Cover plate assembly and battery cell

Abstract

The application discloses a cover plate assembly and a battery monomer, and relates to the technical field of batteries, wherein the cover plate assembly comprises a cover plate and a lower plastic, the cover plate is provided with a first hole, the lower plastic is arranged in a stack with the cover plate, one end of the lower plastic close to the cover plate in a first direction is provided with a convex part, the convex part is provided with a channel, the convex part penetrates through the first hole, and the channel is used for leading out a tab; in the technical scheme provided by the embodiment of the application, the one end of the lower plastic close to the cover plate in the first direction is provided with the convex part, and the channel is formed in the convex part. When the battery is assembled, the tab of the inner core end is extended towards the channel, without occupying the limited space in the shell, so that the internal space utilization rate of the battery monomer is improved.

Description

Technical Field

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

[0002] A single battery cell is the smallest independent unit of electrical energy storage that makes up a battery pack. It has complete charge and discharge functions and is the core foundation of a battery system. A single battery cell typically consists of a casing, a core, and terminals. The core is the key component for storing and releasing electrical energy and is installed inside the casing. The larger the space inside the casing, the larger the core can be installed.

[0003] Currently, the internal space utilization rate of battery cells is low, which prevents the energy density of battery cells from being further improved. Utility Model Content

[0004] This application proposes a cover plate assembly and a battery cell, which aim to optimize the space utilization inside the housing and improve the energy density of the battery cell per unit volume.

[0005] One embodiment of this application provides a cover plate assembly, comprising: Cover plate, having a first hole; The lower plastic is stacked with the cover plate. The lower plastic has a protrusion at one end near the cover plate along a first direction. The protrusion has a channel and is disposed through the first hole. The channel is used for leading out the electrode tab.

[0006] In one embodiment, the thickness of the protrusion along the first direction is greater than or equal to the thickness of the cover plate along the first direction.

[0007] In one embodiment, the cover plate assembly further includes an adapter piece, the adapter piece including a bent portion and an extension portion, the bent portion including a first bent segment and a second bent segment connected to each other, the first bent segment being connected to the extension portion, and the second bent segment being connected to the electrode tab; at least a portion of the structure of the second bent segment is disposed within the channel.

[0008] In one embodiment, the cover plate assembly further includes a protective cap disposed on the cover plate; the protective cap and the cover plate enclose a receiving cavity, the channel is connected to the receiving cavity, and the receiving cavity is used to receive the electrode tab.

[0009] In one embodiment, the protective cap has an insulating layer at one end near the protrusion along the first direction.

[0010] In one embodiment, the inner diameter of the protective cap is less than or equal to the outer diameter of the protrusion, and the protective cap is engaged with the protrusion.

[0011] In one embodiment, the channel is filled with sealant to prevent communication between the channel and the outside world.

[0012] In one embodiment, the cover plate assembly further includes a positive electrode post and a negative electrode post, the positive electrode post penetrating through the cover plate and the lower plastic part, and the negative electrode post penetrating through the cover plate and the lower plastic part.

[0013] In one embodiment, the cover plate is provided with two first holes, one of which is located near the positive terminal post, and the other of which is located near the negative terminal post; The lower plastic part has two protrusions, one of which passes through the first hole.

[0014] In one embodiment, the cover plate has an explosion-proof opening located between the two first holes, and the cover plate assembly further includes an explosion-proof valve disposed at the explosion-proof opening; The lower plastic has a flow hole, and the projection of the explosion-proof port on the lower plastic coincides with the flow hole.

[0015] One embodiment of this application also proposes a battery cell, comprising: The shell has a first opening; The cover assembly described above is disposed at the first opening; An inner core is disposed within the housing. One end of the inner core is provided with a positive electrode tab and a negative electrode tab. The positive electrode tab is disposed in one of the channels, and the negative electrode tab is disposed in the other channel.

