Battery, battery module, and battery pack

Abstract

The present application relates to the technical field of batteries, and discloses a battery, a battery module, and a battery pack. The battery comprises a housing and an electrode assembly. In a blade battery of the structure, the length of the housing and the length of a negative electrode sheet satisfy (I), so that two ends of the electrode assembly maintain appropriate distances from cover plate assemblies after the electrode assembly is inserted into the housing, ensuring that tabs on the two sides of the electrode assembly can be normally bent; and the gaps between end portions of the electrode assembly and the corresponding cover plate assemblies are moderate to prevent the tabs from tearing after vibration testing. In the height direction, gaps between upper and lower ends of the electrode assembly and the inner wall of the housing are moderate to prevent interference between the electrode assembly and the housing during insertion and prevent friction of the inner wall of the housing from damaging an inner insulating film and separator outside the electrode assembly, which may cause a risk of short circuit in the electrode assembly. In addition, the gaps between the upper and lower ends of the electrode assembly and the inner wall of the housing are moderate to prevent the tabs from tearing during vibration testing.

Description

Batteries, battery modules and battery packs

[0001] Cross-reference of related applications

[0002] This application claims priority to Chinese Patent Application No. 202410667669.X, filed on May 28, 2024, entitled "Battery, Battery Module 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, specifically to a battery, a battery module, and a battery pack. Background Technology

[0004] Existing batteries, such as blade batteries, include structures including a casing, electrode assembly, and cover plate assembly. The casing has openings at both ends, the electrode assembly is located inside the casing, and the cover plate assembly is located on the openings at both ends of the casing. The electrode assembly includes a positive electrode, a separator, and a negative electrode, with the positive and negative electrodes stacked alternately, and the separator located between the positive and negative electrodes. In existing lithium batteries, to prevent lithium plating, the negative electrode is usually designed to be larger than the positive electrode, and the edge of the separator extends beyond the edge of the negative electrode to provide insulation between the positive and negative electrodes. Existing blade batteries are prone to damage to the insulating film and separator during electrode assembly insertion into the casing; or, after the blade battery is assembled and subjected to vibration testing, the electrode tabs are easily damaged or torn. Summary of the Invention

[0005] In view of this, this application provides a battery, a battery module, and a battery pack to solve the problem that the separator of the battery is easily damaged after assembly or the tabs are easily damaged or torn after vibration testing in the prior art.

[0006] In a first aspect, this application provides a battery comprising:

[0007] The shell has openings at both ends along its length; the length of the shell is L, and the height between the inner surface of the bottom wall and the inner surface of the top wall of the shell is H.

[0008] An electrode assembly is disposed within the housing. The electrode assembly includes a positive electrode sheet, a separator, and a negative electrode sheet stacked together. The area of ​​the negative electrode sheet is larger than the area of ​​the positive electrode sheet. The outer edge of the separator extends beyond the outer edges of both the positive and negative electrode sheets. The length of the negative electrode sheet is L1, and the height of the negative electrode sheet is H1. 0.67% ≤ (H-H1) / H ≤ 12.5%, 0.96% ≤ (L-L1) / L ≤ 13.33%.

[0009] Beneficial effects: In this battery structure, the length of the casing and the length of the negative electrode meet the requirements. This ensures that after the electrode assembly is installed in the housing, both ends of the electrode assembly maintain an appropriate distance from the cover plate assembly, guaranteeing that the tabs on both sides of the electrode assembly can be bent normally after installation, and that the bent tabs connect to the electrode posts on the cover plate assembly; simultaneously The appropriate spacing between the electrode assembly ends and the cover plate assembly prevents excessive spacing and effectively prevents the electrode assembly from shaking relative to the casing after installation, ensuring the battery can pass vibration testing and preventing electrode tab tearing after vibration testing. The height between the inner surface of the bottom wall and the inner surface of the top wall of the casing meets the height requirements of the negative electrode sheet. In the vertical direction, the distance between the upper and lower ends of the electrode assembly and the inner wall of the housing is moderate. This prevents interference between the electrode assembly and the housing when the negative electrode plate is too large, which could prevent the electrode assembly from being installed in the housing, or cause the inner insulating film and diaphragm outside the electrode assembly to be damaged by friction on the inner wall of the housing during installation, leading to a short circuit risk. Simultaneously... In the vertical direction, the distance between the upper and lower ends of the electrode assembly and the inner wall of the housing is moderate to prevent excessive spacing and ensure that the electrode assembly can be stably held in the housing after installation, preventing the tabs from tearing during vibration testing. In addition, the distance between the electrode assembly and the housing and cover plate assembly is moderate to prevent the housing or cover plate assembly from damaging the negative electrode sheet, ensuring the area of ​​the negative electrode sheet and preventing lithium plating.

