Battery cells and battery packs

Abstract

The present invention relates to the field of battery technology, and in particular to a battery cell and a battery pack. The battery cell comprises: a first cover plate having a connection portion for mounting a barrier, a pressure relief member mounted on the first cover plate, the barrier member having a size of L1 in the first direction and a size of W1 in the second direction; when L0≤30mm, W0≤15, and L0 / W0≤2 on the pressure relief member, the connection portion is arranged at the four corners; the connection portion has a size of A in the first direction and a size of B in the second direction; A / L1≥1 / 4, B / W1≥1 / 4; when L0>30mm, W0>15, and L0 / W0>2 on the pressure relief member, the connection portion is arranged at both ends of the length and width of the barrier; the connection portion has a size of L2 in the first direction and a size of W2 in the second direction; L2 / L1≥1 / 3, W2 / W1≥1 / 3. The present invention can ensure that the barrier member has sufficient strength, achieve smooth exhaust, and improve the safety performance of the battery cell.

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 offer numerous advantages, including high energy density, high output power, long charge and discharge life, zero pollution, a wide operating temperature range, and low self-discharge. However, lithium-ion batteries can experience internal heat accumulation due to overcurrent, internal dendrites leading to internal short circuits, or overcharging. When this heat accumulates to a certain level, it can trigger an exothermic chain reaction in the electrolyte, cathode, and other internal materials, ultimately leading to thermal runaway.

[0003] Long cell lithium ion battery Figure 1 As shown, the electrode assembly 1 is arranged in a closed space formed by the cover plate 2 and the shell 3; the electrode ear on the electrode assembly 1 is connected to the pole on the cover plate 2; the bare cell insulating film 4 wraps around the electrode assembly 1 and is hot-melted and fixed to the lower plastic 5 on the cover plate 2 on both sides, thereby achieving isolation and insulation; the explosion-proof valve 6 on the cover plate 2 discharges the internal high-temperature and high-pressure gas to the outside of the cell when thermal runaway occurs, thereby ensuring the safety performance of the cell.

[0004] At present, the electrode assembly in the battery cell mainly relies on the lower plastic on the cover to achieve insulation and fixation, but the strength and high-temperature resistance of the lower plastic are limited. When thermal runaway occurs, the temperature is higher than the melting point of the material, causing the insulation structure to melt and fail, resulting in increased freedom of the electrode assembly in the battery cell. When the high-temperature and high-pressure gas is exhausting in the direction of the explosion-proof valve, it will drive the electrode assembly to move inside the battery cell, which is easy to block the pressure relief parts and affect the safety performance of the battery cell and battery pack. 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 in the battery cell are prone to melting during thermal runaway, causing the electrode group to move with the high-temperature and high-pressure airflow and block the explosion-proof valve on the cover plate, reducing the exhaust effect of the explosion-proof valve, thereby reducing the safety performance of the battery cell and the battery pack.

[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, wherein a protruding connection portion is formed on a side of the first cover plate facing the interior of the battery cell;

[0009] a pressure relief member, mounted on the first cover plate;

[0010] a barrier member mounted on the connecting portion so as to be spaced apart from the pressure relief member, wherein the connecting portion, the barrier member and the first cover plate form an exhaust passage connecting the interior of the battery cell and the pressure relief member;

[0011] The barrier has a size L1 in the first direction and a size W1 in the second direction;

[0012] When the length dimension L0 of the pressure relief member in the first direction is ≤30 mm, the width dimension W0 in the second direction is ≤15 mm, and L0 / W0 is ≤2, the connecting portion is provided at the four corners of the barrier member; the maximum dimension of the portion of the connecting portion in contact with the barrier member in the first direction is A, and the maximum dimension in the second direction is B; A / L1 is ≥1 / 4, and B / W1 is ≥1 / 4;

[0013] When the length dimension L0 of the pressure relief member in the first direction is greater than 30 mm, the width dimension W0 in the second direction is greater than 15 mm, and L0 / W0 is greater than 2, the connecting portion is arranged at both ends of the barrier member in the length and width directions; the maximum dimension of the portion of the connecting portion in contact with the barrier member in the first direction is L2, and the maximum dimension in the second direction is W2; L2 / L1 ≥ 1 / 3, W2 / W1 ≥ 1 / 3.

[0014] Preferably, the connecting portion is formed into a block structure, and the blocking member is provided on a surface of the connecting portion away from the first cover plate.

