High-capacity battery

Abstract

The utility model belongs to the field of batteries, and particularly relates to a high-capacity battery. The high-capacity battery comprises a shell, at least one clamping plate positioned in the shell and n single batteries, the n single batteries are arranged in the shell along the x direction; the shell is provided with at least one shared cavity extending in the x direction. Avoiding holes corresponding to polar terminals of the single batteries are formed in the top plate of the shell; each single battery polarity terminal extends out of the corresponding avoiding hole, and the shell top plate area corresponding to the avoiding hole is fixedly sealed with the single battery shell; the clamping plate is arranged between the shell side plate and the second side wall of each single battery, and the two surfaces of the clamping plate are respectively clung to the shell side plate and the second side wall of each single battery, so that the problems that the single batteries deform in the y direction, cracks occur between the upper cover plate and the second side walls, and smoke spreads from the cracks can be avoided.

Description

Technical Field

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

[0002] At present, in the market, multiple single cells are connected in parallel, in series or in series-parallel to form a large-capacity battery (which can also be called a battery module or a battery pack).

[0003] However, there are differences among the single cells in the existing large-capacity batteries. Due to the existence of the cask effect, the large-capacity battery is often affected by the single cell with the worst performance, resulting in great limitations on the capacity upper limit and cycle times of the entire large-capacity battery. Therefore, how to improve the uniformity of each single cell in the large-capacity battery has become the focus and difficulty in the research of this field.

[0004] To solve the above problems, Chinese Patent CN220797038U discloses a large-capacity battery, and its structure is as Figure 1 shown. Such a large-capacity battery includes a housing and multiple single cells;

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

[0006] Multiple single cells are connected in parallel in sequence and arranged in the inner cavity of the housing along the x direction; inside the housing, the first side walls of each single cell are parallel to each other and parallel to the yz plane.

[0007] The bottom plate of the housing is provided with an electrolyte sharing chamber, and the electrolyte sharing chamber is communicated with the electrolyte area in the inner cavity of each single cell; the electrolytes in the inner cavities of each single cell are communicated through the 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, improving the consistency between each single cell to a certain extent, and thus improving the cycle life of the large-capacity battery to a certain extent.

[0008] Avoidance holes are opened on the top plate of the housing to enable the polar terminals of each single cell to extend out; the polar terminals of each single cell extend out of the avoidance holes, and the area of the top plate of the housing corresponding to the avoidance holes is fixedly sealed with the upper cover plate of the single cell.

[0009] It should be noted that the above-mentioned polar terminal of the single cell can be the pole column of the single cell. If it is necessary to avoid that the pole column of the single cell cannot smoothly extend out of the avoidance hole or the height of extending out of the avoidance hole does not meet the set requirements, a pole column adapter can also be connected to the pole column of the single cell, and the overall structure formed by matching the pole column of the single cell and the pole column adapter is used as the polar terminal of the single cell.

[0010] In addition, a gas chamber is also provided on the top plate of the housing, and the above gas chamber covers the gas ports on the top of each single cell.

[0011] It should be noted that the gas port here has the following two meanings:

[0012] 1) The gas port is a through hole directly opened on the upper cover plate of the single battery and penetrating the inner cavity of the single battery;

[0013] At this time, the inner cavity of the gas chamber is connected to the gas areas of the inner cavities of each single battery through the gas port. Based on the gas chamber, the gas areas of each single battery can be connected to achieve gas balance, enabling the gas sharing of each single battery to ensure the consistency of each single battery, and improving the cycle life of the large-capacity battery to a certain extent; when thermal runaway occurs in any single battery, the flue gas in the inner cavity of the single battery enters the gas chamber and is discharged through the gas chamber, improving the safety of the large-capacity battery.

[0014] 2) The gas port is a venting port or explosion-proof port provided on the upper cover plate of the single battery, and a venting film is provided at the venting port or explosion-proof port;

[0015] At this time, the gas chamber is used as a venting channel. When the venting film at the gas port of any single battery is broken by the flue gas in the inner cavity, the inner cavity of the single battery is connected to the gas chamber, and the internal flue gas is discharged through the gas chamber, improving the safety of the large-capacity battery.

[0016] When multiple large-capacity batteries are assembled into an energy storage device, usually the venting mechanisms of each large-capacity battery (the venting mechanism is a pipe section fixed on the outer shell and communicating with the inner cavity of the outer shell, and a venting film is fixed in the pipe section) are connected to a venting manifold pipe, and the outlet end of the venting manifold pipe is led out of the energy storage device box body. When thermal runaway occurs in any single battery inside the large-capacity battery, the thermal runaway flue gas is discharged from the energy storage device box body through the gas port of the single battery, the venting mechanism, and the venting manifold pipe in sequence, avoiding the safety accident caused by the thermal runaway flue gas diffusing throughout the energy storage device box body after thermal runaway.

[0017] However, through experimental verification, when thermal runaway occurs in individual single batteries in the above large-capacity batteries, the thermal runaway flue gas will leak from the weld between the upper cover plate of the single battery and the second side wall of the single battery (where the second side wall is the side wall parallel to the xz plane). Therefore, if the above multiple large-capacity batteries are assembled into an energy storage device, after thermal runaway occurs, the thermal runaway flue gas will not only enter the venting manifold pipe through the venting mechanism and be discharged, but may also leak from the weld between the upper cover plate of the single battery and the second side wall, and diffuse into the entire inner cavity of the outer shell of the large-capacity battery, increasing the pressure in the inner cavity of the outer shell, easily causing the tearing of the weak area of the outer shell, and seriously may cause the explosion of the large-capacity battery or even the energy storage device. Summary of the Invention

[0018] The object of the present utility model is to provide a large-capacity battery, which overcomes the safety problem caused by the leakage of the thermal runaway flue gas from between the upper cover plate of the single battery and the second side wall, resulting in the diffusion of the thermal runaway flue gas.

[0019] The concept of the present utility model is as follows:

[0020] Based on the problems existing in the background technology, the above large-capacity battery after thermal runaway is disassembled, and it is found that there is a crack between the upper cover plate of the single battery with thermal runaway and its second side wall. After analysis, the reason for this phenomenon is that:

[0021] The outer shell of the above large-capacity battery includes a cylinder with open ends at both ends and end plates respectively fixed at the two open ends of the cylinder; during the assembly process of the large-capacity battery, after the single battery is pushed into the cylinder, the end plates are then fixed at the open ends of the cylinder;

[0022] In order to facilitate the pushing of each single battery into the cylinder, in the y direction, the size of the cylinder needs to be slightly larger than the size of the single battery; after assembly, there is a certain gap between the second side wall of the single battery and the outer shell side plate (the outer shell side plate is the side plate of the outer shell parallel to the xz plane). Due to the existence of this gap, when thermal runaway occurs, the binding force of the single battery in the y direction is small, and under the internal pressure, it is easy to deform, which in turn causes the upper cover plate and the second side wall of the single battery to tear, and further causes the thermal runaway flue gas to leak from the torn part.

