Battery cell and battery pack

Abstract

The invention relates to the technical field of batteries, in particular to a battery cell and a battery pack. According to the battery cell, a first cover plate is provided with a pressure relief channel and a supporting boss; the pressure relief piece is mounted in the pressure relief channel; the blocking piece is arranged on the supporting boss, the blocking piece and the pressure relief channel are oppositely arranged in a spaced mode, a first pressure relief hole is formed in the blocking piece, and a second pressure relief hole is formed in the insulation protection piece; the effective opening area of the pressure relief piece is S1, the total area of the first pressure relief holes is S2, the total area of the second pressure relief holes is S3, S2 / S1 is larger than or equal to 1.22 and smaller than or equal to 1.3, and S3 / S2 / 1.6 is larger than or equal to 1.6 and smaller than or equal to 2. When the temperature of the battery cell is relatively low, the insulation protection piece has enough strength and ensures that the exhaust rate is not influenced; when the internal insulating part is fused and fails, and the pole group moves in the direction close to the pressure relief part, the baffle part can support the pole group to ensure the exhaust requirement, and can also prevent comburent in the battery cell from splashing outwards through the pressure relief part, so that the safety performance of the battery cell is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a battery cell and a battery pack. Background Art

[0002] Lithium-ion batteries have become the most widely used secondary 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 fields. The performance and safety requirements of lithium-ion batteries are increasing.

[0003] Long cell lithium ion battery Figure 1 As shown, the cover plate 1 integrated with the explosion-proof valve 2, the positive electrode column or the negative electrode column 3, and the lower plastic 4 is welded with the shell 5 to form a closed space for protecting the electrode assembly 6. The bare battery cell insulating film 7 covers the electrode assembly 6 and is then fixed with the lower plastic 4 on the cover plate 1 by hot melting. The explosion-proof valve 2 can be opened when the battery has thermal runaway due to an internal short circuit to discharge the high-temperature and high-pressure gas inside the battery cell in a direction, thereby improving the safety performance of the battery.

[0004] Since the electrode assembly in the battery cell is insulated and fixed by the lower plastic and the bare battery cell insulating film, and since these insulating materials are usually made of pp (polypropylene), the high temperature resistance is generally about 150°, which is lower than the temperature when thermal runaway occurs. During thermal runaway, at least part of the insulating material melts, resulting in an increase in the gap between the electrode assembly and the cover plate and the shell. When the high-temperature and high-pressure gas is exhausting in the direction where the explosion-proof valve is installed, it is easy to drive the electrode group to move toward the direction close to the explosion-proof valve, thereby blocking or blocking the explosion-proof valve, resulting in failure to exhaust in time, thereby affecting the safety performance of the battery cell. Summary of the invention

[0005] In view of this, the purpose of the present application is to provide a battery cell and a battery pack to solve the problem that the insulating components inside the battery cell are prone to melting during thermal runaway, and the gap between the electrode group, the cover plate and the shell increases, so that the electrode group will move with the high-temperature and high-pressure airflow and block or block the explosion-proof valve on the cover plate, resulting in failure to exhaust in time, thereby reducing the safety performance of the battery cell.

[0006] A first aspect of the present invention provides a battery cell, wherein the battery cell comprises:

[0007] case;

[0008] A first cover plate, mounted on the housing, a pressure relief channel is provided on the first cover plate, and a supporting boss is provided on a side of the first cover plate facing the inside of the battery cell;

[0009] A pressure relief component installed in the pressure relief channel;

[0010] A barrier member is arranged on the supporting boss, the barrier member and the pressure relief channel are arranged opposite to each other and spaced apart, and a first pressure relief hole is opened on the barrier member;

[0011] An insulating protection member is arranged on a side of the barrier member facing the inside of the battery core, and a second pressure relief hole is opened on the insulating protection member;

[0012] When the pressure relief member is opened, the communicating area between the inside of the battery cell and the outside of the battery cell at the pressure relief channel is the effective opening area of ​​the pressure relief member, and the effective opening area is S1, in 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.