[0015] Preferably, in the thickness direction of the first cover plate, the height dimension of the connecting portion is H, 1mm≤H≤2.5mm.

[0016] Preferably, the barrier member is connected to the connecting portion by welding, and a gap is provided between the connecting portion and the pressure relief member.

[0017] Preferably, the barrier member is provided with first flow guide holes, and a plurality of the first flow guide holes are arranged in an array on the barrier member.

[0018] Preferably, it also includes:

[0019] an insulating protective member, disposed on a side of the first cover plate facing the interior of the battery cell, and the barrier member is sandwiched between the insulating protective member and the first cover plate;

[0020] The insulating protection member is provided with a second guide hole, and the second guide hole communicates with the interior of the battery core and the pressure relief member.

[0021] Preferably, when the connecting portions are arranged at both ends of the barrier member in the length and width directions, the connecting portions arranged at both ends in the length direction of the barrier member are formed into strip structures extending along the second direction, and the connecting portions arranged at both ends in the width direction of the barrier member are formed into strip structures extending along the first direction.

[0022] Preferably, it also includes:

[0023] The pole group is arranged in the shell; the pole group is formed with a protruding pole ear, and the pole ear protrudes in a direction away from the pressure relief member.

[0024] Preferably, it also includes:

[0025] a second cover plate connected to the housing, wherein the second cover plate and the first cover plate are arranged at two ends of the housing opposite to each other;

[0026] The pole is mounted on the second cover plate.

[0027] A second aspect of the present invention provides a battery pack comprising the battery cell described in any of the above technical solutions.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] In the battery cell of the present invention, the first cover plate is installed on the shell, and the pressure relief piece is installed on the first cover plate; a protruding connecting portion is formed on the side of the first cover plate facing the interior of the battery cell; the barrier piece is installed on the connecting portion so as to be spaced apart from the pressure relief piece, and the connecting portion, the barrier piece and the first cover plate form an exhaust channel connecting the interior of the battery cell and the pressure relief piece; when the battery cell thermally runs away, even if the pole group moves inside the battery cell, the barrier piece can prevent the pole group from blocking or blocking the pressure relief piece, and prevent internal combustion products from splashing outwards during thermal runaway, and the gas inside the battery cell can flow from the exhaust channel to the pressure relief piece, thereby ensuring smooth exhaust and improving the safety performance of the battery cell. The barrier has a dimension of L1 in the first direction and a dimension of W1 in the second direction; when the length dimension L0 of the pressure relief member in the first direction is ≤30 mm, the width dimension W0 in the second direction is ≤15, and L0 / W0 is ≤2, the connection portion is provided at the four corners of the barrier; the maximum dimension of the portion where the connection portion contacts the barrier in the first direction is A, and the maximum dimension in the second direction is B; A / L1 is ≥1 / 4, B / W1 is ≥1 / 4; when the length dimension L0 of the pressure relief member in the first direction is greater than 30 mm, the width dimension W0 in the second direction is greater than 15, and L0 / When W0>2, the connecting portion is arranged at both ends of the barrier in the length and width directions; the maximum dimension of the portion of the connecting portion in contact with the barrier in the first direction is L2, and the maximum dimension in the second direction is W2; L2 / L1≥1 / 3, W2 / W1≥1 / 3, so as to ensure that the barrier has sufficient structural strength to resist the impact of the airflow inside the battery cell, to achieve effective support for the electrode group, to avoid the situation where the high-temperature and high-pressure gas drives the electrode group to impact and deform the barrier or the exhaust area of ​​the exhaust channel is insufficient, and the pressure relief requirements cannot be met, thereby improving the safety performance of the battery cell and battery pack.

[0030] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

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

[0033] Figure 2 An exploded view of the structure of a battery cell in which the connection portions are arranged at both ends of the barrier in the length and width directions according to an embodiment of the present invention;

[0034] Figure 3 An exploded view of the structure of the insulating protective member, the first cover plate and the barrier member in a battery cell in which the connection portions are arranged at both ends of the barrier member in the length and width directions according to an embodiment of the present invention;

[0035] Figure 4 A schematic diagram of the assembly structure of the barrier member and the first cover plate in a battery cell in which the connection portions are arranged at both ends of the barrier member in the length and width directions according to an embodiment of the present invention;

[0036] Figure 5 An exploded view of the structure of the insulating protective member, the first cover plate and the barrier member in a battery cell in which the connection portions are arranged at the four corners of the barrier member according to an embodiment of the present invention;

[0037] Figure 6 A schematic structural diagram of a first cover plate in a battery cell in which connection portions are arranged at the four corners of the barrier member according to an embodiment of the present invention;

[0038] Figure 7 Schematic diagram of the assembly structure of the barrier member and the first cover plate in a battery cell in which the connecting portions are arranged at the four corners of the barrier member according to an embodiment of the present invention.

