Battery cell and battery pack

Abstract

A battery cell and a battery pack. The battery cell comprises a casing (10), a first cover plate (20), a pressure relief member (30), a blocking member (40), and an insulating protection member (50). A pressure relief channel is provided on the first cover plate (20); a support boss (21) is provided on the side of the first cover plate (20) facing the interior of the battery cell; the pressure relief member (30) is mounted on the pressure relief channel; the blocking member (40) is arranged on the support boss (21); the blocking member (40) and the pressure relief channel are arranged opposite each other and spaced apart from each other; a first pressure relief hole (41) is provided in the blocking member (40); a second pressure relief hole (51) is provided in the insulating protection member (50); and the effective opening area of the pressure relief member (30) is defined as S1, the total area of the first pressure relief hole (41) is defined as S2, and the total area of the second pressure relief hole (51) is defined as S3, satisfying 1.22≤S2 / S1≤1.3, and 1.6≤S3 / S2≤2.

Description

Battery cells and battery packs

[0001] Cross-reference of related applications

[0002] This application claims priority to Chinese Patent Application No. CN202411916050.4, filed on December 24, 2024, entitled "Battery Cell and Battery Pack", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of battery technology, and in particular to a battery cell and battery pack. Background Technology

[0004] Lithium-ion batteries have become the most widely used rechargeable batteries due to their advantages such as high energy density, good cycle performance, high operating voltage, and no memory effect. As power batteries, they are widely used in electric vehicles and energy storage. The performance and safety requirements of lithium-ion batteries are becoming increasingly stringent.

[0005] As shown in Figure 1, the long-cell lithium-ion battery integrates an explosion-proof valve 2, a positive or negative electrode post 3, and a lower plastic 4. The cover plate 1 is welded to the shell 5 to form a sealed space to protect the electrode assembly 6. The bare cell insulating film 7 covers the electrode assembly 6 and is then heat-fused to the lower plastic 4 on the cover plate 1. The explosion-proof valve 2 can open when the battery experiences thermal runaway due to an internal short circuit, so as to directionally discharge the high-temperature and high-pressure gas inside the cell, thereby improving the battery safety performance.

[0006] Because the electrode assembly in the battery cell relies on the lower plastic and the bare cell insulation film for insulation and fixation, and because these insulation materials are usually made of PP (polypropylene), the high temperature resistance is generally about 150°C, which is lower than the temperature at which thermal runaway occurs. During thermal runaway, at least part of the insulation material melts, which increases the gap between the electrode assembly and the cover plate and shell. When high temperature and high pressure gas is vented in the direction of the explosion-proof valve, it can easily cause the electrode assembly to move towards the direction of the explosion-proof valve, thereby blocking or blocking the explosion-proof valve, resulting in the inability to vent in time, and thus affecting the safety performance of the battery cell.

[0007] Application content

[0008] In view of this, the purpose of this application is to provide a battery cell and battery pack to solve the problem that the insulating components inside the battery cell are prone to melting during thermal runaway, the gap between the electrode assembly and the cover plate and the shell increases, and the electrode assembly will move with the high temperature and high pressure airflow, blocking or blocking the explosion-proof valve on the cover plate, resulting in the inability to vent in time, thereby reducing the safety performance of the battery cell.

[0009] In a first aspect, this application provides a battery cell, wherein the battery cell comprises:

[0010] case;

[0011] A first cover plate is installed on the housing. A pressure relief channel is provided on the first cover plate, and a support protrusion is provided on the side of the first cover plate facing the inside of the cell.

[0012] Pressure relief components are installed in the pressure relief channel;

[0013] A baffle is provided on the support boss, the baffle and the pressure relief channel are spaced apart from each other, and the baffle is provided with a first pressure relief hole;

[0014] An insulating protective component is provided on the side of the partition facing the inside of the cell, and a second pressure relief hole is provided on the insulating protective component;

[0015] When the pressure relief component is opened, the connected area between the inside and outside of the battery cell at the pressure relief channel is the effective opening area of ​​the pressure relief component, which is S1, and the unit is mm. 2 The total area of ​​the first pressure relief hole is S2, in mm. 2 The total area of ​​the second pressure relief hole is S3, in mm. 2 ; 1.22≤S2 / S1≤1.3, 1.6≤S3 / S2≤2.

