Top cover assembly, battery pack and power battery

Abstract

The application discloses a top cover assembly, a battery pack and a power battery, and belongs to the technical field of batteries. The top cover assembly comprises a cover plate and a sealing element. The cover plate is provided with a liquid injection hole. The sealing element is arranged on the cover plate and is used for sealing the liquid injection hole. The sealing element is configured to elastically deform under the action of an external force to switch between a first state and a second state. When the sealing element is in the first state, the liquid injection hole is closed. When the sealing element is in the second state, the liquid injection hole is opened. In a subsequent welding process, the liquid injection hole can remain closed, and the problem of electrolyte spraying is less likely to occur. This is beneficial to making the effective liquid injection amount of the battery close to a design value, thereby prolonging the service life of the battery to a certain extent.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a top cover assembly, a battery pack, and a power battery. Background Technology

[0002] Lithium-ion batteries are widely used in electric vehicles, energy storage systems, and portable electronic devices due to their high energy density and long cycle life. As requirements for range, power, and lifespan increase, the utilization rate of cell space is approaching its limit, and the requirements for structural layout and electrolyte injection process are becoming more stringent.

[0003] In related technologies, after electrolyte injection into the battery cell, a plug or rubber pin is usually installed at the injection hole to seal it. After the electrolyte injection is completed, during subsequent welding processes, the electrolyte can easily spray out from the injection hole, resulting in the effective electrolyte injection volume of the battery cell being lower than the design value. This may lead to insufficient electrolyte during use, thereby affecting battery life. Utility Model Content

[0004] This application provides a top cover assembly, a battery pack, and a power battery, which makes it difficult for electrolyte to spray out from the injection hole, thereby at least partially solving the above-mentioned technical problems.

[0005] To achieve the above objectives, according to a first aspect of this application, a top cover assembly is provided, comprising: A cover plate, wherein an injection hole is formed on the cover plate; and A sealing element, disposed on the cover plate, is used to seal the injection hole; The sealing element is configured to undergo elastic deformation under external force to switch between a first state and a second state; when the sealing element is in the first state, the injection hole is closed, and when the sealing element is in the second state, the injection hole is open.

[0006] By adopting the above technical solution, the seal can be in a second state under the action of the injection component when electrolyte is injected, thus completing the electrolyte injection; when the injection component is withdrawn after the electrolyte injection is completed, the seal returns to the first state under its own elasticity to seal the injection hole. Therefore, during subsequent welding, the injection hole remains closed, reducing the likelihood of electrolyte ejection and helping to ensure that the effective electrolyte injection volume of the battery cell is close to the design value, thereby extending the battery's lifespan to a certain extent.

[0007] In some embodiments, the seal is provided with an opening slot, and the seal is configured to deform under external force to open the opening slot; When the seal is in the first state, the opening slit is closed to seal the injection hole; when the seal is in the second state, the opening slit is opened to open the injection hole.

[0008] By adopting the above technical solution, the seal can open and close by relying on its own elastic deformation, thereby avoiding dependence on additional mechanisms. Compared with other types of seals, this solution is easier to achieve in terms of compact structure, which helps to reduce manufacturing costs and allows for more electrolyte storage space within a limited area.

[0009] In some embodiments, the opening slit extends from the center of the seal toward the outer periphery of the seal.

[0010] By adopting the above technical solution, when the opening slit is opened, the channel formed extends radially to the outer periphery of the seal, which is conducive to establishing a communication path between the injection hole and the inside of the battery, facilitating the smooth injection of electrolyte into the battery, and to a certain extent helping to achieve the stability of the injection process.

[0011] In some embodiments, the central axis of the injection hole passes through the center of the seal.

[0012] By adopting the above technical solution, when the seal is in the second state, the channel it forms can be aligned with the center of the injection hole, which helps to maintain the connectivity between the channel and the injection hole, facilitates the smooth injection of electrolyte into the battery, and improves the stability of the injection process.

[0013] In some embodiments, multiple opening seams are provided.

[0014] By adopting the above technical solution, when the seal is in the second state due to external force, multiple opening slits open at the same time, which can expand the opening area, thereby reducing the opening resistance and facilitating the smooth injection of electrolyte into the battery, which is conducive to achieving a stable electrolyte injection process.

[0015] In some embodiments, the multiple opening slits are radially distributed with the center of the seal as the center.

