Battery cell, battery, battery module, battery pack and power utilization device

Abstract

The utility model discloses a battery cell, a battery, a battery module, a battery pack and an electric device. The battery cell comprises a shell, the pole core is arranged in the shell, two ends of the pole core in the length direction are respectively a first end and a second end, and the first end is provided with a positive pole lug and a negative pole lug; and the separator is arranged in the shell, the separator is positioned between the second end of the pole core and the shell, and the separator is used for separating the pole core from the shell. According to the battery cell disclosed by the utility model, the pole core is separated from the shell through the separator, so that the pole core is protected, and the service life of the pole core is prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of vehicles, and in particular to a battery cell, a battery, a battery module, a battery pack and an electric device. Background Art

[0002] As the core component of power batteries, battery cells play a significant role in power batteries. For power batteries, battery cells determine the quality of power battery products, and of course, they also affect the battery life and capacity of the vehicle.

[0003] In the related art, a battery cell includes a positive electrode tab and a negative electrode tab. When the positive electrode tab and the negative electrode tab are located at the same end in the length direction of the battery cell, that is, the tabs are led out at the same end, the current of the battery cell does not need to pass through the shell, which can reduce the battery impedance. However, the end of the electrode core away from the positive electrode tab and the negative electrode tab is easily damaged, shortening the service life of the electrode core. Utility Model Content

[0004] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, one purpose of the utility model is to provide a battery core, which separates the pole core from the shell by a separator, thereby protecting the pole core and extending the service life of the pole core.

[0005] The second objective of the present invention is to provide a battery using the above-mentioned battery cell.

[0006] The third object of the present utility model is to provide a battery module using the above-mentioned battery.

[0007] The fourth objective of the present invention is to provide a battery pack using the above-mentioned battery or the above-mentioned battery module.

[0008] The fifth objective of the present utility model is to provide an electrical device using the above-mentioned battery pack.

[0009] The battery cell according to the first aspect of the present invention comprises: a shell; a pole core, the pole core is arranged in the shell, the two ends of the pole core in the length direction are respectively a first end and a second end, the first end is provided with a positive pole ear and a negative pole ear; a separator, the separator is arranged in the shell, the separator is located between the second end of the pole core and the shell, and the separator separates the pole core from the shell.

[0010] According to the battery cell of the utility model, the second end of the pole core is separated from the shell (e.g., the bottom wall of the shell) by providing a separator, and the separator has a protective effect on the pole core, which can prevent the pole core from being directly in contact with the shell and causing damage to the pole core, thereby extending the service life of the pole core and the battery cell. In addition, the separator is easy to install and operate, thereby improving the assembly efficiency of the battery cell. In addition, the positive pole ear and the negative pole ear are arranged at the first end of the battery cell, so that the current on the pole core cannot pass through the shell, reducing the structural impedance of the battery cell.

[0011] According to some embodiments of the present invention, at least one through hole is formed on the separator.

[0012] According to some embodiments of the present invention, a pressure relief device is provided on the housing, and the pressure relief device is configured to release the internal pressure of the battery cell.

[0013] According to some embodiments of the present utility model, the housing includes a shell and a bottom cover plate connected to each other, the separator separates the pole core from the bottom cover plate, and the pressure relief device is arranged on the bottom cover plate.

[0014] According to some embodiments of the present invention, at least a portion of the pressure relief device is opposite to the through hole along the thickness direction of the partition.

[0015] According to some embodiments of the present invention, the area where the projection of at least a portion of the pressure relief device on the partition along the thickness direction of the partition overlaps with the through hole is S1, and the cross-sectional area of ​​the pressure relief device along a plane perpendicular to the thickness direction of the partition is S2, wherein S1 and S2 satisfy: 50%≤S1 / S2≤100%.

[0016] According to some embodiments of the utility model, the cross-sectional area of ​​the through hole along a plane perpendicular to the thickness direction of the separator is S3, and the cross-sectional area of ​​the separator along a plane perpendicular to the thickness direction of the separator is S4, wherein S3 and S4 satisfy: 30%≤S3 / S4≤80%.

[0017] According to some embodiments of the utility model, there are multiple through holes, and the multiple through holes constitute at least one first through hole group and at least one second through hole group, the first through hole group includes multiple first through holes, and the multiple first through holes are arranged at radial intervals along the partition, the second through hole group includes multiple second through holes, and the multiple second through holes are arranged at circumferential intervals along the partition, and the multiple second through holes and the multiple first through holes are spaced apart from each other.

[0018] According to some embodiments of the present invention, a cross-sectional area of ​​the second through hole along a plane perpendicular to the thickness direction of the partition is larger than a cross-sectional area of ​​the first through hole along a plane perpendicular to the thickness direction of the partition.

