A flat plate type solid oxide electrolytic cell sealing component and its application

Abstract

The present invention relates to the technical field of solid oxide electrolytic cells, and in particular to a flat solid oxide electrolytic cell sealing assembly and its application. The sealing assembly comprises a first sealing component, a second sealing component, an electrolytic cell and a metal bipolar plate, wherein the edges of the electrolytic cell are surrounded by the first sealing component to form an electrolytic cell with a sealing frame; the second sealing component and the electrolytic cell with the sealing frame are both arranged on the metal bipolar plate, and the second sealing component is located on the outside of the electrolytic cell with the sealing frame to form a stack assembly repeating unit, and the second sealing component is used for sealing between two stacked stack assembly repeating units. The present invention can simultaneously form an effective seal after the stack assembly is heated, avoiding the problem of connector oxidation caused by the pre-sealing of the electrolytic cell and the connector, and the method is simple, easy to operate, flexible and efficient.

Description

Technical Field

[0001] The invention relates to the technical field of solid oxide electrolytic cells, and in particular to a flat-plate solid oxide electrolytic cell sealing component and application thereof. Background Art

[0002] Solid Oxide Electrolysis Cell (SOEC) is an energy conversion device that converts electrical energy into chemical energy, with outstanding advantages such as cleanliness and efficiency. Developing SOEC efficient green hydrogen production technology is an effective way to achieve the goals of "carbon peak" and "carbon neutrality". Although great progress has been made in materials, components and integration technology in recent years, the high temperature (600-1000℃) and high humidity (AR>80%) working environment of SOEC limits the development and application of sealing materials and sealing technology.

[0003] Glass and glass-ceramics are the most widely studied and applied sealing materials. s ) above, softening flow occurs to achieve infiltration of the sealing part, and the temperature is reduced to T s The following solidification occurs to achieve sealing. Compared with other forms of sealing materials such as flexible metal, mica substrate, metal brazing, etc., glass has significant advantages such as good high-temperature sealing performance, adjustable coefficient of expansion (CTE), and easy preparation and use. There are currently two commonly used sealing methods: one is to directly apply the sealing slurry to the metal bipolar plate to be sealed during the battery assembly process, place the electrolytic cell, and then stack it layer by layer. This sealing scheme is simple and easy to implement, but in the implementation process, placing the electrolytic cell on the flowing sealing slurry makes it difficult to accurately position it, and may cause problems such as dislocation and displacement after pressurization; in addition, excessive flow of the slurry may block the water vapor inlet and outlet channels, resulting in uneven water vapor distribution. Another sealing method is to pre-seal the electrolytic cell to the battery frame with glass sealant before the battery stack is assembled, and then seal the battery frame and the metal bipolar plate when the battery stack is assembled. This sealing scheme uses glass for pre-sealing. During the later pressurization process of the battery stack assembly, stress concentration is likely to occur at the edge of the electrolytic cell, causing damage to the cell; in addition, the use of the battery frame increases the sealing surface, thereby increasing the gas leakage channel. Therefore, under the premise of overcoming the excessive flow of glass slurry during use and avoiding stress concentration caused by pre-sealing, making full use of the good sealing properties of glass and seeking a sealing solution that is simple to operate and has reliable performance has become an urgent problem to be solved by technical personnel in this field. Summary of the invention

[0004] In view of the above problems, the object of the present invention is to provide a flat-plate solid oxide electrolytic cell sealing assembly and its application to improve the sealing performance of the electrolytic cell.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] The present invention provides a flat solid oxide electrolytic cell sealing assembly, comprising a first sealing component, a second sealing component, an electrolytic cell and a metal bipolar plate, wherein the first sealing component is encapsulated around the edges of the electrolytic cell to form an electrolytic cell with a sealing frame;

[0007] The second sealing component and the electrolytic cell with a sealing frame are both arranged on the metal bipolar plate, and the second sealing component is located on the outside of the electrolytic cell with a sealing frame to form a battery stack assembly repeating unit. The second sealing component is used for sealing between two stacked battery stack assembly repeating units.

[0008] The first sealing component is a multi-layer structure and is sealed at the upper edge, side edge and lower edge of the electrolytic cell by gluing.

[0009] The base material of the first sealing component is glass fiber mat.

