A tubular SOFC cell, a tubular SOFC assembly and a SOFC stack

Abstract

This invention provides a tubular SOFC battery, a tubular SOFC module, and an SOFC stack, belonging to the field of fuel cell technology. The tubular SOFC battery includes an anode support tube, which has at least two electrolyte layers spaced apart by conductive ceramic layers. Along the axial length of the anode support tube, except for the two ends of the electrolyte layers, a barrier layer is formed on the remaining portion. A cathode layer is formed on the barrier layer. The tubular SOFC module includes a tubular SOFC battery and a first metal connector. The SOFC stack includes the tubular SOFC module. In this invention, the tubular SOFC battery adopts a spaced electrode design, reducing the axial resistance of the battery tube while ensuring the integrity of the battery tube support structure. The first metal connector shortens the current conduction path by 2 / 3, significantly reducing internal current loss caused by the internal resistance of the battery substrate and improving the power generation efficiency after assembly into a stack.

Description

Technical Field

[0001] This utility model relates to the field of fuel cell technology, and in particular to a tubular SOFC battery, a tubular SOFC module, and an SOFC stack. Background Technology

[0002] Solid oxide fuel cells (SOFCs), as a highly efficient and low-pollution energy conversion device, have attracted widespread research and application.

[0003] Due to its structural characteristics, the anode and cathode of a tubular SOFC are located on the inner and outer sides of the tubular structure, respectively. Since tubular SOFCs are generally designed for miniaturized applications, their diameter is typically less than 1 cm. Furthermore, during operation, the inner and outer sides of the tubular SOFC come into contact with either the fuel gas or the oxidant. Therefore, the power extraction design of the battery tubes and the multi-tube series connection scheme have a significant impact on the actual performance of the stack (maximum power, power generation efficiency, operational life, etc.).

[0004] Therefore, it is urgent to redesign the power supply of the battery to ensure the integrity of the gas seal of the battery tube and reduce the axial resistance of the battery tube caused by the large length-to-diameter ratio. Utility Model Content

[0005] This invention aims to provide a tubular SOFC battery, a tubular SOFC module, and an SOFC stack. The tubular SOFC battery adopts an interleaved electrode design, which reduces the axial resistance of the battery tube while ensuring the integrity of the battery tube support structure. At the same time, since the power extraction design does not change the axisymmetric structure of the battery tube, the thermal shock resistance of the tubular SOFC battery is not significantly weakened, and the stack can better adapt to the rapid heating and cooling requirements in actual use. In the tubular SOFC module, the current conduction path is shortened by 2 / 3, which can significantly reduce the internal current loss caused by the internal resistance of the battery substrate and improve the power generation efficiency after assembly into a stack. The SOFC stack can be flexibly designed according to actual needs, which facilitates the design of solid oxide fuel cell stacks of different specifications and realizes high-power structural modules of the stack.

[0006] The technical solution adopted in this utility model is: A tubular SOFC battery includes an anode support tube, on the outer peripheral wall of the anode support tube at least two electrolyte layers spaced apart along its axial length, with adjacent electrolyte layers separated by conductive ceramic layers; along the axial length of the anode support tube, except for the two ends along the length direction of the electrolyte layers, a barrier layer is formed on the remaining portion of each electrolyte layer; a cathode layer is formed on the barrier layer.

[0007] Furthermore, the length of the electrolyte layer is greater than the length of the conductive ceramic layer; And / or, the length of the cathode layer is less than or equal to the length of the barrier layer.

[0008] Furthermore, the anode support tube is formed with three electrolyte layers and two conductive ceramic layers at intervals.

[0009] Based on the same inventive concept, the present invention also provides a tubular SOFC assembly, including at least two tubular SOFC cells as described above, and a first metal connector, a second metal connector, and a third metal connector; the first metal connector includes a first metal strip body, on which the first metal strip body has a first anode-side metal connector and a first cathode-side metal connector respectively corresponding to the cathode layer and the conductive ceramic layer; the first anode-side metal connector of the same first metal connector corresponds to the conductive ceramic layer on one of the tubular SOFC cells, and the first cathode-side metal connector of the same first metal connector corresponds to the conductive ceramic layer on the other tubular SOFC cell. The cathode layer is connected to realize a series circuit structure between the corresponding tubular SOFC cells; the second metal connector includes a second metal strip body, and the second metal strip body has a second anode-side metal connector that matches the number and position of the conductive ceramic layers; the third metal connector includes a third metal strip body, and the third metal strip body has a third cathode-side metal connector that matches the number and position of the cathode layers; the second anode-side metal connector is connected to the conductive ceramic layer of the tubular SOFC cell at the beginning of the series circuit structure, and the third cathode-side metal connector is connected to the cathode layer of the tubular SOFC cell at the end of the series circuit structure.