[0019] According to some embodiments of the present invention, the cross-sectional areas of the plurality of first through holes along a plane perpendicular to the thickness direction of the partition are the same; or, the cross-sectional areas of at least two of the plurality of first through holes along a plane perpendicular to the thickness direction of the partition are different.

[0020] According to some embodiments of the present invention, there are multiple groups of the first through hole groups, and the multiple groups of the first through hole groups are arranged at intervals along the circumference of the separator, and the second through hole is located between two adjacent groups of the first through hole groups.

[0021] According to some embodiments of the present invention, the minimum distance between any second through hole and the first through hole of the adjacent first through hole group adjacent to the edge of the separator is l1, wherein l1 satisfies: 0.5mm≤l1≤3mm; and / or the minimum distance between two adjacent first through holes of the first through hole group adjacent to the edge of the separator is l2, wherein l2 satisfies: 0.5mm≤l2≤3mm.

[0022] According to some embodiments of the present invention, the thickness of the separator is h, wherein h satisfies: 0.3mm≤h≤2mm.

[0023] According to some embodiments of the present invention, the separator is a polyethylene terephthalate piece or a polypropylene piece.

[0024] A battery according to an embodiment of the second aspect of the utility model includes a battery cell according to an embodiment of the first aspect of the utility model.

[0025] A battery module according to an embodiment of the third aspect of the utility model includes a battery according to an embodiment of the second aspect of the utility model.

[0026] The battery pack according to the fourth aspect of the present invention comprises the battery according to the second aspect of the present invention or the battery module according to the third aspect of the present invention.

[0027] The electrical device according to the fifth aspect of the present invention comprises a battery pack according to the fourth aspect of the present invention.

[0028] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0030] Figure 1 is a schematic diagram of a battery cell according to an embodiment of the utility model;

[0031] Figure 2 is an exploded view of a battery cell according to an embodiment of the utility model;

[0032] Figure 3 is a schematic diagram of a separator of a battery cell according to an embodiment of the utility model;

[0033] Figure 4 is a schematic diagram of a battery cell according to an embodiment of the utility model from another angle;

[0034] Figure 5 is an exploded view of a battery cell according to an embodiment of the utility model from another angle;

[0035] Figure 6 It is a schematic diagram of the assembly of the separator and the pressure relief device of the battery cell according to the embodiment of the utility model;

[0036] Figure 7 is a schematic diagram of the assembly of a separator and a pressure relief device of a battery cell according to another embodiment of the utility model;

[0037] Figure 8 It is a schematic diagram of the assembly of a separator and a pressure relief device of a battery cell according to another embodiment of the utility model.

[0038] Reference numerals:

[0039] 100. Battery cell;

[0040] 1. Shell; 11. Pressure relief device; 120 shell; 12. Bottom cover plate;

[0041] 121, reinforcing ribs; 13, protective parts;

[0042] 2. Pole core; 21. First end; 211. Positive pole ear; 212. Negative pole ear; 22. Second end;

[0043] 3. separator; 31. through hole; 32. first through hole group; 321. first through hole;

[0044] 33. Second through hole group; 331. Second through hole. DETAILED DESCRIPTION

[0045] The embodiments of the present invention are described in detail below. The embodiments described with reference to the accompanying drawings are exemplary. Figure 1-Figure 8 A battery cell 100 according to an embodiment of the first aspect of the present utility model is described.

[0046] like Figure 1 and Figure 2 As shown, the battery cell 100 according to the first embodiment of the utility model includes a shell 1, a pole core 2 and a separator 3.

[0047] Specifically, the pole core 2 and the separator 3 are both arranged in the housing 1, and the length direction of the pole core 2 (for example, Figure 1 The two ends of the core 2 (in the up and down direction indicated by the arrow in the middle) are respectively a first end 21 and a second end 22, the first end 21 is provided with a positive electrode tab 211 and a negative electrode tab 212, the separator 3 is located between the second end 22 of the core 2 and the housing 1, and the separator 3 separates the core 2 from the housing 1. For example, in Figure 1 and Figure 2 In the example, the upper end of the pole core 2 is the first end 21, and the lower end of the pole core 2 is the second end 22, that is, the separator 3 is located between the lower surface of the second end 22 of the pole core 2 and the bottom wall of the shell 1, and the pole core 2 is separated from the inner wall of the shell 1 by the separator 3.