[0023] In addition, during the assembly process of the above large-capacity battery, when fixing the end plates at both ends to the open ends of the cylinder, the outermost single battery needs to be pressed tightly. Therefore, in the x direction, based on the fact that the end plates at both ends can apply a clamping force to each single battery, when thermal runaway occurs, the problem that the single battery deforms in the x direction and tears the connection part between the upper cover plate and its first side wall can be avoided;

[0024] At the same time, a sealing connector can be added between the avoidance hole and the polarity terminal of the above large-capacity battery to realize the fixed sealing of the outer shell top plate area corresponding to the avoidance hole and the single battery housing; such a sealing connector includes a hollow member; the hollow member is sleeved outside the single battery polarity terminal, the bottom of the hollow member is hermetically connected to the upper cover plate area around the single battery polarity terminal, and the top of the hollow member is hermetically connected to the outer shell top 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 outer shell top plate and the outer shell bottom plate, and can also apply a clamping force to each single battery; when thermal runaway occurs, the problem that the single battery deforms in the z direction and a crack appears between the upper cover plate and the cylinder can be avoided;

[0025] In summary, for the above large-capacity battery, in the x direction, clamping forces can be applied to each single battery based on the two end plates; in the z direction, the sealing connection member cooperates with the top and bottom plates of the housing to hold each single battery; when thermal runaway occurs, it can prevent the single battery from deforming in the x and z directions due to internal pressure, which may cause cracks between the upper cover plate and the cylinder body. However, in the y direction, since there is a gap between the second side wall of the single battery and the side wall of the housing, when thermal runaway occurs, the single battery is prone to deform in the y direction, which may further lead to cracks between the upper cover plate and the cylinder body, causing the leakage of thermal runaway flue gas from the cracks.

[0026] Based on the above analysis, for the present utility model, only by applying clamping forces to each single battery in the y direction, the single batteries in the large-capacity battery can be restricted in all three directions of x, y, and z, ensuring that the thermal runaway flue gas can be smoothly released from the explosion venting mechanism, reducing or even avoiding the problem of the single battery casing being torn during thermal runaway of the single battery, which may cause the intensification of thermal runaway and the spread of flue gas.

[0027] Therefore, the present utility model proposes the following technical solution:

[0028] A large-capacity battery, characterized in that it includes a housing, at least one clamping plate located inside the housing, and n single batteries; the n single batteries are arranged in the housing along the x direction; where n is an integer greater than 1;

[0029] The housing is provided with at least one shared chamber extending along the x direction;

[0030] Avoidance holes are provided on the top plate of the housing corresponding to the polarity terminals of each single battery; the polarity terminals of each single battery extend out of the corresponding avoidance holes, and the area of the top plate of the housing corresponding to the avoidance holes is fixedly sealed with the casing of the single battery.

[0031] The clamping plate is arranged between the side wall of the housing and the second side wall of each single battery, and the two surfaces of the clamping plate are respectively in close contact with the side wall of the housing and the second side wall of each single battery; where the side wall of the housing and the second side wall of the single battery are both parallel to the xz plane.

[0032] In the present utility model, by providing a clamping plate in the housing of the large-capacity battery, in the y direction, the clamping plate cooperates with the two side walls of the housing to clamp each single battery. When thermal runaway occurs, due to the clamping action of the clamping plate, it can prevent the single battery from deforming in the y direction, and the problem of cracks appearing between the upper cover plate and the second side wall, resulting in the spread of flue gas from the cracks can be avoided.

[0033] Further, there are two clamping plates, one clamping plate is arranged between one side wall of the housing and one second side wall of each single battery, and the other clamping plate is arranged between the other side wall of the housing and the other second side wall of each single battery.

[0034] Further, in the z direction, the size of the clamping plate is equal to the size of the second side wall of the single cell.

[0035] Further, the shared chamber is an electrolyte shared chamber;

[0036] The housing includes a cylindrical component with both ends open and end plate components covering the two open ends of the cylindrical component;

[0037] A liquid channel extending in the x direction is provided at the bottom of the cylindrical component as the electrolyte shared chamber, and the inner cavity of the electrolyte shared chamber is communicated with the inner cavities of all single cells.

[0038] Further, the cylindrical component includes a cylinder and two bosses provided on the inner bottom surface of the cylinder, extending in the x direction and arranged in the y direction with the same length as the cylinder. The top surface of the bosses is the supporting surface of each single cell. In the y direction, a liquid channel is formed between the two bosses as the electrolyte shared chamber, which can be integrally formed by an aluminum extrusion process, having a lower processing cost and better structural stability.

[0039] Further, two shared chambers can be provided. One of the shared chambers is the above-mentioned electrolyte shared chamber, and the other shared chamber is a gas chamber provided on the top plate of the housing, covering the gas ports at the tops of all single cells;

[0040] The gas port is a through hole, and the inner cavity of the gas chamber is directly communicated with the gas areas of the inner cavities of all single cells through the gas port; Based on the gas chamber, the gas areas of all single cells can be communicated to achieve gas balance, enabling the gas sharing of each single cell to ensure the consistency of each single cell, and improving the cycle life of the large-capacity battery to a certain extent; When thermal runaway occurs in any single cell, the flue gas in the inner cavity of the single cell enters the gas chamber and is discharged through the gas chamber, improving the safety of the large-capacity battery.

[0041] Or, a bursting disc is provided at the gas port. When the bursting disc at the gas port of any single cell is broken by the flue gas in the inner cavity, the gas area in the inner cavity of the single cell is communicated with the inner cavity of the gas chamber. At this time, the gas chamber is used as a bursting relief channel. When the bursting disc at the gas port of any single cell is broken by the flue gas in the inner cavity, the inner cavity of the single cell is communicated with the gas chamber, and the flue gas inside is discharged through the gas chamber, improving the safety of the large-capacity battery.

[0042] Further, the end plate component includes a first end plate, a second end plate, and a third end plate;

[0043] A first through hole is provided on the first end plate; The first end plate cooperates with a bursting relief mechanism fixed at the first through hole to seal the open end of the gas chamber, the open end of the electrolyte shared chamber, and the open end of the cylinder of the large-capacity battery;

[0044] The second end plate is fixedly connected to the first end plate. The two are parallel to each other and there is a gap between them, and this gap serves as a gas channel. The gas channel extends in the z direction. The inlet end of the gas channel is used to communicate with the gas chamber, and the outlet end of the gas channel communicates with the second through hole. In the z direction, the inlet end of the gas channel is higher than the outlet end of the gas channel.

[0045] Two surfaces of the third end plate are respectively in close contact with the first side wall of the outermost single battery and the inner surface of the second end plate.

[0046] Set the fixed area of the explosion relief mechanism as the open end of the electrolyte sharing chamber with a relatively large area or the end plate area between the open end of the gas chamber and the open end of the electrolyte sharing chamber. Compared with fixing the explosion relief mechanism in the end plate area opposite to the gas chamber, the explosion relief mechanism is easier to install.

[0047] When the end plate assembly is sealed and fixed at the open end of the cylinder assembly, the first through hole is sealed by using the explosion relief mechanism. The inlet of the gas channel communicates with the gas chamber, and the outlet of the gas channel communicates with the explosion relief mechanism through the first through hole. And directly use the gap between the first end plate and the second end plate as the gas channel, so that the gas channel has a relatively large flow area, and the large-capacity battery has higher safety performance.

[0048] By adjusting the dimension of the third end plate in the x direction, in the x direction, all single batteries are clamped to avoid the problem that the single battery deforms in the x direction and tears the connection part between the upper cover plate and its first side wall. At the same time, the stability of each single battery in the inner cavity of the outer shell can be improved, preventing the problem that each single battery bulges and causes the reduction of the cycle performance of the large-capacity battery. In addition, the third end plate can isolate the gas channel from the outermost single battery, further reducing the influence of the thermal runaway flue gas in the gas channel on the outermost single battery.

[0049] Furthermore, two first support ribs are integrally arranged between the second end plate and the first end plate. Each first support rib extends in the z direction, and the two first support ribs are arranged in the y direction. A gas channel is formed among the second end plate, the first end plate and the two first support ribs. Fix the first support ribs between the first end plate and the second end plate to form a gap between the second end plate and the first end plate as the gas channel. Compared with the method using screws and gaskets, the structure of the end plate assembly is relatively simple, easy to process, low in cost, and has high structural stability.