[0016] By adopting the above technical solution, when the seal is in the second state due to external force, the radial opening slits can open simultaneously to form a uniform radial opening area, which helps to reduce the opening resistance and facilitates the smooth injection of electrolyte into the battery, thereby achieving a stable electrolyte injection process to a certain extent.

[0017] In some embodiments, the plurality of opening slits are distributed at equal angular intervals with respect to the center of the seal.

[0018] By adopting the above technical solution, when the seal is in the second state due to external force, the equally spaced opening slits can open simultaneously. Since each opening slit is subjected to uniform force, the opening resistance is consistent, thus forming a stable and reliable channel, which is conducive to the smooth injection of electrolyte into the battery and to a certain extent achieves uniformity and stability in the injection process.

[0019] In some embodiments, the number of openings is even.

[0020] By adopting the above technical solution, since the number of opening slits is even and they all extend outward from the center of the seal, a symmetrical slit layout can be formed. Each opening slit corresponds to another opening slit along the radial direction, which is equivalent to forming a complete channel along the diameter direction. This makes the resistance of the seal more uniform when it is opened, thereby reducing the difficulty of opening and facilitating the smooth injection of electrolyte into the battery, thus improving the stability and reliability of the electrolyte injection process.

[0021] In some embodiments, the seal is disposed outside the injection hole, and the length of the opening is greater than the radius of the injection hole.

[0022] By adopting the above technical solution, when the external injection component is inserted through the injection hole, the injection component gradually enters the seal, pushing the seal to deform inwards towards the battery along the injection direction, thereby opening the opening. At this time, the seal is not blocked by the cover plate and can smoothly open the channel to complete the injection. After the injection is completed, if the internal pressure of the battery increases, the internal pressure will push the seal to rebound in the opposite direction to the injection direction. Since the length of the opening is greater than the radius of the injection hole, the seal will be partially blocked by the cover plate during the rebound process, thereby suppressing the accidental opening of the opening, which helps to prevent electrolyte leakage and improves the safety and reliability of the injection process.

[0023] In some embodiments, the cover plate is provided with a mounting groove surrounding the injection hole, and the seal is located within the mounting groove.

[0024] By adopting the above technical solution, the seal, positioned within the mounting groove, not only achieves stable fixation, preventing displacement or tilting during electrolyte injection, but also facilitates elastic deformation of the seal along a predetermined direction. This ensures reliable opening of the opening and accurate rebound sealing of the injection hole after injection. Furthermore, the mounting groove design prevents the seal from occupying internal battery space, thus providing more injection space for the electrolyte. This facilitates achieving the required injection volume while maintaining a compact internal battery structure, improving the stability and sealing effect of the injection process.

[0025] In some embodiments, the seal and the cover are connected by heat fusion or by adhesive.

[0026] By adopting the above technical solution, the seal and the cover plate can be reliably fixed by hot melting or adhesive connection, so that the seal maintains a stable position during liquid injection and rebound, and avoids the opening gap from not being able to open or close properly due to loosening or displacement, thereby improving the sealing reliability and overall structural stability of the liquid injection process.

[0027] In some embodiments, the cover plate is provided with a baffle plate opposite to the injection hole, and a flow passage is formed between the cover plate and the baffle plate. The baffle plate is configured to abut against the injection member when the injection member is inserted into the injection hole to limit the insertion depth of the injection member.

[0028] By adopting the above technical solution, the baffle can limit the insertion depth of the injection component, prevent the injection component from entering the cell excessively, thereby reducing the risk of short circuit caused by excessively deep operation, while ensuring the safety and reliability of the liquid injection process.

[0029] According to a second aspect of this application, a battery pack is provided, including the top cover assembly described above.

[0030] By adopting the above technical solution and applying the top cover assembly to the battery pack, it is possible to ensure that the electrolyte injection hole is reliably sealed during the electrolyte injection process, effectively preventing electrolyte leakage, while achieving higher space utilization and electrolyte injection accuracy, thereby improving the overall safety, reliability and service life of the battery pack.

[0031] According to a third aspect of this application, a power battery is also provided, including the top cover assembly described in the above technical solution, or including the battery pack described in the above technical solution.

[0032] By adopting the above technical solutions and applying the top cover assembly or battery pack to the power battery, the flow and sealing of the electrolyte can be effectively controlled during the electrolyte injection process, ensuring reliable sealing of the injection hole, reducing the risk of electrolyte leakage, and optimizing the utilization of the battery's internal space and the accuracy of electrolyte injection, thereby improving the safety, cycle stability and service life of the power battery.

