Battery cell and battery pack

Abstract

The present application relates to the technical field of batteries, and in particular to a battery cell and a battery pack. The battery cell comprises: a first cover plate provided with an exhaust hole and formed with a protrusion protruding towards the interior of the battery cell; and a pressure relief member mounted in the exhaust hole. A support member is mounted on the protrusion, such that the support member is spaced apart from the first cover plate, and a projection of the support member on the first cover plate covers the exhaust hole; a first ventilation area is formed on the support member, and gas can flow to the exhaust hole through the first ventilation area; and the dimensions of the pressure relief member and the first ventilation area in a first direction are defined as L1 and L2, respectively, and the dimensions of the pressure relief member and the first ventilation area in a second direction are defined as W1 and W2, respectively, satisfying 1.15≤L2 / L1≤1.3 and 1.15≤W2 / W1≤1.3. In the present application, even if the displacement of an electrode assembly occurs inside the battery cell, the support member can also block the movement of the electrode assembly in a direction close to the exhaust hole, thereby preventing the electrode assembly from blocking the exhaust hole or even completely blocking the exhaust hole.

Description

Battery cells and battery packs

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese Patent Application No. CN202411916051.9, filed on December 24, 2024, entitled "Battery Cell and Battery Pack", and also claims priority to Chinese Patent Application No. CN202411916068.4, 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 representative of modern high-performance batteries due to their advantages such as high operating voltage, high specific energy, large capacity, low self-discharge, good cycle performance, long service life, light weight, and small size.

[0005] The long-cell lithium-ion battery, as shown in Figure 1, comprises: a cover plate 2, a shell 4, a bare cell insulating film 7, an electrode assembly 1, and an electrolyte. After welding, the cover plate 2 and the shell 4 form a sealed space with sufficient mechanical strength to protect the electrode assembly 1. The electrode assembly 1 is electrically connected to the electrode posts 6 on the cover plate 2 via tabs. The bare cell insulating film 7 encircles the electrode assembly 1 and is heat-fused to the lower plastic film 3 on both sides of the cover plate 2, ensuring insulation between the electrode assembly 1 and the shell 4. The cover plate 2 integrates an explosion-proof valve 5 structure for the directional discharge of high-temperature, high-pressure gases inside the battery when thermal runaway occurs due to an internal short circuit, improving battery safety.

[0006] Currently, the insulating material in battery cells is generally made of PP (polypropylene), whose strength and high temperature resistance are far lower than the temperature at which thermal runaway occurs. During thermal runaway, at least part of the insulating components in the battery cell are melted, which leads to an increase in the gap between the electrode assembly and the cover plate and shell. As the high-temperature and high-pressure gas is vented in a directional manner towards the direction where the explosion-proof valve is installed, the electrode assembly will move with the high-temperature and high-pressure gas flow and block the explosion-proof valve on the cover plate, greatly reducing the venting effect of the explosion-proof valve, thereby affecting the safety performance of the battery cell and battery pack.

[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 in the battery cell are prone to melting during thermal runaway, which leads to an increase in the gap between the electrode assembly and the cover plate and the shell, and the electrode assembly will block the explosion-proof valve on the cover plate due to the movement of high temperature and high pressure airflow, reducing the venting effect of the explosion-proof valve, thereby reducing the safety performance of the battery cell and battery pack.

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

[0010] case;

[0011] The electrode assembly is disposed within the housing;

[0012] A first cover plate is connected to the housing. The first cover plate has an exhaust hole and a protrusion that protrudes toward the inside of the battery cell.

[0013] Pressure relief component, installed at the vent;

[0014] A support member is installed on the protrusion such that the support member is spaced apart from the first cover plate, and the projection of the support member on the first cover plate covers the exhaust hole; a first ventilation area is formed on the support member;

[0015] The pressure relief component has a dimension of L1 in the first direction, in mm; the pressure relief component has a dimension of W1 in the second direction, in mm; the first ventilation area has a dimension of L2 in the first direction, in mm; the first ventilation area has a dimension of W2 in the second direction, in mm; 1.15≤L2 / L1≤1.3; 1.15≤W2 / W1≤1.3.

[0016] Beneficial effects: An exhaust port is formed on the first cover plate, and a protrusion extending towards the inside of the battery cell is created. A support member is installed on the protrusion, spaced apart from the first cover plate. The protrusion is located on a surface away from the main body of the cover plate, further separating the support member from the main body. The projection of the support member on the first cover plate covers the exhaust port and forms a first ventilation area, allowing at least a portion of the gas to flow to the exhaust port through this area. Even if the electrode assembly shifts inside the battery cell during thermal runaway, the support member can prevent the electrode assembly from moving towards the exhaust port, avoiding the electrode assembly from blocking or completely sealing the exhaust port. This also prevents internal combustibles from splashing outwards during thermal runaway, improving the safety performance of the battery cell. By limiting the dimensions of the pressure relief component and the first ventilation area, the structural strength of the support plate is ensured while also guaranteeing that the venting effect of the first ventilation area meets the pressure relief requirements, allowing the battery cell to vent smoothly during thermal runaway and improving the safety performance of the battery cell and battery pack.

[0017] In one alternative embodiment, on the surface of the first cover plate facing the inside of the cell, the minimum distance between the protrusion and the vent hole is H, where H ≥ 4 mm.

[0018] In one optional embodiment, the support member is formed as a plate-like structure parallel to the first cover plate, and the thickness of the support member is t, where 0.8mm≤t≤1.5mm.

[0019] In one alternative embodiment, the first ventilation area is provided with a plurality of first through holes arranged in an array.

[0020] In one alternative implementation, it further includes:

[0021] An insulating protective component is disposed on the side of the first cover plate facing the inside of the battery cell. The support component is disposed between the insulating protective component and the first cover plate. A second ventilation area is formed on the insulating protective component, which is opposite to the first ventilation area. The second ventilation area has a second through hole with a radial dimension of d2 in mm. The radial dimension of the first through hole is d1 in mm. 1.2≤d2 / d1≤2.