[0016] In this application, a protrusion is provided at one end of the lower plastic near the cover plate along a first direction, and a channel is formed within the protrusion. This allows the tabs to extend into the channel, thereby preventing the tabs from retracting within the housing and occupying the limited space inside the housing, thus improving the energy density of the battery cell per unit volume. Specifically, the cover plate assembly includes a cover plate, a lower plastic, and a protrusion. The cover plate has a first hole, and the lower plastic is stacked with the cover plate. The lower plastic has a protrusion at one end near the cover plate along the first direction, and the protrusion has a channel that passes through the first hole, allowing the tabs to be led out. After the battery is assembled, the tabs at the inner core end are accommodated within the channel without occupying the limited space inside the housing, improving the internal space utilization of the battery cell. Moreover, the protrusion provides physical isolation between the tabs and the cover plate, preventing short circuits caused by contact between the tabs and the cover plate. Attached Figure Description

[0017] 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.

[0018] Figure 1 This is an exploded structural diagram of an embodiment of the cover plate assembly provided in this application; Figure 2 This is a schematic diagram of the assembly structure of an embodiment of the cover plate assembly provided in this application; Figure 3 This is a schematic diagram of the structure of the adapter piece in the cover plate assembly; Figure 4 A partial cross-sectional view of an embodiment of the battery cell provided in this application; Figure 5 A partial cross-sectional view of another embodiment of the battery cell provided in this application; Figure 6 This is a schematic diagram showing the dimensions of the height of the protrusion and the thickness of the cover plate; Figure 7 A schematic diagram of the structure of a single battery cell provided in this application; Figure 8 This is an exploded structural diagram of an embodiment of the battery cell provided in this application.

[0019] Explanation of icon numbers: 100. Cover plate assembly; 1. Cover plate; 1a. First hole; 2. Lower plastic; 2a. Flow hole; 3. Protrusion; 3a. Channel; 3b. Upper end face; 4. Protective cap; 41. Insulating layer; 4a. Receiving cavity; 4b. Inner end face; 5. Adapter piece; 51. Bending part; 511. First bending section; 512. Second bending section; 52. Extension part; 6. Positive terminal; 7. Negative terminal; 8. Explosion-proof valve; 9. Sealant; 1000, battery cell; 200, casing; 300, inner core; 310, positive electrode tab; 320, negative electrode tab. Detailed Implementation

[0020] 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.

[0021] It should be noted that if multiple embodiments of this application involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators 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 indicators will also change accordingly.

[0022] 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.

[0023] In battery cells of relevant technologies, the positive and negative tabs of the inner core are usually led out from the end of the cell and then bent inward and welded to the base plate of the pole on the inside of the cover plate. In order to avoid the pole, connecting piece and welding area, the tab and its bending space must remain inside the shell. This redundant structure of bending and welding directly occupies the effective height of the inner cavity, which restricts the length of the inner core's electrode, prevents the active material from being fully filled, and reduces the energy storage capacity per unit volume.

[0024] The space utilization rate of the battery cell's internal cavity directly affects the volumetric energy density of the battery cell. Improving space utilization is beneficial for increasing battery energy density and reducing manufacturing costs. Currently, the core in a battery cell is usually led out through tabs and welded to the bottom plate of the terminal post on the casing cover. This means that after the tabs and / or connecting pieces are folded up and welded, they need to occupy part of the space inside the casing, resulting in a decrease in the internal space utilization rate of the battery cell.

[0025] To address the aforementioned problems, this application proposes a cover plate assembly 100 to solve the technical issues mentioned above.

[0026] Please see Figure 1 The cover plate assembly 100 includes a cover plate 1, a lower plastic 2 and a protrusion 3. The cover plate 1 has a first hole 1a. The lower plastic 2 is stacked with the cover plate 1. The lower plastic 2 has a protrusion 3 at one end near the cover plate 1 along a first direction. The protrusion 3 has a channel 3a. The protrusion 3 is disposed through the first hole 1a. The channel 3a is used for the lead-out of the electrode tab.

[0027] Please continue reading. Figure 1 and combined Figure 7 It is understandable that, in the first direction, which is perpendicular to the cover plate 1, the channel 3a formed on the protrusion 3 directly constitutes the path connecting the internal space of the battery cell 1000 with the external mounting cavity 4a. This allows the positive electrode tab 310 and negative electrode tab 320 of the inner core 300 to be gathered and welded together, and finally led out from the channel 3a to the mounting cavity 4a. The channel 3a formed in the protrusion 3 and the mounting cavity 4a formed in the protective cap 4 together form an externally sealed space for accommodating and installing the positive electrode tab 310 and negative electrode tab 320 of the inner core 300. This design avoids the problem of too many tabs occupying the limited space inside the housing 200, and also ensures the good sealing performance of the housing 200, preventing the intrusion of external moisture and dust.

