Single-cell module, large-scale fuel cell stack based on single-cell module, and integration method for large-scale fuel cell stack

Abstract

A single-cell module, a large-scale fuel cell stack based on the single-cell module, and an integration method for the large-scale fuel cell stack. The module is formed by stacking several single cells, and the single cells are connected and fixed by means of hollow inserts. The stack comprises several single-cell modules, and during integration, a cathode end plate, a cathode mounting plate, an anode mounting plate and an anode end plate are provided at the top and bottom of each single-cell module, so as to form a short stack; and pre-compression is performed on the short stack, pre-activation and performance testing are then performed on the short stack, and several single-cell modules that meet standards are stacked in sequence and then compressed and encapsulated. By using the single-cell module as a unit module, the number of stacked components can be greatly reduced, thereby improving the reliability of a stacking process; in addition, a quality problem of a single cell can be discovered in a module stage in a timely manner, and the single cell can be replaced, thereby ensuring the consistency of the performance of single cells in respective modules, and the single-cell module has structural independence, thereby facilitating process control over production, storage and disassembly by means of a traceability code of each module.

Description

A single cell module, a large fuel cell stack based on the single cell module, and an integration method thereof Technical Field

[0001] The present invention relates to a high-power fuel cell stack integration technology exceeding 500 kW, and in particular to a single cell module, a large fuel cell stack based on the single cell module, and an integration method thereof. Background Art

[0002] A single cell is the basic unit of a fuel cell stack, consisting of a bipolar plate assembly, a membrane electrode assembly, and the required seals, also known as a three-in-one assembly. The single cell design is intended to reduce the number of components during the stacking process, facilitating quality control and ensuring consistent performance between cells. A single cell serves as a semi-finished product and a key component in the production process. The single cell process is currently a popular integration process, but is suitable for low-power fuel cell stacks below 100 kilowatts.

[0003] However, with the market's demand for increased power of battery stacks, especially for ultra-high-power battery stacks, such as more than a thousand 500-kilowatt battery stacks, the process of using single-cell components as the basic stacking unit becomes too cumbersome, and fatal quality defects are easily introduced due to personnel fatigue. In addition, quality defects from raw materials will only appear during the activation process after the battery stack is completed, and cannot be judged before or during the stacking process. Once it is found during the activation or testing process that the performance differences between single cells are large and begin to affect the performance of the battery stack, the problematic single cell must be replaced. The replacement process requires the single cells of the battery stack to be carefully moved and placed in the line-side warehouse. Because the number of single cells is large, the entire disassembly and replacement process is prone to introduce new failure factors, so one disassembly is not sure to solve all quality problems, and repeated disassembly and assembly (up to 5 times) will cause the performance of the battery stack to degrade.

[0004] Summary of the Invention

[0005] Purpose of the invention: The technical problem to be solved by the present invention is to provide a single-cell module. The use of the single-cell module reduces the number of basic units in the stacking process, improves the reliability of the stacking process, avoids the side effects of disassembling the large fuel cell stack after stacking the single cells, and the single-cell module has structural independence. The traceability code of each single-cell module facilitates the process control of production, storage and disassembly.

[0006] Technical solution: The single battery module of the present invention is composed of several groups of single batteries stacked together, and the several groups of single batteries are connected and fixed by hollow inserts;

[0007] The hollow insert includes an outer sleeve and an inner sleeve that cooperates with the outer sleeve. The end faces of the outer sleeve and the inner sleeve each have a sleeve cover to respectively fix the uppermost and lowermost plates of the single battery module. A tensioning member connecting the outer sleeve and the inner sleeve is provided in the inner sleeve, and the sleeve covers of the outer sleeve and the inner sleeve are respectively provided with anchors that cooperate with the tensioning member.

[0008] Furthermore, a plug hole is provided on the single cell module away from the active area and the sealing area, the hollow insert is arranged in the plug hole, and the thickness of the tube cover of the hollow insert is less than the thickness of the single cell plate.

[0009] Furthermore, the upper and lower cylinder covers of the hollow insert of the single battery module cooperate with each other in a male-female docking manner.