[0039] Icons: 10-first cover; 11-connecting part; 20-second cover; 21-pole; 22-plastic part; 30-shell; 40-pressure relief part; 50-barrier; 51-first guide hole; 60-exhaust channel; 70-insulating protection part; 71-second guide hole; 80-pole group; 81-pole ear; 82-insulating film; D1-first direction; D2-second direction; 1-electrode assembly; 2-cover; 3-shell; 4-bare cell insulating film; 5-lower plastic; 6-explosion-proof valve. DETAILED DESCRIPTION

[0040] The following detailed description is provided to help the reader gain a comprehensive understanding of the methods, devices, and / or systems described herein. However, various changes, modifications, and equivalents of the methods, devices, and / or systems described herein will be apparent upon understanding the disclosure of this application. For example, the order of operations described herein is merely illustrative and is not limited to the order set forth herein. Rather, except for operations that must occur in a particular order, changes may be made that will be apparent upon understanding the disclosure of this application. Furthermore, descriptions of features known in the art may be omitted for clarity and brevity.

[0041] The features described herein may be implemented in different forms and should not be construed as being limited to the examples described herein. Rather, the examples described herein have been provided merely to illustrate some of the many possible ways to implement the methods, devices, and / or systems described herein that will be apparent upon understanding the disclosure of this application.

[0042] Throughout the specification, when an element (such as a layer, region, or substrate) is described as being “on,” “connected to,” “coupled to,” “over,” or “overlaying” another element, it may be directly “on,” “connected to,” “coupled to,” “over,” or “overlaying” 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 coupled to,” “directly over,” or “directly covering” another element, there may be no other elements intervening therebetween.

[0043] As used herein, the term "and / or" includes any one of the associated listed items and any combination of any two or more items.

[0044] 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 used only to distinguish one member, component, region, layer, or portion from another member, component, region, layer, or portion. Thus, a first member, component, region, layer, or portion in the examples described herein may also be referred to as a second member, component, region, layer, or portion without departing from the teachings of the examples.

[0045] 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 encompass different orientations of the device in use or operation in addition to the orientations 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 would subsequently be "below" or "lower" relative to the other element. Thus, the term "above" includes both the orientations "above" and "below," 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.

[0046] The terms used herein are intended only to describe various examples and are not intended to limit the present disclosure. Unless the context clearly indicates otherwise, the singular is intended to include the plural. The terms "comprise," "include," and "have" list the presence of stated features, quantities, operations, components, elements, and / or combinations thereof, but do not preclude the presence or addition of one or more other features, quantities, operations, components, elements, and / or combinations thereof.

[0047] Due to manufacturing techniques and / or tolerances, variations in the shapes shown in the drawings may occur. Therefore, the examples described herein are not limited to the specific shapes shown in the drawings but include changes in shapes that occur during manufacturing.

[0048] The features of the examples described herein can 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.

[0049] According to a first aspect of the present invention, a battery cell is provided, which specifically includes a housing 30 , a first cover plate 10 , a pressure relief member 40 and a barrier member 50 .

[0050] Hereinafter, the specific structure of the battery cell according to the present embodiment as described above will be described.

[0051] In this embodiment, if Figure 2 As shown, the interior of the housing 30 has a cavity for accommodating the electrode group 80. The first cover plate 10 is mounted on the housing 30. The first cover plate 10 is formed into a plate-like structure. A protruding connection portion 11 is formed on the side of the first cover plate 10 facing the interior of the battery cell. The connection portion 11 can be formed on the first cover plate 10 through a stamping process. However, the connection portion 11 can also be assembled with the first cover plate 10 through welding, bonding, etc. A pressure relief member 40 is mounted on the first cover plate 10. The pressure relief member 40 can be an explosion-proof valve. When the pressure inside the battery cell reaches the opening pressure of the pressure relief member 40, the pressure relief member 40 explodes, connecting the inside and outside of the battery cell, thereby venting and releasing the internal pressure of the battery cell.