[0028] The protrusion 3 is made of insulating material. By using a metal cover plate 1 (i.e., a plain aluminum sheet) to pass through the protrusion 3, it is possible to prevent the side of the tab from contacting the cover plate 1 when it is led out, thus avoiding a short circuit between the positive tab 310 and the negative tab 320 through the metal cover plate 1. This further ensures the safety and reliability of the cover plate assembly 100 and reduces safety hazards. At the same time, the protrusion 3 also provides good fixation and support for the tabs around its perimeter, preventing deformation of the tabs due to long-term use and affecting the electrical performance of the battery. Moreover, the protrusion 3 can also prevent external moisture condensation from entering the interior of the casing 200 through gaps, maintaining a stable internal insulation environment and fundamentally reducing the occurrence of safety problems such as short circuits.

[0029] It should be noted that the overall shape of the protrusion can be cylindrical, polygonal, or irregularly shaped. This application does not limit this; any shape that can isolate the electrode tab from the cover plate 1 is within the scope of protection of this application. In one embodiment of this application, the protrusion 3 is generally rectangular, and the protrusion 3 has a rectangular channel 3a. For further details, please refer to [the relevant documentation]. Figure 1 The protrusion 3 adopts a cuboid shape, which can make full use of the straight segment space of the first hole 1a on the cover plate 1. When it is matched with the rectangular cut, the force is even on all four sides, and the resistance to rotation and lateral displacement is good. At the same time, the cuboid shape is easy to injection mold, which is conducive to batch assembly and maintaining the centering of the tab.

[0030] Specifically, such as Figure 1As shown, channel 3a is designed with a rectangular cross-section, matching the natural shape of the flat tab. This reduces the number of bends and the bending radius of the tab, lowering stress concentration and the risk of breakage. The rectangular opening has no rounded dead corners, allowing for smooth tab insertion and facilitating subsequent direct welding or positioning via adapter piece 5, thus improving manufacturing efficiency and electrical reliability. The cuboid-shaped protrusion 3 and the rectangular channel 3a form a nested structure, allowing for one-time positioning to complete the outer shape and inner cavity. This process is simple and ensures good coaxiality. During assembly, the tab is guided along a straight line with uniform gaps around it and a constant insulation distance. This avoids short circuits with the metal cover plate 1 and fully utilizes the height space, allowing the folded-up portion of the tab to be completely moved outside the cover. This maximizes the usable height inside the battery, simultaneously improving energy density and safety.

[0031] In this application, a protrusion 3 is provided at one end of the lower plastic 2 near the cover plate 1 along a first direction, and a channel 3a is formed within the protrusion 3. This allows the tabs to extend into the channel 3a, thereby preventing the tabs from retracting within the housing 200 and occupying the limited space within the housing 200, thus improving the energy density of the battery cell 1000 per unit volume. Specifically, the cover plate assembly 100 includes a cover plate 1, a lower plastic 2, and a protrusion 3. The cover plate 1 has a first hole 1a. The lower plastic 2 is stacked with the cover plate 1. The lower plastic 2 has a protrusion 3 at one end near the cover plate 1 along the first direction. The protrusion 3 has a channel 3a, which extends through the first hole 1a. The channel 3a is used for the tabs to be led out. After the battery is assembled, the tabs at the end of the inner core 300 are accommodated within the channel 3a without occupying the limited space within the housing 200, thus improving the internal space utilization of the battery cell 1000. Moreover, the protrusion achieves physical isolation between the tab and the cover plate 1, preventing the tab from contacting the cover plate 1 and causing a short circuit in the battery.

[0032] To ensure that the tabs can be isolated from the cover plate 1, the height of the protrusion 3 must be greater than or equal to the thickness of the cover plate 1, so as to ensure that the tabs do not come into contact with the metal cover plate 1. Since the protrusion 3 and the lower plastic 2 are an integral structure, its design reference should be the plane of the lower plastic 2 near the end of the cover plate 1 along the first direction.