[0010] Furthermore, the outer sleeve of the hollow insert of the single cell module is tightly against the insertion hole so that several groups of single cells are aligned with each other, and the lengths of the outer sleeve and the inner sleeve are shorter than the height of the single cell module after pre-compression.

[0011] Furthermore, the anchoring member of the single battery module is a pin or an anchor, which is provided on the cylinder cover, and the tensioning member is a spring or an elastic band.

[0012] Furthermore, the outer sleeve and the inner sleeve cover of the single battery module are provided with slots for accommodating anchoring pieces.

[0013] Furthermore, the upper and lower electrode plate end faces of the single battery module are matched with each other in a concave-convex docking manner to achieve docking between several single battery modules.

[0014] The large fuel cell stack of the present invention comprises several groups of the above-mentioned single cell modules, as well as cathode tail plates, cathode mounting plates, anode mounting plates and anode tail plates arranged above and below the single cell modules.

[0015] The method of integrating the above-mentioned large fuel cell stack of the present invention comprises the following steps:

[0016] (1) Stacking several groups of single cells in sequence and connecting and fixing them with hollow inserts to form a single cell module;

[0017] (2) A cathode tail plate, a cathode mounting plate, an anode mounting plate, and an anode tail plate are arranged above and below the single cell module to form a short stack;

[0018] (3) Pre-press the short stack, and perform pre-activation and performance testing on the short stack; reserve the single cell modules that meet the single cell consistency performance standards; detect and remove the problem single cells, and re-stack them for pre-activation and performance testing until the performance of all single cell modules meets the preset requirements;

[0019] (4) After stacking several groups of single battery modules that meet the preset requirements, cathode tail plates, cathode mounting plates, anode mounting plates and anode tail plates are arranged on the upper and lower parts and pressurized to achieve the preset stacking pressure of the entire large fuel cell stack, and the stack packaging is completed.

[0020] Furthermore, the short stack pre-compression pressure used in the integration method of the present invention is 25-95% of the preset loading pressure of the entire stack.

[0021] Beneficial effects: Compared with the prior art, the significant advantages of the present invention are: the single cell module is applied as a unit module to a large fuel cell stack, which can greatly reduce the number of stacked components and improve the reliability of the stacking process on the one hand; on the other hand, the single cell module is pre-activated before stacking, so that the quality problems of the single cell can be discovered in time at the module stage and replaced, ensuring the consistency of the single cell performance between each module, thereby improving the one-time success rate of the large fuel cell stack, avoiding the side effects of disassembling the problem single cell after stacking, and the single cell module has structural independence, and the traceability code of each module facilitates the process control of production, storage and disassembly.

[0022] In addition, the single cell module of the present invention is connected and fixed by using hollow inserts, which ensures the alignment between the single cells. The hollow inserts using this structure can effectively avoid compression interference of the anchors on the short stack, further improving the reliability and success rate of using the single cell module to stack to form a large fuel cell stack. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] FIG1 is a schematic structural diagram of a single battery module according to the present invention;

[0024] FIG2 is a front view of the hollow insert used in the present invention;

[0025] FIG3 is a cross-sectional view of the hollow insert used in the present invention;

[0026] FIG4 is a schematic structural diagram of a short stack formed by the present invention;

[0027] FIG5 is a process flow chart of integrating 50 groups of single cells into a single cell module according to the present invention. DETAILED DESCRIPTION

[0028] The technical solution of the present invention is further described in detail below with reference to the accompanying drawings.

[0029] The large fuel cell stack of the present invention comprises a plurality of groups of single cell modules, cathode tail plates, cathode mounting plates, single cell modules, anode mounting plates and anode tail plates arranged above and below the plurality of groups of single cell modules.

[0030] As shown in FIG1 , the single cell module of the present invention is composed of a plurality of stacked groups of single cells 1, and the plurality of single cells 1 are connected and fixed by hollow inserts 2. The hollow inserts 2 are located in a socket provided at a location of the single cell module away from the active area and the sealing area. The plurality of single cells 1 are fixed in a module through the provision of the hollow inserts 2.