[0010] The base material of the first sealing member further contains glass powder or ceramic powder.

[0011] The electrolytic cell is composed of a first electrode, an electrolyte, and a second electrode, wherein the first electrode is exposed to the inner side of the first sealing component.

[0012] The upper and lower sides of the metal bipolar plate are provided with sealing grooves, limiting steps and gas flow channels. The limiting steps are used to limit the electrolytic cell with a sealing frame. The sealing groove is located outside the limiting steps and is used to fix the second sealing component.

[0013] The second sealing component has a shape and size that are compatible with the metal bipolar plate, and the second sealing component also has openings corresponding to the air channel and the common air channel area of ​​the electrolytic cell.

[0014] The material of the second sealing component is any one of glass, glass-ceramic and mica, and the structural form can be any one of felt, gasket and slurry coating.

[0015] An application of the above-mentioned planar solid oxide electrolytic cell sealing assembly comprises the following steps:

[0016] Step 1: the first sealing component is adhered to the upper edge, lower edge and side edge of the electrolytic cell by an adhesive to form an electrolytic cell with a sealed frame;

[0017] Step 2, stacking in sequence: lower end plate, lower insulating plate, lower current collecting plate, metal bipolar plate, electrolytic cell with sealing frame, second sealing component, metal bipolar plate, electrolytic cell with sealing frame, second sealing component ... upper current collecting plate, upper insulating plate, upper end plate;

[0018] Step 3: Apply a compressive force to the upper end plate and the lower end plate, and use screws to penetrate the stacked components in sequence to fix them;

[0019] Step 4: Place the electrolytic cell stack in a high temperature furnace and heat it to above the glass softening temperature of the first sealing component to seal the electrolytic cell stack.

[0020] The glass softening temperature of the first sealing component is 30-50° C. higher than the working temperature of the electrolytic cell stack.

[0021] The advantages and beneficial effects of the present invention are:

[0022] 1. Before assembling the battery stack, the present invention adheres the first sealing component around the electrolytic cell to form an electrolytic cell with a sealing frame. During the assembly of the battery stack, the electrolytic cell with the sealing frame is placed in the corresponding area on the bipolar plate, and the position of the electrolytic cell is limited by the step. After the battery stack is assembled, the temperature is raised to above the softening temperature of the sealing component to achieve softening sealing. Since the base material of the first sealing component is glass, this sealing form can not only utilize the excellent sealing performance of glass, but also avoid excessive flow of glass slurry during use and stress concentration during pre-sealing.

[0023] 2. The first sealing component and the second sealing component are used to seal between the single cell and the connector, and between the connectors, respectively, and can be designed according to actual needs. At the same time, after the temperature of the battery stack is raised, an effective seal can be formed between the single cell and the connector, and between the connectors, to avoid the oxidation problem of the connector caused by the pre-sealing of the single cell and the connector. The method is simple, easy to implement, flexible and efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic structural diagram of a sealing assembly of a flat-plate solid oxide electrolytic cell in Example 1 of the present invention;

[0025] Figure 2 It is a schematic structural diagram of an electrolytic cell with a sealed frame in Example 1 of the present invention;

[0026] Figure 3 is a schematic structural diagram of the second sealing component in Example 1 of the present invention;

[0027] Figure 4 This is a schematic diagram of the battery stack assembly in Example 1 of the present invention;

[0028] Figure 5 It is a schematic diagram of the structure of an electrolytic cell with a sealed frame in Example 2 of the present invention;

[0029] Figure 6 It is a schematic diagram of the assembly of the first sealing component and the electrolytic cell in Example 2 of the present invention;

[0030] Figure 7 is a schematic structural diagram of the second sealing component in Example 2 of the present invention;

[0031] Figure 8 It is a schematic diagram of the structure of an electrolytic cell with a sealed frame in Example 3 of the present invention;

