High-capacity battery

Abstract

The utility model belongs to the field of batteries, and particularly relates to a high-capacity battery. The safety problem caused by the fact that thermal runaway smoke of an existing high-capacity battery leaks between an upper cover plate of a single battery and a cylinder body of the single battery easily, and the thermal runaway smoke diffuses is solved. The high-capacity battery comprises a shell, and at least one first clamping plate, at least one second clamping plate and n single batteries which are positioned in the shell, the n single batteries are arranged in the inner cavity of the shell along the same direction; the first clamping plate is matched with the first side plate of the box body and clamps each single battery in the y direction; the second clamping plate is matched with the second side plate of the box body and clamps each single battery in the x direction; when thermal runaway occurs, due to the clamping effect of the first clamping plate and the second clamping plate, the problem that the single battery deforms in the x and y directions, a crack occurs between the upper cover plate and the single battery cylinder, and smoke spreads from the crack can be avoided.

Description

Technical Field

[0001] The utility model belongs to the field of batteries, in particular to a large-capacity battery. Background Art

[0002] Currently, multiple single cells are connected in parallel, in series, or in series-parallel mode to form a large-capacity battery (also called a battery module or battery pack).

[0003] However, the individual cells in existing large-capacity batteries are different from each other. Due to the existence of the barrel effect, they are often affected by the cell with the worst performance, which greatly limits the capacity limit and cycle times of the entire large-capacity battery. Therefore, how to improve the uniformity of each cell in a large-capacity battery has become the focus and difficulty of research in this field.

[0004] In order to solve the above problems, Chinese patent CN220324596U discloses a large-capacity battery, the structure of which is as follows Figure 1 As shown, such a large-capacity battery includes a housing 1 and a plurality of single cells 2;

[0005] Define the length direction of the shell as the x direction, the width direction as the y direction, and the height direction as the z direction;

[0006] A plurality of single cells are connected in parallel in sequence and arranged in the inner cavity of the shell along the x direction; in the shell, the second side walls of the single cells are parallel to each other and parallel to the yz plane.

[0007] The housing comprises a box body 11, a first cover plate 13 and a second cover plate 12;

[0008] The first cover plate 13 is provided with an electrolyte sharing chamber 7, which covers the open end of the bottom of the box body and is sealed and connected to the open end; the electrolyte sharing chamber is connected to the electrolyte area of ​​the inner cavity of each single battery;

[0009] The electrolytes in the inner cavities of each single cell are connected through an electrolyte sharing chamber, so that the electrolytes of all single cells are in the same system, reducing the differences between the electrolytes of each single cell and improving the consistency between the single cells to a certain extent, thereby improving the cycle life of large-capacity batteries to a certain extent.

[0010] The second cover plate 12 is provided with avoidance holes that allow the polarity terminals of each single battery to extend out; the second cover plate covers the open end of the top of the box body and is sealed and connected to the open end; the polarity terminals of each single battery extend out of the avoidance holes and the second cover plate area corresponding to the avoidance holes is fixedly sealed with the single battery housing;

[0011] It should be noted that the above-mentioned single cell polarity terminal can be a single cell pole. If, in order to avoid the single cell pole being unable to smoothly extend out of the avoidance hole as a polarity terminal or the height of the extended avoidance hole does not meet the set requirements, a pole adapter can also be connected to the single cell pole, and the overall structure of the single cell pole and the pole adapter can be used as the single cell polarity terminal.

[0012] In addition, a gas chamber is also provided on the second cover plate, and the gas chamber covers the gas opening on the top of each single battery.

[0013] It should be noted that the gas port here includes the following two meanings:

[0014] 1) The gas port is a through hole directly opened on the upper cover plate of the single cell and penetrating the inner cavity of the single cell;

[0015] At this time, the inner cavity of the gas chamber is connected with the gas area of ​​the inner cavity of each single cell through the gas port. Based on the gas chamber, the gas area of ​​each single cell can be connected to achieve gas balance, so that the gas of each single cell is shared to ensure the consistency of each single cell, which improves the cycle life of the large-capacity battery to a certain extent; when any single cell has thermal runaway, the smoke in the inner cavity of the single cell enters the gas chamber and is discharged through the gas chamber, thereby improving the safety of the large-capacity battery.

[0016] 2) The gas port is an explosion vent or explosion-proof port provided on the upper cover plate of the single cell, and an explosion vent membrane is provided at the explosion vent or explosion-proof port;

[0017] At this time, the gas chamber is used as an explosion-proof channel. When the explosion-proof membrane at the gas port of any single battery is broken by the inner cavity smoke, the inner cavity of the single battery and the gas chamber are connected, and the internal smoke is discharged through the gas chamber, thereby improving the safety of the large-capacity battery.

[0018] When multiple large-capacity batteries as described above are assembled into an energy storage device, the explosion relief mechanism of each large-capacity battery (the explosion relief mechanism is a pipe section fixed on the outer casing and connected to the inner cavity of the electrolyte shared chamber and / or the gas chamber, and an explosion relief membrane is fixed in the pipe section) is usually connected to an explosion relief manifold, and the outlet end of the explosion relief manifold is led out of the energy storage device box. When any single cell in the large-capacity battery has thermal runaway, the thermal runaway smoke is discharged from the energy storage device box through the gas port of the single cell, the explosion relief mechanism, and the explosion relief manifold in sequence, so as to avoid safety accidents caused by the thermal runaway smoke spreading to the entire energy storage device box after thermal runaway occurs.

[0019] However, it has been verified through experiments that when thermal runaway occurs in individual cells of the above-mentioned large-capacity battery, the thermal runaway smoke will leak from the weld between the upper cover plate of the cell and the cylinder of the cell. Therefore, if the above-mentioned multiple large-capacity batteries are used to assemble an energy storage device, when thermal runaway occurs, the thermal runaway smoke will not only be discharged through the gas port and the explosion relief mechanism into the explosion relief manifold, but may also leak from the weld between the upper cover plate of the cell and its cylinder, and diffuse into the large-capacity battery shell, increasing the pressure in the shell cavity, which is easy to cause the weld between the box body and the first cover plate and the second cover plate, as well as the second cover plate area around the avoidance hole to tear, which may cause the large-capacity battery or even the energy storage device to burst in severe cases. Summary of the invention

[0020] The utility model aims to provide a large-capacity battery, which overcomes the safety problem caused by the thermal runaway smoke of the existing large-capacity battery easily leaking from between the upper cover plate of the single battery and the single battery cylinder, resulting in the diffusion of the thermal runaway smoke.

