CN115084614B - A solid oxide fuel cell stack - Google Patents

Abstract

The invention provides a solid oxide fuel cell stack, comprising: the electric pile integral structure is formed by stacking a plurality of electric pile repeating units; conducting posts are respectively led out from the cathode side and the anode side of the whole galvanic pile structure; the electric pile repeating unit comprises a single cell, a first metal net, a connecting plate and a second metal net from bottom to top in sequence; the lower side of the single cell is an anode, and the upper side of the single cell is a cathode; an air flow channel is arranged at the lower side of the connecting plate, and the upper side of the connecting plate is a plane; and conductive leads are respectively led out of the first metal net, the air flow channel on the lower side of the connecting plate and the second metal net. Compared with the prior art, the solid oxide fuel cell stack provided by the invention adopts a specific structure to realize better integral interaction under a specific connection relation, improves the interface contact among modules in the stack, can realize in-situ monitoring of the electrical properties of each cell, a connecting plate and other components in the stack, and simultaneously detects the temperature field and gas phase distribution of the stack in real time.

Description

A solid oxide fuel cell stack

technical field

The invention relates to the technical field of electric stacks, and more specifically relates to a solid oxide fuel cell electric stack.

Background technique

Hydrogen energy and fuel cell technology, as an important innovative technology to promote low-carbon and environmentally friendly economic and social development, is a strategic choice for my country to respond to global climate change, ensure national energy supply security, and achieve sustainable development. In recent years, hydrogen energy and fuel cell technology have become an important development direction of my country's energy strategy. The types of fuel cells include proton exchange membrane fuel cells, solid oxide fuel cells and alkaline fuel cells. Solid oxide fuel cells (Solid Oxide FuelCells, SOFCs), as an all-solid fuel cell, is an efficient and clean energy technology that can directly convert the chemical energy of methane, hydrogen and other fuels into electricity or heat without generating any hazardous substance. SOFC has the advantages of adjustable power, continuous stability, low exhaust gas emissions, high co-generation efficiency, and low battery cost. It is suitable for small household power supplies, distributed power stations, and military portable power systems. Under the background of energy shortage and strict requirements for environmental protection in the 21st century, SOFC has important research value for new energy technologies without pollution to the environment, and has attracted extensive attention in various fields.

The structure of SOFC stack is mainly divided into flat plate type, round tube type and flat tube type. Flat-plate SOFC has high space utilization and is relatively simple to prepare, but it takes a long time to start and stop; circular-tube SOFC has strong thermal shock resistance, short start-up and shutdown, but low space utilization and volumetric power density; flat-tube SOFC Combining the structural advantages of flat plates and round tubes is one of the important development directions of SOFC technology. Its thick supporting anode greatly improves the mechanical strength of the battery, has strong thermal shock resistance, and also improves the long-term operation stability of the battery. However, the power of a single cell is small, and the open circuit voltage (OCV) is only 1.23V at the highest, so the application field is limited, so it is necessary to assemble multiple single cells and connection plates into a stack between kilowatts and megawatts, flat tube high power Stacks are in urgent demand. The operating environment of the SOFC stack is harsh, and the operating temperature is between 650°C and 850°C. The stack is sealed and isolated from the outside air as a whole. It is necessary to analyze the internal cell voltage of the stack, the resistance of the connection plate and the interface contact resistance between the single cell and the connection plate without destroying the internal structure of the stack and without affecting the normal operation of the stack. However, there are currently problems such as the performance of the internal components of the stack cannot be detected in real time or the detection signal is unstable. If the performance of the stack drops suddenly, the test can only be stopped by cooling down, and the stack is disassembled for analysis. The disassembled stack will no longer be usable. It will cause a waste of resources and greatly increase the cost of the stack.

The current stack detection methods mostly focus on the proton exchange membrane fuel cell stack, because the structure of the proton exchange membrane fuel cell stack and the solid oxide fuel cell stack is different, the detection method of the proton exchange membrane fuel cell stack is not applicable. There are many test systems for solid oxide fuel cells, but the specific operation method of the detection in the stack is not specified.