[0052] In this embodiment, if Figures 2 to 7As shown, the barrier 50 is installed on the connecting portion 11, so that the barrier 50 is arranged inside the battery cell and spaced apart from the pressure relief member 40. The connecting portion 11, the barrier 50 and the first cover plate 10 form an exhaust channel 60 connecting the interior of the battery cell and the pressure relief member 40. The entrance of the exhaust channel 60 is arranged at the circumferential edge of the barrier 50. Since the connecting portion 11 supports the barrier 50, there is a certain distance between the barrier 50 and the pressure relief member 40. When the battery cell thermal runaway occurs, even if the pole group 80 moves inside the battery cell, the barrier 50 can prevent the pole group 80 from blocking or blocking the pressure relief member 40, and prevent the internal combustion products from splashing outward during thermal runaway. The gas inside the battery cell can flow from the exhaust channel 60 to the pressure relief member 40, thereby ensuring smooth exhaust and improving the safety performance of the battery cell.

[0053] In a preferred embodiment, Figure 3 and Figure 5 As shown, in the thickness direction of the first cover plate 10, the height dimension of the connecting portion 11 is H, 1mm≤H≤2.5mm, so as to ensure that the exhaust channel 60 has sufficient exhaust area to ensure exhaust efficiency, and avoid the dimension of H being too large to occupy the space inside the battery cell and affect the energy density of the battery cell.

[0054] In this embodiment, if Figure 3 and Figure 7 As shown, the barrier member 50 has a dimension L1 in the first direction D1 and a dimension W1 in the second direction D2. In this embodiment, the first cover plate 10 is formed into a rectangular plate-like structure, with the first direction D1 being the length of the first cover plate 10 and the second direction D2 being the width of the first cover plate 10. The pressure relief member 40 is preferably formed into an elongated strip extending along the first direction D1, to ensure the structural strength of the first cover plate 10 while also ensuring that the pressure relief member 40 has a sufficient opening area for smooth exhaust.

[0055] Specifically, if Figures 5 to 7 As shown, when the length dimension L0 of the pressure relief member 40 in the first direction D1 is ≤30 mm, the width dimension W0 of the pressure relief member 40 in the second direction D2 is ≤15 mm, and L0 / W0 is ≤2, the connecting portion 11 is provided at the four corners of the barrier member 50; the maximum dimension of the portion of the connecting portion 11 in contact with the barrier member 50 in the first direction D1 is A, and the maximum dimension of the portion of the connecting portion 11 in contact with the barrier member 50 in the second direction D2 is B; A / L1 ≥1 / 4, B / W1 ≥1 / 4; as shown in FIG. Figures 2 to 4As shown, when the length dimension L0 of the pressure relief member 40 in the first direction D1 is greater than 30 mm, the width dimension W0 of the pressure relief member 40 in the second direction D2 is greater than 15, and L0 / W0 is greater than 2, the connecting portion 11 is arranged at both ends of the length and width directions of the barrier 50, that is, the two connecting portions 11 are respectively arranged at both ends of the barrier 50 in the first direction D1, and the two connecting portions 11 are respectively arranged at both ends of the barrier 50 in the second direction D2; the maximum dimension of the part where the connecting portion 11 contacts the barrier 50 in the first direction D1 is L2, and the maximum dimension in the second direction D2 is W2; L2 / L1≥1 / 3, W2 / W1≥1 / 3, so as to ensure that the barrier 50 has sufficient structural strength to resist the impact of the airflow inside the battery cell, realize effective support for the electrode group 80, avoid the situation where the high-temperature and high-pressure gas drives the electrode group 80 to impact and deform the barrier 50 or the exhaust area of ​​the exhaust channel 60 is insufficient, and the pressure relief requirements cannot be met, thereby improving the safety performance of the battery cell.