[0022] In one optional embodiment, the insulating protective component is further provided with an auxiliary exhaust area, and the auxiliary exhaust area is provided with an auxiliary vent hole.

[0023] In one optional embodiment, a plurality of protrusions are provided, and the plurality of protrusions are spaced apart around the exhaust hole. Two adjacent protrusions, the support member, and the first cover plate form an exhaust channel, through which at least a portion of the gas flows to the exhaust hole.

[0024] In one optional embodiment, the support member is a metal component;

[0025] And / or, the support member is disposed at the end of the protrusion facing the inside of the cell.

[0026] In one alternative implementation, it further includes:

[0027] A second cover plate is connected to the housing, and mounting holes are provided on the second cover plate;

[0028] A terminal post is disposed in the mounting hole, and the terminal post includes a positive terminal post and a negative terminal post.

[0029] Secondly, this application also provides a battery cell, comprising:

[0030] case;

[0031] A first cover plate is installed on the housing, and a protruding connecting portion is formed on the side of the first cover plate facing the inside of the cell;

[0032] Pressure relief components are installed on the first cover plate;

[0033] A barrier is installed on the connecting part, so that it is spaced apart from the pressure relief component. The connecting part, the barrier, and the first cover plate form an exhaust channel connecting the inside of the battery cell and the pressure relief component.

[0034] The barrier has a dimension of L4 in the first direction and a dimension of W4 in the second direction;

[0035] When the length L3 of the pressure relief component in the first direction is ≤30mm, the width W3 in the second direction is ≤15, and L3 / W3 ≤2, the connecting part is provided at the four corners of the barrier component; the maximum dimension of the part of the connecting part that contacts the barrier component in the first direction is A1, and the maximum dimension in the second direction is B1; A1 / L4 ≥ 1 / 4, B1 / W4 ≥ 1 / 4;

[0036] When the length dimension L3 of the pressure relief component in the first direction is greater than 30 mm, the width dimension W3 in the second direction is greater than 15 mm, and L3 / W3 is greater than 2, the connecting part is provided at both ends of the barrier component in the length and width directions; the maximum dimension of the part of the connecting part that contacts the barrier component in the first direction is L5, and the maximum dimension in the second direction is W5; L5 / L4≥1 / 3, W5 / W4≥1 / 3.

[0037] Beneficial effects: The first cover plate is installed on the housing, and the pressure relief component is installed on the first cover plate; a protruding connecting part is formed on the side of the first cover plate facing the inside of the cell; a barrier component is installed on the connecting part, spaced apart from the pressure relief component. The connecting part, the barrier component, and the first cover plate form an exhaust channel connecting the inside of the cell and the pressure relief component; even if the electrode assembly moves inside the cell during thermal runaway, the barrier component can prevent the electrode assembly from shielding or blocking the pressure relief component, and prevent internal combustion materials from splashing outward during thermal runaway. Gas inside the cell can flow from the exhaust channel to the pressure relief component, thus ensuring smooth exhaust and improving the safety performance of the cell. Through size design, the barrier component has sufficient structural strength to resist the impact of airflow inside the cell, achieving effective support for the electrode assembly. This avoids situations where high-temperature, high-pressure gas drives the electrode assembly to impact and deform the barrier component, or where the exhaust area of ​​the exhaust channel is insufficient to meet the pressure relief requirements, thereby improving the safety performance of the cell and battery pack.

[0038] In one alternative embodiment, the connecting portion is formed as a block structure, and the barrier is disposed on the surface of the connecting portion away from the first cover plate.

[0039] In one optional embodiment, the height dimension of the connecting portion in the thickness direction of the first cover plate is H1, where 1mm ≤ H1 ≤ 2.5mm.

[0040] In one alternative embodiment, the barrier is welded to the connecting portion, and a gap exists between the connecting portion and the pressure relief component.

[0041] In one optional embodiment, the barrier is provided with a first guide hole, and a plurality of the first guide holes are arranged in an array on the barrier.

[0042] In one alternative implementation, it further includes:

[0043] An insulating protective component is disposed on the side of the first cover plate facing the inside of the battery cell, and the barrier component is sandwiched between the insulating protective component and the first cover plate;

[0044] The insulating protective component has a second flow guide hole, which connects the inside of the battery cell and the pressure relief component.

[0045] In one optional embodiment, when the connecting portion is disposed at both ends in the length and width directions of the barrier, the connecting portion disposed at both ends in the length direction of the barrier is formed as a strip structure extending along the second direction, and the connecting portion disposed at both ends in the width direction of the barrier is formed as a strip structure extending along the first direction.

[0046] In one alternative implementation, it further includes:

[0047] An electrode assembly is disposed within the housing; protruding tabs are formed on the electrode assembly, the tabs protruding in a direction away from the pressure relief component.

[0048] In one alternative implementation, it further includes:

[0049] A second cover plate is connected to the housing, and the second cover plate and the first cover plate are disposed opposite to each other at both ends of the housing;

[0050] The pole is installed on the second cover plate.

[0051] Thirdly, this application provides a battery pack including the battery cells described in any of the above technical solutions. Attached Figure Description

[0052] 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.

[0053] Figure 1. Exploded view of the structure of a battery cell in the prior art;

[0054] Figure 2 is an exploded view of the battery cell provided in Embodiment 1 of this application;

[0055] Figure 3 is an exploded view of the structure of the first cover plate, support member and insulating protection member in the battery cell provided in Embodiment 1 of this application;

[0056] Figure 4 is an exploded view of the first cover plate, support member and insulating protection member in the battery cell provided in Embodiment 1 of this application from another perspective;

[0057] Figure 5 is a schematic diagram of the structure of the support member in the battery cell installed on the first cover plate according to Embodiment 1 of this application;

[0058] Figure 6 is a schematic diagram of the structure of the support member in the battery cell provided in Embodiment 1 of this application installed on the first cover plate from another perspective;

[0059] Figure 7 is a schematic diagram of the structure of the first cover plate in the battery cell provided in Embodiment 1 of this application;

[0060] Figure 8 is an exploded view of the battery cell structure provided in Embodiment 2 of this application, in which the connecting parts are located at both ends of the barrier in the length and width directions;

[0061] Figure 9 is an exploded view of the structure of the insulating protective component, the first cover plate, and the barrier component in the battery cell with the connecting part disposed at both ends in the length and width directions of the barrier component according to Embodiment 2 of this application;

[0062] Figure 10 is a schematic diagram of the assembly structure of the barrier in the cell and the first cover plate provided in Embodiment 2 of this application, where the connecting parts are located at both ends of the barrier in the length and width directions.