[0010] In one alternative embodiment, the outer edge of the negative electrode extends beyond the outer edge of the positive electrode.

[0011] In one alternative implementation,

[0012] In one optional embodiment, the outer edge of one side of the positive electrode extends beyond the outer edge of the negative electrode along its length; the other sides of the positive electrode are located inside the negative electrode.

[0013] In one optional embodiment, the distance by which the outer edge of one side of the positive electrode extends beyond the outer edge of the negative electrode in the longitudinal direction is d, where 1mm≤d≤5mm.

[0014] In one alternative embodiment, an insulating layer is provided on the side of the positive electrode that extends beyond the outer edge of the negative electrode.

[0015] Beneficial effects: After the separator on the side of the positive electrode with the insulating layer is damaged, the insulating layer can isolate the positive and negative electrodes, preventing short circuits between the positive and negative electrodes and effectively ensuring the safety performance of the battery.

[0016] In one optional embodiment, a pressure relief mechanism is further included, which is disposed on the bottom wall of the housing.

[0017] And / or, the battery further includes a cover assembly disposed on the opening; the cover assembly includes a terminal post, and the tabs on both sides of the terminal group along the length direction are electrically connected to the terminal post.

[0018] In an optional embodiment, a pressure relief mechanism and a cover plate assembly are further included, the pressure relief mechanism being disposed on the cover plate assembly, 0.67%.

[0019] Secondly, this application also provides a battery module, including the battery described in any of the above descriptions. The battery module includes the battery and has the same effects as the battery, which will not be elaborated further here.

[0020] Thirdly, this application also provides a battery pack, including the aforementioned battery module. The battery pack includes a battery and has the same effect as a battery, which will not be described in detail here. Attached Figure Description

[0021] 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.

[0022] Figure 1 is a schematic diagram of the arrangement of a positive electrode, a separator, and a negative electrode in a battery according to an embodiment of this application;

[0023] Figure 2 is a schematic diagram of the arrangement of the positive electrode, separator and negative electrode in another battery according to an embodiment of this application;

[0024] Figure 3 is a schematic diagram of the casing of a battery according to an embodiment of this application;

[0025] Figure 4 is a side view of the casing of a battery according to an embodiment of this application;

[0026] Figure 5 is a schematic diagram of a battery according to an embodiment of this application;

[0027] Figure 6 is a cross-sectional view of a battery according to an embodiment of this application;

[0028] Figure 7 is a partial enlarged view of part A in Figure 6;

[0029] Figure 8 is a side view of another battery according to an embodiment of this application;

[0030] Figure 9 is a sectional view along line AA of Figure 8;

[0031] Figure 10 is a magnified view of part B in Figure 9;

[0032] Figure 11 is a schematic diagram of the shell in Figure 9;

[0033] Figure 12 is a magnified view of part C in Figure 6.