[0033] Specifically, please refer to Figure 6The distance between the end face of the protrusion 3 away from the lower plastic 2 along the first direction and the end face of the lower plastic 2 near the cover plate 1 along the first direction is equal to the thickness H1 of the protrusion 3 along the first direction being greater than or equal to the thickness H2 of the cover plate 1 along the first direction. During the design, the top surface of the lower plastic 2 is used as the zero reference. First, the theoretical dimension H of the distance from the end face of the cover plate 1 away from the lower plastic 2 along the first direction to the reference surface is calculated based on the thickness of the cover plate 1. Then, the height of the protrusion 3 (the distance from the end face of the protrusion 3 away from the lower plastic 2 along the first direction to the reference surface) is directly taken as H or a certain safety margin is added, allowing for one-time injection molding. This design ensures that the end face of the protrusion 3 away from the lower plastic 2 along the first direction is always no lower than the end face of the cover plate 1 away from the lower plastic 2 along the first direction. During insertion, bending, or welding, the electrode tab will not touch the metal cover plate 1 at any point, fundamentally eliminating the risk of short circuit between the positive and negative electrodes through the cover plate 1. It also eliminates the need for additional insulating gaskets and secondary assembly, reducing the number of parts and improving installation efficiency.

[0034] Please see Figure 4 and combined Figure 5 To prevent the positive electrode tab 310 and negative electrode tab 320 from being exposed and to prevent external moisture and particulate matter from entering the casing 200 and causing battery failure, the channel 3a needs to be designed as a closed structure. That is, the channel 3a is connected to the inner cavity of the casing 200, but not to the outside. The end of the protrusion 3 away from the inner core 300 can be designed as a blind end, or the channel 3a can be filled with sealant 9, or a cover structure can be provided on the side of the cover plate 1 facing away from the plastic 2, thereby forming a receiving cavity 4a that can communicate with the inside of the casing 200. This application does not limit the specific structure used to isolate the channel 3a from the outside. In one embodiment of this application, a protective cap 4 is provided on the side of the cover plate 1 facing away from the plastic 2. The protective cap 4 can provide physical protection for the protrusion 3 and the tabs located in the channel 3a, preventing the tabs from being deformed or broken by external impact, and at the same time preventing external dust, impurities and other particulate matter from contacting the tabs, ensuring the structural integrity and conductivity reliability of the tabs. Secondly, in terms of sealing performance, the protective cap 4 and the cover plate 1 form a receiving cavity 4a, which can effectively isolate the channel 3a from the outside world, prevent external moisture from entering the battery, avoid the reaction between moisture and internal battery components leading to battery failure, ensure the sealing of the internal environment of the battery, and maintain the normal working state of the battery.

[0035] To prevent the protrusion 3 from exceeding its height too much, which would prevent the protective cap 4 from being properly assembled, the inner end face 4b of the protective cap 4 facing the protrusion 3 is higher than the upper end face 3b of the protrusion 3. The distance between the upper end face 3b of the protrusion 3 and the end of the cover plate 1 away from the lower plastic 2 along the first direction is less than or equal to the distance between the inner end face 4b of the protective cap 4 and the end of the cover plate 1 away from the lower plastic 2 along the first direction. In this way, the upper end face 3b of the protrusion 3 will not be higher than the inner end face 4b of the protective cap 4, and the protective cap 4 can be smoothly fastened to the cover plate 1 without the need to deepen the cap cavity. This saves material and height space for the protective cap 4, and ensures that the electrode tab is always insulated and wrapped within the receiving cavity 4a. It also provides greater assembly tolerance, a smooth appearance, and avoids the risk of deformation or sealing failure of the protective cap 4.

[0036] Please continue reading. Figure 4 In some embodiments, the protective cap 4 is not connected to the cover plate 1, but is directly engaged with the portion of the protrusion 3 that is higher than the cover plate 1. Specifically, the outer diameter of the protrusion 3 is greater than or equal to the inner diameter of the protective cap 4, thereby forming an interference fit between the protective cap 4 and the protrusion 3. This simplifies the assembly process of the protective cap 4 and also provides protection for the electrode tabs.