[0050] Further, the above-mentioned large-capacity battery further includes 2n sealed connectors; the outer shell top plate area corresponding to each avoidance hole and the single-cell battery housing are fixedly sealed by one sealed connector; the sealed connector includes a hollow member sleeved outside the polar terminal of the single-cell battery, and the bottom open end of the hollow member covers the weak area around the polar terminal on the upper cover plate of the single-cell battery in the orthographic projection on the upper cover plate of the single-cell battery; the bottom of the hollow member and the outer peripheral area of the weak area are welded and sealed, and the top of the hollow member and the outer shell top plate area corresponding to the avoidance hole are welded and sealed.

[0051] During use, the hollow member is sleeved outside the polar terminal of the single-cell battery, the bottom and the outer peripheral area of the weak area are welded and sealed, and the top of the hollow member and the outer shell top plate area around the avoidance hole are welded and sealed. Whether there is a gap between the outer shell and the upper cover plate of each single-cell battery, or the gap size is different, the hollow member can seal and fix the outer shell and the upper cover plate of the single-cell battery, thus ensuring the sealing performance of the outer shell of the large-capacity battery; at the same time, by optimizing the size and shape of the bottom open end of the sealed connector, the bottom open end of the hollow member covers the weak area around the polar terminal on the upper cover plate of the single-cell battery in the orthographic projection on the upper cover plate of the single-cell battery; furthermore, it is ensured that when welding the bottom of the hollow member and the area around the polar terminal on the upper cover plate of the single-cell battery, the weak area around the polar terminal on the upper cover plate of the single-cell battery can be avoided, and a series of problems such as the scrapping of the single-cell battery and the dispersion of thermal runaway flue gas caused by damage to the weak area during the welding process can be avoided.

[0052] Further, the above-mentioned sealed connector further includes a bottom plate fixed to the bottom open end of the hollow member; a third through hole is provided on the bottom plate; the orthographic projection of the third through hole on the upper cover plate of the single-cell battery covers the weak area around the polar terminal on the upper cover plate of the single-cell battery; the bottom plate is used for welding and sealing with the outer peripheral area of the weak area. Based on the bottom plate, the welding of the upper cover plate and the sealed connector can be reliably realized, and at the same time, the orthographic projection of the third through hole on the upper cover plate of the single-cell battery covers the weak area around the polar terminal on the upper cover plate of the single-cell battery; in this way, when welding the bottom plate and the upper cover plate of the single-cell battery, the welding part must be located outside the weak area. Description of the Drawings

[0053] Figure 1 is a schematic structural diagram of the large-capacity battery in the background art;

[0054] Figure 2 is a schematic structural diagram of the large-capacity battery in Embodiment 1;

[0055] Figure 3 is a schematic partial structure diagram of the large-capacity battery in Embodiment 1 Figure 1 ;

[0056] Figure 4 is a schematic partial structure diagram of the large-capacity battery in Embodiment 1 Figure 2 ;

[0057] Figure 5 It is a cross-sectional view of the large-capacity battery in Embodiment 1;

[0058] Figure 6 It is an exploded structural schematic diagram of the outer shell in Embodiment 1;

[0059] Figure 7 It is a structural schematic diagram of the cylinder assembly in Embodiment 1;

[0060] Figure 8 It is a process diagram of the assembly of the large-capacity battery in Embodiment 1;

[0061] Figure 9 It is a structural schematic of the end plate assembly in Embodiment 2 Figure 1 ;

[0062] Figure 10 It is an exploded structural schematic diagram of the end plate assembly with a gasket;

[0063] Figure 11 It is a partial structural schematic of the end plate assembly in Embodiment 2 Figure 1 ;

[0064] Figure 12 It is a partial structural schematic of the end plate assembly in Embodiment 2 Figure 2 ;

[0065] Figure 13 It is an exploded structural schematic diagram of the end plate assembly in Embodiment 2;

[0066] Figure 14 It is a structural schematic diagram of the sealing connector in Embodiment 3;

[0067] Figure 15 It is a structural schematic of the sealing connector with a bottom plate in Embodiment 3 Figure 1 ;

[0068] Figure 16 It is a structural schematic of the sealing connector with a bottom plate in Embodiment 3 Figure 2 ;

[0069] Figure 17 It is a structural schematic diagram of the sealing connector with a second annular plate;

[0070] Figure 18 It is a partial exploded schematic diagram of the large-capacity battery in Embodiment 3;

[0071] Figure 19 It is a structural schematic diagram of the sealing connector with a first annular plate;

[0072] The reference numerals in the figure are: 13, outer shell bottom plate; 14, outer shell top plate;

[0073] 1. Housing; 11. Cylinder assembly; 1111. Cylinder top plate; 1112. Cylinder bottom plate; 1113. Cylinder side plate; 112. Boss; 113. Avoidance hole; 12. End plate assembly; 121. First end plate; 1211. First sub-end plate; 1212. Second sub-end plate; 1213. Third sub-end plate; 122. Second end plate; 123. First support rib; 124. Gas passage; 125. Gasket; 126. Third end plate; 2. Single cell; 21. Terminal; 22. Terminal adapter; 3. Electrolyte sharing chamber; 4. Gas chamber; 5. First through hole; 6. Explosion relief mechanism; 7. Clamping plate; 9. Second through hole; 18. 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. Detailed implementation manners

[0074] In order to make the above objects, features, and advantages of the present utility model more obvious and understandable, the following will describe the detailed implementation manners of the present utility model in conjunction with the accompanying drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present utility model, rather than all embodiments. Based on the embodiments in the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0075] In the following description, many specific details are set forth in order to fully understand the present utility model. However, the present utility model can also be implemented in other ways different from those described herein. Those skilled in the art can make similar generalizations without departing from the connotation of the present utility model. Therefore, the present utility model is not limited by the specific embodiments disclosed below.

[0076] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by terms such as "top, bottom", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model 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. Therefore, it cannot be understood as a limitation to the present utility model. In addition, terms such as "first, second, third, fourth, etc." are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0077] The present utility model discloses a large-capacity battery, including a housing and n single cells, where n is an integer greater than 1; the n single cells are arranged in the same direction and placed inside the housing.

[0078] A rectangular housing is usually adopted. For the convenience of description, the length direction of the housing is defined as the x - direction, the width direction of the housing is defined as the y - direction, and the height direction of the housing is defined as the z - direction.

[0079] The present utility model does not specifically limit the structure of the housing, and at least the following two structures can be adopted:

[0080] The first structure: includes a cylindrical component with open ends at both ends (i.e., the port parallel to the yz - plane is an open end) and end - plate components respectively fixed at the two open ends of the cylindrical component (i.e., the end - plate components are parallel to the yz - plane);

[0081] The second structure: includes a cylinder with open ends at the top and bottom (i.e., the port parallel to the xy - plane is an open end) and an upper cover plate and a lower cover plate respectively fixed at the open ends at the top and bottom of the cylinder (i.e., both the upper cover plate and the lower cover plate are parallel to the xy - plane);

[0082] In the following embodiments, the first structure is mainly taken as an example for introduction.

[0083] At least one shared chamber extending in the x - direction is provided in the cylindrical component.