[0013] Preferably, the barrier is formed into a plate-shaped structure and is arranged parallel to the first cover plate;

[0014] And / or, the thickness dimension of the barrier is t, when the battery cell is a ternary system, 1.1 mm≤t≤1.5 mm; when the battery cell is an iron-lithium system, 0.8 mm≤t≤1.1 mm.

[0015] Preferably, the barrier member is arranged on a side of the supporting boss away from the first cover plate, and a distance between the barrier member and the first cover plate is H, 1mm≤H≤2mm.

[0016] Preferably, a plurality of the first pressure relief holes are provided, and the plurality of the first pressure relief holes are arranged in an array on the baffle;

[0017] A plurality of the second pressure relief holes are provided, and the plurality of the second pressure relief holes are arranged in an array on the insulating protection member.

[0018] Preferably, 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 barrier member, and the projection of the second through hole facing the outside of the battery cell is projected onto the first cover plate.

[0019] Preferably, the barrier member is connected to the supporting boss by welding; on the surface of the first cover plate, the minimum distance between the supporting boss and the pressure relief member is L, and L≥4mm.

[0020] Preferably, the projection of the baffle on the first cover plate covers the pressure relief channel.

[0021] Preferably, it also includes:

[0022] The pole group is arranged inside the shell, the insulating protection member is arranged between the first cover plate and the pole group, and the pole group is provided with a protruding pole ear, which does not protrude in a direction close to the insulating protection member.

[0023] Preferably, it also includes:

[0024] A second cover plate is mounted on the housing, and a mounting hole and a liquid injection hole are formed on the second cover plate;

[0025] The pole is arranged in the mounting hole.

[0026] A second aspect of the present invention provides a battery pack, comprising the battery cell described in any of the above technical solutions.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] In the battery cell of the present invention, a first cover plate is installed on the shell and is provided with a pressure relief channel, and a pressure relief member is installed in the pressure relief channel; a supporting boss is provided on the side of the first cover plate facing the interior of the battery cell, a baffle is provided on the supporting boss, the baffle and the pressure relief channel are spaced apart and opposite to each other, and a first pressure relief hole is provided on the baffle, so that when thermal runaway occurs in the battery cell, even if the insulating component inside the battery cell is melted and causes the pole group to move toward the direction close to the pressure relief member with the high-temperature and high-pressure airflow, the baffle can prevent the pole group from further moving toward the pressure relief member, thereby meeting the exhaust requirement; an insulating protection member is provided on the side of the baffle facing the interior of the battery cell, and a second pressure relief hole is provided on the insulating protection member; when the pressure relief member is opened, the inside of the battery cell and The connecting area of ​​the 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 holes is S2, the total area of ​​the second pressure relief holes is S3, 1.22≤S2 / S1≤1.3, 1.6≤S3 / S2≤2, so that when the temperature is low, the insulating protection component has sufficient strength while meeting the exhaust requirements, ensuring smooth exhaust and unaffected exhaust rate; when the insulating component inside the battery cell fails due to melting, causing the electrode group to move toward the pressure relief component under the impact of high-temperature and high-pressure gas, the barrier can effectively prevent the combustion products inside the battery cell from splashing out through the pressure relief component while supporting the electrode group to meet the exhaust requirements, thereby improving the safety performance of the battery cell and the battery pack.

[0029] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0031] Figure 1 An exploded diagram of the structure of a battery cell in the prior art;

[0032] Figure 2 An exploded diagram of the structure of a battery cell provided by an embodiment of the present invention;

[0033] Figure 3 This is an exploded view of the structure of the first cover plate, the barrier member and the insulating protection member in the battery cell provided in an embodiment of the present invention.

