Cover plate assembly of battery monomer, battery shell, battery monomer, battery pack and power utilization device

Abstract

The utility model discloses a battery cell cover plate assembly, battery shell, battery cell, battery pack and electric device wherein the battery cell cover plate assembly comprises a cover plate body and a cap, the cover plate body is suitable for connecting the shell of the battery cell, the cover plate body is provided with a communication port penetrating through the cover plate body, the communication port is suitable for communicating with a first accommodating cavity of the shell, and the first accommodating cavity is provided with a second accommodating cavity. The cover cap is arranged on the cover plate body and right faces the communicating opening, the cover cap is fixedly connected with the cover plate body, at least part of the cover cap protrudes in the direction away from the communicating opening to form a protruding part, a second containing cavity communicating with the communicating opening is formed in the side, facing the communicating opening, of the protruding part, the second containing cavity is used for temporarily storing gas, and at least one anti-explosion valve is arranged on the protruding part; and the anti-explosion valve is configured to be damaged to be communicated with the second accommodating cavity after the internal part of the pole core reaches a set pressure. Therefore, the use safety of the battery monomer can be ensured to a certain extent, and the volume energy density of the battery monomer can be improved, so that the working performance of the battery monomer is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a cover plate assembly of a battery cell, a battery case, a battery cell, a battery pack and an electric device. Background Art

[0002] Batteries have received extensive attention due to their advantages such as high energy density and environmental friendliness, and are widely used in large-scale equipment such as energy storage devices and electric vehicles. However, the safety of batteries is the most important factor affecting their development. For example, when the water content in the battery core exceeds the standard, the SEI membrane (Solid Electrolyte Interface membrane) is unstable, or when the battery is overcharged, over-discharged, short-circuited, squeezed or subjected to other abuse conditions, it will cause gas generation, ignition or even explosion inside the battery. Currently, the common method to solve these problems is to add an explosion-proof valve on the top cover of the battery. When the above situation occurs in the battery and gas is generated inside the battery, when the gas pressure inside the battery reaches the bursting pressure of the explosion-proof valve, the explosion-proof sheet on the top cover ruptures, so that the gas inside the battery is discharged from the explosion-proof valve port, preventing the battery from exploding due to bloating.

[0003] However, due to the improvement of the volume utilization rate of the existing battery case, the explosion-proof valve is close to the electrode core, resulting in the inability to store the gas generated inside the battery, which easily causes serious expansion of the electrode core and affects the use safety of the battery. Summary of the Utility Model

[0004] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, the first object of the utility model is to propose a cover plate assembly of a battery cell, which can ensure the use safety of the battery cell to a certain extent while realizing the high volume energy density of the battery cell, and solves the technical problems such as low volume energy density and poor use safety of the battery cell in the prior art.

[0005] The second object of the utility model is to propose a battery case having the above cover plate assembly.

[0006] The third object of the utility model is to propose a battery cell having the above cover plate assembly or battery case.

[0007] The fourth object of the utility model is to propose a battery pack having the above battery cell.

[0008] The fifth object of the utility model is to propose an electric device having the above battery pack.

[0009] The cover assembly of a battery cell according to an embodiment of the present utility model includes: a cover body adapted to be connected to the housing of the battery cell. The cover body is provided with a communication port penetrating therethrough, and the communication port is adapted to communicate with a first accommodation cavity of the housing. A pole core is adapted to be placed in the first accommodation cavity. A cap is disposed on the cover body and faces the communication port. The cap is fixedly connected to the cover body. At least a part of the cap protrudes away from the communication port to form a protruding portion. A second accommodation cavity communicating with the communication port is formed on a side of the protruding portion facing the communication port. The second accommodation cavity is used for caching gas. At least one explosion-proof valve is provided on the protruding portion, and the explosion-proof valve is configured to be damaged after the internal pressure of the pole core reaches a set pressure to communicate with the second accommodation cavity.

[0010] The cover assembly of a battery cell according to an embodiment of the present utility model, by providing a fixedly connected cover body and a cap, the cooperation of the cover body and the cap can realize the formation of a protruding portion with a certain protruding height on the cover assembly, so as to reduce the forming difficulty of the protruding portion and is beneficial to ensuring the protruding height of the protruding portion. This facilitates arranging at least a part of the tab of the battery cell inside the cover assembly, so as to avoid the tab occupying too much space inside the housing of the battery cell to a certain extent, improve the space utilization rate of the housing, and facilitate ensuring the volumetric energy density of the battery cell. At the same time, by forming a second accommodation cavity communicating with the communication port on a side of the protruding portion facing the communication port, using the second accommodation cavity to cache gas, and providing at least one explosion-proof valve on the protruding portion, it is convenient to discharge the high-temperature and high-pressure gas generated when the battery cell undergoes thermal runaway, avoiding the serious expansion of the pole core of the battery cell to a certain extent, thereby ensuring the use safety of the battery cell to a certain extent and extending the cycle life of the battery cell. That is to say, the cover assembly of the present application can, while realizing the improvement of the volumetric energy density of the battery cell, also ensure the use safety of the battery cell to a certain extent and extend the cycle life of the battery cell.

[0011] In some embodiments, the second accommodation cavity is used for accommodating at least a part of the tab of the battery cell.

[0012] In some embodiments, a plurality of the explosion-proof valves are provided on the protruding portion.

[0013] In some embodiments, at least one of the explosion-proof valves is disposed on a wall surface of the protruding portion facing the communication port.

[0014] In some embodiments, at least one side wall of the protruding portion is provided with an installation port penetrating therethrough, and an explosion-proof sheet is installed in the installation port, and the explosion-proof sheet forms the explosion-proof valve.

[0015] In some embodiments, the area of the side wall provided with the mounting opening is S1, the area of the mounting opening is S2, and S1 and S2 satisfy: 0.05 ≤ S2 / S1 ≤ 0.95.

[0016] In some embodiments, the explosion-proof sheet is provided with a first notch.

[0017] In some embodiments, the cover plate assembly further includes a protection sheet, and the protection sheet is disposed at the mounting opening and on a side of the explosion-proof sheet away from the second accommodating cavity.

[0018] In some embodiments, the thickness of the protection sheet ranges from 0.1 mm to 1.5 mm.

[0019] In some embodiments, at least one side wall of the convex portion is provided with a second notch, and the second notch forms the explosion-proof valve.

[0020] In some embodiments, the second notch includes at least one arc-shaped notch and / or at least one straight notch.

[0021] In some embodiments, the thickness of the side wall provided with the second notch is greater than 0.2 mm.

[0022] In some embodiments, the area of the side wall provided with the second notch is S1, the covered area of the projection of the second notch on the first plane is S3, and S1 and S3 satisfy: 0.05 ≤ S3 / S1 ≤ 0.95, and the first plane is perpendicular to the thickness direction of the cover plate body.

[0023] In some embodiments, the thickness W of the cap ranges from 0.3 mm to 5 mm; and / or, the protruding height H1 of the convex portion ranges from 2 mm to 50 mm.

[0024] In some embodiments, on the first plane, the projected area of the communication port is S1, the projected area of the cover plate body excluding the communication port is S4, and S1 and S4 satisfy: 0.1 ≤ S1 / S4 ≤ 3, and the first plane is perpendicular to the thickness direction of the cover plate body.

[0025] In some embodiments, the cover plate assembly further includes a terminal assembly, and the terminal assembly is disposed on the cover plate body; the protruding height H1 of the convex portion and the height H2 of the terminal assembly protruding from the cover plate body satisfy: -5 mm ≤ H1 - H2 ≤ 5 mm.

[0026] In some embodiments, the cover plate assembly further includes a liquid injection hole, and the liquid injection hole is disposed on the cover plate body and / or the convex portion, and the liquid injection hole communicates with the first accommodating cavity.

[0027] In some embodiments, on the protruding direction towards the protruding portion, a mounting groove is provided on the first side wall of the cover plate body, and the cap has a mounting flange that cooperates with the mounting groove, and the mounting flange is limited within the mounting groove.

[0028] In some embodiments, the mounting groove surrounds the outer periphery of the communication port and is communicated with the communication port, and the shape of the mounting flange matches the shape of the mounting groove.

