrode 201, while the outer side seal layer 402 is dense and gas-impermeable and the inner side seal layer 401 is rough and gas-permeable. The inner current collecting line 14 is sandwiched between the side seal inner layer 401 and the supporting inner electrode 201, and extends to the outer surface of the inner electrode 2.

The cell shown in this example was prepared as follows:

1) and (4) preparing a substrate. Substrates are classified into three categories: the preparation process of the support inner electrode substrate, the active inner electrode substrate and the electrolyte substrate comprises the following steps:

(a) and (4) preparing slurry. Ceramic fine powder, such as oxide fine powder of 8YSZ, NiO, GDC and the like, is added with a proper amount of organic auxiliary agents and solvents, such as PVB, triethanolamine, ethanol and the like, and after ball milling and mixing, the ceramic fine powder is uniformly dispersed to prepare stable slurry. In a typical active internal electrode slurry, the content of solid active ingredients is 8 YSZ: NiO: GDC is 5:4:1 (by weight) and has a variation of about 20%, and in a typical supported inner electrode paste, the content of solid active ingredient is 8 YSZ: NiO: al (Al)₂O₃3.5:5.5:1 (by weight), and about 20% of the range. The content of nickel oxide (NiO) in the supporting inner electrode is slightly higher so that the supporting inner electrode has higher conductivity after being reduced. In a typical electrolyte slurry, the solid active ingredient is 8YSZ or ScYSZ.

(b) And (4) preparing a substrate. Preparing the slurry in the step (a) into thin films of an electrolyte and two internal electrodes by a casting machine, wherein the thickness of the typical electrolyte thin film is 20-40 microns, and the thickness of the typical two internal electrode thin films is 100-200 microns. The film is dried at 60 ℃ for 2 hours and then cut into sheets of a certain size, such as 270X 220mm, which are called substrates. Accordingly, a substrate prepared from the active internal electrode paste is referred to as an active internal electrode substrate, a substrate prepared from the supporting internal electrode paste is referred to as a supporting internal electrode substrate, and a substrate prepared from the electrolyte paste is referred to as an electrolyte substrate.

(c) And (4) preparing an airway precursor. Preparing an air passage precursor of the battery cell on a substrate supporting the inner electrode. Typical airway precursors are slurries containing fine powders of graphite, starch or other polymeric materials such as PTFE, PVC, etc., preferably in the range of 5-30% solids such as graphite, starch, PTFE, PVC, etc., and the solvent is terpineol. Methods for preparing the precursor paste on the supporting or active inner electrode substrate include screen printing and high temperature lamination, among other methods known in the art.

2) The substrate is laminated. Aligning and sequentially overlapping the electrolyte substrate, the active internal electrode substrate, the supporting internal electrode substrate containing the gas channel precursor and the supporting internal electrode substrate without the gas channel according to the sequence shown in figure 4, and then putting the substrates into a vacuum bag for vacuumizing and sealing. Subsequently, the sealed vacuum bag containing the substrate assembly was placed in an isostatic press, and was taken out after applying a pressure of 20MPa in a water bath at 75 ℃ for 5 minutes. By the isostatic pressing process, the individual substrates in the assembly are fused to each other to form a laminated body. The laminate is about 2mm thick and the component layers can no longer be partially or fully separated into individual substrates.

3) And (6) cutting. The laminated body prepared by the steps is placed in a punching machine and is cut into a cell biscuit with a specified design appearance through a punching die. Typically, a laminate can be cut into 3 cell blanks having an outer shape of 65 x 260 mm.

4) And (5) sintering. And placing the cell biscuit in a high-temperature furnace, and selecting a proper heat treatment temperature for high-temperature sintering. After high-temperature sintering, such as sintering at 1400 ℃ for 2 hours, the biscuit is sintered into a cell with higher strength. Meanwhile, in the heat treatment process, because the air flue precursor is gasified and escaped, the regular and uniform embedded air flue is left in the battery cell.