[0084] It should be noted that:

[0085] The above - mentioned shared chamber can be an electrolyte - sharing chamber. The inner cavity of the electrolyte - sharing chamber is communicated with the inner cavities of each single - cell battery. Through the electrolyte - sharing chamber, each single - cell battery can be in a unified electrolyte environment, ensuring the uniformity of the electrolyte in each single - cell battery; improving the performance and charge - discharge cycle life of large - capacity batteries. Here, the electrolyte - sharing chamber is a liquid channel extending along the length direction of the housing between the bottom of the cylindrical component and each single - cell battery. This liquid channel can be integrally formed with the bottom plate of the cylindrical component or formed by setting support members between the lower cover plate of the single - cell battery and the bottom plate of the cylindrical component.

[0086] The above - mentioned shared chamber can also be a gas chamber provided on the top plate of the cylindrical component. The gas chamber covers the gas ports on the tops of each single - cell battery in the large - capacity battery. It should be noted that the gas ports here have the following two meanings:

[0087] 1) The gas port is a first through - hole directly opened on the upper cover plate of the single - cell battery and penetrating the inner cavity of the single - cell battery;

[0088] At this time, the inner cavity of the gas chamber is connected to the gas areas of the inner cavities of each single battery through the gas ports. The gas chamber serves as a gas sharing chamber for each single battery. Based on the gas chamber, the gas areas of each single battery can be connected to achieve gas balance, enabling the gas sharing of each single battery to ensure the consistency of each single battery, and improving the cycle life of the large-capacity battery to a certain extent; when any single battery undergoes thermal runaway, the flue gas in the inner cavity of the single battery enters the gas chamber and is discharged through the gas chamber, improving the safety of the large-capacity battery.

[0089] 2) The gas port is a burst vent or explosion-proof port provided on the upper cover plate of the single battery, and a burst diaphragm is provided at the burst vent or explosion-proof port;

[0090] At this time, the gas chamber is used as a burst vent channel. When the burst diaphragm at the gas port of any single battery is broken by the flue gas in the inner cavity, the inner cavity of the single battery is connected to the gas chamber, and the internal flue gas is discharged through the gas chamber, improving the safety of the large-capacity battery. The above-mentioned sharing chamber can also be a gas chamber. By means of the gas sharing chamber, the gas balance of each single battery can be achieved, and the performance and charge-discharge cycle life of the large-capacity battery can also be improved.

[0091] The above-mentioned sharing chamber can also be a gas-liquid sharing chamber. Through a gas-liquid sharing chamber, each single battery can be in a unified electrolyte environment and gas environment, improving the performance and charge-discharge cycle life of the large-capacity battery.

[0092] To facilitate the electrical connection of such large-capacity batteries, avoidance holes are opened on the top plate of the cylinder assembly corresponding to the polarity terminals of each single battery; the polarity terminals of each single battery extend out of the corresponding avoidance holes to serve as the polarity terminals of the large-capacity battery (the polarity terminals of all single batteries on one side serve as the first polarity terminals of the large-capacity battery, and the polarity terminals of all single batteries on the other side serve as the second polarity terminals of the large-capacity battery, where the polarities of the first polarity terminals and the second polarity terminals are opposite). The area of the top plate of the cylinder assembly corresponding to the avoidance hole is fixedly sealed with the housing of the single battery, so that the avoidance hole part of the top plate of the cylinder assembly is sealed.

[0093] When the sizes of each single battery in the z direction are similar, the area of the top plate of the cylinder assembly around the avoidance hole and the upper cover plate of the corresponding single battery can be directly welded to seal the avoidance hole part;

[0094] When there are large deviations in the sizes of each single battery in the z direction, if it is necessary to ensure that the lower cover plates of each single battery are on the same horizontal plane, there will be a problem that the upper cover plates of some individual single batteries are uneven in height, resulting in gaps between the upper cover plates of some individual single batteries and the top plate of the cylinder assembly, which may cause virtual welding or even impossible welding between the top plate of the cylinder assembly and the upper cover plate during welding; to solve this problem, a sealing connector can be used to seal the avoidance hole part.

[0095] The specific sealing connector may include a hollow member (similar to a hollow tube), and the hollow member is sleeved outside the polar terminal of the single cell; the bottom of the hollow member is sealingly connected to the area around the polar terminal of the upper cover plate of the single cell, and the top of the hollow member is sealingly connected to the area of the top plate of the cylinder assembly corresponding to the avoidance hole. The sealing connection can be achieved by welding. The area of the top plate of the cylinder assembly corresponding to the avoidance hole is the outer surface area of the top plate of the cylinder assembly around the avoidance hole; or the hole wall of the avoidance hole.

[0096] It should be noted that the polar terminal of the single cell described here can be the pole column of the single cell. If it is to avoid that the pole column of the single cell as the polar terminal cannot smoothly extend out of the avoidance hole or the height of extending out of the avoidance hole does not meet the set requirements, a pole column adapter can also be connected to the pole column of the single cell, and the overall structure formed by the cooperation of the pole column of the single cell and the pole column adapter is used as the polar terminal of the single cell.

[0097] In addition, in order to improve the heat dissipation performance of such large-capacity batteries, a heat transfer tube clamping part can also be provided at the part where the polar terminal of the single cell extends out of the avoidance hole; the heat transfer tube is fixed in the heat transfer tube clamping part. When the temperature of the large-capacity battery is higher than the set threshold, the large-capacity battery is cooled by introducing 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 introducing 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 working temperature.

[0098] In order to lead the thermal runaway flue gas out of the large-capacity battery housing, a pressure relief mechanism communicating with the inner cavity of the housing is provided on the housing; usually, the pressure relief mechanism is directly connected to the above-mentioned shared chamber.

[0099] When the energy storage device is assembled with the above large-capacity battery, when a thermal runaway occurs in an individual single cell in any large-capacity battery, due to the deformation of the single cell in the y direction, cracks will appear in the weld between the upper cover plate and the cylinder, and the thermal runaway flue gas will leak from the cracks of the single cell and diffuse into the large-capacity battery housing, increasing the pressure in the inner cavity of the housing, which is likely to cause the tearing of the weak part of the housing (for the housing of the above first structure, its weak part is usually the weld area between the cylinder assembly and the end plate assembly, and the housing top plate area around the avoidance hole), and in severe cases, it will cause the explosion of the large-capacity battery or even the energy storage device.

[0100] Based on the above problems, the utility model adds a clamping plate inside the outer shell. The clamping plate cooperates with the side plate of the outer shell to apply a clamping force to each single battery in the y direction, so that the single batteries in the large-capacity battery are restricted in three directions: x (in the x direction, based on the end plate assemblies at both ends, a clamping force can be applied to each single battery), y, and z (in the z direction, the sealing connector cooperates with the top plate and the bottom plate of the outer shell to hold each single battery), ensuring that the thermal runaway flue gas can be smoothly released from the explosion venting mechanism, reducing or even avoiding the problem that when a single battery undergoes thermal runaway, the housing of the single battery tears, leading to the intensification of thermal runaway and the spread of flue gas.

[0101] The following further describes the present utility model in conjunction with the accompanying drawings and specific embodiments.

[0102] Embodiment 1

[0103] As Figures 2 to 5 shown, the large-capacity battery in this embodiment includes an outer shell 1 and a plurality of single batteries 2 arranged in the outer shell 1 along the x direction.

[0104] The single battery 2 in this embodiment is a square-shell battery, and the number is 13. The inner cavity of each single battery 2 includes an electrolyte area and a gas area. In other embodiments, the number of single batteries 2 can be adjusted according to actual needs, and the form of the single battery 2 can also be adjusted according to actual needs.

