Battery cell

Abstract

The utility model provides a battery cell. The battery cell comprises an electrode assembly; the top cover assembly is arranged above the electrode assembly and is connected with the electrode assembly; an insulating film covering the side surface and the bottom surface of the electrode assembly to insulate the electrode assembly; the insulating film comprises a bottom insulating layer and a side insulating layer which are connected with each other, one side, close to the electrode assembly, of the side insulating layer is provided with a capsule chamber for accommodating an electrolyte, and one side, close to the electrode assembly, of the capsule chamber is provided with a liquid injection hole, so that the electrolyte in the capsule chamber flows into the battery cell through the liquid injection hole; according to the battery, the bag chambers and the liquid injection holes are formed in the side insulating layers, so that the high-concentration electrolyte can be stored in advance, the bag chambers are extruded by the electrode assembly, the high-concentration electrolyte can be supplemented into the battery cell through the liquid injection holes, the electrolyte and an additive are supplemented into the battery cell, and it is ensured that the battery cell keeps good working efficiency; the overall performance of the battery cell is maintained, the service life of the battery cell is prolonged, and the product quality is improved.

Description

Technical Field

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

[0002] With the continuous advancement of energy storage technology, power lithium batteries are gradually moving towards higher energy density and super-fast charging. The key to achieving high energy density and super-fast charging lies in strictly limiting the electrolyte injection coefficient of individual cells and controlling the additive content of the electrolyte within a suitable range. However, in practical applications, due to the lack of effective monitoring methods, users find it difficult to accurately assess the consumption of electrolyte and additives in the cells. Insufficient assessment accuracy can lead to users being unable to replenish electrolyte and additives in the cells in a timely manner, thereby affecting the cell's working efficiency and overall performance. Over time, this can not only shorten the cell's lifespan but may also lead to a decline in cell performance or even damage. Utility Model Content

[0003] In view of the above, this application aims to provide a battery cell that solves some or all of the aforementioned technical problems.

[0004] For the purposes described above, this application provides a battery cell, comprising:

[0005] Electrode assembly;

[0006] A top cover assembly is disposed above the electrode assembly and connected to the electrode assembly;

[0007] An insulating film is provided to cover the sides and bottom of the electrode assembly to insulate the electrode assembly. The insulating film includes a bottom insulating layer and a side insulating layer that are connected to each other. The side insulating layer has a chamber for containing electrolyte on the side near the electrode assembly. The chamber has an injection hole on the side near the electrode assembly so that the electrolyte in the chamber flows into the cell through the injection hole.

[0008] As can be seen from the above, the battery cell provided in this application has a chamber with an injection hole on the side of the side insulation layer near the electrode assembly, which can pre-store a high concentration of electrolyte. When the battery cell is in a circulating state and the electrode assembly expands, the chamber can be filled with high concentration of electrolyte through the injection hole under the squeezing action of the electrode assembly. This timely replenishment of electrolyte and additives helps maintain the balance of electrolyte in the battery cell, ensures good working efficiency, guarantees the overall performance of the battery cell, extends the service life of the battery cell, and improves its product quality. Attached Figure Description

[0009] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the 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 these drawings without creative effort.

[0010] Figure 1 This is a schematic diagram of the battery cell structure in this application;

[0011] Figure 2 This is a schematic diagram of the insulating film and the chamber structure in this application;

[0012] Figure 3 This is a schematic diagram of the fluid replenishment component in this application;

[0013] Figure 4 This is a schematic diagram showing the connection relationship between the first connector and the second connector in this application;

[0014] Figure 5 This is a schematic diagram of the relationship between cycle time and electrolyte retention in the battery cell in this application and related technologies.