[0010] Furthermore, the first anode-side metal connector and the second anode-side metal connector are in the shape of an arc plate, the radius of which is the same as the outer radius of the corresponding conductive ceramic layer on the tubular SOFC battery, and the length of which is less than the length of the corresponding conductive ceramic layer. And / or, the first cathode-side metal connector and the third cathode-side metal connector are in the shape of an arc plate, the radius of which is the same as the outer radius of the corresponding cathode layer on the tubular SOFC battery, and the length of which is less than the length of the corresponding cathode layer.

[0011] Furthermore, the first anode-side metal connector and / or the second anode-side metal connector are semi-circular shell-shaped; And / or, the first anode-side metal connector and the second anode-side metal connector adopt a double-layer metal structure, and the coefficient of thermal expansion of the outer metal layer is greater than that of the inner metal layer; And / or, the first cathode-side metal connector and / or the third cathode-side metal connector are in the shape of a 1 / 4 circular shell.

[0012] Based on the same inventive concept, the present invention also provides an SOFC stack, including the aforementioned tubular SOFC assembly and two stack mounting plates; the stack mounting plates have mounting through holes with the same number as the tubular SOFC cells, and the diameter of the mounting through holes is adapted to the outer diameter of both ends of the tubular SOFC cells; the two stack mounting plates are arranged in parallel, and both ends of the tubular SOFC cells are inserted into the corresponding mounting through holes and sealed with ceramic adhesive.

[0013] Furthermore, the mounting through hole is a stepped hole with axial center coincidence, the diameter of the larger section is adapted to the outer diameter of both ends of the tubular SOFC battery, and the diameter of the smaller section is smaller than the inner diameter of the tubular SOFC battery. And / or, tensioning components are also provided on the opposite sides of the two stack fixing plates.

[0014] Furthermore, an inlet / outlet diffuser compartment is provided on the outer side of the fuel cell stack mounting plate; the side of the inlet / outlet diffuser compartment facing the fuel cell stack mounting plate is open and covers all the mounting through holes; an inlet / outlet pipe is also provided on the inlet / outlet diffuser compartment, and the axial length direction of the inlet / outlet pipe is perpendicular to the axial length direction of the tubular SOFC battery.

[0015] Furthermore, the inlet and outlet gas diffusion end chamber is a hollow trapezoidal platform, with its larger open side facing the fuel cell stack fixing plate; And / or, the inlet / outlet pipe further includes an end-closed extension extending along its axial length into the inlet / outlet diffuser chamber, the extension having an air hole, the opening direction of the air hole being perpendicular to the axial length direction of the tubular SOFC battery.

[0016] The beneficial effects of this utility model are: 1. To address a series of problems such as difficulty in extracting power from the inner wall of a circular tube, the disruption of the structural integrity of the tube due to the power extraction design, and excessive internal losses caused by excessively long power extraction paths, the tubular SOFC battery of this invention adopts an interleaved electrode design. This reduces the axial resistance of the battery tube while ensuring the integrity of the battery tube support structure. Simultaneously, since the power extraction design does not alter the axisymmetric structure of the battery tube, the thermal shock resistance of the tubular SOFC battery is not significantly weakened, allowing for better adaptation to the rapid temperature rise and fall requirements of actual use when assembled into a battery stack.

[0017] 2. Compared to the traditional series connection of batteries with the anode and cathode connected end-to-end, the tubular SOFC module in this invention, based on the first metal connector, can shorten the current conduction path by 2 / 3, significantly reducing internal current loss caused by the internal resistance of the battery substrate and improving the power generation efficiency after assembly into a stack. The independent first metal connector design not only simplifies the stack assembly stage but also facilitates maintenance when the stack unit is damaged, improving the maintainability of the stack. The second and third metal connectors can adopt a double-connector design, allowing for more precise inspection and analysis of the stack through a four-wire, two-electrode scheme during actual operation.

[0018] 3. The SOFC stack in this utility model can be flexibly designed according to actual needs, which facilitates the design of solid oxide fuel cell stacks of different specifications and realizes high-power stack structure modules. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a front view of the tubular SOFC battery in Example 1.

