Battery cell

Abstract

The utility model discloses a single battery and relates to the technical field of batteries, the single battery comprises a shell, a first cover plate assembly, a second cover plate assembly, a first inner core, a second inner core and a separation structure, a liquid injection hole is formed in the side wall of the shell, the separation structure is arranged in the shell, and a first containing space is defined by the separation structure, the shell and the first cover plate assembly; the separation structure, the shell and the second cover plate assembly define a second containing space, the first inner core and the second inner core are arranged in the first containing space and the second containing space respectively, the separation structure is provided with a liquid passing channel, and the liquid injection hole communicates with the first containing space and the second containing space through the liquid passing channel; according to the technical scheme provided by the embodiment of the invention, the liquid injection hole is formed in the side wall of the shell, so that the electrolyte can uniformly permeate into the two inner cores, the consistency of the battery is improved, the output performance of the battery is optimized, and moreover, the diffusion path of the electrolyte is shorter and the liquid injection speed can be increased by forming the liquid injection hole in the middle of the shell.

Description

battery cell Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery cell. Background Technology

[0002] Square batteries are a common type of lithium-ion battery packaging. Their casings typically employ a square structure, offering high space utilization and good mechanical stability. This compact battery structure, with its neatly arranged internal components, effectively utilizes the space within the battery pack, thereby increasing energy density. The cores of square batteries are generally classified into wound and stacked types based on their manufacturing process.

[0003] Taking a stacked battery as an example, its core is composed of multiple layers of positive electrode plates, negative electrode plates, and separators stacked alternately to form a compact electrode assembly, which is then encapsulated in a square casing. To increase the battery capacity, the core of the battery cell is designed to be longer. However, due to its structural characteristics, when electrolyte is injected from one end of the cell, it is difficult for the electrolyte to evenly cover the end of the core furthest from the injection hole, affecting the battery's output performance. Summary of the Invention

[0004] Several embodiments in this application propose a battery cell designed to further simplify the electrolyte injection process and optimize the electrolyte injection effect.

[0005] One embodiment of this application proposes a battery cell comprising:

[0006] The housing has a liquid injection hole on its side wall;

[0007] A first cover plate assembly is disposed at the first opening of the housing;

[0008] A second cover plate assembly is disposed at the second opening of the housing;

[0009] A partition structure is disposed within the housing; the partition structure, the housing, and the first cover plate assembly enclose a first accommodating space, and the partition structure, the housing, and the second cover plate assembly enclose a second accommodating space.

[0010] A first inner core is disposed within the first receiving space; and

[0011] The second inner core is disposed within the second accommodating space;

[0012] The partition structure has a liquid passage, and the injection hole is connected to the first accommodating space and the second accommodating space through the liquid passage.

[0013] In one embodiment, the partition structure includes a first partition and a second partition spaced apart, the first partition and the second partition forming the liquid passage, and respectively provided with a first liquid outlet and a second liquid outlet, the first liquid outlet connecting the first accommodating space and the liquid passage, and the second liquid outlet connecting the second accommodating space and the liquid passage.

[0014] In one embodiment, the partition structure further includes a plurality of ribs, each of which is connected at both ends to the first partition and the second partition and is located within the liquid passage, and the plurality of ribs are spaced apart along the length of the partition;

[0015] Each of the ribs is provided with a liquid passage hole; the rib near the liquid injection hole is provided with a liquid inlet hole that communicates with the liquid injection hole.

[0016] In one embodiment, the two partitions are respectively provided with a plurality of first liquid outlet holes and a plurality of second liquid outlet holes; the plurality of first liquid outlet holes are arranged sequentially at intervals along the length direction of the first partition; and / or

[0017] Multiple second liquid outlet holes are arranged sequentially at intervals along the length of the second partition.

[0018] In one embodiment, the distance between the two partitions is 3mm to 6mm.

[0019] In one embodiment, the length of the housing is greater than or equal to 400 mm; the width of the housing is greater than or equal to 10 mm; and the height of the housing is greater than or equal to 90 mm.

[0020] In one embodiment, the capacity of the battery cell is greater than or equal to 280 Ah.

[0021] In one embodiment, the first inner core has a first abutting surface facing the second inner core, and the second inner core has a second abutting surface facing the first inner core, the first abutting surface and the second abutting surface respectively abutting against opposite sides of the partition structure.