[0015] Explanation of reference numerals in the attached figures:

[0016] 100. Electrode assembly;

[0017] 200. Top cover assembly; 201. Limiting hole; 202. Limiting groove;

[0018] 300, Insulating film; 301, Chamber; 302, Injection port; 303, Release port; 310, Bottom insulating layer; 320, Side insulating layer; 321, First insulating part; 322, Second insulating part;

[0019] 400. Fluid replenishment assembly; 410. Catheter; 420. First connector; 430. Second connector; 440. Limiting component; 450. Sealing ring;

[0020] 501. Engaging part; 502. Protrusion; 503. Recess. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0022] It should be noted that, unless otherwise defined, the technical or scientific terms used in the embodiments of this application should have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," and similar terms used in this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word covers the element or object listed following the word and its equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are only used to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0023] In the pursuit of high energy density and super-fast charging performance of power lithium batteries, the electrolyte filling coefficient of a single cell (i.e., the ratio of the amount of electrolyte filling inside the cell to the cell volume) is usually strictly limited. The main reason is that within a limited space, controlling the proportion of non-active components such as electrolyte can free up more space for active materials, thereby helping to improve the energy density of the battery. In addition, a reasonable electrolyte content also helps to ensure a good electrochemical environment inside the cell and maintain the rapid charging and discharging process of the electrode components.

[0024] To ensure that the battery cell has good charge and discharge performance, the content of additives in the electrolyte needs to be controlled within an appropriate range. Additives can include film-forming additives, antioxidants, conductive additives, and solvent modifiers. Their main function is to improve the stability of the electrode interface, suppress side reactions, and improve conductivity, which is crucial for maintaining the stable operation of the battery over a long period of time. However, for the battery cell, the content of additives in the electrolyte needs to be maintained within a stable range.

[0025] Specifically, when the additive content in the electrolyte is too low, the battery cell will experience a sudden drop in capacity after long-term cycling, a phenomenon known as "cycle-induced capacity drop." The main reason for this is that an appropriate amount of additive can effectively reduce the wear and tear of electrode materials and the decomposition of electrolyte, providing necessary protection. However, when the additive content is insufficient, the protective effect is weakened, and the SEI film (solid electrolyte interface film) on the surface of the electrode assembly may become unstable and easily break, leading to a rapid decline in battery performance.

[0026] When the additive content in the electrolyte is too high, it will negatively affect the fast charging performance of the battery. The main reason is that too many additives may change the physicochemical properties of the electrolyte, such as increasing viscosity and hindering the migration of lithium ions, thereby reducing the battery's charging acceptance and rate performance. In addition, excessively high concentrations of additives may also form a thick passivation layer on the electrode surface, further affecting the diffusion rate of lithium ions.

[0027] Furthermore, even with a low electrolyte injection coefficient, excessively high additive concentrations in the electrolyte can significantly increase the internal resistance of the cell. Due to the limited volume of the cell, high-concentration additives increase the viscosity of the electrolyte, slowing down ion movement and resulting in uneven electrolyte distribution. This leads to an undesirable electric field distribution, ultimately increasing cell impedance and affecting the overall battery performance, thus impacting charge / discharge efficiency and cycle life. Therefore, to achieve high energy density and super-fast charging characteristics in power lithium batteries, it is necessary to precisely control the electrolyte injection coefficient and the content of electrolyte additives during cell design to balance battery safety, stability, and performance.

[0028] However, in practical applications, due to the lack of effective monitoring methods, users find it difficult to accurately assess the consumption of electrolyte and additives inside the battery cell. This problem caused by insufficient assessment accuracy makes it impossible for users to know the consumption of electrolyte and additives, making it difficult to replenish electrolyte and additives in the battery cell in a timely manner, thus affecting the working efficiency and overall performance of the battery cell. Over time, this will not only shorten the service life of the battery cell, but may also lead to a decline in battery cell performance or even damage.

[0029] Therefore, proper management of the state of the electrolyte and its additives inside the battery cell is crucial for maintaining the long-term stable operation of the battery cell.

[0030] In view of this, this application provides a battery cell, including an electrode assembly 100, a top cover assembly 200, and an insulating film 300; wherein, the top cover assembly 200 is disposed above the electrode assembly 100 and connected to the electrode assembly 100; the insulating film 300 covers the side and bottom surfaces of the electrode assembly 100 to insulate the electrode assembly 100; the insulating film 300 includes a bottom insulating layer 310 and a side insulating layer 320 connected to each other, and the side insulating layer 320 is provided with a chamber 301 for containing electrolyte on the side near the electrode assembly 100, and an injection hole 302 is opened on the side of the chamber 301 near the electrode assembly 100 so that the electrolyte in the chamber 301 flows into the battery cell through the injection hole 302.

[0031] Specifically, see Figure 1 and Figure 2 ,in, Figure 1 This is a schematic diagram of the battery cell structure in this application. Figure 2This is a schematic diagram of the structure of the insulating film 300 and the chamber 301 in this application.