[0021] Figure 2 This is a three-dimensional structural diagram of the tubular SOFC battery in Example 1.

[0022] Figure 3 This is a three-dimensional structural diagram of the tubular SOFC component in Example 2.

[0023] Figure 4 This is a left view of the tubular SOFC assembly in Example 2.

[0024] Figure 5 This is a three-dimensional structural diagram of the first metal connector in Example 2.

[0025] Figure 6 This is a three-dimensional structural diagram of the SOFC stack in Example 3.

[0026] Figure 7 This is a three-dimensional structural diagram of the SOFC stack in Example 3, excluding the tubular SOFC assembly.

[0027] Figure 8 This is a three-dimensional structural diagram of the inlet and outlet gas diffusion chamber in Example 3.

[0028] The attached figures are labeled as follows: 100. Tubular SOFC battery; 110. Anode support tube; 120. Electrolyte layer; 130. Conductive ceramic layer; 140. Cathode layer; 200, First metal connector; 210, First metal strip body; 220, First anode-side metal connector; 230, First cathode-side metal connector; 300. Second metal connector; 310. Second metal strip body; 320. Second anode-side metal connector; 400. Third metal connector; 410. Third metal strip body; 420. Third cathode-side metal connector; 500. Fuel cell stack mounting plate; 510. Mounting through hole; 600. Inlet / outlet diffuser compartment; 610. Inlet / outlet pipe; 620. Extension section; 630. Air vent; 700, tensioning assembly; 710, bolt; 720, spring; 730, washer; 740, nut. Detailed Implementation

[0029] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0030] The following disclosure provides many different embodiments or examples for implementing various structures of this invention. To simplify the disclosure, specific examples of components and arrangements are described below. Of course, these are merely examples and are not intended to limit the scope of this invention.

[0031] The embodiments of the utility model will now be described in detail with reference to the accompanying drawings.

[0032] Example 1

[0033] Figure 1 This is a front view of the tubular SOFC battery in Example 1. Figure 2 This is a three-dimensional structural diagram of the tubular SOFC battery in Example 1. Figure 1 and Figure 2As shown, the tubular SOFC battery 100 includes an anode support tube 110. The anode support tube 110 is made of 8YSZ or 3YSZ mixed with NiO. It serves as the anode of the battery and is also the thickest structural layer of the entire battery. The rest of the battery structure is fabricated on the anode support tube 110. Specifically, at least one tubular electrolyte layer 120, a tubular conductive ceramic layer 130, and another tubular electrolyte layer 120 are sequentially formed along the axial length of the outer peripheral wall of the anode support tube 110. That is, at least two electrolyte layers 120 are formed at intervals on the anode support tube 110, with adjacent electrolyte layers 120 separated by conductive ceramic layers 130. In other words, the entire anode support tube 110 is covered by electrolyte layers 120 and conductive ceramic layers 130. The electrolyte layer 120 is made of 8YSZ material, and the conductive ceramic layer 130 is made of strontium titanate conductive ceramic material to achieve gas sealing and current conduction. Along the axial length of the anode support tube 110, the length of the electrolyte layer 120 is much greater than the length of the conductive ceramic layer 130. Furthermore, except for the two ends of the tubular SOFC battery 100 along its length, a tubular barrier layer is formed on the remaining portion of each electrolyte layer 120. The length of the barrier layer is less than the length of the corresponding electrolyte layer 120, and the barrier layer is composed of GDC (Gas Dioxide, Gas Dioxide, and Carbon Dioxide). Meanwhile, a tubular cathode layer 140 is formed on the barrier layer. The cathode layer is composed of LSCF and GDC, etc. The length of the cathode layer 140 is less than or equal to the length of the barrier layer, and the total thickness of the cathode layer 140, the barrier layer and the electrolyte layer 120 is equal to or slightly less than the thickness of the conductive ceramic layer 130.