[0029] In some embodiments, the mounting groove extends in a direction away from the communication port, and the value range of the extension length of the mounting groove on the same side of the communication port is 0.5 mm to 3 mm.

[0030] The battery housing according to an embodiment of the present invention includes: a housing, a first accommodation cavity with an opening is formed inside the housing, and a pole core is adapted to be placed in the first accommodation cavity; a cover plate assembly, which is the aforementioned cover plate assembly, and the cover plate assembly is provided at the opening.

[0031] By adopting the aforementioned cover plate assembly in the battery housing according to an embodiment of the present invention, when the battery housing is applied to a battery cell, while achieving a high volume energy density of the battery cell, the use safety of the battery cell can also be guaranteed to a certain extent.

[0032] The battery cell according to an embodiment of the present invention includes a pole core and the aforementioned cover plate assembly or the aforementioned battery housing, and at least a part of the pole ear of the pole core is provided in the second accommodation cavity.

[0033] By adopting the aforementioned cover plate assembly in the battery cell according to an embodiment of the present invention, while achieving a high volume energy density of the battery cell, the use safety of the battery cell can also be guaranteed to a certain extent.

[0034] In some embodiments, the pole ear and the cap are arranged at intervals, and the value range of the minimum distance between the pole ear and the cap is 1 mm to 50 mm.

[0035] The battery pack according to an embodiment of the present invention includes a plurality of the aforementioned battery cells.

[0036] By adopting the aforementioned battery cells in the battery pack according to an embodiment of the present invention, it is beneficial to improve the energy density of the battery pack and ensure the use safety of the battery pack.

[0037] The electrical device according to an embodiment of the present invention includes the aforementioned battery pack.

[0038] According to the electrical device of the embodiment of the present utility model, by adopting the aforementioned battery pack, it is beneficial to improve the working performance of the electrical device and ensure the use safety of the electrical device.

[0039] The additional aspects and advantages of the present utility model will become apparent in the following description, or be understood through the practice of the present utility model. Brief Description of the Drawings

[0040] The above and / or additional aspects and advantages of the present utility model will become apparent and be easily understood from the description of the embodiments in conjunction with the following drawings, where:

[0041] Figure 1 is an exploded view of a partial structure of a battery cell according to some embodiments of the first aspect of the present utility model.

[0042] Figure 2 is Figure 1 an enlarged view of region I in

[0043] Figure 3 is a cross-sectional view of a partial structure of a battery cell according to some embodiments of the first aspect of the present utility model.

[0044] Figure 4 is a schematic diagram of a cap according to some embodiments of the second aspect of the present utility model.

[0045] Figure 5 is a schematic diagram of a cap according to some embodiments of the first aspect of the present utility model.

[0046] Figure 6 is an exploded view of a partial structure of a battery cell according to some embodiments of the third aspect of the present utility model.

[0047] Figure 7 is a schematic diagram of a cap according to some embodiments of the third aspect of the present utility model.

[0048] Figure 8 is an exploded view of a partial structure of a battery cell according to some embodiments of the fourth aspect of the present utility model.

[0049] Figure 9 is a schematic diagram of a cap according to some embodiments of the fourth aspect of the present utility model.

[0050] Figure 10 is a schematic diagram of a cap according to some embodiments of the fifth aspect of the present utility model.

[0051] Figure 11 is a schematic diagram of a cap according to some embodiments of the sixth aspect of the present utility model.

[0052] Figure 12 is a schematic diagram of a cap according to some embodiments of the seventh aspect of the present utility model.

[0053] Figure 13 Schematic diagram of the cap for some embodiments of the eighth aspect of the present utility model.

[0054] Figure 14 Cross-sectional view of the cap for some embodiments of the ninth aspect of the present utility model.

[0055] Figure 15 Exploded view of a partial structure of a battery cell for some embodiments of the tenth aspect of the present utility model.

[0056] Figure 16 Schematic diagram of the cap for some embodiments of the tenth aspect of the present utility model.

[0057] Reference numerals:

[0058] 1000, battery cell;

[0059] 100, cover plate assembly;

[0060] 110, cover plate body;

[0061] 111, communication port;

[0062] 112, first side wall; 1121, installation groove;

[0063] 120, cap;

[0064] 121, protrusion; 1211, second accommodation cavity; 1212, installation opening; 1213, second notch; 122, installation flange;

[0065] 130, explosion-proof valve; 131, explosion-proof sheet;

[0066] 140, pole column assembly;

[0067] 200, outer shell; 210, first accommodation cavity; 211, opening;

[0068] 300, tab;

[0069] 500, insulating part;

[0070] 600, battery housing. Detailed description of the embodiments

[0071] The embodiments of the present utility model will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary and are only used to explain the present utility model and should not be construed as a limitation of the present utility model.

[0072] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", 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, and therefore should not be construed as a limitation to the present utility model.

[0073] The cover assembly 100 of the battery cell 1000 according to an embodiment of the present utility model will be described below with reference to the accompanying drawings of the specification.

[0074] Combined Figure 1 , Figure 2 and Figure 3 As shown, the cover assembly 100 of the battery cell 1000 according to an embodiment of the present utility model includes: a cover body 110 and a cap 120.

[0075] Among them, as Figure 1 and Figure 3 shown, the cover body 110 is adapted to be connected to the housing 200 of the battery cell 1000. The cover body 110 is provided with a communication port 111 penetrating therethrough. The communication port 111 is adapted to communicate with the first accommodation cavity 210 of the housing 200. The first accommodation cavity 210 is adapted to place the electrode core. Here, it means that the cover body 110 is provided with a communication port 111, and the communication port 111 penetrates the cover body 110 to facilitate the communication between the opposite sides of the cover body 110. At the same time, the battery cell 1000 has a housing 200, and the first accommodation cavity 210 for placing the electrode core is provided in the housing 200. The cover body 110 is connected to the housing 200 and the communication port 111 on the cover body 110 communicates with the first accommodation cavity 210 of the housing 200, which is convenient for forming the battery cell 1000. At the same time, the housing 200 can also be used to support the cover body 110 to ensure the position stability of the cover body 110, which is beneficial to ensuring the working performance of the cover body 110.

[0076] In addition, the communication port 111 is communicated with the first accommodation cavity 210 of the housing 200 so that the high-temperature and high-pressure gas generated by the electrode core in the first accommodation cavity 210 during thermal runaway can be discharged through the communication port 111 to improve the use safety of the electrode core.

[0077] Combined Figure 1 , Figure 2 and Figure 3As shown, the cap 120 is provided on the cover plate body 110 and faces the communication port 111. The cap 120 is fixedly connected to the cover plate body 110. At least a part of the cap 120 protrudes away from the communication port 111 to form a protruding portion 121. A second accommodation cavity 1211 communicating with the communication port 111 is formed on the side of the protruding portion 121 facing the communication port 111. The second accommodation cavity 1211 is used for buffering gas. At least one explosion-proof valve 130 is provided on the protruding portion 121. The explosion-proof valve 130 is configured to be damaged after the internal pressure of the electrode core reaches a set pressure to communicate with the second accommodation cavity 1211.

[0078] Here, it means that when the cap 120 is provided on the cover plate body 110, the second accommodation cavity 1211 of the protruding portion 121 on the cap 120 communicates with the communication port 111. Since the communication port 111 communicates with the first accommodation cavity 210 of the outer shell 200, the cooperative connection between the first accommodation cavity 210 and the second accommodation cavity 1211 is realized. In this way, when thermal runaway occurs in the electrode core in the first accommodation cavity 210, the high-temperature and high-pressure gas generated can be discharged to the second accommodation cavity 1211 through the communication port 111, so as to realize buffering gas by the second accommodation cavity 1211 and avoid the phenomenon that too much gas is stored in the first accommodation cavity 210, resulting in the swelling of the battery cell 1000 and squeezing adjacent battery cells 1000.

