Preparation process of high-capacity battery

Abstract

The invention relates to the field of batteries, in particular to a preparation process of a high-capacity battery. The problem that an existing large-capacity battery sharing pipeline assembly is difficult to assemble is solved. Comprising the following steps: processing a shell, prefabricating a single battery, loading the prefabricated single battery into a barrel, sealing, unpacking and connecting in parallel. A plurality of single batteries with a sealing assembly are arranged in a cylinder with an electrolyte sharing cavity, the cylinder is sealed by a cover plate, the sealing assembly is opened through an unpacking process, so that the electrolyte sharing cavity is communicated with an electrolyte region of an inner cavity of each single battery, and the electrolyte of each single battery is shared to guarantee the consistency of each single battery; and the cycle life of the high-capacity battery is prolonged to a certain extent. The electrolyte sharing cavity is a first channel located in the barrel, insertion is not needed, and the requirements for machining precision and assembly precision are low; and meanwhile, the assembly process is relatively simple, and the processing difficulty and the processing cost of the large-capacity battery with the sharing system are greatly reduced.

Description

Technical Field

[0001] The present invention relates to the field of batteries, and in particular to a preparation process of a large-capacity battery. Background Art

[0002] Currently, many single cells are connected in parallel or in series on the market to form large-capacity batteries (also called battery modules or battery packs).

[0003] An existing large-capacity battery has a structure such as Figure 1 As shown, it includes a battery pack body formed by a plurality of single cells connected in parallel and a shared pipe assembly located at the bottom of the battery pack body; the shared pipe assembly is used to connect all the inner cavities of the plurality of single cells so that all the single cells in the battery pack are in one electrolyte system. The battery pack can enhance the uniformity of the electrolyte of each single cell in the battery pack through the shared pipe assembly, improve the cycle life, and can also replenish the electrolyte for the battery pack through the shared pipe assembly, thereby extending the service life of the battery pack and improving the safety of the battery pack.

[0004] However, this type of shared pipeline assembly is formed by directly sealing and plugging multiple sections of sub-pipes 01 and intermediate connecting pipes 02 with each other by interference fit; at this time, the multiple sections of sub-pipes 01 are arranged one by one on the lower cover plate 03 of the single battery, and the sub-pipes extend along the arrangement direction of the single battery 1, and are extruded integrally with the lower cover plate 03, and are connected to the opening of the lower cover plate 03.

[0005] During assembly, the two ends of the sub-pipeline 01 are used as connecting ends with the middle connecting tube 02 . When two single cells are connected, one end of the sub-pipeline on the two single cells is squeezed into the two ends of the middle connecting tube 02 .

[0006] The shared pipeline assembly requires that each sub-pipeline 01 and the intermediate connecting pipe 02 be coaxial during the plugging process to achieve effective connection. However, the coaxiality of each sub-pipeline and the intermediate connecting pipe 02 is difficult to ensure due to the following reasons:

[0007] 1) The sub-pipeline and the lower cover are an integrated part. If the position of the sub-pipeline on the lower cover is slightly deviated, or the size of each sub-pipeline is slightly deviated, the coaxiality of each sub-pipeline will deviate when plugged in;

[0008] 2) When the above-mentioned integrated part is welded to the cylinder, due to the difference in the welding process, the position of the sub-pipeline relative to the cylinder may be inconsistent, which may lead to deviation in the coaxiality of each sub-pipeline during plugging;

[0009] 3) This solution requires the use of special tooling during plugging. Due to improper use of the tooling or problems with the operation of the construction personnel, the coaxiality of each sub-pipeline may deviate if it is not careful.

[0010] In addition, when plugging in, the deviation between the sub-pipelines will increase with the increase in the number of plug-ins, resulting in the coaxiality between the sub-pipelines being more difficult to ensure as the number of plug-ins increases; resulting in the assembly process, the yield rate decreases as the number of plug-ins increases.

[0011] In summary, since the sub-pipes of two adjacent single cells are difficult to be coaxial, this solution may cause the sub-pipes to be displaced relative to the lower cover plate, or the lower cover plate to be displaced relative to the cylinder during insertion, thereby causing damage to the battery. Summary of the invention

[0012] The purpose of the present invention is to provide a preparation process for a large-capacity battery, so as to overcome the problem that the existing large-capacity battery shared pipeline components are difficult to assemble.

[0013] The technical solution of the present invention is to provide a preparation process of a large-capacity battery, which is characterized by comprising the following steps:

[0014] Processing shell:

[0015] Processing a cylinder with open ends at both ends; and processing a third through hole corresponding to each single battery pole on the top plate of the cylinder;

[0016] Processing a first cover plate and a third cover plate for covering the open end of the cylinder;

[0017] Installing single battery into cylinder:

[0018] Arrange multiple single cells in the cylinder; make each single cell pole extend out of the corresponding third through hole on the cylinder;

[0019] seal:

[0020] The outer shell area corresponding to each third through hole is fixedly sealed with the corresponding single battery shell; the first cover plate and the third cover plate are respectively sealed and connected to the two opposite open ends of the cylinder;

[0021] Unpacking:

[0022] By using external force or the electrolyte itself, a hole is opened in the shell of the single battery, so that the inner cavity of the electrolyte sharing chamber and the electrolyte area of ​​the inner cavity of each single battery are connected.

[0023] The present invention places a plurality of single cells inside a cylinder having a shared electrolyte chamber, seals the cylinder with a cover plate, and opens holes in the shells of the single cells through an unpacking process, so that the shared electrolyte chamber and the electrolyte areas in the inner cavities of each single cell are connected, and the electrolytes of each single cell are shared to ensure the consistency of each single cell, that is, the electrolyte chambers of each single cell are connected so that the electrolytes of all the single cells are in the same system, thereby reducing the differences between the electrolytes of each single cell, improving the consistency between the single cells to a certain extent, and thus improving the cycle life of the large-capacity battery to a certain extent.

[0024] The electrolyte sharing chamber of the present invention is the first channel located in the cylinder, which does not need to be plugged in. In the arrangement direction of the single battery cells, there is no need to consider the coaxial plugging problem, and the requirements for processing accuracy and assembly accuracy are relatively low. At the same time, no special tooling is required, and the assembly process is relatively simple, which greatly reduces the processing difficulty and processing cost of such large-capacity batteries with a shared system, and can realize mass production.