[0056] Next, the safety test of the battery cells of the two structures in which the connection parts 11 are arranged at the four corners and at the two ends of the length and width direction of the barrier 50 is carried out respectively to detect whether the limiting conditions of A / L1≥1 / 4 and B / W1≥1 / 4 when L0≤30mm, W0≤15 and L0 / W0≤2 and the limiting conditions of L2 / L1≥1 / 3 and W2 / W1≥1 / 3 when L0>30mm, W0>15 and L0 / W0>2 can ensure the safety of the barrier 50. 0 does not deform so that it can prevent the electrode group 80 from blocking or blocking the pressure relief part 40, meeting the exhaust requirements when the battery cell is in thermal runaway, and 5 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 of the battery cell with the size of the pressure relief part 40 being L0=20mm, W0=10 and L0 / W0=2 are shown in Table 1 below, and the test results of the battery cell with the size of the pressure relief part 40 being L0=36mm, W0=16 and L0 / W0>2 are shown in Table 2 below.

[0057] Table 1

[0058]

[0059]

[0060] As can be seen from Table 1, in Examples 1-4 to 1-8, the limiting conditions of A / L1 ≥ 1 / 4 and B / W1 ≥ 1 / 4 are met, all the battery cell safety tests are passed, and no deformation of the barrier 50 is found. The barrier 50 has sufficient structural strength to resist the impact of the airflow inside the battery cell, effectively support the electrode group 80, meet the pressure relief requirements, and ensure the safety performance of the battery cell; while in Examples 1-1 to 1-3, the ratio of A to L1 is less than 1 / 4 and / or the ratio of B to W1 is less than 1 / 4. After disassembly, it was found that the barrier 50 was deformed, resulting in a decrease in the proportion of battery cell safety test passes, and the safety performance of the battery cell cannot be guaranteed.

[0061] Table 2

[0062]

[0063]

[0064] As shown in Table 2, in Examples 2-5 to 2-8, the limiting conditions of L2 / L1≥1 / 3 and W2 / W1≥1 / 3 are met, all the battery cell safety tests are passed, and no deformation of the barrier 50 is found. The barrier 50 has sufficient structural strength to resist the impact of the airflow inside the battery cell, effectively support the electrode group 80, meet the pressure relief requirements, and ensure the safety performance of the battery cell; while in Examples 2-1 to 2-4, the ratio of L2 to L1 is less than 1 / 3 and / or the ratio of W2 to W1 is less than 1 / 3. After disassembly, it was found that the barrier 50 was deformed, resulting in a decrease in the proportion of battery cell safety test passes, and the safety performance of the battery cell cannot be guaranteed.

[0065] In this embodiment, if Figures 3 to 7 As shown, the connecting portion 11 is formed into a strip-shaped block structure. When the connecting portion 11 is arranged at both ends of the barrier member 50 in the length and width directions, the connecting portions 11 arranged at both ends in the length direction of the barrier member 50 are formed into a strip structure extending along the second direction D2, and the connecting portions 11 arranged at both ends in the width direction of the barrier member 50 are formed into a strip structure extending along the first direction D1. In this way, the effective contact area between the barrier member 50 and the connecting portion 11 is increased, and the connection strength between the barrier member 50 and the connecting portion 11 is improved.

[0066] Furthermore, if Figure 3 、 Figure 5 and Figure 6As shown, the connecting portion 11 is formed into a block structure, the barrier 50 is formed into a plate structure, the surface of the connecting portion 11 away from the first cover plate 10 is formed into a plane, and the barrier 50 is arranged on the surface of the connecting portion 11 away from the first cover plate 10, thereby increasing the contact area between the connecting portion 11 and the barrier 50, and improving the connection reliability and stability of the connecting portion 11 and the barrier 50, so as to ensure that the barrier 50 can resist the impact of the airflow inside the battery cell during thermal runaway, achieve effective support for the electrode group 80, and meet the pressure relief requirements.

[0067] In a preferred embodiment, Figure 4 Shown and Figure 7 As shown, the barrier 50 is welded to the connecting portion 11 to enhance the connection strength between the barrier 50 and the connecting portion 11. A gap is provided between the connecting portion 11 and the pressure relief member 40 to avoid affecting the pressure relief member 40 during welding of the connecting portion 11 and the barrier 50 and failing to meet the exhaust requirements.

[0068] Furthermore, in this embodiment, Figures 2 to 5 and Figure 7 As shown, a first guide hole 51 is provided on the barrier 50, and the first guide hole 51 is formed as a through-hole structure penetrating the barrier 50, so that the gas inside the battery cell can flow to the pressure relief member 40 through the first guide hole 51, thereby improving the exhaust efficiency. Preferably, multiple first guide holes 51 are arranged in an array on the barrier 50, so as to ensure the structural strength of the barrier 50 while also meeting the demand for increasing the exhaust rate.