[0105] As Figure 6 shown, it is an exploded structural schematic diagram of the outer shell 1 in this embodiment. The outer shell 1 is disassembled into a cylindrical body assembly 11 with open ends at both ends and end plate assemblies 12 covering the open ends of the cylindrical body assembly 11. Among them, the structure of the cylindrical body assembly 11 is as Figure 7 shown, including a cylinder and two bosses 112 for forming an electrolyte sharing chamber 3; both ends of the cylinder are open ends; the two bosses 112 are located on the inner surface of the bottom plate 1112 of the cylinder, have the same length as the cylinder, and extend along the x direction and are arranged in the y direction. The top surface of the boss 112 is the support surface for each single battery 2. In the y direction, a liquid channel is formed between the two bosses 112 as the electrolyte sharing chamber 3. The above cylindrical body assembly 11 can be integrally formed by an aluminum extrusion process.

[0106] On the top plate 1111 of the cylinder, a gas chamber 4 is provided along the x direction, and the gas chamber 4 is communicated with the gas areas in the inner cavities of the single batteries 2.

[0107] In some other embodiments, only the electrolyte sharing chamber 3 or the gas chamber 4 may be provided.

[0108] The top plate 1111 of the cylinder is provided with avoidance holes 113 through which the polar terminals of each single battery 2 can extend; as Figure 5As shown, in this embodiment, the polar terminal of the single cell 2 is an integral structure formed by the cooperation of the pole column 21 of the single cell 2 and the pole column adapter 22. The polar terminals of each single cell 2 extend out of the corresponding avoidance holes 113, and a sealing connector 18 is added between the avoidance holes 113 and the polar terminals. The sealing connector 18 includes a hollow member 181; the bottom of the hollow member 181 is used for sealing connection with the first area of the single cell 2, and the top of the hollow member 181 is sealedly connected with the second area of the cylinder top plate 1111; the first area is the area around any polar terminal on the upper cover plate of the single cell 2 of any one of the single cells 2; among them, the area around the polar terminal is the area around the insulating gasket on the polar terminal. The insulating gasket is a part on the single cell 2 for insulating between the polar terminal and the upper cover plate of the single cell 2. The second area is the area of the cylinder top plate 1111 corresponding to any one of the avoidance holes 113 on the cylinder top plate 1111; the area of the cylinder top plate 1111 corresponding to the avoidance hole 113 is the peripheral area on the outer surface of the cylinder top plate 1111 corresponding to any one of the avoidance holes 113; or the area of the cylinder top plate 1111 corresponding to the avoidance hole 113 is the hole wall of the avoidance hole 113.

[0109] Combined Figures 3 to 7 , it can be seen that in this embodiment, a clamping plate 7 is provided between the two cylinder side plates 1113 and the two second side walls of all the single cells 2, and the two surfaces of the clamping plate 7 are respectively in close contact with the cylinder side plate 1113 and the second side walls of each single cell 2; among them, the side plate of the housing 1 and the second side wall of the single cell 2 are both parallel to the xz plane.

[0110] In some other embodiments, a clamping plate 7 can be provided only between one of the cylinder side plates 1113 and one of the second side walls of all the single cells 2 opposite thereto. In this case, the two surfaces of the clamping plate 7 are also respectively in close contact with the cylinder side plate 1113 and the second side walls of each single cell 2; the other second side walls of all the single cells 2 are in close contact with the other cylinder side plate 1113. Based on the cooperation of the clamping plate 7 and the two cylinder side plates 1113, all the single cells 2 can also be clamped in the y direction. However, compared with this embodiment, when the gap between the second side wall of the single cell 2 and the cylinder side plate 1113 is relatively large, inserting the clamping plate 7 into this gap will cause the single cell 2 to have a relatively large offset in the y direction, which may further cause the polar terminals of each single cell 2 to be unable to extend out of the corresponding avoidance holes 113.

[0111] In order to make the second side walls of the single cells 2 bear force evenly, this embodiment preferably has the size of the clamping plate 7 approximately the same as that of the second side wall of the single cell 2 in the z direction. The two can be exactly equal, or the size of the clamping plate 7 can also be slightly smaller than the size of the second side wall of the single cell 2 to facilitate the assembly of the clamping plate 7.

[0112] Since the clamping plate 7 is placed inside the cavity of the housing 1, a material that does not react with the electrolyte should be selected to prepare the clamping plate 7. Additionally, the clamping plate 7 should have a certain rigidity to facilitate its insertion into the gap between the second sidewall of the single cell 2 and the side plate 1113 of the cylinder. Further, in the x-direction, the size of the clamping plate 7 in this embodiment is approximately the same as that of the side plate 1113 of the cylinder, and all single cells can be clamped at one time. In some other embodiments, the clamping plate 7 can be composed of multiple sub-clamping plates, each sub-clamping plate corresponding to a single cell and being disposed between the second sidewall of each single cell and the side plate 1113 of the cylinder. However, compared with this embodiment, its installation is more complex.

[0113] Combined Figure 2 and Figure 6 It can be seen that in this embodiment, a first through hole 5 communicating with the electrolyte sharing chamber 3 is opened in the end plate assembly 12, and an explosion relief mechanism 6 is connected at the first through hole 5.

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

[0115] First, in the x-direction, all single cells 2 are pushed into the cylinder assembly 11. After they are in place, the clamping plate 7 is inserted into the gap between the second sidewall of the single cell 2 and the side plate 1113 of the cylinder (see Figure 8 ), and in the y-direction, all single cells 2 are clamped. Then, the end plate assembly 12 is fixed to the two open ends of the cylinder assembly 11, so that the inner surface of the end plate assembly 12 closely adheres to the first sidewall of the outermost single cell 2 inside the cylinder assembly (the first sidewall of the single cell 2 is parallel to the yz plane), and in the x-direction, all single cells 2 are clamped. The area of the cylinder top plate 1111 corresponding to the avoidance hole 113 is fixedly sealed with the housing of the single cell 2 by using the sealing connector 18, and in the z-direction, all single cells 2 are clamped.

[0116] In this embodiment, each single cell 2 is clamped in the x, y, and z directions, ensuring that the hot runaway flue gas can be smoothly released from the explosion relief mechanism 6, reducing or even avoiding the problem that when the single cell 2 undergoes thermal runaway, the housing of the single cell 2 is torn, resulting in the intensification of thermal runaway and the spread of flue gas.

[0117] Embodiment 2

[0118] Different from Embodiment 1, the end plate assembly 12 in this embodiment has the following structure.

[0119] As Figure 9As shown in the figure, it is a schematic structural diagram of the end plate assembly 12 of this embodiment, including a first end plate 121, a second end plate 122, and a third end plate 126 that are parallel to each other; a first support rib 123 is arranged between the first end plate 121 and the second end plate 122 to form a gas channel 124. The third end plate 126 is closely attached to the inner surface of the second end plate 122 (the surface of the second end plate 122 close to the single battery 2 is defined as the inner surface).

[0120] It can be seen from Figure 9 that this embodiment includes two first support ribs 123. The two first support ribs 123 extend in the z direction and are arranged in the y direction, and a gas channel 124 is formed between the first end plate 121, the second end plate 122, and the two first support ribs 123. In the z direction, the sizes of the two first support ribs 123 are the same as the size of the second end plate 122. The gas channel 124 extends in the z direction, with the upper end port as the intake end of the gas channel 124 and the lower end port as the outlet end of the gas channel 124. This outlet end communicates with the first through hole 5 opened on the first end plate 121.

[0121] In some other embodiments, one or more than two first support ribs 123 can be arranged between the first end plate 121 and the second end plate 122, as long as it is ensured that a structurally stable gap can be formed between the first end plate 121 and the second end plate 122 as the gas channel 124.

[0122] When one first support rib 123 is adopted, the first support rib 123 can extend in the z direction and can be located in the middle of the first end plate 121 and the second end plate 122 in the y direction. However, compared with this embodiment, its structural stability is weaker.