[0032] This application provides a battery cell that automatically replenishes electrolyte and additives, such as... Figure 1 and Figure 2 As shown, the battery cell may include an electrode assembly 100 and a top cover assembly 200. The electrode assembly 100 is the core part of the internal electrochemical reaction of the battery cell, mainly composed of a positive electrode, a negative electrode, and a separator. The positive and negative electrodes are responsible for the insertion and extraction of charge carriers such as lithium ions, respectively. The separator is used to separate the positive and negative electrodes and allow charge carriers to pass through, ensuring efficient charging and discharging and safe operation of the battery cell. The top cover assembly 200 is disposed above the electrode assembly 100 and connected to the electrode assembly 100. It is used to seal and protect the battery cell to prevent electrolyte leakage. The top cover assembly 200 also includes a safety valve and a terminal post. The application of the safety valve can ensure that the battery cell can safely release pressure under abnormal conditions. The terminal post can be electrically connected to the positive and negative electrode tabs of the electrode assembly 100 to establish an electrical connection with external devices.

[0033] The battery cell also includes an insulating film 300, which covers the sides and bottom of the electrode assembly 100 to insulate the electrode assembly 100. The insulating film 300 can be a Mylar (polyester insulating film) film with good insulation performance, mechanical strength and thermal stability. Since the insulating film 300 covers both the bottom and circumferential sides of the electrode assembly 100, it can both shield and protect the electrode assembly 100 to ensure its integrity and provide electrical insulation, thus providing a good operating environment for the electrode assembly 100.

[0034] Specifically, the insulating film 300 includes a bottom insulating layer 310 and a side insulating layer 320 connected to each other. The bottom insulating layer 310 covers the bottom surface of the electrode assembly 100, and the side insulating layer 320 covers the sides of the electrode assembly 100. A chamber 301 is provided on the side of the side insulating layer 320 near the electrode assembly 100. The chamber 301 is used to contain a high-concentration electrolyte. For a high-concentration electrolyte, the concentration of additives and electrolytes is relatively high. An injection hole 302 is opened on the side of the chamber 301 near the electrode assembly 100, which serves as an outlet channel for the high-concentration electrolyte, so that the chamber 301 is connected to the inside of the battery cell. When the electrolyte in the battery cell is consumed in large quantities, an injection hole 302 is added. As the additive content decreases, the electrode assembly 100 expands and compresses the surface of the chamber 301. Due to the concentration gradient between the high-concentration electrolyte in the chamber 301 and the electrolyte in the cell, the high-concentration electrolyte stored in the chamber 301 can flow out through the injection hole 302 after being compressed by the expanding electrode assembly 100. This can replenish the electrolyte and additives inside the cell and maintain the concentration of additives inside the cell, achieving the purpose of slow release of electrolyte. This provides a good operating environment for the electrode assembly 100, prevents excessive electrolyte consumption from affecting the performance of the cell, ensures the working efficiency and overall performance of the cell, extends the service life of the cell, and reduces the risk of cell damage or safety accidents.

[0035] It should be noted that, in order to control the flow rate of high-concentration electrolyte in the capsule 301 into the cell, the injection hole 302 can be selected and designed according to the actual requirements such as the size of the cell and the capacity of the electrolyte. For example, for one capsule 301, the number of injection holes 302 can be set to 1-3, and the size of each injection hole 302 can be set to 10-100 micrometers, which will not be elaborated here.

[0036] Please see Figure 5 , Figure 5This is a structural schematic diagram illustrating the relationship between cycle time and electrolyte retention in the battery cell of this application and related technologies. Specifically, for a battery cell without chamber 301, when the electrolyte concentration in the cell decreases from 100% to 90%, the content of electrolyte and additives in the cell gradually decreases, and the performance of the battery cell assembly gradually weakens. Therefore, the cycle time of the battery cell can be maintained at approximately 1000 hours. However, for a battery cell with chamber 301, when the electrolyte concentration in the cell decreases from 100% to 90%, because there is a high concentration of electrolyte in chamber 301, and electrolyte and additives can be replenished through injection hole 302 after the electrode assembly 100 expands, the content of electrolyte and additives is relatively sufficient, and the performance of the battery cell assembly is relatively stable. Therefore, the cycle time of the battery cell can be maintained at approximately 1400 hours. Thus, it can be seen that compared with the battery cells in related technologies, the electrolyte concentration in the battery cell provided in this application decreases more slowly, resulting in a relatively longer cycle life.

