Battery case, cell, large-capacity battery, and method for manufacturing the large-capacity battery

Abstract

The present application provides a battery case, a cell, a large-capacity battery, and a method for manufacturing the large-capacity battery. The battery case is provided with a sealing mechanism and an opening communicating with the inner chamber of the battery case, the sealing mechanism seals the opening, and the sealing mechanism can be opened by an external force. The battery case has a simple structure and can share electrolyte between the cells in an easy-to-operate manner, so that the cells are in a uniform electrolyte system, which ultimately solves the problem of performance differences between the cells in the large-capacity battery.

Description

[Technical field]

[0001] The present application belongs to the field of batteries, and more particularly to a battery case, a cell, a large-capacity battery, and a method for manufacturing the large-capacity battery. [Background technology]

[0002] Lithium batteries have many advantages, such as high package reliability, high system energy efficiency, simple structure, and relatively easy capacity expansion, and are therefore widely applied in various fields. In the application of conventional lithium batteries, it is often necessary to connect multiple cells in parallel to meet the requirements of large-capacity scenarios. When multiple cells are connected in parallel to form a large-capacity battery, the performance parameters of each cell, such as capacity, resistance, and voltage, are different, which affects the performance of the entire large-capacity battery. In addition, after each cell connected in parallel has been operating for a certain period of time, the consumption of electrolyte by each cell is different, which causes a large difference in the performance of each cell, which leads to poor uniformity between each cell, which further affects the performance and service life of the entire large-capacity battery. Therefore, in order to improve the performance and service life of the large-capacity battery, it is necessary to solve the consistency problem of each cell.

[0003] Having the electrolyte of multiple cells flow between each other and having multiple cells in a uniform electrolyte system solves the problem of poor consistency caused by different electrolyte consumption in each cell, but the problem of how to connect the electrolyte chambers of the multiple cells to the electrolyte chamber of the large-capacity battery remains to be solved. Summary of the Invention [Problem to be solved by the invention]

[0004] The present application provides a battery case, a cell, a large-capacity battery, and a method for manufacturing the large-capacity battery. The battery case has a simple structure and uses an easy-to-operate method to allow the cells to share an electrolyte, so that the cells are in a uniform electrolyte system, thereby solving the problem of performance differences between the cells in the large-capacity battery. [Means for solving the problem]

[0005] The present application provides a battery case, the battery case is provided with a sealing mechanism and an opening communicating with an inner chamber of the battery case, the sealing mechanism seals the opening, and the sealing mechanism can be opened by an external force.

[0006] Furthermore, the sealing mechanism includes a sealing part that is installed to seal the opening and a pulling part that is connected to the side of the sealing part that is away from the opening, and when the pulling part is pulled by an external force, the entire sealing part is detached from the opening or an opening is formed in the sealing part. In general, the opening is sealed by the sealing mechanism to prevent the inside of the unit cell from being affected, and the sealing mechanism can play a role of blocking the opening and forming an explosion dissipation membrane. When a large-capacity battery is formed by the unit cells and it is necessary to inject an electrolyte into the large-capacity battery having a shared pipeline, the openings of all the unit cells can be opened by simply pulling with an external force, and then the electrolyte is injected into the large-capacity battery through the shared pipeline, and then the electrolyte is shared by each unit cell in the large-capacity battery. In addition, since the sealing mechanism is skillfully installed at the opening of the unit cell, there is no need to add other holes or passages to the unit cell, and the structure is simple and easy to manufacture and assemble.

[0007] Furthermore, a cut is provided around the sealing part, the area surrounded by the cut is a weakened area, a traction part is provided in the weakened area, and when the traction part is pulled by an external force, the weakened area tears along the cut to form an opening. By providing the weakened area, when the traction part is pulled, the cut is easily ruptured to form an opening, making the operation easier and less difficult.

[0008] Furthermore, the shape of the weakened area is drop-shaped, circular or running track-shaped, the cross section of the cut is U-shaped or V-shaped, the weakened area is located at the center of the sealing portion, and the traction portion is eccentrically located relative to the weakened area.

[0009] Furthermore, the battery case is provided with a conduit extending along the thickness direction of the battery case, and the conduit covers the opening.

[0010] Furthermore, the battery case includes an upper cover plate, a lower cover plate and a cylinder, the upper cover plate is provided with a positive electrode post and a negative electrode post, and the opening is provided in the lower cover plate.

[0011] Furthermore, the sealing mechanism includes a fixing portion and a liquid injection portion, the fixing portion being a sheet-like structure having a through hole for fixing the sealing mechanism to the battery case, the liquid injection portion being a hollow tubular structure having an open end and a closed end, the open end being fixed to the through hole so as to communicate between the liquid injection portion and the inner chamber of the battery case, and the closed end being used to inject electrolyte into the inner chamber of the battery case after being opened by the action of an external force.

[0012] Furthermore, a protruding positioning portion is provided on the side of the through hole facing away from the liquid injection portion, and a fragile groove is provided along the circumferential direction of the liquid injection portion, and the fragile groove is provided at one end of the liquid injection portion away from the fixed portion.

[0013] The present application further provides a battery including the battery case.

[0014] Furthermore, an electrode assembly is provided within the battery case, and the battery case is provided with a conduit extending along the thickness or width direction of the battery cell and having a passage in its side wall, and the sealing mechanism is provided at an opening of the battery case corresponding to the passage.

[0015] Furthermore, several soft-pack batteries connected in parallel are provided within the battery case, and each of the cases of the several soft-pack batteries has an opening. The battery case is provided with a conduit that extends along the thickness or width direction of the cell and has a passage in its side wall, and the opening of the battery case corresponding to the passage is provided with the sealing mechanism.

[0016] Furthermore, a rectangular battery is provided within the battery case, an opening is provided in the rectangular battery case, and a conduit is provided in the battery case that extends along the thickness or width direction of the cell and has a passage in its side wall, and the sealing mechanism is provided in the opening of the battery case that corresponds to the passage, or the sealing mechanism is provided in the opening of the rectangular battery case.

[0017] The present application further provides a large-capacity battery including several of the above-mentioned cells, the several cells being connected in parallel and realizing mutual circulation of the electrolyte through a common pipe.

[0018] Furthermore, the ducts in two adjacent cells are joined by one connecting member to form a shared duct, and the inside of the connecting member is hollow and penetrates through the ducts.

[0019] The present application further provides a method for manufacturing the above-mentioned large-capacity battery, including the steps of fixing several single cells having a sealing mechanism into a group, and several single cells in the group have one shared duct; using an opening tool to open the sealing mechanisms of all the single cells using a port at any one end of the shared duct as an access port, penetrating the inner chambers of all the single cells and the shared duct; and injecting an electrolyte into the shared duct, causing the electrolyte to enter the inner chambers of each single cell, so that all the single cells are in the same electrolyte system.

[0020] Further, the opening tool includes an elongated rod having a cutting portion for cutting the sealed end of the closure mechanism, the cutting portion being a hollow circular tube having an open end with a serrated blade or the open end of the hollow circular tube being wedge shaped.

[0021] Furthermore, the battery case is mainly formed by being surrounded by a top cover assembly and a case body, the case body has an opening communicating with its inner chamber, the sealing mechanism includes a connecting tube and a sealing membrane, the connecting tube is provided in the case body and communicates with the inner chamber of the case body through the opening, the sealing membrane is provided in the opening of the case body or in the connecting tube to seal the battery case, and the sealing membrane is opened by an external force or external pressure in the connecting tube so that the electrolyte can enter the case body.

[0022] Furthermore, an opening device is provided in the connecting pipe, and the opening device can move in the connecting pipe under the action of an external pressure or a sliding device, and the opening device opens the sealing membrane.

[0023] Furthermore, the opening device has a push-up protrusion or push-up spike at one end and a circular base at the other end.

[0024] Furthermore, a wedge-shaped surface is provided on the side wall of the circular platform of the opening device, and the wedge-shaped surface is used in cooperation with the sliding device to realize rapid and accurate movement of the opening device, and a plurality of through holes are provided along the circumferential direction on the side wall at one end away from the opening of the connecting tube for circumferential injection of electrolyte, and a passage is provided inside the opening device that penetrates along the movement direction.

[0025] The present application further provides a cell including an electrode assembly and the above-mentioned battery case, wherein the electrode assembly is disposed within the battery case and immersed in an electrolyte.

[0026] The present application further provides a large-capacity battery including a liquid storage tube and a plurality of the above-mentioned single cells, the liquid storage tube being connected to any of the connecting tubes of the plurality of battery cases, and a sliding device which is a sliding rod being provided within the liquid storage tube, the sliding rod being used to push and slide the opening device into the connecting tube so that the opening device opens the sealing membrane.

[0027] Furthermore, the liquid storage pipe is provided with a liquid injection device which is a liquid injection valve, and the liquid storage pipe is further provided with an explosion dissipation device for discharging smoke generated during thermal runaway of the large-capacity battery, and the explosion dissipation device is an explosion dissipation valve.

[0028] Further, the sealing mechanism includes a sealing layer and a magnetic device, the sealing layer is provided on the case body of the battery case and seals the opening, the magnetic device is connected to the sealing layer and is located on a side of the sealing layer away from the case body, and when the magnetic device is attracted by the magnetic member, at least a portion of the sealing layer is separated from the case body, the opening is opened, and the electrolyte is injected through the opening.

[0029] Furthermore, the sealing layer and the case body are connected by adhesive, or the sealing layer is a self-adhesive tape.

[0030] Furthermore, the magnetic device is a magnetic bar connected to the sealing layer in a winding manner, or the magnetic device is a magnetic block fixed to the sealing layer in an adhesive manner.

[0031] Furthermore, the sealing mechanism is a hot melt layer, an opening communicating with the inner chamber is provided in the case body of the battery case, the hot melt layer seals the opening, and a heating device is provided in the hot melt layer. When the hot melt layer receives heat and melts, the opening is opened and the electrolyte is injected through the opening.

[0032] Furthermore, the heating device is one of a heating wire, a heating sheet or a heating belt, the heating device is connected to an external power source via a conductive wire, the hot melt layer is a hot melt tape, and the hot melt tape seals the opening.

[0033] The present application further provides a battery including an electrode assembly, an electrolyte, and the above battery case, wherein the electrode assembly and the electrolyte are both disposed within the battery case, and the electrode assembly is immersed in the electrolyte.

[0034] The present application further provides a large-capacity battery including a battery box and a plurality of the above-mentioned cells, the cells being disposed in the battery box, and an electrolyte in the battery box and an electrolyte in the battery case communicating with each other through an opening.