Contents of the invention

In view of this, the purpose of the present invention is to provide a solid oxide fuel cell stack. The solid oxide fuel cell stack provided by the present invention improves the interface contact between the modules in the stack, and can realize in-situ monitoring The electrical performance of each battery, connection plate and other components in the stack, and at the same time detect the temperature field and gas phase distribution of the stack in real time.

The invention provides a solid oxide fuel cell stack, comprising:

The overall structure of the stack formed by stacking several repeating units of the stack; the cathode side and the anode side of the overall structure of the stack respectively lead to conductive columns;

The stack repeating unit is a single cell, a first metal mesh, a connecting plate and a second metal mesh from bottom to top; the lower side of the single cell is an anode, and the upper side is a cathode; the lower side of the connecting plate is provided with The upper side of the air channel is plane; the first metal mesh, the air channel on the lower side of the connecting plate and the second metal mesh respectively lead out conductive leads.

Preferably, the number of repeating units of the stack is 2-40.

Preferably, the single cell is a solid oxide fuel cell with a single-cathode flat tube structure.

Preferably, the structure of the single-cathode flat-tube solid oxide fuel cell is:

8YSZ|NiO-8YSZ|NiO-YSZ|NiO-8YSZ|8YSZ|GDC|LSC;

Among them, 8YSZ is the electrolyte, NiO-8YSZ is the active anode, NiO-YSZ is the anode support, GDC is the barrier layer, and LSC is the cathode layer.

Preferably, the thickness of the 8YSZ is 7~9 μm; the thickness of the NiO-8YSZ is 4~6 μm; the size of the NiO-YSZ is (150~160) mm×(60~62) mm×(4~ 6) mm, with fuel channel holes with a diameter of 0.5mm~1.5mm evenly distributed in the middle; the thickness of the GDC is 1~3μm; the size of the LSC is (120~130)mm×(60~62)mm, The thickness is 10~20μm.

Preferably, one side of the single-cathode flat-tube solid oxide fuel cell has a (40-60) mm×(120-140) mm rectangle in the middle as an electron collecting window, and the other side is a cathode layer.

Preferably, the first metal mesh is silver mesh or platinum mesh; the thickness of the first metal mesh is 0.05mm~0.15m, and the mesh size is (0.2~0.4)mm×(0.5~0.7)mm.

Preferably, the connecting plate is made of Crofer22 metal, SUS430 metal or SUS441 metal;

The air channel of the connecting plate is a groove of 1 mm to 2 mm.

Preferably, the second metal mesh is a nickel mesh; the thickness of the second metal mesh is 0.05mm~0.1m, and the mesh size is (0.1~0.3)mm×(0.3~0.5)mm.

Preferably, the material of the conductive lead is Crofer22 metal, SUS430 metal or SUS441 metal;

The diameter of the conductive lead is 0.4mm-0.6mm.

The present invention provides a solid oxide fuel cell stack, comprising: an overall stack structure formed by stacking several stack repeating units; conductive columns are respectively drawn from the cathode side and the anode side of the overall stack structure; The stack repeating unit is a single cell, a first metal mesh, a connecting plate and a second metal mesh from bottom to top; the lower side of the single cell is an anode, and the upper side is a cathode; the lower side of the connecting plate is provided with an air The upper side of the flow channel is a plane; the first metal mesh, the air flow channel on the lower side of the connecting plate and the second metal mesh respectively lead out conductive leads. Compared with the prior art, the solid oxide fuel cell stack provided by the present invention adopts a specific structure to achieve overall better interaction under a specific connection relationship, improves the interface contact between modules in the stack, and can realize in-situ Monitor the electrical performance of each battery, connection plate and other components in the stack, and simultaneously detect the temperature field and gas phase distribution of the stack in real time.

Description of drawings

Fig. 1 is a schematic diagram of an assembled three-dimensional structure of a solid oxide fuel cell stack provided by an embodiment of the present invention;

Fig. 2 is a schematic diagram of the complex unit structure of the solid oxide fuel cell stack provided by the embodiment of the present invention;

Fig. 3 is the volt-ampere characteristic curve of the solid oxide fuel cell stack provided by the embodiment of the present invention;

Fig. 4 is the discharge curve of the single cell and the connecting plate in the solid oxide fuel cell stack provided by the embodiment of the present invention;

Fig. 5 is the interface resistance between the single cell and the connecting plate during the constant current discharge process of the solid oxide fuel cell stack provided by the embodiment of the present invention.