[0034] Explanation of reference numerals in the attached drawings: 1. Shell; 2. Electrode assembly; 201. Positive electrode plate; 2011. Positive electrode tab; 202. Diaphragm; 203. Negative electrode plate; 2031. Negative electrode tab; 3. Cover plate assembly; 4. Support component; 5. Pressure relief mechanism; 6. Inner insulating membrane; 7. Outer insulating membrane. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0036] During battery manufacturing, after the electrodes are fabricated, the positive electrode, separator, and negative electrode are stacked and pressed together to form an electrode assembly. To prevent lithium plating, the negative electrode is usually designed to be larger than the positive electrode, and the edge of the separator extends beyond the edge of the negative electrode to provide insulation between the positive and negative electrodes. The casing is open at both ends, and tabs extend from both sides along the length of the electrode assembly. These tabs are bent and connected to the terminals on the side cover assemblies.

[0037] In related technologies, the size of the negative electrode sheet is not compatible with the size of the casing. For example, when the size of the negative electrode sheet is too large, interference occurs between the electrode assembly and the casing when it is inserted, resulting in damage to the insulating film and separator after the electrode assembly is inserted. Or, after insertion, the length of the negative electrode sheet is too long, and the space in the casing along the length direction is insufficient, making it impossible to bend the tabs on one or both sides of the electrode assembly. When the size of the negative electrode sheet differs greatly from the size of the casing, the distance between the electrode assembly and the inner wall of the upper and lower ends of the casing is large after the electrode assembly is inserted, or the distance between the electrode assembly and the cover plate assembly is too large, making it difficult for the electrode assembly to be stably kept in the casing. During vibration testing, the tabs are easily damaged or torn, and the battery cannot meet the vibration test requirements.

[0038] The embodiments of this application are described below with reference to Figures 1 to 12.

[0039] According to an embodiment of this application, a battery is provided, including a housing 1 and an electrode assembly 2.

[0040] The shell 1 has openings at both ends along its length; the length of the shell 1 is L, and the height between the inner surface of the bottom wall and the inner surface of the top wall of the shell 1 is H; the electrode assembly 2 is disposed inside the shell 1, and the electrode assembly 2 includes a positive electrode 201, a diaphragm 202 and a negative electrode 203 stacked together; the area of ​​the negative electrode 203 is larger than the area of ​​the positive electrode 201; the outer edge of the diaphragm 202 extends beyond the outer edges of the positive electrode 201 and the negative electrode 203; the length of the negative electrode 203 is L1, and the height of the negative electrode 203 is H1; The two ends of the housing are suitable for mounting cover plate assemblies 3; the cover plate assembly 3 includes pole posts, and the pole lugs on both sides of the pole group 2 in the length direction are suitable for electrical connection with the pole posts.

[0041] In this battery structure, the length of the casing 1 and the length of the negative electrode 203 satisfy the following... This ensures that after the electrode assembly 2 is installed in the housing, both ends of the electrode assembly 2 maintain an appropriate distance from the cover plate assembly 3, guaranteeing that the tabs on both sides of the electrode assembly 2 can be bent normally after installation, and the bent tabs connect to the electrode posts on the cover plate assembly 3; simultaneously The appropriate spacing between the end of electrode assembly 2 and cover plate assembly 3 prevents excessive spacing and effectively prevents electrode assembly 2 from shaking relative to housing 1 after being installed in the housing, ensuring the battery can pass vibration testing and preventing electrode tab tearing after vibration testing. The height between the inner surface of the bottom wall and the inner surface of the top wall of housing 1 meets the height requirement of the negative electrode plate 203. In the vertical direction, the distance between the upper and lower ends of the electrode assembly 2 and the inner wall of the housing 1 is moderate to prevent the negative electrode 203 from being too large, which could cause interference between the electrode assembly 2 and the housing 1 when it is inserted into the housing. This would prevent the electrode assembly 2 from being inserted into the housing, or cause the inner wall of the housing 1 to rub against and damage the inner insulating film 6 and the diaphragm 202 outside the electrode assembly 2, resulting in a short circuit risk between the electrodes of the electrode assembly 2 or a short circuit when the electrode assembly 2 contacts the housing 1. At the same time, In the vertical direction, the distance between the upper and lower ends of the electrode assembly 2 and the inner wall of the housing 1 is moderate to prevent the distance from being too large, ensuring that the electrode assembly 2 can be stably held in the housing 1 after being inserted into the housing, and preventing the electrode tabs from tearing during vibration testing. In addition, the distance between the electrode assembly 2 and the housing 1 and the cover plate assembly 3 is moderate to prevent the housing 1 or the cover plate assembly 3 from damaging the negative electrode sheet 203, ensuring the area of ​​the negative electrode sheet 203, and preventing lithium plating.