[0079] At the same time, at least one explosion-proof valve 130 is provided on the protruding portion 121, and the explosion-proof valve 130 is set to be damaged after the internal pressure of the electrode core reaches a set pressure to communicate with the second accommodation cavity 1211. So that when the internal gas pressure of the battery cell 1000 reaches the upper limit, the explosion-proof valve 130 can be effectively opened for exhaust, which can well guide the gas to be discharged from the inside of the battery cell 1000, that is, make the large amount of gas generated inside the battery cell 1000 be discharged more quickly, and then realize timely elimination of explosion hazards, thereby improving the use safety of the battery cell 1000.

[0080] In addition, setting the explosion-proof valve 130 on the protruding portion 121 can also make the explosion-proof valve 130 far away from the electrode core, improve the opening function of the explosion-proof valve 130, and avoid the failure of the explosion-proof valve 130 to a certain extent.

[0081] That is to say, in the present application, the explosion-proof valve 130 is provided on the convex portion 121. On the one hand, this can keep the explosion-proof valve 130 away from the electrode core, reducing the opening difficulty of the explosion-proof valve 130, and thus ensuring the working performance of the explosion-proof valve 130. On the other hand, since the convex portion 121 forms a second accommodation cavity 1211, when gas is generated inside the battery cell 1000, part of the gas can be stored in the second accommodation cavity 1211, avoiding the phenomenon that the battery cell 1000 bulges and squeezes adjacent battery cells 1000. Moreover, the second accommodation cavity 1211 can be used to store gas, concentrating the gas. In this way, when the internal gas pressure reaches the upper limit, the explosion-proof valve 130 can be effectively opened for exhaust, guiding the gas to be discharged from the inside of the battery cell 1000 well, that is, enabling the large amount of gas generated inside the battery cell 1000 to be discharged more quickly, and further realizing the timely elimination of explosion hazards, thereby improving the use safety of the battery cell 1000.

[0082] In addition, by arranging the explosion-proof valve 130 on the convex portion 121, it is also possible to support the explosion-proof valve 130 by means of the cap 120, so as to improve the position stability of the explosion-proof valve 130, and thus ensure the working performance of the explosion-proof valve 130.

[0083] It should be noted that in the present application, the cover plate assembly 100 is set to include a cover plate body 110 and a cap 120, and the cover plate body 110 and the cap 120 are fixedly connected, so that the cover plate body 110 and the cap 120 form two separate structures. At the same time, the cover plate body 110 and the cap 120 are used in cooperation to form the second accommodation cavity 1211. In this way, compared with directly stamping the cover plate body 110 to form an accommodation cavity, not only can the forming difficulty of the second accommodation cavity 1211 be reduced, but also the space of the second accommodation cavity 1211 in the height direction can be ensured.

[0084] That is to say, in the present application, by providing a communication port 111 penetrating through the cover plate body 110, arranging the cap 120 opposite to the communication port 111, and forming a second accommodation cavity 1211 communicating with the communication port 111 in the convex portion 121, it can be ensured that the second accommodation cavity 1211 can effectively accommodate and buffer gas, avoiding the expansion of the battery cell 1000 to a certain extent.

[0085] It should also be noted that the above-mentioned fixed connection between the cover plate body 110 and the cap 120 can be welding, bonding or bolt connection, etc.

[0086] That is to say, in the present application, the cover plate assembly 100 is configured to include a cover plate body 110 and a cap 120. A communication port 111 is formed on the cover plate body 110, and a second accommodation cavity 1211 communicating with the communication port 111 is provided on the cap 120, so as to form a cavity communicating with the first accommodation cavity 210 of the housing 200 on the cover plate assembly 100, so that the second accommodation cavity 1211 can buffer the high-temperature and high-pressure gas generated when the electrode core undergoes thermal runaway.

[0087] In a specific example, the explosion-proof valve 130 is mainly used to rupture when a large amount of gas is generated inside the battery cell 1000, so that the gas inside the battery cell 1000 can be discharged, to a certain extent, to avoid damage to electronic components caused by electrolyte, high-temperature substances, sparks, etc. ejected inside the battery cell 1000, thereby reducing the safety hazards of electronic components, that is, to a certain extent, to avoid safety problems of the battery cell 1000 due to the inability to discharge the internal pressure in time, and improve the use safety of the battery cell 1000.

[0088] In summary, the cover plate assembly 100 of the battery cell 1000 in the present application can simultaneously ensure the high volumetric energy density and high safety pressure relief performance of the battery cell 1000.

[0089] It should also be noted that the statement that at least one explosion-proof valve 130 is provided on the protrusion 121 means that one explosion-proof valve 130 can be provided on the protrusion 121, or multiple explosion-proof valves 130 can be provided. In the description of the present invention, unless otherwise specified, the meaning of "multiple" is two or more.

[0090] From the above structure, it can be seen that the cover plate assembly 100 of the battery cell 1000 in the embodiment of the present invention is provided with two relatively independent structures (the cover plate body 110 and the cap 120), and a communication port 111 is formed on the cover plate body 110 and a second accommodation cavity 1211 communicating with the communication port 111 is provided on the cap 120, so as to form a cavity communicating with the tab 300 of the battery cell 1000 on the cover plate assembly 100, so that the high-temperature and high-pressure gas generated when the electrode core undergoes thermal runaway can be buffered into the cover plate assembly 100, and avoid the phenomenon that too much gas is stored in the housing 200, resulting in the battery cell 1000 bulging and squeezing adjacent battery cells 1000.

[0091] At the same time, the explosion-proof valve 130 is provided and the explosion-proof valve 130 is arranged on the protrusion 121. While enabling the explosion-proof valve 130 to be set far away from the electrode core, it can also ensure that when the explosion-proof valve 130 is opened for exhaust, a large amount of gas generated inside the battery cell 1000 can be quickly discharged, thereby improving the use safety of the battery cell 1000.

[0092] It can be understood that, compared with the prior art, in the present application, the cover body 110 and the cap 120 cooperate to form a second accommodation cavity 1211 communicating with the tab 300 on the cover assembly 100, and the explosion-proof valve 130 is arranged on the protruding portion 121 formed by the cap 120. While achieving an increase in the volumetric energy density of the battery cell 1000, the battery cell 1000 can also be safely pressure-relieved, thereby improving the safety of use of the battery cell 1000.

[0093] In the description of the present utility model, features defined as "first" and "second" may explicitly or implicitly include one or more of such features, which are used to distinguish and describe features, without order or importance.

[0094] In some embodiments, the cap 120 is formed as a metal part. That is to say, the cap 120 is made of a metal material to ensure the structural strength of the cap 120.

[0095] Optionally, the cover body 110 is formed as a metal part. Here, it means that the cover body 110 can also be made of a metal material to ensure the structural strength of the cover body 110 and at the same time facilitate reducing the difficulty of fixedly connecting the cover body 110 and the cap 120.

[0096] In a specific example, when both the cover body 110 and the cap 120 are made of a metal material, the cover body 110 and the cap 120 can be fixedly connected by welding to ensure the connection strength between the cover body 110 and the cap 120, so that the relative positions of the cover body 110 and the cap 120 are stable, improving the structural stability of the cover assembly 100, and thereby ensuring the working performance of the cover assembly 100.

[0097] It should be noted that Figure 1 shows that the shape of the cap 120 is similar to a rectangle. Of course, in some other embodiments, the shape of the cap 120 can also be formed to be similar to a circle (as Figure 4 shown), an ellipse or a square, etc.

[0098] In addition, the shape of the cover body 110 is not limited to a rectangle, and the shape of the cover body 110 can be adaptively adjusted according to the overall shape of the battery cell 1000, and the present application does not make specific limitations.

[0099] In some embodiments, in combination with Figure 1 、 Figure 2 and Figure 3As shown, the second receiving cavity 1211 is used to receive at least a part of the tab 300 of the battery cell 1000. Here, it means that the battery cell 1000 includes a tab 300, and at least a part of the tab 300 can be assembled in the second receiving cavity 1211 formed by the cap 120. In this way, it can avoid the tab 300 occupying too much space inside the outer shell 200 to a certain extent, thereby improving the space utilization rate of the outer shell 200, so that there is enough space inside the outer shell 200 to set the dressing area of the electrode core, which is convenient for improving the capacity density of the battery cell 1000.