[0063] Figure 11 is an exploded view of the structure of the insulating protective component, the first cover plate, and the barrier component in the battery cell with the connection part disposed at the four corners of the barrier component according to Embodiment 2 of this application;

[0064] Figure 12 is a schematic diagram of the structure of the first cover plate in the battery cell with the connection part disposed at the four corners of the barrier, according to Embodiment 2 of this application;

[0065] Figure 13 is a schematic diagram of the assembly structure of the battery cell barrier and the first cover plate, where the connection part is located at the four corners of the barrier provided in Embodiment 2 of this application.

[0066] Icons: 10-Shell; 11-Connector; 20-Insulating film; 30-Electrode group; 31-Positive tab; 32-Negative tab; 40-First cover plate; 41-Protrusion; 42-Vent hole; 51-Pressure relief component; 52-Protective patch; 60-Support component; 61-First venting area; 611-First through hole; 62-Venting channel; 70-Insulating protective component; 71-Second venting area; 711-Second through hole; 72-Auxiliary venting area; 721-Auxiliary vent; 80-Second cover plate; 81-Positive electrode post; 82-Negative electrode post; 83-Insulating component; 84-Injection hole; 90-Barrier component; 91-First guide hole; 92-Venting channel; 1-Electrode assembly; 2-Cover plate; 3-Lower plastic; 4-Shell; 5-Explosion-proof valve; 6-Electrode post; 7-Bare cell insulating film; D1-First direction; D2-Second direction. Detailed Implementation

[0067] 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.

[0068] 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.

[0069] According to a first aspect of this application, a battery cell is provided, which specifically includes a housing 10, an electrode group 30, a first cover plate 40, a pressure relief member 51, and a support member 60.

[0070] The specific structure of the battery cell according to this embodiment, as described above, will be described below.

[0071] Examples 1-3:

[0072] In this embodiment, as shown in FIG2, a cavity is formed inside the housing 10, and the electrode assembly 30 is disposed in the cavity inside the housing 10. The electrode assembly 30 can be formed by stacking or winding positive and negative electrode sheets. The electrode assembly 30 is provided with positive electrode tab 31 and negative electrode tab 32. The electrode assembly 30 is covered with an insulating film 20 to separate the housing 10 and the electrode assembly 30, thereby forming an insulating protection.

[0073] In this embodiment, as shown in FIG2, the first cover plate 40 is formed as a plate structure, such as a rectangular plate structure. The first cover plate 40 is connected to the housing 10 and is disposed at the opening of the cavity of the housing 10. The first cover plate 40 is provided with an exhaust hole 42 and has a protrusion 41 protruding towards the inside of the battery cell. The exhaust hole 42 is formed as a through hole penetrating in the thickness direction of the first cover plate 40. The pressure relief component 51 is installed in the exhaust hole 42. When the battery cell experiences thermal runaway, the pressure relief component 51 opens so that the gas inside the battery cell can diffuse to the outside of the battery cell through the exhaust hole 42. The pressure relief component 51 can be an explosion-proof valve.

[0074] Furthermore, in this embodiment, as shown in FIG3, a protective patch 52 is provided on the side of the first cover plate 40 facing the outside of the battery cell. The protective patch 52 can be an explosion-proof valve patch. The protective patch 52 covers part of the vent hole 42 to protect the pressure relief component 51 inside the vent hole 42, so as to prevent the pressure relief component 51 from being damaged by impact and causing the pressure relief component 51 to open prematurely. The protective patch 52 only covers part of the vent hole 42, so that the outside of the battery cell can communicate with the pressure relief component 51 for detection, such as helium detection.

[0075] Furthermore, in this embodiment, as shown in Figures 3 to 5 and Figure 7, the protrusion 41 is formed as a protrusion structure, and the support member 60 is installed on the protrusion 41, such that the support member 60 is spaced apart from the first cover plate 40. The projection of the support member 60 on the first cover plate 40 covers the vent hole 42. Even if the electrode assembly 30 is displaced inside the battery cell during thermal runaway, the support member 60 can prevent the electrode assembly 30 from continuing to move towards the vent hole 42, thus avoiding the situation where the electrode assembly 30 blocks or even completely seals the vent hole 42, and preventing internal combustibles from splashing outward during thermal runaway, thereby improving the safety performance of the battery cell.

[0076] In this embodiment, as shown in Figures 3 to 7, a first ventilation area 61 is formed on the support member 60, so that at least part of the gas flows to the exhaust port 42 through the first ventilation area 61. The pressure relief member 51 has a dimension of L1 in the first direction D1 (in mm); the pressure relief member 51 has a dimension of W1 in the second direction D2 (in mm); the first ventilation area 61 has a dimension of L2 in the first direction D1 (in mm); the first ventilation area 61 has a dimension of W2 in the second direction D2 (in mm); 1.15≤L2 / L1≤1.3; 1.15≤W2 / W1≤1.3. This arrangement ensures the structural strength of the support plate while also ensuring that the exhaust effect of the first ventilation area 61 meets the pressure relief requirements, so that the battery cell can smoothly exhaust gas in the event of thermal runaway, thereby improving the safety performance of the battery cell.

[0077] The following tests were conducted on battery cells with different L1, L2, W1 and W2 values ​​to verify that the limiting conditions of 1.15≤L2 / L1≤1.3 and 1.15≤W2 / W1≤1.3 can guarantee the venting requirements in the event of thermal runaway 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.