[0025] In addition, the poles of each single battery of the present invention extend out of the top of the shell (in order to ensure the sealing of the entire shell, the gap between the pole and the shell needs to be sealed). Compared with the structure in which the pole is located inside the shell, the pole has a better heat dissipation effect; in addition, when the pole extends out of the shell, if the battery temperature is too high, it is also convenient to use heat exchange equipment to timely remove the heat of the pole, so as to ensure that such large-capacity batteries operate at the optimal temperature.

[0026] In addition, compared with the existing battery module manufacturing process, the large-capacity battery manufacturing process of the present invention requires the operation of capacity sorting and sorting each single battery in order to maintain the consistency of multiple single batteries in the initial state of the battery module.

[0027] In the present invention, multiple single cells are directly installed in a sealed housing, and the multiple single cells are in a unified electrolyte system (equivalent to multiple single cells forming a large-capacity battery cell), which reduces the differences between the single cells. Therefore, the production process of the large-capacity battery can omit the work of capacity separation and sorting, thereby improving the cycle life of the large-capacity battery and also improving the production efficiency of the large-capacity battery.

[0028] In order to further optimize the performance of the above large-capacity battery, the unpacking steps also include:

[0029] By using external force or the electrolyte itself, a hole is opened in the single cell shell, so that the inner cavity of the gas chamber and the gas area of ​​the inner cavity of each single cell are connected.

[0030] The present invention forms a second channel in the cylinder as a gas chamber; during the unpacking process, a hole is opened in the single cell shell so that the gas area in the inner cavity of each single cell is connected with the gas chamber, thereby connecting the gas paths of each single cell. The gases of all the single cells are in the same environment to achieve gas balance, reduce the differences between the single cells, improve the consistency between the single cells, and further improve the cycle life of the large-capacity battery.

[0031] In order to further reduce the differences between the individual single cells, in the step of loading the single cells into the barrel, a plurality of single cells that have been sorted by capacity are arranged in the barrel.

[0032] The first channel of the present invention can be formed in the cylinder in two ways, and the second channel is preferably formed in the cylinder in one way:

[0033] The first forming method of the first channel is similar to the forming method of the second channel, and both can be formed integrally with the cylinder with open ends by using an aluminum extrusion process. Then, accordingly, in the above-mentioned step of processing the shell, the cylinder with open ends can be formed integrally by using an aluminum extrusion process, and the first channel and the second channel can be formed integrally at the same time, serving as the electrolyte shared chamber and the gas chamber, respectively.

[0034] Corresponding to the first channel formed by aluminum extrusion process, in order to ensure that the pole of each single battery can extend out of the corresponding third through hole, multiple single batteries can be loaded into the cylinder in the following three ways:

[0035] Method 1:

[0036] Fix multiple single batteries into a whole and push them into the inner cavity of the cylinder from any open end of the cylinder;

[0037] Using a lifting tool to support multiple single cells from the bottom, so that the bottom of each single cell is separated from the bottom of the cylinder, and the pole of each single cell extends out of the corresponding third through hole;

[0038] Insert the second long supporting ribs of equal height along the length direction of the cylinder, and then take out the lifting tooling.

[0039] Method 2:

[0040] Push multiple single cells into the inner cavity of the cylinder from any open end of the cylinder in turn, and push each single cell into place;

[0041] Each pad is inserted between the bottom of the cylinder and the bottom of the cylinder to ensure that the pole of the single battery is fully extended out of the corresponding third through hole.

[0042] Method 3:

[0043] Turn the cylinder over so that the top of the cylinder faces downward, fix multiple single batteries as a whole, and push them into the inner cavity of the cylinder from any open end of the cylinder; or push multiple single batteries into the inner cavity of the cylinder from any open end of the cylinder in sequence;

[0044] Under the action of gravity, the pole of each single battery extends out of the corresponding third through hole, and the second supporting rib is inserted between the bottom of each single battery and the bottom of the cylinder; the cylinder is turned over so that the top of the cylinder faces upward.

[0045] The second molding method of the first channel is different from the first molding method. It is formed during the process of loading the single battery into the cylinder. Specifically, the following three methods can be used:

[0046] Method 1:

[0047] Fix multiple single cells as a whole, and push them into the inner cavity of the cylinder from any open end of the cylinder; use a lifting tool to support multiple single cells from the bottom, so that the bottom of each single cell is separated from the bottom of the cylinder, and the pole of each single cell extends out of the corresponding third through hole;

[0048] At least two first supporting ribs are inserted between the bottom of each single cell and the bottom of the cylinder along the length direction of the cylinder to form a first channel as a shared electrolyte chamber and ensure that the pole of each single cell extends out of the corresponding third through hole;

[0049] Take out the lifting tool.

[0050] Method 2:

[0051] Push multiple single cells into the inner cavity of the cylinder from any open end of the cylinder in turn. After each single cell is pushed into place, insert each pad between its bottom and the bottom of the cylinder to form an electrolyte sharing chamber while ensuring that the pole of the single cell is fully extended out of the corresponding third through hole.

[0052] Method 3:

[0053] Turn the cylinder over so that the top of the cylinder faces downward, fix multiple single batteries as a whole, and push them into the inner cavity of the cylinder from any open end of the cylinder; or push multiple single batteries into the inner cavity of the cylinder from any open end of the cylinder in sequence;

[0054] Under the action of gravity, the pole of each single battery extends out of the corresponding third through hole, and at least two first supporting ribs are inserted between the bottom of each single battery and the bottom of the cylinder to form an electrolyte sharing chamber;

[0055] Turn the cylinder over so the top of the cylinder is facing up.

[0056] Furthermore, in order to form a more complete SEI film and make the large-capacity battery have a more stable cycle capacity, during the unpacking process, a hole is opened in the single cell shell by using external force or the electrolyte itself, and after the inner cavity of the electrolyte shared chamber and the electrolyte area of ​​the inner cavity of each single cell are connected, it also includes the step of injecting electrolyte into the inner cavity of each single cell through the electrolyte shared chamber to form the entire large-capacity battery.

