Battery cell cover plate and battery

Abstract

The invention relates to the technical field of batteries, and provides a battery cell cover plate and a battery, the battery cell cover plate comprises a cover plate body, a pole, a connecting sheet and a lower plastic part, the cover plate body is provided with an accommodating cavity, and the accommodating cavity is provided with an opening facing one side of the inner surface of the cover plate body; the pole penetrates through the cover plate body; the connecting sheet is arranged on one side of the inner surface of the cover plate body, one end of the connecting sheet is connected to the pole, and the other end of the connecting sheet extends to the accommodating cavity; the lower plastic part comprises a lower plastic main body and a moving part, the lower plastic main body is arranged on the inner surface of the cover plate body, the moving part is provided with a pressing part, and the moving part is movably connected to the lower plastic main body and is suitable for moving between a first position and a second position; when the moving part is at the second position, the pressing part moves out of the accommodating cavity; the moving part moves to the first position and is pressed on one side, deviating from the cover plate body, of the lower plastic main body, and the pressing part extends into the accommodating cavity to limit the tab, so that the reliability and the safety of electrical connection in the battery cell are improved.

Description

Technical Field

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

[0002] Lithium-ion batteries are widely used in various fields such as transportation power supply, power storage, new energy storage power supply, aerospace and military industry due to their advantages such as large capacity, high operating voltage, strong charge retention capability and long cycle life.

[0003] In existing technologies, the basic unit of a lithium-ion battery is the cell, which typically consists of electrode arrays, electrolyte, cell casing, cover plate, and necessary insulation and safety components. The cover plate, as a key component of the cell, integrates structures such as terminals and explosion-proof valves. It forms a sealed space by welding to the casing, and the tabs leading from the internal electrode arrays are electrically connected to the terminals via connecting tabs.

[0004] However, during battery transportation or use, there are issues with the reliability of internal electrical connections, which can easily lead to increased internal resistance or momentary circuit breaks, thereby affecting battery safety performance. Summary of the Invention

[0005] This invention provides a cell cover and a battery to solve the defects of poor electrical connection reliability in the prior art that affect safety performance. It enables the tabs to be limited and prevents them from shaking inside the casing, thereby improving the reliability and safety of the battery's electrical connection.

[0006] This invention provides a battery cell cover plate, comprising: The cover plate body has a receiving cavity, and the receiving cavity has an opening facing the inner surface of the cover plate body; The pole is inserted into the cover plate body; A connecting piece is disposed on the inner side of the cover plate body. One end of the connecting piece is connected to the pole post, and the other end of the connecting piece extends to the receiving cavity for connection with the electrode tab. The lower molding component includes a lower molding body and a movable component. The lower molding body is disposed on the inner surface of the cover plate body. The movable component is provided with a pressing part. The movable component is movably connected to the lower molding body and is adapted to move between a first position and a second position. In the first position, the movable component presses against the side of the lower molding body away from the cover plate body, and the pressing part extends into the receiving cavity to press the electrode tab into the receiving cavity. In the second position, the pressing part moves out of the receiving cavity.

[0007] According to the present invention, a battery cell cover plate is provided with a protrusion on the outer surface of the cover plate body, and the receiving cavity is formed by the inner surface of the cover plate body recessing towards the outer surface and extending into the protrusion.

[0008] According to a battery cell cover provided by the present invention, the height of the electrode post extending from the outer surface of the cover body is lower than the height of the protrusion.

[0009] According to the present invention, the height of the pressing part in the thickness direction of the lower plastic body is adapted to the difference between the depth of the receiving cavity and the thickness of the connecting piece and the electrode tab.

[0010] According to the present invention, the height H3 of the pressing part is in the range of 1.2 mm ≤ H3 ≤ 3.5 mm.

[0011] According to a battery cell cover plate provided by the present invention, in the first position, the projection of the welding area between the electrode tab and the connecting piece along the thickness direction of the cover plate body is located within the contour range of the pressing part.