[0022] In one embodiment, the injection hole includes a first hole segment and a second hole segment that are connected to each other, wherein the inner diameter of the first hole segment is larger than the inner diameter of the second hole segment;

[0023] The battery cell also includes a sealing pin, at least a portion of which is located in the second hole section and seals against the inner wall of the second hole section.

[0024] In one embodiment, a pressure relief valve is provided on the side of the housing facing away from the injection hole, and the pressure relief valve is connected to the first accommodating space and the second accommodating space respectively.

[0025] In several embodiments provided in this application, the electrolyte injection hole is located on the side wall of the housing, ensuring that its distance from the first inner core and the second inner core is equal, thereby guaranteeing uniform electrolyte injection. Specifically, a partition structure is located inside the housing and encloses the housing and the first cover plate assembly to form a first receiving space, and encloses the housing and the second cover plate assembly to form a second receiving space. The first inner core and the second inner core are respectively located in the first receiving space and the second receiving space. The partition structure has a liquid passage, which is opposite to the electrolyte injection hole located on the side wall of the housing. The electrolyte injection hole is connected to the first inner core and the second inner core through the liquid passage. When electrolyte is injected through the electrolyte injection hole, it is guided through the liquid passage and then enters the first receiving space and the second receiving space respectively. Since the electrolyte injection hole is located in the middle of the housing, the electrolyte can uniformly penetrate the two inner cores, thereby improving battery consistency and optimizing its output performance. Moreover, by setting the electrolyte injection hole in the middle of the housing, the diffusion path of the electrolyte is shorter, which can also increase the injection speed. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments or prior art of this application, the drawings used in the description of the embodiments or prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0027] Figure 1 is a structural schematic diagram of a battery cell according to an embodiment of the present application;

[0028] Figure 2 is a structural schematic diagram of the battery cell in Figure 1 from another angle;

[0029] Figure 3 is an exploded schematic diagram of the battery cell provided in this application;

[0030] Figure 4 is a schematic diagram of the separator structure in a single battery cell;

[0031] Figure 5 is a cross-sectional view of the partition structure in Figure 4;

[0032] Figure 6 is a cross-sectional view of an embodiment of a battery cell provided in this application;

[0033] Figure 7 is a magnified view of part A in Figure 6.

[0034] Explanation of icon numbers:

[0035] 100. Battery cell; 1. Housing; 11. First cover assembly; 111. First positive terminal; 112. First negative terminal; 1a. Injection hole; 1a1. First hole segment; 1a2. Second hole segment; 1b. First receiving space; 1c. Second receiving space; 1d. First opening; 1e. Second opening; 12. Second cover assembly; 121. Second positive terminal; 122. Second negative terminal; 13. Pressure relief valve; 14. Sealing nail; 141. Nail head; 142. Rod; 2. First inner core; 21. First positive electrode tab; 22. First negative electrode tab; 3. Second inner core; 31. Second positive electrode tab; 32. Second negative electrode tab; 4. Separating structure; 41. First partition; 411. First liquid outlet; 42. Second partition; 421. Second liquid outlet; 43. Rib; 431. Liquid passage hole; 4a. Liquid passage channel; 4b. Liquid inlet hole. Detailed Implementation

[0036] The technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings of several embodiments. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0037] It should be noted that if directional indications (such as up, down, left, right, front, back, etc.) are involved in multiple embodiments of this application, the directional indications are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0038] Furthermore, if multiple embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text implies three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0039] Taking a stacked battery as an example, its core is composed of multiple layers of positive electrode plates, negative electrode plates, and separators stacked alternately to form a compact electrode assembly, which is then encapsulated in a square casing. To increase the battery capacity, the core of the battery cell is designed to be longer. However, due to its structural characteristics, when electrolyte is injected from one end of the cell, it is difficult for the electrolyte to evenly cover the end of the core furthest from the injection hole 1a, thus affecting the battery's output performance.

[0040] To address the aforementioned problems, this application proposes a battery cell 100 to solve the technical issues raised above.