[0057] The beneficial effects of the present invention are:

[0058] The present invention places a plurality of capacity-divided and sorted single cells with a sealing assembly inside a cylinder with a shared electrolyte chamber, seals the cylinder with a cover plate, and opens holes in the shell of the single cells through an unpacking process, so that the shared electrolyte chamber and the electrolyte areas of the inner cavities of each single cell are connected, and the electrolytes of each single cell are shared to ensure the consistency of each single cell, that is, the electrolyte chambers of each single cell are connected so that the electrolytes of all the single cells are in the same system, thereby reducing the differences between the electrolytes of each single cell, improving the consistency between the single cells to a certain extent, and thus improving the cycle life of the large-capacity battery to a certain extent.

[0059] The electrolyte shared chamber of the present invention does not need to be plugged in, and there is no need to consider the coaxial plugging problem in the arrangement direction of the single battery cells, and the requirements for processing accuracy and assembly accuracy are relatively low. At the same time, no special tooling is required, and the assembly process is relatively simple, which greatly reduces the processing difficulty and processing cost of such large-capacity batteries with a shared system, and can realize mass production.

[0060] In addition, the poles of each single battery of the present invention extend out of the top of the shell (in order to ensure the sealing of the entire shell, the gap between the pole and the shell needs to be sealed). Compared with the structure in which the pole is located inside the shell, the pole has a better heat dissipation effect; in addition, when the pole extends out of the shell, if the battery temperature is too high, it is also convenient to use heat exchange equipment to timely remove the heat of the pole, so as to ensure that such large-capacity batteries operate at the optimal temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 It is a schematic diagram of the structure of a large-capacity battery in the background technology;

[0062] Figure 2 This is a schematic diagram of the structure of a large-capacity battery after the outer shell is removed in Example 1;

[0063] Figure 3 This is a schematic diagram of the structure of a large-capacity battery in Example 1;

[0064] Figure 4 This is a schematic diagram of the structure of a commercially available square shell battery in Example 1;

[0065] Figure 5This is a schematic diagram of an electrolyte sharing chamber structure in Example 1;

[0066] Figure 6 This is a schematic diagram of another electrolyte sharing chamber structure in Example 1;

[0067] Figure 7 This is a schematic diagram of the third electrolyte sharing chamber structure in Example 1;

[0068] Figure 8 This is a schematic diagram of the structure of the third cover plate in Example 1;

[0069] Fig. 9 This is a schematic diagram of the structure of a large-capacity battery with a heat transfer connector in Example 1;

[0070] Fig.10 is a schematic structural diagram of the heat transfer connector in Example 1;

[0071] Fig.11 This is a schematic diagram of the structure of a large-capacity battery in Example 2;

[0072] Fig.12 This is a schematic diagram of the structure of the third cover plate in Example 2;

[0073] Fig.13 This is a schematic diagram of a cylinder structure in Example 3;

[0074] Fig.14 This is another schematic diagram of the cylinder structure in Example 3;

[0075] Fig.15 This is a schematic diagram of the structure in which a partition is added to the inner cavity of the U-shaped shell in Example 4;

[0076] Fig.16 This is a schematic diagram of the structure of the I-shaped separator and the single battery in Example 4;

[0077] The accompanying drawings in the figure are marked as follows:

[0078] 01. Sub-pipeline; 02. Intermediate connecting pipe; 03. Lower cover plate;

[0079] 1. Single cell; 2. U-shaped shell; 3. First cover plate; 4. Third cover plate; 5. Second cover plate; 6. Bottom of U-shaped shell; 7. Pipe section; 8. First channel; 9. Fin; 10. First supporting rib; 11. Liquid injection port; 12. Third through hole; 13. Second channel; 15. Weak part; 16. Partition; 17. Vertical beam; 18. Horizontal beam; 19. Heat transfer connector. DETAILED DESCRIPTION

[0080] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0081] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0082] In the description of the present invention, it should be noted that the orientations or positional relationships indicated by the terms "top, bottom" and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first, second, third, fourth, etc." are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0083] For the convenience of description, in the following embodiments, the length direction of the shell is defined as the x direction, the width direction of the shell is defined as the y direction, and the height direction of the shell is defined as the z direction.

[0084] Example 1

[0085] like Figure 2 and Figure 3 As shown, the large-capacity battery of this embodiment includes 9 single cells 1 connected in parallel. The number of single cells 1 in other embodiments can be adjusted according to actual needs. Figure 4 The single cell 1 is a square shell battery, which includes an upper cover plate, a lower cover plate, a cylinder and a battery cell assembly; the battery cell assembly here can also be called an electrode assembly, which is composed of a positive electrode, a diaphragm and a negative electrode arranged in sequence and assembled by a lamination or winding process. The upper cover plate, the cylinder and the lower cover plate constitute the shell of the single cell 1, and the battery cell assembly is arranged in the shell of the single cell 1.

[0086] The bottom of the shell of each single battery 1 is provided with a first through hole penetrating the inner cavity thereof;

[0087] Combination Figure 3 The housing of this embodiment includes a U-shaped shell 2, a first cover plate 3, a third cover plate 4 and a second cover plate 5; wherein the U-shaped shell 2 and the second cover plate 5 are separately arranged.

[0088] The bottom 6 of the U-shaped housing is provided with an electrolyte sharing chamber extending along the x direction;

[0089] The electrolyte sharing chamber can adopt the following structural forms:

[0090] The first structure, such as Figure 5 As shown, a pipe section 7 with a square or circular cross-section is fixed on the outer surface of the bottom 6 of the U-shaped shell; through holes are opened in the pipe wall and the bottom 6 of the U-shaped shell; the through holes can be multiple, corresponding to and penetrating the first through holes of each single battery; or it can be a long strip through hole that penetrates the first through holes of all single batteries.

[0091] The second structure, such as Figure 6 and Figure 7 As shown, a first channel 8 extending along the x direction is provided at the bottom 6 of the U-shaped shell, and the first channel 8 is directly connected to the first through hole of each single battery 1; compared with the first structure that requires a separate pipe segment and requires through holes to be opened on the bottom 6 of the U-shaped shell and the pipe segment, the second structure is relatively simple to process and manufacture.