[0031] As shown in Figures 2 and 3, the hollow insert 2 includes an outer sleeve 3, which fits snugly within the receptacle to align the groups of cells. An inner sleeve 4, cooperating with the outer sleeve 3, and a tensioning member 6, which can be a spring or elastic band, connects the outer and inner sleeves 3 and 4. When a group of cell modules is compressed, the inner sleeve 4 slides within the outer sleeve 3. The length of the outer sleeve 3 and inner sleeve 4 is shorter than the height of the compressed cell modules, ensuring that the hollow insert 2 does not interfere with the compression of the cell modules.

[0032] Because the outer sleeve 3 ensures cell alignment (the inner sleeve 4 has clearance, requiring space for cell module compression), inserts can be used at all four corners of the cell plates and along the edges. Preferably, each cell module is secured with only two hollow inserts 2, allowing for different combinations of hollow inserts 2 for the upper and lower cell modules (e.g., the diagonal intersections of the inserts in the upper cell module correspond to the diagonal intersections of the hollow inserts 2 in the lower cell module). Furthermore, the hollow inserts 2 (sleeve and pins or anchors) employed in the present invention are made of a non-conductive material (e.g., plastic) to prevent electrical shorting of the cells.

[0033] In addition, each end face of the outer sleeve 3 and the inner sleeve 4 has a sleeve cover 5 to respectively fix the top and bottom plates of the single cell module, and connect and fix them via a tensioning member 6. The thickness of the sleeve cover 5 is smaller than that of the single cell plate, so that the sleeve cover 5 does not affect the fit between the upper and lower single cell modules in the stack.

[0034] The hollow insert 2 also includes an anchor 7 configured to cooperate with the tensioning member 6. Preferably, the anchor 7 can be a pin or an anchor. Correspondingly, the outer sleeve 3 and the inner sleeve 4 are each provided with a notch on the sleeve cover 5 for receiving the anchor 7. The outer sleeve 3 and the sleeve cover 5 of the inner sleeve 4 are configured in a male-female docking arrangement, and the end surfaces of the upper and lower plates of the single cell module are configured in a concave-convex docking arrangement, thereby achieving effective docking between multiple single cell modules.

[0035] The method of integrating the above-mentioned large fuel cell stack of the present invention comprises the following steps:

[0036] (1) Stacking several single cells 1 in sequence and connecting and fixing them with hollow inserts to form a single cell module;

[0037] (2) A cathode tail plate 8, a cathode mounting plate 9, an anode mounting plate 10 and an anode tail plate 11 are arranged above and below the single cell module to form a short stack, as shown in FIG4 ;

[0038] (3) Pre-press the short stack, and perform pre-activation and performance testing on the short stack; keep the short stack modules with the single cell consistency performance meeting the standard as standby; detect and remove the problem single cells, and re-stack them for pre-activation and performance testing until the performance of all single cell modules meets the preset requirements;

[0039] (4) After stacking several groups of single cell modules in sequence, cathode tail plates, cathode mounting plates, anode mounting plates and anode tail plates are arranged on the upper and lower sides and pressurized to achieve the preset stacking pressure of the entire large fuel cell stack, and the stack packaging is completed.

[0040] In addition to the above, the single cell modules formed in the present invention can be constructed in groups of 10-100 cells. The resulting short stack pre-compression pressure is 25-95% of the preset loading pressure of the entire stack, preferably 40-60%. The activation process employed in the integration method of the present invention can directly utilize existing activation processes and is not a requirement of this patent application.