[0100] That is to say, in order to solve the technical problem that the tab 300 in the prior art easily causes waste of space under the cover plate, thereby reducing the space utilization rate inside the outer shell 200 and resulting in a decrease in the volume energy density of the battery cell 1000, the cover plate assembly 100 of the battery cell 1000 in this application is set to include a cover plate body 110 and a cap 120, and at least a part of the cap 120 is set to protrude in a direction away from the communication port 111 to form a second receiving cavity 1211 communicating with the communication port 111 on the cap 120. During the subsequent assembly process of the battery cell 1000, at least a part of the tab 300 can be easily assembled in the protruding portion 121 formed by the cap 120, that is, at least a part of the tab 300 is assembled inside the cover plate assembly 100. In this way, it can avoid the tab 300 occupying too much space inside the outer shell 200 to a certain extent, thereby improving the space utilization rate of the outer shell 200, so that there is enough space inside the outer shell 200 to set the dressing area of the electrode core, which is convenient for improving the capacity density of the battery cell 1000.

[0101] In a specific example, during the assembly process of the tab 300 and the cover plate assembly 100, at least a part of the tab 300 passes through the communication port 111 on the cover plate body 110 and is assembled in the second receiving cavity 1211 to realize using the second receiving cavity 1211 to receive at least a part of the tab 300 of the battery cell 1000.

[0102] In some embodiments, in combination with Figure 1 、 Figure 2 and Figure 3As shown, on the protruding direction of the protruding portion 121, an installation groove 1121 is provided on the first side wall 112 of the cover plate body 110. The cap 120 has an installation flange 122 that cooperates with the installation groove 1121, and the installation flange 122 is limited within the installation groove 1121. Here, it means that on the protruding direction of the protruding portion 121, the cover plate body 110 has a first side wall 112, an installation groove 1121 is provided on the first side wall 112, and an installation flange 122 that can be limited and fitted within the installation groove 1121 is provided on the cap 120. In this way, during the process of fixedly connecting the cap 120 and the cover plate body 110, the installation flange 122 can be limited within the installation groove 1121, and the installation flange 122 and the installation groove 1121 are used for fitting connection to achieve the fixed connection between the cap 120 and the cover plate body 110, thereby reducing the connection difficulty between the cap 120 and the cover plate body 110 and being beneficial to ensuring the connection quality between the cap 120 and the cover plate body 110.

[0103] Wherein, the cooperation between the installation flange 122 and the installation groove 1121 can also perform an initial positioning of the cap 120 during the connection process between the cap 120 and the cover plate body 110, so that the position of the cap 120 relative to the cover plate body 110 is stable, thereby further reducing the connection difficulty between the cap 120 and the cover plate body 110.

[0104] In some embodiments, as shown in combination with Figure 1 、 Figure 2 and Figure 3 the installation groove 1121 is disposed around the outer periphery of the communication port 111 and is in communication with the communication port 111, and the shape of the installation flange 122 matches the shape of the installation groove 1121. Among them, by arranging the installation groove 1121 to surround the outer periphery of the communication port 111 and be in communication with the communication port 111, when the fixed connection between the cap 120 and the cover plate body 110 is achieved by the cooperation between the installation flange 122 and the installation groove 1121, it can be ensured that the second accommodation cavity 1211 on the protruding portion 121 can communicate with the communication port 111, so that at least a part of the tab 300 can pass through the communication port 111 on the cover plate body 110 and be assembled in the second accommodation cavity 1211, which is convenient for improving the energy density of the battery cell 1000.

[0105] Meanwhile, by setting the shape of the installation flange 122 to match the shape of the installation groove 1121, the installation flange 122 can be limited and fitted within the installation groove 1121, and it is beneficial to ensure the contact area between the installation flange 122 and the installation groove 1121, thereby ensuring the connection strength between the installation flange 122 and the installation groove 1121 and ensuring the connection strength between the cap 120 and the cover plate body 110.

[0106] It should be noted that the shape of the installation flange 122 matching the shape of the installation groove 1121 means that the extending direction of the installation flange 122 is the same as that of the installation groove 1121, and the dimensions of the length, width and height of the installation flange 122 are approximately equal to those of the installation groove 1121, so that the installation flange 122 can be limited and fitted in the installation groove 1121 and ensure the contact area between the installation flange 122 and the installation groove 1121.

[0107] In some embodiments, the installation groove 1121 extends away from the communication port 111, and the value range of the extending length of the installation groove 1121 on the same side of the communication port 111 is 0.5 mm to 3 mm. Herein, the extending length of the installation groove 1121 can be understood as Figure 2 L1 shown in. When the extending length L1 is relatively small, the connection strength between the cap 120 and the cover body 110 will be reduced; when the extending length L1 is relatively large, it will not only increase the processing difficulty of the installation flange 122, but also reduce the overall structural strength of the cover body 110.

[0108] Therefore, in the present application, the extending length of the installation groove 1121 extending in the direction on the same side of the communication port 111 is set to 0.5 mm to 3 mm, which not only ensures the connection strength between the cap 120 and the cover body 110, but also facilitates reducing the processing difficulty of the installation flange 122, and ensures the structural strength of the cover body 110, and prolongs the service life of the cover body 110.

[0109] In a specific example, the extending length of the installation groove 1121 extending away from the communication port 111 is 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm or 3 mm, etc.

[0110] In some embodiments, in combination with Figure 6 and Figure 7 as shown, a plurality of explosion-proof valves 130 are provided on the convex portion 121. The cooperation of the plurality of explosion-proof valves 130 can improve the exhaust speed, and further improve the use safety of the battery cell 1000.

[0111] In some embodiments, in combination with Figure 6 and Figure 7 as shown, two explosion-proof valves 130 are provided on the convex portion 121. The cooperation of the two explosion-proof valves 130 can improve the exhaust speed and, to a certain extent, avoid reducing the structural strength of the cap 120 due to the setting of the explosion-proof valves 130, prolong the service life of the cap 120, and reduce the use cost.

[0112] Of course, in some other embodiments, such as Figure 1 and Figure 5As shown, only one explosion-proof valve 130 may also be provided on the convex portion 121.

[0113] In some other examples, three, four, five or more explosion-proof valves 130 may be provided on the convex portion 121.

[0114] In some embodiments, in combination with Figure 1 and Figure 3 As shown, at least one explosion-proof valve 130 is provided on the wall surface of the convex portion 121 facing the communication port 111. Since the gas in the battery cell 1000 mainly enters the second accommodation cavity 1211 through the communication port 111, through the above arrangement, it can be ensured that the gas entering the second accommodation cavity 1211 can effectively flow towards the explosion-proof valve 130. In this way, when the explosion-proof valve 130 is opened, it can be ensured that the gas in the battery cell 1000 can be discharged through the explosion-proof valve 130, improving the use safety of the battery cell 1000.

[0115] At the same time, by arranging the explosion-proof valve 130 on the wall surface of the convex portion 121 facing the communication port 111, it can also be avoided to a certain extent that the liquid or gas ejected from the explosion-proof valve 130 sprays towards the adjacent battery cell 1000, improving the safety performance of the battery pack.

[0116] Of course, in some other embodiments, the explosion-proof valve 130 may also be provided on the outer peripheral wall in the circumferential direction of the convex portion 121. That is to say, it is not limited to arranging the explosion-proof valve 130 on the side wall of the convex portion 121 facing the communication port 111. Through the above arrangement, the gas in the battery cell 1000 can also be discharged by the explosion-proof valve 130 to ensure the use safety of the battery cell 1000.

[0117] In some embodiments, in combination with Figure 1 and Figure 5 As shown, at least one side wall of the convex portion 121 is provided with an installation opening 1212 penetrating therethrough, and an explosion-proof sheet 131 is installed in the installation opening 1212, and the explosion-proof sheet 131 is formed as the explosion-proof valve 130. That is to say, the explosion-proof sheet 131 is installed on at least one side wall of the convex portion 121 through the installation opening 1212 to form the explosion-proof valve 130. In this way, while realizing the improvement of the use safety of the battery cell 1000 by the explosion-proof valve 130, the forming difficulty of the explosion-proof valve 130 can also be reduced.