[0069] In this embodiment, the first cover plate 10 and the barrier member 50 are both made of metal, such as aluminum or steel. Figure 2 、 Figure 3 and Figure 5 As shown, the battery cell also includes an insulating protective member 70, which is arranged on the side of the first cover plate 10 facing the interior of the battery cell, and the barrier member 50 is clamped between the insulating protective member 70 and the first cover plate 10, so that the insulating protective member 70 can separate the pole group 80 from the barrier member 50 and the first cover plate 10, thereby forming insulation protection.

[0070] Furthermore, in this embodiment, Figure 3 and Figure 5 As shown, a second guide hole 71 is provided on the insulating protective member 70. The second guide hole 71 is a through hole that penetrates the insulating protective member 70, so that the second guide hole 71 can connect the interior of the battery cell and the pressure relief member 40. Preferably, a plurality of second guide holes 71 are arranged in an array on the insulating protective member 70, so that when the temperature is low, the insulating protective member 70 has sufficient strength while meeting the exhaust requirements, ensuring smooth exhaust and unaffected exhaust rate.

[0071] In this embodiment, if Figure 2As shown, the battery cell further includes a second cover plate 20, a pole 21, and a plastic part 22. The circumferential sidewall of the pole group 80 is coated with an insulating film 82. The plastic part 22 is arranged on the side of the second cover plate 20 facing the interior of the battery cell to provide insulation protection for the second cover plate 20. The insulating film 82 and the plastic part 22 are heat-melted to achieve the fixation of the pole group 80 inside the battery cell. A protruding pole lug 81 is formed on the pole group 80, and the poles 21 are connected to the pole lugs 81. Specifically, the positive pole is connected to the positive pole lug, and the negative pole is connected to the negative pole lug. The positive pole lug and the negative pole lug are arranged on the same side of the pole group 80, and the positive pole and the negative pole are both arranged on the second cover plate 20. The second cover plate 20 and the first cover plate 10 are arranged at opposite ends of the housing 30. The pole 21 is mounted on the second cover plate 20, so that the pressure relief member 40 and the pole 21 are mounted on different cover plates. In a preferred embodiment, the first cover plate 10 and the second cover plate 20 are arranged opposite to each other on both sides of the length direction of the shell 30, and the pole ear 81 protrudes in a direction away from the pressure relief member 40 to increase the distance between the pressure relief member 40 and the pole 21, thereby reducing the impact of high-temperature and high-pressure gas on the pole 21 when it is ejected toward the pressure relief member 40, and reducing the risk of arcing and fire in the pole 21.

[0072] According to a battery cell provided by the present invention, a first cover plate is installed on a shell, and a pressure relief piece is installed on the first cover plate; a protruding connection portion is formed on the side of the first cover plate facing the interior of the battery cell; a barrier piece is installed on the connection portion so as to be spaced apart from the pressure relief piece, and the connection portion, the barrier piece and the first cover plate form an exhaust channel connecting the interior of the battery cell and the pressure relief piece; when the battery cell has thermal runaway, even if the pole group moves inside the battery cell, the barrier piece can prevent the pole group from blocking or blocking the pressure relief piece, and prevent internal combustion products from splashing outwards during thermal runaway, and the gas inside the battery cell can flow from the exhaust channel to the pressure relief piece, thereby ensuring smooth exhaust and improving the safety performance of the battery cell. The size of the barrier in the first direction is L1, and the size in the second direction is W1; when the length dimension L0 of the pressure relief member in the first direction is ≤30mm, the width dimension W0 in the second direction is ≤15, and L0 / W0 is ≤2, the connecting portion is provided at the four corners of the barrier; the maximum size of the portion of the connecting portion in contact with the barrier in the first direction is A, and the maximum size in the second direction is B; A / L1 ≥1 / 4, B / W1 ≥1 / 4; when the length dimension L0 of the pressure relief member in the first direction is greater than 30mm, the width dimension W0 in the second direction is greater than 15, and L When 0 / W0>2, the connection part is arranged at both ends of the barrier in the length and width directions; the maximum dimension of the part of the connection part in contact with the barrier in the first direction is L2, and the maximum dimension in the second direction is W2; L2 / L1≥1 / 3, W2 / W1≥1 / 3, so as to ensure that the barrier has sufficient structural strength to resist the impact of the airflow inside the battery cell, to achieve effective support for the electrode group, to avoid the situation where high-temperature and high-pressure gas drives the electrode group to impact and deform the barrier or the exhaust area of ​​the exhaust channel is insufficient, and the pressure relief requirements cannot be met, thereby improving the safety performance of the battery cell.