[0034] Icons: 10-shell; 20-first cover; 21-support boss; 30-pressure relief part; 31-protective patch; 40-partitioning part; 41-first pressure relief hole; 42-air outlet channel; 50-insulating protection part; 51-second pressure relief hole; 511-first through hole; 512-second through hole; 60-second cover; 61-liquid injection hole; 62-plastic part; 70-pole group; 71-pole ear; 72-insulating film; 80-pole column; 1-cover; 2-explosion-proof valve; 3-positive pole column or negative pole column; 4-lower plastic; 5-shell; 6-electrode assembly; 7-bare cell insulating film. DETAILED DESCRIPTION

[0035] The following specific embodiments are provided to help the reader obtain a comprehensive understanding of the methods, devices and / or systems described herein. However, after understanding the disclosure of the present application, various changes, modifications and equivalents of the methods, devices and / or systems described herein will be apparent. For example, the order of operations described herein is merely an example, and is not limited to the order set forth herein, but in addition to the operations that must occur in a particular order, changes that will be apparent after understanding the disclosure of the present application may be made. In addition, in order to improve clarity and brevity, descriptions of features known in the art may be omitted.

[0036] The features described herein may be implemented in different forms and should not be interpreted as being limited to the examples described herein. Rather, the examples described herein have been provided only to illustrate some of the many possible ways of implementing the methods, devices and / or systems described herein that will be apparent after understanding the disclosure of the present application.

[0037] Throughout the specification, when an element (such as a layer, a region, or a substrate) is described as being “on”, “connected to”, “bound to”, “over”, or “covering” another element, it may be directly “on”, “connected to”, “bound to”, “over”, or “covering” another element, or one or more other elements may be present between them. In contrast, when an element is described as being “directly on”, “directly connected to”, “directly bound to”, “directly over”, or “directly covering” another element, there may be no other elements present between them.

[0038] As used herein, the term "and / or" includes any one of the associated listed items and any combination of any two or more items.

[0039] Although terms such as "first," "second," and "third" may be used herein to describe various members, components, regions, layers, or portions, these members, components, regions, layers, or portions are not limited by these terms. Rather, these terms are only used to distinguish one member, component, region, layer, or portion from another member, component, region, layer, or portion. Therefore, without departing from the teachings of the examples described herein, the first member, component, region, layer, or portion referred to may also be referred to as the second member, component, region, layer, or portion.

[0040] For ease of description, spatial relational terms such as "above", "upper", "below", and "lower" may be used herein to describe the relationship of one element to another element as shown in the accompanying drawings. Such spatial relational terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the accompanying drawings. For example, if the device in the accompanying drawings is turned over, an element described as being "above" or "upper" relative to another element will subsequently be located "below" or "lower" relative to the other element. Therefore, the term "above" includes both "above" and "below" orientations depending on the spatial orientation of the device. The device may also be positioned in other ways (e.g., rotated 90 degrees or in other orientations), and the spatial relational terms used herein will be interpreted accordingly.

[0041] The terms used herein are only used to describe various examples and are not used to limit the present disclosure. Unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. The terms "include", "comprise" and "have" list the stated features, quantities, operations, components, elements and / or their combinations that exist, but do not exclude the existence or addition of one or more other features, quantities, operations, components, elements and / or their combinations.

[0042] Variations in the shapes shown in the drawings may occur due to manufacturing techniques and / or tolerances. Therefore, the examples described herein are not limited to the specific shapes shown in the drawings but include variations in shapes that occur during manufacturing.

[0043] The features of the examples described herein may be combined in various ways that will be apparent after understanding the disclosure of the present application. In addition, although the examples described herein have various configurations, other configurations are possible as will be apparent after understanding the disclosure of the present application.

[0044] According to a first aspect of the present invention, a battery cell is provided, which specifically includes a housing 10 , a first cover plate 20 , a pressure relief member 30 , a barrier member 40 and an insulating protection member 50 .

[0045] Hereinafter, the specific structure of the battery cell according to the present embodiment as described above will be described.