[0078] Table 1

[0079] As shown in Table 1, in Examples 1-1 to 1-3, the ratio of the size of the first ventilation area 61 to the size of the pressure relief component 51 has a direct impact on the exhaust effect. In Examples 1-4 to 1-7, when 1.15≤L2 / L1≤1.3 and 1.15≤W2 / W1≤1.3 are satisfied, the support component 60 can take into account both exhaust and strength requirements, and the pass rate of the cell safety test is significantly increased. However, in Examples 1-8, if the size of the support component 60 is too large, it will affect the structural strength.

[0080] It should be noted that in this embodiment, the first direction D1 is perpendicular to the second direction D2. When the first cover plate 40 is a rectangular plate structure, the first direction D1 can be the length direction of the first cover plate 40, and the second direction D2 can be the width direction of the first cover plate 40. When the exhaust hole 42 is an elongated hole, the first direction D1 can be the length direction of the exhaust hole 42, and the second direction D2 is the width direction of the exhaust hole 42.

[0081] In this embodiment, the support member 60 is a metal part, for example, the support member 60 and the first cover plate 40 are both made of aluminum; the support member 60 and the protrusion 41 are welded together, and the protrusion 41 is preferably formed on the first cover plate 40 by a stamping process, which is simple to manufacture, low in cost, and reduces the battery cell assembly process.

[0082] In this embodiment, the support member 60 is disposed at the end of the protrusion 41 facing the inside of the battery cell, thereby increasing the contact area between the support member 60 and the protrusion 41 and ensuring a firm connection between them. Preferably, the total projected area of ​​the protrusion 41 on the first cover plate 40 is 400 mm². 2 Up to 900mm 2 The total area of ​​all the protrusions 41 projected onto the first cover plate 40 in the direction perpendicular to the thickness of the first cover plate 40 is 400 mm². 2 Up to 900mm 2 This ensures that the protrusion 41 can provide effective support for the support member 60.

[0083] In a preferred embodiment, as shown in FIG4, on the surface of the first cover plate 40 facing the inside of the cell, the minimum distance between the protrusion 41 and the vent 42 is H, where H≥4mm, so as to avoid the welding of the support member 60 and the protrusion 41 affecting the opening of the pressure relief member 51.

[0084] The following tests were conducted on the opening pressure values ​​of the pressure relief component 51 for battery cells with different sizes H. The opening pressure of the pressure relief component 51 was designed to be 0.9 MPa. The actual opening pressure data of the pressure relief component 51 under different H distances were compared. Multiple 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 2 below.

[0085] Table 2

[0086] As can be seen from Table 2, in Examples 2-1 to 2-3, the position of the protrusion 41 on the first cover plate 40 is close to the position of the exhaust hole 42, so the welding connection between the support member 60 and the protrusion 41 will affect the normal opening of the pressure relief member 51; while in Examples 2-4 to 2-8, the welding of the support member 60 has no significant impact on the opening pressure of the pressure relief member 51, which meets the design requirements.

[0087] In this embodiment, as shown in FIG4, the support member 60 is formed as a plate-like structure parallel to the first cover plate 40. The thickness of the support member 60 is t, 0.8mm≤t≤1.5mm, so that the support member 60 has sufficient structural strength to prevent the electrode assembly 30 from blocking or sealing the pressure relief component 51, and to avoid the t dimension being too large, which would occupy the internal space of the cell and affect the energy density of the cell. Specifically, when the cell is a ternary system and an energy storage system, 1.1mm≤t≤1.5mm, and when the cell is a lithium iron phosphate system, 0.8mm≤t≤1.1mm.

[0088] The following tests were conducted on multiple battery cell safety tests for cells with different dimensions t, and the test results were shown in Table 3 below to detect whether the support components 60 of different thicknesses were deformed after the tests.

[0089] Table 3

[0090] As shown in Table 3, in Examples 3-1 and 3-9, the support member 60 was not strong enough, and deformation of the support member 60 was found after the cell was disassembled. However, in Examples 3-2 to 3-8, the support member 60 did not have deformation problems. Therefore, the thickness of the support member 60 in the lithium iron phosphate system cell needs to be greater than or equal to 0.8 mm, while the thickness of the support member 60 in the ternary / energy storage system cell needs to be greater than or equal to 1.1 mm to ensure that the strength of the support member 60 meets the requirements and does not deform during the cell safety test.

[0091] In this embodiment, as shown in Figures 2 to 7, the first ventilation area 61 is provided with a plurality of arrayed first through holes 611, thus ensuring that the support member 60 has sufficient structural strength and meets the exhaust requirements. The first through holes 611 can be circular. The plurality of first through holes 611 can be arranged in a rectangular, circular, or shape similar to that of the exhaust hole 42.

[0092] In this embodiment, as shown in FIG5, the battery cell further includes an insulating protective component 70. The insulating protective component 70 is disposed on the side of the first cover plate 40 facing the inside of the battery cell. The support member 60 is disposed between the insulating protective component 70 and the first cover plate 40, thus separating the electrode group 30 from the first cover plate 40 and the support member 60 to form an insulating protection. A second venting area 71 is formed on the insulating protective component 70, which is disposed opposite to the first venting area 61. The second venting area 71 has a second through hole 711. The radial dimension of the second through hole 711 is d2 in mm; the radial dimension of the first through hole 611 is d1 in mm; 1.2≤d2 / d1≤2. In this way, at low temperatures, the insulating protective component 70 has sufficient strength while meeting the venting requirements, ensuring smooth venting and that the venting rate is not affected. At the same time, it can also prevent internal combustibles from splashing outward in the event of thermal runaway, thereby improving the safety performance of the battery cell.

[0093] Furthermore, in this embodiment, as shown in Figures 3 to 5, the insulating protective component 70 is also provided with an auxiliary exhaust region 72, and the auxiliary exhaust region 72 is provided with an auxiliary vent hole 721. Preferably, the auxiliary exhaust region 72 is provided with multiple auxiliary vent holes 721, the auxiliary vent holes 721 are formed into strip-shaped holes, and the area of ​​the auxiliary vent holes 721 is larger than the area of ​​the first through hole 611 and the second through hole 711, so as to accelerate exhaust and quickly alleviate thermal runaway in the event of thermal failure.