[0021] The idea of ​​the utility model is:

[0022] Based on the problems existing in the background technology, the large-capacity battery after thermal runaway was disassembled, and it was found that cracks appeared between the upper cover plate and the cylinder of the single battery with thermal runaway. After analysis, the reason for this phenomenon is:

[0023] The above-mentioned large-capacity battery casing comprises a box body with open ends at the top and bottom, and a first cover plate and a second cover plate respectively fixed to the two open ends of the box body; in the process of assembling the large-capacity battery, the first cover plate is fixed to the open end at the bottom of the box body (the first cover plate and the box body may also be an integral part), each single battery is placed from the open end at the top of the box body, and then the second cover plate is fixed to the open end at the top of the box body;

[0024] In order to facilitate the placement of each single cell into the box, in the x direction, the size of the box needs to be slightly larger than the sum of the thicknesses of multiple single cells; after assembly, there is a certain gap between the second side wall of the outermost single cell and the second side plate of the box (the second side wall of the single cell is a side wall parallel to the yz plane, and the second side plate of the box is a side plate parallel to the yz plane); in the y direction, the size of the box needs to be slightly larger than the width of the single cell; after assembly, there is a certain gap between the first side wall of the single cell and the first side plate of the box (the first side wall of the single cell is a side wall parallel to the xz plane, and the first side plate of the box is a side plate parallel to the xz plane); it is precisely because of the existence of the above-mentioned gap that when thermal runaway occurs, the restraining force of the single cell in the x and y directions is small, and it is easy to deform under the action of internal pressure, which leads to tearing of the upper cover plate and the first and second side walls of the single cell, and then causes the thermal runaway smoke to leak from the torn part.

[0025] In addition, the above-mentioned large-capacity battery can be provided with a sealing connector between the avoidance hole and the polarity terminal to achieve fixed sealing between the second cover plate area corresponding to the avoidance hole and the single cell housing; such sealing connector includes a hollow component; the hollow component is sleeved on the outside of the single cell polarity terminal, the bottom of the hollow component is sealed and connected to the upper cover plate area around the single cell polarity terminal, and the top of the hollow component is sealed and connected to the second cover plate area corresponding to the avoidance hole; due to the existence of the sealing connector, in the z direction, the sealing connector cooperates with the second cover plate and the first cover plate, and can also apply a clamping force to each single cell; when thermal runaway occurs, the single cell can be prevented from deforming in the z direction, and the problem of cracks between the upper cover plate and the cylinder can be avoided;

[0026] In summary, for the above-mentioned large-capacity battery, in the z direction, the sealing connector cooperates with the second cover plate and the first cover plate to support each single cell. When thermal runaway occurs, the deformation of the single cell in the z direction due to the internal pressure can be avoided, which leads to the problem of cracks between the upper cover plate and the cylinder. However, in the x and y directions, due to the gap between the single cell and the box body, when thermal runaway occurs, the single cell is easy to deform in the x and y directions, which leads to cracks between the upper cover plate and the single cell cylinder, causing the problem of thermal runaway smoke leakage from the cracks.

[0027] Based on the above analysis, the utility model applies clamping force to each single cell in the x and y directions, so that the single cells in the large-capacity battery are constrained in the x, y and z directions, ensuring that the thermal runaway smoke can be smoothly released from the explosion relief mechanism, reducing or even avoiding the problem of tearing of the single cell shell when the single cell is in thermal runaway, resulting in aggravated thermal runaway and smoke spread.

[0028] Therefore, the utility model proposes the following technical solutions:

[0029] A large-capacity battery, which is special in that it comprises a housing, at least one first clamping plate, at least one second clamping plate and n single cells located in the housing; wherein n is an integer greater than 1;

[0030] n single cells are arranged in the same direction in the inner cavity of the housing; the inner cavity of each single cell includes an electrolyte area and a gas area;

[0031] The housing comprises a box body, a first cover plate and a second cover plate;

[0032] The bottom and top of the box are open;

[0033] An electrolyte sharing chamber is provided on the first cover plate, and the first cover plate covers the open end of the bottom of the box body and is sealed and connected to the open end; the inner cavity of the electrolyte sharing chamber is connected to the electrolyte area of ​​the inner cavity of each single battery;

[0034] The second cover plate is provided with avoidance holes through which the polarity terminals of each single battery can be extended; the second cover plate covers the open end of the top of the box body and is sealed and connected to the open end; the polarity terminals of each single battery extend out of the avoidance holes, and the second cover plate area corresponding to the avoidance holes is fixedly sealed with the single battery housing;

[0035] The first clamping plate is disposed between the first side plate of the box body and the first side wall of each single cell, and the two surfaces of the first clamping plate are respectively in close contact with the first side plate of the box body and the first side wall of each single cell, wherein the first side plate of the box body and the first side wall of each single cell are parallel to the xz plane;

[0036] The second clamping plate is arranged between the second side plate of the box body and the second side wall of the outermost single cell, and the two surfaces of the second clamping plate are respectively in close contact with the second side plate of the box body and the second side wall of the outermost single cell, wherein the second side plate of the box body and the second side wall of the single cell are both parallel to the yz plane.

[0037] The utility model provides a first clamping plate and a second clamping plate on a large-capacity battery shell, wherein the first clamping plate cooperates with the first side plate of the box body to clamp each single battery from the y direction; the second clamping plate cooperates with the second side plate of the box body to clamp each single battery from the x direction; when thermal runaway occurs, due to the clamping effect of the first clamping plate and the second clamping plate, deformation of the single battery in the x and y directions can be avoided, cracks can be formed between the upper cover plate and the single battery cylinder, and the problem of smoke spreading from the cracks can be avoided.

[0038] Furthermore, there are two first clamping plates, which are respectively located between the two first side plates of the box body and the first side walls of each single cell opposite thereto; in the y direction, the single cell is clamped from the two opposite first side walls of the single cell.