[0037] Please continue reading. Figure 4 To provide physical protection for the protrusion 3 and the positive and negative electrodes located in the channel 3a, and to prevent deformation caused by external impact, the protective cap 4 is made of metal. The inner side of the protective cap 4, that is, the side facing the protrusion 3, is coated with an insulating layer 41. Specifically, the metal protective cap 4 can withstand external impact, preventing the protrusion 3 and the electrodes from deforming or breaking due to collision, ensuring the integrity of the product structure and the reliability of conductivity; the inner insulating layer 41 can block the electrical contact between the protective cap 4 and the electrodes, preventing the cover plate 1 from becoming energized or the positive and negative electrodes from short-circuiting, thus balancing mechanical strength and electrical safety.

[0038] It should be noted that the protective cap 4 can be installed on the side of the cover plate 1 facing away from the plastic 2 by means of bonding, welding, snap-fitting, etc. This application does not limit this. In one embodiment of this application, the protective cap 4 is made of the same material as the cover plate 1, and the two are welded together. The protective cap 4 is made of the same aluminum or aluminum alloy material as the cover plate 1 and is directly laser welded. The two have the same coefficient of thermal expansion, and the weld is fatigue-resistant, vibration-resistant and has good sealing performance, eliminating the need for sealing rings and fasteners. Welding with the same material can also form a continuous conductive path, reduce contact impedance and improve shielding effect, while simplifying material management, reducing assembly processes, and achieving a low-cost, high-reliability integrated cap.

[0039] Specifically, to improve installation reliability, the protective cap 4 is provided with a raised edge around its perimeter. The raised edge forms a widened annular contact surface between the protective cap 4 and the cover plate 1. During laser welding, the molten pool area expands accordingly, and the weld's resistance to shearing and peeling is enhanced. Even if the battery is subjected to long-term vibration or thermal cycling, it is not easy to crack. At the same time, the raised edge can also serve as a positioning step, automatically centering and flattening during assembly, reducing the welding gap, reducing the probability of incomplete welding and porosity, thereby improving the connection strength and sealing reliability.

[0040] In some embodiments, such as Figure 1 As shown, the cover plate assembly 100 also includes a positive terminal 6 and a negative terminal 7, both of which penetrate the cover plate 1 and the lower plastic 2. For details, please refer to further documentation. Figure 5 and combined Figure 6 The cover plate 1 has a first hole 1a near the positive terminal 6 and the negative terminal 7, respectively. Correspondingly, the cover plate assembly 100 also includes two protrusions 3, each with a channel 3a. The cover plate assembly 100 includes two protective caps 4, each corresponding to a protrusion 3. The protective caps 4 and the cover plate 1 together form two isolated receiving cavities 4a, which are used to receive the positive terminal tab 310 and the negative terminal tab 320, respectively. Separately receiving and installing the positive terminal tab 310 and the negative terminal tab 320 further improves the safety and reliability of the battery.

[0041] like Figure 1 and Figure 8 As shown, since part of the tab structure of the inner core 300 is located in the channel 3a of the protrusion 3, and the positive electrode post 6 and negative electrode post 7 of the cover plate assembly 100 are not directly connected to the tab, in order to realize the connection between the tab and the post, an adapter piece 5 is provided between the positive electrode post 6 and the positive electrode tab 310, and an adapter piece 5 is also provided between the negative electrode post 7 and the negative electrode tab 320.

[0042] Please see Figure 3This application does not limit the specific shape, size, or material of the adapter piece 5. In one embodiment of this application, the adapter piece 5 and the adapter piece 5 used to connect the negative electrode post 7 and the negative electrode tab 320 are arranged symmetrically along an axis. Specifically, the adapter piece 5 mainly includes two parts: a bent portion 51 and an extension portion 52. The extension portion 52 is elongated and extends along the length direction of the cover plate 1. The bent portion 51 includes a first bent segment 511 and a second bent segment 512 connected to each other. The first bent segment 511 and the second bent segment 512 are perpendicular to each other, and the first bent segment 511 extends along the length direction of the cover plate 1, while the second bent segment 512 extends along a first direction. In actual installation, taking the positive electrode tab 310 and the positive electrode post 6 as an example, the extension is welded to the base plate of the positive electrode post 6, the second bending section 512 of the bending part 51 is welded to the positive electrode tab 310, and together they are accommodated in the channel 3a, so as to achieve a reliable connection and conduction between the positive electrode tab 310 and the positive electrode post 6. The connection method between the negative electrode post 7 and the negative electrode tab 320 is the same as that of the positive electrode post 6, and will not be described again here.