[0037] In some embodiments, the side insulating layer 320 includes a first insulating film 300 and a second insulating film 300; the first insulating part 321 is connected to the bottom insulating layer 310; the second insulating part 322 is connected to the first insulating part 321; both the first insulating part 321 and the second insulating part 322 are provided with a chamber 301, the chamber 301 of the second insulating part 322 is connected to the chamber 301 of the first insulating part 321, and the injection hole 302 is opened on the side of the chamber 301 of the second insulating part 322.

[0038] Regarding the side insulating layer 320, the side insulating layer 320 is interconnected with the bottom insulating layer 310 and can cover the side of the electrode assembly 100, for covering and protecting the side of the electrode assembly 100; such as Figure 2As shown, the side insulating layer 320 includes a first insulating film 300 and a second insulating film 300; wherein, the first insulating part 321 is connected to the bottom insulating layer 310, and the second insulating part 322 is connected to the first insulating part 321, so that the electrode assembly 100 is covered on two adjacent sides through the first insulating part 321 and the second insulating part 322; both the first insulating part 321 and the second insulating part 322 are provided with a chamber 301, which can be used to pre-store high-concentration electrolyte to facilitate the replenishment of electrolyte and additives; wherein, the chamber 301 of the second insulating part 322 is connected to the chamber 301 of the first insulating part 321, and the injection hole 30 2. A cavity 301 of the second insulating part 322 is provided on the side, that is, the electrolyte can flow from the cavity 301 of the first insulating part 321 to the cavity 301 of the second insulating part 322 to replenish the cavity 301 of the second insulating part 322 with high-concentration electrolyte. The cavity 301 of the second insulating part 322 is provided with an injection hole 302. Under the expansion of the electrode assembly 100, the cavity 301 of the second insulating part 322 can replenish the cell with high-concentration electrolyte through the injection hole 302 so that the electrolyte can be released slowly to adjust the balance of the electrolyte in the cell, maintain the performance of the electrode assembly 100, and help ensure the overall performance of the cell.

[0039] In some embodiments, there are two first insulating portions 321 and two insulating portions 322, with the two first insulating portions 321 respectively covering the opposite sides of the electrode assembly 100; each first insulating portion 321 is correspondingly connected to a second insulating portion 322, and the two second insulating portions 322 respectively cover the opposite sides of the electrode assembly 100.

[0040] Taking a prismatic battery cell as an example, this cell has four opposing sides, arranged in pairs opposite each other; for example... Figure 1 and Figure 2 As shown, regarding the side insulating layer 320, when the side insulating layer 320 is in a folded state, the side insulating layer 320 can fully cover the side of the electrode assembly 100. There can be two of each of the first insulating part 321 and the second insulating part 322. The two first insulating parts 321 cover the opposite sides of the electrode assembly 100 respectively, which can shield and protect the corresponding sides. Each second insulating part 322 is connected to the first insulating part 321, so as to shield and protect the other two oppositely arranged side insulating layers 320, so as to prevent the electrode assembly 100 from being scratched or worn during the assembly process, and also to achieve a good insulation effect.

[0041] In some embodiments, the battery cell further includes a liquid replenishment assembly 400 disposed between the electrode assembly 100 and the top cover assembly 200. The liquid replenishment assembly 400 includes a conduit 410, a first connector 420, and a second connector 430. Two conduits 410 are provided, and the two conduits 410 are respectively connected to the first connector 420 and the second connector 430. Each conduit 410 is respectively connected to a chamber 301 of a first insulating part 321. One end of the first connector 420 is sealed, and the other end is connected to the second connector 430. The top cover assembly 200 has a limiting hole 201, and the second connector 430 is embedded in the limiting hole 201 and is adapted to the limiting hole 201.

[0042] Specifically, please refer to Figure 3 , Figure 3 This is a schematic diagram of the structure of the fluid replenishment component 400 in this application.

