High-capacity battery and shell thereof

Abstract

The invention relates to the field of batteries, in particular to a high-capacity battery and a shell thereof. The problem that an existing large-capacity battery sharing pipeline assembly is difficult to assemble is solved. The high-capacity battery comprises a shell and a plurality of single batteries, and the single batteries are sequentially connected in parallel and arranged in an inner cavity of the shell; the shell comprises a cylinder, a first cover plate and a second cover plate; an electrolyte sharing cavity is formed in the first cover plate, and the first cover plate covers the open end of the bottom of the barrel and is in sealed connection with the open end; the electrolyte sharing chamber is communicated with the electrolyte area of the inner cavity of each single battery; the second cover plate is provided with a third through hole through which each single battery pole can extend out; the second cover plate covers the open end of the top of the cylinder and is in sealed connection with the open end. And each single battery pole extends out of the third through hole, and the shell area corresponding to the third through hole is fixedly sealed with the single battery shell. The electrolyte sharing cavity does not need to be connected in an inserted mode, the requirements for machining precision and assembling precision are low, and batch production can be achieved.

Description

Technical Field

[0001] The invention relates to the field of batteries, in particular to a large-capacity battery and a shell thereof. 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 that are interference fit with each other; 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 2, 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 large-capacity battery to overcome the problem that existing large-capacity batteries share pipeline components that are difficult to assemble.

[0013] The technical solution of the present invention is:

[0014] A large-capacity battery, which is special in that it includes a shell and a plurality of single cells, wherein the plurality of single cells are connected in parallel in sequence and arranged in the inner cavity of the shell; the inner cavity of each single cell includes an electrolyte region and a gas region;

[0015] The housing comprises a cylinder, a first cover plate and a second cover plate;

[0016] The bottom and top of the cylinder are open;

[0017] The first cover plate is provided with an electrolyte sharing chamber, the first cover plate covers the open end of the bottom of the cylinder body and is sealed and connected to the open end; the electrolyte sharing chamber is connected to the electrolyte area of ​​the inner cavity of each single battery;

[0018] The second cover plate is provided with a third through hole through which each single cell pole can extend; the second cover plate covers the open end of the top of the cylinder and is sealed with the open end; each single cell pole extends out of the third through hole and the outer shell area corresponding to the third through hole is fixedly sealed with the single cell shell.

[0019] Furthermore, a first through hole penetrating the inner cavity of each single battery is provided at the bottom of the shell;

[0020] The electrolyte sharing chamber is a first channel extending along the length direction of the first cover plate;

[0021] Alternatively, the electrolyte sharing chamber is a hollow tube extending along the length direction of the first cover plate, and a second through hole communicating with the first through hole is formed on the tube wall of the hollow tube and the first cover plate.

[0022] In order to improve the safety performance of the large-capacity battery, a gas chamber is provided on the second cover plate;

[0023] The gas chamber covers the explosion relief part on the top of each single battery. When the explosion relief part of any single battery is broken by the smoke in the inner cavity, the gas area in the inner cavity of the single battery is connected with the inner cavity of the gas chamber.

[0024] In order to further reduce the differences between the individual cells, a gas chamber is provided on the second cover plate;

[0025] A fifth through hole penetrating the inner cavity of each single cell is provided on the top of each single cell shell, and the gas area in the inner cavity of each single cell is connected with the inner cavity of the gas chamber through the fifth through hole.

[0026] The present invention also provides another large-capacity battery, which is special in that it comprises a shell and a plurality of single cells, wherein the plurality of single cells are connected in parallel in sequence and arranged in the inner cavity of the shell; the inner cavity of each single cell comprises an electrolyte region and a gas region; a first through hole penetrating the inner cavity of each single cell is provided at the bottom of the shell;

[0027] The housing comprises a cylinder, a second cover plate and a hollow box body serving as a shared chamber for electrolyte;

[0028] The bottom and top of the cylinder are open;

[0029] The hollow box body covers the open end of the bottom of the cylinder body and is sealed and connected to the open end;

[0030] A second through hole that is in communication with the first through hole is formed on the top of the hollow box body, and the inner cavity of the hollow box body is connected with the electrolyte area of ​​the inner cavity of each single battery through the first through hole and the second through hole;

[0031] The second cover plate is provided with a third through hole through which each single cell pole can extend; the second cover plate covers the open end of the top of the cylinder and is sealed with the open end; each single cell pole extends out of the third through hole and the outer shell area corresponding to the third through hole is fixedly sealed with the single cell shell.

[0032] Furthermore, the large-capacity battery also includes a heat transfer connector, which is a slender member used to connect to the positive or negative electrode of each single battery; and a clamping portion for installing a heat transfer tube is provided on the slender member along the axial direction.