Detailed ways

The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

The invention provides a solid oxide fuel cell stack, comprising:

The overall structure of the stack formed by stacking several repeating units of the stack; the cathode side and the anode side of the overall structure of the stack respectively lead to conductive columns;

The stack repeating unit is a single cell, a first metal mesh, a connecting plate and a second metal mesh from bottom to top; the lower side of the single cell is an anode, and the upper side is a cathode; the lower side of the connecting plate is provided with The upper side of the air channel is plane; the first metal mesh, the air channel on the lower side of the connecting plate and the second metal mesh respectively lead out conductive leads.

The present invention aims at the prior art "(1) It is impossible to in-situ monitor the performance of components in the high-power electric stack; (2) When the electric stack runs for a long time, the power of the electric stack decreases due to the increase of the interface resistance; (3) In the electric stack For the technical problem of in-situ monitoring and recording of temperature and other signals at various positions”, a solid oxide fuel cell stack is provided. The temperature signal can also be calculated to obtain the interface resistance data; on the other hand, it can improve the interface contact between the battery anode and the connecting plate, the battery cathode and the connecting plate in the stack; and can detect the temperature field and gas phase distribution in the stack in real time , can be fixed at any position of the metal mesh through a thermocouple or a gas collection tube, so that the temperature and gas phase distribution of each position of the battery can be detected.

In the present invention, the solid oxide fuel cell stack includes: an overall stack structure formed by stacking several stack repeating units; the cathode side and the anode side of the overall stack structure lead out conductive columns respectively.

In the present invention, the number of the stack repeating units is preferably 2-40, more preferably 3-10.

In the present invention, the stack repeating unit is a single cell, a first metal mesh, a connecting plate, and a second metal mesh from bottom to top; the lower side of the single cell is an anode, and the upper side is a cathode; the connection The lower side of the board is provided with an air flow channel, and the upper side is a plane; the first metal mesh, the air flow channel and the second metal mesh on the lower side of the connecting plate respectively lead out conductive leads.

In the present invention, the single cell is preferably a single-cathode flat-tube solid oxide fuel cell; the structure of the single-cathode flat-tube solid oxide fuel cell is preferably:

8YSZ|NiO-8YSZ|NiO-YSZ|NiO-8YSZ|8YSZ|GDC|LSC;

Among them, 8YSZ is the electrolyte, NiO-8YSZ is the active anode, NiO-YSZ is the anode support, GDC is the barrier layer, and LSC is the cathode layer.

In the present invention, the thickness of the 8YSZ is preferably 7-9 μm, more preferably 8 μm; the thickness of the NiO-8YSZ is preferably 4-6 μm, more preferably 5 μm; the size of the NiO-YSZ is preferably (150 ~160)mm×(60~62)mm×(4~6)mm, more preferably 155mm×61mm×5mm, with fuel channel holes with a diameter of 0.5mm~1.5mm evenly distributed in the middle; the thickness of the GDC is preferably 1-3 μm, more preferably 2 μm; the size of the LSC is preferably (120-130) mm×(60-62) mm, more preferably 125 mm×61 mm, and the thickness is preferably 10-20 μm, more preferably 15 μm.

In the present invention, a rectangle of (40-60) mm×(120-140) mm (more preferably 50 mm×130 mm) is preferably opened in the middle of one side of the solid oxide fuel cell with a single-cathode flat tube structure, as an electron The current collecting window and the other side is the cathode layer.

In the present invention, the first metal mesh is preferably silver mesh or platinum mesh; the thickness of the first metal mesh is preferably 0.05mm~0.15m, more preferably 0.1mm, and the mesh size is preferably (0.2~0.4 ) mm×(0.5~0.7) mm, more preferably 0.3 mm×0.6 mm.

In the present invention, the material of the connecting plate is preferably Crofer22 metal, SUS430 metal or SUS441 metal, more preferably SUS441 metal; the above-mentioned material is a metal with good electrical conductivity and strong oxidation resistance, and the present invention has no special reference to its source. limit.