[0046] In this embodiment, if Figure 2 As shown, a cavity is provided inside the shell 10, and a pole group 70 is provided in the cavity inside the shell 10. The pole group 70 may be formed by laminating pole pieces or winding pole pieces. A protruding pole ear 71 is provided on the pole group 70, and the pole ear 71 includes a positive pole ear 71 and a negative pole ear 71. The first cover plate 20 is installed on the shell 10, and 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, and the pressure relief channel is formed as a channel penetrating the first cover plate 20 in the thickness direction of the first cover plate 20, so as to realize the connection between the inside and outside of the battery cell. The pressure relief member 30 is installed in the pressure relief channel, and the pressure relief member 30 may be an explosion-proof valve. When the pressure inside the battery cell reaches the opening pressure of the pressure relief member 30, the pressure relief member 30 opens, so that the inside and outside of the battery cell are connected, so as to facilitate the discharge of the gas in the battery cell.

[0047] In this embodiment, if Figure 3As shown, a support boss 21 is provided on the side of the first cover plate 20 facing the inside of the battery cell, and 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. The barrier 40 is provided on the support boss 21. In the thickness direction of the first cover plate 20, the barrier 40 and the pressure relief channel are spaced apart from each other and a first pressure relief hole 41 is provided on the barrier 40. The first pressure relief hole 41 is a through hole that penetrates the barrier 40. In this way, when thermal runaway occurs in the battery cell, even if the insulating component inside the battery cell is hot-melted and causes the pole group 70 to move toward the direction close to the pressure relief component 30 with the high-temperature and high-pressure airflow, the barrier 40 can also prevent the pole group 70 from further moving toward the pressure relief component 30, thereby meeting the exhaust requirements. It should be noted that in this embodiment, the insulating component inside the battery cell is an insulating protective component 50, an insulating film 72 or a plastic component 62 as described below.

[0048] In this embodiment, if Figure 2 and Figure 3 As shown, the insulating protection member 50 is arranged on the side of the partition member 40 facing the inside of the battery cell, and the insulating protection member 50 is arranged between the first cover plate 20 and the pole group 70, and is used to separate the pole 80 and the first cover plate 20 on which the partition member 40 is installed to form insulating protection for the first cover plate 20. A second pressure relief hole 51 is opened on the insulating protection member 50, and the second pressure relief hole 51 is a through hole that penetrates the insulating protection member 50.

[0049] In a preferred embodiment, Figure 2 and Figure 3 As shown, 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 barrier member 40. The first pressure relief holes 41 can be arranged in an array in a rectangular, circular or shape that is the same as the outer edge contour shape 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 protection member 50.

[0050] Furthermore, if Figure 3 As shown, 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 on the baffle 40, so that the layout area of ​​the first through hole 511 on the insulating protection member 50 and the layout area of ​​the first pressure relief hole 41 on the baffle 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 on the first cover plate 20, thereby increasing the opening area on the insulating protection member 50 for the internal gas of the power cell to pass through, so that when the temperature is low, the insulating protection member 50 has sufficient strength while meeting the exhaust requirements, ensuring smooth exhaust and unaffected exhaust rate.

[0051] Furthermore, the pressure relief member 30 is arranged in the middle of the first cover plate 20, and a plurality of first through holes 511 are arranged in an array on the insulating protection member 50 to form a first exhaust area, and a plurality of second through holes 512 are arranged in an array to form a second exhaust area. When the insulating protection member 50 is formed into a strip structure, the first exhaust area is arranged in the middle of the insulating protection member 50, and the second exhaust area is arranged on both sides of the length direction of the insulating protection member. Preferably, the area of ​​the second through hole 512 is larger than the area of ​​the first through hole 511, so that the structural strength of the first exhaust area is improved while ensuring smooth exhaust, and the time for the barrier member 40 to support the pole group 70 is delayed.

[0052] It should be noted that the gas passing through the first through hole 511 or the second through hole 512 may flow to the pressure relief member 30 via the first pressure relief hole 41 or the gas outlet channel 42 described below.