[0033] In the top cover assembly of this application embodiment, a sealing element is provided so that it enters a second state under the action of the injection component during electrolyte injection to complete the injection; after the injection is completed, as the injection component is withdrawn, the sealing element returns to a first state under its own elasticity to close the injection hole. This allows the injection hole to remain closed during subsequent welding processes, reducing the risk of electrolyte ejection and helping to ensure that the actual electrolyte injection volume of the cell is close to the design value, thereby extending the battery life to a certain extent.

[0034] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments 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.

[0036] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings, wherein the same reference numerals in the following description denote the same parts.

[0037] Figure 1 This is a schematic diagram of the structure of the top cover assembly provided in the exemplary embodiment of this disclosure when the seal is in the first state; Figure 2 This is a front view of the top cover assembly provided in the exemplary embodiment of this disclosure when the seal is in the second state; Figure 3 This is a partial structural schematic diagram of a cross-sectional view of the cover plate provided in an exemplary embodiment of this disclosure; Figure 4 This is a schematic diagram of the structure of the top cover assembly provided in the exemplary embodiment of this disclosure when the seal is in the second state; Figure 5 This is a side view of the top cover assembly provided in an exemplary embodiment of this disclosure; Figure 6 This is a schematic diagram of the structure of the top cover assembly provided in an exemplary embodiment of this disclosure.

[0038] Explanation of reference numerals in the attached figures: 100, Cover plate; 110, Injection hole; 120, Baffle plate; 130, Flow hole; 140, Mounting groove; 200, Seal; 210, Opening slot. Detailed Implementation

[0039] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the protection scope of this application.

[0040] According to the first aspect of this application, referring to Figures 1 to 6 This disclosure provides a top cover assembly for use in a battery pack. The top cover assembly includes a cover plate 100 and a seal 200, wherein the cover plate 100 has an injection hole 110 for injecting electrolyte into the battery pack.

[0041] In some embodiments, a seal 200 is disposed on the cover plate 100 to seal the injection hole 110. With the seal 200, even if the internal pressure of the battery pack increases during subsequent production processes such as welding after electrolyte injection into the battery pack is completed, the seal 200 can keep the injection hole 110 closed, thereby preventing electrolyte from spraying out of the injection hole 110 and ensuring the stability of the battery capacity.

[0042] In some embodiments, the seal 200 is configured to undergo elastic deformation under external force to switch between a first state and a second state; when the seal 200 is in the first state, the injection hole 110 is closed, and when the seal 200 is in the second state, the injection hole 110 is open.

[0043] Specifically, the seal 200 can be made of an elastomeric material, and its shape and size are suitable for covering the injection hole 110. When the injection component is inserted into the injection hole 110, the end of the injection component contacts and pushes the seal 200, causing the seal 200 to elastically deform along the injection direction, thereby switching to the second state and forming a channel in the injection hole 110. After the injection is completed, as the injection component is withdrawn, the seal 200 rebounds in the opposite direction under its own elasticity, returning to the first state, thereby keeping the injection hole 110 closed.

[0044] In some embodiments, the seal 200 is an integral sheet, with its bottom surface in contact with the cover plate 100 being planar or slightly convex, so that it can fit against the injection hole 110 opening in the first state, thereby facilitating the sealing of the injection hole 110. In other embodiments, the seal 200 is provided with one or more radial opening slits 210, which can be straight, arc-shaped, or serrated, so as to form a channel under the action of external force, and close under the action of the seal 200's own elasticity after the injection is completed.

[0045] In some embodiments, the seal 200 may be made of an elastomeric material, such as silicone rubber, fluororubber, or polyurethane elastomer, to provide a certain elastic modulus that allows it to deform stably during injection and rebound.

[0046] In some embodiments, the material of the seal 200 can be heat-resistant to adapt to subsequent welding or heat treatment processes, while also being resistant to chemical corrosion to prevent expansion, degradation, or leakage during prolonged contact with the electrolyte. In particular embodiments, the seal 200 may employ a composite material structure, such as embedding reinforcing fibers in an elastomer, to improve its deformation controllability and durability.