[0043] Regarding battery cells, such as Figures 1-3 As shown, the battery cell also includes a replenishment assembly 400 for supplying high-concentration electrolyte to the chamber 301. This replenishment assembly 400 is located between the electrode assembly 100 and the top cover assembly 200, and can be shielded and protected by the top cover assembly 200. Specifically, the replenishment assembly 400 includes a conduit 410, a first connector 420, and a second connector 430. Two conduits 410 are provided, each connected to the first connector 420 and the second connector 430 respectively. Each conduit 410 is also connected to a chamber 301 of a first insulating part 321, so that the high-concentration electrolyte replenished by the replenishment assembly 400 flows into the chamber 301 through the two conduits 410. The first connector 420 is sealed at one end and connected to the second connector 430 at the other end, allowing the high-concentration electrolyte replenished to the electrolyte replenishment assembly 400 to flow into the conduit 410 sequentially through the second connector 430 and the first connector 420. The top cover assembly 200 also has a limiting hole 201. By embedding the second connector 430 in the limiting hole 201 and adapting the second connector 430 to the limiting hole 201, the second connector 430 can extend to the outside of the battery cell, so that the second connector 430 can be part of the inlet end of the electrolyte replenishment assembly 400, making it convenient for the user to deliver the replenished high-concentration electrolyte into the chamber 301.

[0044] In some embodiments, the fluid replenishment assembly 400 further includes a limiting component 440, which is connected to the end of the second connector 430 away from the first connector 420; the top cover assembly 200 is provided with a limiting groove 202 communicating with the limiting hole 201, and the limiting component 440 is embedded in the limiting groove 202 and adapted to the limiting groove 202.

[0045] Regarding the electrolyte replenishment component 400, to facilitate timely replenishment of high-concentration electrolyte into the capsule chamber 301 by the user, the electrolyte replenishment component 400 needs to be connected to the top cover component 200, and the inlet end of the electrolyte replenishment component 400 should be located on the surface of the top cover component 200 and exposed relative to the battery cell; for example Figure 1 and Figure 3 As shown, the replenishment component 400 also includes a limiting component 440 for limiting its position. The limiting component 440 is connected to the end of the second connector 430 away from the first connector 420 and is in communication with the external environment. Since the limiting component 440 is embedded in the limiting groove 202 connected to the limiting hole 201 opened in the top cover component 200, and the limiting component 440 is adapted to the limiting groove 202, when the limiting groove 202 is exposed to the side away from the electrode component 100, the replenishment component 400 can be fixed to the top cover component 200 through the limiting component 440, so that the top cover component 200 provides an installation position for the replenishment component 400, ensuring that the inlet end of the replenishment component 400 can be exposed, so that high-concentration electrolyte can be replenished to the capsule 301 through the replenishment component 400.

[0046] It should be noted that, since the inlet end of the electrolyte replenishment component 400 is exposed relative to the battery cell, a plug can be embedded at the inlet end of the electrolyte replenishment component 400, i.e., at the corresponding opening of the limiting component 440, to seal the inlet end of the electrolyte replenishment component 400, thereby preventing high-concentration electrolyte from leaking from the inlet end of the electrolyte replenishment component 400 during battery cell use, which helps to ensure the overall quality of the battery cell.

[0047] In some embodiments, the diameter of the limiting groove 202 is larger than the diameter of the limiting hole 201.

[0048] like Figure 2 and Figure 3 As shown, since the limiting component 440 is connected to the end of the second connector 430 away from the electrode assembly 100, when the limiting component 440 is embedded in the limiting groove 202, the replenishing component 400 and the top cover assembly 200 can be connected, making it convenient for the user to replenish high-concentration electrolyte into the capsule 301 through the inlet end located on the surface of the top cover assembly 200; by setting the diameter of the limiting groove 202 to be larger than the diameter of the limiting hole 201, the second connector 430 can be prevented from coming out of the limiting hole 201, thereby improving the firmness and reliability of the replenishing component 400 in the top cover assembly 200.

[0049] In some embodiments, the fluid replenishment assembly 400 further includes a sealing ring 450, which is disposed between the second connector 430 and the limiting member 440, with the opposite ends of the sealing ring 450 respectively embedded in the limiting member 440 and the second connector 430.