[0041] Please refer to Figures 1 to 7. In one embodiment of this application, the battery cell 100 includes a housing 1, a first cover plate assembly 11, a second cover plate assembly 12, a first inner core 2, a second inner core 3, and a partition structure 4. The side wall of the housing 1 is provided with a liquid injection hole 1a. The first cover plate assembly 11 is disposed at the first opening 1d of the housing 1, and the second cover plate assembly 12 is disposed at the second opening 1e of the housing 1. The partition structure 4 is disposed inside the housing 1 and surrounds the housing 1 and the first cover plate assembly 11 to form a first receiving space 1b, and surrounds the housing 1 and the second cover plate assembly 12 to form a second receiving space 1c. The first inner core 2 and the second inner core 3 are respectively disposed in the first receiving space 1b and the second receiving space 1c. The partition structure 4 has a liquid passage 4a, and the liquid injection hole 1a is connected to the first receiving space 1b and the second receiving space 1c through the liquid passage 4a.

[0042] Understandably, the increased length of the battery cell 100 is to improve its energy storage capacity and meet usage requirements. Compared to a traditional single-core battery cell 100, the battery cell 100 in this application has two cores, namely a first core 2 and a second core 3. The first core 2 and the second core 3 are arranged along the length of the battery cell 100, thereby shortening the length of a single core. Specifically, please refer to Figure 3. To prevent short circuits caused by contact between one end of the first core 2 and the second core 3, the first core 2 and the second core 3 are separated by a separator structure 4. By dividing the long cell's core into two independent cores, the path of current through the electrodes is shortened, significantly reducing the battery's internal resistance, thereby reducing heat generation and improving energy efficiency. Moreover, the bipolar design allows the current to be distributed more evenly throughout the cell, reducing current concentration and thus improving charging and discharging efficiency.

[0043] In one embodiment of this application, the length of the casing 1 is greater than or equal to 400 mm, the width of the casing 1 is greater than or equal to 10 mm, and the height of the casing 1 is greater than or equal to 90 mm, forming a relatively flat cuboid structure. In this embodiment, the capacity of the battery cell 100 is greater than or equal to 280 Ah. Compared to traditional battery cells of the same size, the battery cell 100 proposed in this solution can significantly reduce the internal resistance of the battery, thereby reducing the heat generation of the battery and improving energy efficiency. Moreover, the bipolar design allows the current to be distributed more evenly throughout the cell, reducing current concentration and thus improving charge and discharge efficiency.

[0044] In the technical solution of this application, the housing 1 has four sidewalls and two end faces, which are arranged opposite to each other, that is, the two ends of the first positive electrode post 111, the first negative electrode post 112, and the second positive electrode post 121 and the second negative electrode post 122 are respectively installed. The four sidewalls are connected end to end to form a ring structure with a rectangular cross-section. It should be noted that the liquid injection hole 1a on the housing 1 can be opened on any sidewall except for the two end faces. It can be located on the large sidewall or the small sidewall. This application does not limit this. In one embodiment of this application, the liquid injection hole 1a is located on one of the small sidewalls. Specifically, please refer to Figure 1. Since the area of ​​the small sidewall is relatively small, the electrolyte encounters less resistance during injection and can penetrate more quickly along the length of the cell, thereby shortening the time required for the electrolyte to fill the entire cell. In addition, opening the liquid injection hole 1a on the small sidewall has less impact on the product appearance. For the installation and placement of the battery cell 100, it is usually installed in a side-mounted manner, that is, one of the small side walls is placed on the mounting surface, while the other small side wall is set upwards. The electrolyte injection hole 1a is opened on this small side wall, which makes it easier to perform electrolyte injection. In addition, if the battery cell 100 needs to be replenished with electrolyte during subsequent use, it can also be added from the top surface, which is convenient for operation.