[0033] Furthermore, the cylinder body also includes a plurality of partitions arranged in the inner cavity of the cylinder body, dividing the inner cavity of the cylinder body into a plurality of single cell installation cavities; at least one single cell is fixed in each single cell installation cavity.

[0034] Furthermore, the cylinder is integrally formed by an extrusion process;

[0035] Alternatively, the cylinder is formed by splicing at least two sub-cylinders; each sub-cylinder is integrally formed by an extrusion process.

[0036] The present invention also provides a housing for accommodating a plurality of single cells, which has the following features: it comprises a barrel, a first cover plate and a second cover plate;

[0037] The bottom and top of the cylinder are open;

[0038] The first cover plate is provided with an electrolyte sharing chamber, the first cover plate covers the open end of the bottom of the cylinder body and is sealed and connected to the open end; the electrolyte sharing chamber is used to communicate with the electrolyte area of ​​the inner cavity of each single battery;

[0039] The second cover plate is provided with a third through hole through which each single cell pole can extend; the second cover plate covers the open end of the top of the cylinder and is sealed and connected with the open end.

[0040] The present invention also provides another shell structure for accommodating a plurality of single cells, wherein the bottom of the shell of each single cell is provided with a first through hole penetrating the inner cavity thereof;

[0041] The special features thereof are: comprising a cylinder, a second cover plate and a hollow box;

[0042] The bottom and top of the cylinder are open;

[0043] The hollow box body covers the open end of the bottom of the cylinder body and is sealed and connected to the open end;

[0044] A second through hole is formed on the top of the hollow box, and the inner cavity of the hollow box is connected to the electrolyte area of ​​each single battery cavity through the second through hole and the first through hole;

[0045] The second cover plate is provided with a third through hole through which each single cell pole can extend; the second cover plate covers the open end of the top of the cylinder and is sealed and connected with the open end.

[0046] Furthermore, a gas chamber is provided on the second cover plate.

[0047] The beneficial effects of the present invention are:

[0048] 1. The present invention places a plurality of single cells in a shell. The shell is a split structure, including a cylinder that can accommodate a plurality of single cells, and a first cover plate and a second cover plate that seal the open end of the cylinder. The first cover plate is provided with an electrolyte sharing chamber. The electrolyte sharing chamber is connected with the electrolyte area of ​​the inner cavity of each single cell located in the shell, so that the electrolyte of each single cell is shared to ensure the consistency of each single cell. That is, the electrolyte chamber of each single cell is connected, so that the electrolyte of all single cells is in the same system, which reduces the difference between the electrolytes of each single cell, improves the consistency between each single cell to a certain extent, and thus improves the cycle life of the large-capacity battery to a certain extent.

[0049] 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.

[0050] In addition, after the first cover plate is fixed to the open end of the bottom of the cylinder, each single battery can be placed in the inner cavity of the shell from the open end of the top of the cylinder, which is easy to assemble. The cylinder can be integrally formed by extrusion process, which is easy to process and has a lower processing cost.

[0051] 2. The present invention sets a gas chamber on the second cover plate, which can directly cover the explosion venting part on the top of each single battery cell, and serve as an explosion venting pipe. When the pressure in the inner cavity of any single battery cell is too high, the inner cavity gas or thermal runaway smoke breaks through the explosion venting part on each single battery cell and enters the gas chamber, and is discharged from the gas chamber. Because each single battery cell has an explosion venting part, and the explosion venting part is located in the gas area of ​​each single battery cell, the thermal runaway smoke breaks through the explosion venting part and enters the explosion venting pipe, and the pressure holding time is short, which has higher safety.

[0052] 3. The present invention sets a gas chamber on the second cover plate, and the inner cavity of each single cell is connected with the gas chamber, so that the gas paths of each single cell are connected, and the gases of all single cells are in the same environment to achieve gas balance, thereby reducing the differences between the single cells and improving the consistency between the single cells, thereby further improving the cycle life of large-capacity batteries.