[0050] Regarding the fluid replenishment component 400, such as Figure 3 As shown, since the limiting component 440 and the second connector 430 are interconnected, by setting the sealing ring 450 in the replenishing component 400 between the second connector 430 and the limiting component 440, and embedding its opposite ends in the limiting component 440 and the second connector 430 respectively, the sealing effect between the limiting component 440 and the second connector 430 can be improved, preventing leakage when replenishing high-concentration electrolyte and avoiding safety accidents caused by electrolyte leakage.

[0051] In some embodiments, the end of the second connector 430 away from the first connector 420 is provided with a locking portion 501, and the second connector 430 is locked to the limiting member 440 through the locking portion 501.

[0052] like Figure 3 As shown, regarding the replenishment assembly 400, the replenishment assembly 400 establishes a connection with the top cover assembly 200 through the limiting component 440, ensuring the firmness and stability of the replenishment assembly 400 installation; as Figure 3 As shown, by providing a locking part 501 at the end of the second connector 430 away from the first connector 420, when the second connector 430 and the limiting member 440 are in a connected state, since the limiting member 440 is located in the limiting groove 202, after the second connector 430 passes through the limiting hole 201, the second connector 430 can be locked onto the limiting member 440 by the locking part 501. This allows the liquid replenishment assembly 400 to limit and fix the second connector 430 away from the electrode assembly 100 in the top cover assembly 200, reducing the installation difficulty of the liquid replenishment assembly 400 and improving its installation stability and reliability.

[0053] It should be noted that, in order to improve the firmness of the connection between the second connector 430 and the limiting member 440, the limiting member 440 may be provided with a mating part that matches the engaging part 501, such as a mating groove or a mating protrusion, so that the engaging part 501 can be fully engaged with the limiting member 440, thereby improving the firmness and reliability of the connection between the second connector 430 and the limiting member 440.

[0054] In some embodiments, the first connector 420 has a protruding protrusion 502 at one end away from the electrode assembly 100, and the second connector 430 has a recessed recess 503 on the side near the electrode assembly 100, with the protrusion 502 embedded in the recessed recess 503 and adapted to the recessed recess 503.

[0055] Specifically, see Figure 4 , Figure 4 This is a schematic diagram showing the connection relationship between the first connector 420 and the second connector 430 in this application.

[0056] Regarding the electrolyte replenishment assembly 400, since the first connector 420 and the second connector 430 are interconnected, the high-concentration electrolyte flows sequentially into the second connector 430 and the first connector 420, and then flows into the corresponding chamber 301 through the conduit 410 connected to each; wherein, for example... Figure 3 and Figure 4 As shown, by providing a protruding portion 502 at the end of the first connector 420 away from the electrode assembly 100, and a recessed portion 503 on the side of the second connector 430 near the electrode assembly 100, and by embedding the protruding portion 502 into the recessed portion 503 and adapting it to the recessed portion 503, it is convenient to position and assemble the first connector 420 and the second connector 430 during the battery cell assembly, reducing the assembly difficulty between the two and improving the assembly accuracy between them.

[0057] In some embodiments, the chamber 301 of the second insulating portion 322 is further provided with a release port 303, which is located on the same side of the chamber 301 as the injection hole 302. The release port 303 has at least one of the following features:

[0058] Along the height direction of the electrode assembly 100, the height of the release port 303 is greater than the height of the injection hole 302;

[0059] The diameter of the release port 303 is larger than the diameter of the injection hole 302.

[0060] Regarding the capsule 301, during the cycling process, the electrode assembly 100 inside the cell expands and compresses the capsule 301. Due to this compression, the high-concentration electrolyte within the capsule 301 can be replenished through the injection port 302 into the cell, along with additives, to maintain the electrolyte balance. However, because the injection port 302 is relatively small, the replenishment of the high-concentration electrolyte using it is relatively slow, resulting in low sustained-release efficiency. Figure 2 As shown, by opening a release port 303 in the chamber 301 of the second insulation part 322 and placing the release port 303 and the injection hole 302 on the same side of the chamber 301, a portion of the high-concentration electrolyte can be released through the release port 303 to increase the discharge rate of the high-concentration electrolyte, thereby improving the replenishment efficiency of the electrolyte in the battery cell.