[0045] For longer battery cells, during the electrolyte injection process, the electrolyte is injected into one end. The electrolyte needs time to permeate and ensure it fills all areas of the core. This waiting period significantly increases the injection time, reducing overall battery production efficiency and impacting yield. In large-scale production, this can lead to production delays and increased costs. Therefore, in several embodiments provided in this application, the electrolyte injection hole 1a is located on the sidewall of the housing 1, ensuring that its distance from the first core 2 and the second core 3 is equal, thereby guaranteeing uniform electrolyte injection. Specifically, the first inner core 2 and the second inner core 3 are both disposed within the housing 1 and are connected to the first positive electrode post 111, the first negative electrode post 112, the second positive electrode post 121, and the second negative electrode post 122 located at both ends of the housing 1, respectively. A partition structure 4 is provided between the first inner core 2 and the second inner core 3. The partition structure 4 has a liquid passage 4a, which is opposite to the liquid injection hole 1a located on the side wall of the housing 1. The liquid injection hole 1a can communicate with the first inner core 2 and the second inner core 3 through the liquid passage 4a. When electrolyte is injected through the liquid injection hole 1a, it will be guided through the liquid passage 4a and then enter the first inner core 2 and the second inner core 3, respectively. Since the liquid injection hole 1a is located in the middle of the housing 1, the electrolyte can permeate the two inner cores evenly, thereby improving the consistency of the battery and optimizing its output performance. Moreover, by placing the liquid injection hole 1a in the middle of the housing 1, the diffusion path of the electrolyte is shorter, which can also increase the injection speed.

[0046] To ensure the reliability of the isolation and the lightweight structure, the partition structure 4 includes two spaced-apart partitions, namely the first partition 41 and the second partition 42, which are connected by multiple ribs 43. Specifically, referring to the second negative electrode tab 32 in Figure 4, a hollow area is formed between the first partition 41 and the second partition 42. The hollow area not only isolates the first inner core 2 and the second inner core 3, but also reduces the material of the partition structure 4, thereby achieving lightweighting. In addition, the hollow area between the two partitions can also serve as a guide for the electrolyte. Specifically, the partition structure 4 is located between the first inner core 2 and the second inner core 3, and the injection hole 1a is also located in the middle of the shell 1. The injection hole 1a and the partition structure 4 are opposite to each other and connected. The electrolyte injected through the injection hole 1a will first enter the liquid passage 4a between the two partitions through the liquid inlet 4b at the top of the partition structure 4, and then flow into the two inner cores respectively.

[0047] In one embodiment of this application, to facilitate the electrolyte in the liquid passage 4a to wet the electrodes and diaphragms of the two inner cores, a first liquid outlet hole 411 is provided near the first inner core 2, i.e., the first diaphragm 41, and a second liquid outlet hole 421 is provided near the second inner core 3, i.e., the second diaphragm 42. Specifically, please refer to Figure 4 for the second negative electrode tab 32. The first liquid outlet hole 411 is used to guide the electrolyte in the liquid passage 4a to the electrodes and diaphragms of the first inner core 2, thereby wetting them; the second liquid outlet hole 421 is used to guide the electrolyte in the liquid passage 4a to the electrodes and diaphragms of the second inner core 3, thereby wetting them. It should be noted that the first liquid outlet 411 is disposed on the first separator 41, and the second liquid outlet 421 is disposed on the second separator 42. They can be disposed opposite to each other or staggered; this application does not impose any limitation on this. In one embodiment of this application, the first liquid outlet 411 and the second liquid outlet 421 are staggered in the width direction of the separator. This effectively avoids direct convection of the electrolyte between the two inner cores, thereby reducing mutual interference between the electrolytes. The staggered arrangement of the outlets allows the electrolyte to be more evenly distributed into the electrodes and separators of each inner core, ensuring that the electrolyte can fully wet all areas of each inner core and improving the uniformity of electrolyte distribution. Simultaneously, the staggered design can optimize the electrolyte flow path, reduce the resistance of the electrolyte during flow, further improve the electrolyte injection efficiency, and ensure the performance stability and consistency of the battery during charging and discharging.

[0048] In another embodiment of this application, a plurality of first liquid outlet holes 411 are provided near the separator 41 (the first separator 41) of the first inner core 2, and a plurality of second liquid outlet holes 421 are provided near the separator 42 (the second separator 42). Specifically, referring further to the second negative electrode tab 32 in Figure 4, in this embodiment, the plurality of first liquid outlet holes 411 are evenly spaced along the length of the separator, and the plurality of second liquid outlet holes 421 are also evenly spaced along the length of the separator. By providing a plurality of liquid outlet holes, the uniformity of electrolyte distribution within the cell can be significantly improved. The plurality of liquid outlet holes ensures that the electrolyte flows evenly into various areas of the cell from multiple points, reducing the flow resistance and penetration time of the electrolyte within the cell, thereby wetting the electrode and separator more quickly and evenly. This design helps to improve the charge and discharge efficiency of the battery, reduce internal resistance, reduce local overheating, and improve the overall performance and lifespan of the battery. In addition, by increasing the number of liquid outlet holes, the overall weight of the battery cell 100 can be further reduced, thereby achieving battery lightweighting.