5) And firing the intermediate layer. And printing the intermediate layers on the electrolytes on the two sides of the battery core after firing. A typical interlayer material is doped ceria, such as GDC or SDC, and the printing process can be a screen printing process, which is well known in the art. And drying the battery cell printed with the middle layer at 90 ℃ for 1 hour, then placing the battery cell in a high-temperature furnace, then raising the furnace temperature to 1300 ℃, and after 2 hours of calcination, reducing the furnace temperature and controlling the cooling speed not to exceed 5 ℃ per minute. And when the furnace temperature is reduced to room temperature, taking out the battery cell, and firmly firing the middle layers on the two surfaces on the outer surface of the electrolyte of the battery cell.

6) And (4) reducing. And (4) placing the battery cell sintered by the middle layer in a reducing furnace for reduction. The reducing atmosphere is mixed gas of hydrogen and nitrogen, wherein the content of hydrogen is 70-100%, the content of nitrogen is 0-30%, and the reducing condition is 680 ℃ for 6 hours. Through reduction operation, the nickel oxide in the supporting inner electrode is reduced into metallic nickel, so that a gas channel is formed in the supporting inner electrode, and meanwhile, because the formed metallic nickel is an electronic conductor, the reduced supporting inner electrode has conductivity, and an electronic transmission channel connected between a battery core high-temperature area for performing electrochemical reaction and a supporting inner electrode pole plate for connecting with the outside can be formed. It should be noted here that the cell reduction operation can be accomplished by an integral reduction of the stack after the cells are assembled into a stack, in addition to being accomplished prior to the assembly of the cells into a stack as shown herein.

7) Preparing an outer surface part. And printing outer surface components of the cell on the outer surface of the reduced cell, wherein the outer surface components comprise a counter current collecting line, a counter electrode polar plate, a supporting inner electrode polar plate, a counter electrode bus line, a supporting inner electrode bus line, a protective layer and the like, and the components can be completely printed on the intermediate layer or partially or completely printed on the surface of electrolyte.

The components of the outer surface components of the battery cell, such as the content of doped stable cerium oxide (SDC or GDC) is 5-20%, the content of silver is 80-95%, and the components of the outer collector lines, the outer electrode polar plates, the inner electrode polar plates, the outer electrode bus lines and the inner electrode bus lines are the same or close to each other, and can be printed in the same step by using the same screen plate. The external electrode comprises the components of 30-55% of doped stable cerium oxide (SDC or GDC) and 45-70% of silver, and the external electrode can be printed before or after the external collector line is printed, but a drying process is carried out between the external collector line and the external collector line, and the drying condition is that the external collector line is dried by hot air at 90 ℃ for 1 hour. The protective layer is composed of alumina, zirconia, silica or various composite materials based on oxides, the preferred component is alumina, and slurry prepared by the oxides is printed or sprayed on other external surface parts after being dried. The various slurries used in the step can use a mixture of ethanol and terpineol as a solvent and graphite with the content of about 0-10% as a pore-forming agent.

8) And preparing an internal collector line. And preparing an internal current collecting line for the battery cell after printing of the components such as the external electrode and the like. Coating the side surface of the battery cell with slurry of an internal collector wire, wherein the basic components are 5-20% of doped stable cerium oxide (SDC or GDC) and 80-95% of silver, and after the internal collector wire is coated, the battery cell needs to be dried by hot air at 90 ℃ for 1 hour until the slurry is cured.

9) And preparing a side seal component. Coating a side seal inner layer on the battery core after the above process, wherein the side seal inner layer can be coated on the inner current collecting line coating and comprises graphite as the basic componentOr magnesium silicate talc-based materials ((Mg)₆)[Si₈]O₂₀(OH)₄) After the side seal inner layer is dried by hot air at 90 ℃ for 1 hour, the side seal outer layer is continuously coated on the side seal inner layer, the basic material is graphite or potassium-calcium glass, and the component K₂O 12-18％CaO 5-12％,SiO₂60-75％。

10) And (6) heat treatment. And (3) carrying out heat treatment on the battery core subjected to printing and side sealing coating of the outer surface parts, wherein after the heat treatment, each outer surface part forms firm connection with the attachment of the outer surface part, and at least the outermost layer of the side sealing component is densified. The preferable heat treatment temperature is 850 ℃ for 1 hour, the atmosphere is a reduction protective atmosphere, the hydrogen content is 5-60%, and the balance gas is nitrogen.