[0016] Beneficial effects: The first cover plate is installed on the housing and has a pressure relief channel, and the pressure relief component is installed in the pressure relief channel; a support boss is provided on the side of the first cover plate facing the inside of the cell, and a baffle is provided on the support boss. The baffle and the pressure relief channel are spaced apart from each other, and the baffle has a first pressure relief hole. In this way, when the cell experiences thermal runaway, even if the insulating components inside the cell melt and the electrode group moves towards the pressure relief component with the high temperature and high pressure airflow, the baffle can prevent the electrode group from moving further towards the pressure relief component, thereby meeting the exhaust requirements. The insulating protective component is located on the side of the partition facing the inside of the cell. The insulating protective component has a second pressure relief hole. At low temperatures, the insulating protective component has sufficient strength to meet the venting requirements, ensuring smooth venting and that the venting rate is not affected. When the insulating components inside the cell melt and fail, causing the electrode assembly to move towards the pressure relief component under the impact of high temperature and high pressure gas, the partition can support the electrode assembly to ensure venting requirements while also effectively preventing combustibles inside the cell from splashing out through the pressure relief component, thereby improving the safety performance of the cell and battery pack.

[0017] In one alternative embodiment, the partition is formed as a plate-like structure and is arranged parallel to the first cover plate;

[0018] And / or, the thickness of the partition is t, where 1.1mm≤t≤1.5mm is the thickness of the ternary lithium battery cell, and 0.8mm≤t≤1.1mm is the thickness of the lithium iron phosphate battery cell.

[0019] In one optional embodiment, the partition is disposed on the side of the support boss away from the first cover plate, and the distance between the partition and the first cover plate is H, where 1mm≤H≤2mm.

[0020] In one optional embodiment, multiple first pressure relief holes are provided, and the multiple first pressure relief holes are arranged in an array on the partition.

[0021] Multiple second pressure relief holes are provided, and the multiple second pressure relief holes are arranged in an array on the insulating protective component.

[0022] In one optional embodiment, the second pressure relief hole includes a first through hole and a second through hole; along the axial direction of the second pressure relief hole, the projection of the first through hole facing the outside of the battery cell is projected onto the partition, and the projection of the second through hole facing the outside of the battery cell is projected onto the first cover plate.

[0023] In one optional embodiment, the partition is welded to the support boss; on the surface of the first cover plate, the minimum distance between the support boss and the pressure relief member is L, where L≥4mm.

[0024] In one alternative embodiment, the projection of the baffle onto the first cover plate covers the pressure relief channel.

[0025] In one alternative implementation, it further includes:

[0026] The electrode assembly is disposed inside the housing. The insulating protective element is disposed between the first cover plate and the electrode assembly. The electrode assembly is provided with protruding electrode tabs, which do not protrude in the direction close to the insulating protective element.

[0027] In one alternative implementation, it further includes:

[0028] A second cover plate is installed on the housing, and the second cover plate is provided with an installation hole and a liquid injection hole;

[0029] The pole is disposed in the mounting hole.

[0030] Secondly, this application provides a battery pack including the battery cells described in any of the above technical solutions. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0032] Figure 1. Exploded view of the structure of a battery cell in the prior art;

[0033] Figure 2 is an exploded view of the battery cell provided in an embodiment of this application;

[0034] Figure 3 is an exploded view of the structure of the first cover plate, the partition, and the insulating protection component in the battery cell provided in the embodiment of this application.

[0035] Icons: 10-Shell; 20-First cover plate; 21-Support boss; 30-Pressure relief component; 31-Protective patch; 40-Blocking component; 41-First pressure relief hole; 42-Vent passage; 50-Insulation protection component; 51-Second pressure relief hole; 511-First through hole; 512-Second through hole; 60-Second cover plate; 61-Injection hole; 62-Plastic component; 70-Electrode assembly; 71-Electrode tab; 72-Insulating film; 80-Electrode post; 1-Cover plate; 2-Explosion-proof valve; 3-Positive or negative electrode post; 4-Lower plastic; 5-Shell; 6-Electrode assembly; 7-Bare cell insulating film. Detailed Implementation

[0036] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein 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 with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0037] The following disclosure provides numerous different embodiments or examples for implementing various structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, various specific examples of processes and materials are provided in this application; however, those skilled in the art will recognize the applicability of other processes and / or the use of other materials.

[0038] According to a first aspect of this application, a battery cell is provided, which specifically includes a housing 10, a first cover plate 20, a pressure relief component 30, a partition component 40, and an insulating protection component 50.

[0039] The specific structure of the battery cell according to this embodiment, as described above, will be described below.