[0034] like Figure 1 and Figure 2 As shown, taking a 15 cm long tubular SOFC battery 100 as an example, an electrolyte layer 120, a conductive ceramic layer 130, another electrolyte layer 120, a conductive ceramic layer 130, and another electrolyte layer 120 are sequentially formed along the axial length of the outer peripheral wall of the anode support tube 110. The lengths of the electrolyte layers 120 at both ends are 48 mm, the length of the middle electrolyte layer 120 is 46 mm, and the length of the conductive ceramic layers 130 is 4 mm. A 5 mm area is left at the end of the electrolyte layer 120 at the anode support tube 110 as a sealing connection area for the gas inlet and outlet positions when subsequently assembled into an SOFC stack. The lengths of the barrier layer and the cathode layer 140 are both 40 mm. That is, the tubular SOFC battery includes two sealed connection areas A (5 mm in length, consisting of an anode support tube 110 and an electrolyte layer 120), four transition areas B (3 mm in length, consisting of an anode support tube 110 and an electrolyte layer 120), three cathode areas C (40 mm in length, consisting of an anode support tube 110, an electrolyte layer 120, a barrier layer, and a cathode layer 140), and two anode areas D (4 mm in length, consisting of an anode support tube 110 and a conductive ceramic layer 130).

[0035] To address a series of issues in existing tubular SOFC batteries, such as difficulties in power extraction from the inner wall of the cylindrical tube, the disruption of the tube's structural integrity due to the power extraction design, and excessive internal losses caused by excessively long power extraction paths, this embodiment employs a spaced electrode design in the tubular SOFC battery. This design reduces the axial resistance of the battery tube while ensuring the integrity of the battery tube's supporting structure. Furthermore, since the power extraction design does not alter the axisymmetric structure of the battery tube, the thermal shock resistance of the tubular SOFC battery is not significantly weakened, allowing it to be better adapted to the rapid temperature rise and fall requirements of actual use when assembled into a battery stack.

[0036] Example 2

[0037] Figure 3 This is a schematic diagram of the tubular SOFC component in Example 2. Figure 4 This is a left view of the tubular SOFC assembly in Example 2. Figure 3 and Figure 4 As shown, the tubular SOFC assembly includes at least two tubular SOFC cells 100 shown in Embodiment 1, a first metal connector 200, a second metal connector 300, and a third metal connector 400. Figure 5 This is a three-dimensional structural schematic diagram of the first metal connector in Example 2. Figures 3-5As shown, the first metal connector 200 includes a flat first metal strip body 210, the length of which is less than the length of the tubular SOFC battery 100. A first anode-side metal connector 220, matching the number and position of the conductive ceramic layers 130, is formed on the first metal connector 200. The first anode-side metal connector 220 is connected to a corresponding conductive ceramic layer 130 on one tubular SOFC battery 100 via conductive adhesive or the like. Simultaneously, a first cathode-side metal connector 230, matching the number and position of the cathode layers 140, is also formed on the first metal connector 200. The first cathode-side metal connector 230 is connected to a corresponding cathode layer 140 on another tubular SOFC battery 100 via conductive adhesive or the like. Thus, multiple tubular SOFC batteries 100 and corresponding first metal connectors 200 cooperate to form a series circuit structure; wherein, the conductive ceramic layer 130 of the tubular SOFC battery 100 at the beginning of the series circuit structure and the cathode layer 140 of the tubular SOFC battery 100 at the end of the series circuit structure are used for positive and negative electrode leads. The second metal connector 300 has a similar structure to the first metal connector 200, and includes a flat second metal strip body 310; the length of the second metal strip body 310 is greater than the length of the tubular SOFC battery 100, and its two ends can serve as negative electrode terminals; the second metal strip body 310 is formed with second anode-side metal connectors 320 that match the number and position of the conductive ceramic layers 130, and the second anode-side metal connectors 320 are connected to the conductive ceramic layer 130 of the tubular SOFC battery 100 at the beginning of the series circuit structure by conductive adhesive or the like. The third metal connector 400 is similar in structure to the first metal connector 200, and includes a flat third metal strip body 410. The length of the third metal strip body 410 is greater than the length of the tubular SOFC battery 100, and its two ends can be used as positive terminals. The third metal strip body 410 is formed with third cathode-side metal connectors 420 that match the number and position of the cathode layers 140. The third cathode-side metal connectors 420 and the cathode layers 140 of the tubular SOFC battery 100 at the end of the series circuit structure are connected together by conductive adhesive or the like.