[0047] In some embodiments, refer to Figure 1 and Figure 2The seal 200 is provided with an opening slit 210, which is configured to deform under external force to open the opening slit 210. In the first state, the opening slit 210 is closed, sealing the injection hole 110; in the second state, the opening slit 210 is open, opening the injection hole 110. During the injection process, when the injection component is inserted into the injection hole 110 and acts on the seal 200, the seal 200 is pushed by the external force and deforms, causing the opening slit 210 to gradually open, thus forming a channel communicating with the injection hole 110, allowing the electrolyte to smoothly enter the battery. After the injection is completed and the injection component is removed, the seal 200 rebounds under its own elasticity, and the opening slit 210 closes, thereby sealing the injection hole 110 and reducing the risk of electrolyte leakage.

[0048] The seal 200 can open and close by its own elastic deformation without the need for additional mechanisms. Its compact structure helps reduce manufacturing costs and allows for electrolyte storage within a limited space, which is beneficial to electrolyte injection efficiency and battery performance stability.

[0049] It should be understood that the seal 200 does not deform under all external forces. When an external force is applied to the seal 200, the seal 200 will gradually undergo elastic deformation only when the force exceeds a preset range, and the opening slit 210 will gradually open as the external force continues to increase. In other words, when the external force is below the preset range, the seal 200 basically maintains its original shape, the opening slit 210 remains closed, and will not open due to slight external forces.

[0050] In some embodiments, refer to Figure 1 and Figure 2 The opening slit 210 can be single or multiple, extending from the center of the seal 200 outwards. Its shape can be selected exemplarily based on actual fluid injection requirements and the elastic properties of the seal 200 material. In some embodiments, the opening slit 210 is straight, extending radially outwards from the center of the seal 200, which facilitates uniform opening and the formation of a channel under external force. In other embodiments, the opening slit 210 can be arc-shaped, extending from the center to the outer periphery along a certain curvature, so as to form a progressively opening channel when the seal 200 is deformed by force, reducing local stress concentration.

[0051] For example, multiple opening slits 210 can form multiple independently deformable at least two diaphragm flaps, each of which can deform to form an injection channel for liquid to pass through on the seal 200.

[0052] In some embodiments, the opening slit 210 can be serrated or wavy. This shape increases the total length of the slit when it is opened, thereby expanding the area of ​​the injection channel. Simultaneously, it facilitates better contact of the slit edges when the seal 200 springs back to close, enhancing the sealing effect. The width and depth of the opening slit 210 can be selected based on the elastic modulus of the seal 200 and the expected injection pressure, ensuring both unobstructed flow during injection and full closure after injection to suppress electrolyte leakage.

[0053] In some embodiments, refer to Figure 1 and Figure 2 The opening slit 210 can extend in any direction; it can be in the form of a straight line, arc, sawtooth, wave, or irregular curve. A straight opening slit 210 can open quickly under external force to form a direct channel; an arc or curved opening slit 210 can gradually open when the seal 200 is deformed by force, reducing local stress concentration; a sawtooth or wave opening slit 210 can increase the total length of the gap, thereby expanding the area of ​​the injection channel, and at the same time, it is beneficial to edge fitting when the seal 200 rebounds and closes, enhancing the sealing effect.

[0054] The number, length, width, and depth of the opening slits 210 can be selected and optimized based on the elastic modulus of the seal 200, the injection pressure, and the size of the injection hole 110. By rationally designing the shape and arrangement of the opening slits 210, a stable channel can be formed during the injection process, allowing the electrolyte to be smoothly injected into the battery. After the injection is completed, the seal 200 closes the opening slits 210 by its own elastic rebound, which helps to suppress electrolyte overflow to a certain extent and maintain the effective sealing of the injection hole 110.

[0055] In some embodiments, refer to Figure 1 and Figure 2 The opening slit 210 extends from the center of the seal 200 to the outer periphery of the seal 200. When the opening slit 210 is opened, the channel it forms extends radially to the outer periphery of the seal 200, which helps to establish a communication path between the injection hole 110 and the inside of the battery, facilitating the smooth injection of electrolyte into the battery and contributing to the stability of the injection process to a certain extent.

[0056] In some embodiments, the central axis of the injection hole 110 passes through the center of the seal 200. When the seal 200 is in the second state under the action of the injection component, the channel formed by the opening slit 210 can be aligned with the central axis of the injection hole 110, maintaining the communication between the channel and the injection hole 110. This structure can further ensure the uniformity and smoothness of electrolyte injection, and after the injection is completed, the seal 200 relies on its own elasticity to rebound to the first state to close the injection hole 110, reducing the risk of accidental electrolyte ejection or leakage, thereby improving the reliability and stability of the injection process, and helping to keep the actual electrolyte injection volume of the battery cell close to the design value.