[0043] The irregularly shaped adapter piece 5 uses the zigzag configuration of the bending part 51 and the extension part 52 to complete the transition between the height difference and the direction difference between the pole and the pole in one go: the extension part 52 extends horizontally along the length of the cover plate 1 and can directly overlap the pole base plate, reducing the welding difficulty; the bending part 51 is folded vertically and in the same direction as the closed pole, and can penetrate into the channel 3a of the protrusion 3 to fit and weld with the pole, reducing the number of bends and stress concentration; the zigzag structure itself also forms an elastic buffer section, which can absorb vibration and thermal expansion deformation and avoid weld tearing; the symmetrical arrangement of the positive and negative pieces makes the weight and current distribution balanced, simplifies tooling positioning, and takes into account electrical performance, reliability and assembly efficiency.

[0044] Furthermore, to avoid the adapter piece 5 occupying the limited space within the housing 200, the extension 52 should be designed to be as flat and thin as possible. By making the extension 52 into a flat and thin strip shape, it can extend close to the lower surface of the cover plate 1 without encroaching on the height of the cell downwards. This maximizes the length of the electrode plate left in the inner cavity of the housing 200, thereby increasing the volumetric energy density. At the same time, the cross-sectional area is still sufficient to carry the rated current, the temperature rise is controllable, and the thin structure also reduces the amount of material used and the weight, achieving a balance between lightweight, high capacity, and low cost.

[0045] Please see Figure 1 To prevent battery explosion or deflagration caused by thermal runaway, the cover plate 1 is provided with an explosion-proof port located between the two first holes 1a. The battery cell 100 also includes an explosion-proof valve 8, which is located at the explosion-proof port. For details, please refer to further documentation. Figure 1The explosion-proof valve 8 is a disposable pressure relief device. Under normal conditions, it is sealed by a metal or plastic diaphragm to maintain the isolation between the inside and outside of the battery. When internal short circuits, overcharging, or other factors cause thermal runaway, the gas pressure rises sharply to a preset value, and the diaphragm ruptures or flips instantly. The high-pressure gas is quickly discharged through the explosion-proof port, preventing the casing 200 from continuing to rise in pressure and explode. After depressurization, the diaphragm remains open and does not reset, thus clearly indicating to the outside that the battery has failed, while preventing air backflow and reducing the risk of subsequent combustion. The explosion-proof valve 8 uses a thin diaphragm instead of the entire casing 200 to withstand the ultimate pressure. It is small in size and low in cost, yet it can rupture precisely within milliseconds of thermal runaway, directionally discharging high-pressure, high-temperature gas. This prevents the casing 200 from exploding and splashing, and also prevents oxygen backflow that fuels combustion. At the same time, the opening of the valve body forms an irreversible failure mark, which facilitates rapid identification of problematic batteries by the backend, taking into account safety, maintenance, and traceability requirements.

[0046] Please continue reading. Figure 1 To prevent the lower plastic 2 from obstructing the discharge of runaway gas and liquid through the explosion-proof valve 8 outside the housing 200, the lower plastic 2 is provided with flow holes 2a, which connect the explosion-proof port and the inside of the battery. Multiple flow holes 2a arranged in an array are provided in the middle area of ​​the lower plastic 2, ensuring that the projection of the explosion-proof valve 8 on the lower plastic 2 falls within the area formed by the multiple flow holes 2a. This arrangement allows the pressure relief channel 3a of the explosion-proof valve 8 to extend directly into the battery core. In the event of thermal runaway, high-pressure gas and electrolyte can instantly reach the explosion-proof valve 8 without detours, shortening the pressure relief time and reducing peak pressure. Simultaneously, it prevents the plastic separator from being cracked or blocked by fragments, ensuring smooth drainage and air release, improving explosion-proof reliability, and reducing secondary debris hazards.

[0047] This application also proposes a battery cell 1000; please refer to further details. Figure 7 and Figure 8 The battery cell 1000 includes a housing 200, a cover assembly 100, and an inner core 300. The housing 200 has a first opening, the cover assembly 100 is disposed in the first opening, and the inner core 300 is disposed inside the housing 200. One end of the inner core 300 is provided with a positive electrode tab 310 and a negative electrode tab 320. The positive electrode tab 310 is disposed in a channel 3a, and the negative electrode tab 320 is disposed in another channel.