11) And (5) strengthening the electrode. The electric core after heat treatment can be used for practical application, and electrode strengthening treatment can be carried out for further improving the electric performance of the electric core and reducing the internal resistance. Typical electrode strengthening treatments are impregnation. For example, SDC (samaria doped ceria) impregnation can be performed by first impregnating Sm (NO)₃)₂，Ce(NO₃)₄According to a certain Sm₂O₃:CeO₂(e.g., Sm in a molar ratio of 20: 80₂O₃:CeO₂) Dissolving in water solution (or dilute nitric acid with pH of about 5), coating the solution on internal and external electrodes, and heating to 500 or 300 deg.C for 20 min to obtain Sm (NO)₃)₂，Ce(NO₃)₄Will decompose to form Sm with a certain proportion₂O₃:CeO₂Doping the stable compound SDC. This process can be repeated 3-5 times to increase the amount of SDC impregnated. SDC is a known oxide with good catalytic activity and mixed ion/electron conductance. After the dipping treatment, the SDC can be dispersed into the electrode at a very fine nanometer scale, for example, less than 100 nm, so as to greatly expand the reaction region of the electrode process, i.e., TPB (Triple Phase Boundary, i.e., gas-solid electrochemical field), significantly reduce the resistance of the electrode process, and reduce the internal resistance of the cell, which is a known technique in the art.

Example two:

referring to fig. 4 to 6, in the second embodiment, the outer surface of the electrolyte 1 is provided with outer surface components including the intermediate layer 5, the inner electrode pad 6 and the outer electrode pad 7. The inner electrode 2 is connected with the inner electrode plate 6 through an inner bus 8, and the outer electrode 3 is connected with the outer electrode plate 7 through an outer bus 9. The intermediate layer 5 may cover the entire outer surface of the electrolyte 1 or may partially cover the electrolyte 1. The inner electrode polar plate 6 and the outer electrode polar plate 7 are respectively arranged at two ends of the battery, and the inner converging line 8 is positioned on the end surface of the battery core.

The outer surface of the outer electrode 3 is provided with an outer current collecting line 12 which is positioned on the outer surface of the outer electrode 3, and the outer current collecting line 12 and the outer electrode 3 are covered with a protective layer 13. The inner electrode polar plate 6, the outer electrode polar plate 7, the outer electrode 3, the outer bus wire 9 and the like are uniformly distributed on the middle layer 5 and are not in direct contact with the electrolyte 1. The internal current collecting lines 14 are buried in the side seal member 4, and the side seal member 4 covers only two opposite side edges in the present embodiment.

Example three:

referring to fig. 7, the cross-sectional structure of the solid oxide cell with embedded regularly arranged gas channels in the third embodiment is similar to that of the first embodiment, but in this embodiment, the internal current collecting line 14 is arranged on the outer surface of the internal electrode 2, not on the side of the cell, and sandwiched between the cell side and the side sealing member 4.

Example four:

referring to fig. 8, the structure of the fourth embodiment is substantially the same as that of the second embodiment, except that the battery of the fourth embodiment adopts a tapered design at both ends, and the included angle α between the tapered oblique edge and the straight edge of the working surface of the external electrode is between 5 and 60 degrees, preferably between 10 and 30 degrees. The external current collecting line 12 of the fourth embodiment is located on the outer surface of the external electrode 3, and a connecting sheet 15 for external connection is welded on the external electrode polar plate 7, and preferably, the connecting sheet 15 is made of a material based on copper, nickel, gold and silver.

Example five:

referring to fig. 9, the fifth embodiment has substantially the same structure as the fourth embodiment, except that the inner bus line 8 of the fifth embodiment is connected to the inner electrode 2 through the opening on the surface of the electrolyte 1, and the opening of the electrolyte 1 is covered with a sealing structure 10 to completely cover and seal the junction of the inner bus line 8 and the inner electrode 2 at the opening of the electrolyte 1, so as to ensure that the gas flowing through the inner electrode does not leak from the opening to the side of the outer electrode 3 of the electrolyte.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Various modifications or additions may be made to the described embodiments or alternatives may be employed by those skilled in the art without departing from the spirit or ambit of the invention as defined in the appended claims.