[0118] In some embodiments, the explosion-proof valve 130 is connected to the installation opening 1212 by laser welding fusion. In this way, while realizing the formation of the explosion-proof valve 130, the matching difficulty between the explosion-proof valve 130 and the convex portion 121 can also be reduced, and the connection strength between the explosion-proof valve 130 and the convex portion 121 can be ensured, improving the position stability of the explosion-proof valve 130, thereby ensuring the working performance of the explosion-proof valve 130.

[0119] It should be noted that after the explosion-proof valve 130 is laser welded, no false welding or welding holes are allowed, and it should have the airtightness required by the design.

[0120] It should also be noted that Figure 1 As shown in the figure, the shape of the explosion-proof valve 130 is similar to an ellipse. In some other embodiments, the shape of the explosion-proof valve 130 can also be designed into any geometric shape such as a circle, rectangle, triangle, trapezoid, ring or sector according to actual manufacturing processes or performance requirements. This application does not make specific restrictions.

[0121] Of course, the shape of the installation port 1212 needs to match the shape of the explosion-proof valve 130. That is to say, the shape of the installation port 1212 can also be formed into any geometric shape such as an ellipse, circle, rectangle, triangle, trapezoid, ring or sector, so as to facilitate the installation of the explosion-proof sheet 131 into the installation port 1212 and ensure the airtightness of the explosion-proof sheet 131.

[0122] In some embodiments, as Figure 6 and Figure 7 shown, a plurality of installation ports 1212 penetrating through it are provided on at least one side wall of the convex portion 121. In this way, a plurality of explosion-proof valves 130 can be arranged on at least one side wall of the convex portion 121. The cooperation of the plurality of explosion-proof valves 130 can improve the exhaust speed, and further improve the use safety of the battery cell 1000.

[0123] Of course, in some other embodiments, installation ports 1212 penetrating through them can also be respectively provided on a plurality of side walls of the convex portion 121 to arrange a plurality of explosion-proof valves 130 on the convex portion 121. In this way, the cooperation of the plurality of explosion-proof valves 130 can also be used to improve the exhaust speed, and further improve the use safety of the battery cell 1000.

[0124] In some embodiments, the area of the side wall provided with the installation port 1212 is S1, and the area of the installation port 1212 is S2. S1 and S2 satisfy: 0.05 ≤ S2 / S1 ≤ 0.95. On the one hand, this can ensure the opening area of the installation port 1212 on the side wall, that is, ensure that the area of the explosion-proof valve 130 itself is appropriate, improve the exhaust performance of the explosion-proof valve 130, and thus increase the use safety of the battery cell 1000 to a certain extent. On the other hand, it can also make the occupied area of the installation port 1212 on the cap 120 more appropriate, and to a certain extent avoid the low structural strength of the cap 120 caused by the opening of the installation port 1212, thereby extending the service life of the cap 120.

[0125] That is to say, in the present application, the area S1 of the side wall provided with the installation opening 1212 and the area S2 of the installation opening 1212 are set to satisfy: 0.05 ≤ S2 / S1 ≤ 0.95. While ensuring that the gas generation amount during the instant gasification of the electrolyte can be smoothly discharged through the explosion-proof valve 130, it can also ensure that the explosion-proof valve 130 occupies an appropriate space on the cap 120, which is beneficial to ensuring the structural strength of the cap 120.

[0126] In a specific example, S2 / S1 = 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9 or 0.95, etc.

[0127] It should be noted that when there are multiple installation openings 1212 penetrating through the same side wall of the protrusion 121, the area S2 of the installation opening 1212 mentioned above is the sum of the areas of the multiple installation openings 1212, so as to avoid to a certain extent the low structural strength of the cap 120 caused by opening multiple installation openings 1212, thereby prolonging the service life of the cap 120.

[0128] In some embodiments, the thickness of the explosion-proof film 131 ranges from 0.1 mm to 1.5 mm. Among them, when the thickness of the explosion-proof film 131 is relatively thin, it will cause the reduction of the structural strength of the explosion-proof film 131, shorten the service life of the explosion-proof film 131, and affect the working performance of the explosion-proof film 131; when the thickness of the explosion-proof film 131 is relatively thick, when the internal pressure of the battery cell 1000 is relatively large, it cannot be ensured that the explosion-proof film 131 can effectively rupture, reducing the use safety of the battery cell 1000.

[0129] Therefore, in the present application, the thickness of the explosion-proof film 131 is set to 0.1 mm to 1.5 mm. In this way, while ensuring the structural strength of the explosion-proof film 131, it can also ensure that when the internal pressure of the battery cell 1000 is relatively large, the explosion-proof film 131 can effectively rupture, so as to facilitate the discharge of the gas in the battery cell 1000 through the explosion-proof film 131 to achieve the function of pressure relief and explosion prevention, so as to improve the use safety of the battery cell 1000.

[0130] In a specific example, the thickness of the explosion-proof film 131 is 0.1 m, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm or 1.5 mm, etc.

[0131] Of course, in some other embodiments, the thickness of the explosion-proof film 131 can also be determined according to the explosion-proof pressure designed for each model of the battery cell 1000.

[0132] In some embodiments, the explosion-proof disc 131 is provided with a first notch (not shown in the figure). The first notch can further ensure that the explosion-proof disc 131 is easier to detonate under the same gas production, so as to facilitate opening the explosion-proof valve 130 when the internal pressure of the battery cell 1000 reaches the upper limit, thereby achieving the purpose of pressure relief, thereby ensuring the working performance of the explosion-proof valve 130.

[0133] The first notch mentioned here may be formed in weak areas of different depths, strengths and rigidities of the explosion-proof plate 131 by laser or other physical or chemical methods.

[0134] In addition, the first notch can be provided on the outer surface of the explosion-proof plate 131 or on the inner surface of the explosion-proof plate 131, as long as it is ensured that when the internal pressure of the battery cell 1000 reaches a preset value, the explosion-proof valve 130 can explode, thereby improving the safety performance of the battery cell 1000.

[0135] In some embodiments, the cover plate assembly 100 further includes a protective sheet (not shown in the figure), which is arranged at the installation opening 1212 and located on the side of the explosion-proof sheet 131 away from the second accommodating chamber 1211. In order to use the protective sheet to protect the explosion-proof sheet 131, it is prevented that external foreign matter falls on the explosion-proof sheet 131 and causes damage to the explosion-proof sheet 131, thereby ensuring the working performance of the explosion-proof sheet 131, reducing the risk of leakage caused by external stress impact or internal and external corrosion, thereby ensuring that the explosion-proof sheet 131 can effectively realize the rapid exhaust and pressure relief of the battery cell 1000, so as to play an explosion-proof role, and to a certain extent solve the technical problem of self-explosion of the battery cell 1000.

[0136] Optionally, the protective sheet is made of materials such as PP (Polypropylene) or PET (Polyethyleneterephthalate) to ensure that the protective sheet can be dissolved when exposed to heat, thereby ensuring that when the explosion-proof sheet 131 is exhausted due to thermal runaway, the protective sheet can be dissolved to facilitate the discharge of gas through the installation port 1212, thereby ensuring the safety of the battery cell 1000.

[0137] In some embodiments, the protective sheet is bonded and fixed to the raised portion 121 so that the protective sheet can be placed at the mounting port 1212 and a fixed connection between the protective sheet and the raised portion 121 can be achieved. At the same time, during thermal runaway exhaust, heat can be used to dissolve the connection between the protective sheet and the raised portion 121 to facilitate gas discharge, thereby further ensuring the safety of the battery cell 1000.

[0138] In some embodiments, the thickness of the protection sheet ranges from 0.1 mm to 1.5 mm. When the thickness of the protection sheet is designed within the above range, the working performance of the protection sheet will be further improved, enabling the protection sheet to effectively protect the explosion-proof sheet 131, which is conducive to the dissolution of the protection sheet when heated, thereby enhancing the exhaust effect.

[0139] Therefore, in this application, the thickness range of the protection sheet is set to 0.1 mm to 1.5 mm. In this way, while ensuring the working performance of the protection sheet and ensuring that the explosion-proof sheet 131 can be effectively protected by the protection sheet, the protection sheet can also dissolve after being heated, facilitating the discharge of gas.