In the present invention, the air passage of the connecting plate is preferably a groove of 1 mm to 2 mm, more preferably a groove of 1.5 mm.

In the present invention, the second metal mesh is preferably a nickel mesh; the thickness of the second metal mesh is preferably 0.05mm~0.1m, and the mesh size is preferably (0.1~0.3)mm×(0.3~0.5)mm , more preferably 0.2mm×0.4mm.

In the present invention, the material of the conductive lead is preferably Crofer22 metal, SUS430 metal or SUS441 metal, more preferably SUS441 metal; the diameter of the conductive lead is preferably 0.4mm-0.6mm, more preferably 0.5mm.

In the present invention, see Figures 1 to 2, wherein Figure 1 is a schematic diagram of an assembled three-dimensional structure of a solid oxide fuel cell stack provided by an embodiment of the present invention, wherein 1 is a conductive column, and 2 is a repeating unit ①, 3 is a repeating unit ②, 4 is a lead ①, 5 is a lead ②, 6 is a lead ③, 7 is a single cell, 8 is a metal mesh, and 9 is a connecting plate; Fig. 2 is a solid oxide fuel cell provided by an embodiment of the present invention Schematic diagram of the complex unit structure of the electric stack, wherein, 4 is the lead wire ①, 5 is the lead wire ②, 6 is the lead wire ③, 7 is the single cell, 8 is the metal mesh, and 9 is the connecting plate; the preparation of the above-mentioned solid oxide fuel cell stack The method preferably includes:

(1) Preparation of components:

A single-cathode solid oxide fuel cell with a flat tube structure is selected for the single cell. First, the anode support NiO-YSZ is prepared by extrusion molding, and a layer of active anode NiO-8YSZ is prepared on the outside of the anode support by silk screen method. On the outside of the active anode Prepare a layer of electrolyte 8YSZ. A rectangle of (40~60) mm×(120~140) mm is opened in the middle of one side of the battery as the electron collecting window. A layer of barrier layer GDC is continued to be screen-printed on the outer layer of the electrolyte. On the other side, silk screen the cathode layer.

A thin metal mesh with good conductivity (silver mesh or platinum mesh) is added between the cathode of the single cell and the connection plate. The position is shown as the metal mesh 8 (below the connection plate 9) in Figure 2. The area of the metal mesh is the same as the area of the cathode Similarly, because of its high electrical conductivity and low hardness, it can increase the contact area between the flow channel side of the connecting plate and the battery cathode, thereby reducing the interface contact resistance and increasing the discharge power of the stack.

A nickel mesh metal mesh is added between the anode of the single cell and the connection plate, the position is shown as the metal mesh 8 (above the connection plate 9) in Figure 2, and the area of the metal mesh is consistent with the current collecting window.

The material of the conductive lead is preferably consistent with the material of the connecting plate, which improves the interface contact under high pressure and reduces the test error; the contact part of the conductive lead and the stack is rolled into a 0.1~0.3μm thick sheet by a roller press.

Material treatment of conductive leads: screen-print the cathode material of the battery on the surface of the contact part of the conductive lead and the cathode of the stack battery, about 10 μm, which can be LSC, LSCF, LSM, etc., preferably LSC; through the above material treatment, it is consistent with the material of the battery cathode, The contact resistance between different components can be reduced, and the accuracy of signal collection can be improved.

(2) Assembly of the stack:

Assembled by repeating unit ①: single cell, first metal mesh, connecting plate, second metal mesh; repeating unit ②: single cell, first metal mesh, connecting plate, second metal mesh are stacked continuously, repeating unit 3 One, the conductive columns are respectively drawn from the cathode and anode of the stack, which can be used to collect current and voltage signals at the same time.

In the present invention, the electric stack is an electric stack assembled with hollow flat tube batteries; the cathode and anode sides of the electric stack lead out conductive columns respectively, so as to avoid power loss caused by long electron transmission paths.