[0073] According to a battery pack provided by the present invention, including the battery cell as described above, a barrier is provided to prevent the pressure relief component from being blocked or blocked by the electrode group during thermal runaway, and the barrier has sufficient strength to ensure that the exhaust space meets the pressure relief requirements, thereby smoothly exhausting the gas and improving the safety performance of the battery pack.

[0074] 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 scope of protection of the present application is not limited thereto. Although the present application has been described in detail with reference to the above-described embodiments, those skilled in the art should understand that any person skilled in the art can modify or easily conceive of changes to the technical solutions described in the above-described embodiments within the technical scope disclosed in the present application, or perform equivalent replacements for some of the technical features thereof. These modifications, changes, or replacements do not deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application shall be subject to the scope of protection of the claims.

Claims

1. A battery cell, characterized in that: The battery cell comprises: case; a first cover plate, mounted on the housing, wherein a protruding connection portion is formed on a side of the first cover plate facing the interior of the battery cell; a pressure relief member, mounted on the first cover plate; a barrier member mounted on the connecting portion so as to be spaced apart from the pressure relief member, wherein the connecting portion, the barrier member and the first cover plate form an exhaust passage connecting the interior of the battery cell and the pressure relief member; The dimension of the barrier in the first direction is L1, in mm, and the dimension in the second direction is W1, in mm; When the length dimension L0 of the pressure relief member in the first direction is ≤30 mm, the width dimension W0 in the second direction is ≤15 mm, and L0 / W0 is ≤2, the connecting portion is provided at the four corners of the barrier member; the maximum dimension of the portion of the connecting portion in contact with the barrier member in the first direction is A, in mm, and the maximum dimension in the second direction is B, in mm; A / L1 is ≥1 / 4, and B / W1 is ≥1 / 4; When the length dimension L0 of the pressure relief member in the first direction is greater than 30 mm, the width dimension W0 in the second direction is greater than 15, and L0 / W0 is greater than 2, the connecting portion is arranged at both ends of the barrier member in the length and width directions; the maximum dimension of the portion of the connecting portion in contact with the barrier member in the first direction is L2, in mm, and the maximum dimension in the second direction is W2, in mm; L2 / L1 ≥ 1 / 3, W2 / W1 ≥ 1 / 3.

2. The battery cell according to claim 1, characterized in that The connecting portion is formed into a block structure, and the blocking member is arranged on a surface of the connecting portion away from the first cover plate.

3. The battery cell according to claim 1, characterized in that In the thickness direction of the first cover plate, the height dimension of the connecting portion is H, 1mm≤H≤2.5mm.

4. The battery cell according to claim 1, characterized in that The blocking member is connected to the connecting portion by welding, and a gap is provided between the connecting portion and the pressure relief member.

5. The battery cell according to claim 1, characterized in that The barrier member is provided with first guide holes, and a plurality of the first guide holes are arranged in an array on the barrier member.

6. The battery cell according to claim 1, characterized in that Also includes: an insulating protective member, disposed on a side of the first cover plate facing the interior of the battery cell, and the barrier member is sandwiched between the insulating protective member and the first cover plate; The insulating protection member is provided with a second guide hole, and the second guide hole communicates with the interior of the battery core and the pressure relief member.

7. The battery cell according to claim 1, characterized in that When the connecting portions are arranged at both ends of the barrier member in the length and width directions, the connecting portions arranged at both ends in the length direction of the barrier member are formed into strip structures extending along the second direction, and the connecting portions arranged at both ends in the width direction of the barrier member are formed into strip structures extending along the first direction.

8. The battery cell according to claim 1, characterized in that Also includes: The pole group is arranged in the shell; the pole group is formed with a protruding pole ear, and the pole ear protrudes in a direction away from the pressure relief member.

9. The battery cell according to claim 1, characterized in that: Also includes: a second cover plate connected to the housing, wherein the second cover plate and the first cover plate are arranged at two ends of the housing opposite to each other; The pole is mounted on the second cover plate.

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

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