[0039] Furthermore, one of the first clamping plates includes n first sub-clamping plates, each of which corresponds to a single cell one by one, and in the x direction, the size of each first sub-clamping plate is equal to the size of the first side wall of the single cell; the other first clamping plate is a whole flat plate. When the size deviation of each single cell in the y direction is large, first sub-clamping plates of different thicknesses can be selected according to the spacing between the first side plate of the single cell and the first side wall of the box body, thereby ensuring that all single cells are clamped in the y direction.

[0040] Furthermore, in the z direction, the size of the first clamping plate is equal to the size of the first side wall of the single battery, so as to ensure that the single battery is evenly stressed.

[0041] Furthermore, there are two second clamping plates, and the two second clamping plates are respectively located between the second side walls of the two outermost single cells and the second side plates of the box body opposite thereto.

[0042] Furthermore, the box body also includes a plurality of partitions arranged in the inner cavity of the box body, dividing the inner cavity of the box body into a plurality of single cell installation cavities; a single cell is fixed in each single cell installation cavity;

[0043] The first clamping plate includes at least n first sub-clamping plates, and the n first sub-clamping plates correspond to the n single cells one by one; a first sub-clamping plate is arranged between the first side wall of each single cell and the first side plate of the box body;

[0044] There are at least n second clamping plates, and a second clamping plate is arranged between at least one second side wall of each single battery and a corresponding partition plate.

[0045] Furthermore, there are 2n first sub-clamping plates, and one first sub-clamping plate is arranged between the two first side walls of each single battery and the corresponding first side plate of the box body.

[0046] In this solution, the heat generated during the charging and discharging process of each single cell can be transmitted to the outside through the partition and the second clamping plate, reducing the risk of thermal runaway. In addition, the partition can also enhance the strength of the box.

[0047] Furthermore, there are 2n second clamping plates, and a second clamping plate is provided between the two second side walls of each single battery and the corresponding partition plate and the second side plate of the box body.

[0048] Furthermore, the above-mentioned large-capacity battery also includes 2n sealing connectors; the second cover plate area corresponding to each avoidance hole is fixedly sealed with the single cell shell by a sealing connector; the sealing connector includes a hollow component sleeved on the outside of the polarity terminal of the single cell, and the orthographic projection of the open end of the bottom of the hollow component on the upper cover of the single cell covers the weak area around the polarity terminal on the upper cover of the single cell; the bottom of the hollow component and the outer area of ​​the weak area are welded and sealed, and the top of the hollow component and the second cover plate area corresponding to the avoidance hole are welded and sealed.

[0049] When in use, the hollow component is sleeved on the outside of the polarity terminal of the single cell, the bottom and the outer area of ​​the weak area are welded and sealed, and the top of the hollow component and the second cover plate area around the avoidance hole are welded and sealed. Regardless of whether there is a gap between the second cover plate and the upper cover plates of each single cell, or whether the gap sizes are different, the hollow component can seal and fix the second cover plate and the upper cover plate of the single cell, thereby ensuring the sealing of the large-capacity battery shell; at the same time, by optimizing the size and shape of the bottom open end of the sealing connector, the orthographic projection of the bottom open end of the hollow component on the upper cover plate of the single cell covers the weak area around the polarity terminal of the upper cover plate of the single cell; thereby ensuring that when welding the bottom of the hollow component and the area around the polarity terminal of the upper cover plate of the single cell, the weak area around the polarity terminal of the upper cover plate of the single cell can be avoided, thereby avoiding damage to the weak area during the welding process, thereby avoiding a series of problems such as the scrapping of the single cell and the diffusion of thermal runaway smoke.

[0050] Furthermore, the sealing connector also includes a bottom plate fixed to the open end of the bottom of the hollow component; a third through hole is opened on the bottom plate; the third through hole covers the weak area around the polarity terminal on the upper cover plate of the single cell through an orthographic projection on the upper cover plate of the single cell; the bottom plate is used for welding and sealing with the peripheral area of ​​the weak area.

[0051] Based on the bottom plate, the upper cover plate and the sealing connector can be reliably welded, and at the same time, the orthographic projection of the third through hole on the upper cover plate of the single cell covers the weak area around the polarity terminal on the upper cover plate of the single cell; thus, when the bottom plate and the upper cover plate of the single cell are welded, the welding part must be located outside the weak area. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 It is a structural schematic diagram of a large-capacity battery in the background technology;

[0053] Figure 2 This is a schematic diagram of the explosion structure of a large-capacity battery in Example 1;

[0054] Figure 3 is a cross-sectional view of a large-capacity battery in Example 1;

[0055] Figure 4 for Figure 3 Enlarged view of area a in the middle;

[0056] Figure 5 This is a schematic diagram of the explosion structure of a large-capacity battery in Example 2;

[0057] Figure 6 This is a schematic diagram of the partial structure of a large-capacity battery in Example 3;

[0058] Figure 7 This is a schematic diagram of the installation process of a large-capacity battery in Example 3;

[0059] Figure 8 is a schematic structural diagram of the sealing connector in Example 4;

[0060] Fig. 9 Schematic diagram of the structure of the sealing connector with a bottom plate in Example 4 Figure 1 ;

[0061] Fig.10 Schematic diagram of the structure of the sealing connector with a bottom plate in Example 4 Figure 2 ;

[0062] Fig.11 It is a schematic structural diagram of a sealing connector provided with a second annular plate;

[0063] Fig.12 It is a schematic structural diagram of a sealing connector provided with a first annular plate;

[0064] The accompanying drawings in the figure are marked as follows:

[0065] 1. Shell; 11. Box body; 12. Second cover plate; 13. First cover plate; 2. Single cell; 21. Pole; 22. Pole adapter; 31. First clamping plate; 311. First sub-clamping plate; 32. Second clamping plate; 4. Avoidance hole; 5. Partition; 6. Sealing connector; 181. Hollow member; 1811. Bottom open end; 1812. Top open end; 182. Bottom plate; 1820. Third through hole; 183. Second annular plate; 184. First annular plate; 7. Electrolyte shared chamber; 8. Gas chamber. DETAILED DESCRIPTION

[0066] In order to make the above-mentioned purposes, features and advantages of the utility model more obvious and easy to understand, the specific implementation methods of the utility model are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the utility model, but not all of them. Based on the embodiments of the utility model, all other embodiments obtained by ordinary persons in the field without creative work should fall within the scope of protection of the utility model.