[0035] Furthermore, the battery box is provided with a liquid injection explosion relief port provided with an explosion relief valve. Effect of the Invention

[0036] Compared with the prior art, the technical solution of the present application has the following advantages:

[0037] 1. This application discloses a battery case, the opening of which is provided with a sealing mechanism that can be opened by external force, and by opening the opening and injecting electrolyte, mutual circulation of electrolyte in each of the cells connected by pipelines is achieved, fundamentally resolving the problem that large differences in each cell within a large-capacity battery occur due to differences in electrolyte.

[0038] 2. In the present application, a sealing mechanism with a tubular injection part and a sheet-like fixing part is provided at the opening of a battery case, and the sealing mechanism passes through a passage provided in a pipeline and extends into the pipeline to form a large-capacity battery. In this way, the closed ends of the injection parts are cut all at once or cut sequentially with a special tool while the remaining parts are recovered, thereby not only improving the efficiency of opening the openings but also ensuring that openings are formed in all of the sealing mechanisms at the same time. In addition, the sealing mechanism has a simple structure, good effectiveness, and a high single-passage rate. The sealing mechanism is made of thin metal or plastic, with a mature process, low cost, and diversified usage scenarios, and can be applied to an electrode assembly, several soft-pack batteries provided with openings, or a single battery containing a prismatic battery provided with an opening.

[0039] 3. In the present application, an opening is provided in the battery case, a connecting tube is provided at the opening, and a sealing membrane is provided in the opening of the connecting tube or the case body, and when a single cell is in operation, the sealing membrane seals the battery case, isolating the electrolyte in the battery case from the outside air. When a large-capacity battery is formed by connecting a plurality of cells in parallel, the sealing membrane is opened by the external force or pressure in the connecting tube, and the electrolyte is injected, so that the electrolyte in the plurality of cells flows between each other, and the plurality of cells are in a uniform electrolyte system, thereby greatly improving the consistency of the performance of each cell. In addition, this method also makes it easy to perform pre-filling and replenishment after capacity grading, which improves the service life of the large-capacity battery, is easy to operate, is inexpensive, and improves the production efficiency and yield of the large-capacity battery.

[0040] 4. In the present application, the sealing membrane is opened by an external acting force or external pressure within the connecting tube, which can avoid the sealing membrane being opened while in contact with air, and can effectively prevent the battery case from coming into contact with moisture in the air when it is opened. The operation method is simple and reliable, has good moisture protection, does not require the addition of other manufacturing processes, is easy to operate, improves the performance and yield of large-capacity batteries, and has a simple structure, is easy to install, and is highly versatile.

[0041] 5. In the present application, a sealing layer and a magnetic device are provided on a battery case, and when a large-capacity battery is assembled using multiple cells, the electrolyte in the battery box and the electrolyte in the cells can flow through the openings, making the performance of the entire electrolyte inside the large-capacity battery uniform and consistent, and replenishment after prefilling and capacity grading easy, thereby improving the service life of the large-capacity battery, making it easy to operate and inexpensive, and improving the production efficiency and yield of large-capacity batteries.

[0042] 6. In the present application, after the cells are connected in parallel to form a group, each cell is opened and quickly sealed to move into the cavity of the battery box, and the adhesive is peeled off by magnetic attraction, and the passage between each cell and the environment inside the battery box is released and smoothed, so that each cell is immersed in the electrolyte in the environment inside the battery box, thereby greatly improving the consistency of the energy storage performance of each cell and improving the service life of each cell. In addition, this installation can effectively prevent the battery case from coming into contact with moisture in the air when it is pierced, and the operation method is simple and reliable, has good moisture barrier properties, does not increase other manufacturing processes for the battery, and is easy to operate.

[0043] 7. The manufacturing method provided in the present application is used to manufacture a large-capacity battery, in which all the cells in the large-capacity battery are in the same electrolyte system by providing a shared pipeline, thereby reducing the adverse effects of the cask effect, ensuring that the electrolyte in each cell in the large-capacity battery is uniform, and improving the cycle life. In addition, the improved uniformity also reduces the difference in heat generation among the cells, allowing each cell to maintain approximately uniform heat generation, and reducing the probability of thermal runaway caused by excessive heat generation from individual batteries.

[0044] 8. The common duct can also be used to replenish the electrolyte in the large-capacity battery, further extending the service life of the large-capacity battery. Before forming the large-capacity battery, a sealing mechanism with a tubular injection part and a sheet-shaped fixing part is provided on the single cell, and the tubular injection part is hidden in the common duct. When forming the large-capacity battery, the opening cutter is used to cut one side close to the closed end of the injection part at once, and the tool is used to collect the remaining part, which not only improves the penetration efficiency of the opening, but also ensures that the closed ends of all the sealing mechanisms are released at the same time. The sealing mechanism has a simple structure, high effectiveness, and a high one-time penetration rate. The sealing mechanism is made of thin metal or plastic, has a mature process, low cost, and is used in a variety of situations. It can be applied to an electrode assembly, several soft-pack batteries with openings, or a single battery with a built-in single cell with openings. The present application can extend the cycle life of a large-capacity battery and improve the safety of the large-capacity battery. [Brief description of the drawings]

[0045] [Figure 1] 1 is a structural schematic diagram 1 of a sealing mechanism in Example 1 of the present application. [Diagram 2] 2 is a structural schematic diagram 2 of the sealing mechanism in the first embodiment of the present application. [Diagram 3] 1 is a structural schematic diagram 1 of a battery case in Example 1 of the present application. [Figure 4] 2 is a structural schematic diagram 2 of a battery case in Example 1 of the present application. [Diagram 5] 1 is a schematic diagram 1 of a mounting structure of a sealing mechanism and a battery case in Example 1 of the present application. [Figure 6] 2 is a schematic diagram 2 of the mounting structure of the sealing mechanism and the battery case in Example 1 of the present application. FIG. [Figure 7] FIG. 2 is a structural schematic diagram of a unit cell in Example 2 of the present application. [Figure 8] 1 is a structural schematic diagram 1 of a large-capacity battery in Example 2 of the present application. [Figure 9] 2 is a structural schematic diagram 2 of a large-capacity battery in Example 2 of the present application. [Figure 10]FIG. 1 is a structural schematic diagram 1 of a sealing mechanism in accordance with a third embodiment of the present invention. [Figure 11] FIG. 2 is a structural schematic diagram 2 of a sealing mechanism in accordance with Example 3 of the present application. [Figure 12a] FIG. 3 is a structural schematic diagram 3 of a sealing mechanism in accordance with Example 3 of the present application. [Figure 12b] FIG. 4 is a structural schematic diagram 4 of a sealing mechanism in accordance with Example 3 of the present application. [Figure 13a] 1 is a structural schematic diagram 1 of a unit cell A in Example 4 of the present application. [Figure 13b] 2 is a structural schematic diagram 2 of a unit cell A in Example 4 of the present application. [Figure 13c] 1 is a schematic diagram 1 showing a cross-sectional structure of a bottom cover plate of a unit cell A in Example 4 of the present application. [Figure 13d] 1 is a structural schematic diagram 1 of a unit cell A and a connecting member in Example 4 of the present application. [Figure 14a] 2 is a schematic diagram 2 of a cross-sectional structure of a bottom cover plate of a unit cell A in Example 4 of the present application. [Figure 14b] 2 is a structural schematic diagram 2 of a unit cell A and a sealing mechanism in Example 4 of the present application. [Figure 15] FIG. 1 is a structural schematic diagram of a unit cell B in Example 4 of the present application. [Figure 16] FIG. 1 is a structural schematic diagram of a single cell C in Example 4 of the present application. [Figure 17] FIG. 1 is a structural schematic diagram of a unit cell D in Example 4 of the present application. [Figure 18] FIG. 11 is a schematic diagram showing a flow of a method for producing a large-capacity battery in Example 5 of the present application. [Figure 19] FIG. 11 is a structural schematic diagram showing how a unit cell and a shared pipeline are joined in Example 5 of the present application. [Figure 20a] FIG. 11 is a structural schematic diagram of an unpacking cutter in accordance with a fifth embodiment of the present invention. [Figure 20b] FIG. 11 is a structural schematic diagram 1 of a cutting portion of an unpacking cutter in accordance with a fifth embodiment of the present application. [Figure 20c] FIG. 11 is a structural schematic diagram 2 of the cutting portion of the unpacking cutter in the fifth embodiment of the present application. [Figure 21]FIG. 1 is a structural schematic diagram of a large-capacity battery in Example 5 of the present application. [Figure 22] FIG. 1 is a schematic diagram 1 of a battery case in Example 6 of the present application. [Diagram 23] FIG. 2 is a schematic diagram 2 of a battery case in Example 6 of the present application. [Figure 24] FIG. 13 is a schematic diagram of a cut made in a sealing membrane in Example 6 of the present application. [Diagram 25] FIG. 1 is a schematic diagram of a large-capacity battery in Example 6 of the present application. [Figure 26] FIG. 13 is an exploded schematic view of the structure of a large-capacity battery in Example 7 of the present application. [Figure 27] FIG. 13 is a schematic diagram showing the cooperation of a connecting pipe and an opening device in Example 7 of the present application. [Figure 28] FIG. 11 is a structural schematic diagram of an opening device in Example 8 of the present application. [Figure 29] FIG. 1 is a schematic diagram of a large-capacity battery in Example 8 of the present application. [Diagram 30] FIG. 1 is a structural schematic diagram of a large-capacity battery in Example 9 of the present application. [Diagram 31] FIG. 13 is a schematic diagram of a plurality of unit cells connected in parallel in Example 9 of the present application. [Diagram 32] FIG. 13 is a schematic diagram of a rectangular opening provided in a battery case in Example 9 of the present application. [Diagram 33] FIG. 13 is a schematic diagram of a plurality of unit cells connected in parallel in Example 9 of the present application. [Diagram 34] FIG. 13 is a schematic diagram showing each battery case in Example 9 of the present application immersed in an electrolyte solution. [Diagram 35] FIG. 2 is a structural schematic diagram of a battery case in Example 10 of the present application. [Diagram 36] FIG. 23 is a structural schematic diagram of a plurality of unit cells connected in parallel in Example 10 of the present application. [Figure 37] FIG. 2 is a structural schematic diagram of a large-capacity battery in Example 10 of the present application. [Figure 38] FIG. 2 is an enlarged view of a portion of the structure of a large-capacity battery according to a tenth embodiment of the present invention. [Explanation of symbols]

[0046] 11-sealing mechanism, 111-sealing portion, 112-traction portion, 1111-notch, 1112-weakened area, 12-battery case, 121-opening, 122-pipe, 1221-connection port, 1231-upper cover plate, 1232-lower cover plate, 1233-cylinder, 124-pole, 125-connection member, 1251-connection nozzle, 1261-first battery mounting seat, 1262-second battery mounting seat, 1263-battery fixing frame, 1264-mounting member, 128-explosion dissipation assembly Bridge, 129 - sealing member, 21 - upper cover plate, 22 - lower cover plate, 221 - opening, 2211 - mounting position, 23 - cylinder, 231 - first battery assembly seat, 232 - second battery assembly seat, 233 - heat dissipation groove, 234 - reinforcing rib, 24 - pipe, 241 - connection port, 242 - passage, 25 - pole, 250 - through groove, 26 - sealing mechanism, 261 - fixing portion, 262 - liquid injection portion, 263 - positioning portion, 264 - fragile groove, 2641 - fragile segment, 27 - connection member, 271 -connecting nozzle, 28-commercially available rectangular batteries, 29-commercially available soft-pack batteries, 210-opening, 662-closing member, 663-explosion dissipation assembly, 67-connecting tube, 671-connecting nozzle, 691-elongated rod, 692-cutting part, 6921-serrated blade, 693-grip, 610-single cell, 31-case body, 32-top cover assembly, 33-connecting tube, 34-sealing membrane, 35-opening device, 36-liquid storage tube, 37-sliding rod, 38—explosion dissipation device, 311—opening, 331—through hole, 341—notch, 351—wedge-shaped surface, 352—positioning boss, 41—battery case, 42—single cell, 43—battery box, 44—magnetic member, 411—case body, 412—sealing layer, 413—magnetic device, 414—opening, 51—case body, 52—hot melt layer, 53—opening, 54—heating device, 55—electrode assembly, 56—battery box, 57—pouring explosion dissipation port, 58—conductive wire. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0047] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be described in more detail below with reference to the drawings and examples. It should be understood that the specific examples described herein are only for the purpose of interpreting the present application, and are not intended to limit the present application.