Claims

1. A solid oxide battery with embedded air passages arranged regularly is characterized in that a battery body comprises a layer of electrolyte and an inner electrode for providing the overall mechanical strength of the battery, the inner electrode is internally provided with the air passages arranged regularly, at least two side faces of the inner electrode are covered with side sealing members, an outer surface component is arranged on the outer surface of the electrolyte, the outer surface component at least comprises a middle layer and an outer electrode, the side sealing members comprise a plurality of sub-layers, at least one sub-layer is compact and airtight, at least one rough and air-permeable sub-layer is arranged between the compact and airtight sub-layer and the side face of the battery, the outer surface component further comprises an inner electrode polar plate and an outer electrode polar plate, the inner electrode is connected with the inner electrode polar plate through an inner bus line, and the outer electrode is connected with the outer electrode polar plate through an outer bus line, the conductivity of the inner bus line is not lower than that of the inner electrode, the conductivity of the outer bus line is not lower than that of the outer electrode, at least part of the inner bus line is arranged on the surface of one side of the electrolyte where the outer electrode is located and is connected with the inner electrode through an opening in the electrolyte, and a sealing structure covers the surface of the opening of the electrolyte and completely covers and seals the joint of the inner bus line and the inner electrode at the opening of the electrolyte.

2. The solid oxide cell with embedded regularly-arranged air passages as claimed in claim 1, wherein the cross-sectional equivalent diameter dimension of a single air passage in the regularly-arranged air passages arranged in the inner electrode is between 20-200 microns.

3. The solid oxide cell with embedded regularly arranged gas passages as claimed in claim 1, characterized in that the outer surface part further comprises several outer collector lines covering the surface of the outer electrodes, and the electrical conductivity of the outer collector lines is not lower than that of the outer electrodes.

4. The solid oxide cell with embedded regularly arranged gas passages as claimed in claim 3, characterized in that the outer surface parts further comprise a protective layer covering at least one of the outer surface parts.

5. The solid oxide cell with embedded regularly arranged gas channels as claimed in claim 1, characterized in that an internal current collecting line is provided between the side sealing member and the side of the cell.

6. The solid oxide cell with embedded regularly arranged gas channels as claimed in claim 1, characterized in that the cell is in the form of a long strip, the shape of the cell is gradually narrowed from the outer electrode area in the middle of the cell to at least two end faces of the cell, and the included angle between the tapered oblique side and the straight edge of the outer electrode area in the middle of the cell is between 5 ° and 60 °.

7. A method for preparing a solid oxide cell with embedded regularly arranged gas channels according to any of claims 1 to 6, characterized in that it comprises the following steps:

(1) preparing a substrate: adding proper auxiliary agents and solvents into the components forming the inner electrode and the electrolyte according to a proportion, and preparing the components into a film substrate through casting operation;

(2) substrate lamination: aligning and stacking an electrolyte substrate, an inner electrode substrate with an air passage and an inner electrode substrate without an air passage according to a certain sequence, then putting the substrates into a vacuum bag for vacuumizing and sealing, and then pressing and fusing the substrate aggregate placed in the vacuum bag at high temperature to form a laminated body;

(3) cutting: placing the laminated body in punching equipment, and cutting the laminated body into a battery blank with a specified design appearance;

(4) and (3) sintering: sintering the battery blank in a high-temperature furnace at a proper heat treatment temperature, wherein the sintered battery blank shrinks the size and becomes a battery with higher strength, and meanwhile, a regular and uniform embedded air passage is left in an inner electrode of the battery due to the gasification escape of an air passage precursor in the heat treatment process;

(5) and (3) firing the middle layer: preparing an intermediate layer on the electrolytes on both sides of the battery after firing through high-temperature heat treatment;

(6) reduction: the battery sintered by the middle layer is placed in a reducing furnace for reduction, and the nickel oxide in the inner electrode is reduced into metallic nickel;

(7) preparing an outer surface part: printing an outer surface part on the outer surface of the reduced battery;

(8) preparing a side sealing component: for the battery preparation side seal component which completes the process, firstly preparing a rough and breathable side seal inner layer, and continuously preparing a compact and airtight side seal outer layer on the side seal inner layer after the side seal inner layer is dried;

(9) and (3) heat treatment: carrying out heat treatment on the battery after the printing of the outer surface parts and the preparation of the side sealing member are finished, wherein after the heat treatment, each outer surface part and the attachment of the outer surface part form firm connection, and at least one layer of the side sealing member is densified;

(10) and (5) strengthening the electrode.