[0067] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0068] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "top, bottom" etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first, second, third, fourth, etc." are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0069] The utility model discloses a large-capacity battery, comprising a shell and n single cells, wherein n is an integer greater than 1; the n single cells are arranged in the same direction and placed in the shell.

[0070] A rectangular shell is usually used. For ease of description, the length direction of the shell is defined as the x direction, the width direction of the shell is defined as the y direction, and the height direction of the shell is defined as the z direction.

[0071] The housing of the utility model comprises a box body with open ends at the top and bottom (i.e., the ports parallel to the xy plane are open ends) and a second cover plate and a first cover plate respectively fixed to the open ends at the top and bottom of the box body (i.e., the second cover plate and the first cover plate are parallel to the xy plane);

[0072] The first cover plate is provided with an electrolyte sharing chamber extending at least along the x-direction. The inner cavity of the electrolyte sharing chamber is connected to the inner cavity of each single cell. Through the electrolyte sharing chamber, each single cell can be placed in a unified electrolyte environment, ensuring the uniformity of the electrolyte in each single cell; improving the performance and charge-discharge cycle life of large-capacity batteries. The electrolyte sharing chamber described here is a liquid channel extending along the length direction of the x-direction on the first cover plate. The liquid channel can be integrally formed with the first cover plate, or formed by arranging a hollow tube on the outer surface of the first cover plate (through holes need to be opened in the hollow tube and the first cover plate, and the inner cavity of the single cell and the inner cavity of the hollow tube are connected based on the through holes).

[0073] A gas chamber may also be provided on the second cover plate, and the gas chamber covers the gas port on the top of each single cell in the large-capacity battery. It should be noted that the gas port here includes the following two meanings:

[0074] 1) The gas port is a first through hole directly opened on the upper cover plate of the single cell and penetrating the inner cavity of the single cell;

[0075] At this time, the inner cavity of the gas chamber is connected with the gas area of ​​the inner cavity of each single cell through the gas port. The gas chamber serves as a gas sharing chamber for each single cell. Based on the gas chamber, the gas areas of each single cell can be connected to achieve gas balance, so that the gas of each single cell is shared to ensure the consistency of each single cell, which improves the cycle life of the large-capacity battery to a certain extent; when any single cell has thermal runaway, the smoke in the inner cavity of the single cell enters the gas chamber and is discharged through the gas chamber, thereby improving the safety of the large-capacity battery.

[0076] 2) The gas port is an explosion vent or explosion-proof port provided on the upper cover plate of the single cell, and an explosion vent membrane is provided at the explosion vent or explosion-proof port;

[0077] At this time, the gas chamber is used as an explosion relief channel. When the explosion relief membrane at the gas outlet of any single cell is broken by the internal smoke, the internal cavity of the single cell is connected to the gas chamber, and the internal smoke is discharged through the gas chamber, thereby improving the safety of the large-capacity battery. The above-mentioned shared chamber can also be a gas chamber, and the gas balance of each single cell is achieved through the gas shared chamber, which can also improve the performance and charge and discharge cycle life of the large-capacity battery.

[0078] In order to facilitate the electrical connection of such large-capacity batteries, avoidance holes are opened on the second cover plate corresponding to the polarity terminals of each single cell; each single cell polarity terminal extends out of the corresponding avoidance hole as a large-capacity battery polarity terminal (all single cell polarity terminals on one side serve as the first polarity terminals of the large-capacity battery, and all single cell polarity terminals on the other side serve as the second polarity terminals of the large-capacity battery, wherein the polarities of the first polarity terminal and the second polarity terminal are opposite), and the second cover plate area corresponding to the avoidance hole is fixedly sealed with the single cell housing, so that the avoidance hole portion of the second cover plate is sealed.

[0079] When the sizes of the individual cells in the z direction are similar, the avoidance hole can be sealed by directly welding the second cover plate area around the avoidance hole to the upper cover plate of the corresponding individual cell;

[0080] When the dimensions of each single cell in the z direction have a large deviation, if it is necessary to ensure that the lower cover plates of each single cell are in the same horizontal plane, the upper cover plates of each single cell will have uneven heights, resulting in gaps between the upper cover plates and the second cover plates of some individual single cells, which may lead to cold welds between the second cover plate and the upper cover plate during welding, or even the problem of being unable to weld. In order to solve this problem, a sealing connector can be used to achieve sealing of the avoidance hole.

[0081] The specific sealing connector may include a hollow member (similar to a hollow tube), which is sleeved on the outside of the polarity terminal of the single cell; the bottom of the hollow member is sealed to the area around the polarity terminal of the upper cover plate of the single cell, and the top of the hollow member is sealed to the second cover plate area corresponding to the avoidance hole. The sealing connection can be achieved by welding. The second cover plate area corresponding to the avoidance hole is the outer surface area of ​​the second cover plate around the avoidance hole; or it is the hole wall of the avoidance hole.

[0082] It should be noted that the single cell polarity terminal described here can be a single cell pole. In order to avoid the single cell pole being unable to smoothly extend out of the avoidance hole as a polarity terminal or the height of the extended avoidance hole does not meet the set requirements, a pole adapter can also be connected to the single cell pole, and the overall structure of the single cell pole and the pole adapter can be used as the single cell polarity terminal.

[0083] In addition, in order to improve the heat dissipation performance of such large-capacity batteries, a heat transfer tube clamping portion can be provided at the location where the polarity terminal of the single battery extends out of the avoidance hole; the heat transfer tube is fixed to the heat transfer tube clamping portion. When the temperature of the large-capacity battery is higher than the set threshold, the large-capacity battery is cooled by passing a heat transfer medium with a lower temperature into the heat transfer tube; when the temperature of the large-capacity battery is lower than the set threshold, the large-capacity battery is heated by passing a heat transfer medium with a higher temperature into the heat transfer tube; by controlling the temperature of the heat transfer medium, it can be ensured that the large-capacity battery always operates at a normal operating temperature.

[0084] In order to lead the thermal runaway smoke out of the large-capacity battery casing, an explosion relief mechanism connected to the inner cavity of the casing is provided on the casing; usually, the explosion relief mechanism directly penetrates the above-mentioned electrolyte shared chamber or gas chamber.