[0053] 4. The present invention divides the inner cavity of the cylinder into a plurality of single-cell battery installation cavities by adding partitions. When each single-cell battery is fixed in the corresponding single-cell battery installation cavity, the side wall is in direct contact with the partition. On the first hand, the installation stability of each single-cell battery in the shell can be improved; on the second hand, it can prevent each single-cell battery from swelling, which may lead to the problem of reduced cycle performance of large-capacity batteries; on the third hand, the heat generated during the charge and discharge process of each single-cell battery can be transmitted to the outside through the partition, reducing the risk of thermal runaway; on the fourth hand, the strength of the cylinder can also be enhanced. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 It is a schematic diagram of the structure of a large-capacity battery in the background technology;

[0055] Figure 2 This is a schematic diagram of the structure of a large-capacity battery in Example 1;

[0056] Figure 3 This is a schematic diagram of a large-capacity battery explosion in Example 1;

[0057] Figure 4This is a schematic diagram of the structure of a commercially available square shell battery in Example 1;

[0058] Figure 5 This is a schematic diagram of the housing structure in Example 1;

[0059] Figure 6 A schematic diagram of the structure of the first cover plate in Example 1;

[0060] Figure 7 is another structural schematic diagram of the first cover plate in Example 1;

[0061] Figure 8 This is another structural schematic diagram of the first cover plate in Example 1 (the electrolyte sharing chamber is tubular);

[0062] Fig. 9 This is a schematic diagram of the structure of the second cover plate in Example 1;

[0063] Fig.10 This is a schematic diagram of the structure of a large-capacity battery after a heat transfer connector is added in Example 1;

[0064] Fig.11 is a schematic structural diagram of the heat transfer connector in Example 1;

[0065] Fig.12 This is a schematic diagram of the structure of the second cover plate in Example 2;

[0066] Fig.13 This is a schematic diagram of the housing structure in Example 3;

[0067] Fig.14 This is a schematic diagram of the cylinder structure in Example 4;

[0068] The accompanying drawings in the figure are marked as follows:

[0069] 01. Sub-pipeline; 02. Intermediate connecting pipe; 03. Lower cover plate;

[0070] 1. Shell; 2. Single cell; 4. Cylinder; 5. First cover plate; 6. Second cover plate; 7. Electrolyte shared chamber; 8. Second through hole; 9. Third through hole; 10. Gas chamber; 11. Reinforcement rib; 13. Heat transfer connector; 14. Hollow box; 15. Partition; DETAILED DESCRIPTION

[0071] 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.

[0072] 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.

[0073] 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" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0074] The present invention provides a large-capacity battery, comprising a housing and a plurality of single cells arranged in parallel in the housing; the single cells described herein may be square-shell batteries or may be a plurality of commercially available soft-pack batteries connected in parallel. The inner cavity of each single cell comprises an electrolyte region and a gas region.

[0075] The following embodiments are mainly described in detail with square shell batteries as single cells. The shell structure and the specific arrangement of each single cell in the shell can be set according to specific needs. For example, when square shell batteries are selected as single cells, the shell can be a square shell, and each single cell can be arranged in sequence along the length direction of the shell; the shell can also be a cylindrical hollow shell, and each single cell can be arranged along the circumference of the shell, but compared with the square shell, the stability of the square shell battery in the cylindrical hollow shell is more difficult to ensure. In addition, the energy density of the energy storage device formed by such large-capacity batteries is average, but the large-capacity battery of this structure has better heat dissipation performance.

[0076] In view of structural stability and energy density, the present invention preferably uses a square shell as the outer shell.

[0077] The housing of the present invention can adopt the following structural forms, taking a rectangular housing as an example:

[0078] 1. The outer shell is a split structure, including a cylinder with open top and bottom, a first cover plate and a second cover plate;

[0079] This type of cylinder structure can be formed by aluminum extrusion:

[0080] Firstly, a cylinder with open top and bottom is formed by aluminum extrusion, and then a first cover plate with an electrolyte sharing chamber is processed and fixed to the open end of the bottom of the cylinder.

[0081] It should be noted that after the single cell is placed in the cylinder, the open end of the top of the cylinder is sealed by the second cover plate (each single cell pole needs to extend out of the cover plate) to ensure that the electrolyte does not contact the outside.

[0082] Second, the outer shell is a split structure, including a cylinder with open top and bottom, a second cover plate, and a hollow box that can be used as a shared chamber for electrolyte;

[0083] Similar to the first solution, this type of cylinder structure can be formed by aluminum extrusion:

[0084] First, an aluminum extrusion method is used to form a cylinder with open top and bottom, and then a hollow box is covered on the open end of the bottom of the cylinder and sealed to the open end.

[0085] After placing the single battery in the cylinder, the inner cavity of the hollow box is connected with the electrolyte area of ​​each single battery, and the open end of the top of the cylinder is sealed by the second cover (each single battery pole needs to extend out of the cover) to ensure that the electrolyte does not contact the outside.

[0086] 3. Different from the above two structures, the cylinder of this scheme is formed by welding four rectangular plates. However, due to the large number of welds, the overall strength and sealing of the cylinder are relatively poor.

[0087] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0088] Example 1

[0089] like Figure 2 and Figure 3 As shown, the large-capacity battery of this embodiment includes 9 single cells 2 connected in parallel. The number of single cells 2 in other embodiments can be adjusted according to actual needs. Figure 4 The single cell 2 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 single cell shell, and the battery cell assembly is arranged in the single cell shell.