[0048] Example 1 As shown in Figures 1 to 5, this embodiment provides a battery case. The battery case is provided with an opening 121 communicating with the inner chamber, and a duct 122 extending along the thickness direction of the battery case, the duct 122 covers the opening 121 and penetrates the opening 121 and a sealing mechanism 11 is provided at the opening 121, which seals the opening 121 in the battery case. The sealing mechanism 11 is provided at the opening 121 of the battery case and is removable when the pulling part 112 is pulled by an external force, and the opening 121 is opened to inject the electrolyte, thereby fundamentally solving the problem of large discrepancies in large-capacity batteries due to differences in the amount or composition of the electrolyte.

[0049] In some embodiments, the battery case includes a top cover plate 1231, a bottom cover plate 1232, and a cylinder 1233, the top cover plate 1231 is provided with poles 124, the poles 124 including positive and negative poles, and the opening 121 is provided in the bottom cover plate 1232. The opening 121 is provided in the bottom cover plate 1232, which is advantageous for assembling a large-capacity battery, thereby reducing the volume of the large-capacity battery, and is also advantageous for reducing the amount of electrolyte used when adding electrolyte, which is advantageous for sharing, and improves the compatibility of the battery. The bottom cover plate 1232 and the duct 122 are integrally formed aluminum extrusion members, and the bottom cover plate 1232 and the duct 122 are processed in the form of extrusion, which is simple in process, low cost, and effective in use.

[0050] As shown in FIG. 1, the sealing mechanism 11 in this embodiment includes a sealing part 111 and a pulling part 112, the sealing part 111 is sealed and installed corresponding to the opening 121, the pulling part 112 is connected to the side of the sealing part 111 away from the opening 121, and when the pulling part 112 is pulled by an external force, the whole sealing part 111 is detached from the opening 121 or an opening is formed in the sealing part 111. By pulling the sealing mechanism 11 at the opening 121 by an external force to open the opening 121, the electrolyte of each unit cell connected by the pipe 122 in the large-capacity battery is shared, and the use of this structure solves the problem that the performance and life of the large-capacity battery are affected by the electrolyte of each unit cell being different. In addition, since the sealing mechanism 11 is skillfully installed at the opening 121 of the unit cell, there is no need to add other holes or passages to the unit cell, and the structure is not only simple but also easy to manufacture and assemble.

[0051] As shown in FIG. 2, in some embodiments, the sealing portion 111 is provided with a circumferential cut 1111, the area surrounded by the cut 1111 is a weakened area 1112, and a traction portion 112 is provided in the weakened area 1112. When the traction portion 112 is pulled by an external force, the weakened area 1112 is torn along the cut 1111 to form an opening. By providing the weakened area 1112, when the traction portion 112 is pulled, the cut 1111 is easily broken to form an opening, which makes the operation easier and reduces the difficulty of forming an opening. The cut 1111 is based on the ability to form an opening, and the traction portion 112 is provided within the cut 1111 and is provided eccentrically, close to the cut 1111 line.

[0052] In some embodiments, as shown in FIG. 5, the sealing part 111 is provided in the opening 121 by adhesion or welding, or as shown in FIG. 6, the sealing part 111 is covered by the opening 121 by adhesion or welding. The sealing part 111 can be easily and simply fixed to the opening 121 by welding or adhesion, which is low cost, efficient and effective. The sealing part 111 is a PP plastic sheet, a PE plastic sheet or an aluminum sheet. The sealing part 111 made of a PP plastic sheet, a PE plastic sheet or an aluminum sheet is low cost, does not react with the electrolyte, is not dissolved in the electrolyte, and has a high sealing effect when fixed by welding or adhesion.

[0053] In some embodiments, the shape of the weakened area 1112 is drop-shaped, circular or running track-shaped, and the cross section of the incision 1111 is U-shaped or V-shaped. The U-shaped or V-shaped incision 1111 is easy to process and has a good use effect. The drop-shaped weakened area 1112 is easy to peel off, and the circular and running track-shaped weakened areas 1112 are easy to process. In order to ensure that all the cells can be opened smoothly, the general preferred method is to use the drop-shaped shape as the weakened area 1112. The weak area 1112 is located in the center of the body of the sealing part 111, and the weak area 1112 is located at the center position of the body of the sealing part 111, which is advantageous for processing operations, and the area occupied by the weak area 1112 can be made as large as possible, which is advantageous for improving the injection speed and efficiency.

[0054] In some embodiments, the tow portion 112 is eccentrically disposed in the weakened area 1112. Compared to being disposed centrally, the eccentrically disposed tow portion 112 is advantageous in improving peeling efficiency and facilitating operation.

[0055] Example 2 As shown in FIG. 7, this embodiment provides a single cell including the battery case described in the embodiment 1. The battery case 12 houses an electrode assembly or several soft-pack batteries with openings, and the case of the soft-pack battery is provided with an opening for injecting an electrolyte. The battery case 12 includes an upper cover plate 1231, a lower cover plate 1232, a cylinder 1233, and a duct 122. The upper cover plate 1231 is provided with a positive electrode pole and a negative electrode pole. The lower cover plate 1232 is provided with an opening 121, and further provided with a duct 122 that covers the opening 121 and extends along the thickness direction of the battery case 12. The opening 121 is circular and may be an elongated through hole. Providing the opening 121 in the lower cover plate is advantageous for assembling a large-capacity battery, and is also advantageous for reducing the volume of the large-capacity battery and the amount of electrolyte used when adding the electrolyte. The lower cover plate and the duct are integrally molded aluminum extrusion members. The bottom cover plate and the duct are processed by extrusion, which is simple in process, low in cost and good in use.

[0056] As shown in Figures 7, 8 and 9, this embodiment further provides a large-capacity battery including a plurality of the above-mentioned single cells. The pipelines 122 between the single cells are connected to each other by a connection member 125. The outer dimensions of the connection member 125 correspond to the outer dimensions of the pipelines 122, which helps to improve the stability of the connection between the pipelines 122. The connection member 125 includes two connection nozzles 1251, and connection ports 1221 are provided at both ends of the pipeline 122, and the connection nozzles 1251 are fitted into the connection ports 1221 for a hermetic connection, or the connection member 125 includes two connection ports, and connection nozzles are provided at both ends of the pipeline 122, and the connection nozzles are fitted into the connection ports for a hermetic connection. The shape of the connection nozzle 1251 is preferably a micro-cone shape that is easy to insert into the connection port 1221, and it is preferable that the connection nozzle 1251 and the connection port 1221 are tightly fitted, the connection nozzle 1251 and the connection port 1221 are crimped, or the connection nozzle 1251 and the connection port 1221 are screwed or glued. The opening 121 is provided with a sealing mechanism 11, which is used to protect the electrode assembly or the soft-pack battery with the opening in the case from contacting air before the formation and capacity grading of the battery, or to function as an explosion dissipation membrane. When forming a large-capacity battery, the sealing mechanism 11 is opened after the pulling part 112 is pulled by an external force, so that the opening 121 is formed in the sealing part 111, or at least a part of the opening 121 is exposed, so that the electrolyte enters the battery case 12, and the electrolyte of the multiple single cells flows between each other.

[0057] 8 and 9, when installing a large-capacity battery, each cell is fixed to a battery fixing frame 1263 by a first battery mounting seat 1261 and a second battery mounting seat 1262, and connected by a mounting member 1264, which facilitates transportation and fixing. After connection, the pipe 122 is provided with an explosion dissipation assembly 128 at one end and a blocking member 129 at the other end, and the explosion dissipation assembly 128 is used as an explosion dissipation port for the large-capacity battery, and the explosion dissipation assembly 128 is used to inject electrolyte after removal, and performs electrolyte injection, electrolyte replacement, or electrolyte exchange for the large-capacity battery.

[0058] In this embodiment, a common electrolyte passage for the large-capacity battery is formed between the cells by connecting the ducts 122 in the battery case 12, and one end of the common electrolyte passage is provided with a liquid injection port. After the common electrolyte passage is formed by connecting the ducts 122, the electrolyte injected from the liquid injection port enters the battery case 12 through the opening 121, so that all the cells in the large-capacity battery are in a uniform electrolyte environment, and the uniformity of each cell in the large-capacity battery can be effectively improved. The liquid injection port can also be used to replenish and replace the liquid in the large-capacity battery. After the large-capacity battery has been used for a certain number of years, the electrolyte will be lost. At this time, the electrolyte can be extracted and replaced with a new electrolyte, or the new electrolyte can be directly added, both of which are useful for extending the service life of the large-capacity battery. When used in a conventional situation, an explosion dissipation mechanism is removably provided at the injection port, and when thermal runaway occurs in any of the batteries in the large-capacity battery, the smoke generated by the thermal runaway passes through the opening 121, is collected in the electrolyte shared passage, and is then discharged to a location designated by the explosion dissipation mechanism for effective treatment, for example, by cooling and adsorbing the smoke caused by thermal runaway before discharging it, or by igniting it.