[0085] When the above-mentioned large-capacity batteries are assembled into energy storage devices, when individual single cells in any large-capacity battery experience thermal runaway, the single cells will deform in the x and y directions, causing cracks in the weld between the upper cover plate and the cylinder of the single cells. The thermal runaway smoke will leak from the cracks and diffuse into the large-capacity battery casing, increasing the pressure in the inner cavity of the casing, which can easily cause tearing of the weld between the casing and the first cover plate and the second cover plate, as well as the second cover plate area around the avoidance hole. In severe cases, the large-capacity battery or even the energy storage device may explode.

[0086] Based on the above problems, the utility model adds a first clamping plate and a second clamping plate in the outer shell, and the first clamping plate cooperates with the first side plate of the box body to apply a clamping force to each single cell in the y direction, and the second clamping plate cooperates with the second side plate of the box body to apply a clamping force to each single cell in the x direction. Ultimately, the single cells in such large-capacity batteries are constrained in three directions: x, y, and z (in the z direction, the sealing connector cooperates with the second cover plate and the first cover plate to support each single cell), ensuring that the thermal runaway smoke can be smoothly released from the explosion relief mechanism, reducing or even avoiding the problem of tearing of the single cell shell when the single cell is in thermal runaway, resulting in aggravated thermal runaway and spread of smoke.

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

[0088] Example 1

[0089] like Figure 2 , which is a schematic diagram of the exploded structure of the large-capacity battery of this embodiment, includes a housing 1 and a plurality of single cells 2 arranged in the housing 1 along the x direction.

[0090] The single cells 2 in this embodiment are square shell cells, and the number is 9. The inner cavity of each single cell 2 includes an electrolyte area and a gas area. In other embodiments, the number and shape of the single cells 2 can be adjusted according to actual needs.

[0091] from Figure 2 As can be seen from the figure, the housing 1 of this embodiment includes a box body 11 with open top and bottom, and a second cover plate 12 and a first cover plate 13 covering the top open end and the bottom open end of the box body 11 respectively.

[0092] A liquid channel extending along the x direction is provided on the first cover plate 13 as an electrolyte sharing chamber 7, the inner cavity of the electrolyte sharing chamber 7 is connected with the inner cavity electrolyte area of ​​each single battery 2;

[0093] The second cover plate 12 is provided with a gas channel extending in the x direction, serving as a gas chamber 8, the inner cavity of the gas chamber 8 and the inner cavity gas area of ​​each single battery 2 are connected;

[0094] In other embodiments, only the electrolyte sharing chamber 7 may be provided.

[0095] The second cover plate 12 is provided with a relief hole 4 through which the polarity terminals of each single battery 2 can be extended; Figure 3 and Figure 4As shown, in this embodiment, the polarity terminal of the single battery 2 is an integral structure of the single battery 2 pole 21 and the pole adapter 22. Each single battery 2 polarity terminal extends out of the corresponding avoidance hole 4, and a sealing connector 6 is added between the avoidance hole 4 and the polarity terminal. The sealing connector 6 includes a hollow member 181 (see Figure 8 ); the bottom of the hollow member 181 is sealed and connected to the first area of ​​the single cell 2, and the top of the hollow member 181 is sealed and connected to the second area of ​​the second cover plate 12; wherein the first area is the area around any polarity terminal on the upper cover plate of the single cell 2; wherein the area around the polarity terminal is the area around the insulating seal on the polarity terminal. The insulating seal is a part on the single cell 2 used to insulate the polarity terminal from the upper cover plate of the single cell 2. The second area is the area of ​​the second cover plate 12 corresponding to the avoidance hole 4 on the second cover plate 12. The area of ​​the second cover plate 12 corresponding to the avoidance hole 4 is the peripheral area on the outer surface of the second cover plate 12 corresponding to any avoidance hole 4; or the area of ​​the second cover plate 12 corresponding to the avoidance hole 4 is the hole wall of the avoidance hole 4.

[0096] Combination Figures 2 to 4 It can be seen that in this embodiment, a flat first clamping plate 31 is provided between the two first side plates of the box body 11 and the two first side walls of all the single cells 2, and the two surfaces of the first clamping plate 31 are respectively in close contact with the first side plate of the box body 11 and the first side wall of each single cell 2; wherein the first side plate of the box body 11 and the first side wall of the single cell 2 are both parallel to the xz plane. A flat second clamping plate 32 is provided between the two second side plates of the box body 11 and the second side walls of the two outermost single cells 2, and the two surfaces of the second clamping plate 32 are respectively in close contact with the second side plate of the box body 11 and the second side wall of the single cell 2; wherein the second side plate of the box body 11 and the second side wall of the single cell 2 are both parallel to the xz plane.

[0097] In some other embodiments, the first clamping plate 31 may be provided only between one of the first side plates of the box body 11 and one of the first side walls of all the single cells 2 opposite thereto. In this case, the two surfaces of the first clamping plate 31 are also closely attached to the first side plate of the box body 11 and the first side walls of each single cell 2 respectively; the other first side wall of all the single cells 2 is closely attached to the other first side plate of the box body 11, and based on the cooperation between the first clamping plate 31 and the two first side plates of the box body 11, all the single cells 2 can also be clamped in the y direction. However, relative to this embodiment, when the gap between the first side wall of the single cell 2 and the first side plate of the box body 11 is large, inserting the first clamping plate 31 into the gap will cause a large offset between the center of the single cell 2 and the center of the second cover plate in the y direction, which may cause the polarity terminals of each single cell 2 to be unable to extend out of the corresponding avoidance hole 4.

[0098] Similarly, in some other embodiments, the second clamping plate 32 may be provided only between one of the second side plates of the box body 11 and the second side wall of the outermost single battery 2 opposite thereto. In this case, the second side wall of the other outermost single battery 2 is in close contact with the other second side plate of the box body 11. Based on the cooperation between the second clamping plate 32 and the two second side plates of the box body 11, all single batteries 2 may be clamped in the x direction. However, relative to this embodiment, when the gap between the second side wall of the single battery 2 and the second side plate of the box body 11 is large, inserting the second clamping plate 32 into the gap will cause a large offset between the center of the single battery 2 and the center of the second cover plate in the x direction, which may result in the polarity terminals of each single battery 2 being unable to extend out of the corresponding avoidance hole 4.

[0099] In order to balance the force on the first side wall and the second side wall of the single cell 2, in this embodiment, preferably, in the z direction, the sizes of the first clamping plate 31 and the second clamping plate 32 are respectively similar to the first side wall and the second side wall of the single cell 2, and the two can be completely equal.