[0040] In this embodiment, as shown in Figure 2, a cavity is provided inside the housing 10. The electrode assembly 70 is disposed in the cavity inside the housing 10. The electrode assembly 70 can be formed by stacking or winding electrode sheets. The electrode assembly 70 is provided with protruding tabs 71, including a positive tab 71 and a negative tab 71. A first cover plate 20 is installed on the housing 10. The first cover plate 20 is formed into a plate-like structure, such as a rectangular plate-like structure. A pressure relief channel is provided on the first cover plate 20. The pressure relief channel is formed into a channel that penetrates the first cover plate 20 in the thickness direction to realize the connection between the inside and outside of the battery cell. A pressure relief component 30 is installed in the pressure relief channel. The pressure relief component 30 can be an explosion-proof valve. When the pressure inside the battery cell reaches the opening pressure of the pressure relief component 30, the pressure relief component 30 opens, so that the inside and outside of the battery cell are connected, thereby facilitating the discharge of gas inside the battery cell.

[0041] In this embodiment, as shown in Figure 3, a support boss 21 is provided on the side of the first cover plate 20 facing the inside of the battery cell. The support boss 21 can be formed by stamping on the side of the first cover plate 20 facing the outside of the battery cell. A baffle 40 is provided on the support boss 21. In the thickness direction of the first cover plate 20, the baffle 40 and the pressure relief channel are spaced apart from each other, and a first pressure relief hole 41 is provided on the baffle 40. The first pressure relief hole 41 is a through hole penetrating the baffle 40. In this way, when thermal runaway occurs in the battery cell, even if the insulating components inside the battery cell melt and the electrode assembly 70 moves towards the pressure relief component 30 with the high temperature and high pressure airflow, the baffle 40 can prevent the electrode assembly 70 from moving further towards the pressure relief component 30, thereby meeting the venting requirements. It should be noted that in this embodiment, the insulating components inside the battery cell are the insulating protective component 50, the insulating film 72, or the plastic component 62 described below.

[0042] In this embodiment, as shown in Figures 2 and 3, the insulating protective member 50 is disposed on the side of the partition member 40 facing the inside of the cell. The insulating protective member 50 is disposed between the first cover plate 20 and the electrode group 70, and is used to separate the electrode post 80 and the first cover plate 20 on which the partition member 40 is installed, so as to form an insulating protection for the first cover plate 20. The insulating protective member 50 is provided with a second pressure relief hole 51, which is a through hole penetrating the insulating protective member 50.

[0043] In a preferred embodiment, as shown in Figures 2 and 3, a plurality of first pressure relief holes 41 are provided, and the plurality of first pressure relief holes 41 are arranged in an array on the partition 40. The first pressure relief holes 41 can be arranged in a rectangular, circular or shape similar to the outer edge contour of the pressure relief member 30. A plurality of second pressure relief holes 51 are provided, and the plurality of second pressure relief holes 51 are arranged in an array on the insulating protective member 50.

[0044] Further, as shown in Figure 3, the second pressure relief hole 51 includes a first through hole 511 and a second through hole 512. Along the axial direction of the second pressure relief hole 51, the projection of the first through hole 511 facing the outside of the battery cell is projected onto the partition 40, such that the arrangement area of ​​the first through hole 511 on the insulating protection member 50 and the arrangement area of ​​the first pressure relief hole 41 on the partition 40 are arranged opposite to each other in the thickness direction of the first cover plate 20. Along the axial direction of the second pressure relief hole 51, the projection of the second through hole 512 facing the outside of the battery cell is projected onto the first cover plate 20, thereby increasing the opening area on the insulating protection member 50 for the gas inside the battery cell to pass through. At low temperatures, this ensures that the insulating protection member 50 has sufficient strength while meeting the exhaust requirements, guaranteeing smooth exhaust and that the exhaust rate is not affected.

[0045] Furthermore, the pressure relief component 30 is positioned in the middle of the first cover plate 20. Multiple first through holes 511 are arranged in an array on the insulating protective component 50 to form a first venting area, and multiple second through holes 512 are arranged in an array to form a second venting area. When the insulating protective component 50 is formed as a strip structure, the first venting area is positioned in the middle of the insulating protective component 50, and second venting areas are provided on both sides along the length of the insulating protective component. Preferably, the area of ​​the second through holes 512 is larger than the area of ​​the first through holes 511, thus ensuring smooth venting while improving the structural strength of the first venting area and delaying the time it takes for the partition 40 to support the electrode assembly 70.