[0048] With such a configuration, the battery cell 100 is led out at the same end, and the current of the battery cell 100 does not need to pass through the outer shell 1, which can reduce the structural impedance. Moreover, the battery cell 100 can be provided with an exhaust structure at only one end (such as the second end 22 mentioned above), thereby helping to improve the space utilization of the battery cell 100. In addition, the second end 22 of the pole core 2 is separated from the outer shell 1 by the separator 3, and the second end 22 of the pole core 2 does not contact the bottom wall of the outer shell 1. The separator 3 has a protective effect on the pole core 2, which can prevent the pole core 2 from being directly in contact with the outer shell 1 and causing damage to the pole core 2, thereby extending the service life of the pole core 2, and then extending the service life of the battery cell 100. In addition, the separator 3 is easy to install and operate, and the separator 3 can be placed in the outer shell 1, thereby improving the assembly efficiency of the battery cell 100.

[0049] According to the battery cell 100 of the utility model, the second end 22 of the pole core 2 is separated from the shell 1 (e.g., the bottom wall of the shell 1) by providing a separator 3, and the separator 3 has a protective effect on the pole core 2, which can prevent the pole core 2 from being directly in contact with the shell 1 and causing damage to the pole core 2, thereby extending the service life of the pole core 2 and the battery cell 100. In addition, the separator 3 is easy to install and operate, thereby improving the assembly efficiency of the battery cell 100. In addition, the positive pole tab 211 and the negative pole tab 212 are provided at the first end 21 of the battery cell 100, so that the current on the pole core 2 cannot pass through the shell 1, reducing the structural impedance of the battery cell 100.

[0050] According to some embodiments of the present invention, referring to Figure 3 , at least one through hole 31 is formed on the separator 3. For example, Figure 3 In the example of FIG. 1 , the through hole 31 is formed along the thickness direction of the separator 3 (eg, Figure 3 The through hole 31 (in the up and down direction indicated by the arrow in the middle) penetrates the separator 3. In this way, the electrolyte can be stored in the through hole 31, thereby increasing the storage space of the electrolyte, thereby reducing the risk of electrolyte overflow and avoiding damage to the battery cell 100.

[0051] According to some embodiments of the present invention, referring to Figure 4 and Figure 5 The housing 1 is provided with a pressure relief device 11, which is configured to release the internal pressure of the battery cell 100. In this way, when the pressure or temperature inside the battery cell 100 reaches a threshold, the gas inside the battery cell 100 can be released through the pressure relief device 11 to release the pressure inside the battery cell 100, so as to facilitate the normal use of the battery cell 100.

[0052] According to some embodiments of the present invention, referring to Figure 5 The housing 1 includes a shell 120 and a bottom cover plate 12 connected to each other, a separator 3 separates the pole core 2 from the bottom cover plate 12, and a pressure relief device 11 is arranged on the bottom cover plate 12. Figure 5 In the example, the bottom cover plate 12 is located at the lower end of the shell 120, the bottom cover plate 12 is connected to the shell 120 by welding, and the pressure relief device 11 is arranged on the side wall of the bottom cover plate 12 away from the partition 3. Thus, by setting the shell 1 in a split manner, the processing accuracy of the shell 120 and the bottom cover plate 12 is improved, thereby improving the processing accuracy of the shell 1. Exemplarily, the pressure relief device 11 is arranged on the bottom cover plate 12 of the shell 120, and the pressure relief device 11 and the bottom cover plate 12 can be an integrally formed structure or a separately arranged structure. For example, the pressure relief device 11 is an area on the bottom cover plate 12 where a weak structure is formed, such as the pressure relief device 11 is an area on the bottom cover plate 12 where a notched groove is arranged. Of course, the pressure relief device 11 and the bottom cover plate 12 can also be a split structure, and the pressure relief device 11 can be connected to the bottom cover plate 12 by welding or the like. Correspondingly, the pressure relief device 11 can be one of the components such as an explosion-proof valve, an explosion-proof disk, an air valve, a pressure relief valve or a safety valve. It should be noted that the pressure relief device 11 may also be disposed on the housing 120 to achieve pressure relief inside the battery cell 100 .

[0053] According to some embodiments of the present invention, referring to Figure 5 and Figure 6 , at least a portion of the pressure relief device 11 is opposite to the through hole 31 along the thickness direction of the partition 3. For example, Figure 5 and Figure 6In the example, at least a portion of the pressure relief device 11 is connected to the through hole 31. In this way, the through hole 31 has the function of an exhaust channel. When the pressure inside the battery cell 100 is too high, the gas inside the battery cell 100 can flow through the through hole 31 to the pressure relief device 11 and then be discharged to the outside of the battery cell 100, which is beneficial to the pressure relief of the battery cell 100 and the smooth opening of the pressure relief device 11, thereby improving the safety of the battery cell 100.