[0100] To facilitate installation of the first clamping plate 31, the size of the first clamping plate 31 is slightly smaller than the size of the first side plate of the box body 11 in the x direction; to facilitate installation of the second clamping plate 32, the size of the second clamping plate 32 is slightly smaller than the size of the second side plate of the box body 11 in the y direction.

[0101] Since the first clamping plate 31 and the second clamping plate 32 are both placed in the inner cavity of the outer shell 1, the first clamping plate 31 and the second clamping plate 32 should be made of a material that does not react with the electrolyte; in addition, the first clamping plate 31 and the second clamping plate 32 should have a certain rigidity so as to facilitate their insertion into the gap between the single battery 2 and the box body 11.

[0102] In this embodiment, each single battery 2 can be clamped in three directions: x, y, and z through the following process:

[0103] First, from the open end at the top of the box body 11, arrange the individual single cells 2 in the box body 11 with the first cover plate 13 sealed at the bottom; after they are in place, insert the first clamping plate 31 into the gap between the first side wall of the single cell 2 and the first side plate of the box body 11, and clamp all the single cells 2 in the y direction; insert the second clamping plate 32 into the gap between the second side wall of the single cell 2 and the second side plate of the box body 11, and clamp all the single cells 2 in the x direction; fix the second cover plate 12 to the open end at the top of the box body 11, and use the sealing connector 6 to fix and seal the second cover plate 12 area corresponding to the avoidance hole 4 to the shell of the single cell 2, and clamp all the single cells 2 in the z direction.

[0104] This embodiment clamps each single cell 2 in the x, y, and z directions to ensure that the thermal runaway smoke can be smoothly released from the explosion relief mechanism, reducing or even avoiding the problem of the thermal runaway aggravated and smoke spreading caused by the tearing of the shell of the single cell 2 when the single cell 2 is in thermal runaway.

[0105] Example 2

[0106] like Figure 5 As shown, it is an exploded schematic diagram of the large-capacity battery of this embodiment; it can be seen from the figure that, unlike Example 1, one of the first clamping plates 31 of this embodiment includes multiple first sub-clamping plates 311, and the other first clamping plate 31 is the same as Example 1, which is an integrated flat plate structure with a dimension in the x direction slightly smaller than the dimension of the box body 11.

[0107] Each first sub-clamping plate 311 in this embodiment corresponds to a single cell 2 one by one, and is arranged between the first side wall of each single cell and the first side plate of the box body 11, and the size of each first sub-clamping plate 311 in the x direction is equal to the size of the first side wall of the single cell 2.

[0108] Compared with Example 1, when the size deviation of each single cell 2 in the y direction is large, this embodiment can select first sub-clamping plates 311 of different thicknesses according to the distance between the first side plate of the single cell 2 and the first side wall of the box body 11, so as to ensure that all single cells 2 are clamped in the y direction.

[0109] In some other embodiments, the two first clamping plates 31 can be set as a split structure, that is, the two first clamping plates 31 are composed of multiple first sub-clamping plates 311; each of the two first side walls of each single battery 2 corresponds to a first sub-clamping plate 311; however, compared with this embodiment, its structure is more complicated and the subsequent installation is also more complicated.

[0110] Example 3

[0111] like Figure 6 As shown, it is a schematic diagram of the local structure of the large-capacity battery of this embodiment. It can be seen from the figure that, different from the above-mentioned embodiment, this embodiment is provided with a plurality of partitions 5 in the inner cavity of the box body 11, and the plurality of partitions 5 are arranged at equal intervals along the x direction, dividing the inner cavity of the box body 11 into a plurality of single cell battery 2 mounting cavities; a single cell battery 2 is fixed in each single cell battery 2 mounting cavity.

[0112] To facilitate the installation of the single cell 2, the size of the installation cavity of each single cell 2 needs to be slightly larger than the thickness and width of the single cell 2 in the x and y directions. Similarly, when the assembly is completed, there is a gap between each single cell 2 and the wall of the single cell installation cavity (including the partition and the first side plate of the box body). The single cell is deformed in the x and y directions, resulting in cracks between the upper cover and the cylinder. Thermal runaway smoke will leak from the cracks in the single cell and spread to the entire energy storage device box.

[0113] Therefore, from Figure 6 It can be seen that in this embodiment, two first sub-clamping plates 311 and two second clamping plates 32 are fixed in each single cell 2 installation cavity. The two first sub-clamping plates 311 are respectively located between the two first side walls of the single cell 2 and the corresponding first side plate of the box body 11. In the single cell 2 installation cavity near the middle part, the two second clamping plates 32 are respectively located between the two second side walls of the single cell 2 and the corresponding partition plate 5. In the single cell 2 installation cavity located at the outermost part, the two second clamping plates 32 are respectively located between the second side wall of the single cell 2 and the corresponding partition plate 5 and the second side plate of the box body 11.

[0114] In this embodiment, each single battery 2 can be clamped in three directions: x, y, and z through the following process:

[0115] First, from the open end of the top of the box body 11, arrange each single battery 2 in each single battery 2 installation cavity sealed with the first cover plate 13 at the bottom; Figure 7 As shown, each first sub-clamping plate 311 is inserted into the gap between the first side wall of the single cell 2 and the first side plate of the box body 11, and all the single cells 2 are clamped in the y direction; the second clamping plate 32 is inserted into the gap between the second side wall of the single cell 2 and the partition 5 and the second side plate of the box body 11, and all the single cells 2 are clamped in the x direction; the second cover plate 12 is fixed to the open end of the top of the box body 11, and the second cover plate 12 area corresponding to the avoidance hole 4 is fixedly sealed to the shell of the single cell 2 by using the sealing connector 6, and all the single cells 2 are clamped in the z direction.

[0116] In this embodiment, the heat generated during the charging and discharging process of each single battery can be transmitted to the outside through the partition and the second clamping plate, thereby reducing the risk of thermal runaway; in addition, the partition can also enhance the strength of the box.

[0117] Example 4

[0118] Different from the above-mentioned embodiment, the present embodiment optimizes the structure of the sealing connector 6 to further improve the sealing performance of the avoidance hole 4 .