[0094] Specifically, the auxiliary exhaust area 72 is located on the side of the second ventilation area 71. Preferably, when the insulating protective member 70 is formed into a rectangular plate structure, the auxiliary exhaust area 72 is provided on both sides of the insulating protective member 70 in the length direction.

[0095] In a preferred embodiment, as shown in Figures 5 and 7, a plurality of protrusions 41 are provided, and the plurality of protrusions 41 are spaced apart around the exhaust hole 42. Two adjacent protrusions 41, the support member 60 and the first cover plate 40 form an exhaust channel 62, and at least part of the gas flows to the exhaust hole 42 through the exhaust channel 62, thereby further accelerating the exhaust of gas inside the cell.

[0096] In this embodiment, as shown in FIG4, the height dimension of the protrusion 41 in the thickness direction of the first cover plate 40 is A, 1mm≤A≤2mm, so that the protrusion 41 separates the first cover plate 40 and the support member 60. The support member 60 is formed as a plate-shaped structure parallel to the first cover plate 40, which avoids excessive occupation of the internal space of the cell while ensuring the need for rapid venting of the cell.

[0097] Furthermore, in this embodiment, as shown in FIG2, the battery cell also includes a second cover plate 80, a terminal post, and an insulating component 83. The second cover plate 80 is connected to the housing 10. The second cover plate 80 has mounting holes and a liquid injection hole 84. After the battery cell is assembled, electrolyte is injected into the battery cell through the liquid injection hole 84 and a vacuum is drawn. The terminal post is set in the mounting hole and includes a positive terminal post 81 and a negative terminal post 82. The positive terminal post 81 is connected to the positive electrode tab 31, and the negative terminal post 82 is connected to the negative electrode tab 32. The insulating component 83 is set on the side of the second cover plate 80 facing the inside of the battery cell, and is used to separate the second cover plate 80 from the conductive parts inside the battery cell, thereby forming an insulating protection. The insulating film 20 described above can be heat-fused to the insulating component 83 and the insulating protection component 70, thereby separating the conductive parts inside the battery cell from the housing 10 and the cover plate of the battery cell and reducing the risk of short circuit.

[0098] Preferably, the first cover plate 40 and the second cover plate 80 are disposed at both ends of the housing 10, so that one side of the battery cell is used for electrical connection and the other side is used for pressure relief protection in case of thermal runaway, thereby improving the safety performance of the battery cell.

[0099] According to the present application, a battery cell has an exhaust hole and a protrusion protruding towards the inside of the battery cell on a first cover plate. A support member is installed on the protrusion such that the support member is spaced apart from the first cover plate. The protrusion is on the surface away from the main body of the cover plate, so that the support member is spaced apart from the main body of the cover plate. The projection of the support member on the first cover plate covers the exhaust hole and forms a first ventilation area, so that at least part of the gas flows to the exhaust hole through the first ventilation area. Even if the electrode assembly is displaced inside the battery cell during thermal runaway, the support member can prevent the electrode assembly from moving towards the exhaust hole, thus avoiding the situation where the electrode assembly blocks or even completely seals the exhaust hole, and preventing internal combustibles from splashing outward during thermal runaway, thereby improving the safety performance of the battery cell. The pressure relief component has a dimension of L1 in the first direction and a dimension of W1 in the second direction. The first venting area has a dimension of L2 in the first direction and a dimension of W2 in the second direction. 1.15≤L2 / L1≤1.3 and 1.15≤W2 / W1≤1.3. This arrangement ensures the structural strength of the support plate while also ensuring that the exhaust effect of the first venting area meets the pressure relief requirements, enabling the battery cell to exhaust smoothly in the event of thermal runaway and improving the safety performance of the battery cell.

[0100] Examples 4-5:

[0101] In this embodiment, as shown in FIG8, the interior of the housing 10 has a cavity for accommodating the electrode assembly 30. A first cover plate 40 is installed on the housing 10. The first cover plate 40 is formed into a plate-like structure. A protruding connecting portion 11 is formed on the side of the first cover plate 40 facing the inside of the cell. The connecting portion 11 can be formed by stamping on the first cover barrier plate 40, or it can be assembled with the first cover plate 40 by welding, bonding, or other methods. A pressure relief component 51 is installed on the first cover plate 40. The pressure relief component 51 can be an explosion-proof valve. When the pressure inside the cell reaches the opening pressure of the pressure relief component 51, the pressure relief component 51 bursts, connecting the inside and outside of the cell to achieve the function of venting and releasing the internal pressure of the cell.

[0102] In this embodiment, as shown in Figures 8 to 13, the barrier 90 is installed on the connecting part 11, so that the barrier 90 is disposed inside the cell and spaced apart from the pressure relief member 51. The connecting part 11, the barrier 90, and the first cover plate 40 form an exhaust channel 92 that connects the inside of the cell and the pressure relief member 51. The inlet of the exhaust channel 92 is located at the circumferential edge of the barrier 90. Since the connecting part 11 supports the barrier 90, there is a certain distance between the barrier 90 and the pressure relief member 51. Even if the electrode group 30 moves inside the cell during thermal runaway, the barrier 90 can prevent the electrode group 30 from blocking or sealing the pressure relief member 51 and prevent the internal combustion materials from splashing outward during thermal runaway. The gas inside the cell can flow from the exhaust channel 92 to the pressure relief member 51, thereby ensuring smooth exhaust and improving the safety performance of the cell.

[0103] In a preferred embodiment, as shown in Figures 9 and 11, the height of the connecting portion 11 in the thickness direction of the first cover plate 40 is H1, where 1mm ≤ H1 ≤ 2.5mm. This ensures that the exhaust channel 92 has sufficient exhaust area to guarantee exhaust efficiency and avoids the size of H1 being too large, which would occupy the internal space of the battery cell and affect the energy density of the battery cell.