[0042] The battery also includes a cover assembly 3, which is disposed on the openings at both ends of the housing; the cover assembly 3 includes a terminal post, and the electrode tabs on both sides of the electrode group 2 in the length direction are electrically connected to the terminal post.

[0043] Optionally, in one embodiment, as shown in FIG1, the outer edge of the negative electrode 203 extends beyond the outer edge of the positive electrode 201. In this embodiment, the outer edge of the negative electrode 203 extends beyond the outer edge of the positive electrode 201, and the size of the negative electrode 203 is larger than that of the positive electrode 201. When the housing 1 or the cover assembly 3 contacts the electrode group 2, it first presses against the separator 202, and then squeezes the negative electrode 203. After the separator 202 is squeezed, it contacts the negative electrode 203. If the housing 1 or the cover assembly 3 continues to squeeze the negative electrode 203, the negative electrode 203 may puncture the separator 202, leading to a short circuit risk in the electrode group 2. The length of the housing 1 and the length of the negative electrode 203 satisfy the following condition: After electrode assembly 2 is installed in the casing, there is a certain distance between its two ends in the length direction and the two ends in the length direction of casing 1. After the cover assembly 3 is installed, there is an appropriate distance between the inner side of the cover assembly 3 and the end face of electrode assembly 2. This distance can accommodate the bent electrode tabs. The electrode tabs will not squeeze the installation space of the cover assembly 3. The cover assembly 3 can be easily and quickly installed on the opening of casing 1, which can improve the assembly efficiency of the battery. At the same time, there is a certain distance between the two ends in the length direction of electrode assembly 2 and the two ends in the length direction of casing 1, which can prevent the cover assembly 3 from damaging the negative electrode sheet 203, prevent damage to the negative electrode sheet 203, and reduce the risk of lithium plating. In addition, it can also prevent damage to the separator 202 and ensure the insulation effect of the separator 202.

[0044] Furthermore, in this embodiment, To further optimize the difference between the length of the housing 1 and the length of the negative electrode 203, damage to the negative electrode 203 and the separator 202 is prevented, ensuring that the tabs can be bent normally, the tabs can be connected to the terminals, and the cover assembly 3 can be installed normally. At the same time, the difference between the length of the housing 1 and the length of the negative electrode 203 is moderate. Under the premise of ensuring the installation and protection of the negative electrode 203, the difference between the length of the negative electrode 203 and the housing 1 is minimized as much as possible, thereby increasing the length of the negative electrode 203 and thus increasing the energy density of the battery.

[0045] As shown in Figure 2, in other embodiments, as another arrangement, the outer edge of one side of the positive electrode 201 along its length extends beyond the outer edge of the negative electrode 203; the other sides of the positive electrode 201 are all located inside the negative electrode 203. In this embodiment, the outer edge of one side of the positive electrode 201 extends beyond the outer edge of the negative electrode 203 along its length. After the electrode assembly 2 is installed in the housing, the cover plate assembly 3 cannot press down on the positive electrode 201 and the negative electrode 203. Therefore, the difference between the length of the housing 1 and the length of the negative electrode 203 should be greater than the difference between the length of the housing 1 and the length of the negative electrode 203 when the positive electrode 201 is recessed within the negative electrode 203. To ensure that the cover plate assembly 3 does not press down on the positive electrode 201 and the negative electrode 203 after installation, L and L1 must satisfy... Ensure that the negative electrode 203 has sufficient and appropriate spacing from both ends of the housing 1 to accommodate the bent electrode tabs and ensure the installation of the cover plate assembly 3.