[0061] For example, regarding the release port 303, along the height direction of the electrode assembly 100, the height of the release port 303 can be set to be greater than the height of the injection hole 302. When the electrolyte consumption in the cell is small, the expansion of the electrode assembly 100 is small, and the compression of the capsule 301 is relatively low, so the high-concentration electrolyte will not be released from the release port 303. When the electrolyte consumption in the cell is large, and it is difficult to replenish the high concentration in time through the injection hole 302, the expansion of the electrode assembly 100 is relatively large, and the compression of the capsule 301 is large. At this time, the high-concentration electrolyte can be released through the release port 303 under the compression of the electrode assembly 100, thereby improving the replenishment efficiency of the high-concentration electrolyte. In addition, since the height of the release port 303 is higher than the height of the injection hole 302, when a large amount of high-concentration electrolyte is replenished in the capsule 301, it can also be directly released into the cell through the release port 303, ensuring that there is sufficient electrolyte in the cell and enabling the electrolyte to be effectively released.

[0062] For example, regarding the release port 303, since the release port 303 is used to improve the replenishment efficiency of high-concentration electrolyte, by setting the diameter of the release port 303 to be larger than the diameter of the injection hole 302, the output flow rate of high-concentration electrolyte in the capsule 301 can be increased, which is beneficial to further improve the replenishment efficiency of high-concentration electrolyte.

[0063] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of this application (including the claims) is limited to these examples; within the framework of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of the different aspects of this application as described above, which are not provided in the details for the sake of brevity.

[0064] The embodiments of this application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A battery cell, characterized in that, include: Electrode assembly; A top cover assembly is disposed above the electrode assembly and connected to the electrode assembly; An insulating film is provided to cover the sides and bottom of the electrode assembly to insulate the electrode assembly. The insulating film includes a bottom insulating layer and a side insulating layer that are connected to each other. The side insulating layer has a chamber for containing electrolyte on the side near the electrode assembly. The chamber has an injection hole on the side near the electrode assembly so that the electrolyte in the chamber flows into the cell through the injection hole.

2. The battery cell according to claim 1, characterized in that, The side insulating layer includes: The first insulating part is connected to the bottom insulating layer; The second insulating part is connected to the first insulating part; both the first insulating part and the second insulating part are provided with the chamber, the chamber of the second insulating part is connected to the chamber of the first insulating part, and the injection hole is opened on the side of the chamber of the second insulating part.

3. The battery cell according to claim 2, characterized in that, There are two of each of the first insulating portion and the second insulating portion, with the two first insulating portions respectively covering the opposite sides of the electrode assembly; each first insulating portion is connected to a corresponding second insulating portion, and the two second insulating portions respectively cover the opposite sides of the electrode assembly.

4. The battery cell according to claim 3, characterized in that, Also includes: A fluid replenishment assembly is disposed between the electrode assembly and the top cover assembly. The fluid replenishment assembly includes a conduit, a first connector, and a second connector. Two conduits are provided, and the two conduits are respectively connected to the first connector and the second connector, and each conduit is respectively connected to a chamber of the first insulating part. One end of the first connector is sealed, and the other end is connected to the second connector. The top cover assembly has a limiting hole, and the second connector is embedded in the limiting hole and adapted to the limiting hole.

5. The battery cell according to claim 4, characterized in that, The fluid replenishment component also includes: A limiting component is connected to the end of the second connector away from the first connector; the top cover assembly is provided with a limiting groove communicating with the limiting hole, and the limiting component is embedded in the limiting groove and adapted to the limiting groove.

6. The battery cell according to claim 5, characterized in that, The diameter of the limiting groove is larger than the diameter of the limiting hole.

7. The battery cell according to claim 5, characterized in that, The fluid replenishment component also includes: A sealing ring is disposed between the second connector and the limiting component, with its opposite ends embedded in the limiting component and the second connector, respectively.

8. The battery cell according to claim 5, characterized in that, The second connector has a locking part at the end away from the first connector, and the second connector is engaged with the limiting component through the locking part.

9. The battery cell according to claim 5, characterized in that, The first connector has a protruding part at one end away from the electrode assembly, and the second connector has a recessed part at one side near the electrode assembly. The protruding part is embedded in the recessed part and is adapted to the recessed part.

10. The battery cell according to any one of claims 2-9, characterized in that, The second insulating part also has a release port in its chamber, which is located on the same side of the chamber as the injection hole. The release port has at least one of the following characteristics: Along the height direction of the electrode assembly, the height of the release port is greater than the height of the injection hole; The diameter of the release port is larger than the diameter of the injection hole.

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