[0053] In this embodiment, when the pressure relief member 30 is opened, the communicating area between the inside of the battery cell and the outside of the battery cell at the pressure relief channel is the effective opening area of ​​the pressure relief member 30. The effective opening area of ​​the pressure relief member 30 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 when the temperature is low, the insulating protection part 50 has sufficient strength while meeting the exhaust requirements, ensuring smooth exhaust and unaffected exhaust rate; when the insulating component inside the battery cell fails due to melting, causing the pole group 70 to move toward the pressure relief part 30 under the impact of high-temperature and high-pressure gas, the barrier part 40 can support the pole group 70 to meet the exhaust requirements while effectively preventing the combustion products inside the battery cell from splashing outward through the pressure relief part 30, thereby improving the safety performance of the battery cell.

[0054] Several groups of safety tests are conducted on battery cells with different S1, S2 and S3 to detect whether the limiting conditions of 1.22≤S2 / S1≤1.3 and 1.6≤S3 / S2≤2 can guarantee the exhaust requirements of the battery cells. Five groups of similar battery cells are used in each group of tests to ensure the reliability and accuracy of the test results. The test results are shown in Table 1 below.

[0055] Table 1

[0056]

[0057]

[0058] As shown in Table 1, the areas of the first pressure relief hole 41 and the second pressure relief hole 51 have a great influence on the safety test of the battery cell. In Examples 1-1 to 1-4, due to the small size of S2, the total area of ​​the first pressure relief hole 41 on the baffle 40 is insufficient, the exhaust is not smooth, and there are problems such as shell 10 rupture and side spray, and the pass rate of the battery cell safety test is low. In Examples 1-5 and 1-6, the limiting conditions of 1.22≤S2 / S1≤1.3 and 1.6≤S3 / S2≤2 are met, which meets the exhaust requirements while ensuring the structure of the baffle 40. The structural strength is stable and does not deform, which can effectively block the movement of the pole group 70 and improve the safety performance of the battery cell; however, in Example 1-7, S2 is too large, resulting in insufficient strength of the barrier 40 and slight deformation; in addition, in Example 1-8 and Example 1-9, due to S3 being too small, the exhaust of the battery cell in the early stage of thermal runaway is not smooth, and there is a problem of shell 10 rupture, resulting in a low pass rate of the battery cell safety test; in Example 1-10, due to S3 being too large, the strength of the insulating protection part 50 is insufficient, the insulation effect is poor, and there is a risk of insulation failure.

[0059] Furthermore, preferably, the projection of the barrier member 40 on the first cover plate 20 covers the pressure relief channel, thereby improving the reliability and effectiveness of the barrier member 40 in blocking the electrode group 70 from contacting the pressure relief member 30 .

[0060] In this embodiment, if Figure 2 and Figure 3 As shown, the barrier 40 is formed into a plate-like structure and is arranged parallel to the first cover plate 20, so as to avoid excessive occupation of the internal space of the battery cell and affecting the energy density of the battery cell.

[0061] Preferably, if Figure 3 As shown, the thickness dimension of the barrier member 40 is t. When the battery cell is a ternary system, 1.1mm≤t≤1.5mm; when the battery cell is an iron-lithium system, 0.8mm≤t≤1.1mm. This ensures that the barrier member 40 has sufficient strength and does not deform under the impact of high-temperature and high-pressure gas and the electrode group 70, thereby effectively preventing the electrode group 70 from blocking or blocking the pressure relief member 30.

[0062] Furthermore, in this embodiment, if Figure 2 and Figure 3As shown, the barrier 40 is arranged on the side of the support boss 21 away from the first cover plate 20, and the distance between the barrier 40 and the first cover plate 20 is H, where H is the height dimension of the support boss 21 in the thickness direction of the first cover plate 20, 1mm≤H≤2mm, so that the barrier 40, the support boss 21 and the first cover plate 20 form an outlet channel 42, and the inlet of the outlet channel 42 is arranged at the circumferential edge of the barrier 40, so that the gas inside the battery cell can not only pass from the first pressure relief hole 41 to the pressure relief member 30, but also pass through the outlet channel 42 to the pressure relief member 30, thereby improving the exhaust efficiency and meeting the rapid exhaust requirements. In addition, it also avoids the size of H being too large and occupying the space inside the battery cell to affect the energy density of the battery cell.