[0057] In some embodiments, refer to Figure 1 and Figure 2 Multiple opening slits 210 are provided. These opening slits 210 can be distributed in different directions on the seal 200, such as radially or annularly. When the seal 200 is subjected to external force, such as when the injection component is inserted into the injection hole 110 and gradually squeezes the seal 200, the seal 200 can change from a first state to a second state. At this time, multiple opening slits 210 can open simultaneously, forming multiple channels connecting the inside of the battery. Because the number of opening slits 210 increases, the deformation required for a single opening slit 210 is relatively reduced, making it easier to open under the same external force, thereby reducing the opening resistance to a certain extent.

[0058] When multiple opening slits 210 open simultaneously, the overall opening area of ​​the resulting channel increases relatively, which facilitates faster and smoother entry of the electrolyte into the battery during the injection process, thereby reducing potential liquid stagnation. This not only helps to achieve a more stable injection process but also facilitates the injection of a larger volume of electrolyte within a limited time.

[0059] In this embodiment, "multiple opening seams 210" can be understood as three, four, or more straight opening seams, or as opening seams of different shapes such as arcs or zigzags. Under different distribution methods, the multiple opening seams 210 can all expand the opening area to a certain extent when they open, achieving similar technical effects.

[0060] In some embodiments, refer to Figure 1 and Figure 2 Multiple opening slits 210 are radially distributed with the center of the seal 200 as the center. This radial distribution means that the included angles between each opening slit 210 are basically the same, ensuring that the opening slits 210 remain symmetrical with respect to the center position of the seal 200. The advantage of this arrangement is that when the injection component is inserted into the injection hole 110 and gradually presses against the seal 200, the seal 200 experiences a more uniform force, reducing the likelihood of misalignment or excessive localized stress.

[0061] When an external force causes the seal 200 to change from its first state to its second state, the radially arranged opening slits 210 simultaneously open in the radial direction, forming a relatively uniform channel on the seal 200. Because the opening slits 210 are evenly distributed, the overall opening area expands in a ring shape, thereby reducing the deformation resistance required for a single opening to a certain extent. Compared to single or asymmetrically distributed opening slits 210, this structure facilitates the uniform distribution of resistance during fluid injection, avoids local blockage, and helps achieve a stable fluid passage.

[0062] With the opening slit 210 open, the electrolyte can flow evenly into the battery through multiple radial channels, and the flow path is relatively dispersed. This not only facilitates the smooth entry of the electrolyte into the cell, but also reduces the impact risk caused by excessive local flow velocity to a certain extent, thereby improving the stability of the electrolyte injection process.

[0063] In this embodiment, the "radial distribution" is not limited to a strictly symmetrical form with perfectly equal angles; it can also be an approximately radial arrangement, where each opening slit 210 extends radially relative to the center. Such arrangements can achieve the technical effects of reducing opening resistance, increasing opening area, and facilitating smooth electrolyte injection.

[0064] In some embodiments, refer to Figure 1 and Figure 2 Multiple opening slits 210 are distributed at equal angles around the center of the seal 200. "Equal angle distribution" here can be understood as the opening slits 210 being spaced at approximately uniform angles relative to the center of the seal 200. For example, if four opening slits 210 are provided on the seal 200, the angle between two adjacent opening slits 210 will be close to 90°. This distribution makes the opening slits 210 symmetrical overall, thus providing better balance under stress.

[0065] When the injection component is inserted through the injection hole 110 and acts on the seal 200, the seal 200 changes from a first state to a second state, and the multiple opening slits 210, which are evenly spaced, can open simultaneously in the radial direction. Because the opening slits 210 are evenly positioned, their stress conditions are basically consistent, making it less likely for a particular area to open first or for some parts to experience excessive resistance. Through this structural layout, the opening resistance is relatively balanced in all directions, and the deformation process of the seal 200 is smoother, which can reduce the risk of blockage during the injection process to a certain extent.

[0066] In the open state, multiple evenly distributed opening slits 210 simultaneously form channels, which are dispersed around the injection hole 110, resulting in an overall opening with a near-annular uniform structure. This structure facilitates uniform flow of the electrolyte during injection, avoiding impact phenomena caused by excessively high flow velocity in one direction, thereby improving the smoothness and stability of electrolyte injection to a certain extent.