[0054] Optionally, the area where the projection of at least a portion of the pressure relief device 11 on the separator 3 along the thickness direction of the separator 3 overlaps with the through hole 31 is S1 (that is, the area of ​​the pressure relief device 11 opposite to the through hole 31 along the thickness direction of the separator 3), and the cross-sectional area of ​​the pressure relief device 11 along a plane perpendicular to the thickness direction of the separator (that is, the cross-sectional area of ​​the pressure relief device 11 along the vertical direction) is S2, wherein S1 and S2 satisfy: 50%≤S1 / S2≤100%. For example, when the ratio S1 / S2 of the area S1 where at least a portion of the pressure relief device 11 is opposite to the through hole 31 along the thickness direction of the separator 3 to the cross-sectional area S2 of the pressure relief device 11 is less than 50%, the cross-sectional area of ​​the exhaust channel of the pressure relief device 11 is small, so that after the pressure relief device 11 is turned on, the amount of gas flowing through the exhaust channel of the pressure relief device 11 per unit time is small, thereby reducing the exhaust speed of the battery cell 100, which is not conducive to the pressure relief of the battery cell 100. Therefore, by setting the area S1 where at least a portion of the pressure relief device 11 is opposite to the through hole 31 along the thickness direction of the separator 3 and the cross-sectional area S2 of the pressure relief device 11 to satisfy 50%≤S1 / S2≤100%, the pressure relief capacity of the pressure relief device 11 is effectively guaranteed, and the pressure relief area of ​​the battery cell 100 is guaranteed. Therefore, after the pressure relief device 11 is turned on, the amount of gas flowing through the exhaust channel of the pressure relief device 11 per unit time is relatively large, thereby increasing the exhaust speed of the battery cell 100 and improving the safety of the battery cell 100.

[0055] According to some embodiments of the utility model, the cross-sectional area of ​​the through hole 31 along the plane perpendicular to the thickness direction of the separator 3 is S3, and the cross-sectional area of ​​the separator 3 along the plane perpendicular to the thickness direction of the separator 3 is S4, wherein S3 and S4 satisfy: 30%≤S3 / S4≤80%. For example, when the ratio S3 / S4 of the cross-sectional area S3 of the through hole 31 along the plane perpendicular to the thickness direction of the separator 3 to the cross-sectional area S4 of the separator 3 along the plane perpendicular to the thickness direction of the separator 3 is less than 30%, the cross-sectional area of ​​the through hole 31 is small, so that the storage space of the electrolyte is small, which makes it easy for the electrolyte to overflow during injection, and the battery cell 100 is easily damaged. In addition, the through hole 31 is small, which is not convenient for injecting the battery cell 100. When the ratio S3 / S4 of the cross-sectional area S3 of the through hole 31 along the plane perpendicular to the thickness direction of the separator 3 to the cross-sectional area S4 of the separator 3 along the plane perpendicular to the thickness direction of the separator 3 is greater than 80%, the space occupied by the through hole 31 on the separator 3 is large, which reduces the structural strength of the separator 3 and is not conducive to the long-term use of the separator 3. Therefore, by setting the cross-sectional area S3 of the through hole 31 along the plane perpendicular to the thickness direction of the separator 3 and the cross-sectional area S4 of the separator 3 along the plane perpendicular to the thickness direction of the separator 3 to meet 30%≤S3 / S4≤80%, it is beneficial to increase the storage space of the electrolyte, reduce the risk of electrolyte overflow, and thus avoid damage to the battery cell 100. In addition, the structural strength of the separator 3 is guaranteed, thereby improving the protective effect of the separator 3 on the pole core 2, thereby extending the service life of the battery cell 100.

[0056] According to some embodiments of the present invention, referring to Figure 3 and Figure 6-Figure 8 There are multiple through holes 31. In the description of the present utility model, "multiple" means two or more. The multiple through holes 31 constitute at least one first through hole group 32 and at least one second through hole group 33. The first through hole group 32 includes multiple first through holes 321, which are arranged at intervals along the radial direction of the partition 3. The second through hole group 33 includes multiple second through holes 331, which are arranged at intervals along the circumferential direction of the partition 3. The multiple second through holes 331 and the multiple first through holes 321 are spaced apart from each other.