[0032] In the figure: 1-electrolysis cell, 2-first electrode, 3-electrolyte, 4-second electrode, 5-first sealing component, 5(a)-upper seal, 5(b)-middle seal, 5(c)-lower seal, 6-first metal bipolar plate, 7-second metal bipolar plate, 8-gas flow channel, 9-limiting step, 10-lower end plate, 11-lower insulating plate, 12-lower current collecting plate, 13-electrolysis cell with sealing frame, 14-second sealing component, 15-stack assembly repeating unit, 16-upper current collecting plate, 17-upper insulating plate, 18-upper end plate. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] like Figure 1 As shown, a flat-plate solid oxide electrolytic cell sealing assembly provided by the present invention includes a first sealing component 5, a second sealing component 14, an electrolytic cell 1 and a metal bipolar plate, wherein the first sealing component 5 is encapsulated on all four edges of the electrolytic cell 1 to form an electrolytic cell 13 with a sealing frame; the second sealing component 14 and the electrolytic cell 13 with a sealing frame are both arranged on the metal bipolar plate, and the second sealing component 14 is located on the outside of the electrolytic cell 13 with a sealing frame to form a stack assembly repeating unit 15, and the second sealing component 14 is used for sealing between two stacked groups of stack assembly repeating units 15.

[0035] like Figure 2 As shown, in the embodiment of the present invention, the first sealing component 5 is a multi-layer structure, and the multi-layer structure is pasted on the upper edge, side edge and lower edge of the electrolytic cell 1 by pasting to form an electrolytic cell 13 with a sealed frame.

[0036] Specifically, the base material of the first sealing component 5 is glass fiber felt, which is located at the periphery of the electrolytic cell 1 and is pre-pasted to the upper edge, lower edge and side edge of the electrolytic cell 1 by lamination before the battery stack is assembled, thereby forming an electrolytic cell 13 with a sealed frame.

[0037] Furthermore, the base material of the first sealing component 5 also contains glass powder or ceramic powder. The softening temperature of the glass of the first sealing component 5 is 30-50° C. higher than the working temperature of the electrolytic cell stack.

[0038] In the embodiment of the present invention, the electrolytic cell 1 is composed of a first electrode 2, an electrolyte 3 and a second electrode 4, wherein the first electrode 2 is exposed to the inner side of the first sealing component 5. Specifically, the first sealing component 5 is provided with an opening that matches the electrode region of the electrolytic cell, and the size of the opening is larger than the size of the first electrode 2 and smaller than the size of the electrolyte 3.

[0039] like Figure 1 As shown, in an embodiment of the present invention, sealing grooves, limiting steps 9 and gas flow channels 8 are provided on the upper and lower sides of the metal bipolar plate. The limiting steps 9 are used to limit the electrolytic cell 13 with a sealing frame. The sealing groove is located on the outer side of the limiting step 9 and is used to fix the second sealing component 14.

[0040] Specifically, the second sealing component 14 is located between the first metal bipolar plate 6 and the second metal bipolar plate 7. Figure 3 As shown, in the embodiment of the present invention, the second sealing component 14 has a shape and size that are compatible with the metal bipolar plate, and the second sealing component 14 also has openings corresponding to the airway and common airway areas of the electrolytic cell 1.

[0041] Specifically, the material of the second sealing component 14 is any one of glass, glass-ceramic and mica, and the structural form can be any one of felt, gasket and slurry coating.

[0042] In the present invention, before assembling the battery stack, the first sealing component 5 is pasted around the electrolytic cell 1 to form an electrolytic cell 13 with a sealing frame. During the assembly of the battery stack, the electrolytic cell 13 with a sealing frame is placed in the corresponding area of ​​the metal bipolar plate, and the position of the electrolytic cell 13 with a sealing frame is limited by the limiting step 9. After the battery stack is assembled, the temperature is raised to above the softening temperature of the first sealing component 5 to achieve softening sealing. Since the base material of the first sealing component 5 is glass, this sealing form can not only utilize the excellent sealing performance of glass, but also avoid excessive flow of glass slurry during use and stress concentration during pre-sealing.

[0043] Based on the above design concept, another embodiment of the present invention provides an application of the above-mentioned flat-plate solid oxide electrolytic cell sealing assembly, such as Figure 4 As shown, the application includes the following steps:

[0044] Step 1: The first sealing component 5 is adhered to the upper edge, the lower edge and the side edge of the electrolytic cell 1 by means of an adhesive to form an electrolytic cell 13 with a sealed frame;

[0045] Step 2: stacking in sequence: lower end plate 10, lower insulating plate 11, lower current collecting plate 12, metal bipolar plate, electrolytic cell 13 with sealing frame, second sealing component 14, metal bipolar plate, electrolytic cell 13 with sealing frame, second sealing component 14 ... upper current collecting plate 16, upper insulating plate 17, upper end plate 18;

[0046] Step 3: Apply a compressive force to the upper end plate 18 and the lower end plate 10, and use screws to penetrate the stacked components in sequence to fix them;

[0047] Step 4: Place the electrolytic cell stack in a high temperature furnace and heat it to above the glass softening temperature of the first sealing component 5 to seal the electrolytic cell stack.