[0063] In a preferred embodiment, the baffle 40 is welded to the supporting boss 21, thereby ensuring that the baffle 40 is firmly installed; on the surface of the first cover plate 20, the minimum distance between the supporting boss 21 and the pressure relief member 30 is L, L ≥ 4mm, thereby avoiding the pressure relief member 30 being affected by the welding of the baffle 40 and the supporting boss 21 and causing premature opening due to the distance L being too small.

[0064] Furthermore, in this embodiment, the support boss 21 is formed into a block structure, and the number of the support boss 21 can be one or more. Preferably, when there are multiple support bosses 21, the multiple support bosses 21 are arranged at intervals around the circumference of the pressure relief member 30, and the total area of ​​the projection of the support boss 21 on the first cover plate 20 is 400mm 2 Up to 900mm 2 This can avoid affecting the structural strength of the first cover plate 20 while ensuring that the supporting boss 21 and the barrier member 40 have a sufficient contact area, thereby improving the firmness of the installation of the barrier member 40.

[0065] In this embodiment, if Figure 3 As shown, the battery cell also includes a protective patch 31 arranged on the surface of the first cover plate 20 facing the outside of the battery cell, which is used to protect the pressure relief member 30 to prevent the pressure relief member 30 from being hit by foreign objects and opening prematurely. Specifically, the protective patch 31 covers part of the pressure relief channel, so that the pressure relief member 30 can be connected to the outside of the battery cell to meet the detection requirements.

[0066] In a preferred embodiment, Figure 2As shown, the pole ear 71 does not protrude in the direction close to the insulating protection member 50, so that the pole 80 and the pressure relief member 30 are not arranged on the same side of the battery cell, that is, the pole 80 and the pressure relief member 30 are not arranged on the same cover plate. If the pressure relief member 30 and the pole 80 are arranged relatively close or on the same cover plate, during exhaust, high-temperature and high-pressure gas will gather and erupt toward the position where the pressure relief member 30 is arranged, causing the pole 80 to arc and catch fire due to the influence of temperature. Preferably, the pole ear 71 and the pressure relief member 30 are arranged on two sides of the pole group 70 opposite to each other.

[0067] In addition, in this embodiment, Figure 2 As shown, the battery cell also includes a second cover plate 60, a pole 80 and a plastic part 62. The second cover plate 60 is provided with a mounting hole and a liquid injection hole 61. Both the mounting hole and the liquid injection hole 61 are through holes. After the battery cell is assembled, electrolyte can be injected into the battery cell and vacuum can be drawn through the liquid injection hole 61. The pole 80 is arranged in the mounting hole and one end located inside the battery cell is connected to the pole ear 71 on the pole group 70 to realize the transmission of electric energy. The second cover plate 60 is arranged on the side of the pole group 70 where the pole ear 71 is arranged. The plastic part 62 is arranged on the side of the second cover plate 60 facing the inside of the battery cell, so that the pole group 70 and the second cover plate 60 are separated to form insulation protection and reduce the risk of short circuit.

[0068] In the present embodiment, the second cover plate 60 is formed as a plate-shaped structure mounted on the housing 10 , and both the positive electrode column and the negative electrode column are mounted on the second cover plate 60 .

[0069] According to a battery cell provided by the present invention, a first cover plate is installed on the shell and is provided with a pressure relief channel, and a pressure relief member is installed in the pressure relief channel; a supporting boss is provided on the side of the first cover plate facing the interior of the battery cell, a baffle is provided on the supporting boss, the baffle and the pressure relief channel are spaced apart from each other, and a first pressure relief hole is provided on the baffle, so that when thermal runaway occurs in the battery cell, even if the insulating component inside the battery cell is melted and causes the pole group to move toward the direction close to the pressure relief member with the high-temperature and high-pressure airflow, the baffle can prevent the pole group from further moving toward the pressure relief member, thereby meeting the exhaust requirement; an insulating protection member is provided on the side of the baffle facing the interior of the battery cell, and a second pressure relief hole is provided on the insulating protection member; when the pressure relief member is opened The connecting area between 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 holes is S2, the total area of ​​the second pressure relief holes is S3, 1.22≤S2 / S1≤1.3, 1.6≤S3 / S2≤2, so that when the temperature is low, the insulating protection component has sufficient strength while meeting the exhaust requirements, ensuring smooth exhaust and unaffected exhaust rate; when the insulating component inside the battery cell fails due to melting, causing the pole group to move toward the pressure relief component under the impact of high-temperature and high-pressure gas, the barrier component can effectively prevent the combustion products inside the battery cell from splashing out through the pressure relief component while supporting the pole group to meet the exhaust requirements, thereby improving the safety performance of the battery cell.