[0057] For example, in Figure 3 and Figure 6-Figure 8In the example, the second through hole group 33 includes four second through holes 331, and the four second through holes 331 are arranged at intervals along the circumference of the separator 3, the first through hole group 32 and the second through hole group 33 are arranged at intervals from each other, and a plurality of first through holes 321 are arranged between two adjacent second through holes 331. In this way, the number and arrangement of the through holes 31 are moderate, which further increases the storage space of the electrolyte, thereby further avoiding electrolyte overflow and thus avoiding damage to the battery cell 100. In addition, the material consumption of the separator 3 is reduced, thereby reducing the production cost of the separator 3, and also reducing the weight of the separator 3, thereby reducing the weight of the battery cell 100. In addition, it is convenient for at least one of the multiple through holes 31 to be opposite to the pressure relief device 11, which not only ensures the communication between the through hole 31 and the pressure relief device 11, improves the smoothness of gas discharge, but also facilitates the assembly of the separator 3 (that is, after the separator 3 rotates along the central axis of the separator 3, the through hole 31 can still be ensured to be opposite to the pressure relief device 11). Moreover, the layout of the first through hole group 33 and the second through hole group 33 is reasonable, which can improve the structural strength of the separator 3 while ensuring the normal use of the separator 3, thereby improving the stability of the separator 3 in long-term use and also improving the aesthetics of the separator 3. It should be noted that the number and arrangement of the first through holes 321, as well as the number and arrangement of the second through holes 331 can be specifically set according to actual use to better meet practical applications. For example, referring to Figure 7 and Figure 8 , which is a schematic diagram of the separator 3 relative to the pressure relief device 11 in different states after rotation.

[0058] According to some embodiments of the present invention, referring to Figure 6 , the cross-sectional area of ​​the second through hole 331 along a plane perpendicular to the thickness direction of the separator 3 is greater than the cross-sectional area of ​​the first through hole 321 along a plane perpendicular to the thickness direction of the separator 3. Figure 6 In the example, the first through hole 321 can be set in a circular shape, the second through hole 331 can be set in a polygonal shape, and the second through hole 331 bends and extends along the circumference of the separator 3. In this way, when the separator 3 is assembled with the shell 1, the separator 3 can be placed at any angle along the circumference of the separator 3, that is, when the separator 3 is rotated relative to the shell 1, the second through hole 331 can be opposite to the pressure relief device 11, which is beneficial to the pressure relief of the battery cell 100, effectively ensuring the normal use of the pressure relief device 11, and further improving the safety of the battery cell 100. In addition, the aesthetics of the separator 3 is improved. Moreover, the first through hole 321 and the second through hole 331 have a simple structure and are easy to produce and process, which is beneficial to the mass production of the separator 3. It should be noted that the shapes of the first through hole 321 and the second through hole 331 can be specifically set according to actual usage conditions to better meet practical applications.

[0059] According to some embodiments of the present invention, referring to Figure 6 The cross-sectional areas of the plurality of first through holes 321 along a plane perpendicular to the thickness direction of the separator 3 are all the same. Thus, the balance of the separator 3 is improved, thereby improving the stability of the separator 3 after installation, simplifying the structure of the separator 3, and facilitating mass production of the separator 3.

[0060] According to other embodiments of the present invention, Figure 6 , at least two of the multiple first through holes 321 have different cross-sectional areas along a plane perpendicular to the thickness direction of the separator 3. Therefore, while ensuring the structural strength of the separator 3, multiple first through holes 321 with different cross-sectional areas can be set to increase the cross-sectional areas of the multiple through holes 31, so that the first through holes 321 are opposite to the pressure relief device 11, and the storage space of the electrolyte is effectively increased. In addition, it is convenient to reasonably set the first through holes 321 according to the arrangement of the second through holes 331, so that the arrangement of the multiple first through holes 321 and the multiple second through holes 331 is more compact, thereby optimizing the space design of the separator 3.

[0061] According to some embodiments of the present invention, referring to Figure 3 and Figure 6 There are multiple first through hole groups 32, and the multiple first through hole groups 32 are arranged at intervals along the circumference of the separator 3, and the second through hole 331 is located between two adjacent first through hole groups 32. For example, Figure 3 and Figure 6 In the example, there are four groups of first through hole groups 32, and the four groups of first through hole groups 32 and the four second through holes 331 are arranged at intervals along the circumference of the separator 3, and the first through hole group 32 and the second through hole 331 are symmetrical along the center of the separator 3. In this way, through the joint action of multiple groups of first through hole groups 32, the weight of the separator 3 is further reduced, and the storage space of the electrolyte is further increased. In addition, the aesthetics of the separator 3 is improved, and the stability of the separator 3 is improved, so that the separator 3 can better protect the pole core 2, and it is also conducive to the mass production of the separator 3.