[0067] In this embodiment, "equiangular distribution" is not limited to completely equal angle division, but can also be approximately equal angle arrangement. As long as the opening slots 210 are evenly distributed, the above-mentioned effects of reducing opening resistance and improving fluid flow uniformity can be achieved.

[0068] In some embodiments, the number of opening slits 210 is even. For example, the number of opening slits 210 can be 2, 4, 6, or 8, etc. Since the number of opening slits 210 is even, and each opening slit 210 extends from the center of the seal 200 outwards, a symmetrical slit layout can be formed. For each opening slit 210, there is a corresponding opening slit 210 extending along the same diameter direction on the other side of the seal 200, thereby forming a pair of opening slits 210 arranged opposite to each other on the structure of the seal 200.

[0069] When the seal 200 changes from its first state to its second state under the action of external force, the paired opening slots 210 can open simultaneously. Because the opening slots 210 are symmetrically distributed around the center of the seal 200, the force distribution is relatively balanced, making it less likely for the opening resistance to be greater in one direction or for the seal to open prematurely in another. This symmetrical design ensures that the resistance of the seal 200 during the opening process is relatively consistent in different directions, thereby reducing the overall difficulty of opening to a certain extent.

[0070] When the seal 200 is in the open state, the paired opening slits 210 are interconnected in the diametrical direction, effectively forming a complete channel on the seal 200. This channel provides a relatively straight flow path for the electrolyte, facilitating smoother flow during the injection process and reducing the possibility of localized blockages. Simultaneously, the multiple sets of symmetrically distributed radial channels provide multiple stable flow paths, enabling the electrolyte to be injected more evenly into the battery, thus contributing to the stability and balance of the injection process.

[0071] In this embodiment, "even number" is not limited to a specific numerical range and can be adjusted according to the actual battery structure and the required liquid injection volume. For example, when the battery capacity is large, the opening area can be increased by setting more opening slots 210, thereby accommodating a higher liquid injection rate.

[0072] In some embodiments, the seal 200 is configured to be pressed against the cover plate 100 under the pressure inside the cell, thereby closing the opening slit 210. As the internal pressure of the cell increases, the seal 200 adheres more tightly to the cover plate 100, thus enhancing the reliability of maintaining the closed state of the opening slit 210. This structural arrangement prevents electrolyte leakage along the opening slit 210 due to internal pressure, improving the sealing performance of the top cover assembly after electrolyte injection.

[0073] In some embodiments, refer to Figure 3 and Figure 4 The sealing element 200 is disposed outside the injection hole 110, and the length of the opening slit 210 is greater than the radius of the injection hole 110. Exemplarily, the sealing element 200 is disposed on the side of the cover plate 100 facing the inside of the battery pack. During the injection operation, an external injection component (e.g., an injection needle or injection nozzle) is inserted through the injection hole 110. As the injection component gradually contacts and presses against the sealing element 200, the sealing element 200 undergoes elastic deformation under the action of external force along the injection direction, i.e., from the cover plate 100 towards the inside of the battery. As the deformation intensifies, the opening slit 210 on the sealing element 200 gradually opens, thereby forming a connecting channel, allowing the electrolyte to smoothly pass through the injection hole 110 and enter the battery. Because the sealing element 200 is disposed outside the injection hole 110, it is not directly obstructed by the cover plate 100 during this process, thus the opening slit 210 can open relatively smoothly, which is beneficial for completing the electrolyte injection.

[0074] After the electrolyte injection is completed and the injection component is removed, the seal 200 tends to return to its initial state due to its own elasticity, thereby closing the opening slit 210. In subsequent processes, such as welding or encapsulation, if the internal pressure of the battery increases due to temperature changes or gas generation, the seal 200 will be pushed by the reverse pressure from inside the battery, rebounding in the opposite direction to the electrolyte injection. During this process, because the length of the opening slit 210 is greater than the radius of the injection hole 110, a portion of the seal 200 will be blocked by the edge of the cover plate 100, thus limiting the opening of the opening slit 210. This structural arrangement can, to a certain extent, suppress the accidental opening of the opening slit 210 due to internal pressure, helping to reduce the risk of electrolyte leakage from the injection hole 110.

[0075] Through the above structural design, the seal 200 can not only smoothly form a channel for electrolyte injection during the injection process, but also enhance the stability of closure through its synergistic effect with the cover plate 100 after injection, thus balancing the smoothness of the injection operation with the reliability of the subsequent sealing state. It should be noted that "reliability" here refers to the seal 200 maintaining a good sealing effect under most operating conditions, and does not mean that the risk of leakage is completely eliminated.