[0092] The second structure can be implemented in the following two ways:

[0093] Method 1: Figure 6 As shown, the first channel 8 can be formed directly on the bottom 6 of the U-shaped shell by bending, stamping, die-casting or aluminum extrusion technology, and the inner surface of the bottom 6 of the U-shaped shell is raised in a direction away from the top of the U-shaped shell 2.

[0094] In order to achieve effective heat dissipation, heat dissipation fins 9 extending along the x direction are arranged on the outer surface of the U-shaped shell bottom 6 and on both sides of the first channel 8. The heat generated during the operation of the large-capacity battery can be dissipated in time through the fins 9.

[0095] Method 2: Figure 7 As shown, at least two first support ribs 10 extending in the x direction are provided on the inner surface of the U-shaped housing bottom 6 , and the two first support ribs 10 and the region of the U-shaped housing bottom 6 between the two first support ribs 10 form a first channel 8 .

[0096] use Figure 7 The electrolyte shared chamber structure shown can ensure the structural regularity of the entire large-capacity battery. As above, on the one hand, it is easy to ensure the density of the energy storage device when integrating the energy storage device based on such large-capacity batteries; on the other hand, it can be treated as a whole and coated with an insulating film (also called blue film or protective film) on the outside to improve the overall safety performance of such large-capacity batteries.

[0097] Figure 6 and Figure 7The first channel 8 in the figure has open ends at both ends located in the yz plane, and the openings at both ends are subsequently sealed by the first cover plate 3 and the third cover plate 4; in other embodiments, the first channel 8 can also be directly closed at both ends located in the yz plane, but the molding method is relatively complicated.

[0098] In this embodiment, a liquid injection port 11 may be provided in the first channel 8 (see Figure 3 ), when the inner cavity of each single cell 1 and the electrolyte shared chamber are connected, the electrolyte can be injected into the inner cavity of each single cell 1 and the electrolyte shared chamber again through the injection port 11 to ensure the continuity of the electrolyte, and the electrolyte can be replaced later through the injection port 11.

[0099] It should be noted that, when no liquid is injected, the liquid injection port 11 needs to be sealed by a plug.

[0100] The third structure uses the gap between the inner surface of the U-shaped shell bottom 6 and the outer surface of the lower cover plate of each single cell as a shared electrolyte chamber. If this structure is adopted, an auxiliary structure is required to improve the stability of each single cell in the shell.

[0101] The structure of the second cover plate 5 in this embodiment is as follows Figure 8 As shown, the second cover plate 5 is provided with a third through hole 12 through which the pole of each single battery 1 can be extended; the second cover plate 5 covers the top open end of the U-shaped shell 2 and is sealed with the open end; after the pole of each single battery 1 extends out of the third through hole 12, the outer shell area corresponding to the third through hole 12 is fixedly sealed with the single battery shell. The edge of the third through hole 12 can be welded to the single battery shell in the area surrounding the pole to achieve sealing;

[0102] If the sizes of the single cells 1 along the z direction are not completely equal, the shells of some single cells 1 with smaller sizes in the z direction may have problems with poor welding or even be unable to be welded to the large-capacity battery shell, making it difficult to ensure the sealing of the third through hole 12 and the single cell shell.

[0103] In order to overcome such problems, a weak portion 15 may be provided in the peripheral area of ​​the third through hole 12. During the welding process, the deformation of the weak portion 15 compensates for the size difference of each single battery in the z direction, so that the poles of all single batteries 1 extend out of the third through hole 12. The weak portion 15 in this embodiment may be an annular groove with the center of the third through hole 12 as the center point and opened along the peripheral area of ​​the third through hole 12. In other embodiments, the weak portion 15 may also be a long strip groove opened in the peripheral area of ​​the third through hole 12. In other embodiments, if there is a similar problem, that is, the poles of all single batteries 1 cannot fully extend out of the third through hole 12 at the same time, the solution may be to add a weak portion 15 in the peripheral area of ​​the third through hole 12.

[0104] A sealing connector may also be provided between the third through hole 12 and the pole, the sealing connector comprising a hollow member; the bottom of the hollow member is used to be sealed and connected to the first area of ​​the single cell, and the top of the hollow member is sealed and connected to the second area of ​​the shell; the first area is the area around any pole in the upper cover of any single cell; the second area is the area corresponding to any third through hole on the shell. The area corresponding to the third through hole is the surrounding area on the outer surface of the shell corresponding to any third through hole; or the area corresponding to the third through hole is the wall of the third through hole. The area around the pole is the area around the insulating seal on the pole. The insulating seal is a part on the single cell used to insulate the pole from the upper cover.

[0105] The shape of the second cover plate 5 is adapted to the shape of the top open end of the U-shaped shell 2. In this embodiment, it is a square shell, so the flat plate is a square flat plate, and its area can be slightly larger than the area of ​​the top open end of the U-shaped shell 2, and it is fixed to the top open end of the U-shaped shell 2 by fusion welding; the area can also be slightly smaller than the area of ​​the top open end of the U-shaped shell 2, and it is fixed to the top open end of the U-shaped shell 2 by embedding welding.

[0106] The large-capacity battery of this embodiment can be prepared by the following process:

[0107] Step 1: Processing the U-shaped shell 2, the first cover plate 3, the third cover plate 4 and the second cover plate 5.

[0108] Step 2: sorting by capacity, screening multiple single cells that meet the requirements; opening a first through hole at the bottom of the single cell housing and sealing it with a sealing assembly; arranging the single cells with the sealing assembly at the first through hole in the U-shaped housing 2 of step 1, the sealing assembly of each single cell corresponding to the first channel 8, to ensure that after the sealing assembly is opened by external force or the electrolyte itself, the electrolyte area of ​​the inner cavity of each single cell is connected with the first channel 8; the sealing assembly can adopt the sealing assembly disclosed in Chinese patents CN218525645U and CN218525614U.

[0109] Step 3: seal and weld the second cover plate 5 to the open end at the top of the U-shaped shell 2, weld the third through hole 12 to the peripheral part of the single cell shell pole, and weld the first cover plate 3 and the third cover plate 4 to the other two opposite open ends of the U-shaped shell 2 to achieve sealing. It should be noted here that the first cover plate 3 and the third cover plate 4 need to seal the two open ends of the first channel 8 located in the yz plane at the same time. The first cover plate, the second cover plate and the third cover plate can also be fixed to the open end of the U-shaped shell 2 by screw fastening or gluing, but compared with the welding method, the sealing or connection reliability is relatively weak.