[0046] It should be noted that the gas passing through the first through hole 511 or the second through hole 512 can flow to the pressure relief component 30 via the first pressure relief hole 41 or the gas outlet channel 42 described below.

[0047] In this embodiment, when the pressure relief component 30 is opened, the connected area between the inside and outside of the battery cell at the pressure relief channel is the effective opening area of ​​the pressure relief component 30, which is S1, in mm. 2 The total area of ​​the first pressure relief hole 41 is S2, in mm. 2 The total area of ​​the second pressure relief hole 51 is S3, in mm. 2 ; 1.22≤S2 / S1≤1.3, 1.6≤S3 / S2≤2, so that at low temperatures, the insulating protective component 50 has sufficient strength while meeting the venting requirements, ensuring smooth venting and that the venting rate is not affected; when the insulating components inside the cell melt and fail, causing the electrode group 70 to move towards the pressure relief component 30 under the impact of high temperature and high pressure gas, the baffle 40 can support the electrode group 70 to ensure the venting requirements while also effectively preventing the combustion materials inside the cell from splashing out through the pressure relief component 30, thereby improving the safety performance of the cell.

[0048] The following tests were conducted on battery cells with different S1, S2 and S3 values ​​to verify that the limiting conditions of 1.22≤S2 / S1≤1.3 and 1.6≤S3 / S2≤2 can guarantee the venting requirements of the battery cells. Five sets of the same type of battery cells were used in each test to ensure the reliability and accuracy of the test results. The test results are shown in Table 1 below.

[0049] Table 1

[0050] As shown in Table 1, the areas of the first pressure relief hole 41 and the second pressure relief hole 51 have a significant impact on the cell safety test. In Examples 1-1 to 1-4, the size of S2 was too small, resulting in insufficient total area of ​​the first pressure relief hole 41 on the partition 40, leading to poor venting and problems such as shell 10 cracking and side spraying, resulting in a low cell safety test pass rate. In Examples 1-5 and 1-6, the conditions of 1.22≤S2 / S1≤1.3 and 1.6≤S3 / S2≤2 were met, satisfying the venting requirements while ensuring the structural integrity of the partition 40. The structure is strong and does not deform, effectively preventing the movement of the electrode group 70 and improving the safety performance of the cell. However, in Examples 1-7, S2 is too large, resulting in insufficient strength of the partition 40 and slight deformation. In addition, in Examples 1-8 and 1-9, due to S3 being too small, the venting is not smooth in the early stage of thermal runaway of the cell, resulting in the shell 10 cracking and a low pass rate of cell safety test. In Examples 1-10, due to S3 being too large, the strength of the insulating protection component 50 is insufficient, the insulation effect is poor, and there is a risk of insulation failure.

[0051] Furthermore, preferably, the projection of the partition 40 on the first cover plate 20 covers the pressure relief channel, thereby improving the reliability and effectiveness of the partition 40 in preventing the electrode assembly 70 from contacting the pressure relief component 30.

[0052] In this embodiment, as shown in Figures 2 and 3, the partition 40 is formed as a plate structure and is arranged parallel to the first cover plate 20, so as to avoid excessive occupation of the internal space of the cell and affecting the energy density of the cell.

[0053] Preferably, as shown in Figure 3, the thickness of the partition 40 is t. When the battery cell is a ternary system, 1.1mm≤t≤1.5mm; when the battery cell is a lithium iron phosphate system, 0.8mm≤t≤1.1mm. This ensures that the partition 40 has sufficient strength to withstand the impact of high temperature and high pressure gas and the electrode assembly 70 without deformation, thereby effectively preventing the electrode assembly 70 from blocking or sealing the pressure relief component 30.

[0054] Furthermore, in this embodiment, as shown in Figures 2 and 3, the partition 40 is disposed on the side of the support boss 21 away from the first cover plate 20. The distance between the partition 40 and the first cover plate 20 is H, where H is the height of the support boss 21 in the thickness direction of the first cover plate 20, 1mm≤H≤2mm. This allows the partition 40, the support boss 21, and the first cover plate 20 to form an exhaust channel 42. The inlet of the exhaust channel 42 is located at the circumferential edge of the partition 40, so that the gas inside the cell can not only pass through the first pressure relief hole 41 to the pressure relief member 30, but also through the exhaust channel 42 to the pressure relief member 30, thereby improving exhaust efficiency and meeting the requirement of rapid exhaust. In addition, it also avoids the size of H being too large, which would occupy the internal space of the cell and affect the energy density of the cell.