[0062] According to some embodiments of the present invention, referring to Figure 6, the minimum distance between any second through hole 331 and the first through hole 321 of the adjacent first through hole group 32 adjacent to the edge of the separator 3 is l1, where l1 satisfies: 0.5mm≤l1≤3mm. For example, when the minimum distance l1 between any second through hole 331 and the first through hole 321 of the adjacent first through hole group 32 adjacent to the edge of the separator 3 is less than 0.5mm, the distance between the second through hole 331 and the first through hole 321 of the adjacent first through hole group 32 adjacent to the edge of the separator 3 is relatively close, thereby reducing the structural strength of the separator 3, making the separator 3 easy to break, and thus shortening the service life of the separator 3. When the minimum distance l1 between any second through hole 331 and the first through hole 321 of the adjacent first through hole group 32 adjacent to the edge of the separator 3 is greater than 3mm, after the separator 3 is installed, the connection portion between any second through hole 331 and the first through hole 321 of the adjacent first through hole group 32 adjacent to the edge of the separator 3 is easy to block the pressure relief device 11, thereby affecting the exhaust of the pressure relief device 11, and further being detrimental to the normal use of the battery cell 100. Therefore, by setting the minimum distance l1 between any second through hole 331 and the first through hole 321 of the adjacent first through hole group 32 adjacent to the edge of the separator 3 to meet 0.5mm≤l1≤3mm, the layout of the first through hole 321 and the second through hole 331 is reasonable, the structural strength of the separator 3 is improved, thereby enhancing the protective effect of the separator 3 on the battery cell 100, and also extending the service life of the separator 3. In addition, it is beneficial for the through hole 31 to be opposite to the pressure relief device 11, thereby increasing the exhaust channel of the pressure relief device 11, so that the gas is smoothly discharged to the outside of the battery cell 100.

[0063] According to other embodiments of the present invention, Figure 6, the minimum distance between two adjacent first through holes 321 of the first through hole group 32 adjacent to the edge of the separator 3 is l2, where l2 satisfies: 0.5mm≤l2≤3mm. For example, when the minimum distance l2 between two adjacent first through holes 321 of the first through hole group 32 adjacent to the edge of the separator 3 is less than 0.5mm, the connection portion between two adjacent first through holes 321 of the first through hole group 32 adjacent to the edge of the separator 3 is narrow, thereby reducing the structural strength of the separator 3, making the separator 3 easy to break and damage, and thus shortening the service life of the separator 3. When the minimum distance l2 between two adjacent first through holes 321 of the first through hole group 32 adjacent to the edge of the separator 3 is greater than 3mm, after the separator 3 is installed, the connection portion between two adjacent first through holes 321 of the first through hole group 32 adjacent to the edge of the separator 3 has a large shielding area for the pressure relief device 11, which is easy to affect the exhaust of the pressure relief device 11, which is not conducive to the safe use of the battery cell 100. Therefore, by setting the minimum distance l2 between two adjacent first through holes 321 of the first through hole group 32 adjacent to the edge of the separator 3 to meet 0.5mm≤l2≤3mm, the distance between two adjacent first through holes 321 is moderate, which improves the structural strength of the separator 3 and is also conducive to the normal use of the separator 3. In addition, it is beneficial for the through hole 31 to be opposite to the pressure relief device 11, thereby increasing the exhaust channel of the pressure relief device 11, so that the gas is smoothly discharged to the outside of the battery cell 100.

[0064] According to some further embodiments of the utility model, the minimum distance between any second through hole 331 and the first through hole 321 of the adjacent first through hole group 32 adjacent to the edge of the separator 3 is l1, wherein l1 satisfies: 0.5mm≤l1≤3mm. At the same time, the minimum distance between two adjacent first through holes 321 of the adjacent edge of the separator 3 of the first through hole group 32 is l2, wherein l2 satisfies: 0.5mm≤l2≤3mm. Thus, the structural strength of the separator 3 is improved, thereby improving the protective effect of the separator 3 on the pole core 2 and extending the service life of the separator 3. In addition, the pressure relief device 11 is easily connected to the through hole 31, so that when the gas pressure inside the battery cell 100 is too high, the gas can be smoothly discharged through the through hole 31 and the pressure relief device 11, thereby improving the safety of the battery cell 100.

[0065] Further, refer to Figure 3, the thickness of the separator 3 is h, where h satisfies: 0.3mm≤h≤2mm. For example, when the thickness h of the separator 3 is less than 0.3mm, the spatial volume of the through hole 31 is small, so that the amount of electrolyte stored in the through hole 31 is small, which makes the electrolyte easy to overflow, causing the battery cell 100 to be easily damaged. When the thickness h of the separator 3 is greater than 2mm, the space occupied by the separator 3 in the outer shell 1 is large, which reduces the space utilization rate inside the outer shell 1. Therefore, by setting the thickness h of the separator 3 to satisfy 0.3mm≤h≤2mm, the storage space of the electrolyte is increased, thereby preventing the electrolyte from overflowing during injection, and also rationalizing the space occupied by the separator 3 in the outer shell 1, thereby improving the space utilization rate inside the outer shell 1.