[0110] Step 4: Use external force or the electrolyte itself to open the sealing component, so that the inner cavity of the first channel 8 and the electrolyte area of ​​each single battery cavity are connected.

[0111] After the inner cavity of each single battery 1 and the first channel 8 are connected, the electrolyte in the inner cavity of each single battery 1 is connected through the first channel 8. In order to prevent the interruption of the electrolyte, the electrolyte can be injected into the first channel 8 to ensure the continuity of the electrolyte after the inner cavity of each single battery 1 and the first channel 8 are connected.

[0112] Then all the single cells 1 are connected in parallel. Fig. 9 and Fig.10 The heat transfer connector shown connects all the single cells 1 in parallel. The heat transfer connector is a slender member used to connect to the positive or negative electrode of each single cell; and a clamping portion for installing a heat transfer tube is provided on the slender member along the axial direction. By connecting the positive or negative electrodes of multiple single cells through the heat transfer connector and clamping the heat transfer tube on the heat transfer connector, the local temperature of the pole on each single cell can be controlled, greatly reducing the occurrence of thermal runaway caused by excessive pole temperature.

[0113] In order to form a more complete SEI film and make the large-capacity battery have a more stable cycle capacity, the electrolyte can be injected into the inner cavity of each single battery 1 through the first channel 8, and then the entire large-capacity battery is formed.

[0114] Example 2

[0115] Different from the large-capacity battery in embodiment 1, this embodiment adds a gas chamber on the second cover plate 5 as a gas sharing chamber or explosion relief channel. Fig.11 As shown, Fig.11 The first channel 8 adopts Figure 7 The structure shown in FIG. 1 , of course, the first channel 8 can also be used Figure 6 The structure shown.

[0116] The gas chamber can adopt the following structural forms:

[0117] 1. A pipe section with a square or circular cross section is fixed on the outer surface of the top of the second cover plate 5; through holes are opened in the pipe wall and the second cover plate 5;

[0118] Second, the gap between the inner surface of the second cover plate 5 and the outer surface of the upper cover plate of each single battery cell is used as a gas chamber.

[0119] 3. Fig.12 As shown, a second channel 13 extending along the x direction is provided on the second cover plate 5; this structure is simpler than the first structure, and each single cell has higher stability in the housing than the second structure.

[0120] The second channel 13 may be formed directly on the second cover plate 5 by using a bending or aluminum extrusion process, wherein the second channel 13 protrudes in a direction away from the U-shaped housing bottom 6 .

[0121] When the second channel 13 is used as a gas sharing chamber, a fifth through hole penetrating the inner cavity of each single cell 1 needs to be opened on the top of the shell of each single cell 1, and the second channel 13 is connected with the fifth through hole, and the second channel 13 is connected with the gas area of ​​the inner cavity of each single cell 1 through the fifth through hole. In other embodiments, the second cover plate 5 and the open end at the top of the U-shaped shell 2 can also be fixed by bonding or screw connection, but the sealing or connection reliability is relatively weak compared to the welding method. It should be noted that during operation, the openings at both ends of the second channel 13 (the open ends parallel to the yz plane) need to be blocked to prevent the external environment from affecting the electrolyte in the inner cavity of each single cell.

[0122] In this embodiment, an exhaust valve and an explosion-proof membrane are arranged on the second channel 13, or only an exhaust valve is arranged; the exhaust valve can be opened manually or automatically, and the exhaust valve is opened regularly, and the gas in the gas zone of each single battery 1 can be discharged through the second channel 13 and the exhaust valve; when the explosion-proof membrane is arranged, the exhaust valve and the explosion-proof membrane are located at both ends of the second channel 13, and the explosion-proof membrane is used for when any single battery 1 has thermal runaway, the thermal runaway smoke breaks through the explosion-proof membrane and is discharged from the second channel 13, so that this type of large-capacity battery has higher safety performance.

[0123] It can be prepared by the following process:

[0124] It is necessary to open a fifth through hole on the top of each single cell and seal it with a sealing component on the basis of the preparation process of Example 1; arrange multiple single cells with sealing components at the fifth through holes in the U-shaped shell 2; seal and weld the second cover plate 5 to the open end of the top of the U-shaped shell 2, so that the fifth through hole with the sealing component corresponds to the second channel 13, and ensure that after the sealing component is opened by external force or the electrolyte itself, the fifth through hole and the second channel 13 are connected; the sealing component can adopt the sealing component disclosed in Chinese patents CN218525645U and CN218525614U, weld the third through hole 12 and the peripheral part of the single cell shell pole to achieve sealing. Finally, the sealing component is opened by external force or the electrolyte itself, and the inner cavity of the second channel 13 is connected with the gas area of ​​the inner cavity of each single cell.

[0125] When the second channel 13 is used as an explosion relief channel, the second channel 13 covers the explosion relief portion on the top of each single battery 1. When the explosion relief portion of any single battery 1 is broken by the internal smoke, the gas area in the internal cavity of the single battery 1 is connected with the internal cavity of the second channel 13.

[0126] It can be prepared by the following process:

[0127] On the basis of the preparation process of Example 1, it is necessary to seal and weld the second cover plate 5 to the open end at the top of the U-shaped shell 2, so that the explosion venting part of each single cell corresponds to the second channel 13, ensuring that after the explosion venting part is broken by the inner cavity flue gas, the explosion venting part and the second channel 13 are connected; weld the third through hole 12 to the surrounding part of the single cell shell pole to achieve sealing.

[0128] It should be noted that the explosion venting part described in this embodiment includes an explosion venting opening or explosion-proof opening with an explosion venting membrane disposed on the top of the single battery 1 .