Place the conductive lead wire at the groove in the flow channel, as shown by the lead wire ② (reference number 5) in Figure 2, which can avoid affecting the contact between the single cell and the connecting plate, improve the accuracy, and fix it on the metal by welding The connection board is convenient and stable without breaking, so as not to cause test interruption and data loss; the conductive leads can also be placed in different positions to analyze different performance parameters, such as the battery anode and the connection board cathode, as shown in Figure 2. Lead ① (reference number 4), the interface contact resistance between the battery cathode and the connection plate, and between the battery anode and the connection plate can be analyzed respectively; because the interface contact resistance of the stack cannot be directly tested during actual operation, it can only be tested by Simulated model test, and this method of the present invention can be directly tested and obtained during the actual operation of the stack; because the parts of the lead test include the battery and the connection board, it will not fail to test because the resistance of the connection board is low, and can reduce the Test equipment accuracy and reduce costs.

Fix a thermocouple with a diameter of 0.5mm or a conductive lead wire on the metal mesh by interspersing, as shown in the lead wire ① (reference number 4) in Figure 2, which can firmly fix the lead wire to avoid the occurrence of damage during the operation of the stack. The lead wire is shifted or partially broken, causing the test to be interrupted and the data missing; the thermocouple can be fixed at the gas inlet, the center of the stack, the outlet and other positions that need to be monitored, such as the lead wire ③ in Figure 2 (reference number 6); the gas The collection tube can also be fixed in the air flow channel by interspersing, and the gas phase distribution in different regions of the stack can be tested by fixing it at different positions.

In the present invention, the performance of components such as batteries and connecting plates in the electric stack can be monitored in real time; adding conductive leads between the battery and the connecting plate does not damage the internal structure of the electric stack, does not affect the normal operation of the electric stack, and the test method is simple and easy operation, and the cost of the lead wire is low and can be used repeatedly; the conductive lead wire can be fixed to different positions on the connecting plate by welding; the conductive lead wire can be surface treated to avoid the impact of the addition of the conductive lead wire on the normal test of the stack.

In the present invention, a metal mesh is added between the battery anode and the connection plate, between the battery cathode and the connection plate, and the conductive lead wire, thermocouple or gas collection tube can be fixed on the metal mesh by interspersing; it can be fixed on any position on the metal mesh, Real-time monitoring of the performance of each area; this method can not only detect the performance of the single cell and connection board in the stack, but also obtain the interface contact resistance between the single cell and the connection board, and improve the contact resistance between the battery and the connection board. Interface contact, improve the discharge power of the stack.

(3) Electrical signal processing method:

Data such as current, voltage, and power can be collected through the conductive columns of the anode and cathode of the stack, so as to avoid the voltage loss of the stack due to the long electron transmission path during the test. Through the conductive leads, the voltage and resistance signal changes between the single cells, connecting plates and components of the stack can be detected during the open circuit and discharge process. The voltage of the connection board can be obtained by subtracting the voltage of the battery from the voltage of the test battery and the connection board, and then the resistance of the connection board can be calculated from the current data, so as to avoid the situation that the resistance of the connection board is too small to be detected.

If a single cell fails in the actual operation of the stack, the single cell can be short-circuited by contacting the lead wires on both sides of the cathode and anode of the single cell, and the power output of the single cell can be directly discarded, so as to avoid affecting the stack. The total power may cause the stack to fail, which avoids scrapping the stack.

The beneficial effects of the solid oxide fuel cell stack provided by the present invention are specifically described as follows:

(1) In-situ monitoring of the electrical properties of each battery, connection plate and other components in the stack;

The discharge power of the SOFC stack is large, the assembly cost is high, and it operates in a high temperature and airtight environment after assembly. It can only detect the total output performance of the stack, and it is difficult to detect the operation of the internal cells, connecting boards and modules in the stack. However, the performance of a unit module will affect the total output performance of the stack, including current and voltage; the operation status of each component inside the stack cannot be obtained through the total current and voltage data of the stack, and the components that make up the stack cannot be analyzed. Evaluate the performance of components; for example, the failure of a single battery will cause a sudden increase in interface resistance and a decrease in current. If the cause cannot be analyzed to improve this situation, the operation of the stack can only be stopped, and the stack can no longer be used, resulting in waste of resources; therefore, it is necessary to On the premise of not destroying the internal structure, real-time monitoring of the components inside the stack is carried out; if abnormal conditions are detected, the specific module where the problem occurs can be analyzed, and the operation can be carried out in time; the performance of each component can be simulated through the operation of the stack Environmental method detection, but the actual operating environment of the stack is complex, and real-time detection is required for analysis.