[0059] Example 3 This embodiment provides a battery case having an opening, and the sealing mechanism seals the opening of the battery case. As shown in Figs. 10, 11, 12a and 12b, the sealing mechanism 26 includes a fixing part 261 and a liquid injection part 262, and the fixing part 261 is a sheet-like structure having a through hole for fixing the sealing mechanism 26 to the battery case. In the sealing mechanism 26 of the first embodiment shown in Figs. 10 and 11, the through hole is circular, and the fixing part 261 is also a circular sheet-like structure that extends slightly along the circumferential direction of the through hole and can be fixed to the battery case corresponding to the opening. In the sealing mechanism 26 of the second embodiment shown in Figs. 12a and 12b, the through hole is a rod-shaped hole, the fixing part 261 is a rectangular sheet-like structure, and the area of ​​the fixing part 261 is large, which is suitable for a single battery having an opening provided in the lower cover plate 22. The liquid injection part 262 of the two types of sealing mechanism 26 is a hollow tubular structure with an open end and a closed end, the open end is fixed to a through hole so that the liquid injection part 262 communicates with the inner chamber of the battery case, and the closed end is used to inject the electrolyte into the inner chamber of the battery case after being opened by the action of an external force. The method of opening the closed end may be a method of cutting the closed end from the side of the liquid injection part 262 with a sharp tool to form a passage with both ends open in the tubular liquid injection part 262.

[0060] As shown in FIG. 11 , in some embodiments, in order to facilitate positioning and attachment, a protruding positioning portion 263 is provided along the circumferential direction of the through hole on the side facing away from the liquid injection portion 262 of the through hole, and is attached to the opening of, for example, a commercially available square battery case, so that the positioning portion 263 can be inserted into the opening of the commercially available square battery to accurately attach the sealing mechanism 26.

[0061] As shown in Figs. 10, 11, 12a and 12b, in some embodiments, the infusion portion 262 is provided with a weakened groove 264 along its circumferential direction. The purpose of providing the weakened groove 264 is to allow a tool to easily cut the infusion portion 262 from the weakened groove 264, thereby improving the success rate and efficiency of cutting. Preferably, the weakened groove 264 is provided at one end of the infusion portion 262 away from the fixed portion 261, so that a cutting tool having an elongated and small tube diameter can easily cut from the bottom end of the infusion portion 262. In some embodiments, a segment near the closed end of the infusion portion 262 can also be designed as a weakened segment 2641, and the weakened segment 2641 is tapered or has a smaller thickness than other parts of the infusion portion 262 to facilitate cutting.

[0062] Example 4 This embodiment provides different types of cells, which include the battery case provided in embodiment 3, and when the sealing mechanism 26 is fixed to the battery case, it varies according to the type of the cells, and this embodiment provides a detailed description of cells A to D.

[0063] The cell A as shown in Figures 13a, 13b, and 13c includes a battery case including an upper cover plate 21, a lower cover plate 22, and a cylinder 23, and an electrode assembly is placed in the battery case and filled with an electrolyte. A pair of poles 25 is provided on the upper cover plate 21, and the positive and negative electrodes of the electrode assembly are electrically connected to the positive and negative poles, respectively. An opening 221 is provided on the lower cover plate 22, and a duct 24 is provided to cover the opening 221 and extend along the thickness direction of the cell, and a passage 242 is provided on the side wall of the duct 24. As shown in Figure 13a, the opening 221 and the passage 242 are each a circular hole, or may be a rod-shaped hole as shown in Figure 14a. In this embodiment, the pipeline 24 is an aluminum extrusion member designed and molded integrally with the bottom cover plate 22, at which time the opening 221 and the passage 242 are merged into one passage, the sealing mechanism 26 in Figure 10 is installed within the passage 242, the sealing mechanism 26 is a plastic member, the fixing portion 261 is adhered to the outwardly extending edge of the opening 221 of the bottom cover plate 22 (if an attachment position 2211 is provided, the fixing portion 261 is adhered to the attachment position 2211), the injection portion 262 extends into the passage 242 and also extends into the pipeline 24, and the opening 221 of the bottom cover plate 22 is sealed. The cylindrical body 23 is an aluminum extrusion member, and the bottom cover plate 22 is fixed to one end of the cylindrical body 23 by laser welding. After the electrode assembly is inserted into the cylindrical body 23, the top cover plate 21 is welded to the other end of the cylindrical body 23. Furthermore, electrolyte is poured into the battery through the electrolyte filling port in the top cover plate 21, the electrolyte filling port is sealed, and the battery is formed by chemical conversion to form a single cell A.

[0064] In this embodiment, the opening 221 and the passage 242 are circular holes, and the fixing part 261 and the liquid injection part 262 of the sealing mechanism 26 may be provided in a circular, elliptical or running track ring shape, or even in a triangular, rectangular or polygonal shape according to the shape changes of the opening 221 and the passage 242, and as shown in Fig. 14b, the dimensions of the fixing part 261 are designed to be approximately the same as those of the bottom cover plate 22 to facilitate sealing and fixing in the later stage. The sealing mechanism 26 in this embodiment may also be manufactured from aluminum, which is the same material as the bottom cover plate 22, and in this case, the sealing mechanism 26 is fixed by welding.

[0065] The cell B shown in Fig. 15 is manufactured from a commercially available rectangular battery 28 (hereinafter referred to as a rectangular battery). For example, a 280 Ah battery commonly seen on the market has a case made of aluminum, a sealed inner chamber, an electrolyte is contained in the inner chamber, and at least one electrode assembly is provided in the inner chamber. Preferably, in an environment with a dew point standard of -25°C to -40°C, a temperature of 23°C ± 2°C, and a cleanliness level of 100,000, an opening is made in the case of the rectangular battery, and the opening is sealed with the sealing mechanism 26 of Fig. 11. The sealing mechanism 26 is made of aluminum, and the positioning part 63 is inserted into the opening, and then the fixing part 261 is welded to the case at the opening to seal the opening, and the inner chamber of the electrolyte injection part 262 is connected to the opening, and is ready for use.

[0066] The cell B further includes a battery case, the battery case having an opening in a bottom cover plate, a duct 24 covering the opening and extending along the thickness direction of the cell, and a passage in a side wall of the duct 24. As shown in FIG. 13a, the opening and the passage are circular holes, and as shown in FIG. 14a, they may be rod-shaped holes. In this embodiment, the duct 24 is an aluminum extrusion member that is designed and molded integrally with the bottom cover plate 22. At this time, the opening and the passage are merged into one passage. The cylindrical body 23 is an aluminum extrusion member, the bottom cover plate is fixed to one end of the cylindrical body 23 by laser welding, and the positive and negative poles of the rectangular battery are electrically connected to the positive and negative poles of the top cover plate, respectively. The rectangular battery with the top cover plate welded to it is placed in the cylindrical body 23, and the electrolyte injection portion 262 of the sealing mechanism 26 passes through the passage and extends into the duct 24. Then, the top cover plate with the rectangular battery welded to it is welded to the other end of the cylindrical body 23 to form the cell B.

[0067] In this embodiment, a top cover plate is not required for the unit cell B, as long as the positive and negative electrode posts of the prismatic battery can be pulled out and the upper gap can be sealed after the prismatic battery and the cylinder body 23 are attached. In this embodiment, after the prismatic battery is opened, it can also be sealed with the sealing mechanism 26 of Figures 10 and 12a. The sealing mechanism 26 in this embodiment may be made of plastic that is insoluble in the electrolyte, and in this case, the sealing mechanism 26 is bonded to the case opening of the prismatic battery.

[0068] A single cell C as shown in FIG. 16 is manufactured from a commercially available rectangular battery 28 (hereinafter referred to as a rectangular battery). For example, a 280 Ah battery commonly seen on the market has a case that is usually made of aluminum, has a sealed inner chamber, contains an electrolyte, and is provided with at least one set of electrode assemblies.

[0069] The cell C includes a battery case, as shown in FIG. 13a, the battery case has an opening 121 in the bottom cover plate, a duct 24 covering the opening and extending along the thickness direction of the cell, and a passage 242 on the side wall of the duct 24, the opening 221 and the passage 242 are circular holes, or may be rod-shaped holes as shown in FIG. 14a. In this embodiment, the passage 24 is an aluminum extrusion member that is designed and molded integrally with the bottom cover plate 22, at which the opening 221 and the passage 242 are merged into one passage, and the sealing mechanism 26 shown in FIG. 10 is installed in the passage 242, the sealing mechanism 26 is a plastic member, and the fixing part 261 is a corresponding part of the opening 221 of the bottom cover plate 22. The upper cover plate 21 is fixed to one end of the cylindrical body 23 by laser welding, and the positive and negative poles of the rectangular battery are electrically connected to the positive and negative poles of the upper cover plate 21, respectively. Preferably, in an environment with a dew point standard of between -25°C and -40°C, a temperature of 23°C±2°C, and a cleanliness level of 100,000, an opening 210 is formed in the bottom of the case of the rectangular battery, and then the rectangular battery is placed into the cylindrical body 23, and the upper cover plate 21 and the other end of the cylindrical body 23 are welded and fixed to form a single cell C.

[0070] In this embodiment, it is not necessary to use the top cover plate 21 for the cell C, as long as the positive and negative electrode posts of the rectangular battery can be pulled out and the upper gap can be sealed after the rectangular battery and the cylindrical body 23 are attached. In this embodiment, the opening 221 of the bottom cover can also be sealed with the sealing mechanism 26 of Fig. 12a. The sealing mechanism 26 in this embodiment may be made of aluminum, the same material as the bottom cover plate 22, and in this case, the sealing mechanism 26 is fixed by welding.

[0071] The single cell D shown in FIG. 17 is manufactured from a commercially available soft-pack battery 29 (hereinafter referred to as a soft-pack battery). The soft-pack battery case is usually made of an aluminum plastic membrane and has a sealed inner chamber, in which an electrolyte is contained, and in which at least one electrode assembly is provided.

[0072] As shown in FIG. 13a, the cell D includes a battery case, in which an opening 221 is provided in a bottom cover plate 22, a duct 24 is provided to cover the opening 221 and extend along the thickness direction of the cell, and a passage 242 is provided in a side wall of the duct 24, and the opening 221 and the passage 242 are circular holes, or may be rod-shaped holes as shown in FIG. 14a. In this embodiment, the passage 24 is an aluminum extrusion member that is designed and molded integrally with the bottom cover plate 22, and the opening 221 and the passage 242 are formed integrally with the bottom cover plate 22. are merged into one passage, and sealing mechanism 26 shown in Figure 10 is attached within the passage, sealing mechanism 26 is a plastic member, fixing portion 261 is adhered to the corresponding edge of opening 221 of bottom cover plate 22 (when mounting position 2211 is provided, fixing portion 261 is adhered to mounting position 2211), injection portion 262 extends into passage 242 and also extends into pipeline 24, opening 221 of bottom cover plate 22 is sealed, cylinder 23 is an aluminum extrusion member, and bottom cover plate 22 is fixed to one end of cylinder 23 by laser welding. In this embodiment, seven soft-pack batteries are used, and the positive and negative tabs of the seven soft-pack batteries are welded in parallel to the positive and negative poles 25 of the top cover plate 21. After opening the case of the soft-pack battery, preferably in an environment with a dew point standard of between -25°C and -40°C, a temperature of 23°C ± 2°C, and a cleanliness level of 100,000, the seven soft-pack batteries with the welded top cover plate 21 are placed into a cylindrical body 23, and the top cover plate 21 is welded and fixed to the other end of the cylindrical body 23, forming a single cell D.