[0129] Example 3

[0130] Different from the above-mentioned embodiment, the U-shaped housing 2 and the second cover plate 5 in this embodiment are integrated. Fig.13 and Fig.14 The second cover plate 5 may or may not be provided with a gas chamber, and the following description is made taking the case where a gas chamber is provided as an example:

[0131] It can be understood that the housing of this embodiment includes Fig.13 or Fig.14 The cylinder shown in FIG. 1 and the first cover plate 3 and the third cover plate 4 for covering the two opposite open ends of the cylinder; the first cover plate 3 and the third cover plate 4 are located in the yz plane. Similarly, it should be noted here that the first cover plate 3 and the third cover plate 4 need to cover the two opposite open ends of the sealed cylinder while covering the two opposite open ends of the sealed first channel 8 and the second channel 13.

[0132] The cylinder of this embodiment can be integrally formed by aluminum extrusion process; because the cylinder extends along the x direction, its open end is located in the yz plane, and the extrusion direction is along the x direction, therefore, the cylinder that meets the target length can be extruded in one time.

[0133] It should be noted that: in the extrusion Fig.13 When the cylinder shown in the figure is formed, it is not necessary to form the first channel 8 at the same time, that is, the first support rib 10 and the cylinder need to be separately arranged; Fig.14 When the cylinder is shown, the first channel 8 needs to be formed at the same time.

[0134] The large capacity battery of this embodiment can be prepared by the following process: Fig.14 Take the structure shown as an example:

[0135] Step 1: Processing the shell:

[0136] The cylinder, the first cover plate 3 and the third cover plate 4 are processed.

[0137] Step 2: Prefabricate single cells:

[0138] Capacity sorting, screening multiple single cells that meet the requirements; opening a first through hole at the bottom of the single cell housing and sealing it with a sealing assembly; opening a fifth through hole at the top of the single cell housing and sealing it with a sealing assembly;

[0139] Step 3: Prefabricated single cells are loaded into the cylinder:

[0140] Arrange multiple single cells with sealing components in the cylinder of step 1; make the first through hole with sealing components correspond to the first channel 8, and the fifth through hole with sealing components correspond to the second channel 13, and ensure that after the sealing components are opened by external force or electrolyte itself, the first through hole is connected to the first channel 8, and the fifth through hole is connected to the second channel 13; the sealing components can adopt the sealing components disclosed in Chinese patents CN218525645U and CN218525614U. The poles of each single cell 1 extend out of the corresponding third through hole 12 on the second cover plate 5.

[0141] Step 4: Sealing:

[0142] The third through hole 12 is welded to the peripheral part of the single cell housing pole to achieve sealing; it should be noted here that in order for each single cell 1 to be smoothly arranged in Fig.14 In the cylinder shown, the minimum dimension of the cylinder along the z direction needs to be larger than the dimension of the single battery 1 along the z direction. At the same time, in order to ensure that the pole of each single battery 1 can extend out of the third through hole 12 at the top of the cylinder, a second supporting rib needs to be added at the bottom of each single battery 1;

[0143] The plurality of single cells with sealing components can be arranged in the cylinder of step 1 in the following three ways:

[0144] 1) Use long strip-shaped equal-height second support ribs;

[0145] Fix multiple single cells 1 as a whole, and push them into the inner cavity of the cylinder from any open end of the cylinder; at this time, the bottom of each single cell 1 contacts the bottom of the cylinder, and the pole of each single cell 1 corresponds to the corresponding third through hole 12, but does not extend out of the third through hole 12; then use a lifting tool to support the multiple single cells 1 from the bottom, so that the bottom of each single cell 1 is separated from the bottom of the cylinder, and the pole of each single cell 1 extends out of the corresponding third through hole 12; then, insert a long strip of equal-height second supporting ribs along the x direction, and take out the lifting tool.

[0146] It should be noted that in the z direction, the size of the long strip-shaped second support ribs of equal height must meet the following requirements: after the second support ribs are added between the bottom of each single battery 1 and the bottom of the cylinder, the pole of each single battery 1 extends out of the corresponding third through hole 12.

[0147] 2) Select multiple pads corresponding to the single cells 1 to form the second supporting ribs;

[0148] Push multiple single cells 1 into the inner cavity of the cylinder from any open end of the cylinder in turn. After each single cell 1 is pushed into place, it is necessary to insert each pad between its bottom and the bottom of the cylinder to ensure that the pole of the single cell 1 is fully extended out of the corresponding third through hole 12. In most cases, the pads corresponding to each single cell in this way have different sizes in the z direction.

[0149] 3) Each single battery 1 is pushed upside down into the inner cavity of the cylinder;

[0150] The cylinder is turned over so that the top of the cylinder faces downward, multiple single cells 1 are fixed as a whole, and pushed into the inner cavity of the cylinder from any open end of the cylinder; or multiple single cells 1 are pushed into the inner cavity of the cylinder from any open end of the cylinder in sequence; under the action of gravity, the pole of each single cell 1 extends out of the corresponding third through hole 12, and the second supporting rib is inserted between the bottom of each single cell 1 and the bottom of the cylinder; the cylinder is turned over so that the top of the cylinder faces upward.

[0151] The first cover plate 3 and the third cover plate 4 are welded to the other two opposite open ends of the U-shaped shell 2 .

[0152] Step 5: Unpacking:

[0153] The sealing assembly is opened by external force or the electrolyte itself, so that the inner cavity of the first channel 8 and the electrolyte area of ​​each single battery are connected, and the inner cavity of the second channel 13 and the gas area of ​​each single battery are connected.

[0154] After the inner cavity of each single battery 1 and the first channel 8 are connected, the electrolyte in the inner cavity of each single battery 1 is connected through the first channel 8. In order to prevent the interruption of the electrolyte, the electrolyte can be injected into the first channel 8 to ensure the continuity of the electrolyte after the inner cavity of each single battery 1 and the first channel 8 are connected.

[0155] Then all the single cells 1 are connected in parallel.

[0156] In order to form a more complete SEI film and make the large-capacity battery have a more stable cycle capacity, after the electrolyte is injected into the inner cavity of each single battery 1 through the first channel 8, the entire large-capacity battery is formed.

[0157] If the gas chamber is used as the explosion relief channel, the following steps are different from the above steps:

[0158] In the above steps, there is no need to open a fifth through hole on the top of the single cell shell; multiple single cells with sealing components at the first through holes are arranged in the cylinder of step one; the first through hole with the sealing component corresponds to the first channel 8, ensuring that after the sealing component is opened by external force or the electrolyte itself, the first through hole is connected to the first channel 8, and the explosion venting part on the top of each single cell corresponds to the second channel 13, ensuring that after the explosion venting part is broken by the inner cavity smoke, the explosion venting part is connected to the second channel 13.