[0048] Please see Figure 7 and combined Figure 8Understandably, the specific assembly steps for the battery cell 1000 are as follows: First, the inner core 300 is installed into the housing 200, then the lower plastic 2 and the cover plate 1 are installed in sequence, ensuring that the positive electrode tab 310 and the negative electrode tab 320 of the inner core 300 pass through the two channels 3a respectively. An adapter piece 5 is placed between the positive electrode tab 310 and the positive electrode post 6, and an adapter piece 5 is placed between the negative electrode tab 320 and the negative electrode post 7 to ensure reliable electrical connection. Then, laser welding is performed at the joint between the cover plate 1 and the housing 200 to make them a single unit. Finally, the tabs are neatly arranged to ensure they are installed in a certain regularity within the channels 3a, and a protective cap 4 is placed over the protrusion 3 and welded to the cover plate 1, thus completing the assembly of the battery cell 1000. Then, electrolyte is added to the housing 200.

[0049] It should be noted that the inner core 300 can be a wound structure or a stacked structure, and this application does not limit it in this regard.

[0050] 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 cover plate assembly, characterized in that, include: Cover plate (1) having a first hole (1a); The lower plastic (2) is stacked with the cover plate (1). The lower plastic (2) has a protrusion (3) at one end near the cover plate (1) along the first direction. The protrusion (3) has a channel (3a) and the protrusion (3) is disposed through the first hole (1a). The channel (3a) is used for the lead-out of the electrode tab.

2. The cover plate assembly as claimed in claim 1, characterized in that, The thickness of the protrusion (3) along the first direction is greater than or equal to the thickness of the cover plate (1) along the first direction.

3. The cover plate assembly as claimed in claim 1, characterized in that, The cover plate assembly further includes an adapter piece (5), which includes a bent portion (51) and an extension portion (52). The bent portion (51) includes a first bent section (511) and a second bent section (512) connected to each other. The first bent section (511) is connected to the extension portion (52), and the second bent section (512) is connected to the tab. At least a portion of the structure of the second bent section (512) is disposed within the channel (3a).

4. The cover plate assembly as described in any one of claims 1 to 3, characterized in that, The cover plate assembly also includes a protective cap (4), which is disposed on the cover plate (1); the protective cap (4) and the cover plate (1) enclose a receiving cavity (4a), the channel (3a) is connected to the receiving cavity (4a), and the receiving cavity (4a) is used to receive the electrode tab.

5. The cover plate assembly as claimed in claim 4, characterized in that, The protective cap (4) has an insulating layer (41) at one end along the first direction near the protrusion (3).

6. The cover plate assembly as claimed in claim 5, characterized in that, The inner diameter of the protective cap (4) is less than or equal to the outer diameter of the protrusion (3), and the protective cap (4) is engaged with the protrusion (3).

7. The cover plate assembly as claimed in any one of claims 1 to 3, characterized in that, The channel (3a) is filled with sealant (9) to prevent the channel (3a) from communicating with the outside world.

8. The cover plate assembly as described in any one of claims 1 to 3, characterized in that, The cover plate assembly further includes a positive electrode post (6) and a negative electrode post (7). The positive electrode post (6) is disposed through the cover plate (1) and the lower plastic (2), and the negative electrode post (7) is disposed through the cover plate (1) and the lower plastic (2).

9. The cover plate assembly as claimed in any one of claims 1 to 3, characterized in that, The cover plate (1) has an explosion-proof port located between the two first holes (1a). The cover plate assembly also includes an explosion-proof valve (8) located at the explosion-proof port. The lower plastic (2) has a flow hole (2a), and the projection of the explosion-proof port on the lower plastic (2) coincides with the flow hole (2a).

10. A single battery cell, characterized in that, include: The housing (200) has a first opening; The cover assembly (100) as described in any one of claims 1 to 9 is disposed at the first opening; An inner core (300) is disposed within the housing (200). One end of the inner core (300) is provided with a positive electrode tab (310) and a negative electrode tab (320). The positive electrode tab (310) is disposed in one of the channels (3a), and the negative electrode tab (320) is disposed in the other channel (3a).

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