[0055] In a preferred embodiment, the partition 40 is welded to the support boss 21 to ensure that the partition 40 is firmly installed; on the surface of the first cover plate 20, the minimum distance between the support boss 21 and the pressure relief component 30 is L, where L≥4mm, thereby avoiding premature opening of the pressure relief component 30 due to the welding of the partition 40 and the support boss 21 caused by the distance L being too small.

[0056] Furthermore, in this embodiment, the support boss 21 is formed as a block structure, and the number of support bosses 21 can be one or more. Preferably, when multiple support bosses 21 are provided, the multiple support bosses 21 are arranged circumferentially around the pressure relief member 30, and the total area of ​​the projection of the support bosses 21 on the first cover plate 20 is 400 mm². 2 Up to 900mm 2 This avoids affecting the structural strength of the first cover plate 20 while ensuring that the supporting boss 21 and the partition 40 have sufficient contact area, thereby improving the firmness of the partition 40 installation.

[0057] In this embodiment, as shown in FIG3, the battery cell also includes a protective patch 31 disposed on the surface of the first cover plate 20 facing the outside of the battery cell, which is used to protect the pressure relief component 30 and prevent the pressure relief component 30 from being opened prematurely due to impact from foreign objects. Specifically, the pressure relief channel covered by the protective patch 31 allows the pressure relief component 30 to communicate with the outside of the battery cell to meet the testing requirements.

[0058] In a preferred embodiment, as shown in FIG2, the tab 71 does not protrude toward the direction close to the insulating protection member 50, so that the pole post 80 and the pressure relief member 30 are not set on the same side of the cell, that is, the pole post 80 and the pressure relief member 30 are not set on the same cover plate. If the pressure relief member 30 and the pole post 80 are set close to each other or on the same cover plate, during exhaust, the high temperature and high pressure gas gathers and sprays toward the position where the pressure relief member 30 is set, causing the pole post 80 to arc and catch fire due to the temperature. Preferably, the tab 71 and the pressure relief member 30 are set on opposite sides of the pole group 70.

[0059] Furthermore, in this embodiment, as shown in Figure 2, the battery cell also includes a second cover plate 60, an electrode post 80, and a plastic part 62. The second cover plate 60 has mounting holes and an injection hole 61, both of which are through holes. After the battery cell is assembled, electrolyte can be injected into the battery cell and a vacuum can be drawn through the injection hole 61. The end of the electrode post 80 located in the mounting hole and inside the battery cell is connected to the tab 71 on the electrode group 70 to realize the transmission of electrical energy. The second cover plate 60 is located on the side of the electrode group 70 where the tab 71 is located, and the plastic part 62 is located on the side of the second cover plate 60 facing the inside of the battery cell. In this way, the electrode group 70 and the second cover plate 60 are separated to form insulation protection and reduce the risk of short circuit.

[0060] In this embodiment, the second cover plate 60 is formed as a plate-like structure mounted on the housing 10, and both the positive terminal and the negative terminal are mounted on the second cover plate 60.

[0061] According to the battery cell provided in this application, a first cover plate is installed on the housing and has a pressure relief channel, and a pressure relief component is installed in the pressure relief channel; a support boss is provided on the side of the first cover plate facing the inside of the battery cell, and a baffle is provided on the support boss. The baffle and the pressure relief channel are spaced apart from each other, and the baffle has a first pressure relief hole. Thus, when thermal runaway occurs in the battery cell, even if the insulating components inside the battery cell melt and the electrode assembly moves towards the pressure relief component with the high-temperature and high-pressure airflow, the baffle can prevent the electrode assembly from moving further towards the pressure relief component, thereby meeting the venting requirements; an insulating protective component is provided on the side of the baffle facing the inside of the battery cell, and a second pressure relief hole is provided on the insulating protective component; when the pressure relief component is opened... The area connecting the inside and outside of the battery cell at the pressure relief channel is the effective opening area S1 of the pressure relief component. The total area of ​​the first pressure relief hole is S2, and the total area of ​​the second pressure relief hole is S3. 1.22≤S2 / S1≤1.3, 1.6≤S3 / S2≤2. In this way, at low temperatures, the insulation protection component has sufficient strength while meeting the venting requirements, ensuring smooth venting and unaffected venting rate. When the insulation component inside the battery cell melts and fails, causing the electrode group to move towards the pressure relief component under the impact of high temperature and high pressure gas, the baffle component supports the electrode group to ensure venting requirements and effectively prevents the combustion materials inside the battery cell from splashing outward through the pressure relief component, thereby improving the safety performance of the battery cell.