[0090] Combination Figure 5 In this embodiment, the housing 1 adopts the first structural form mentioned above, specifically a rectangular housing, including a cylindrical body 4 with a rectangular cross section and open ends at the top and bottom, a first cover plate 5 covering the open end at the bottom of the cylindrical body 4, and a second cover plate 6 covering the open end at the top. The first cover plate 5 is provided with an electrolyte sharing chamber 7.

[0091] The first cover plate 5 can adopt different structural forms, but it is necessary to ensure the sealing of the connection part between it and the bottom open end of the cylinder 4 when it covers the bottom open end of the cylinder 4, and it is necessary to ensure that the inner cavity of the electrolyte shared chamber 7 set on the first cover plate 5 and the inner cavity of each single battery 2 are connected. In this embodiment, a flat plate that matches the shape of the bottom open end of the cylinder 4 is selected as the first cover plate 5, and the sealing between the first cover plate 5 and the bottom open end of the cylinder 4 is ensured by welding the first cover plate 5 to the edge of the bottom open end of the cylinder 4. In this embodiment, the cylinder 4 is a rectangular cylinder, so the flat plate is a rectangular flat plate, and the area can be slightly larger than the area of ​​the bottom open end of the cylinder 4, and it is fixed to the bottom open end of the cylinder 4 by fusion welding; the area can also be slightly smaller than the area of ​​the bottom open end of the cylinder 4, and it is fixed to the bottom open end of the cylinder 4 by embedding welding. By opening a first through hole that penetrates the inner cavity of each single battery 2 at the bottom of the shell, it is ensured that the inner cavity of the electrolyte shared chamber 7 and the inner cavity of each single battery 2 are connected.

[0092] In this embodiment, the structure of the first cover plate 5 and the electrolyte shared chamber 7 can be Figure 5 and Figure 6 In the structure shown, a first channel extending along the length direction of the first cover plate 5 is provided on the first cover plate 5 as the electrolyte sharing chamber 7. The first channel can also be formed directly on the first cover plate 5 by using a bending or aluminum extrusion process, and the inner surface of the first cover plate 5 is raised in a direction away from the inner surface of the first cover plate 5.

[0093] like Figure 7 As shown, Figure 5 , Figure 6 and Figure 7 The first channels in the cylinder are all protruding away from the top of the cylinder. Figure 7 The two ends of the electrolyte sharing chamber 7 are open and need to be sealed.

[0094] The structure of the first cover plate 5 and the electrolyte shared chamber 7 in this embodiment can also be Figure 8In the structure shown, the electrolyte sharing chamber 7 is a hollow tube, and the cross section can be rectangular or circular. It is an integral part with the first cover plate 5, and the integral part can also be formed by aluminum extrusion process like the cylinder 4. When a hollow tube is used as the electrolyte sharing chamber 7, it is necessary to open a second through hole 8 that penetrates the inner cavity of the electrolyte sharing chamber 7 on the tube wall and the first cover plate 5, so that the inner cavity of the electrolyte sharing chamber 7 and the inner cavity of each single battery 2 are connected. It should be noted here that there can be multiple second through holes 8, and the number is equal to that of each single battery 2, and each second through hole 8 corresponds to and penetrates the first through hole one by one; it is also possible to directly open a long strip-shaped second through hole 8 extending along the length direction of the electrolyte sharing chamber 7 in the first cover plate 5 and the electrolyte sharing chamber 7. The size of the second through hole 8 needs to ensure that when the first cover plate 5 is welded to the open end at the bottom of the cylinder 4, the second through hole 8 is connected with the first through holes of all single batteries 2.

[0095] In this embodiment, an injection port may be further provided in the electrolyte shared chamber 7. After the inner cavities of each single cell 2 and the electrolyte shared chamber are connected, electrolyte may be injected again into the inner cavities of each single cell 2 and the electrolyte shared chamber through the injection port to ensure the continuity of the electrolyte. The electrolyte may also be replaced later through the injection port.

[0096] It should be noted that when no liquid is injected, the liquid injection port needs to be sealed by a plug.

[0097] The structure of the second cover plate 6 in this embodiment is as follows Fig. 9 As shown, the second cover plate 6 is provided with a third through hole 9 through which the poles of each single battery 2 can extend; the second cover plate 6 covers the open end at the top of the cylinder 4 and is sealed and connected to the open end; preferably, the shape of the second cover plate 6 is adapted to the shape of the open end at the top of the cylinder 4. In this embodiment, the cylinder 4 is a rectangular cylinder, so the flat plate is a rectangular flat plate, and the area can be slightly larger than the area of ​​the open end at the top of the cylinder 4, and it is fixed to the open end at the top of the cylinder 4 by welding; the area can also be slightly smaller than the area of ​​the open end at the top of the cylinder 4, and it is fixed to the open end at the top of the cylinder 4 by embedding welding.