[0104] In this embodiment, as shown in Figures 6 and 13, the dimension of the barrier 90 in the first direction D1 is L4, and the dimension of the barrier 90 in the second direction D2 is W4. In this embodiment, the first cover plate 40 is formed as a rectangular plate structure, the first direction D1 is the length direction of the first cover plate 40, and the second direction D2 is the width direction of the first cover plate 40. The pressure relief member 51 is preferably formed as a long strip structure extending along the first direction D1, so as to ensure the structural strength of the first cover plate 40 while ensuring that the pressure relief member 51 has a sufficient opening area to ensure smooth air release.

[0105] Specifically, as shown in Figures 11 to 13, when the length L3 of the pressure relief component 51 in the first direction D1 is ≤30mm, the width W3 of the pressure relief component 51 in the second direction D2 is ≤15, and L3 / W3 ≤2, the connecting part 11 is provided at the four corners of the barrier component 90; the maximum dimension of the part of the connecting part 11 that contacts the barrier component 90 in the first direction D1 is A1, and the maximum dimension of the part of the connecting part 11 that contacts the barrier component 90 in the second direction D2 is B1; A1 / L4 ≥ 1 / 4, B1 / W4 ≥ 1 / 4; as shown in Figures 8 to 10, when the length L3 of the pressure relief component 51 in the first direction D1 is >30mm, the width W3 of the pressure relief component 51 in the second direction D2 is >15, and L3 / W3 > 2, the connecting part 11 is provided at the four corners of the barrier component 90. At both ends of the barrier 90 in the length and width directions, two connecting parts 11 are respectively provided at both ends of the barrier 90 in the first direction D1 and at both ends of the barrier 90 in the second direction D2. The maximum dimension of the part of the connecting part 11 that contacts the barrier 90 in the first direction D1 is L5, and the maximum dimension in the second direction D2 is W5. L5 / L4≥1 / 3, W5 / W4≥1 / 3, thus ensuring that the barrier 90 has sufficient structural strength to resist the impact of the airflow inside the cell, effectively supporting the electrode group 30, and avoiding the situation where high temperature and high pressure gas drives the electrode group 30 to impact and deform the barrier 90 or the exhaust area of ​​the exhaust channel 92 is insufficient, which would fail to meet the pressure relief requirements, thereby improving the safety performance of the cell.

[0106] The following tests were conducted on two types of battery cells: one with the connecting part 11 located at the four corners, and the other with the connecting part 11 located at both ends of the barrier 90 in the length and width directions. The tests aimed to verify whether the conditions for A1 / L4≥1 / 4 and B1 / W4≥1 / 4 when L3≤30mm, W3≤15, and L3 / W3≤2, and the conditions for L5 / L4≥1 / 3 and W5 / W4≥1 / 3 when L3>30mm, W3>15, and L3 / W3>2, could guarantee the safety of the barrier. The 90° non-deformation allows it to block the electrode group 30 from shielding or sealing the pressure relief component 51, meeting the venting requirements during thermal runaway of the battery cell. In each test, five groups of the same type of battery cell are used to ensure the reliability and accuracy of the test results. The test results of the battery cell with the pressure relief component 51 having dimensions of L3=20mm, W3=10 and L3 / W3=2 are shown in Table 4 below. The test results of the battery cell with the pressure relief component 51 having dimensions of L3=36mm, W3=16 and L3 / W3>2 are shown in Table 5 below.

[0107] Table 4

[0108] As shown in Table 4, in Examples 4-4 to 4-8, the conditions of A1 / L4≥1 / 4 and B1 / W4≥1 / 4 are met. All cell safety tests are passed and no deformation of the barrier 90 is found. The barrier 90 has sufficient structural strength to resist the impact of airflow inside the cell, effectively supporting the electrode group 30, meeting the pressure relief requirements, and ensuring the safety performance of the cell. However, in Examples 4-1 to 4-3, the ratio of A1 to L4 is less than 1 / 4 and / or the ratio of B1 to W4 is less than 1 / 4. After disassembly, it was found that the barrier 90 was deformed, which reduced the proportion of cells that passed the safety test and could not guarantee the safety performance of the cell.

[0109] Table 5

[0110] As shown in Table 5, in Examples 5-5 to 5-8, the conditions of L5 / L4≥1 / 3 and W5 / W4≥1 / 3 are met. All cell safety tests are passed and no deformation of the barrier 90 is found. The barrier 90 has sufficient structural strength to resist the impact of airflow inside the cell, effectively supporting the electrode group 30, meeting the pressure relief requirements, and ensuring the safety performance of the cell. However, in Examples 5-1 to 5-4, the ratio of L5 to L4 is less than 1 / 3 and / or the ratio of W5 to W4 is less than 1 / 3. After disassembly, deformation of the barrier 90 is found, resulting in a lower proportion of cell safety tests passing and failing to guarantee the safety performance of the cell.

[0111] In this embodiment, as shown in Figures 9 to 13, the connecting portion 11 is formed as a strip-shaped block structure. When the connecting portion 11 is disposed at both ends of the barrier member 90 in the length and width directions, the connecting portion 11 disposed at both ends of the barrier member 90 in the length direction is formed as a strip-shaped structure extending along the second direction D2, and the connecting portion 11 disposed at both ends of the barrier member 90 in the width direction is formed as a strip-shaped structure extending along the first direction D1. This increases the effective contact area between the barrier member 90 and the connecting portion 11, thereby improving the connection strength between the barrier member 90 and the connecting portion 11.

[0112] Furthermore, as shown in Figures 9, 11, and 12, the connecting portion 11 is formed as a block structure, and the barrier member 90 is formed as a plate structure. The surface of the connecting portion 11 away from the first cover plate 40 is formed as a plane, and the barrier member 90 is disposed on the surface of the connecting portion 11 away from the first cover plate 40, thereby increasing the contact area between the connecting portion 11 and the barrier member 90, improving the connection reliability and stability between the connecting portion 11 and the barrier member 90, so as to ensure that the barrier member 90 can resist the impact of the airflow inside the cell during thermal runaway, achieve effective support for the electrode group 30, and meet the pressure relief requirements.

[0113] In a preferred embodiment, as shown in Figures 10 and 13, the barrier 90 is welded to the connecting part 11 to improve the connection strength between the barrier 90 and the connecting part 11. There is a gap between the connecting part 11 and the pressure relief part 51, so as to avoid the connection part 11 and the barrier 90 affecting the pressure relief part 51 and failing to meet the exhaust requirements.