[0048] Preferably, the glass softening temperature of the first sealing member 5 is 30-50° C. higher than the operating temperature of the electrolytic cell stack.

[0049] Another embodiment of the present invention provides an application of a flat solid oxide electrolytic cell sealing assembly, wherein the electrolytic cell and the connector, and the connectors are sealed with a first sealing component and a second sealing component, respectively, and can be designed according to actual needs. At the same time, after the temperature of the battery stack is raised, an effective seal can be formed between the electrolytic cell and the connector, and between the connectors, to avoid the connector oxidation problem caused by the pre-sealing of the electrolytic cell and the connector. The method is simple, easy to implement, flexible and efficient.

[0050] Example 1

[0051] like Figure 1-4 As shown, the present invention provides a flat-plate solid oxide electrolytic cell sealing assembly, a first sealing component 5, a second sealing component 14, an electrolytic cell 1 and a metal bipolar plate, wherein the electrolytic cell is flat-plate-type, and the first sealing component 5 is used for sealing the flat-plate electrolytic cell 1. The electrolytic cell 1 is composed of a first electrode 2, an electrolyte 3, and a second electrode 4. The first sealing component 5 comprises an upper seal 5 (a), a middle seal 5 (b) and a lower seal 5 (c), which are composed of three layers, and the base materials are all glass fiber felt, which are adhered to the upper edge, side edge and lower edge of the electrolytic cell 1 in a stacked manner to form an electrolytic cell 13 with a sealing frame. The first sealing component 5 is provided with an opening that matches the electrode area of ​​the electrolytic cell, and the size of the opening is larger than the size of the first electrode 2 and smaller than the size of the electrolyte 3. As Figure 3 and Figure 4As shown, the second sealing component 14 is made of mica pad, located between the first metal bipolar plate 6 and the second metal bipolar plate 7, with a shape and size matching those of the metal bipolar plate, and is provided with openings corresponding to the electrolytic cell area and the common airway area.

[0052] An application of a flat-plate solid oxide electrolytic cell sealing assembly comprises the following steps:

[0053] Step 1: The upper seal 5 (a), the middle seal 5 (b) and the lower seal 5 (c) of the first sealing component 5 are respectively adhered to the upper edge, the side edge and the lower edge of the electrolytic cell 1 by an adhesive to form an electrolytic cell 13 with a sealed frame;

[0054] Step 2: stacking in order of lower end plate 10, lower insulating plate 11, lower current collecting plate 12, metal bipolar plate 7, electrolytic cell with sealing frame 13, second sealing component 14, metal bipolar plate 7 ... upper current collecting plate 16, upper insulating plate 17, upper end plate 18;

[0055] Step 3: Apply a compressive force to the upper end plate 18 and the lower end plate 10, and fix them with screws;

[0056] Step 4: Place the electrolytic cell stack in a high temperature furnace and heat it to above the glass softening temperature of the first sealing component 5 to seal the electrolytic cell stack.

[0057] Among them, the first metal bipolar plate 6 and the second metal bipolar plate 7 are provided with a limiting step 9 corresponding to the first sealing component 5, and the limiting step 9 is used in conjunction with the electrolytic cell 13 with a sealing frame; the lower edge size of the limiting step 9 is larger than the size of the first electrode 2 and smaller than the size of the electrolyte 3. A sealing groove is also provided on the metal bipolar plate, which is used in conjunction with the second sealing component 14. The first metal bipolar plate 6 and the second metal bipolar plate 7 are sealed by the second sealing component 14.