[0049] In the technical solution of the present application, two partition plates are connected by the rib plate 43 in the middle. Each rib plate 43 is provided with a liquid passing hole 431. Specifically, please further refer to FIG. 5. The liquid passing hole 431 can ensure that the electrolyte passes through, so as to ensure that the electrode plates and diaphragms of the inner core at the end far from the liquid injection hole 1a can also be wetted by the electrolyte. Further, the first liquid outlet hole 411 and the second liquid outlet hole 421 are both located between two adjacent rib plates 43. When the electrolyte enters the liquid passing channel 4a from the liquid injection hole 1a, due to the relatively large injection pressure of the electrolyte and the limited throughput of the liquid passing holes 431 on the rib plate 43, the space formed by the rib plate 43 and the two partition plates can play a role in buffering the electrolyte. The electrolyte accumulated in this space finally discharges from the first liquid outlet hole 411 and the second liquid outlet hole 421 on the two partition plates and then enters the two inner cores. In this way, the design of multiple rib plates 43 can control the flow rate of the electrolyte, avoiding the high-pressure electrolyte directly reaching the bottom of the housing 1, which may cause the upper part of the electrode plates and diaphragms not to be fully wetted. The rib plates 43 correspond to the liquid outlet holes one by one, so as to ensure the uniformity of the inner core wetted by the electrolyte along the length direction of the partition plate. According to the actual product requirements, the liquid passing holes 431 can also be added based on this embodiment. That is, each rib plate 43 is provided with two or more liquid passing holes 431, so that when the electrolyte flows in the liquid passing channel 4a, the flow rate of the electrolyte can be further increased, thereby improving the production efficiency of the battery.

[0050] In the above embodiment, the rib plate 43 can be arranged at the central position of the two partition plates or can connect the two ends of the partition plates to form a rectangular frame structure. The present application does not limit this. In an embodiment of the present application, the partition structure 4 is in an overall eye-shaped structure. The two ends of the two partition plates, that is, the first partition plate 41 and the second partition plate 42, are respectively connected by the rib plate 43. The setting of the rib plate 43 can significantly enhance the structural strength and stability of the partition structure 4, ensuring that the partition structure 4 will not deform or displace during the charge and discharge process of the battery and when subjected to external impacts, thereby guaranteeing the effective isolation between the first inner core 2 and the second inner core 3 and preventing the occurrence of short-circuit phenomena. Secondly, the rib plate 43 arranged between the two partition plates can optimize the flow path of the electrolyte. The rib plate 43 not only plays a supporting role but also can guide the electrolyte to be more evenly distributed into the two inner cores, further improving the wetting effect of the electrolyte. In addition, the hollow structure of the partition structure 4 can effectively utilize the internal space of the battery, improve the overall energy density of the battery, simplify the battery assembly process, reduce the production cost, and enhance the reliability and safety of the battery.

[0051] In the above embodiments, the surface area of ​​the partition is adapted to the cross-sectional dimensions of the first inner core 2 and the second inner core 3. Specifically, please refer to Figure 3. By designing the surface area of ​​the two partitions to be the same as the cross-sectional area of ​​the first inner core 2 and the second inner core 3, it can be ensured that when the first inner core 2 and the second inner core 3 are in contact with the two partitions respectively, the partitions can completely cover the structure of the inner core, thereby ensuring that no structure of the first inner core 2 and the second inner core 3 will come into contact and cause a short circuit.

[0052] In the technical solution of this application, the two separators in the separator structure 4 and the rib 43 disposed between the two separators are integrally formed. Specifically, the separator structure 4 is manufactured using insulating material to ensure electrical isolation between the first inner core 2 and the second inner core 3. In one embodiment of this application, the separator structure 4 is preferably made of polycarbonate (PC) material and is manufactured by injection molding. PC material has excellent electrical insulation properties, which can ensure that short circuits do not occur between the inner cores. At the same time, its high strength and high temperature resistance can effectively support the inner core structure and prevent deformation caused by mechanical stress or thermal expansion. In addition, PC material has good chemical stability and is not easily corroded by electrolyte, thereby extending the service life of the separator and further enhancing the overall performance and reliability of the battery.