[0073] In this embodiment, it is not necessary to use top cover plate 21 for cell D, as long as the positive and negative tabs of the soft-pack battery can be pulled out and the upper gaps after the soft-pack battery and cylindrical body 23 are attached and the upper gaps between the soft-pack batteries can be sealed. The opening 221 in the bottom cover in this embodiment can also be sealed with sealing mechanism 26 in Fig. 12a. The sealing mechanism 26 in this embodiment may be made of aluminum, the same material as the bottom cover plate 22, and in this case, the sealing mechanism 26 is fixed by welding.

[0074] The function of the conduits 24 in the cells A to D will be described in detail below.

[0075] As shown in Figures 13a, 13b, 13c and 13d, when some cells provided with sealing mechanism 26 are used to form a large-capacity battery, a through passage is formed by connecting duct 24 to serve as an electrolyte sharing passage of the large-capacity battery. The electrolyte sharing passage has a plug at one end and a port at the other end for detachably connecting another assembly. An injection assembly or an explosion relief valve is installed. Before installing the injection assembly, a special tool is used to penetrate deep into the electrolyte sharing passage to seal it. The sealing mechanism 26 cuts the exposed electrolyte injection parts 262 one by one to connect the inner chambers of all the cells to the electrolyte common passage, and uses a special tool to collect the remaining parts. After the electrolyte injection assembly is installed, the electrolyte is injected into the electrolyte common passage by the electrolyte injection assembly, and the electrolyte passes through the passage 242 and the opening 221 one by one into the battery case, so that all the cells in the large-capacity battery are in a uniform electrolyte environment, which effectively improves the uniformity of the electrolyte in the large-capacity battery. After the electrolyte injection is completed, the explosion relief valve is replaced. The electrolyte common passage can also be used to replenish and replace the electrolyte in the large-capacity battery. After the large-capacity battery has been used for a certain number of years, there will be a loss of electrolyte, so the explosion relief valve can be replaced, the electrolyte injection assembly can be installed, and the electrolyte can be extracted and replaced with new electrolyte, or new electrolyte can be directly added. Both of these two methods are useful for extending the service life of the large-capacity battery. With the above structure, if thermal runaway occurs in any of the cells, the smoke caused by the thermal runaway in the cells passes through the opening 221 and the passage in sequence, is discharged into the electrolyte shared passage formed by the pipe 24, and is then discharged after passing through the explosion relief valve.

[0076] As shown in Fig. 13d, the pipelines 24 are connected and fixed by a connecting member 27 to form a common electrolyte passage. The outer dimensions of the connecting member 27 correspond to the outer dimensions of the pipelines 24, which helps to improve the stability of the connection between the pipelines 24. Preferably, the connecting member 27 includes two connecting nozzles 271, and the pipelines 24 are provided with connecting ports 241 at both ends thereof, and the connecting nozzles 271 are fitted into the connecting ports 241 for a hermetic connection; or the connecting member 27 includes two connecting ports 241, and the pipelines are provided with connecting nozzles 271 at both ends thereof, and the connecting nozzles 271 are fitted into the connecting ports 241 for a hermetic connection. The shape of the connection nozzle 271 is preferably a micro-cone shape that is easy to insert into the connection port 241, and it is preferable that the connection nozzle 271 and the connection port 241 are tightly fitted together or the connection nozzle 271 and the connection port 241 are crimped together. When crimping, an adhesive such as an epoxy adhesive can be added to the crimped surface, which will improve the sealing and fixing effect, or the connection nozzle 271 and the connection port 241 are screwed together.

[0077] 13a, the pole 25 in this embodiment is provided with a through groove 250 for attaching a heat transfer tube, and the opening of the through groove 250 is located at the end face of the pole 25. The end face is further provided with an electrical connection area, which is simultaneously connected to the electrical connection areas of multiple poles 25 of the same gender via a single elongated L-shaped plate-like connecting member 27, thereby realizing parallel connection of multiple unit cells.

[0078] As shown in Figs. 13a and 13b, the bottom cover plate 22 is further provided with a first battery assembly seat 231 along its width direction, and the side wall of the cylinder 23 is further provided with a second battery assembly seat 232 along its height direction. When forming a battery pack with the single cells, the single cells are assembled into a large-capacity battery by attaching an assembly rod to the first battery assembly seat 231 and the second battery assembly seat 232, and the assembly seat is provided with a screw hole for fixing. The outer surface of the cylinder 23 is provided with several heat dissipation grooves 233 extending along its height direction, which facilitates heat dissipation of the single cells. The cylinder 23 is further provided with several reinforcing ribs 234 extending along its height direction, which improves the crush strength of the cylinder 23. In some embodiments, the duct 24 may be provided on the side wall of the battery cylinder 23.

[0079] Example 5 As shown in FIG. 18, this embodiment provides a method for manufacturing a large-capacity battery, which includes steps S1 to S3.

[0080] In S1, several cells having a sealing mechanism are arranged and fixed in a group, and a common duct is formed for the several cells in the group;

[0081] In this step, the sealing mechanism of the single cell is used to seal the opening in the single cell, and accordingly, the shared conduit has several through holes spaced apart on the side wall of the conduit, each through hole corresponding to the sealing mechanism of one single cell; with such a design, the electrolyte sharing conditions required for the subsequent step S2 can be provided.

[0082] In S2, a port at one end of the shared duct is used as an access port, and an unpacking tool is used to open the sealing mechanisms of all the cells, penetrating the inner chambers of all the cells and the shared duct.

[0083] In S3, electrolyte is injected into the common conduit, allowing the electrolyte to enter the inner chamber of each cell, so that all cells in the large-capacity battery are in the same electrolyte system.

[0084] In the above step S1, the shared pipeline can be configured in the following two types.

[0085] First, after the cells are arranged in an array, a single integrally molded pipe may be welded to each cell, and after welding, the sealing mechanisms of each cell may be ensured to be located within a shared pipe.

[0086] Second, the common duct may be formed by joining the ducts provided in the unit cells during the arrangement of the unit cells. Considering the processing cost, the convenience of assembly, and the sealing property, it is preferable to adopt a joining type common duct.

[0087] Based on the above-mentioned joint type common duct, the single cell can have the following three structural forms.

[0088] First, the schematic structure of the single cell is as follows: a commercially available finished rectangular case battery is mounted in an aluminum rectangular housing, a common duct is provided in the rectangular housing, and a sealing mechanism is provided at a position corresponding to the duct. The sealing mechanism may be provided in the rectangular housing or in the case of the commercially available finished rectangular case battery.

[0089] Second, the outline of the structure of the single cell is as follows: Several commercially available soft-pack batteries are connected in parallel and then mounted in an aluminum rectangular housing. The common duct is provided in the rectangular housing, and a sealing mechanism is provided at a position corresponding to the duct in the rectangular housing.

[0090] The outline of the structure of the cell is as follows: the electrode assembly is disposed in a rectangular housing, and the rectangular housing contains an electrolyte. The common duct is provided in the rectangular housing, and a sealing mechanism is provided at a position corresponding to the duct of the rectangular housing.

[0091] Specifically, the structure of the above-mentioned unit cell can be referred to the unit cell in Example 2 and the unit cells A, B, C and D in Example 4.

[0092] Usually, one large-capacity battery is formed by assembling only one type of cells 610, and the cells can be mixed and assembled as required only when the consistency of each item meets the requirements.

[0093] As shown in FIG. 19, when a plurality of cells 610 are fixed into a group, the ducts in each cell 610 are joined to form a shared duct. The ducts in two adjacent cells 610 can be joined by one connecting pipe 67, specifically, the connecting pipe 67 has protruding connection nozzles 671 at both ends, and the ducts have corresponding connection ports at both ends, and the connection nozzles 671 of the connecting pipe 67 are fitted into the connection ports of the two adjacent ducts to realize the joining of the shared duct, and this design is helpful in simplifying the processing process. Such a segmented shared duct is not only advantageous in processing, but also eliminates the sealing and installation process between the duct and the cell 610 case compared with one complete shared duct, and can avoid liquid leakage caused by poor sealing between the two, and the processing and installation costs are relatively low.

[0094] In some embodiments, the connecting pipe 67 can be omitted, and when the lines are joined to form a common line, the lines provided in the housing can be joined to each other in the form of a male-female joint to form a common line, i.e., one end of the line is provided with a connecting nozzle 671 protruding from the line, and the other end of the line is provided with a corresponding recessed connecting port, and the connecting nozzle 671 of one line can be fitted into the connecting port of another line, and such a design can reduce the number of parts for joining the common line. However, such a design does not allow the production of parts by an extrusion process, and increases the processing cost compared to the solution using the connecting pipe 67.

[0095] After the shared duct is formed, the key point in step S2 is how to open the sealing mechanism to communicate all the internal chambers of each of the cells 610 having the shared duct. There are a number of different forms and methods for this step, and the order of steps can be changed. For example,

[0096] When using a single cell 610 with a sealing mechanism having a fixing part and a liquid injection part, the sealing mechanism can be opened with an unpacking tool, and the specific structure of the unpacking tool is as follows.

[0097] 20a, 20b, and 20c are structural schematic diagrams of an unpacking cutter used to cut the sealing mechanism in the above manufacturing method. The unpacking cutter includes an elongated rod 691, and one end of the elongated rod 691 is provided with a cutting part 692 for cutting the sealing mechanism. The other end of the elongated rod 691 is provided with an operating grip 693 for facilitating the operation of the elongated rod 691. The cutting part 692 includes a hollow tube for collecting the remaining part of the sealing mechanism, and the end of the hollow tube is provided with a serrated blade 6921. In some embodiments, the cutting part 692 is a hollow tube with a wedge-shaped end. Specifically, when used, the unpacking cutter extends from the operation port of the shared duct, and in the process of extending, the cutting part 692 of the unpacking cutter sequentially cuts the closed end of the liquid injection part that has extended into the shared duct of the sealing mechanism, and then uses the hollow tube of the cutting part 692 to collect the remaining part of the cut closed end, preventing it from entering the inner chamber of the single cell 610 and affecting the battery performance. The dimensions of the cutting part 692 of the unpacking cutter are designed to be larger than the diameter of the elongated rod 691, and most preferably, the outer diameter of the cutting part 692 is slightly smaller than the inner diameter of the shared pipe to facilitate cutting. The length of the cutting part 692 does not need to be very long, as designing it to be too long would increase the manufacturing cost of the unpacking cutter, so it is sufficient to ensure that the hollow pipe can accommodate the entire cut closed end remnant. In addition, since the cutting part 692 is intended to cut the sealing mechanism, the hardness of the material is higher than that of the elongated rod 691.