[0098] The large-capacity battery of this embodiment can be prepared by the following process:

[0099] Step 1: Process the housing 1, including the barrel 4, the first cover plate 5 with the electrolyte sharing chamber 7, and the second cover plate 6.

[0100] Step 2: seal-weld the first cover plate 5 with the electrolyte sharing chamber 7 to the open end at the bottom of the cylinder 4.

[0101] Step 3: 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 multiple single cells with sealing assemblies at the first through holes in the cylinder 4 of step 2;

[0102] If the electrolyte sharing chamber 7 is Figure 5 , Figure 6 and Figure 7 The structure shown in the figure requires that the first through hole of the sealing component corresponds to the first channel to ensure that after the sealing component is opened by external force or the electrolyte itself, the electrolyte area in the inner cavity of each single cell and the electrolyte sharing chamber 7 are connected;

[0103] If the electrolyte sharing chamber 7 is a tubular structure ( Figure 8 The structure shown in the figure) requires that the sealing component corresponds to the second through hole 8 to ensure that after the sealing component is opened by external force or the electrolyte itself, the electrolyte area in the inner cavity of each single battery and the electrolyte sharing chamber 7 are connected;

[0104] The sealing component may adopt the sealing components disclosed in Chinese patents CN218525645U and CN218525614U.

[0105] Step 4: seal and weld the second cover plate 6 to the open end of the top of the cylinder 4. After the poles of each single battery 2 extend out of the third through hole 9, the outer shell area corresponding to the third through hole 9 is fixedly sealed with the shell of the single battery 2. The edge of the third through hole 9 and the single battery shell in the area around the pole can be welded to achieve sealing;

[0106] If the sizes of the single cells 2 along the z direction are not completely equal, the shells of some single cells 2 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 9 and the single cell shell.

[0107] In order to overcome such problems, a weak portion may be provided in the peripheral area of ​​the third through hole 9. During the welding process, the size difference of each single battery in the z direction is compensated by the deformation of the weak portion, so that the poles of all single batteries 2 extend out of the third through hole 9. The weak portion in this embodiment may be an annular groove with the center of the third through hole 9 as the center point and opened along the peripheral area of ​​the third through hole 9. In other embodiments, the weak portion may also be a long strip groove opened in the peripheral area of ​​the third through hole 9. In other embodiments, if there is a similar problem, that is, the poles of all single batteries 2 cannot fully extend out of the third through hole 9 at the same time, the solution may be to add a weak portion in the peripheral area of ​​the third through hole 9.

[0108] A sealing connector may also be provided between the third through hole 9 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.

[0109] In other embodiments, the first cover plate 5, the second cover plate 6 and the open end of the cylinder 4 may also be fixed by bonding or screwing. However, compared with welding, the sealing performance or connection reliability is relatively weak.

[0110] Step 5: Use external force or the electrolyte itself to open the sealing component, so that the inner cavity of the electrolyte sharing chamber 7 and the electrolyte area of ​​each single battery cavity are connected.

[0111] After the inner cavities of each single cell 2 and the electrolyte shared chamber 7 are connected, the electrolytes in the inner cavities of each single cell 2 are connected through the electrolyte shared chamber 7. In order to prevent the interruption of the electrolyte, after the inner cavities of each single cell 2 and the electrolyte shared chamber 7 are connected, the electrolyte can be injected into the electrolyte shared chamber 7 to ensure the continuity of the electrolyte.

[0112] Then, all the single cells 2 are connected in parallel. In other embodiments, the single cells 2 may be connected in parallel between step 4 and step 5.

[0113] Specifically, you can use Fig.10 and Fig.11 The heat transfer connector 13 shown connects all the single cells 2 in parallel. The heat transfer connector 13 is a slender member used to connect to the positive or negative electrode of each single cell 2. In addition, a clamping portion for installing a heat transfer tube is provided along the axial direction of the slender member. By connecting the positive or negative electrodes of multiple single cells 2 through the heat transfer connector 13 and clamping the heat transfer tube on the heat transfer connector 13, the local temperature of the pole on each single cell 2 can be controlled, greatly reducing the occurrence of thermal runaway caused by excessive pole temperature.

[0114] 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 2 through the electrolyte sharing chamber 7, the entire large-capacity battery is formed.