[0159] The sealing assembly is opened by external force or the electrolyte itself, and the inner cavity of the first channel 8 and the electrolyte area of ​​the inner cavity of each single battery are connected.

[0160] If adopted Fig.13 The cylinder shown in FIG. arranges a plurality of single cells with sealing components in Fig.13 After the cylinder is inserted, the first support rib 10 is inserted between the bottom of each single battery and the bottom of the cylinder to form the first channel 8, which can support each single battery so that the pole of each single battery 1 can extend out of the third through hole 12 at the top of the cylinder. The same three methods as above can also be used to arrange multiple single batteries with sealing components in Fig.13 In the cylinder shown in the figure, it is only necessary to replace the second supporting ribs with the first supporting ribs 10 .

[0161] The specific steps may include:

[0162] Step 1: Processing the cylinder, the first cover plate 3 and the third cover plate 4.

[0163] Step 2: sorting by capacity, screening multiple single cells that meet the requirements; opening a first through hole at the bottom of the single cell housing and sealing it with a sealing assembly; opening a fifth through hole at the top of the single cell housing and sealing it with a sealing assembly;

[0164] Arrange a plurality of single cells with sealing components in the cylinder body of step 1; insert a first supporting rib 10 between the bottom of each single cell and the bottom of the cylinder body to form a first channel 8;

[0165] The first through hole with the sealing component corresponds to the first channel 8, and the fifth through hole with the sealing component corresponds to the second channel 13, ensuring that after the sealing component is opened by external force or the electrolyte itself, the first through hole is connected to the first channel 8, and the fifth through hole is connected to the second channel 13; the sealing component can adopt the sealing components disclosed in Chinese patents CN218525645U and CN218525614U.

[0166] The poles of each single battery 1 are extended out of the corresponding third through holes 12 on the second cover plate 5, and the third through holes 12 are welded to the surrounding parts of the poles of the single battery housing to achieve sealing;

[0167] The plurality of single cells with sealing components can be arranged in the cylinder of step 1 in the following three ways:

[0168] 1) Use long strip-shaped equal-height first support ribs;

[0169] Fix multiple single cells 1 as a whole, and push them into the inner cavity of the cylinder from any open end of the cylinder; at this time, the bottom of each single cell 1 contacts the bottom of the cylinder, and the pole of each single cell 1 corresponds to the corresponding third through hole 12, but does not extend out of the third through hole 12; then use a lifting tool to support the multiple single cells 1 from the bottom, so that the bottom of each single cell 1 is separated from the bottom of the cylinder, and the pole of each single cell 1 extends out of the corresponding third through hole 12; then, insert at least two long strips of equal-height first supporting ribs along the x direction, and the two first supporting ribs 10 and the bottom area of ​​the cylinder located between the two first supporting ribs 10 form a first channel 8, and then take out the lifting tool.

[0170] It should be noted that in the z direction, the size of the long and equal-height first supporting ribs must meet the following requirements: after the first supporting ribs are added between the bottom of each single battery 1 and the bottom of the cylinder, the pole of each single battery 1 extends out of the corresponding third through hole 12.

[0171] 2) Select multiple pads corresponding to the single cells 1 to form the first supporting ribs;

[0172] Push multiple single cells 1 into the inner cavity of the cylinder from any open end of the cylinder in turn. After each single cell 1 is pushed into place, it is necessary to insert each pad between its bottom and the bottom of the cylinder to ensure that the pole of the single cell 1 is fully extended out of the corresponding third through hole 12. In most cases, the pads corresponding to each single cell in this way have different sizes in the z direction.

[0173] 3) Each single battery 1 is pushed upside down into the inner cavity of the cylinder;

[0174] The cylinder is turned over so that the top of the cylinder faces downward, multiple single cells 1 are fixed as a whole, and pushed into the inner cavity of the cylinder from any open end of the cylinder; or multiple single cells 1 are pushed into the inner cavity of the cylinder from any open end of the cylinder in sequence; under the action of gravity, the pole of each single cell 1 extends out of the corresponding third through hole 12, and the first supporting rib is inserted between the bottom of each single cell 1 and the bottom of the cylinder; the cylinder is turned over so that the top of the cylinder faces upward.

[0175] Step 3: Weld the first cover plate 3 and the third cover plate 4 to the other two opposite open ends of the U-shaped shell 2.

[0176] Step 4: Use external force or the electrolyte itself to open the sealing assembly, so that the inner cavity of the first channel 8 and the electrolyte area of ​​each single battery are connected, and the inner cavity of the second channel 13 and the gas area of ​​each single battery are connected.

[0177] After the inner cavity of each single battery 1 and the first channel 8 are connected, the electrolyte in the inner cavity of each single battery 1 is connected through the first channel 8. In order to prevent the interruption of the electrolyte, the electrolyte can be injected into the first channel 8 to ensure the continuity of the electrolyte after the inner cavity of each single battery 1 and the first channel 8 are connected.

[0178] Then all the single cells 1 are connected in parallel.

[0179] Example 4

[0180] In this embodiment, on the basis of the above-mentioned embodiment, a plurality of partitions 16 are added to the inner cavity of the U-shaped shell 2 or the inner cavity of the cylinder to divide the inner cavity of the U-shaped shell 2 or the inner cavity of the cylinder into a plurality of single battery 1 installation cavities. Fig.15 and Fig.16 ; The partition 16 can be a flat plate, or it can be used as Fig.16 The I-shaped partition shown, the vertical beam 17 of the I-shaped partition is parallel to the first cover plate 3 and the third cover plate 4, and contacts the side walls of the two single cells 1 adjacent to each other and located in the yz plane, one cross beam 18 of the I-shaped partition contacts the side walls of the two single cells 1 located in the xz plane, and another cross beam 18 of the I-shaped partition contacts the other side walls of the two single cells 1 located in the xz plane. The stability of each single cell 1 in the single cell 1 installation cavity can be improved by adding an I-shaped partition.