[0098] FIG. 21 is a schematic diagram of the structure of a large-capacity battery manufactured based on the manufacturing method provided in this embodiment from different angles. As described above, before forming the large-capacity battery, the openings of each of the cells 610 are sealed by a sealing mechanism. When forming the large-capacity battery, an opening is formed in the sealing mechanism with an unpacking tool, and then the inner chambers of all the cells 610 are connected to a shared pipeline, and electrolyte is injected into the inner chambers of all the cells 610 through the shared pipeline, so that all the cells 610 in the large-capacity battery are in the same electrolyte system, thereby improving the uniformity of each cell 610 in the large-capacity battery.

[0099] In addition, if each of the cells 610 is provided with an independent explosion release hole, the shared duct is not used as an electrolyte shared duct, and a sealing device can be provided at one end of the shared duct to inject electrolyte, and a blocking member 662 is provided at the other end. The sealing device should be provided with a valve and a joint for connecting an injection tube should be reserved in advance, and the sealing device should be made removable or an operation port should be reserved in advance in the sealing device so that the sealing mechanism can be opened in the shared duct through the operation port by using an opening tool.

[0100] When each cell 610 does not have an independent explosion relief hole, the common conduit can be used not only as an electrolyte common conduit but also as an explosion relief passage, and an explosion relief assembly 663 can be provided at one end of the common conduit, and a sealing device can be provided at the operation port at the other end, so that an opening tool for opening the sealing mechanism can enter from either end. Alternatively, a blocking member 662 can be provided at one end of the common conduit, and a removable explosion relief assembly 663 can be provided at the operation port at the other end. When injecting electrolyte through the common conduit, the explosion relief assembly 663 is removed to form an operation port, and the opening tool extends into the operation port to cut the sealing mechanism, and then the electrolyte is injected through the operation port. After the injection is completed, the explosion relief assembly 663 is restored, and when thermal runaway occurs in the large-capacity battery, the common conduit serves as an explosion relief passage, and smoke caused by thermal runaway is discharged by the explosion relief assembly 663.

[0101] One end of the shared duct is an operating port, and the other end can be sealed in advance by using a blocking member 662 or an explosion dissipation assembly 663 before the sealing mechanism is opened. The above-mentioned device can be removable or non-removable and is specifically provided according to specific requirements. After the sealing mechanism is opened, the sealing can also be performed by using a blocking member 662 or an explosion dissipation assembly 663. This is determined according to whether the conditions of the unpacking environment meet the specific requirements for unpacking the single cell 610. In general, the unpacking is preferably completed in an environment with a dew point standard between -25°C and -40°C, a temperature of 23°C±2°C, and a cleanliness level of 100,000. If the conditions can be met, the sealing of the shared duct can be adjusted according to a specific processing flow and program.

[0102] Example 6 22 to 25, the battery case provided in this embodiment includes a top cover assembly 32, a case body 31, and a sealing mechanism, the case body 31 is a case structure with one end open, the top cover assembly 32 and the case body 31 surround a battery case, and the case body 31 has an opening 311 communicating with its inner chamber. The sealing mechanism includes a connecting pipe 33 and a sealing film 34, the connecting pipe 33 is provided in the case body 31 and communicates with the inner chamber of the case body 31 through the opening 311, the connecting pipe 33 may be provided integrally with the case body 31, welded to the case body 31, or sealed by a flange. The sealing film 34 is provided in the opening 311 of the case body 31 to seal the case body 31 and prevent the electrolyte in the battery case from contacting the outside air. In addition, the sealing membrane 34 is provided on the side of the case body 31 away from the top cover assembly 32, and the top cover assembly 32 is provided with positive and negative poles. After the electrolytes in the multiple cells have circulated with each other, when the large-capacity battery is used, the top cover assembly 32 is positioned facing upward, and the liquid storage tube 36 and the connecting tube 33 are positioned facing downward.

[0103] When a large capacity battery is formed by connecting a plurality of single cells in parallel, the connecting pipes 33 and the liquid storage pipes 36 of the battery cases can be connected by abutting members, and the sealing membrane 34 needs to be opened in order to make the plurality of single cells have a uniform electrolyte system. At this time, a gas source can be externally connected to the connecting pipe 33, and the gas source fills the connecting pipe 33 with a high pressure gas, for example, an inert gas such as nitrogen gas, and the sealing membrane 34 is burst and opened by the pressure of the high pressure gas. In this manner, the sealing membrane 34 is prevented from coming into contact with water vapor or impurities in the air during the process of opening the sealing membrane 34. The electrolyte is injected into the battery case through the liquid storage pipe 36, and the electrolyte is injected from the outside to the inside of the battery case by the sealing mechanism, and the electrolyte in the plurality of batteries is realized to flow between each other, and the plurality of batteries are in a uniform electrolyte system, which greatly improves the consistency of the energy storage performance of each single cell, and improves the battery performance, yield and service life.

[0104] In this embodiment, the material of the sealing film 34 is at least one of copper, aluminum, PP, PE, and polytetrafluoroethylene. As shown in FIG. 24, in order to quickly open the sealing film 34, a notch 341 is provided in the sealing film 34, so that the sealing film 34 can be a weak part of the case body 31, and the opening of the sealing film 34 can be achieved at the notch 341. In another embodiment, the material of the sealing film 34 can be the same as that of the case body 31, and the sealing film 34 is integrally provided with the case body 31. The thickness of the sealing film 34 is smaller than the thickness of the case body 31, so that the sealing film 34 becomes a weak part of the case body 31.

[0105] Example 7 As shown in Figures 22, 26 and 27, the battery case provided in this embodiment includes a top cover assembly 32, a case body 31 and a sealing mechanism, and is different from Example 6 in that the sealing membrane 34 in this embodiment is installed in the connecting tube 33 to seal the battery case. An opening device 35 is installed in the connecting tube 33 in this embodiment, and the opening device 35 has a structure with a push-up protrusion or push-up spike at one end and a circular base at the other end, and the size of the circular base matches the inner diameter of the connecting tube 33, that is, the diameter of the circular base is the same as or slightly smaller than the inner diameter of the connecting tube 33, so that the opening device 35 can move in the connecting tube 33 under the action of external pressure. When the opening device 35 moves, the push-up protrusion or push-up spike of the opening device 35 can open the sealing membrane 34, so that the sealing membrane 34 is opened and the electrolyte is injected. Also, a notch can be provided in the center of the sealing membrane 34, and the notch can be opened by a push-up protrusion or push-up spike of the opening device 35, thereby realizing quick opening of the sealing membrane 34.

[0106] When a plurality of cells are connected in parallel to form a large-capacity battery, the connecting pipes 33 and the liquid storage pipes 36 of the plurality of battery cases can be connected by abutting members, a gas source is externally connected to the connecting pipes 33, and the gas source fills the connecting pipes 33 with high-pressure gas, for example, an inert gas such as nitrogen gas, and the opening device 35 moves inside the connecting pipes 33 by the pressure action of the high-pressure gas, and the sealing film 34 is opened by the opening device 35. This structure avoids contact with water vapor and impurities in the air during the process of opening the sealing film 34. Then, the liquid storage pipe 36 injects electrolyte into the battery case, so that the electrolyte in the plurality of batteries flows with each other, and the plurality of batteries are in a uniform electrolyte system, which greatly improves the consistency of the energy storage performance of each electrode assembly, and improves the battery performance, yield and service life.

[0107] In order to prevent the opening device 35 from being connected to the sealing membrane 34 after opening it and being unable to be separated from it, a pressure difference of -40mmHg can be created between the two sides of the opening device 35 in the liquid storage tube 36, and the opening device 35 can be separated from the sealing membrane 34 by extracting and suctioning in the opposite direction. If the opening device 35 and the sealing membrane 34 are already separated, the pressure difference of the negative pressure extraction and suction can be used to further expand the opening 311 opened in the sealing membrane 34. After the negative pressure extraction and suction is completed, the electrolyte is refilled. This ensures that each cell is immersed in the electrolyte together, thereby connecting the internal environments of the multiple cells together. Not only does it ensure that the electrical performance of each cell is the same, but the operating environment and the environment for immersing the electrolyte are also the same, which ensures the consistency of the electrical performance and operating conditions of all the cells, thereby greatly improving the service life of the large-capacity battery.

[0108] As shown in Fig. 27, in this embodiment, the opening device 35 opens the sealing membrane 34 of the battery under the action of external pressure to realize the electrolyte flow. The opening device 35 is installed in the connecting tube 33, and has a positioning boss 352 in the tube, which is used to position the opening device 35, and ensures that the opening device 35 opens the sealing membrane 34 without damaging the electrode assembly. When the opening device 35 opens the sealing membrane 34, the size of the opening device 35 can be set smaller than the diameter of the connecting tube 33, so that the electrolyte flows through the gap between the opening device 35 and the connecting tube 33. Or, when the connecting tube 33 is connected to the liquid storage tube 36, a part of the connecting tube 33 extends into the liquid storage tube 36. At this time, a through hole 331 can be provided in the connecting pipe 33 extending into the inside of the liquid storage pipe 36. After the opening device 35 opens the sealing film 34, the opening device 35 returns to the bottom of the connecting pipe 33. At this time, the opening device 35 blocks the bottom of the connecting pipe 33, and the electrolyte cannot flow in from the bottom of the connecting pipe 33. At this time, the electrolyte can be injected from the circumferential direction through the through hole 331, so as to ensure the sharing of the electrolyte between the large-capacity batteries. Naturally, at this time, it is required that the thickness of the circular base of the opening device 35 is smaller than the pipe diameter of the liquid storage pipe 36, and the circular base is located below the through hole 331 so as not to block the through hole 331.

[0109] In addition, as shown in FIG. 26, an explosion dissipation device 38 can be further provided in the liquid storage pipe 36 to exhaust smoke generated during thermal runaway of the large-capacity battery, and the explosion dissipation device 38 may specifically be an explosion dissipation valve.

[0110] Example 8 28 and 29, the battery case provided in this embodiment includes a top cover assembly 32, a case body 31, and a sealing mechanism, and is different from the sixth embodiment in that the sealing film 34 in this embodiment is provided in the opening 311 of the case body 31 or in the connecting tube 33 to seal the battery case. An opening device 35 is provided in the connecting tube 33, and the opening device 35 has a structure in which one end has a push-up protrusion or a push-up spike and the other end has a circular platform. The opening device 35 can move in the connecting tube 33 under the action of external pressure, so that the opening device 35 opens the sealing film 34. This opening method is a mechanical opening method, which is a method of opening the sealing film 34 by an external mechanical force. A sliding device may be provided in the liquid storage tube 36, and the sliding device is a sliding rod 37. The sliding rod 37 pushes the opening device 35 to slide in the connecting tube 33, and the opening device 35 opens the sealing film 34. In order to allow the electrolyte to flow more easily after the opening device 35 is pushed up, the opening device 35 may be a hollow opening device, with a through passage in the moving direction, through which the electrolyte can enter the battery case. In addition, the slide rod occupies part of the space inside the liquid storage tube 36, reducing the amount of electrolyte used.