[0053] It should be noted that the electrolyte passage 4a is formed by two spaced-apart partitions and the inner wall of the housing 1. The distance between the two partitions is the width of the electrolyte passage 4a. The width of the electrolyte passage 4a is typically between 3mm and 6mm, and the specific width is adjusted according to the actual needs of the product. For example, when the capacity of the battery cell 100 is large, the internal space of the housing 1 is larger, and more electrolyte needs to be filled. In this case, the width of the electrolyte passage 4a can be increased to 6mm. At this time, the cross-section of the electrolyte passage 4a is larger, and the electrolyte flow rate per unit time is greater, thereby increasing the electrolyte filling speed and improving production efficiency. On the other hand, when the capacity of the battery cell 100 is small, the internal space of the housing 1 is small, and the volume of electrolyte filled is correspondingly smaller. A larger electrolyte passage 4a is not needed, and the width of the electrolyte passage 4a can be appropriately reduced, such as to 3mm. This can further compress the volume of the partition structure 4, which helps to achieve battery miniaturization. In addition, ensuring that the width of the liquid passage 4a is greater than 3mm can ensure that the separation structure 4 provides sufficient support strength for the housing 1 and the inner core, further optimizing the structure of the battery cell 100.

[0054] Furthermore, the separator structure 4 can also be designed and manufactured integrally with the housing 1. That is, the separator structure 4 divides the space inside the housing 1 into a first accommodating space 1b and a second accommodating space 1c that are separated from each other. Specifically, please refer to Figure 6. The first inner core 2 and the second inner core 3 are respectively accommodated in the first accommodating space 1b and the second accommodating space 1c. The side of the first inner core 2 facing away from its electrode tab is also the first abutting surface, and the side of the second inner core 3 facing away from its electrode tab is also the second abutting surface. The first abutting surface and the second abutting surface abut against the two partitions in the separator structure 4, respectively. In this embodiment, the first inner core 2 and the second inner core 3 are designed to be of equal length and abut against the partitions, which can ensure that the spatial layout of the two inner cores inside the battery is symmetrical and compact, avoiding the waste of internal space and structural imbalance caused by the difference in length. At the same time, the abutting design allows the separator structure 4 to tightly separate the two inner cores, enhancing the reliability of the isolation and effectively preventing the risk of short circuit between the inner cores. The separator structure 4 also provides a certain supporting effect for the first inner core 2 and the second inner core 3.

[0055] To improve the electrolyte filling rate, the injection hole 1a includes a first segment 1a1 and a second segment 1a2 that are connected. Specifically, referring to Figure 7, the first segment 1a1 is the segment away from the inlet hole 4b, and the second segment 1a2 is the segment close to the inlet hole 4b. By designing the inner diameter of the first segment 1a1 to be larger than that of the second segment 1a2, the electrolyte flow rate can be accelerated, thereby making the electrolyte filling process more time-saving. It is understood that the first segment 1a1 can also be designed as a tapered structure to accelerate the injection of electrolyte. This application does not limit the specific structure of the injection hole 1a.

[0056] To achieve sealing of the interior of the battery cell 100 and prevent electrolyte leakage from the casing 1, the battery cell 100 also includes a sealing pin 14. Specifically, referring to Figure 3, the sealing pin 14 is inserted into the injection hole 1a and abuts against the inner wall of the second hole section 1a2 of the injection hole 1a. After the electrolyte injection is completed, the sealing pin 14 is inserted into the injection hole 1a, so that at least part of its structure is located in the second hole section 1a2 of the injection hole 1a and abuts against the hole wall of the second hole section 1a2. The sealing pin 14 is similar in shape to a screw and has a pin head. The sealing nail 141 and rod 142 are designed with an outer diameter that matches the inner diameter of the second hole segment 1a2 to ensure a tight seal. The nail head 141 is larger than the inner diameter of the second hole segment 1a2 and matches the inner diameter of the first hole segment 1a1, thus covering the opening of the second hole segment 1a2. The lower surface of the nail head 141 overlaps the outer surface of the housing 1. The nail head 141 is welded to the housing 1 using laser welding to achieve a seal. Laser welding is achieved by precisely controlling the energy and pulse of the laser beam to melt part of the structural material to form a whole. First, the sealing nail 14 is inserted into the injection hole 1a and initially fixed using spot welding. Then, continuous laser welding is used along the first part of the preset welding trajectory, and pulsed laser welding is used along the second part of the preset welding trajectory. This welding method, which combines continuous light and pulsed light, ensures both welding efficiency and welding quality, effectively avoids welding defects such as porosity and cracks, and ensures the sealing performance and structural strength of the weld.