[0114] Furthermore, in this embodiment, as shown in Figures 8 to 11 and 13, a first guide hole 91 is provided on the barrier 90. The first guide hole 91 is formed as a through hole structure that penetrates the barrier 90, so that the gas inside the battery cell can flow to the pressure relief member 51 through the first guide hole 91, thereby improving the exhaust efficiency. Preferably, multiple first guide holes 91 are arranged in an array on the barrier 90, so that the structural strength of the barrier 90 can be guaranteed while also meeting the requirement of increasing the exhaust rate.

[0115] In this embodiment, both the first cover plate 40 and the barrier 90 are metal parts, such as aluminum or steel. As shown in Figures 8, 9, and 11, the battery cell also includes an insulating protection member 70, which is disposed on the side of the first cover plate 40 facing the inside of the battery cell. The barrier 90 is sandwiched between the insulating protection member 70 and the first cover plate 40, so that the insulating protection member 70 can separate the electrode group 30 from the barrier 90 and the first cover plate 40, thereby forming an insulating protection.

[0116] Furthermore, in this embodiment, as shown in Figures 9 and 11, a second through hole 711 is provided on the insulating protective component 70. The second through hole 711 is a through hole that penetrates the insulating protective component 70, so that the second through hole 711 can connect the inside of the battery cell and the pressure relief component 51. Preferably, multiple second through holes 711 are arranged in an array on the insulating protective component 70 so that the insulating protective component 70 has sufficient strength at low temperatures while meeting the venting requirements, ensuring smooth venting and that the venting rate is not affected.

[0117] In this embodiment, as shown in FIG8, the battery cell further includes a second cover plate 80, a terminal post, and an insulating member 83. The circumferential sidewall of the electrode assembly 30 is covered with an insulating film 20. The insulating member 83 is disposed on the side of the second cover plate 80 facing the inside of the battery cell, and is used to form an insulating protection for the second cover plate 80. The insulating film 20 and the insulating member 83 are thermally fused together to fix the electrode assembly 30 inside the battery cell. Protruding tabs are formed on the electrode assembly 30, and the terminal post is connected to the tab. Specifically, the positive terminal post is connected to the positive tab, and the negative terminal post 82 is connected to the negative tab 32. The positive tab and the negative tab 32 are disposed on the same side of the electrode assembly 30. The positive terminal post and the negative terminal post 82 are both disposed on the second cover plate 80. The second cover plate 80 and the first cover plate 40 are disposed opposite each other at both ends of the housing 10. The terminal post is mounted on the second cover plate 80, so that the pressure relief member 51 and the terminal post are mounted on different cover plates. In a preferred embodiment, the first cover plate 40 and the second cover plate 80 are arranged opposite each other on both sides of the housing 10 along the length direction, and the electrode tabs protrude in a direction away from the pressure relief member 51 to increase the distance between the pressure relief member 51 and the electrode post, thereby reducing the impact of high temperature and high pressure gas on the electrode post when it is ejected towards the pressure relief member 51, and reducing the risk of arcing and fire in the electrode post.

[0118] According to the present application, a battery cell has a first cover plate installed on a housing and a pressure relief component installed on the first cover plate. A protruding connecting portion is formed on the side of the first cover plate facing the inside of the battery cell. A barrier is installed on the connecting portion, which is spaced apart from the pressure relief component. The connecting portion, the barrier, and the first cover plate form an exhaust channel connecting the inside of the battery cell and the pressure relief component. Even if the electrode assembly moves inside the battery cell during thermal runaway, the barrier can prevent the electrode assembly from shielding or blocking the pressure relief component and prevent internal combustion materials from splashing outward during thermal runaway. The gas inside the battery cell can flow from the exhaust channel to the pressure relief component, thereby ensuring smooth exhaust and improving the safety performance of the battery cell. The barrier has a dimension of L4 in the first direction and W4 in the second direction. When the length L3 of the pressure relief component in the first direction is ≤30mm, the width W3 in the second direction is ≤15, and L3 / W3 ≤2, the connecting part is located at the four corners of the barrier. The maximum dimension of the portion of the connecting part that contacts the barrier is A1 in the first direction and B1 in the second direction; A1 / L4 ≥ 1 / 4, B1 / W4 ≥ 1 / 4. When the length L3 of the pressure relief component in the first direction is >30mm, and the width W3 in the second direction is >15... When L3 / W3 > 2, the connecting part is set at both ends in the length and width directions of the barrier; the maximum dimension of the part of the connecting part that contacts the barrier is L5 in the first direction and W5 in the second direction; L5 / L4 ≥ 1 / 3, W5 / W4 ≥ 1 / 3, thus ensuring that the barrier has sufficient structural strength to resist the impact of airflow inside the cell, effectively supporting the electrode group, avoiding 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, which cannot meet the pressure relief requirements, thereby improving the safety performance of the cell.

[0119] Example 6:

[0120] This embodiment provides a battery pack, including the battery cells as described in Embodiment 1. By setting a support member, the vent is prevented from being blocked or sealed by the electrode group during thermal runaway, ensuring smooth venting and improving the safety performance of the battery pack.

[0121] This embodiment also provides a battery pack, including the battery cells as described in Embodiment 2. By setting a barrier, the pressure relief component is prevented from being blocked or blocked by the electrode group during thermal runaway. The barrier has sufficient strength to ensure that the venting space meets the pressure relief requirements, allowing for smooth venting and improving the safety performance of the battery pack.

[0122] 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

[0123] The battery cell of this application has an exhaust hole on a first cover plate and a protrusion protruding towards the inside of the battery cell. A support member is installed on the protrusion such that the support member is spaced apart from the first cover plate. The protrusion is on the surface away from the main body of the cover plate, so that the support member is spaced apart from the main body of the cover plate. The projection of the support member on the first cover plate covers the exhaust hole and forms a first ventilation area, so that at least part of the gas flows to the exhaust hole through the first ventilation area. Even if the electrode assembly is displaced inside the battery cell during thermal runaway, the support member can prevent the electrode assembly from moving towards the exhaust hole, thus avoiding the situation where the electrode assembly blocks or even completely seals the exhaust hole, and preventing internal combustibles from splashing outward during thermal runaway, thereby improving the safety performance of the battery cell.