[0041] Specifically, the method of integrating 1000 groups of single cells into a large fuel cell stack of the present invention includes the following steps, and the process flow chart is shown in FIG5 :

[0042] (1) preparing 1100 groups of single cells, and stacking 20 groups of single cells in sequence and connecting and fixing them with hollow inserts to form a single cell module consisting of 20 groups of single cells, for a total of 50 groups of single cell modules;

[0043] (2) A cathode tail plate, a cathode mounting plate, an anode mounting plate, and an anode tail plate are arranged above and below the single cell module to form a short stack;

[0044] (3) Pre-press the short stack, and perform pre-activation and performance testing on the short stack; keep the short stack modules with the single cell consistency performance meeting the standard as standby; detect and remove the problem single cells, and re-stack them for pre-activation and performance testing until the performance of all single cell modules meets the preset requirements;

[0045] (4) After stacking 50 groups of single battery modules in sequence, cathode tail plates, cathode mounting plates, anode mounting plates and anode tail plates are arranged on the upper and lower parts thereof and pressurized to achieve the preset stacking pressure of the entire large fuel cell stack, and the stack packaging is completed.

Claims

1. A single battery module, characterized in that: The module is formed by stacking a plurality of groups of single batteries (1), and the plurality of groups of single batteries (1) are connected and fixed by hollow inserts (2); The hollow insert (2) comprises an outer sleeve (3) and an inner sleeve (4) matched with the outer sleeve (3); the end faces of the outer sleeve (3) and the inner sleeve (4) are each provided with a sleeve cover (5) to respectively fix the uppermost and lowermost plates of the single battery module; the inner sleeve (4) is provided with a tensioning member (6) connecting the outer sleeve (3) and the inner sleeve (4); the sleeve covers (5) of the outer sleeve (3) and the inner sleeve (4) are respectively provided with anchors (7) matched with the tensioning member (6).

2. The single battery module according to claim 1, characterized in that: The single cell module is provided with an insertion hole away from the active area and the sealing area, the hollow insert (2) is arranged in the insertion hole, and the thickness of the tube cover (5) of the hollow insert (2) is less than the thickness of the single cell plate.

3. The single battery module according to claim 1, characterized in that: The upper and lower cylinder covers (5) of the hollow insert (2) are matched with each other in a male-female butt joint manner.

4. The single battery module according to claim 2, characterized in that: The outer sleeve (3) of the hollow insert (2) is tightly attached to the insertion hole so that a plurality of groups of single cells (1) are aligned with each other, and the lengths of the outer sleeve (3) and the inner sleeve (4) are shorter than the height of the single cell module after pre-compression.

5. The single battery module according to claim 1, characterized in that: The anchoring member (7) is a pin or an anchor, which is arranged on the cylinder cover (5), and the tensioning member (6) is a spring or an elastic band.

6. The single battery module according to claim 5, characterized in that: The sleeve covers (5) of the outer sleeve (3) and the inner sleeve (4) are provided with notches for accommodating anchoring pieces (7).

7. The single battery module according to claim 1, characterized in that: The upper and lower electrode plate end surfaces of the single battery module are matched in a concave-convex docking manner to achieve docking between a plurality of single battery modules.

8. A large fuel cell stack, characterized in that: The battery stack comprises a plurality of groups of single battery modules as claimed in claim 1, and cathode tail plates, cathode mounting plates, anode mounting plates and anode tail plates arranged above and below the plurality of groups of single battery modules.

9. A method for integrating a large fuel cell stack as claimed in claim 8, characterized in that The steps include: (1) stacking a plurality of groups of single batteries (1) in sequence and connecting and fixing them with a hollow insert (2) to form a single battery module; (2) a cathode tail plate (8), a cathode mounting plate (9), an anode mounting plate (10) and an anode tail plate (11) are arranged above and below the single cell module to form a short stack; (3) Pre-press the short stack, and perform pre-activation and performance testing on the short stack; keep the single cell modules that meet the single cell consistency performance standards as spares; detect and remove the problematic single cells, and re-stack them for pre-activation and performance testing until the performance of all single cell modules meets the preset requirements; (4) After stacking several groups of single battery modules that meet the preset requirements, a cathode tail plate, a cathode mounting plate, an anode mounting plate and an anode tail plate are arranged above and below them and pressurized to achieve the preset stacking pressure of the entire large fuel cell stack, and the stack packaging is completed.

10. The method for integrating a large fuel cell stack according to claim 9, characterized in that: The short stack pre-compression pressure is 25-95% of the preset loading pressure of the whole stack.

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