[0111] As shown in Fig. 28, in order to move the opening device 35 quickly and accurately, a wedge-shaped surface 351 is provided on the end surface where the opening device 35 and the sliding device cooperate. When the sealing mechanism injects the electrolyte from the outside to the inside of the battery case, it operates in a sealed box or dry box environment, pushes the sliding rod 37 to slide inside the liquid storage tube 36, and pushes the hollow opening device 35 to the sealing membrane 34 to open the sealing membrane 34, so that the electrolyte enters the inside of the battery case. This structure avoids contact with water vapor and impurities in the air during the opening process of the sealing membrane 34. The material of the sealing membrane 34 is at least one of copper, aluminum, PP, PE, and polytetrafluoroethylene.

[0112] This embodiment further provides a large-capacity battery including a liquid storage tube 36 and a number of single cells, and the liquid storage tube 36 is connected to the connecting tubes 33 of the battery cases. Before the single cells are made into a large-capacity battery, the electric capacity, internal resistance, and charge / discharge characteristics of each electrode assembly are first tested. Only when the error of the above three parameters of each electrode assembly is within 1%, can they be matched in the same group. The connecting tube 33 and the liquid storage tube 36 are connected by abutting members. After the sealing film 34 is opened, the electrolyte is injected into the battery case through the liquid storage tube 36, so that the electrolyte in the multiple batteries can flow with each other, and the multiple batteries are in a uniform electrolyte system, which greatly improves the consistency of the energy storage performance of each electrode assembly, and improves the battery performance, yield and service life. In this embodiment, the sealing film 34 is opened by an external action force or external pressure in the connecting pipe 33. In this manner, it is possible to avoid opening the sealing film 34 in a state of contact with air, and it is possible to effectively prevent the battery case from coming into contact with moisture in the air when it is opened. The operation method is simple and reliable, has good water-proofing properties, does not increase other battery manufacturing processes, is easy to operate, improves battery performance and yield, has a simple structure, is easy to install, and has strong versatility.

[0113] Example 9 As shown in Figures 30 to 33, the battery case provided in this embodiment includes a case body 411 and a sealing mechanism, the case body 411 has an opening 414 communicating with its inner chamber, and the opening 414 may be a rectangular opening or a circular opening, the sealing mechanism includes a sealing layer 412 and a magnetic device 413, the sealing layer 412 is provided on the case body 411 and seals the opening 414, the magnetic device 413 is connected to the sealing layer 412 and is located on the side of the sealing layer 412 away from the case body 411, and when the magnetic device 413 is attracted by the magnetic member 44, at least a part of the sealing layer 412 is separated from the case body 411, the opening 414 is opened, and the electrolyte is injected from the opening 414.

[0114] In this embodiment, the magnetic device 413 is made of materials such as iron, cobalt, nickel, etc. The sealing layer 412 of the battery case 41 and the case body 411 are connected by adhesive, and the sealing layer 412 is one of PP, PE, and polytetrafluoroethylene. The magnetic device 413 is a magnetic bar, which is connected to the sealing layer 412 by a winding method, and adhesive can be provided between the sealing layer 412 and the magnetic bar for further fixation. In another embodiment, the sealing layer 412 is a self-adhesive tape with adhesive properties, and after the opening 414 of each battery case 41 is made, the self-adhesive tape is quickly directly attached to the case to seal the circular opening. The magnetic device 413 is a magnetic block, which is fixed to the sealing layer 412 by an adhesive method, and the reliability of the adhesion between the magnetic block and the sealing layer 412 needs to be stronger than that of the self-adhesive tape.

[0115] This embodiment further provides a cell 42, which includes an electrode assembly, an electrolyte, and the above-mentioned battery case 41, the electrode assembly and the electrolyte are both provided in the battery case 41, and the electrode assembly is immersed in the electrolyte. The opening 414 in the battery case 41 can be processed during the manufacture of the battery case 41, and after processing, it can be sealed with a sealing layer 412 and then injected with electrolyte to form the cell 42; alternatively, after the manufacture of the cell 42 is completed, the opening 414 can be opened in the battery case 41, and then quickly sealed with the sealing layer 412 in an environment with a dew point standard between -25°C and -40°C, a temperature of 23°C±2°C, and a cleanliness level of 100,000.

[0116] The sealing layer 412 and the magnetic bar are located on the outer surface of the top of the battery case 41, away from the tabs, and are in a state of high potential energy, and the magnetic bar can move freely without being affected by the gravity of each cell 42. After the battery case 41 is sealed, a strong magnet is quickly approached from the outside of the large-capacity battery to the magnetic bar connected to the sealing layer 412, and the magnetic attraction force is used to attract the internal magnetic bar to the outer inner wall of the battery chamber, and the impact kinetic energy generated by the attraction movement of the internal magnetic bar is used to break the sealing layer 412 and open the opening 414 of the battery case 41.

[0117] In addition, the magnetic devices 413 of the multiple battery cases 41 can be fixedly connected, or the magnetic devices 413 of the multiple battery cases 41 can be arranged in an integrated structure, that is, the multiple case bodies 411 adopt one magnetic device 413, and with such an arrangement, the multiple openings 414 can be opened simultaneously, and naturally, the multiple magnetic devices 413 can also be adopted to open the openings 414 respectively.

[0118] As shown in Fig. 34, this embodiment further provides a large-capacity battery including a battery box 43 and a plurality of cells 42, the cells 42 being soft-pack batteries, which are mainly formed by connecting in parallel a plurality of selected soft-pack batteries with the same electrical performance, and before each soft-pack battery to form a large-capacity lithium-ion battery is grouped, the electric capacity, internal resistance, and charge / discharge characteristics are tested, and each soft-pack battery can be grouped and matched only when the error of the above three parameters is within 1%. A plurality of selected soft-pack batteries with the same electrical performance (ignoring the selection error) are stacked, tightly pressed with a pressing plate, and tightly pressed by restraining belts. Before injecting the electrolyte, the large-capacity battery is provided with one long opening on the outer surface of the case body 411, which is separated from the tabs of all the soft-packed batteries, and the effective length of the long opening is 10 mm or more. After opening 414, each opening 414 is quickly sealed with the sealing layer 412. Then, the large-capacity battery is placed in the battery box 43, the sealing layer 412 and the magnetic rod of each soft-packed battery are securely connected, the conductive connection sheet, pole or plate of each single battery 42 are welded and connected in parallel, and finally, the battery box 43 is sealed. Next, the soft-packed battery is placed in the battery box 43, a magnetic block is attached to the self-adhesive tape attached to each soft-packed battery, and finally, the cavity of the battery box 43 is sealed.

[0119] When performing pre-filling and capacity grading of the large-capacity battery, a strong magnet is used to quickly approach the magnetic bar located in the cavity of the battery box 43 and fixedly connected to the sealing layer 412 from the outside of the battery box 43, and the magnetic bar is attracted to the outer inner wall of the battery chamber using magnetic attraction, and the impact kinetic energy of the magnetic bar's attraction motion is used to break the seal of each opening 414 of the sealing layer 412, so that the openings 414 of each cell 42 are opened. During the magnetic attraction process, the sealing layer 412 and the magnetic bar are located at the top of the case body 411 to prevent the magnetic bar from being pushed by the gravity of the internal soft-pack battery and affecting the movement of the magnetic bar. After each opening 414 is opened, -40mmHg extraction and suction are performed against the internal environment of the battery box 43, forming a pressure difference between the inner and outer layers of the battery case 41, and the pressure difference of the negative pressure extraction and suction is used to further expand the openings 414 in the battery case 41. After the negative pressure extraction and suction is completed, the electrolyte is refilled. This ensures that each soft-pack battery is immersed in the electrolyte, thereby connecting the internal environment of the cells 42 with that of the battery box 43. Not only does it ensure that the electrical performance of each cell 42 is the same (guaranteed by the grouping in the previous test), but it also ensures that the operating environment and electrolyte soaking environment are the same, thereby ensuring the consistency of the electrical performance and operating conditions of all the cells 42, and thereby greatly improving the service life of the large-capacity battery.

[0120] After the large-capacity battery operates normally, the expansion caused by temperature rise and the generation of internal gas work together to make the passage of the long hole smoother, thereby connecting the inside of the cells 42 with the inside environment of the battery box 43. The positions, lengths and depths of the openings 414 of the cells 42 can be kept consistent, and when the large-capacity battery is placed after completion of negative pressure extraction suction and electrolyte injection, it must be ensured that the openings 414 of each soft-pack battery are located at the lowest position in the battery inner chamber, so that each soft-pack battery can be easily soaked with electrolyte.

[0121] Example 10 As shown in Figures 35 to 38, this embodiment provides a battery case, which includes a case body 51, a hot melt layer 52, and a heating device 54, and the case body 51 has an opening 53 communicating with its inner chamber, and the hot melt layer 52 seals the opening 53. When the hot melt layer 52 receives heat and melts, the opening 53 is opened and the electrolyte is injected through the opening 53. In this embodiment, the hot melt layer 52 is a hot melt tape, which is adhered to the opening 53 and covers the opening 53, the hot melt tape is made of polypropylene, has a melting point of 189°C, and softens when the temperature reaches 155°C, or the hot melt tape is made of polyethylene, has a melting point of 135°C, and softens when the temperature reaches 125°C, in this embodiment, the heating device 54 is a heating wire or heating belt, the heating wire is provided on the center line of the hot melt tape, the heating belt is provided in close contact with the hot melt tape, the heating wire or heating belt is connected to an external power source via a conductive wire 58, the heating wire or heating belt is heated when energized and transfers heat to the hot melt tape, and when the temperature reaches the melting point of the hot melt tape, the hot melt tape melts and the opening 53 is opened. According to actual needs, the heating device 54 in this embodiment may be a heating sheet.

[0122] In this embodiment, a heating device 54 is provided, and the opening 53 of the battery case is opened by utilizing the melting of the hot melt layer 52, so that the electrolyte in the battery and the electrolyte in the single cell can flow with each other. This makes the performance of the electrolyte in the battery uniform and consistent, and facilitates pre-filling the battery and refilling after capacity grading, making the operation easy and flexible.

[0123] This embodiment shows a single cell including the above-mentioned battery case, an electrode assembly 55, and an electrolyte, where the electrode assembly 55 is disposed in the battery case and immersed in the electrolyte.