[0115] Example 2

[0116] Different from the first embodiment, the present embodiment adds a gas chamber 10 on the second cover plate 6 to serve as a gas sharing chamber or an explosion relief channel.

[0117] The structure of the second cover plate 6 in this embodiment is similar to that of the first cover plate 5 in Embodiment 1, and the gas chamber 10 may be a second channel formed on the second cover plate 6, and the second channel protrudes in a direction away from the bottom of the cylinder. The second channel may also be formed integrally with the second cover plate 6 by bending or aluminum extrusion process.

[0118] The gas chamber 10 may also be a hollow tube disposed on the second cover plate 6, and may be integrally formed with the second cover plate 6 by an aluminum extrusion process. Fig.12 In other embodiments, the second cover plate 6 and the tubular gas chamber 10 may be separate structures, but the processing is more complicated.

[0119] When the gas chamber 10 is used as a gas sharing chamber, a fifth through hole penetrating the inner cavity of each single cell 2 needs to be opened on the top of the shell of each single cell 2;

[0120] When the gas chamber 10 of the second channel structure is selected, after the second cover plate 6 is fixed to the open end of the top of the cylinder 4, the second channel is directly connected to the gas area of ​​the inner cavity of each single battery through the fifth through hole.

[0121] When a hollow tube is selected as the gas chamber 10, a fourth through hole penetrating the inner cavity of the gas chamber 10 needs to be opened on the tube wall and the second cover plate 6. After the second cover plate 6 is fixed to the open end of the top of the cylinder 4, the gas chamber 10 is connected to the gas area of ​​the inner cavity of each single battery 2 through the fourth through hole and the fifth through hole. It should be noted here that there can be multiple fourth through holes, and the number is equal to that of each single battery 2, and each fourth through hole corresponds to the fifth through hole one by one and is connected; or a long strip-shaped fourth through hole extending along the length direction of the gas chamber 10 can be directly opened in the second cover plate 6 and the gas chamber 10. The size of the fourth through hole needs to ensure that when the second cover plate 6 is welded to the open end of the top of the cylinder 4, the fourth through hole is connected to the fifth through holes of all single batteries 2.

[0122] When the gas chamber 10 is used as a gas sharing chamber, an exhaust valve and an explosion-proof membrane can be set on the gas chamber 10, or only an exhaust valve can be set; 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 2 can be discharged through the gas chamber 10 and the exhaust valve; when the explosion-proof membrane is set, the exhaust valve and the explosion-proof membrane are located at both ends of the gas chamber 10, and the explosion-proof membrane is used to break through the explosion-proof membrane and discharge the hollow component when any single battery 2 has thermal runaway, 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 then seal it with a sealing assembly on the basis of the preparation process of Example 1; arrange multiple single cells with sealing assemblies at the fifth through holes in the cylinder 4; seal and weld the second cover plate 6 to the open end of the top of the cylinder 4, so that the fifth through hole with the sealing assembly corresponds to the fourth through hole, and ensure that after the sealing assembly is opened by external force or the electrolyte itself, the fifth through hole is connected with the fourth through hole; the sealing assembly can adopt the sealing assembly disclosed in Chinese patents CN218525645U and CN218525614U, and weld the edge of the third through hole 9 with the shell of the single cell 2 in the peripheral area of ​​the pole to achieve sealing. Finally, the sealing assembly is opened by external force or the electrolyte itself, and the inner cavity of the gas chamber 10 is connected with the gas area of ​​the inner cavity of each single cell.

[0125] When the gas chamber 10 is used as an explosion relief channel, the gas chamber 10 covers the explosion relief portion on the top of each single battery 2. When the explosion relief portion of any single battery 2 is broken by the internal smoke, the gas area in the internal cavity of the single battery 2 is connected to the internal cavity of the gas chamber 10.

[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 6 to the open end of the top of the cylinder 4, so that the explosion venting part of each single cell corresponds to the gas chamber 10, to ensure that after the explosion venting part is broken by the inner cavity smoke, the gas area of ​​the inner cavity of the single cell 2 is connected with the inner cavity of the gas chamber 10; weld the edge of the third through hole 9 to the shell part of the single cell 2 in the peripheral area of ​​the pole to achieve sealing.

[0128] It should be noted that the explosion relief part described in this embodiment includes an explosion relief opening or explosion-proof opening with an explosion relief membrane arranged on the top of the single battery 2, or an explosion relief opening with an explosion relief valve, etc.

[0129] Example 3

[0130] Different from the above embodiment, the housing 1 of this embodiment adopts the second structural form, and its structure is as follows: Fig.13 As shown, it includes a cylinder 4, a second cover plate 6 and a hollow box 14 serving as a shared chamber for electrolyte.