The present invention can analyze the voltage of a single battery in the stack and the voltage of the connecting plate without affecting the normal operation of the stack, and then calculate the power of the battery and the resistance of the connecting plate according to the current signal; place the conductive leads on different Different performance parameters can be analyzed at different positions, for example, when placed on the battery anode and the connection plate cathode, the interface contact resistance between the battery cathode and the connection plate, and between the battery anode and the connection plate can be analyzed; because the interface contact of the stack during actual operation It cannot be directly tested, but can only be tested through a simulation model, and the method of the present invention can be directly tested during the actual operation of the electric stack; Contact the conductive leads on both sides of the cathode and anode of the single cell to short-circuit the single cell to prevent the failure of the single cell from affecting the total output power of the stack, and avoid stopping the operation of the stack.

(2) Improve the interface contact between modules in the stack;

There are many reasons that affect the total output performance of the stack, including the performance of each component and the contact between components; the operating life of the stack is usually required to be more than 100,000h. During the long-term discharge operation of the stack, the components between components The assembly of the battery is also an important factor affecting the output performance of the battery stack. If the contact between the battery and the connecting plate is poor, the interface contact resistance will be increased and the output current of the battery stack will be reduced.

By adding a thin silver mesh and other conductive metal mesh between the single cell and the connection plate, because of its high conductivity and low hardness, the contact area between the flow channel side of the connection plate and the battery cathode can be increased. , thereby reducing the interface contact resistance and increasing the discharge power of the stack.

(3) Real-time detection of the temperature field and gas phase distribution of the stack;

The discharge power of the SOFC stack is large, the assembly cost is high, and it operates in a high temperature and airtight environment after assembly. It is difficult to detect the operation of the internal single cells and connection board modules in the stack. At the same time, the performance of a unit module will affect the performance of the stack. Total output performance, including current and voltage; for example, the failure of a single cell causes a sudden increase in interface resistance and a decrease in current; therefore, it is necessary to monitor the components inside the stack in real time without destroying the internal structure; if abnormalities are detected According to the situation, the specific module where the problem occurs can be analyzed, and the operation can be handled in a timely manner.

By adding a metal mesh between the battery and the connection plate, it can not only serve as an electron collection layer to improve the interface contact between the battery cathode and the connection plate, the battery anode and the connection plate, but also firmly fix the thermocouple on the battery and the connection plate Any position in the stack can realize temperature detection at any position in the stack and analyze the distribution of the temperature field in the stack; you can also add many other conductive leads in the metal mesh, including gas collection tubes, etc., to collect gas components at different positions and analyze them. The operation of the cells in the stack. Conductive leads are placed in different positions to analyze the performance of different components in different regions.

The present invention provides a solid oxide fuel cell stack, comprising: an overall stack structure formed by stacking several stack repeating units; conductive columns are respectively drawn from the cathode side and the anode side of the overall stack structure; The stack repeating unit is a single cell, a first metal mesh, a connecting plate and a second metal mesh from bottom to top; the lower side of the single cell is an anode, and the upper side is a cathode; the lower side of the connecting plate is provided with an air The upper side of the flow channel is a plane; the first metal mesh, the air flow channel on the lower side of the connecting plate and the second metal mesh respectively lead out conductive leads. Compared with the prior art, the solid oxide fuel cell stack provided by the present invention adopts a specific structure to achieve overall better interaction under a specific connection relationship, improves the interface contact between modules in the stack, and can realize in-situ Monitor the electrical performance of each battery, connection plate and other components in the stack, and simultaneously detect the temperature field and gas phase distribution of the stack in real time.

In order to further illustrate the present invention, the following examples are described in detail below.

Example

Referring to Figures 1 to 2, wherein, Figure 1 is a schematic diagram of an assembled three-dimensional structure of a solid oxide fuel cell stack provided by an embodiment of the present invention; Figure 2 is a complex structure of a solid oxide fuel cell stack provided by an embodiment of the present invention Schematic diagram of the unit structure.