[0076] In some embodiments, refer to Figure 3 and Figure 4 The cover plate 100 is provided with a mounting groove 140, which surrounds the injection hole 110, and the seal 200 is located within the mounting groove 140. Exemplarily, the mounting groove 140 is located on the side of the cover plate 100 facing the inside of the battery pack. This structural arrangement allows the seal 200 to achieve a relatively stable installation position, preventing positional shift or tilting during injection. Therefore, when the external injection component is inserted into the injection hole 110 and contacts the seal 200, the seal 200 can elastically deform in a predetermined direction under the constraint of the mounting groove 140, avoiding irregular deformation and facilitating the opening slit 210 to open under external force. After injection, as the injection component is withdrawn, the seal 200 rebounds elastically and returns to its initial position under the guidance of the mounting groove 140, closing the opening slit 210 and acting as a channel blocker.

[0077] Furthermore, since the seal 200 is embedded within the mounting groove 140, its thickness does not extend excessively into the battery's internal space. This allows for more usable space within the battery, facilitating electrolyte injection and contributing to achieving the required injection volume. Simultaneously, the compact internal layout of the battery is maintained, preventing the seal 200 from occupying extra space and thus minimizing interference with the assembly of other components.

[0078] Through the above design, the mounting groove 140 and the seal 200 form a mutually cooperating relationship: on the one hand, the mounting groove 140 plays a positioning and guiding role for the seal 200, which is conducive to improving the stability of the opening and closing process; on the other hand, the presence of the mounting groove 140 can prevent the seal 200 from directly protruding into the internal space of the battery, thereby taking into account the requirements of electrolyte injection and the compactness of the internal structure of the battery, which to a certain extent helps to improve the stability and sealing effect of the electrolyte injection process.

[0079] In some embodiments, the seal 200 and the cover plate 100 are connected by heat fusion or by adhesive. By heat fusion, the material of the seal 200 can be fused with the material of the cover plate 100 after localized heating, forming an integral structure upon cooling, thereby ensuring a tight bond between the seal 200 and the cover plate 100. Alternatively, by applying and curing an adhesive to the contact area between the seal 200 and the cover plate 100, a stable adhesive layer can be formed between them.

[0080] With the above connection method, the seal 200 is fixed in a preset position and is not easily displaced or loosened during the injection process due to the squeezing of the external injection component or changes in internal pressure. Thus, when the injection component is inserted into the injection hole 110 and acts on the seal 200, the seal 200 can undergo elastic deformation within a predetermined area, thereby causing the opening slit 210 to open smoothly; after the injection is completed, the seal 200 returns to its initial position under the constraint of the connection part due to its own elastic rebound, causing the opening slit 210 to close again.

[0081] Therefore, fixing the seal 200 to the cover plate 100 by hot melting or adhesive means can, on the one hand, facilitate a more stable assembly structure, which helps to ensure that the deformation direction of the seal 200 is clear during the opening and closing process and reduces the possibility of abnormal deformation; on the other hand, the fixed connection can reduce the risk of sealing failure caused by the displacement of the seal 200 to a certain extent, thereby helping to improve the stability and sealing effect of the liquid injection process.

[0082] In some embodiments, refer to Figure 5 and Figure 6 The cover plate 100 is provided with a baffle plate 120 facing the injection hole 110. A flow hole 130 is formed between the cover plate 100 and the baffle plate 120. The baffle plate 120 is configured to abut against the injection component when the injection component is inserted into the injection hole 110 to limit the insertion depth of the injection component.

[0083] Specifically, the baffle 120 can be a sheet or ring structure and is fixed to the cover plate 100, with its position aligned with the central axis of the injection hole 110. When the injection component is inserted along the injection hole 110, the surface of the baffle 120 contacts the end of the injection component, preventing the injection component from penetrating further into the battery. Since a flow hole 130 is formed between the baffle 120 and the cover plate 100, the electrolyte can flow into the battery through the flow hole 130. Therefore, even if the baffle 120 restricts the injection component, it will not affect the injection path of the electrolyte.