[0131] The structure and forming method of the cylinder 4 and the second cover plate 6 are the same as those of Embodiment 1 or Embodiment 2, and will not be described in detail here;

[0132] The hollow box 14 covers the open end of the bottom of the cylinder 4, and its top is sealed and connected to the open end of the bottom of the cylinder 4; it can be connected by welding or gluing, but welding has relatively higher sealing and connection reliability, so this embodiment adopts welding.

[0133] The hollow box body 14 is a hollow box body 14 with a rectangular cross-section, and a second through hole 8 that penetrates the first through hole is opened on the top of the hollow box body 14. The inner cavity of the hollow box body 14 is connected with the electrolyte area of ​​the inner cavity of each single battery 2 through the first through hole and the second through hole 8; as above, there can be multiple second through holes 8, and the number is equal to that of each single battery 2, and each second through hole 8 corresponds to and penetrates the first through hole one by one; it is also possible to directly open a long strip-shaped second through hole 8 extending along the length direction of the hollow box body 14 on the top of the hollow box body 14, and the size of the second through hole 8 needs to ensure that when the hollow box body 14 is welded to the open end at the bottom of the cylinder 4, the second through hole 8 penetrates the first through holes of all the single batteries 2.

[0134] The preparation process is basically the same as that in the above embodiment and will not be described in detail here.

[0135] Example 4

[0136] In this embodiment, a plurality of partitions 15 are provided in the inner cavity of the cylinder 4 to divide the inner cavity of the cylinder 4 into a plurality of mounting cavities for the single battery cells 2 .

[0137] Specific structure such as Fig.14 As shown, a single cell 2 is fixed in the installation cavity of each single cell 2. The side walls of each single cell 2 near the middle part are in contact with the partition 15. The two single cells 2 near the outermost part have one side wall in contact with the partition 15, and the other side wall in contact with the side wall of the cylinder 4. On the first hand, the installation stability of each single cell 2 in the shell can be improved; on the second hand, it can prevent each single cell 2 from swelling, which may lead to 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 2 can be transmitted to the outside through the partition 15, reducing the risk of thermal runaway; on the fourth hand, the strength of the cylinder 4 can also be enhanced.

[0138] Two or more single cells 2 may be fixed in each single cell 2 installation cavity.

[0139] The partition 15 and the rectangular cylinder 4 can be extruded as a whole. When the length of the rectangular cylinder 4 along the x direction is long and difficult to be completed by one extrusion, two or more sub-rectangular cylinders 4 can be extruded first, and then the sub-rectangular cylinders 4 are spliced ​​and welded to form a rectangular cylinder 4 of the required size. For the large-capacity battery in Example 1, two sub-rectangular cylinders 4 that can accommodate five single cells 2 can be extruded, and the extra single cell 2 installation cavity can be used as an electrolyte storage tank. The electrolyte storage tank is connected to the electrolyte sharing chamber and is used to add electrolyte to such large-capacity batteries.

[0140] In order to ensure the load-bearing capacity of the housing 1, the second cover plate 6 and the partition plate 15 can be welded again from above the second cover plate 6. A plurality of reinforcing ribs 11 extending in the height direction and arranged in the length direction can also be provided on the side wall of the cylinder 4. As can be seen from the figure, each reinforcing rib 11 is located in the middle of the side wall of the single cell 2 installation cavity.

[0141] In addition, when the partition 15 is provided, the second cover plate 6 excluding the gas chamber can be eliminated, and the edge of the upper cover plate of each single battery 2 is sealed and welded to the top open end of each single battery 2 installation cavity, so that the top open end of the cylinder 4 is sealed.

Claims

1. A large capacity battery, Features: It comprises a housing (1) and a plurality of single cells (2), wherein the plurality of single cells (2) are sequentially connected in parallel and arranged in the inner cavity of the housing (1); the inner cavity of each single cell (2) comprises an electrolyte region and a gas region; The housing (1) comprises a cylinder (4), a first cover plate (5) and a second cover plate (6); The bottom and top of the cylinder (4) are open; The first cover plate (5) is provided with an electrolyte sharing chamber (7), the first cover plate (5) covers the open end at the bottom of the cylinder (4) and is sealed to the open end; the electrolyte sharing chamber is in communication with the electrolyte area in the inner cavity of each single battery (2); The second cover plate (6) is provided with a third through hole (9) through which the pole of each single cell (2) can extend; the second cover plate (6) covers the open end at the top of the cylinder (4) and is sealed to the open end; the pole of each single cell (2) extends out of the third through hole (9) and the outer shell area corresponding to the third through hole (9) is fixedly sealed to the shell of the single cell (2).