[0123] When more than two first support ribs 123 are adopted, the first support ribs 123 can extend in the z direction and are arranged at equal intervals in the y direction. Compared with this embodiment, it has higher structural strength, but the processing cost is higher.

[0124] In some other embodiments, such as Figure 10As shown, the second end plate 122 can be fixed to the first end plate 121 by means of screws. It should be noted that in order to ensure the formation of a gas passage 124 between the second end plate 122 and the first end plate 121, in the x direction, the length of the screw should be greater than the gap between the second end plate 122 and the first end plate 121 and less than the distance between the inner surface of the second end plate 122 and the outer surface of the first end plate 121 (the surface close to each single battery 2 is defined as the inner surface). The screw head passes through the second end plate 122 and is connected to the first end plate 121. In order for the end plate assembly 12 to better extrude each single battery 2 as a whole, a gasket 125 is provided between the second end plate 122 and the first end plate 121, and the screw head sequentially passes through the second end plate 122, the gasket 125 and the first end plate 121 for connection, so as to prevent the gap between the second end plate 122 and the first end plate 121 from becoming smaller or even disappearing when extruding the single battery 2.

[0125] In this embodiment, the end plate assembly 12 is an integral part, that is, the first end plate 121, the second end plate 122 and the first support rib 123 are integral parts, and can be integrally formed by an aluminum extrusion process. Compared with the split parts, it has a stable structure and a lower processing cost.

[0126] In order to ensure that all the hot runaway flue gas enters the gas passage 124, in the y direction, it is preferably that the distance between two first support ribs 123 is greater than the size of the gas chamber 4, that is, the size of the intake end of the gas passage 124 is greater than the size of the outlet end of the gas chamber 4; when any single battery 2 has a thermal runaway, the flue gas in the inner cavity of the single battery 2 enters the gas chamber 4, and after spraying out of the gas chamber 4, it can all enter the gas passage 124 and push open the explosion venting mechanism 6 fixed at the second through hole 9 of the first end plate 121 and be discharged.

[0127] In this embodiment, the end plate assembly 12 is fixed to at least one open end of the cylinder assembly 11 in Embodiment 1, and the other open end can be sealed by another end plate assembly 12. The difference between this other end plate assembly 12 and the above-mentioned end plate assembly 12 is that the second through hole 9 is not provided on the first end plate 121.

[0128] For the convenience of description, according to different sealing objects, the first end plate 121 in this embodiment is divided into three regions, and the three regions are respectively defined as the first sub-end plate 1211, the second sub-end plate 1212 and the third sub-end plate 1213, as Figure 11 shown.

[0129] The first sub-end plate 1211 is used to seal the open end of the gas chamber 4 of the large-capacity battery. The shape of the first sub-end plate 1211 is adapted to the shape of the open end of the gas chamber 4, and its area can be slightly larger than the area of the open end of the gas chamber 4. It is fixed to the open end of the gas chamber 4 by means of fusion welding; its area can also be slightly smaller than the area of the open end of the gas chamber 4, and it is fixed to the open end of the gas chamber 4 by means of inlay welding.

[0130] The second sub-end plate 1212 is used to seal the open end of the electrolyte sharing chamber 3 of the large-capacity battery. The shape of the second sub-end plate 1212 is adapted to the shape of the open end of the electrolyte sharing chamber 3, and its area can be slightly larger than the area of the open end of the electrolyte sharing chamber 3. It is fixed to the open end of the electrolyte sharing chamber 3 by means of fusion welding; its area can also be slightly smaller than the area of the open end of the electrolyte sharing chamber 3, and it is fixed to the open end of the electrolyte sharing chamber 3 by means of inlay welding.

[0131] The third sub-end plate 1213 is used to seal the open end of the cylinder body of the large-capacity battery. The shape of the third sub-end plate 1213 is adapted to the shape of the open end of the cylinder body, and its area can be slightly larger than the area of the open end of the cylinder body. It is fixed to the open end of the cylinder body by means of fusion welding; its area can also be slightly smaller than the area of the open end of the cylinder body, and it is fixed to the open end of the cylinder body by means of inlay welding.

[0132] It should be noted that the first sub-end plate 1211, the second sub-end plate 1212 and the third sub-end plate 1213 in this embodiment are integral parts. In some other embodiments, a split structure can be adopted. However, compared with the integral part structure, firstly, its processing procedure is more complex. Secondly, since each sub-end plate needs to be connected to each other, each connection part belongs to a weak part or an easy leakage point, which leads to a weak sealing performance of the entire housing 1.

[0133] A first through hole 5 is opened in the first end plate 121 area corresponding to the second sub-end plate 1212 or the open end of the electrolyte sharing chamber 3. Figure 2 It can be seen that in this embodiment, a part of the first through hole 5 is located on the second sub-end plate 1212, and the other part is located on the third sub-end plate 1213. The explosion relief mechanism 6 is welded at the first through hole 5.

[0134] Combined with Figure 12 It can be seen that the shape of the second end plate 122 in this embodiment is adapted to the shape of the third sub-end plate 1213. In the yz plane, the orthographic projection of the second end plate 122 is located on the third sub-end plate 1213, and the projection area is less than or equal to that of the third sub-end plate 1213, so as to prevent the second end plate 122 from blocking the first through hole 5.

[0135] In some other embodiments, when the second end plate 122 has a relatively large dimension in the z direction and is fixed to the third sub-end plate 1213, it may block the first through hole 5, resulting in the inability of the gas passage 124 or the electrolyte sharing chamber 3 to communicate with the explosion relief mechanism 6. To solve this problem, a through hole or notch that penetrates the first through hole 5 may be provided in the second end plate 122 to ensure the communication between the first through hole 5 and the electrolyte sharing chamber 3 or the gas passage 124.

[0136] The end plate assembly 12 is fixed to the open end of the cylindrical body assembly 11, and cooperates with the explosion relief mechanism 6 to seal the open end of the cylindrical body while sealing the open ends of the gas chamber 4 and the electrolyte sharing chamber 3. Through the gas passage 124 on the end plate assembly 12, the gas chamber 4 and the electrolyte sharing chamber 3 are communicated. When any single battery 2 undergoes thermal runaway and the flue gas in its inner cavity rushes out from the gas port, it will sequentially pass through the gas chamber 4 and the gas passage 124, and push open the explosion relief mechanism 6 and discharge from the explosion relief mechanism 6.

[0137] When the gas chamber 4 serves as an explosion relief passage, the first through hole 5 is located in the area of the first end plate 121 opposite to the open end of the electrolyte sharing chamber 3. The first through hole 5 also serves as an operation port for the unpacking device. The unpacking device extends into the electrolyte sharing chamber 3 through the first through hole 5 to unpack each single battery 2, so that the electrolyte areas in the electrolyte sharing chamber 3 and the inner cavities of each single battery 2 are communicated (specifically, when unpacking, the unpacking device extends into the electrolyte sharing chamber 3 through the first through hole 5 and opens the sealing film sealed at the opening of the lower cover plate of each single battery 2. Specifically, the sealing film can adopt the sealing films disclosed in Chinese patents CN218525645U and CN218525614U). In addition, the first through hole 5 can also serve as a liquid injection port. After the electrolyte areas in the inner cavities of each single battery 2 and the electrolyte sharing chamber 3 are communicated, electrolyte can be injected again into the inner cavities of each single battery 2 and the electrolyte sharing chamber 3 through the first through hole 5 to ensure the continuity of the electrolyte. After the liquid injection is completed, the explosion relief mechanism 6 is hermetically welded to partial areas of the second sub-end plate 1212 and the third sub-end plate 1213 around the first through hole 5. Compared with separately providing the first through hole 5, the operation port for the unpacking device or the liquid injection port on the end plate assembly 12, the overall structural strength of the end plate assembly 12 is relatively high, and the structure is simple and convenient for processing.