[0038] like Figure 3 and Figure 4As shown, the tubular SOFC module uses a total of 25 tubular SOFC cells 100, arranged in a horizontal and vertical configuration of 5 cells each. Each tubular SOFC cell 100 includes two sealed connection areas A (5 mm in length, consisting of an anode support tube 110 and an electrolyte layer 120), four transition areas B (3 mm in length, consisting of an anode support tube 110 and an electrolyte layer 120), three cathode areas C (40 mm in length, consisting of an anode support tube 110, an electrolyte layer 120, a barrier layer, and a cathode layer 140), and two anode areas D (4 mm in length, consisting of an anode support tube 110 and a ceramic conductive layer). Each first metal connector 200 includes two first anode-side metal connectors 220 and three first cathode-side metal connectors 230. When assembled, adjacent tubular SOFC batteries 100 in the 25 tubular SOFC batteries 100 are connected in series through 24 first metal connectors 200. For example, the cathode layer 140 of tubular SOFC battery 1# is connected to the first cathode side metal connector 230 of first metal connector 1#; the conductive ceramic layer 130 of tubular SOFC battery 1# is connected to the first anode side metal connector 220 of first metal connector 1#, and the cathode layer 140 of tubular SOFC battery 1# is connected to the first cathode side metal connector 230 of first metal connector 2#; the conductive ceramic layer 130 of tubular SOFC battery 1# is connected to the first anode side metal connector 220 of first metal connector 2#, and the cathode layer 140 of tubular SOFC battery 1# is connected to the first cathode side metal connector 230 of first metal connector 2#, and so on. Meanwhile, the second metal connector 300 of the conductive ceramic layer 130 of the #1 tubular SOFC battery 100 is connected, and the third metal connector 400 of the cathode layer 140 of the #25 tubular SOFC battery 100 is connected.

[0039] It should be noted that, as Figure 3 and Figure 4 The 25 tubular SOFC batteries 100 shown can also be divided into five groups of five. Within the same group, the five tubular SOFC batteries 100 form a series circuit structure via corresponding first metal connectors 200, resulting in a total of five series circuit structures. Each series circuit structure then has its positive and negative terminals led out via corresponding second metal connectors 300 and third metal connectors 400, or each series circuit structure can have its positive and negative terminals led out via corresponding second metal connectors 300 and third metal connectors 400, and these connections can be combined to form a large parallel circuit structure.

[0040] The tubular SOFC module in this embodiment, compared to the traditional series connection of batteries with the anode and cathode connected end-to-end, shortens the current conduction path by 2 / 3 due to the first metal connector. This significantly reduces internal current loss caused by the internal resistance of the battery substrate, improving the power generation efficiency after assembly into a stack. The independent first metal connector design not only simplifies the stack assembly stage but also facilitates maintenance when stack units are damaged, improving the maintainability of the stack. The second and third metal connectors can adopt a double-connector design, allowing for more precise inspection and analysis of the stack during actual operation using a four-wire, two-electrode scheme.

[0041] In the optimized technical solution of this example, such as Figure 5 As shown, the first anode-side metal connector 220 and the second anode-side metal connector 320 are arc-shaped plates with radii approximately the same as the outer radius of the conductive ceramic layer 130 on the tubular SOFC battery 100. Preferably, the arc angle is 180° (i.e., the first anode-side metal connector 220 and the second anode-side metal connector 320 are semi-circular shells) to increase the contact area with the conductive ceramic layer 130. Simultaneously, the lengths of the first anode-side metal connector 220 and the second anode-side metal connector 320 are greater than the lengths of the corresponding conductive ceramic layers 130, but less than the length of the conductive ceramic layer 130 plus the transition electrolyte layer 120B, to provide sufficient conductive area and prevent short circuits. Furthermore, the first anode-side metal connector 220 and the second anode-side metal connector 320 employ a double-layer metal structure, and the coefficient of thermal expansion of the outer metal layer (the side furthest from the conductive ceramic layer 130) is greater than that of the inner metal layer, ensuring a stable connection at the anode position and perfect sealing at the conductive position at high temperatures.

[0042] In the optimized technical solution of this embodiment, such as Figure 5 As shown, the first cathode-side metal connector 230 and the third cathode-side metal connector 420 are arc-shaped plates, with their radii approximately the same as the outer radius of the cathode layer 140 on the tubular SOFC battery 100. Preferably, the arc angle is 45° (i.e., the first anode-side metal connector 220 and the second anode-side metal connector 320 are in a 1 / 4 circular shell shape) to ensure sufficient contact area between the first cathode-side metal connector 230 and the third cathode-side metal connector 420 and the cathode layer 140, ensuring circuit continuity. Simultaneously, the lengths of the first cathode-side metal connector 230 and the third cathode-side metal connector 420 are less than the lengths of the corresponding cathode layers 140.