2. The large-capacity battery according to claim 1, Features: The bottom of the shell of each single battery (2) is provided with a first through hole penetrating the inner cavity thereof; The electrolyte sharing chamber (7) is a first channel extending along the length direction of the first cover plate (5); Alternatively, the electrolyte sharing chamber (7) is a hollow tube extending along the length direction of the first cover plate (5), and a second through hole (8) communicating with the first through hole is provided on the tube wall of the hollow tube and the first cover plate (5).

3. The large-capacity battery according to claim 2, Features: The second cover plate (6) is provided with a gas chamber (10); The gas chamber (10) covers the explosion relief portion on the top of each single cell (2); when the explosion relief portion of any single cell (2) is breached by the internal smoke, the gas zone in the internal cavity of the single cell (2) is connected to the internal cavity of the gas chamber (10).

4. The large-capacity battery according to claim 2, Features: The second cover plate (6) is provided with a gas chamber (10); A fifth through hole penetrating the inner cavity of each single cell (2) is provided on the top of the shell of each single cell (2); the gas area in the inner cavity of each single cell (2) is connected to the inner cavity of the gas chamber (10) through the fifth through hole.

5. A large capacity battery, Features: It comprises a shell (1) and a plurality of single cells (2); the plurality of single cells (2) are sequentially connected in parallel and arranged in the inner cavity of the shell (1); the inner cavity of each single cell (2) comprises an electrolyte region and a gas region; the bottom of the shell of each single cell (2) is provided with a first through hole penetrating the inner cavity thereof; The housing (1) comprises a cylinder (4), a second cover plate (6) and a hollow box (14) serving as an electrolyte sharing chamber; The bottom and top of the cylinder (4) are open; The hollow box (14) covers the open end at the bottom of the cylinder (4) and is sealed and connected to the open end; A second through hole (8) which is in communication with the first through hole is formed on the top of the hollow box body (14); the inner cavity of the hollow box body (14) is in communication with the electrolyte area of ​​the inner cavity of each single battery (2) through the first through hole and the second through hole (8); The second cover plate (6) is provided with a third through hole (9) through which the pole of each single cell (2) can extend; the second cover plate (6) covers the open end at the top of the cylinder (4) and is sealed to the open end; the pole of each single cell (2) extends out of the third through hole (9) and the outer shell area corresponding to the third through hole (9) is fixedly sealed to the shell of the single cell (2).

6. The large capacity battery according to any one of claims 1 to 5, Features: It also comprises a heat transfer connector (13), which is a slender member used to connect to the positive electrode or negative electrode of each single battery (2); and a clamping portion for mounting a heat transfer tube is provided on the slender member along the axial direction.

7. The large capacity battery according to any one of claims 1 to 5, Features: The cylinder (4) further comprises a plurality of partitions (15) arranged in the inner cavity of the cylinder (4), dividing the inner cavity of the cylinder (4) into a plurality of single cell (2) mounting cavities; at least one single cell (2) is fixed in each single cell (2) mounting cavity.

8. The large-capacity battery according to claim 7, Features: The cylinder (4) is integrally formed by an extrusion process; Alternatively, the cylinder (4) is formed by splicing at least two sub-cylinders; each sub-cylinder is integrally formed by an extrusion process.

9. A housing for accommodating a plurality of single cells, Features: It comprises a cylinder (4), a first cover plate (5) and a second cover plate (6); The bottom and top of the cylinder (4) are open; The first cover plate (5) is provided with an electrolyte sharing chamber (7), the first cover plate (5) covers the open end at the bottom of the cylinder (4) and is sealed to the open end; the electrolyte sharing chamber is used to communicate with the electrolyte area in the inner cavity of each single battery (2); The second cover plate (6) is provided with a third through hole (9) through which the pole of each single battery (2) can extend; the second cover plate (6) covers the open end at the top of the cylinder (4) and is sealed and connected to the open end.

10. A housing for accommodating a plurality of single cells, wherein the bottom of the housing of each single cell (2) is provided with a first through hole penetrating the inner cavity thereof; Features: It comprises a cylinder (4), a second cover plate (6) and a hollow box (14); The bottom and top of the cylinder (4) are open; The hollow box (14) covers the open end at the bottom of the cylinder (4) and is sealed and connected to the open end; A second through hole (8) is provided on the top of the hollow box body (14), and the inner cavity of the hollow box body (14) is connected to the electrolyte area of ​​the inner cavity of each single battery through the second through hole (8) and the first through hole; The second cover plate (6) is provided with a third through hole (9) through which the pole of each single battery (2) can extend; the second cover plate (6) covers the open end at the top of the cylinder (4) and is sealed and connected to the open end.

11. The housing according to claim 10, Features: A gas chamber (10) is provided on the second cover plate (6).

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