[0119] When the sealing connector 6 in Example 1 is used to achieve fixed sealing between the second cover plate 12 area corresponding to the avoidance hole 4 and the housing of the single battery 2, the following problems are found in actual processing and application:

[0120] 1. When the bottom of the hollow member 181 and the area around the polarity terminals of the upper cover of the single battery 2 are sealed and connected by welding, part of the upper cover of the single battery 2 is easily damaged, resulting in the single battery 2 being scrapped;

[0121] 2. The area around the polarity terminals of some single-cell battery 2 upper cover plates may not be welded due to the presence of other structures;

[0122] 3. Even if there is no visible damage during the processing, in actual application, when thermal runaway occurs in individual single cells 2 of the large-capacity battery with the above-mentioned sealing connector 6, the thermal runaway smoke will leak from the connection area around the polarity terminal of the upper cover plate of the single cell 2. Therefore, if the above-mentioned multiple large-capacity batteries are used to assemble energy storage equipment, when thermal runaway occurs, the thermal runaway smoke may leak from the welding parts around the polarity terminal of the upper cover plate of the single cell 2 and diffuse, posing certain safety hazards. Based on this problem, the large-capacity battery after thermal runaway was disassembled, and it was found that cracks appeared in the connection area around the polarity terminal of the upper cover plate of the single cell 2 that experienced thermal runaway (the connection area with the bottom of the sealing connector 6). After analysis, the reason for this phenomenon is that there is a certain weak area around the polarity terminal of the upper cover plate of the single cell 2. If the connection area falls into this weak area, it will cause the above-mentioned problem. The reason is that the welding process causes certain damage to the weak area, which makes the area unable to withstand the thermal runaway pressure. When thermal runaway occurs, cracks are generated, causing thermal runaway smoke to leak from the area.

[0123] Based on this, the present embodiment considers optimizing the structure of the sealing connector 6, mainly adjusting the size and shape of the bottom open end 1811 of the hollow component 181, so that the orthographic projection of the bottom open end 1811 of the hollow component 181 on the upper cover of the single cell 2 covers the weak area around the polarity terminal of the upper cover of the single cell 2; thereby ensuring that when welding the bottom of the hollow component 181 and the surrounding area of ​​the polarity terminal of the upper cover of the single cell 2, the weak area around the polarity terminal of the upper cover of the single cell 2 can be avoided, thereby avoiding damage to the weak area during the welding process.

[0124] It should be noted that:

[0125] 1. The size, position and shape of the weak area corresponding to the single battery 2 produced by different manufacturers are also different. Therefore, when processing the sealing connector 6, this embodiment first needs to determine the size, position and shape of the weak area of ​​the single battery 2, and adjust the size and shape of the bottom open end 1811 of the hollow component 181 according to the single battery 2 produced by different manufacturers.

[0126] 2. In this embodiment, areas that are easily damaged by welding, areas that cannot be welded, or areas where the pressure bearing capacity is reduced due to welding are all referred to as weak areas.

[0127] like Figure 8 , which is a schematic structural diagram of the sealing connector 6 of this embodiment. It can be seen from the figure that the sealing connector 6 of this embodiment includes a hollow component 181, which can also be called a hollow pipe.

[0128] Both ends of the hollow component 181 are open ends. For the convenience of description, one of the open ends is defined as a bottom open end 1811 , and the other open end is defined as a top open end 1812 .

[0129] The bottom of the hollow member 181 is used to seal and connect with the first area of ​​the single cell 2, and the first area mentioned here is the peripheral area of ​​the weak area of ​​the upper cover of the single cell 2; in order to seal and connect the bottom of the hollow member 181 with the first area of ​​the single cell 2, the orthographic projection (orthographic projection area) of the bottom open end 1811 of the hollow member 181 on the upper cover of the single cell 2 covers the weak area around the polarity terminal on the upper cover of the single cell 2 in this embodiment. It should be noted that in this case, the orthographic projection (orthographic projection area) of the bottom open end 1811 of the hollow member 181 on the upper cover of the single cell 2 must cover the polarity terminal on the upper cover of the single cell 2.

[0130] During welding, the hollow member 181 can be positioned on the upper cover of the single cell 2, and the position of the hollow member 181 can be adjusted so that the orthographic projection of the open end 1811 of the bottom of the hollow member 181 on the upper cover of the single cell 2 covers the weak area around the polarity terminal on the upper cover of the single cell 2; then, the bottom of the hollow member 181 and the upper cover of the single cell 2 are welded. Since the two welded surfaces are perpendicular to each other, the reliability and sealing of the welded part may be relatively weak.

[0131] To solve this problem, Fig. 9 and Fig.10 As shown, the bottom plate 182 can be fixed to the open end 1811 at the bottom of the hollow member 181, and a third through hole 1820 can be opened on the bottom plate 182. The size of the third through hole 1820 needs to ensure that the polarity terminal of the single battery 2 can pass through. The bottom plate 182 is welded to the outer area of ​​the weak area around the polarity terminal of the upper cover plate of the single battery 2. Figure 3 and Figure 4 .

[0132] The size and shape of the third through hole 1820 can be determined according to the size and shape of the weak area of ​​the single cell 2. As can be seen from the figure, the third through hole 1820 of this embodiment is a waist-shaped first through hole, and the weak area of ​​the corresponding single cell 2 is also a waist-shaped area; preferably, the orthographic projection of the third through hole 1820 on the upper cover of the single cell 2 covers the weak area around the polarity terminal on the upper cover of the single cell 2; in this way, when the bottom plate 182 is welded to the upper cover of the single cell 2, the welding part must be located outside the weak area.

[0133] The bottom plate 182 can be fixed to the bottom open end 1811 of the hollow component 181 by welding, or the bottom plate 182 and the hollow component 181 can be processed into an integral part by an integrated processing method. Compared with separate parts, the processing cost of the integral part is lower, and it also has higher structural stability.

[0134] In some other embodiments, such as Fig.11 As shown, a second annular plate 183 can also be fixedly sleeved on the outer side of the bottom of the hollow member 181, and the second annular plate 183 is welded to the peripheral area of ​​the weak area around the polarity terminal on the upper cover of the single cell 2. Because the orthographic projection of the open end 1811 at the bottom of the hollow member 181 on the upper cover of the single cell 2 covers the weak area around the polarity terminal on the upper cover of the single cell 2, the second annular plate 183 is located on the outer side of the bottom of the hollow member 181, and its inner diameter must be larger than the diameter of the open end 1811 at the bottom of the hollow member 181. In this way, when the second annular plate 183 is welded to the upper cover of the single cell 2, the welding part must be located in the peripheral area of ​​the weak area. The second annular plate 183 can be fixed to the open end 1811 at the bottom of the hollow member 181 by welding, or the second annular plate 183 and the hollow member 181 can be processed into an integral part by an integrated processing method. Compared with the split part, the processing cost of the integral part is lower, and it also has higher structural stability.