[0084] Through the aforementioned structure, the baffle 120 serves a limiting function to a certain extent, controlling the insertion depth of the injection component within a reasonable range. This helps prevent the injection component from directly contacting the cell electrodes or other internal components, thereby reducing the risk of short circuits or localized damage that may be caused by excessively deep insertion. Furthermore, the presence of the baffle 120 also makes the electrolyte injection path clearer. During the injection process, the electrolyte, in cooperation with the injection component and the flow orifice 130, can be smoothly introduced into the battery, contributing to improved stability of the injection process.

[0085] In some embodiments, the seal 200 is an elastic seal. An elastic seal can undergo reversible deformation when subjected to external force and recover its original shape after the force is removed. Utilizing this characteristic, when an external injection component is inserted into the injection hole 110, the seal 200 can be pushed to open the opening slit 210, thereby forming a channel for smooth electrolyte injection into the battery cell; after injection, as the injection component is withdrawn, the seal 200 rebounds under its own elasticity, causing the opening slit 210 to close again, thus sealing the injection hole 110. This method of opening and closing through elastic deformation simplifies the structural design to some extent, helps maintain overall compactness, and allows for more electrolyte storage space within a limited area, while also contributing to stable injection and sealing effects.

[0086] According to a second aspect of this disclosure, a battery pack is provided, including the top cover assembly of the above embodiments. This battery pack possesses all the beneficial effects of the aforementioned top cover assembly, which will not be elaborated further herein.

[0087] According to a third aspect of this disclosure, a power battery is provided, including the top cover assembly of the above embodiments, or including the battery pack of the above embodiments. This power battery has all the beneficial effects of the above-described top cover assembly or battery pack, which will not be elaborated further herein.

[0088] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0089] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0090] The embodiments, implementation methods, and related technical features of this application can be combined and substituted for each other without conflict.

[0091] The above are merely preferred embodiments of this application and are not intended to limit this application in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the scope of the technical solution of this application.

Claims

1. A top cover assembly, characterized in that, include: A cover plate (100), on which an injection hole (110) is formed; and A sealing element (200) is disposed on the cover plate (100) for sealing the injection hole (110); The sealing element (200) is configured to undergo elastic deformation under external force to switch between a first state and a second state; when the sealing element (200) is in the first state, the injection hole (110) is closed, and when the sealing element (200) is in the second state, the injection hole (110) is open.

2. The top cover assembly according to claim 1, characterized in that, The seal (200) is provided with an opening slot (210), and the seal (200) is configured to deform under the action of an external force so that the opening slot (210) opens; When the seal (200) is in the first state, the opening slit (210) is closed so that the injection hole (110) is sealed; when the seal (200) is in the second state, the opening slit (210) is opened so that the injection hole (110) is opened.

3. The top cover assembly according to claim 2, characterized in that, The opening slot (210) extends from the center of the seal (200) toward the outer periphery of the seal (200).

4. The top cover assembly according to claim 3, characterized in that, The central axis of the injection hole (110) passes through the center of the seal (200).

5. The top cover assembly according to claim 3, characterized in that, The opening seam (210) is provided with multiple seams.

6. The top cover assembly according to claim 5, characterized in that, The multiple opening slits (210) are radially distributed with the center of the seal (200) as the center.

7. The top cover assembly according to claim 5, characterized in that, The multiple opening slots (210) are distributed at equal angles with the center of the seal (200) as the center.

8. The top cover assembly according to claim 5, characterized in that, The number of opening seams (210) is even.

9. The top cover assembly according to claim 3, characterized in that, The sealing element (200) is disposed outside the injection hole (110), and the length of the opening slit (210) is greater than the radius of the injection hole (110).

10. The top cover assembly according to claim 9, characterized in that, The cover plate (100) is provided with a mounting groove (140), which surrounds the injection hole (110), and the sealing element (200) is located in the mounting groove (140).

11. The top cover assembly according to any one of claims 1 to 10, characterized in that, The seal (200) and the cover plate (100) are connected by heat fusion or by adhesive.

12. The top cover assembly according to any one of claims 1 to 10, characterized in that, The cover plate (100) is provided with a baffle plate (120) facing the injection hole (110), and a flow hole (130) is formed between the cover plate (100) and the baffle plate (120). The baffle plate (120) is configured to abut against the injection component when the injection component is inserted into the injection hole (110) to limit the insertion depth of the injection component.

13. A battery pack, characterized in that, Includes the top cover assembly as described in any one of claims 1 to 12.

14. A power battery, characterized in that, It includes the top cover assembly as described in any one of claims 1 to 12, or the battery pack as described in claim 13.

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