[0062] According to the present application, a battery pack includes the battery cells as described above. The battery cells can ensure smooth venting during thermal runaway, and the venting rate is not affected by the movement of the electrode assembly inside the battery cells, thereby improving the safety performance of the battery pack.

[0063] Finally, it should be noted that the above-described embodiments are merely specific implementations of this application, used to illustrate the technical solutions of this application, and not to limit them. The protection scope of this application is not limited thereto. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features, within the technical scope disclosed in this application. Such modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be covered within the protection scope of this application. Therefore, the protection scope of this application should be determined by the protection scope of the claims. Industrial applicability

[0064] In this application, the battery cell has a first cover plate installed on the housing and has a pressure relief channel, and a pressure relief component installed in the pressure relief channel. A support boss is provided on the side of the first cover plate facing the inside of the battery cell, and a baffle is provided on the support boss. The baffle and the pressure relief channel are spaced apart from each other, and the baffle has a first pressure relief hole. In this way, when the battery cell experiences thermal runaway, even if the insulating components inside the battery cell melt and the electrode group moves towards the pressure relief component with the high temperature and high pressure airflow, the baffle can prevent the electrode group from moving further towards the pressure relief component, thereby meeting the exhaust requirements.

Claims

1. An electric cell, characterized by, The battery cell includes: case; A first cover plate is installed on the housing. A pressure relief channel is provided on the first cover plate, and a support protrusion is provided on the side of the first cover plate facing the inside of the cell. Pressure relief components are installed in the pressure relief channel; A baffle is provided on the support boss, the baffle and the pressure relief channel are spaced apart from each other, and the baffle is provided with a first pressure relief hole; An insulating protective component is provided on the side of the partition facing the inside of the cell, and a second pressure relief hole is provided on the insulating protective component; When the pressure relief member is opened, the communication area between the inside of the battery cell and the outside of the battery cell at the pressure relief channel is an effective opening area of the pressure relief member, the effective opening area is S1, and the unit is mm 2 ; the total area of the first pressure relief hole is S2, and the unit is mm 2 ; the total area of the second pressure relief hole is S3, and the unit is mm 2 ; 1.22≤S2 / S1≤1.3, 1.6≤S3 / S2≤2.

2. The electric cell of claim 1, wherein, The partition is formed as a plate structure and is arranged parallel to the first cover plate; And / or, the thickness of the partition is t, where 1.1mm≤t≤1.5mm is the thickness of the ternary lithium battery cell, and 0.8mm≤t≤1.1mm is the thickness of the lithium iron phosphate battery cell.

3. The electric cell of claim 1, wherein, The partition is located on the side of the support boss away from the first cover plate, and the distance between the partition and the first cover plate is H, where 1mm≤H≤2mm.

4. The electric cell of claim 1, wherein, Multiple first pressure relief holes are provided, and the multiple first pressure relief holes are arranged in an array on the partition; Multiple second pressure relief holes are provided, and the multiple second pressure relief holes are arranged in an array on the insulating protective component.

5. The electric cell of claim 1, wherein, The second pressure relief hole includes a first through hole and a second through hole; along the axial direction of the second pressure relief hole, the projection of the first through hole facing the outside of the battery cell is projected onto the partition, and the projection of the second through hole facing the outside of the battery cell is projected onto the first cover plate.

6. The electric cell of claim 1, wherein, The partition is welded to the support boss; on the surface of the first cover plate, the minimum distance between the support boss and the pressure relief component is L, where L≥4mm.

7. The electric cell of claim 1, wherein, The projection of the baffle on the first cover plate covers the pressure relief channel.

8. The electric cell of claim 1, wherein, Also includes: The electrode assembly is disposed inside the housing. The insulating protective element is disposed between the first cover plate and the electrode assembly. The electrode assembly is provided with protruding electrode tabs, which do not protrude in the direction close to the insulating protective element.

9. The electric cell of claim 1, wherein, Also includes: A second cover plate is installed on the housing, and the second cover plate is provided with an installation hole and a liquid injection hole; The pole is disposed in the mounting hole.

10. A battery pack, characterized by, Includes the battery cell described in any one of claims 1 to 9.

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