[0181] In this embodiment, a single cell 1 is fixed in each single cell 1 installation cavity. Each single cell 1 near the middle part has side walls on both sides in contact with the partition 16. One side wall of the two single cells 1 near the outermost part is in contact with the partition 16, and the other side wall is in contact with the first cover plate 3 or the third cover plate 4. On the first hand, the installation stability of each single cell 1 in the shell can be improved; on the second hand, it can prevent each single cell 1 from swelling, which may cause the problem of reduced cycle performance of large-capacity batteries; on the third hand, the heat generated during the charging and discharging process of each single cell 1 can be transmitted to the outside through the partition 16, reducing the risk of thermal runaway; on the fourth hand, the overall strength of the shell can be enhanced. In other embodiments, two or more single cells 1 can be fixed in each single cell 1 installation cavity. However, compared with the present embodiment, the stability of the single cell 1 is poor.

Claims

1. A process for preparing a large-capacity battery, characterized in that: The following steps are involved: Processing shell: Processing a cylinder with open ends at both ends, and processing a third through hole corresponding to each single battery pole on the top plate of the cylinder; Processing a first cover plate and a third cover plate for covering the open end of the cylinder; Installing single battery into cylinder: Arrange multiple single cells in the cylinder; make each single cell pole extend out of the corresponding third through hole on the top plate of the cylinder; seal: The outer shell area corresponding to each third through hole is fixedly sealed with the corresponding single battery shell; the first cover plate and the third cover plate are respectively sealed and connected to the two opposite open ends of the cylinder; Unpacking: By using external force or the electrolyte itself, a hole is opened in the shell of the single battery, so that the inner cavity of the electrolyte sharing chamber and the electrolyte area of ​​the inner cavity of each single battery are connected.

2. The process for preparing a large-capacity battery according to claim 1, characterized in that: The unpacking steps also include: By using external force or the electrolyte itself, a hole is opened in the single cell shell, so that the inner cavity of the gas chamber and the gas area of ​​the inner cavity of each single cell are connected.

3. The process for preparing a large-capacity battery according to claim 2, characterized in that: In the step of loading the single cells into the barrel, a plurality of single cells that have been sorted by capacity are arranged in the barrel.

4. The process for preparing a large-capacity battery according to claim 2, characterized in that: In the step of processing the shell, an aluminum extrusion process is used to integrally form a cylinder with open ends, and at the same time, a first channel and a second channel are integrally formed, which serve as an electrolyte shared chamber and a gas chamber, respectively.

5. The process for preparing a large-capacity battery according to claim 4, characterized in that: The steps of loading the single battery into the cylinder specifically include: Fix multiple single batteries into a whole and push them into the inner cavity of the cylinder from any open end of the cylinder; Using a lifting tool to support multiple single cells from the bottom, so that the bottom of each single cell is separated from the bottom of the cylinder, and the pole of each single cell extends out of the corresponding third through hole; Insert the second long supporting ribs of equal height along the length direction of the cylinder and take out the lifting tooling.

6. The process for preparing a large-capacity battery according to claim 4, characterized in that: The steps of loading the single battery into the cylinder specifically include: Push multiple single cells into the inner cavity of the cylinder from any open end of the cylinder in turn, and push each single cell into place; Each pad is inserted between the bottom of the cylinder and the bottom of the cylinder to ensure that the pole of the single battery is fully extended out of the corresponding third through hole.

7. The process for preparing a large-capacity battery according to claim 4, characterized in that: The steps of loading the single battery into the cylinder specifically include: Turn the cylinder over so that the top of the cylinder faces downward, fix multiple single batteries as a whole, and push them into the inner cavity of the cylinder from any open end of the cylinder; or push multiple single batteries into the inner cavity of the cylinder from any open end of the cylinder in sequence; Under the action of gravity, the pole of each single battery extends out of the corresponding third through hole, and the second supporting rib is inserted between the bottom of each single battery and the bottom of the cylinder; the cylinder is turned over so that the top of the cylinder faces upward.

8. The process for preparing a large-capacity battery according to claim 2, characterized in that: In the step of processing the shell, an aluminum extrusion process is used to integrally form a cylinder with open ends, and at the same time, a second channel is integrally formed to serve as a gas chamber.

9. The process for preparing a large-capacity battery according to claim 8, characterized in that: The steps of loading the single battery into the cylinder specifically include: Fix multiple single cells as a whole, and push them into the inner cavity of the cylinder from any open end of the cylinder; use a lifting tool to support multiple single cells from the bottom, so that the bottom of each single cell is separated from the bottom of the cylinder, and the pole of each single cell extends out of the corresponding third through hole; At least two first supporting ribs are inserted between the bottom of each single cell and the bottom of the cylinder along the length direction of the cylinder to form a first channel as a shared electrolyte chamber and ensure that the pole of each single cell extends out of the corresponding third through hole; Take out the lifting tool.

10. The process for preparing a large-capacity battery according to claim 8, characterized in that: The steps of loading the single battery into the cylinder specifically include: Push multiple single cells into the inner cavity of the cylinder from any open end of the cylinder in turn. After each single cell is pushed into place, insert each pad between its bottom and the bottom of the cylinder to form an electrolyte sharing chamber while ensuring that the pole of the single cell extends out of the corresponding third through hole.

11. The process for preparing a large-capacity battery according to claim 8, characterized in that: The steps of loading the single battery into the cylinder specifically include: Turn the cylinder over so that the top of the cylinder faces downward, fix multiple single batteries as a whole, and push them into the inner cavity of the cylinder from any open end of the cylinder; or push multiple single batteries into the inner cavity of the cylinder from any open end of the cylinder in sequence; Under the action of gravity, the pole of each single battery extends out of the corresponding third through hole, and at least two first supporting ribs are inserted between the bottom of each single battery and the bottom of the cylinder to form an electrolyte sharing chamber; Turn the cylinder over so the top of the cylinder is facing up.

12. The process for preparing a large-capacity battery according to any one of claims 1 to 11, characterized in that: During the unpacking process, a hole is opened in the shell of the single battery using external force or the electrolyte itself. After the inner cavity of the electrolyte shared chamber and the electrolyte area of ​​the inner cavity of each single battery are connected, the electrolyte is injected into the inner cavity of each single battery through the electrolyte shared chamber to form the entire large-capacity battery.

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