[0124] This embodiment shows a large-capacity battery including several single cells and a battery box 56, and the single cells are arranged in the battery box 56. When a large-capacity battery is assembled using a plurality of single cells, the electrolyte in the battery box 56 and the electrolyte in the single cells are mutually circulated, the performance of the electrolyte in the battery is uniform and consistent, the battery is easy to prefill and replenish after capacity grading, the service life of the battery is improved, the operability is strong, the cost is low, and the production efficiency and yield of the battery are improved. The battery box 56 is provided with an injection explosion release port 57, and an explosion release valve is provided in the injection explosion release port 57. The heating device 54 is connected to the power source externally through the conductive wire 58 to heat the battery. When the battery is injected or replenished, the electrolyte is injected from the injection explosion release port 57, and when thermal runaway occurs, the explosion release valve is opened to discharge the electrolyte and the gas caused by thermal runaway from the injection explosion release port 57, so that the battery can be prevented from burning or exploding.

[0125] This embodiment shows a method for sharing the electrolyte of a battery, which includes the following steps. In S100, seven soft-pack cells are connected in parallel to form a soft-pack cell group, which is then arranged in a battery box 56, and then the conductive wire 58 of the heating device 54 is drawn out from the liquid injection explosion dissipation port 57 and externally connected to a power source. It should be noted that the number of soft-pack cells can be adjusted according to the demand for battery capacity. In this embodiment, the heating device 54 is a heating wire, and the conductive wire 58 is a soft structure and can be drawn out from the liquid injection explosion dissipation port 57. In S200, when the heating device 54 is energized, it generates heat and conducts the heat to the hot melt layer 52, and the hot melt layer 52 is at least partially melted. In this embodiment, the hot melt layer 52 is a hot melt tape, which is adhered to the opening 53 and covers the opening 53. The material of the hot melt tape is polyethylene, which has a melting point of 135°C and softens when the temperature reaches 125°C. In S300, the conductive wire 58 and the heating device 54 are pulled out from the liquid injection explosion release port 57. The conductive wire 58 pulls out the heating device 54 and the hot melt layer 52 attached to the heating device 54 together, and the opening 53 of the battery case can be opened. In S400, electrolyte is injected into the battery box 56 from the liquid injection explosion release port 57, and the electrolyte in the battery box 56 and the electrolyte in the soft-pack cell are allowed to flow mutually. In S500, an explosion release valve is attached to the liquid injection explosion release port 57. After the explosion release valve is attached, the entire battery is sealed.

[0126] This method allows the electrolyte in the battery box 56 and the electrolyte in the soft-pack cell to flow between each other, realizing sharing of the electrolyte and making the performance of the electrolyte in the entire battery uniform and consistent. It is also easy to prefill the battery and to replenish the electrolyte after capacity grading, improving the service life of the battery, making it easy to operate and inexpensive, and improving the production efficiency and yield of the battery.

Claims

1. a sealing mechanism and an opening communicating with the inner chamber of the battery case are provided, the sealing mechanism seals the opening, and the sealing mechanism can be opened by an external force; A battery case characterized by:

2. The sealing mechanism includes a sealing part that is installed to seal the opening, and a pulling part that is connected to a side surface of the sealing part that is away from the opening, and when the pulling part is pulled by an external force, the entire sealing part is detached from the opening, or an opening is formed in the sealing part.

2. The battery case according to claim 1 .

3. A cut is provided around the sealing portion, and the area surrounded by the cut is a weakened area. A traction portion is provided in the weakened area. When the traction portion is pulled by an external force, the weakened area tears along the cut to form an opening.

3. The battery case according to claim 2.

4. The shape of the weakened area is teardrop-shaped, circular, or running track-shaped, the cross section of the cut is U-shaped or V-shaped, the weakened area is located at the center of the sealing portion, and the traction portion is eccentrically provided to the weakened area.

4. The battery case according to claim 3.

5. The battery case is provided with a conduit extending along a thickness direction of the battery case, the conduit covering the opening.

5. The battery case according to claim 4.

6. The battery case includes an upper cover plate, a lower cover plate, and a cylinder, the upper cover plate being provided with a positive electrode pole and a negative electrode pole, and the opening being provided in the lower cover plate.

3. The battery case according to claim 2.

7. the sealing mechanism includes a fixing part and a liquid injection part, the fixing part is a sheet-like structure having a through hole for fixing the sealing mechanism to the battery case, the liquid injection part is a hollow tubular structure having an open end and a closed end, the open end is fixed to the through hole so as to communicate between the liquid injection part and the inner chamber of the battery case, and the closed end is used to inject an electrolyte into the inner chamber of the battery case after being opened by the action of an external force; 2. The battery case according to claim 1 .

8. A protruding positioning portion is provided on a side of the through hole facing the liquid injection portion, and a weakened groove is provided along a circumferential direction of the liquid injection portion, and the weakened groove is provided at one end of the liquid injection portion away from the fixed portion. The battery case according to claim 7 .

9. The battery case according to any one of claims 2 to 8, 1. A battery comprising:

10. an electrode assembly is provided in the battery case, the battery case is provided with a conduit extending along a thickness or width direction of the cell and having a passage in a side wall, and the sealing mechanism is provided at an opening of the battery case corresponding to the passage; 10. The cell according to claim 9 .

11. A number of soft-pack batteries connected in parallel are provided in the battery case, and each of the cases of the soft-pack batteries is provided with an opening. The battery case is provided with a conduit extending along the thickness or width direction of the cell and having a passage in its side wall, and the sealing mechanism is provided at the opening of the battery case corresponding to the passage.

10. The cell according to claim 9 .

12. A rectangular battery is provided in the battery case, an opening is provided in the rectangular battery case, a conduit is provided in the battery case that extends along the thickness or width direction of the cell and has a passage in a side wall, and the sealing mechanism is provided in the opening of the battery case that corresponds to the passage, or the sealing mechanism is provided in the opening of the rectangular battery case.

10. The cell according to claim 9 .

13. 13. A battery comprising several cells according to any one of claims 9 to 12, the several cells being connected in parallel and communicating with each other through a common pipe. A large capacity battery characterized by:

14. The ducts in two adjacent cells are connected by one connecting member to form a shared duct, and the inside of the connecting member is hollow and penetrates through the ducts.

14. The large capacity battery according to claim 13.

15. A method for producing a large-capacity battery according to claim 13 or 14, comprising the steps of: Fixing several cells having a sealing mechanism into a group, the several cells in the group having one common conduit; Using a port at any one end of the common duct as an access port, and using an unpacking tool to open the sealing mechanisms of all the cells, penetrating the inner chambers of all the cells and the common duct; injecting electrolyte into the common conduit and allowing the electrolyte to enter the interior chamber of each cell, so that all the cells are in the same electrolyte system; A method for producing a large-capacity battery.

16. the opening tool includes an elongated rod having a cutting portion for cutting the sealed end of the closure mechanism, the cutting portion being a hollow circular tube having an open end, the open end of the hollow circular tube having a serrated blade or the open end of the hollow circular tube being wedge shaped; The method for producing a large-capacity battery according to claim 15.

17. The battery case is mainly formed by being surrounded by a top cover assembly and a case body, the case body is provided with an opening communicating with its inner chamber, the sealing mechanism includes a connecting pipe and a sealing membrane, the connecting pipe is provided in the case body and communicates with the inner chamber of the case body through the opening, the sealing membrane is provided in the opening of the case body or in the connecting pipe to seal the battery case, and the sealing membrane is opened by an external force or external pressure in the connecting pipe so that the electrolyte can enter the case body.

2. The battery case according to claim 1 .

18. An opening device is provided in the connecting pipe, and the opening device can move in the connecting pipe under the action of an external pressure or a sliding device, and the sealing membrane is opened by the opening device.

18. The battery case according to claim 17.

19. The opening device has a push-up protrusion or a push-up spike at one end and a circular base at the other end.

20. The battery case according to claim 18.

20. A side wall of the circular platform of the opening device is provided with a wedge-shaped surface for cooperating with the sliding device, and a plurality of through holes for circumferential injection of the electrolyte are provided along the circumferential direction on the side wall at one end away from the opening of the connecting pipe, and a passage is provided inside the opening device along the moving direction thereof.

20. The battery case according to claim 19.

21. A battery comprising an electrode assembly and the battery case according to any one of claims 17 to 20, wherein the electrode assembly is disposed in the battery case and immersed in an electrolyte.

1. A battery comprising:

22. A liquid storage tube and a plurality of the single batteries according to claim 21, the liquid storage tube being in communication with any of the connection tubes of the plurality of battery cases, a slide device being a slide rod being provided in the liquid storage tube, the slide rod being used to push the opening device to slide into the connection tube so that the opening device opens the sealing membrane. A large capacity battery characterized by:

23. The liquid storage pipe is provided with a liquid injection device which is a liquid injection valve, and the liquid storage pipe is further provided with an explosion dissipation device for discharging smoke generated when the large-capacity battery experiences thermal runaway.

23. The large capacity battery according to claim 22.

24. the sealing mechanism includes a sealing layer and a magnetic device, the sealing layer is provided on the case body of the battery case and seals the opening, the magnetic device is connected to the sealing layer and is located on a side of the sealing layer away from the case body, and when the magnetic device is attracted by a magnetic member, at least a part of the sealing layer is separated from the case body, the opening is opened, and an electrolyte is injected through the opening.

2. The battery case according to claim 1 .

25. The sealing layer and the case body are connected by adhesive, or the sealing layer is a self-adhesive tape; 25. The battery case according to claim 24.

26. The magnetic device is a magnetic bar connected to the sealing layer by a winding manner, or the magnetic device is a magnetic block fixed to the sealing layer by an adhesive manner.

25. The battery case according to claim 24.

27. The sealing mechanism is a hot melt layer, an opening communicating with the inner chamber of the case body of the battery case is provided in the case body, the hot melt layer seals the opening, and a heating device is provided in the hot melt layer. When the hot melt layer is heated and melted, the opening is opened and an electrolyte is injected from the opening.

2. The battery case according to claim 1 .

28. The heating device is one of a heating wire, a heating sheet or a heating belt, the heating device is connected to an external power source through a conductive wire, and the hot melt layer is a hot melt tape; 28. The battery case according to claim 27.

29. A battery comprising an electrode assembly, an electrolyte, and the battery case according to any one of claims 24 to 28, wherein the electrode assembly and the electrolyte are both provided in the battery case, and the electrode assembly is immersed in the electrolyte.

1. A battery comprising:

30. a battery box and a plurality of the unit cells according to claim 29, the unit cells being provided in the battery box, and an electrolyte in the battery box and an electrolyte in a battery case being in fluid communication with each other through an opening; A large capacity battery characterized by:

31. The battery box is provided with an injection explosion relief port provided with an explosion relief valve.

31. The large capacity battery according to claim 30.

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