[0138] A second through hole 9 may also be provided in the area of the first end plate 121 corresponding to the open end of the gas chamber 4. After injecting liquid through the second through hole 9, the continuity of the electrolyte in the electrolyte sharing chamber 3 and the inner cavities of each single battery 2 can also be ensured. After the liquid injection is completed, the sealing sheet is sealed to partial areas of the first sub-end plate 1211 and the third sub-end plate 1213 around the second through hole 9.

[0139] When the gas chamber 4 serves as a gas sharing chamber, in this embodiment, a second through hole 9 can also be opened in the area of the first end plate 121 corresponding to the open end of the gas chamber 4. In this embodiment, the second through hole 9 is located in part of the area of the first sub-end plate 1211 and the third sub-end plate 1213, and the second through hole 9 is used as a liquid injection port. The electrolyte can be injected into the gas chamber 4 through the second through hole 9 to dissolve the sealing film sealed at the top opening part of each single battery 2 (the sealing film disclosed in Chinese patents CN218525645U and CN218525614U can be used. Specifically, when injecting liquid, the entire large-capacity battery can be inverted so that the sealing film is fully dissolved), so that the gas chamber 4 is communicated with the inner cavities of each single battery 2; at the same time, after the large-capacity battery is placed upright, after injecting liquid through the second through hole 9, the continuity of the electrolyte in the electrolyte sharing chamber 3 and the inner cavities of each single battery 2 can also be ensured. After the liquid injection is completed, the sealing piece is sealed on the part of the first sub-end plate 1211 and the third sub-end plate 1213 around the second through hole 9.

[0140] As Figure 13 shown, in this embodiment, by adjusting the dimension of the third end plate 126 in the x direction, all the single batteries 2 are clamped in the x direction, avoiding the problem that the single battery 2 deforms in the x direction and tears the connection part between the upper cover plate and its first side wall; at the same time, the stability of each single battery 2 in the inner cavity of the housing 1 can also be improved, and the problem that each single battery 2 bulges and causes the reduction of the cycle performance of the large-capacity battery can be prevented. In addition, the third end plate 126 can be used to further avoid the influence of the thermal runaway flue gas on the outermost single battery 2.

[0141] It should be noted that the dimension of the third end plate 126 in the z direction can be reduced so that it does not block the first through hole 5, or a through hole or a notch can be opened in the part of the third end plate 126 corresponding to the first through hole 5 to ensure the connectivity of the gas chamber 4, the gas channel 124, the electrolyte sharing chamber 3 and the explosion venting mechanism 6.

[0142] Embodiment 3

[0143] Different from the above embodiments, in this embodiment, the structure of the sealing connector 18 is optimized to further improve the sealing performance of the avoidance hole 113 part.

[0144] When using the sealing connector 18 in Embodiment 1 to realize the fixed sealing of the cylindrical top plate area corresponding to the avoidance hole 113 and the housing of the single battery 2, in actual processing and application, the following problems are found:

[0145] 1. When the bottom of the hollow member 181 is hermetically connected to the area around the polarity terminal of the upper cover plate of the single battery 2 by welding, the upper cover plates of some single batteries 2 are extremely likely to be damaged, resulting in the scrapping of the single battery 2;

[0146] 2. In the peripheral area of the polar terminal on the upper cover plate of some single cells 2, welding may not be possible due to the presence of other structures.

[0147] 3. Even if there is no visible damage during the processing, in actual applications, when thermal runaway occurs in an individual single cell 2 in a large-capacity battery with the above-mentioned sealing connector 18, the thermal runaway flue gas will leak from the connection area around the polar terminal on the upper cover plate of the single cell 2. Therefore, if the above-mentioned multiple large-capacity batteries are assembled into an energy storage device, after thermal runaway occurs, the thermal runaway flue gas may leak and diffuse from the welding part around the polar terminal on the upper cover plate of the single cell 2, posing a certain safety hazard. Based on this problem, after disassembling the above-mentioned large-capacity battery after thermal runaway, it is found that cracks appear in the connection area around the polar terminal on the upper cover plate of the single cell 2 that has experienced thermal runaway (the connection area with the bottom of the sealing connector 18). After analysis, the reason for this phenomenon is that there is a certain weak area around the polar terminal on the upper cover plate of the single cell 2. If the connection area falls into this weak area, the above problems will occur. The reason is that the welding process has a certain damage to this weak area, which further causes this area to be unable to withstand the thermal runaway pressure. When thermal runaway occurs, cracks are generated, resulting in the leakage of thermal runaway flue gas from this area.

[0148] Based on this, in this embodiment, it is considered to optimize the structure of the sealing connector 18, mainly adjusting the size and shape of the bottom open end 1811 of the hollow member 181, so that the orthographic projection of the bottom open end 1811 of the hollow member 181 on the upper cover plate of the single cell 2 covers the weak area around the polar terminal on the upper cover plate of the single cell 2; thereby ensuring that when welding the bottom of the hollow member 181 and the area around the polar terminal on the upper cover plate of the single cell 2, the weak area around the polar terminal on the upper cover plate of the single cell 2 can be avoided, and damage to the weak area during the welding process can be avoided.

[0149] It should be noted that:

[0150] 1. For single cells 2 produced by different manufacturers, the size, position, and shape of the corresponding weak areas are also different. Therefore, when processing the sealing connector 18, in this embodiment, it is first necessary to determine the size, position, and shape of the weak area of the single cell 2, and adjust the size and shape of the bottom open end 1811 of the hollow member 181 for single cells 2 produced by different manufacturers.

[0151] 2. In this embodiment, the area that is easily damaged by welding, or the area where welding cannot be performed, or the area where the pressure-bearing performance is reduced due to welding, is all referred to as the weak area.

[0152] Such as Figure 14As shown, it is a schematic structural diagram of the sealing connector 18 of this embodiment. It can be seen from the figure that the sealing connector 18 of this embodiment includes a hollow member 181, which can also be called a hollow pipe fitting.

[0153] Both ends of the hollow member 181 are open ends. For the convenience of description, one of the open ends is defined as the bottom open end 1811, and the other open end is defined as the top open end 1812.

[0154] The bottom of the hollow member 181 is used for sealing connection with the first area of the single cell 2. Here, the first area is the peripheral area of the weak area of the upper cover plate of the single cell 2; in order to seal-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 plate of the single cell 2 covers the weak area around the polar terminal on the upper cover plate of the single cell 2. 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 plate of the single cell 2 will necessarily cover the polar terminal on the upper cover plate of the single cell 2.

[0155] During welding, the hollow member 181 can be first positioned on the upper cover plate of the single cell 2, and the position of the hollow member 181 can be adjusted so that the orthographic projection of the bottom open end 1811 of the hollow member 181 on the upper cover plate of the single cell 2 covers the weak area around the polar terminal on the upper cover plate of the single cell 2; then, the bottom of the hollow member 181 and the upper cover plate of the single cell 2 are welded. Since the two welded surfaces are perpendicular to each other, the reliability and tightness of the welded part may be relatively weak.

[0156] To solve this problem, as Figure 15 and Figure 16 shown, a bottom plate 182 can be fixed to the bottom open end 1811 of the hollow member 181, and a third through hole 1820 is opened on the bottom plate 182. The size of the third through hole 1820 needs to ensure that the polar terminal of the single cell 2 can pass through, and the bottom plate 182 is welded to the peripheral area of the weak area around the polar terminal on the upper cover plate of the single cell 2.