[0070] A battery pack provided according to the present invention includes the battery cell as described above. The battery cell can ensure smooth exhaust when thermal runaway occurs, and the exhaust rate is not affected by the movement of the electrode group inside the battery cell, thereby improving the safety performance of the battery pack.

[0071] Finally, it should be noted that the above-described embodiments are only specific implementation methods of the present application, which are used to illustrate the technical solutions of the present application, rather than to limit them. The protection scope of the present application is not limited thereto. Although the present application is described in detail with reference to the above-described embodiments, ordinary technicians in the field should understand that any technician familiar with the technical field can still modify the technical solutions recorded in the above-described embodiments within the technical scope disclosed in the present application, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A battery cell, characterized in that: The battery cell comprises: case; A first cover plate, mounted on the housing, a pressure relief channel is provided on the first cover plate, and a supporting boss is provided on a side of the first cover plate facing the inside of the battery cell; A pressure relief component installed in the pressure relief channel; A barrier member is arranged on the supporting boss, the barrier member and the pressure relief channel are arranged opposite to each other and spaced apart, and a first pressure relief hole is opened on the barrier member; An insulating protection member is arranged on a side of the barrier member facing the inside of the battery core, and a second pressure relief hole is opened on the insulating protection member; When the pressure relief member is opened, the communicating area between the inside of the battery cell and the outside of the battery cell at the pressure relief channel is the effective opening area of ​​the pressure relief member, and the effective opening area is S1, in 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.

2. The battery cell according to claim 1, characterized in that: The barrier is formed into a plate-shaped structure and is arranged parallel to the first cover plate; And / or, the thickness dimension of the barrier is t, when the battery cell is a ternary system, 1.1 mm≤t≤1.5 mm; when the battery cell is an iron-lithium system, 0.8 mm≤t≤1.1 mm.

3. The battery cell according to claim 1, characterized in that: The barrier member is arranged on a side of the supporting boss away from the first cover plate, and a distance between the barrier member and the first cover plate is H, 1mm≤H≤2mm.

4. The battery cell according to claim 1, characterized in that: There are a plurality of first pressure relief holes, and the plurality of first pressure relief holes are arranged in an array on the barrier member; A plurality of the second pressure relief holes are provided, and the plurality of the second pressure relief holes are arranged in an array on the insulating protection member.

5. The battery cell according to claim 1, characterized in that: 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 on the barrier, and the projection of the second through hole facing the outside of the battery cell is projected on the first cover plate.

6. The battery cell according to claim 1, characterized in that: The baffle is connected to the supporting boss by welding; on the surface of the first cover plate, the minimum distance between the supporting boss and the pressure relief member is L, and L is ≥ 4 mm.

7. The battery cell according to claim 1, characterized in that: The projection of the baffle on the first cover plate covers the pressure relief channel.

8. The battery cell according to claim 1, characterized in that: Also includes: The pole group is arranged inside the shell, the insulating protection member is arranged between the first cover plate and the pole group, and the pole group is provided with a protruding pole ear, which does not protrude in a direction close to the insulating protection member.

9. The battery cell according to claim 1, characterized in that: Also includes: A second cover plate is mounted on the housing, and a mounting hole and a liquid injection hole are formed on the second cover plate; The pole is arranged in the mounting hole.

10. A battery pack, characterized in that: A battery cell comprising any one of claims 1 to 9.

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