[0046] Furthermore, in this embodiment, To further optimize the length difference between the housing 1 and the negative electrode 203, while ensuring the installation of the cover plate assembly 3 and protecting the negative electrode 203 and the separator 202, the length difference between the negative electrode 203 and the housing 1 is minimized as much as possible, thereby improving the energy density of the battery.

[0047] As shown in Figure 2, in one embodiment, the distance by which the outer edge of one side of the positive electrode 201 extends beyond the outer edge of the negative electrode 203 along its length is d, where 1mm ≤ d ≤ 5mm. The value of d is moderate, which helps to ensure the alignment of the overall structure after stacking.

[0048] As shown in Figure 2, an insulating layer is provided on the side of the positive electrode 201 that extends beyond the outer edge of the negative electrode 203. If the separator 202 on the side of the positive electrode 201 with the insulating layer is damaged, the insulating layer can isolate the positive electrode 201 and the negative electrode 203, preventing a short circuit between them and effectively ensuring the safety performance of the battery.

[0049] If the insulating layer is placed on the negative electrode 203, the area of ​​the active region of the negative electrode 203 will be reduced. To prevent lithium plating, the area of ​​the active region of the negative electrode 203 needs to be larger than the area of ​​the active region of the positive electrode 201. Therefore, placing the insulating layer on the negative electrode 203 would require a corresponding increase in the area of ​​the negative electrode 203; otherwise, lithium plating would easily occur. This solution places the insulating layer on the positive electrode 201, achieving insulation between the positive and negative electrode 201 without increasing the area of ​​the negative electrode 203, thus improving the insulation protection effect.

[0050] As shown in Figure 2, in one embodiment, the positive electrode 201 has a positive tab 2011 at its left end, and the negative electrode 203 has a negative tab 2031 at its right end. The left edge of the positive electrode 201 extends beyond the left edge of the negative electrode 203, and an insulating layer is disposed on the left outer edge of the positive electrode 201. The insulating layer extends inward into the left edge of the negative electrode 203 by a certain distance to ensure the insulating and protective effect of the insulating layer.

[0051] For example, the left edge of the positive electrode 201 extends 1 mm beyond the left edge of the negative electrode 203, and an insulating layer is provided on the area of ​​the positive electrode 201 between the left edge of the negative electrode 203 and the left edge of the positive electrode 201.

[0052] Alternatively, the insulating layer can be made of ceramic or organic polymer insulating material.

[0053] In other embodiments, to prevent lithium plating, provided that the area of ​​the negative electrode 203 is larger than the area of ​​the positive electrode 201, the right edge of the positive electrode 201 may extend beyond the right edge of the negative electrode 203; or the left edge of the positive electrode 201 may extend beyond the left edge of the negative electrode 203, while the right edge of the positive electrode 201 may extend beyond the right edge of the negative electrode 203.

[0054] In other embodiments, a positive electrode tab 2011 is provided on the right side of the positive electrode 201, and a negative electrode tab 2031 is provided on the left side of the negative electrode 203.

[0055] In one embodiment, as shown in Figures 6 and 12, the battery further includes a pressure relief mechanism 5, which is disposed on the cover plate assembly 3. When the battery is depressurized, hot gas is transferred from the electrode assembly 2 to the depressurization mechanisms 5 at both ends. A support member 4 needs to be provided between the bottom of the electrode assembly 2 and the bottom wall of the housing 1. The support member 4 supports the bottom of the electrode assembly 2 to separate the bottom of the electrode assembly 2 from the bottom wall of the housing 1, forming an exhaust channel. In this embodiment, the height of the support member 4 provided between the housing 1 and the electrode assembly 2 can be appropriately reduced. Therefore, the height difference between the inner wall of the housing 1 and the electrode assembly 2 can be appropriately reduced. To prevent interference between electrode assembly 2 and housing 1 in the height direction during insertion, ensure smooth insertion of electrode assembly 2 into the housing, and prevent damage to diaphragm 202 and negative electrode 203.