[0140] In a specific example, the thickness of the protection sheet is 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, or 1.5 mm, etc.

[0141] In some embodiments, in combination Figure 8 and Figure 9 As shown, a second notch 1213 is provided on at least one side wall of the convex portion 121, and the second notch 1213 forms an explosion-proof valve 130. That is to say, it is not limited to setting the installation opening 1212 and the explosion-proof sheet 131 on the convex portion 121. A second notch 1213 can also be provided on at least one side wall of the convex portion 121. By using the second notch 1213, the structural strength of a part of the structure of the convex portion 121 is reduced, so as to ensure that when the internal pressure of the battery cell 1000 is relatively large, a part of the structure of the convex portion 121 can effectively rupture, thereby facilitating the discharge of the gas in the battery cell 1000 to achieve the function of pressure relief and explosion protection, and ensuring the safety performance of the battery cell 1000.

[0142] Among them, the second notch 1213 mentioned here can be formed in weak areas of different depths, strengths, and stiffnesses on the convex portion 121 by laser or other physical methods, chemical methods, etc.

[0143] In addition, the second notch 1213 can be provided on the outer surface of the convex portion 121 or on the inner surface of the convex portion 121, as long as it is ensured that the explosion-proof valve 130 can burst when the internal pressure of the battery cell 1000 reaches a preset value, thereby improving the safety performance of the battery cell 1000.

[0144] In some embodiments, in combination Figures 8 - 13As shown, the second notch 1213 includes at least one arc-shaped notch and / or at least one straight notch. That is to say, the second notch 1213 includes at least one arc-shaped notch; or, the second notch 1213 includes at least one straight notch; or, the second notch 1213 includes at least one arc-shaped notch and at least one straight notch, that is, the second notch 1213 can be composed of at least one arc-shaped notch and at least one straight notch.

[0145] In some embodiments, as Figure 8 and Figure 9 shown, the second notch 1213 includes two arc-shaped notches.

[0146] Of course, in some other embodiments, the second notch 1213 may also include one arc-shaped notch; or, the second notch 1213 is composed of one arc-shaped notch and at least one straight notch.

[0147] In some other embodiments, in combination with Figure 10 , Figure 11 , Figure 12 and Figure 13 shown, the second notch 1213 includes a straight notch, and the second notch 1213 can also be composed of multiple straight notches. The multiple straight notches can form a closed figure or an open figure.

[0148] Among them, Figure 10 , Figure 11 and Figure 12 respectively show examples in which the second notch 1213 is composed of multiple straight notches to form an open figure, Figure 13 shows an example in which the second notch 1213 is composed of multiple straight notches to form a closed figure.

[0149] Among them, when the second notch 1213 is composed of multiple straight notches to form a closed figure, the overall shape of the second notch 1213 after forming can also be triangular (as Figure 13 shown), rectangular or trapezoidal, etc.; when the second notch 1213 is composed of multiple straight notches to form an open figure, the overall shape of the second notch 1213 after forming can be referred to Figure 10 , Figure 11 and Figure 12 .

[0150] In some embodiments, the thickness of the side wall provided with the second notch 1213 is greater than 0.2 mm. Among them, the thickness of the side wall provided with the second notch 1213 mentioned here can be understood as L2 shown in Figure 14 . By limiting the above thickness, the structural strength of the convex part 121 can be guaranteed to a certain extent, and further, the convex part 121 can be prevented from bursting prematurely to a certain extent, so as to ensure the working performance of the convex part 121.

[0151] In some embodiments, such as Figure 15 and Figure 16 shown, a plurality of second notches 1213 are provided on at least one side wall of the convex portion 121. In this way, a plurality of explosion-proof valves 130 can be arranged on at least one side wall of the convex portion 121, and the cooperation of the plurality of explosion-proof valves 130 can improve the exhaust speed, thereby improving the use safety of the battery cell 1000.

[0152] Of course, in some other embodiments, second notches 1213 can also be respectively provided on a plurality of side walls of the convex portion 121 to realize the arrangement of a plurality of explosion-proof valves 130 on the convex portion 121. In this way, the cooperation of the plurality of explosion-proof valves 130 can also be used to improve the exhaust speed, thereby improving the use safety of the battery cell 1000.

[0153] In some embodiments, the area of the side wall provided with the second notch 1213 is S1, and the covered area of the projection of the second notch 1213 on the first plane is S3. S1 and S3 satisfy: 0.05 ≤ S3 / S1 ≤ 0.95, and the first plane is perpendicular to the thickness direction of the cover body 110. On the one hand, this can ensure the area of the second notch 1213, that is, ensure that the area of the explosion-proof valve 130 itself is appropriate, improve the exhaust performance of the explosion-proof valve 130, and thus increase the use safety of the battery cell 1000 to a certain extent. On the other hand, it can also make the occupied area of the second notch 1213 on the cap 120 more appropriate, and to a certain extent avoid the low structural strength of the cap 120 caused by the opening of the second notch 1213, thereby prolonging the service life of the cap 120.

[0154] That is to say, in the present application, the area S1 of the side wall provided with the second notch 1213 and the covered area S3 of the projection of the second notch 1213 on the first plane are set to satisfy: 0.05 ≤ S2 / S1 ≤ 0.95. While ensuring that the gas generation amount during the instant gasification of the electrolyte can be smoothly discharged through the explosion-proof valve 130, it can also ensure that the explosion-proof valve 130 occupies an appropriate space on the cap 120, which is beneficial to ensuring the structural strength of the cap 120.

[0155] In a specific example, S2 / S1 = 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9 or 0.95, etc.

[0156] It should be noted that when multiple second notches 1213 are provided on the same side wall of the convex portion 121, the covering area S3 of the projections of the above-mentioned second notches 1213 on the first plane is the sum of the covering areas of the projections of the multiple second notches 1213, so as to avoid to a certain extent the low structural strength of the cap 120 caused by opening multiple second notches 1213, thereby extending the service life of the cap 120.

[0157] In some embodiments, as Figure 3 shown, the value range of the thickness W of the cap 120 is 0.3 mm to 5 mm. Among them, when the thickness W of the cap 120 is relatively thin, the structural strength of the cap 120 will be reduced; when the thickness W of the cap 120 is relatively thick, it will not only increase the manufacturing cost of the cap 120, but also increase the weight of the cap 120, which is not conducive to realizing the lightweight setting of the battery cell 1000.

[0158] Therefore, in this application, the thickness W of the cap 120 is set to 0.3 mm to 5 mm, which can not only ensure the structural strength of the cap 120, but also reduce the manufacturing cost of the cap 120 and realize the lightweight setting of the battery cell 1000.

[0159] In a specific example, the thickness W of the cap 120 is 0.3 mm, 0.4 mm, 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm or 5 mm.

[0160] Optionally, as Figure 3 shown, the value range of the protruding height H1 of the convex portion 121 is 2 mm to 50 mm. Among them, when the protruding height H1 of the convex portion 121 is relatively low, the accommodating space of the second accommodating cavity 1211 will be reduced, and it cannot be ensured that at least part of the tab 300 can be effectively assembled in the cover plate assembly 100, which is not conducive to improving the energy density of the battery cell 1000; when the protruding height H1 of the convex portion 121 is relatively high, the size of the cover plate assembly 100 will be increased, and then the size of the battery cell 1000 will be increased.

[0161] Therefore, in this application, the value range of the protruding height H1 of the convex portion 121 is 2 mm to 50 mm, which can ensure the accommodating space of the second accommodating cavity 1211 and is also convenient for reducing the size of the battery cell 1000, thereby improving the energy density of the battery cell 1000.

[0162] In some embodiments, the value range of the protruding height H1 of the convex portion 121 is 2 mm to 10 mm. To further optimize the size of the convex portion 121.

[0163] In a specific example, the protruding height H1 of the protruding portion 121 is 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm or 10 mm.