[0135] Combination Figure 3 and Figure 4 , the top of the hollow member 181 is sealed and connected to the second cover plate 12 area around the avoidance hole 4; in this embodiment, the size and shape of the open end 1812 at the top of the hollow member 181 are mainly related to the shape of the avoidance hole 4. For example, the avoidance hole 4 of the large-capacity battery adapted by the hollow member 181 in this embodiment is a round hole, so the open end 1812 at the top of the hollow member 181 is round, and the diameter is slightly smaller than the diameter of the avoidance hole 4. In this embodiment, the outer peripheral surface of the hollow member 181 is used to fit tightly with the hole wall of the avoidance hole 4, and the hollow member 181 and the avoidance hole 4 are welded and sealed by laser welding; the welding area between the hollow member 181 and the avoidance hole 4 is between the outer edge of the top of the hollow member 181 and the inner edge of the hole wall of the avoidance hole 4.

[0136] In some other embodiments, such as Fig.12 As shown (different from Fig. 9 , the third through hole 1820 on the bottom plate 182 of the sealing connector 6 is a circular hole), and a first annular plate 184 can be fixedly sleeved on the outer side of the top of the hollow member 181, and the first annular plate 184 is welded and sealed with the second area of ​​the housing 1; the second area is the outer surface area of ​​the second cover plate 12 around the avoidance hole 4. The first annular plate 184 can be fixed to the open end 1812 of the top of the hollow member 181 by welding.

Claims

1. A large capacity battery, characterized in that: It comprises a housing, at least one first clamping plate, at least one second clamping plate and n single cells located in the housing; Wherein n is an integer greater than 1; n single cells are arranged in the same direction in the inner cavity of the housing; the inner cavity of each single cell includes an electrolyte area and a gas area; The housing comprises a box body, a first cover plate and a second cover plate; The bottom and top of the box are open; An electrolyte sharing chamber is provided on the first cover plate, and the first cover plate covers the open end of the bottom of the box body and is sealed and connected to the open end; the inner cavity of the electrolyte sharing chamber is connected to the electrolyte area of ​​the inner cavity of each single battery; The second cover plate is provided with avoidance holes for allowing the polarity terminals of each single battery to extend out; The second cover plate covers the open end of the top of the box body and is sealed and connected to the open end; the polarity terminals of each single battery extend out of the avoidance hole, and the second cover plate area corresponding to the avoidance hole is fixedly sealed with the single battery housing; The first clamping plate is disposed between the first side plate of the box body and the first side wall of each single cell, and the two surfaces of the first clamping plate are respectively in close contact with the first side plate of the box body and the first side wall of each single cell, wherein the first side plate of the box body and the first side wall of each single cell are parallel to the xz plane; The second clamping plate is arranged between the second side plate of the box body and the second side wall of the outermost single cell, and the two surfaces of the second clamping plate are respectively in close contact with the second side plate of the box body and the second side wall of the outermost single cell, wherein the second side plate of the box body and the second side wall of the single cell are both parallel to the yz plane.

2. The large-capacity battery according to claim 1, characterized in that: There are two first clamping plates, and the two first clamping plates are respectively located between the two first side plates of the box body and the first side walls of each single battery cell opposite thereto.

3. The large-capacity battery according to claim 2, characterized in that: One of the first clamping plates includes n first sub-clamping plates, each of which corresponds to a single cell one by one, and in the x direction, the size of each first sub-clamping plate is equal to the size of the first side wall of the single cell; the other first clamping plate is a whole flat plate.

4. The large-capacity battery according to claim 2, characterized in that: In the z direction, the size of the first clamping plate is equal to the size of the first side wall of the single battery.

5. The large-capacity battery according to claim 1, characterized in that: There are two second clamping plates, and the two second clamping plates are respectively located between the second side walls of the two outermost single cells and the second side plates of the box body opposite thereto.

6. The large-capacity battery according to claim 1, characterized in that: The box body also includes a plurality of partitions arranged in the inner cavity of the box body, dividing the inner cavity of the box body into a plurality of single-cell battery installation cavities; a single-cell battery is fixed in each single-cell battery installation cavity; The first clamping plate includes at least n first sub-clamping plates, and the n first sub-clamping plates correspond to the n single cells one by one; a first sub-clamping plate is arranged between the first side wall of each single cell and the first side plate of the box body; There are at least n second clamping plates, and a second clamping plate is arranged between at least one second side wall of each single battery and a corresponding partition plate.

7. The large-capacity battery according to claim 6, characterized in that: There are 2n first sub-clamping plates, and one first sub-clamping plate is arranged between the two first side walls of each single battery and the corresponding first side plate of the box body.

8. The large-capacity battery according to claim 6, characterized in that: There are 2n second clamping plates, and a second clamping plate is provided between the two second side walls of each single battery and the corresponding partition plate and the second side plate of the box body.

9. The large capacity battery according to any one of claims 1 to 8, characterized in that: It also includes 2n sealing connectors; the second cover plate area corresponding to each avoidance hole is fixedly sealed with the single cell housing through a sealing connector; the sealing connector includes a hollow component sleeved on the outside of the polarity terminal of the single cell, and the orthographic projection of the open end of the bottom of the hollow component on the upper cover plate of the single cell covers the weak area around the polarity terminal on the upper cover plate of the single cell; The bottom of the hollow component and the peripheral area of ​​the weak area are welded and sealed, and the top of the hollow component and the second cover plate area corresponding to the avoidance hole are welded and sealed.

10. The large-capacity battery according to claim 9, characterized in that: The sealing connector also includes a bottom plate fixed to the open end of the bottom of the hollow component; a third through hole is opened on the bottom plate; the third through hole covers the weak area around the polarity terminal on the upper cover plate of the single cell through its positive projection on the upper cover plate of the single cell; the bottom plate is used for welding and sealing with the peripheral area of ​​the weak area.

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