[0056] As shown in Figure 7, in one embodiment, the battery further includes an inner insulating film 6 and an outer insulating film 7. The inner insulating film 6 wraps around the electrode assembly 2, and has openings at both ends along its length to allow the positive electrode tab 2011 and the negative electrode tab 2031 to extend out. The inner insulating film 6 provides insulation between the electrode assembly 2 and the inner wall of the casing 1, preventing a short circuit after the electrode assembly 2 comes into contact with the metal casing 1. The outer insulating film 7 wraps around the casing 1 to improve the battery's insulation effect and prevent short circuits or leakage.

[0057] The height H between the inner wall surface of the bottom wall and the inner wall surface of the top wall of the housing 1 is the inner height of the housing 1. Under the premise that the outer edge of the negative electrode 203 exceeds the outer edge of the positive electrode 201, housings 1 with different lengths and inner heights are designed, as well as electrode groups 2 corresponding to housings 1 with different lengths and inner heights. The battery is assembled first. After the battery is assembled, a short vibration test is carried out on the battery. After the vibration test, a CT (computed tomography) scan is carried out on the electrode tab. The test results are shown in Table 1 and Table 2.

[0058] Table 1 (The outer edge of the negative electrode extends beyond the outer edge of the positive electrode)

[0059] Table 2 (The outer edge of the negative electrode extends beyond the outer edge of the positive electrode)

[0060] As can be seen from Example 1, when the outer edge of the negative electrode extends beyond the outer edge of the positive electrode, When the content is less than 0.96%, one side of the electrode cannot be bent, and the cover plate cannot be welded to the shell; as can be seen from Examples 2 to 16, when At that time, there were no problems with the insertion of electrode assembly 2 into the housing; no damage was found to the inner insulating film 6; there were no problems with the welding of the cover plate assembly 3 to the housing 1; after vibration, CT testing did not find any tearing of the electrode tabs; as can be seen from Example 17, when During the test, due to the excessive distance between the two ends of the pole group 2 in the length direction and the cover plate assembly 3, the pole group 2 was prone to shaking after being installed in the housing, and the pole tabs tore after the vibration test.

[0061] The height H between the inner wall surface of the bottom wall and the inner wall surface of the top wall of the housing 1 is the inner height of the housing 1. Under the premise that the outer edge of one side of the positive electrode extends beyond the outer edge of the negative electrode, housings 1 with different lengths and inner heights are designed, as well as electrode groups 2 corresponding to housings 1 with different lengths and inner heights are designed. The battery is assembled first. After the battery assembly is completed, a short vibration test is carried out on the battery. After the vibration test, CT detection is carried out on the tabs. The test results are shown in Tables 3 and 4.

[0062] Table 3 (The outer edge of one side of the positive electrode extends beyond the outer edge of the negative electrode along its length)

[0063] Table 4 (The outer edge of one side of the positive electrode extends beyond the outer edge of the negative electrode along its length)

[0064] As can be seen from Example 18, when the outer edge of one side of the positive electrode extends beyond the outer edge of the negative electrode along its length, when... When the content is less than 1.04%, one side of the electrode cannot be bent, and the cover plate cannot be welded to the shell; as can be seen from Examples 19 to 35, when At that time, there were no problems with the insertion of electrode assembly 2 into the housing; the inner insulating film 6 was not damaged; the welding of cover plate assembly 3 to housing 1 was not problematic; after vibration, CT testing did not reveal any tearing of the electrode tabs; as can be seen from Example 36, when When the value is greater than 13.33%, the distance between the two ends of the pole group 2 and the cover plate assembly 3 in the length direction is too large, and the pole group 2 is prone to shaking after entering the shell, and the pole tabs tear after the vibration test.