[0066] According to some optional embodiments of the utility model, the separator 3 is a polyethylene terephthalate piece or a polypropylene piece. When the separator 3 is set to a polyethylene terephthalate piece, the polyethylene terephthalate piece has electrical insulation, thereby hindering the current on the pole core 2 from flowing to the housing 1, thereby reducing the structural impedance. When the separator 3 is set to a polypropylene piece, polypropylene also has electrical insulation, thereby reducing the structural impedance, and the material source is wide. In addition, polypropylene has high-strength mechanical properties and good high-wear processing properties, thereby improving the protective effect of the separator 3 on the pole core 2 and extending the service life of the separator 3. Optionally, the separator 3 is formed by injection molding. Thereby, the molding quality of the separator 3 is improved, and the production efficiency and processing accuracy of the separator 3 are also improved.

[0067] Further optionally, referring to Figure 5 , the pressure relief device 11 is welded to the housing 1, and a protective member 13 is provided on the side of the pressure relief device 11 away from the housing 1. Figure 5 In the example, the protective member 13 is opposite to the pressure relief device 11, and the protective member 13 is assembled with the housing 1. Such an arrangement increases the connection strength between the pressure relief device 11 and the housing 1, and prevents the pressure relief device 11 from falling off the housing 1. In addition, the protective member 13 can protect the pressure relief device 11, thereby extending the service life of the pressure relief device 11. For example, the protective member 13 is injection molded by polyester resin. As a result, the production and processing of the protective member 13 is facilitated, the processing efficiency of the protective member 13 is improved, and the structural strength of the protective member 13 is also improved, which is conducive to the long-term use of the protective member 13.

[0068] According to some optional embodiments of the utility model, the pressure relief device 11 is formed by stamping a separate pressure relief device 11 from steel and laser scoring the pressure relief device 11, and the detonation pressure is P, where P satisfies: 0.5Mpa≤P≤2Mpa. As a result, the production and processing efficiency of the pressure relief device 11 is high, and the processing accuracy is also high, thereby improving the assembly accuracy of the pressure relief device 11 and the housing 1, and is also conducive to the long-term use of the pressure relief device 11.

[0069] Optionally, the shell 120 is formed into a cylindrical shape by stamping steel or by winding and welding sheet materials, and the bottom cover plate 12 is reshaped by stamping steel, wherein the steel is corrosion-resistant. Thus, the connection strength between the bottom cover plate 12 and the circumferential side wall of the shell 120 is strengthened, thereby improving the structural strength of the shell 1, which is conducive to the long-term and stable use of the shell 1. In addition, the flatness of the bottom cover plate 12 is improved by stamping steel.

[0070] Further, refer to Figure 5 A reinforcing rib 121 is formed on the lower surface of the bottom cover plate 12. Figure 4 In the example of , the reinforcing rib 121 is formed by being recessed from the lower surface of the bottom cover plate 12 toward the upper surface of the bottom cover plate 12, and the reinforcing rib 121 is opposite to the installation position of the pressure relief device 11 along the radial direction of the bottom cover plate 12. Thus, the structural strength of the bottom cover plate 12 is improved by the reinforcing rib 121, thereby improving the structural strength of the housing 1.

[0071] A battery according to an embodiment of the second aspect of the utility model (not shown) comprises a battery cell 100 according to an embodiment of the first aspect of the utility model.

[0072] According to the battery of the present invention, by adopting the battery core 100, the service life of the battery is prolonged and the safety of the battery is improved.

[0073] A battery module (not shown) according to an embodiment of the third aspect of the utility model comprises a battery according to an embodiment of the second aspect of the utility model.

[0074] According to the battery module of the utility model, by adopting the above-mentioned battery, the service life of the battery module is prolonged and the use safety of the battery module is improved.

[0075] A battery pack (not shown) according to an embodiment of the fourth aspect of the utility model comprises a battery according to an embodiment of the second aspect of the utility model or a battery module according to an embodiment of the third aspect of the utility model.

[0076] According to the battery pack of the utility model, by adopting the above-mentioned battery or the above-mentioned battery module, the battery pack is prevented from being damaged, thereby extending the service life of the battery pack, and the pressure can be effectively released when the gas pressure inside the battery is too high, thereby improving the safety of the battery pack.

[0077] An electrical device (not shown) according to an embodiment of the fifth aspect of the utility model comprises a battery pack according to an embodiment of the fourth aspect of the utility model.