[0057] The above description is merely an exemplary embodiment of this application and does not limit the patent scope of this application. Any equivalent structural transformations made based on the technical concept of this application and the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this application.

Claims

1. A battery cell, characterized in that, include: A housing (1) has a liquid injection hole (1a) on its side wall; a first cover plate assembly (11) is disposed at the first opening (1d) of the housing (1); a second cover plate assembly (12) is disposed at the second opening (1e) of the housing (1); a partition structure (4) is disposed inside the housing (1); the partition structure (4), the housing (1), and the first cover plate assembly (11) enclose a first accommodating space (1b), and the partition structure (4), the housing (1), and the second cover plate assembly (12) enclose a second accommodating space (1c); a first inner core (2) is disposed inside the first accommodating space (1b); and a second inner core (3) is disposed inside the second accommodating space (1c); wherein the partition structure (4) has a liquid passage (4a), and the liquid injection hole (1a) is connected to the first accommodating space (1b) and the second accommodating space (1c) through the liquid passage (4a).

2. The battery cell as described in claim 1, characterized in that, The partition structure (4) includes a first partition (41) and a second partition (42) spaced apart. The first partition (41) and the second partition (42) enclose the liquid passage (4a) and are respectively provided with a first liquid outlet (411) and a second liquid outlet (421). The first liquid outlet (411) connects the first accommodating space (1b) and the liquid passage (4a), and the second liquid outlet (421) connects the second accommodating space (1c) and the liquid passage (4a).

3. The battery cell as described in claim 2, characterized in that, The partition structure (4) further includes a plurality of ribs (43), each of which is connected to the first partition (41) and the second partition (42) at both ends and is located in the liquid passage (4a). The plurality of ribs (43) are spaced apart along the length of the partition. Each of the ribs (43) is provided with a liquid passage hole (431). The rib (43) near the liquid injection hole (1a) is provided with a liquid inlet hole (4b) communicating with the liquid injection hole (1a).

4. The battery cell as described in claim 2, characterized in that, The two partitions are respectively provided with a plurality of first liquid outlet holes (411) and a plurality of second liquid outlet holes (421); the plurality of first liquid outlet holes (411) are arranged at intervals along the length direction of the first partition (41); and / or the plurality of second liquid outlet holes (421) are arranged at intervals along the length direction of the second partition (42).

5. The battery cell as described in claim 2, characterized in that, The distance between the two partitions is 3mm to 6mm.

6. The battery cell according to any one of claims 1 to 5, characterized in that, The length of the shell (1) is greater than or equal to 400 mm; the width of the shell (1) is greater than or equal to 10 mm; and the height of the shell (1) is greater than or equal to 90 mm.

7. The battery cell according to any one of claims 1 to 5, characterized in that, The capacity of the battery cell is greater than or equal to 280Ah.

8. The battery cell according to any one of claims 1 to 5, characterized in that, The first inner core (2) has a first abutting surface facing the second inner core (3), and the second inner core (3) has a second abutting surface facing the first inner core (2). The first abutting surface and the second abutting surface abut against the opposite two sides of the partition structure (4), respectively.

9. The battery cell according to any one of claims 1 to 5, characterized in that, The injection hole (1a) includes a first hole segment (1a1) and a second hole segment (1a2) that are connected to each other. The inner diameter of the first hole segment (1a1) is larger than the inner diameter of the second hole segment (1a2). The battery cell also includes a sealing pin (14). At least a portion of the structure of the sealing pin (14) is disposed in the second hole segment (1a2) and seals against the inner wall of the second hole segment (1a2).

10. The battery cell according to any one of claims 1 to 5, characterized in that, The housing (1) is provided with a pressure relief valve (13) on the side opposite to the injection hole (1a), and the pressure relief valve (13) is connected to the first accommodating space (1b) and the second accommodating space (1c) respectively.

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