[0164] In some embodiments, on the first plane, the projected area of the communication port 111 is S1, and the projected area of the cover plate body 110 excluding the communication port 111 is S4. S1 and S4 satisfy: 0.1 ≤ S1 / S4 ≤ 3. The first plane is perpendicular to the thickness direction of the cover plate body 110. Among them, when the area of the communication port 111 is relatively small with respect to the area of the cover plate body 110, it is not conducive to assembling at least part of the tab 300 into the cover plate assembly 100. When the area of the communication port 111 is relatively large with respect to the area of the cover plate body 110, the structural strength of the cover plate body 110 will be reduced.

[0165] Among them, in this application, the projected area S1 of the communication port 111 and the projected area S4 of the cover plate body 110 excluding the communication port 111 are set to satisfy: 0.1 ≤ S1 / S4 ≤ 3. While ensuring that at least part of the tab 300 can be assembled into the cover plate assembly 100, the structural strength of the cover plate body 110 can also be guaranteed, thereby ensuring the working performance of the cover plate assembly 100.

[0166] In a specific example, S1 / S4 = 0.1, 0.5, 1, 1.5, 2, 2.5 or 3, etc.

[0167] In some embodiments, the opening pressure D of the explosion-proof valve 130 ranges from 0.15 Mpa to 3 Mpa to ensure the working performance of the explosion-proof valve 130.

[0168] In some embodiments, as Figure 1 shown, the cover plate assembly 100 further includes a terminal assembly 140, and the terminal assembly 140 is arranged on the cover plate body 110. That is to say, in addition to setting the communication port 111 on the cover plate body 110, the terminal assembly 140 is also set. Arranging the terminal assembly 140 on the cover plate body 110 can realize supporting the terminal assembly 140 by the cover plate body 110 to improve the position stability of the terminal assembly 140, thereby ensuring the working performance of the terminal assembly 140.

[0169] In some embodiments, the battery cell 1000 has a core, and the terminal assembly 140 is adapted to be electrically connected to the core so as to lead out the current of the core by using the terminal assembly 140 to ensure the working performance of the core.

[0170] In some embodiments, an assembly port is provided on the cover plate body 110, and the pole column assembly 140 is disposed in the assembly port, so that the pole column assembly 140 can be arranged on the cover plate body 110, facilitating the use of the cover plate body 110 to support the pole column assembly 140, improving the position stability of the pole column assembly 140, and reducing the matching difficulty between the pole column assembly 140 and the cover plate body 110.

[0171] It should be noted that by disposing the pole column assembly 140 on the cover plate body 110, the space occupied by the pole column assembly 140 on the cap 120 can be avoided. While reducing the molding difficulty of the cap 120, it can also ensure that there is sufficient space on the cap 120 to arrange the pole column assembly 140.

[0172] Optionally, the protruding height H1 of the protruding portion 121 and the height H2 of the pole column assembly 140 protruding from the cover plate body 110 satisfy: -5 mm ≤ H1 - H2 ≤ 5 mm. This means that in the protruding direction of the protruding portion 121, the protruding portion 121 can protrude from the pole column assembly 140, be flush with the pole column assembly 140, or be lower than the pole column assembly 140. Among them, when the protruding portion 121 protrudes from the pole column assembly 140, the height of the protruding portion 121 protruding from the pole column assembly 140 should not be too high, so as to avoid excessively increasing the size of the battery cell 1000 to a certain extent, thus facilitating the guarantee of the size of the battery cell 1000; when the protruding portion 121 is lower than the pole column assembly 140, the protruding portion 121 should not be too low to ensure the accommodation space of the second accommodation cavity 1211, ensuring that at least part of the tab 300 can be effectively assembled in the cover plate assembly 100, thereby improving the energy density of the battery cell 1000.

[0173] In some embodiments, H1 - H2 = -5 mm, -4 mm, -3 mm, -2 mm, -1 mm, 0 mm, 1 mm, 2 mm, 3 mm, 4 mm or 5 mm, etc.

[0174] In some embodiments, the cover plate assembly 100 further includes a liquid injection hole (not shown in the figure), and the liquid injection hole is provided on the cover plate body 110 and / or the protruding portion 121, and the liquid injection hole communicates with the first accommodation cavity 210. This means that the liquid injection hole can be provided on the cover plate body 110, or on the protruding portion 121, or liquid injection holes can be provided on both the cover plate body 110 and the protruding portion 121. By providing the liquid injection hole, it is convenient to inject liquid into the battery cell 1000 through the cover plate assembly 100 after the battery cell 1000 is assembled, reducing the liquid injection difficulty while ensuring the working performance of the battery cell 1000.

[0175] In some embodiments, the liquid injection hole communicates with the second accommodation cavity 1211. By setting the liquid injection hole to communicate with the second accommodation cavity 1211, part of the electrolyte can be stored in the second accommodation cavity 1211 during the liquid injection process for faster liquid injection and reduced number of liquid injection times.

[0176] Next, the battery housing 600 of the embodiments of the present invention will be described with reference to the accompanying drawings of the specification.

[0177] As Figure 1 shown, a battery housing 600 according to an embodiment of the present invention includes: a housing 200 and a cover assembly 100.

[0178] Among them, as combined Figure 1 and Figure 3 shown, a first accommodation cavity 210 having an opening 211 is formed inside the housing 200, and a pole core is adapted to be placed inside the first accommodation cavity 210. Thereby, the pole core is arranged inside the housing 200, which is convenient for protecting the pole core by the housing 200, prolonging the service life of the pole core, and improving the use safety of the pole core.

[0179] As Figure 1 shown, the cover assembly 100 is the aforementioned cover assembly 100, and the specific structure of the cover assembly 100 will not be specifically described herein. The cover assembly 100 is arranged at the opening 211.

[0180] From the above structure, it can be seen that for the battery housing 600 of the embodiments of the present invention, by adopting the aforementioned cover assembly 100, when the battery housing 600 is applied to the battery cell 1000, while achieving a high volumetric energy density of the battery cell 1000, the use safety of the battery cell 1000 can be ensured to a certain extent.

[0181] In some embodiments, the housing 200 is formed by stamping or welding, and the material of the housing 200 is aluminum or steel, etc.

[0182] Next, the battery cell 1000 of the embodiments of the present invention will be described with reference to the accompanying drawings of the specification.

[0183] As Figure 1 shown, a battery cell 1000 according to an embodiment of the present invention includes: a pole core and a cover assembly 100 or a battery housing 600.

[0184] At least part of the pole ear 300 of the pole core is arranged inside the second accommodation cavity 1211.

[0185] From the above structure, it can be seen that for the battery cell 1000 of the embodiments of the present invention, by adopting the aforementioned cover assembly 100, while achieving a high volumetric energy density of the battery cell 1000, the use safety of the battery cell 1000 can be ensured to a certain extent.

[0186] In a specific example, during the assembly of the battery cell 1000, first, the tab 300 is led out to the outside of the housing 200 through the communication port 111 on the surface of the cover body 110 for welding, and then the cap 120 is fixedly connected to the cover body 110 to assemble at least a part of the tab 300 in the second accommodation cavity 1211.

[0187] In some embodiments, as Figure 3 shown, the tab 300 and the cap 120 are arranged at intervals, and the minimum distance between the tab 300 and the cap 120 ranges from 1 mm to 10 mm. Herein, the minimum distance between the tab 300 and the cap 120 can be understood as Figure 3 L3 shown in

[0188] In some embodiments, as Figure 3 shown, the battery cell 1000 further includes an insulating member 500, and the insulating member 500 is disposed between the cover body 110 and the electrode core to avoid electrical connection between the cover body 110 and the electrode core to a certain extent, further ensuring the use safety of the battery cell 1000.

[0189] Next, the battery pack according to the embodiment of the present invention will be described.

[0190] A battery pack according to an embodiment of the present invention includes: a plurality of battery cells 1000.

[0191] Among them, the battery cell 1000 is the aforementioned battery cell 1000, and the specific structure of the battery cell 1000 will not be specifically described herein.

[0192] From the above structure, it can be seen that for the battery pack according to the embodiment of the present invention, by adopting the aforementioned battery cell 1000, it is beneficial to improve the energy density of the battery pack and ensure the use safety of the battery pack.