[0078] According to the power-consuming device of the utility model, the use performance of the power-consuming device is improved by adopting the above-mentioned battery pack. The power-consuming device may be a vehicle, an electric two-wheeled vehicle, an electric multi-wheeled vehicle, an energy storage cabinet, an unmanned aerial vehicle, a ship, etc.

[0079] Other structures and operations of the battery cell 100, battery, battery module, battery pack and electrical device according to the embodiment of the utility model are well known to those skilled in the art and will not be described in detail here.

[0080] In the description of the present invention, it is necessary to understand that the terms "center", "length", "thickness", "up", "down", "inside", "outside", "axial", "radial", "circumferential" and the like indicating orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0081] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example.

[0082] Although the embodiments of the present invention have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A battery cell, characterized in that: include: shell; A pole core, the pole core is arranged in the shell, the two ends of the pole core in the length direction are respectively a first end and a second end, and the first end is provided with a positive pole tab and a negative pole tab; A separator is arranged in the shell, the separator is located between the second end of the pole core and the shell, and the separator separates the pole core from the shell.

2. The battery cell according to claim 1, characterized in that: At least one through hole is formed on the separator.

3. The battery cell according to claim 2, characterized in that: The housing is provided with a pressure relief device, and the pressure relief device is configured to release the internal pressure of the battery cell.

4. The battery cell according to claim 3, characterized in that: The shell includes a shell body and a bottom cover plate connected to each other, the separator separates the pole core from the bottom cover plate, and the pressure relief device is arranged on the bottom cover plate.

5. The battery cell according to claim 4, characterized in that: At least a portion of the pressure relief device is opposite to the through hole along a thickness direction of the partition.

6. The battery cell according to claim 5, characterized in that: The area where the projection of at least a portion of the pressure relief device on the separator along the thickness direction of the separator overlaps with the through hole is S1, and the cross-sectional area of ​​the pressure relief device along a plane perpendicular to the thickness direction of the separator is S2, wherein S1 and S2 satisfy: 50%≤S1 / S2≤100%.

7. The battery cell according to claim 2, characterized in that: The cross-sectional area of ​​the through hole along a plane perpendicular to the thickness direction of the separator is S3, and the cross-sectional area of ​​the separator along a plane perpendicular to the thickness direction of the separator is S4, wherein S3 and S4 satisfy: 30%≤S3 / S4≤80%.

8. The battery cell according to claim 2, characterized in that: There are multiple through holes, and the multiple through holes constitute at least one first through hole group and at least one second through hole group. The first through hole group includes multiple first through holes, and the multiple first through holes are arranged at intervals along the radial direction of the partition. The second through hole group includes multiple second through holes, and the multiple second through holes are arranged at intervals along the circumferential direction of the partition. The multiple second through holes and the multiple first through holes are spaced apart from each other.

9. The battery cell according to claim 8, characterized in that: A cross-sectional area of ​​the second through hole along a plane perpendicular to the thickness direction of the partition is greater than a cross-sectional area of ​​the first through hole along a plane perpendicular to the thickness direction of the partition.

10. The battery cell according to claim 8, characterized in that: The cross-sectional areas of the plurality of first through holes along a plane perpendicular to the thickness direction of the separator are all the same; or At least two of the plurality of first through holes have different cross-sectional areas along a plane perpendicular to the thickness direction of the partition.

11. The battery cell according to claim 8, characterized in that: There are multiple groups of the first through hole groups, and the multiple groups of the first through hole groups are arranged at intervals along the circumference of the separator, and the second through hole is located between two adjacent groups of the first through hole groups.

12. The battery cell according to claim 8, characterized in that: The minimum distance between any of the second through holes and the first through holes of the adjacent first through hole group adjacent to the edge of the separator is l1, wherein l1 satisfies: 0.5 mm ≤ l1 ≤ 3 mm; and / or The minimum distance between two adjacent first through holes of the first through hole group adjacent to the edge of the separator is l2, wherein l2 satisfies: 0.5mm≤l2≤3mm.

13. The battery cell according to claim 1, characterized in that: The thickness of the separator is h, wherein h satisfies: 0.3 mm ≤ h ≤ 2 mm.

14. The battery cell according to any one of claims 1 to 13, characterized in that: The separator is a polyethylene terephthalate piece or a polypropylene piece.

15. A battery, characterized in that: Comprising a battery cell according to any one of claims 1 to 14.

16. A battery module, characterized in that: Comprising a battery according to claim 15.

17. A battery pack, characterized in that: Comprising the battery according to claim 15 or the battery module according to claim 16.

18. An electrical device, characterized in that: Comprising a battery pack according to claim 17.

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