[0043] Example 3

[0044] Figure 6 This is a three-dimensional structural diagram of the SOFC stack in Example 3. Figure 7 This is a three-dimensional structural diagram of the SOFC stack in Example 3, excluding the tubular SOFC assembly. Figure 6 and Figure 7 As shown, the SOFC stack includes the tubular SOFC assembly from Embodiment 2, and two stack mounting plates 500. The stack mounting plates 500 are made of ceramic material and have mounting through holes 510, the same number as the tubular SOFC cells 100. The diameter of the mounting through holes 510 is adapted to the outer diameter of both ends of the tubular SOFC cells 100. The two stack mounting plates 500 are arranged in parallel, and both ends of the tubular SOFC cells 100 are inserted into the corresponding mounting through holes 510 and filled and sealed with ceramic adhesive, thereby clamping the tubular SOFC assembly between the two stack mounting plates 500.

[0045] The SOFC stack in this embodiment can be flexibly designed according to actual needs, making it easy to design solid oxide fuel cell stacks of different specifications and realize high-power stack structure modules.

[0046] In the optimized technical solution of this embodiment, the mounting through hole 510 is a stepped hole with axial center coincidence. The diameter of the larger diameter section of the mounting through hole 510 is adapted to the outer diameter of both ends of the tubular SOFC battery 100; the other section of the mounting through hole 510 faces the outside of the stack fixing plate 500 and has a diameter smaller than the inner diameter of the tubular SOFC battery 100 (i.e., the inner diameter of the anode support tube 110). In this embodiment, because the mounting through hole adopts a two-section diameter design, the actual bonding surface between the end of the tubular SOFC battery and the stack fixing plate includes the outer circular surface and end face of the tubular SOFC battery, which is equivalent to forming a double sealing interface between the tubular SOFC battery and the stack fixing plate; at the same time, the diameter of the smaller diameter section of the mounting through hole is smaller than the inner diameter of the tubular SOFC battery, so the fuel gas intake airflow will not directly act on the connection between the tubular SOFC battery and the stack fixing plate, thereby further reducing the impact of airflow on the sealing material.

[0047] In the optimized technical solution of this embodiment, inlet and outlet gas diffusion chambers 600 are respectively provided on the outer side of the two fuel cell stack fixing plates 500. Figure 8 This is a three-dimensional structural diagram of the inlet and outlet gas diffusion chamber in Example 3. Figure 8As shown, the inlet / outlet diffuser compartment 600 is roughly a hollow trapezoidal platform made of ceramic material. Its larger open side is attached to the fuel cell stack mounting plate 500 and bonded together with ceramic adhesive and sintered, covering all the mounting holes 510. The inlet / outlet diffuser compartment 600 is also equipped with inlet / outlet pipes 610, whose axial length is perpendicular to the axial length of the tubular SOFC battery 100. In this embodiment, by providing the inlet / outlet diffuser compartment, gas can be supplied to the tubular SOFC battery simultaneously, preventing fuel gas from flowing directly to the tubular SOFC battery via the fuel cell stack mounting plate. Simultaneously, the directional design of the inlet / outlet pipes enables airflow deceleration and expansion pressure reduction, improving the uniformity of inlet / outlet pressure. More preferably, the inlet / outlet pipe 610 further includes an end-closed extension 620 extending along its axial length into the inlet / outlet diffuser chamber 600. The extension 620 has an air hole 630, the opening direction of which is perpendicular to the axial length of the tubular SOFC battery 100. In this embodiment, the cooperation between the extension and the air hole can further achieve the regulation of the inlet / outlet air and improve the uniformity of the outlet pressure.

[0048] In the optimized technical solution of this embodiment, a tensioning assembly 700 is also provided on both sides of the two fuel cell stack fixing plates 500. The tensioning assembly 700 may be composed of bolts 710, springs 720, washers 730, and nuts 740, etc. In this embodiment, the tensioning assembly applies stable pressure to the fuel cell stack fixing plates from both sides to ensure the tight connection of the battery sealing surface and enhance the stability of the overall fuel cell stack structure.

Claims

1. A tubular SOFC battery, comprising an anode support tube, characterized in that, At least two electrolyte layers are formed at intervals along the axial length of the outer peripheral wall of the anode support tube, and adjacent electrolyte layers are separated by conductive ceramic layers; along the axial length of the anode support tube, except for the two ends of the electrolyte layer in the length direction, a barrier layer is formed on the remaining part of each electrolyte layer; a cathode layer is formed on the barrier layer.