[0193] In some embodiments, the battery pack includes a housing assembly, and a plurality of battery cells 1000 are disposed in the housing assembly to form a battery pack. Among them, the housing assembly is mainly used to protect and support the plurality of battery cells 1000 to improve the position stability of the battery cells 1000, ensure the working performance of the battery cells 1000, and at the same time, it can also extend the service life of the battery cells 1000 and improve the use safety of the battery cells 1000 to further ensure the working performance of the battery pack.

[0194] Next, the electrical device according to the embodiment of the present invention will be described.

[0195] An electrical device according to an embodiment of the present utility model includes: a battery pack.

[0196] Wherein, the battery pack is the aforementioned battery pack, and the specific structure of the battery pack will not be specifically described herein.

[0197] From the above structure, it can be seen that for the electrical device according to the embodiment of the present utility model, by adopting the aforementioned battery pack, it is beneficial to improve the working performance of the electrical device and ensure the use safety of the electrical device.

[0198] It should be noted that the electrical device mentioned here can be, but is not limited to, mobile phones, tablets, laptop computers, electric toys, electric tools, battery cars, electric vehicles, ships, spacecraft, etc.

[0199] Among them, the electric toy can include fixed or mobile electric toys, such as game consoles, electric vehicle toys, electric ship toys, and electric aircraft toys, etc.; the spacecraft can include airplanes, rockets, space shuttles, and spaceships, etc.; the electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools, and electric tools for railways, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact electric drills, concrete vibrators, and electric planers, etc.

[0200] It should also be noted that when the electrical device is formed into a vehicle such as a battery car or an electric vehicle, by adopting the aforementioned battery pack, the cruising range of the vehicle can be effectively improved, thereby improving the driving experience.

[0201] In the description of the present utility model, it should be noted that unless otherwise clearly specified and limited, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0202] Figure 6 and Figure 7 Two mounting openings 1212 are shown in [figure] and [figure] for illustrative purposes, but those of ordinary skill in the art will clearly understand that the above solution can be applied to a technical solution with three or more mounting openings 1212, which also falls within the protection scope of the present utility model.

[0203] For those of ordinary skill in the art, the cover assembly 100, battery housing 600, battery cell 1000, battery pack, and other components of the electrical device according to the embodiment of the present utility model are all known, and will not be described in detail here.

[0204] In the description of this specification, the descriptions referring to terms such as "embodiment", "example", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in a suitable manner in any one or more embodiments or examples.

[0205] Although the embodiments of the present utility model have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present utility model, and the scope of the present utility model is defined by the claims and their equivalents.

Claims

1. A cover plate assembly for a battery cell, characterized in that: include: A cover body, the cover body is suitable for connecting to the shell of the battery cell, the cover body is provided with a communication port running through it, the communication port is suitable for connecting to a first accommodating cavity of the shell, and the first accommodating cavity is suitable for placing a pole core; A cover cap, wherein the cover cap is arranged on the cover plate body and faces the connecting port, the cover cap is fixedly connected to the cover plate body, at least a portion of the cover cap protrudes in a direction away from the connecting port to form a protrusion, and a side of the protrusion facing the connecting port forms a second accommodating chamber connected to the connecting port, the second accommodating chamber is used for caching gas, at least one explosion-proof valve is arranged on the protrusion, and the explosion-proof valve is configured to break after a set pressure is reached inside the pole core to connect the second accommodating chamber.

2. The cover plate assembly of the battery cell according to claim 1, characterized in that: The second accommodation cavity is used to accommodate at least a portion of the tab of the battery cell.

3. The cover plate assembly of the battery cell according to claim 1, characterized in that: A plurality of explosion-proof valves are arranged on the protruding portion.

4. The cover plate assembly of the battery cell according to claim 1, characterized in that: At least one explosion-proof valve is arranged on the wall surface of the protruding portion facing the communicating port.

5. The cover plate assembly of the battery cell according to claim 1, characterized in that: At least one side wall of the protruding portion is provided with an installation opening penetrating therethrough, and an explosion-proof disk is installed in the installation opening, and the explosion-proof disk forms the explosion-proof valve.

6. The cover plate assembly of the battery cell according to claim 5, characterized in that: The area of ​​the side wall provided with the mounting opening is S1, the area of ​​the mounting opening is S2, and S1 and S2 satisfy: 0.05≤S2 / S1≤0.

95.

7. The cover plate assembly of the battery cell according to claim 5, characterized in that: The bursting disk is provided with a first notch.

8. The cover plate assembly of the battery cell according to claim 5, characterized in that: It also includes a protection sheet, which is arranged at the installation opening and located on a side of the explosion-proof sheet away from the second accommodating cavity.

9. The cover plate assembly of the battery cell according to claim 8, characterized in that: The thickness of the protection sheet ranges from 0.1 mm to 1.5 mm.

10. The cover plate assembly of the battery cell according to claim 1, characterized in that: A second notch is provided on at least one side wall of the protruding portion, and the second notch is formed as the explosion-proof valve.

11. The cover plate assembly of the battery cell according to claim 10, characterized in that: The second notch includes at least one arc-shaped notch and / or at least one straight-line notch.

12. The cover plate assembly of the battery cell according to claim 10, characterized in that: The thickness of the side wall provided with the second notch is greater than 0.2 mm.

13. The cover plate assembly of the battery cell according to claim 10, characterized in that: The area of ​​the side wall provided with the second notch is S1, the coverage area of ​​the projection of the second notch on the first plane is S3, S1 and S3 satisfy: 0.05≤S3 / S1≤0.95, and the first plane is perpendicular to the thickness direction of the cover plate body.

14. The cover plate assembly of the battery cell according to claim 1, characterized in that: The thickness W of the cap ranges from 0.3 mm to 5 mm; And / or, the protrusion height H1 of the protrusion portion ranges from 2 mm to 50 mm.

15. The cover plate assembly of the battery cell according to claim 1, characterized in that: On the first plane, the projection area of ​​the communication port is S1, the projection area of ​​the cover body excluding the communication port is S4, S1 and S4 satisfy: 0.1≤S1 / S4≤3, and the first plane is perpendicular to the thickness direction of the cover body.

16. The cover plate assembly of the battery cell according to claim 1, characterized in that: It also includes a pole assembly, wherein the pole assembly is arranged on the cover plate body; A protruding height H1 of the protruding portion and a height H2 of the pole assembly protruding from the cover plate body satisfy: -5mm≤H1-H2≤5mm.

17. The cover plate assembly of a battery cell according to any one of claims 1 to 16, characterized in that: It also includes a liquid injection hole, which is arranged on the cover body and / or the protruding portion, and is connected to the first accommodating cavity.

18. The cover plate assembly of a battery cell according to any one of claims 1 to 16, characterized in that: In the protruding direction toward the protruding portion, the first side wall of the cover plate body is provided with a mounting groove, and the cover cap has a mounting flange matched with the mounting groove, and the mounting flange is limited in the mounting groove.

19. The cover plate assembly of the battery cell according to claim 18, characterized in that: The installation groove is arranged around the outer periphery of the communication port and is communicated with the communication port, and the shape of the installation flange matches the shape of the installation groove.

20. The cover plate assembly of the battery cell according to claim 18, characterized in that: The mounting groove extends in a direction away from the communicating port, and the extending length of the mounting groove on the same side of the communicating port ranges from 0.5 mm to 3 mm.

21. A battery casing, characterized in that: include: A shell, wherein a first accommodating cavity having an opening is formed in the shell, and the first accommodating cavity is suitable for accommodating the pole core; A cover plate assembly, wherein the cover plate assembly is the cover plate assembly according to any one of claims 1-20, and the cover plate assembly is arranged at the opening.

22. A battery cell, characterized in that: It comprises a pole core and a cover plate assembly according to any one of claims 1 to 20 or a battery casing according to any one of claims 21, wherein at least a portion of the pole lug of the pole core is disposed in the second accommodating cavity.

23. The battery cell according to claim 22, characterized in that: The pole lug and the cap are spaced apart, and the minimum distance between the pole lug and the cap ranges from 1 mm to 50 mm.

24. A battery pack, characterized in that: Comprising a plurality of battery cells according to claim 22 or 23.

25. An electrical device, characterized in that: Comprising a battery pack according to claim 24.

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