Claims

1. A battery cell, characterized in that, The battery cell includes: case; The electrode assembly is disposed within the housing; A first cover plate is connected to the housing. The first cover plate has an exhaust hole and a protrusion that protrudes toward the inside of the battery cell. Pressure relief component, installed at the vent; A support member is installed on the protrusion such that the support member is spaced apart from the first cover plate, and the projection of the support member on the first cover plate covers the exhaust hole; a first ventilation area is formed on the support member; The pressure relief component has a dimension of L1 in the first direction, in mm; the pressure relief component has a dimension of W1 in the second direction, in mm; the first ventilation area has a dimension of L2 in the first direction, in mm; the first ventilation area has a dimension of W2 in the second direction, in mm; 1.15≤L2 / L1≤1.3; 1.15≤W2 / W1≤1.

3.

2. The battery cell according to claim 1, characterized in that, On the surface of the first cover plate facing the inside of the battery cell, the minimum distance between the protrusion and the vent hole is H, where H ≥ 4 mm.

3. The battery cell according to claim 1, characterized in that, The support member is formed as a plate-shaped structure parallel to the first cover plate, and the thickness of the support member is t, where 0.8mm≤t≤1.5mm.

4. The battery cell according to claim 1, characterized in that, The first ventilation area is provided with multiple arrayed first through holes.

5. The battery cell according to claim 4, characterized in that, Also includes: An insulating protective component is disposed on the side of the first cover plate facing the inside of the battery cell. The support component is disposed between the insulating protective component and the first cover plate. A second ventilation area is formed on the insulating protective component, which is opposite to the first ventilation area. The second ventilation area has a second through hole with a radial dimension of d2 in mm. The radial dimension of the first through hole is d1 in mm. 1.2≤d2 / d1≤2.

6. The battery cell according to claim 5, characterized in that, The insulating protective component is also provided with an auxiliary exhaust area, and the auxiliary exhaust area is provided with an auxiliary vent hole.

7. The battery cell according to claim 1, characterized in that, The protrusions are provided in multiple ways, and the multiple protrusions are arranged at intervals around the exhaust hole. Two adjacent protrusions, the support member and the first cover plate form an exhaust channel, through which at least part of the gas flows to the exhaust hole.

8. The battery cell according to claim 1, characterized in that, The support component is a metal component; And / or, the support member is disposed at the end of the protrusion facing the inside of the cell.

9. The battery cell according to claim 1, characterized in that, Also includes: A second cover plate is connected to the housing, and mounting holes are provided on the second cover plate; A terminal post is disposed in the mounting hole, and the terminal post includes a positive terminal post and a negative terminal post.

10. A battery cell, characterized in that, The battery cell includes: case; A first cover plate is installed on the housing, and a protruding connecting portion is formed on the side of the first cover plate facing the inside of the cell; Pressure relief component, installed on the first cover plate; A barrier is installed on the connecting part, so that it is spaced apart from the pressure relief component. The connecting part, the barrier, and the first cover plate form an exhaust channel connecting the inside of the battery cell and the pressure relief component. The barrier has a dimension of L4 in the first direction and a dimension of W4 in the second direction; When the length L3 of the pressure relief component in the first direction is ≤30mm, the width W3 in the second direction is ≤15, and L3 / W3 ≤2, the connecting part is provided at the four corners of the barrier component; the maximum dimension of the part of the connecting part that contacts the barrier component in the first direction is A1, and the maximum dimension in the second direction is B1; A1 / L4 ≥ 1 / 4, B1 / W4 ≥ 1 / 4; When the length dimension L3 of the pressure relief component in the first direction is greater than 30 mm, the width dimension W3 in the second direction is greater than 15 mm, and L3 / W3 is greater than 2, the connecting part is provided at both ends of the barrier component in the length and width directions; the maximum dimension of the part of the connecting part that contacts the barrier component in the first direction is L5, and the maximum dimension in the second direction is W5; L5 / L4≥1 / 3, W5 / W4≥1 / 3.

11. The battery cell according to claim 10, characterized in that, The connecting portion is formed into a block structure, and the barrier is disposed on the surface of the connecting portion away from the first cover plate.

12. The battery cell according to claim 10, characterized in that, In the thickness direction of the first cover plate, the height dimension of the connecting part is H1, where 1mm≤H1≤2.5mm.

13. The battery cell according to claim 10, characterized in that, The barrier is welded to the connecting part, and there is a gap between the connecting part and the pressure relief part.

14. The battery cell according to claim 10, characterized in that, The barrier is provided with a first flow guide hole, and a plurality of the first flow guide holes are arranged in an array on the barrier.

15. The battery cell according to claim 10, characterized in that, Also includes: An insulating protective component is disposed on the side of the first cover plate facing the inside of the battery cell, and the barrier component is sandwiched between the insulating protective component and the first cover plate; The insulating protective component has a second flow guide hole, which connects the inside of the battery cell and the pressure relief component.

16. The battery cell according to claim 10, characterized in that, When the connecting portion is disposed at both ends in the length and width directions of the barrier, the connecting portion disposed at both ends in the length direction of the barrier is formed as a strip structure extending along the second direction, and the connecting portion disposed at both ends in the width direction of the barrier is formed as a strip structure extending along the first direction.

17. The battery cell according to claim 10, characterized in that, Also includes: An electrode assembly is disposed within the housing; protruding tabs are formed on the electrode assembly, the tabs protruding in a direction away from the pressure relief component.

18. The battery cell according to claim 10, characterized in that, Also includes: A second cover plate is connected to the housing, and the second cover plate and the first cover plate are disposed opposite to each other at both ends of the housing; The pole is installed on the second cover plate.

19. A battery pack, characterized in that, Includes the battery cell described in any one of claims 1 to 18.

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