[0065] As shown in Figures 9, 10, and 11, in other embodiments, the battery further includes a pressure relief mechanism 5, which is disposed on the bottom wall of the housing 1. Compared to the pressure relief mechanism 5 being located on the cover assembly 3, the battery relieves pressure through the pressure relief mechanism 5 located at the bottom of the electrode group 2, which can reduce the pressure relief path and improve the pressure relief efficiency. In this embodiment, a support member 4 needs to be provided between the bottom of the electrode group 2 and the bottom wall of the housing 1. The support member 4 supports the bottom of the electrode group 2 to separate the bottom of the electrode group 2 from the bottom wall of the housing 1, forming an exhaust channel. This facilitates the flow of hot air to the exhaust channel at the bottom of the housing 1, and then through the exhaust channel to the pressure relief mechanism 5 for discharge. Therefore, in this embodiment, sufficient space needs to be reserved at the bottom of the housing 1 to accommodate the support member 4. This allows for the placement of a support 4 at the bottom of electrode assembly 2, preventing the negative electrode sheet 203 from being too high and avoiding interference with the casing 1 during installation. This ensures smooth installation of electrode assembly 2 and improves battery assembly efficiency. This prevents the housing 1 from interfering with the friction electrode assembly 2 during insertion, prevents damage to the diaphragm 202, and ensures the insulation effect of the diaphragm 202; simultaneously, To prevent the distance between electrode assembly 2 and the inner wall of housing 1 from being too large after electrode assembly 2 is inserted into the housing, to ensure that electrode assembly 2 is stably kept in housing 1, to ensure that the battery can pass the vibration test, and to prevent damage or tearing of the electrode tabs.

[0066] Furthermore, To further optimize the distance between the pole group 2 and the inner wall of the housing 1.

[0067] As shown in Figure 11, in this embodiment, the bottom of the housing 1 can be provided with one or more pressure relief mechanisms 5. The number of pressure relief mechanisms 5 can be flexibly adjusted according to the length of the battery. When the overall length of the battery is long, two or more pressure relief mechanisms 5 are provided at the bottom of the housing 1 to ensure the pressure relief effect; when the battery length is short, one pressure relief mechanism 5 can be provided at the bottom of the housing 1.

[0068] With the pressure relief mechanism 5 located at the bottom of the housing 1, housings 1 with different lengths and inner heights are designed, as well as electrode groups 2 corresponding to housings 1 with different lengths and inner heights. The battery is assembled first, and after the battery assembly is completed, a short vibration test is carried out on the battery. After the vibration test, a CT test is carried out on the electrode tabs. The test results are shown in Tables 5 and 6.

[0069] Table 5 (Pressure relief mechanism is located at the bottom of the housing)

[0070] Table 6 (Pressure relief mechanism is located at the bottom of the housing)

[0071] When the pressure relief mechanism is located at the bottom of the housing, as can be seen from Example 37, when When the content is less than 1%, interference occurs when the electrode assembly enters the casing, resulting in damage to the inner insulation and a risk of diaphragm damage. As can be seen from Examples 38 to 52, when... At that time, there were no problems with the insertion of electrode assembly 2 into the housing; the inner insulating film 6 was not damaged; the welding between the cover plate assembly 3 and the housing 1 was not problematic; after vibration, CT testing did not reveal any tearing of the electrode tabs; as can be seen from Example 53, when When the value is greater than 12.5%, the electrode assembly 2 is prone to shaking after being inserted into the shell due to the large distance between the upper and lower ends of the electrode assembly 2 and the inner wall of the shell 1. After the vibration test, the electrode tabs are torn.

[0072] With the pressure relief mechanism 5 installed on the cover plate assembly, housings 1 with different lengths and inner heights are designed, as well as electrode groups 2 corresponding to housings 1 with different lengths and inner heights. The battery is assembled first. After the battery assembly is completed, a short vibration test is carried out on the battery. After the vibration test, a CT test is carried out on the electrode tabs. The test results are shown in Tables 7 and 8.