By adding conductive leads to the electric stack assembled by three single cells, it is possible to collect electrical signals from components such as batteries and connection plates during the discharge process of the electric stack.

In the embodiment of the present invention, three flat-tube SOFC single cells are selected to be assembled into a stack, and the single-cathode single-cathode flat-tube structure solid oxide fuel cell is selected for the single cell, and the structure is:

8YSZ|NiO-8YSZ|NiO-YSZ|NiO-8YSZ|8YSZ|GDC|LSC;

Among them, the anode support body NiO-YSZ has a size of 155mm×61mm×5mm, and fuel flow channel holes with a diameter of 1mm are evenly distributed in the middle; there is a layer of active anode NiO-8YSZ on the outside of the anode support body, with a thickness of about 5 μm; there is a layer of Electrolyte, 8YSZ, with a thickness of about 8 μm. There is a 50mm×130mm rectangle in the middle of one side of the battery as an electron collection window; there is a barrier layer GDC on the outer layer of the electrolyte, with a thickness of about 2 μm; the other side of the battery is the cathode layer, It is LSC material, 125mm×61mm, and the thickness is about 15μm.

The material of the connecting plate is SUS441 metal. There is an air flow channel on the side in contact with the battery cathode. The air flow channel is a 1.5mm groove, and the other side in contact with the battery anode is a plane.

Add a thin metal mesh (platinum mesh) with good conductivity between the cathode of the single cell and the connecting plate, the position is shown as the metal mesh 8 (below the connecting plate 9) in Figure 2, the thickness is 0.1mm, and the mesh is 0.3mm ×0.6mm, the area of the metal mesh is the same as the cathode area, because of its high conductivity and low hardness, it can increase the contact area between the flow channel side of the connecting plate and the battery cathode, thereby reducing the interface contact resistance and increasing the stack discharge power.

A nickel mesh metal mesh is added between the anode of the single cell and the connection plate, the position is shown as the metal mesh 8 (above the connection plate 9) in Figure 2, the thickness is 0.05mm~0.1mm, the mesh is 0.2mm×0.4mm, and the metal The mesh area is consistent with the flow collecting window.

The conductive lead material is SUS441 with a diameter of 0.5mm. The contact part of the conductive lead and the stack is rolled into a thin sheet with a thickness of 0.1μm~0.3μm by a roller press; the cathode material of the battery is screen-printed on the surface of the contact part of the conductive lead and the stack battery , about 10 μm.

When assembled according to the structure in Figure 1, the six conductive leads are respectively placed on the cathode and anode of battery #1#2#3 (first conductive lead | battery #1 anode | second conductive lead | battery #1 cathode | third conductive Lead | Battery #2 Anode | Fourth Conductive Lead | Battery #2 Cathode | Fifth Conductive Lead | Battery #3 Anode | Sixth Conductive Lead | The metal mesh is fixed.

After the three batteries are assembled according to the structure shown in Figure 1, they are placed in a heating furnace to keep the stack at 750°C. The anode side of the battery is fed with 0.6SLM hydrogen for reduction, and the cathode side is fed with 1.8SLM air. After 4 hours of reduction, the instantaneous discharge test was started, hydrogen gas was passed into 2SLM, and air was passed into 6SLM, and the volt-ampere characteristic curve of the stack as shown in Figure 3 was obtained.

Figure 3 is the current-voltage-power curve of the three-unit stack during the instantaneous discharge process. The current and voltage signals are collected through the conductive pillars on the cathode and anode sides of the stack. The voltage is 3V and the power is 64.8W.

General stack tests can only obtain the data in Figure 3, but the solid oxide fuel cell stack provided by the present invention can simultaneously obtain the data of the single cell and the connection plate shown in Figure 4 during the discharge process.

The discharge test method is the same as that of the above-mentioned electric stack, and the discharge curve of the single cell and the connecting plate in the three-unit electric stack in Figure 4 is obtained. The I-V data of battery #1 is obtained through the first conductive lead and the second conductive lead on both sides of the battery, and the power P It is calculated by I×V; the same is true for battery #2#3, and the data of battery #1+connection plate is obtained through the first conductive lead and the third conductive lead.