[0058] Example 2

[0059] Different from the first embodiment, the first sealing member 5 in this embodiment is composed of two layers: an upper sealing layer 5 (a) and a lower sealing layer 5 (b). Figure 5 and 6 As shown. The upper seal 5 (a) and the lower seal 5 (b) are symmetrically arranged, and the cross section is L-shaped. In addition, in this embodiment, the second sealing component 14 is also made of glass fiber felt, the shape and size match the metal bipolar plate, and is provided with openings corresponding to the electrolytic cell area and the public airway area, such as Figure 7 shown.

[0060] Example 3

[0061] Different from the first embodiment, the first sealing member 5 in this embodiment is composed of two layers: an upper sealing layer 5 (a) and a lower sealing layer 5 (b). Figure 8 Specifically, the upper seal 5 (a) is a flat plate structure, and the cross section of the lower seal 5 (b) is an L-shaped structure. In addition to the glass fiber felt matrix material, the first sealing component 5 also contains glass powder.

[0062] The present invention provides a flat-plate solid oxide electrolytic cell sealing component and its application, which can not only utilize the excellent sealing performance of glass, but also avoid excessive flow of glass slurry during use and stress concentration during pre-sealing, and also avoid the connector oxidation problem caused by pre-sealing of the electrolytic cell and the connector.

[0063] The above description is only an embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, expansion, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims

1. A flat plate solid oxide electrolytic cell sealing assembly, characterized in that: It comprises a first sealing component, a second sealing component, an electrolytic cell and a metal bipolar plate, wherein the first sealing component is encapsulated around the edges of the electrolytic cell to form an electrolytic cell with a sealing frame; The second sealing component and the electrolytic cell with a sealing frame are both arranged on the metal bipolar plate, and the second sealing component is located outside the electrolytic cell with a sealing frame to form a stack assembly repeating unit, and the second sealing component is used for sealing between two stack assembly repeating units; The upper and lower sides of the metal bipolar plate are provided with sealing grooves, limiting steps and gas flow channels. The limiting steps are used to limit the electrolytic cell with a sealing frame. The sealing groove is located outside the limiting steps and is used to fix the second sealing component.

2. The planar solid oxide electrolytic cell sealing assembly according to claim 1, characterized in that: The first sealing component is a multi-layer structure and is sealed at the upper edge, side edge and lower edge of the electrolytic cell by gluing.

3. The sealing assembly of a planar solid oxide electrolytic cell according to claim 2, characterized in that: The base material of the first sealing component is glass fiber mat.

4. The sealing assembly of a planar solid oxide electrolytic cell according to claim 3, characterized in that: The base material of the first sealing member further contains glass powder or ceramic powder.

5. The planar solid oxide electrolytic cell sealing assembly according to claim 1, characterized in that: The electrolytic cell is composed of a first electrode, an electrolyte, and a second electrode, wherein the first electrode is exposed to the inner side of the first sealing component.

6. The sealing assembly of a planar solid oxide electrolytic cell according to claim 1, characterized in that: The second sealing component has a shape and size that are compatible with the metal bipolar plate, and the second sealing component also has openings corresponding to the air channel and the common air channel area of ​​the electrolytic cell.

7. The planar solid oxide electrolytic cell sealing assembly according to claim 1, characterized in that: The material of the second sealing component is any one of glass, glass-ceramic and mica, and the structural form is any one of felt, gasket and slurry coating.

8. An application of the flat-plate solid oxide electrolytic cell sealing assembly according to any one of claims 1 to 7, characterized in that: The application comprises the following steps: Step 1: the first sealing component is adhered to the upper edge, lower edge and side edge of the electrolytic cell by an adhesive to form an electrolytic cell with a sealed frame; Step 2, stacking in sequence: lower end plate, lower insulating plate, lower current collecting plate, metal bipolar plate, electrolytic cell with sealing frame, second sealing component, metal bipolar plate, electrolytic cell with sealing frame, second sealing component ... upper current collecting plate, upper insulating plate, upper end plate; Step 3: Apply a compressive force to the upper end plate and the lower end plate, and use screws to penetrate the stacked components in sequence to fix them; Step 4: Place the electrolytic cell stack in a high temperature furnace and heat it to above the glass softening temperature of the first sealing component to seal the electrolytic cell stack.

9. The use of the sealing assembly for a planar solid oxide electrolytic cell according to claim 8, characterized in that: The glass softening temperature of the first sealing component is 30-50° C. higher than the working temperature of the electrolytic cell stack.

Images