[0073] Table 7 (Pressure relief mechanism is installed on the cover plate assembly)

[0074] Table 8 (Pressure relief mechanism is installed on the cover plate assembly)

[0075] As can be seen from Example 54, when the pressure relief mechanism is located at the bottom of the housing, when... When the content is less than 0.67%, interference occurs when the electrode assembly enters the casing, the inner insulation is damaged, and there is a risk of diaphragm damage; as can be seen from Examples 55 to 69, when At that time, there were no problems with the insertion of electrode assembly 2 into the housing; no damage was found to the inner insulating film 6; there were no problems with the welding of the cover plate assembly 3 to the housing 1; after vibration, CT testing did not find any tearing of the electrode tabs; as can be seen from Example 70, when When the value is greater than 12.5%, the electrode assembly 2 is prone to shaking after being inserted into the shell due to the large distance between the upper and lower ends of the electrode assembly 2 and the inner wall of the shell 1. After the vibration test, the electrode tabs are torn.

[0076] Optionally, in one embodiment, the pressure relief mechanism 5 includes an explosion-proof valve. The housing 1 or cover assembly 3 has mounting holes, and the explosion-proof valve is installed within these mounting holes.

[0077] The length of the shell is L, 300mm≤L≤1200mm, and the height between the inner surface of the bottom wall and the inner surface of the top wall of the shell is H, 80mm≤H≤300mm.

[0078] Alternatively, in one embodiment, the battery includes a blade battery.

[0079] According to an embodiment of this application, another aspect provides a battery module including the battery described above.

[0080] After the electrode assembly 2 is installed in the battery module, the two ends of the electrode assembly 2 are kept at an appropriate distance from the cover plate assembly 3. This ensures that the tabs on both sides of the electrode assembly 2 can be bent normally after the electrode assembly 2 is installed in the casing, and the bent tabs are connected to the terminal posts on the cover plate assembly 3. At the same time, it can prevent the distance between the two from being too large, effectively prevent the electrode assembly 2 from shaking relative to the casing 1 after it is installed in the casing, ensure that the battery can pass the vibration test, and prevent the tabs from tearing after the vibration test.

[0081] According to an embodiment of this application, in another aspect, a battery pack is also provided, including the battery module described above.

[0082] Although embodiments of this application have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of this application, and all such modifications and variations fall within the scope defined by the appended claims.

Claims

1. A battery, characterized in that, include: The shell has openings at both ends along its length; the length of the shell is L, and the height between the inner surface of the bottom wall and the inner surface of the top wall of the shell is H. An electrode assembly is disposed within the housing. The electrode assembly includes a positive electrode plate, a separator, and a negative electrode plate stacked together. The area of ​​the negative electrode plate is larger than the area of ​​the positive electrode plate. The outer edge of the separator extends beyond the outer edges of both the positive and negative electrode plates. The length of the negative electrode plate is L1, and the height of the negative electrode plate is H1.

2. The battery according to claim 1, characterized in that, The outer edge of the negative electrode extends beyond the outer edge of the positive electrode.

3. The battery according to claim 2, characterized in that, 4. The battery according to claim 1, characterized in that, The outer edge of one side of the positive electrode extends beyond the outer edge of the negative electrode along its length; the other sides of the positive electrode are located inside the negative electrode.

5. The battery according to claim 4, characterized in that, The distance by which the outer edge of one side of the positive electrode extends beyond the outer edge of the negative electrode in the longitudinal direction is d, where 1mm ≤ d ≤ 5mm.

6. The battery according to claim 4 or 5, characterized in that, An insulating layer is provided on the side of the positive electrode that extends beyond the outer edge of the negative electrode.

7. The battery according to any one of claims 1 to 5, characterized in that, It also includes a pressure relief mechanism, which is located on the bottom wall of the housing. And / or, the battery further includes a cover assembly disposed on the opening; the cover assembly includes a terminal post, and the tabs on both sides of the terminal group along the length direction are electrically connected to the terminal post.

8. The battery according to any one of claims 1 to 5, characterized in that, It also includes a pressure relief mechanism and a cover plate assembly, wherein the pressure relief mechanism is disposed on the cover plate assembly.

9. A battery module, characterized in that, The battery includes any one of claims 1 to 8.

10. A battery pack, characterized in that, Includes the battery module as described in claim 9.

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