Through these data, the instantaneous single-cell performance in the stack and the resistance of the connection plate can be analyzed in situ; at the same time, it can be seen that the total power of the three batteries + the connection plate is 69.5W, which is slightly greater than the power of the stack, which is 64.8W. Therefore, it is speculated that the contact between batteries is optimized and the interface resistance loss is reduced by using the electric stack of the present invention for testing.

The three-unit stack was subjected to constant current discharge for 107 hours at a current of 14A. Figure 5 shows the interface resistance between the single cell and the connecting plate during the constant current discharging process, including the interface resistance between the battery anode and the connecting plate, and between the battery cathode and the connecting plate. interface resistance. It can be seen that the change of the interface resistance of the stack during the long-term discharge process can also be obtained through the electric stack of the present invention, and the interface resistance values in the figure are all less than 0.3mΩ.

In summary, the solid oxide fuel cell stack provided by the present invention has the following beneficial effects:

(1) The solid oxide fuel cell stack provided by the present invention can realize in-situ monitoring of the electrical properties of each battery, connecting plate and other components in the stack, and the interface resistance between the battery and the connecting plate without damaging the internal structure of the stack , does not affect the discharge performance output of the stack;

(2) It can not only detect the electrical performance of each battery, connecting plate and other components in the stack, but also improve the interface contact between the battery anode and the connecting plate, the battery cathode and the connecting plate in the stack;

(3) Real-time detection of the temperature field and gas phase distribution in the stack; thermocouples or gas collection tubes can be fixed at any position of the metal mesh, so that the temperature and gas phase distribution of each position of the battery can be detected.

The above description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention will not be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (1)

1. A solid oxide fuel cell stack is characterized in that the stack is of an integral structure formed by stacking a plurality of stack repeating units; conducting posts are respectively led out from the cathode side and the anode side of the whole galvanic pile structure;

the electric pile repeating unit comprises a single cell, a first metal net, a connecting plate and a second metal net from bottom to top in sequence; the lower side of the single cell is an anode, and the upper side of the single cell is a cathode; an air flow channel is arranged at the lower side of the connecting plate, and the upper side of the connecting plate is a plane; conductive leads are respectively led out of the first metal net, the air flow channel on the lower side of the connecting plate and the second metal net;

the single cell is a Shan Yinji flat tube type structure solid oxide fuel cell; the Shan Yinji flat tube type solid oxide fuel cell has the structure that:

8YSZ|NiO-8YSZ|NiO-YSZ|NiO-8YSZ|8YSZ|GDC|LSC；

wherein 8YSZ is an electrolyte, niO-8YSZ is an active anode, niO-YSZ is an anode support body, GDC is a barrier layer, and LSC is a cathode layer;

the thickness of the 8YSZ is 7-9 mu m; the thickness of the NiO-8YSZ is 4-6 mu m; the NiO-YSZ has the size of (150-160) mmX (60-62) mmX (4-6) mm, and fuel flow channel holes with the diameter of 0.5-1.5 mm are uniformly distributed in the middle; the thickness of the GDC is 1-3 mu m; the LSC has the size of (120-130) mmx (60-62) mm and the thickness of 10-20 mu m;

the number of the electric pile repeating units is 2-40;

the Shan Yinji flat tube type structure solid oxide fuel cell is characterized in that a rectangle with the thickness of (40-60) mmX (120-140) mm is arranged in the middle of one surface of the solid oxide fuel cell and is used as an electronic current collecting window, and the other surface of the solid oxide fuel cell is a cathode layer;

the first metal net is a silver net or a platinum net; the thickness of the first metal net is 0.05 mm-0.15 m, and the mesh size is (0.2-0.4) mmX (0.5-0.7) mm;

the connecting plate is made of Crofer22 metal, SUS430 metal or SUS441 metal;

the air flow channel of the connecting plate is a groove with the thickness of 1 mm-2 mm;

the second metal net is a nickel net; the thickness of the second metal net is 0.05 mm-0.1 m, and the mesh size is (0.1-0.3) mmX (0.3-0.5) mm;

the conductive lead is made of Crofer22 metal, SUS430 metal or SUS441 metal;

the diameter of the conductive lead is 0.4 mm-0.6 mm.

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