[0157] 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. It can be seen from the figure that the third through hole 1820 of this embodiment is a waist-shaped first through hole 5, and the corresponding weak area of the single cell 2 is also a waist-shaped area; preferably, the orthographic projection of the third through hole 1820 on the upper cover plate of the single cell 2 covers the weak area around the polar terminal on the upper cover plate of the single cell 2; in this way, when the bottom plate 182 is welded to the upper cover plate of the single cell 2, the welded part will necessarily be located outside the weak area.

[0158] The bottom plate 182 can be fixed to the bottom open end 1811 of the hollow member 181 by welding, or the bottom plate 182 and the hollow member 181 can be processed into an integral part by integral processing. Compared with the split part, the integral part has a lower processing cost and higher structural stability.

[0159] In some other embodiments, such as Figure 17 As shown, a second annular plate 183 can also be fixedly sleeved outside the bottom of the hollow member 181, and the second annular plate 183 is welded to the outer periphery of the weak area around the polarity terminal of the upper cover plate of the single battery 2. Since the bottom open end 1811 of the hollow member 181 orthogonally projects onto the upper cover plate of the single battery 2 to cover the weak area around the polarity terminal on the upper cover plate of the single battery 2, and the second annular plate 183 is located outside the bottom of the hollow member 181, its inner diameter must be larger than the diameter of the bottom open end 1811 of the hollow member 181. In this way, when the second annular plate 183 is welded to the upper cover plate of the single battery 2, the welding part must be located in the outer periphery of the weak area. The second annular plate 183 can be fixed to the bottom open end 1811 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 integral processing. Compared with the split part, the integral part has a lower processing cost and higher structural stability.

[0160] The top of the hollow member 181 is used for sealing connection with the cylindrical top plate area around the avoidance hole 113; in this embodiment, the size and shape of the top open end 1812 of the hollow member 181 are mainly related to the shape of the avoidance hole 113. For example, the avoidance hole 113 of the large-capacity battery adapted by the hollow member 181 in this embodiment is a round hole, so the top open end 1812 of the hollow member 181 is circular and its diameter is slightly smaller than the diameter of the avoidance hole 113. In this embodiment, the outer peripheral surface of the hollow member 181 is used for closely fitting with the hole wall of the avoidance hole 113, and the hollow member 181 and the avoidance hole 113 are welded and sealed by laser welding; the welding area of the hollow member 181 and the avoidance hole 113 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 113.

[0161] Such as Figure 18 As shown, it is a partial explosion schematic diagram of the large-capacity battery in this embodiment. In order to clearly show the connection positions of the sealing connector 18 with the upper cover plate of the single battery 2 and the cylindrical top plate area around the avoidance hole 113, in Figure 18 three states are shown. At position a, the bottom plate 182 of the sealing connector 18 is welded and sealed with the outer periphery of the weak area of the upper cover plate; at position b, the pole column 21 of the single battery 2 is located in the avoidance hole 113 and the welding of the sealing connector 18 has not been completed; at position c, the single battery 2 is not installed at the corresponding part of the avoidance hole 113, and the structure of the avoidance hole 113 can be clearly shown.

[0162] In some other embodiments, such as Figure 19 shown (different from Figure 14 , the third through hole 1820 on the bottom plate 182 of the sealing connection member 18 is a circular hole), a first annular plate 184 can also be fixedly sleeved outside the top of the hollow member 181, and the first annular plate 184 is welded and sealed to the second area of the housing 1; the second area is the outer surface area of the cylindrical top plate around the avoidance hole 113. The first annular plate 184 can be fixedly arranged at the open end 1812 of the top of the hollow member 181 by welding.

Claims

1. A large capacity battery, characterized in that: The invention comprises a housing, at least one clamping plate located in the housing, and n single cells; the n single cells are arranged in the housing along the x direction; wherein n is an integer greater than 1; The housing is provided with at least one shared chamber extending in the x-direction; The outer shell top plate is provided with avoidance holes corresponding to the polarity terminals of each single battery; each single battery polarity terminal extends out of the corresponding avoidance hole, and the outer shell top plate area corresponding to the avoidance hole is fixedly sealed with the single battery shell; The clamping plate is arranged between the shell side plate and the second side wall of each single cell, and the two surfaces of the clamping plate are respectively in close contact with the shell side plate and the second side wall of each single cell; wherein the shell side plate and the second side wall of the single cell are parallel to the xz plane.

2. The large-capacity battery according to claim 1, characterized in that: There are two clamping plates, one of which is arranged between a side plate of the housing and a second side wall of each single cell, and the other clamping plate is arranged between another side plate of the housing and another second side wall of each single cell.

3. The large-capacity battery according to claim 1, characterized in that: In the z direction, the size of the clamping plate is equal to the size of the second side wall of the single battery.

4. The large-capacity battery according to any one of claims 1 to 3, characterized in that: The shared chamber is an electrolyte shared chamber; The housing includes a cylinder assembly with two open ends and an end plate assembly covering the two open ends of the cylinder assembly; A liquid channel extending along the x direction is provided at the bottom of the cylinder assembly, serving as an electrolyte sharing chamber, and the inner cavity of the electrolyte sharing chamber is connected to the inner cavities of all the single cells.

5. The large-capacity battery according to claim 4, characterized in that: The cylinder assembly includes a cylinder and two bosses arranged on the inner bottom surface of the cylinder and extending in the x direction and arranged in the y direction with the same length as the cylinder. The top surface of the boss is the supporting surface of each single battery. In the y direction, a liquid channel is formed between the two bosses as a shared chamber for the electrolyte.

6. The large-capacity battery according to claim 5, characterized in that: It also includes another shared chamber, which is a gas chamber arranged on the top plate of the housing, covering the gas ports on the top of each monomer; The gas port is a through hole, and the inner cavity of the gas chamber is directly connected to the gas area of ​​the inner cavity of each single battery through the gas port; Alternatively, an explosion relief membrane is provided at the gas port, and when the explosion relief membrane at the gas port of any single cell is broken by the smoke in the inner cavity, the gas area in the inner cavity of the single cell is connected with the inner cavity of the gas chamber.

7. The large-capacity battery according to claim 6, characterized in that: The end plate assembly includes a first end plate, a second end plate and a third end plate; A first through hole is formed on the first end plate; the first end plate cooperates with an explosion relief mechanism fixed at the first through hole to seal the open end of the gas chamber, the open end of the electrolyte shared chamber and the open end of the cylinder of the large-capacity battery; The second end plate is fixedly connected to the first end plate, the two are parallel to each other, and there is a gap between them, the gap is used as a gas channel; the gas channel extends along the z direction, the gas inlet end of the gas channel is used to communicate with the gas chamber, and the gas outlet end of the gas channel is connected with the second through hole; in the z direction, the gas inlet end of the gas channel is higher than the gas outlet end of the gas channel; Two surfaces of the third end plate are respectively closely attached to the first side wall of the outermost single battery and the inner surface of the second end plate.

8. The large-capacity battery according to claim 7, characterized in that: Two first support ribs are integrally arranged between the second end plate and the first end plate, each first support rib extends along the z direction, and the two first support ribs are arranged along the y direction, and a gas channel is formed between the second end plate, the first end plate and the two first support ribs.

9. The large-capacity battery according to claim 8, characterized in that: It also includes 2n sealing connectors; the housing top 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 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 peripheral area of ​​the weak area are welded and sealed, and the top of the hollow component and the top plate area of ​​the shell 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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