2. The tubular SOFC battery according to claim 1, characterized in that, The length of the electrolyte layer is greater than the length of the conductive ceramic layer; And / or, the length of the cathode layer is less than or equal to the length of the barrier layer.

3. The tubular SOFC battery according to claim 1 or 2, characterized in that, The anode support tube is formed with three electrolyte layers and two conductive ceramic layers at intervals.

4. A tubular SOFC assembly, characterized in that, The device includes at least two tubular SOFC batteries as described in any one of claims 1 to 3, and a first metal connector, a second metal connector, and a third metal connector; the first metal connector includes a first metal strip body, on which are respectively provided first anode-side metal connectors and first cathode-side metal connectors that correspond to the cathode layer and the conductive ceramic layer in a specific number; the first anode-side metal connector of the same first metal connector is connected to the corresponding conductive ceramic layer on one of the tubular SOFC batteries, and the first cathode-side metal connector of the same first metal connector is connected to the corresponding cathode layer on another tubular SOFC battery. The tubular SOFC cells are arranged in a series circuit structure. The second metal connector includes a second metal strip body, which has a second anode-side metal connector that matches the number and position of the conductive ceramic layers. The third metal connector includes a third metal strip body, which has a third cathode-side metal connector that matches the number and position of the cathode layers. The second anode-side metal connector is connected to the conductive ceramic layer of the tubular SOFC cell at the beginning of the series circuit structure, and the third cathode-side metal connector is connected to the cathode layer of the tubular SOFC cell at the end of the series circuit structure.

5. The tubular SOFC assembly according to claim 4, characterized in that, The first anode-side metal connector and the second anode-side metal connector are arc-shaped plates with the same radius as the outer radius of the corresponding conductive ceramic layer on the tubular SOFC battery, and their length is less than the length of the corresponding conductive ceramic layer. And / or, the first cathode-side metal connector and the third cathode-side metal connector are in the shape of an arc plate, the radius of which is the same as the outer radius of the corresponding cathode layer on the tubular SOFC battery, and the length of which is less than the length of the corresponding cathode layer.

6. The tubular SOFC assembly according to claim 4, characterized in that, The first anode-side metal connector and / or the second anode-side metal connector are semi-circular shell-shaped; And / or, the first anode-side metal connector and the second anode-side metal connector adopt a double-layer metal structure, and the coefficient of thermal expansion of the outer metal layer is greater than that of the inner metal layer; And / or, the first cathode-side metal connector and / or the third cathode-side metal connector are in the shape of a 1 / 4 circular shell.

7. A SOFC stack, characterized in that, The assembly includes a tubular SOFC module as described in any one of claims 4 to 6, and two stack mounting plates; the stack mounting plates have mounting through holes corresponding to the number of tubular SOFC cells, and the diameter of the mounting through holes is adapted to the outer diameter of both ends of the tubular SOFC cells; the two stack mounting plates are arranged in parallel, and both ends of the tubular SOFC cells are inserted into the corresponding mounting through holes and sealed with ceramic adhesive.

8. The SOFC stack according to claim 7, characterized in that, The mounting through hole is a stepped hole with the axial center coincident. The diameter of the larger section is adapted to the outer diameter of both ends of the tubular SOFC battery, and the diameter of the smaller section is smaller than the inner diameter of the tubular SOFC battery. And / or, tensioning components are also provided on the opposite sides of the two stack fixing plates.

9. The SOFC stack according to claim 7, characterized in that, The outer side of the fuel cell stack mounting plate is provided with an inlet / outlet diffuser compartment; the side of the inlet / outlet diffuser compartment facing the fuel cell stack mounting plate is open and covers all the mounting through holes; the inlet / outlet diffuser compartment is also provided with an inlet / outlet pipe, the axial length direction of the inlet / outlet pipe is perpendicular to the axial length direction of the tubular SOFC battery.

10. The SOFC stack according to claim 9, characterized in that, The inlet and outlet gas diffusion end chamber is a hollow trapezoidal platform, with its larger open side facing the fuel cell stack fixing plate; And / or, the inlet / outlet pipe further includes an end-closed extension extending along its axial length into the inlet / outlet diffuser chamber, the extension having an air hole, the opening direction of the air hole being perpendicular to the axial length direction of the tubular SOFC battery.

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