[0012] According to the present invention, a battery cell cover plate is provided, wherein the receiving cavity is disposed along the length direction of the cover plate body and is located in the middle of the cover plate body; There are two pole posts, which are disposed at both ends of the cover plate body along the length direction; There are two connecting pieces. The first end of each connecting piece is connected to one of the two pole posts, and the second end of each connecting piece extends into the receiving cavity to connect to the two pole tabs respectively. There are two movable parts, which are respectively movably connected to both ends of the lower plastic body in the length direction. The pressing part on each movable part is adapted to extend into the receiving cavity to press the two tabs into the receiving cavity respectively.

[0013] According to the present invention, a battery cell cover plate is provided, wherein the lower plastic body is provided with a first positioning part, and the moving part is provided with a second positioning part; At the first position, the first positioning part and the second positioning part abut against each other.

[0014] According to a battery cell cover plate provided by the present invention, the connecting piece includes a first connecting portion, a bending portion and a second connecting portion connected in sequence, the first connecting portion is connected to the electrode post, the bending portion extends toward the outer surface of the cover plate body, and the second connecting portion is located in the receiving cavity.

[0015] The present invention also provides a battery comprising: Battery cell casing; And a cell cover as described in any of the above, wherein the cell cover and the cell housing form a sealed space; The electrode assembly is located in the sealed space and is electrically connected to the cell cover plate.

[0016] The battery cell cover provided by this invention features a receiving cavity with an opening facing the inner surface on the cover body. One end of a connecting piece is fixedly connected to a terminal post penetrating the cover body, while the other end extends into the receiving cavity for electrical connection with the battery cell's tab. Simultaneously, a movable component is provided on the inner surface of the cover body. During assembly, the movable component is in a second position, with the pressing part moving out of the receiving cavity, facilitating the insertion of the tab into the receiving cavity and connection with the connecting piece. After assembly, the movable component moves to a first position, pressing against the side of the lower plastic body away from the cover body. At this point, the pressing part extends into the receiving cavity, pressing the tab firmly within the cavity. This limits the tab's position, preventing it from shaking within the battery casing due to vibration or external forces during transportation, thereby improving the reliability and safety of the internal electrical connections of the battery cell. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in this invention 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 some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is one of the structural schematic diagrams of the battery provided by the present invention.

[0019] Figure 2 This is the second schematic diagram of the battery structure provided by the present invention.

[0020] Figure 3 This is one of the structural schematic diagrams of the battery cell cover plate provided by the present invention.

[0021] Figure 4 This is the second schematic diagram of the structure of the battery cell cover plate provided by the present invention.

[0022] Figure 5 This is the third schematic diagram of the structure of the battery cell cover plate provided by the present invention.

[0023] Figure 6 This is the fourth schematic diagram of the structure of the battery cell cover plate provided by the present invention.

[0024] Figure 7 This is the fifth schematic diagram of the structure of the battery cell cover plate provided by the present invention.

[0025] Figure 8 This is the sixth schematic diagram of the structure of the battery cell cover plate provided by the present invention.

[0026] Figure 9 This is a cross-sectional view of the battery cell cover plate provided by the present invention.

[0027] Figure 10This is the third schematic diagram of the battery structure provided by the present invention.

[0028] Figure 11 This is the seventh schematic diagram of the structure of the battery cell cover plate provided by the present invention.

[0029] Figure label: 100. Cell cover plate; 110. Cover plate body; 111. Protrusion; 112. Receiving cavity; 113. Pole post hole; 114. Explosion-proof valve hole; 115. Liquid injection hole; 120. Pole column; 130. Connecting piece; 131. First connecting part; 132. Bending part; 133. Second connecting part; 134. Welding part; 140. Lower molding component; 141. Lower molding body; 142. Moving part; 1421. Pressing part; 200. Battery cell casing; 300, electrode group; 310, electrode tab. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0031] In the description of the embodiments of the present invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the present invention. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0032] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention based on the specific circumstances.

[0033] In embodiments of the present invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0034] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0035] The following is combined Figures 1-11 The present invention describes the cell cover plate.

[0036] An embodiment of the first aspect of the present invention provides a cell cover plate, such as Figures 3 to 8 ,as well as Figure 10 As shown, the cell cover 100 includes a cover body 110 and an electrode post 120, a connecting piece 130 and a lower molding component 140 integrated on the cover body 110.

[0037] The cover plate body 110 has opposing outer and inner surfaces. The cover plate body 110 has a receiving cavity 112 with an opening facing the inner surface of the cover plate body 110. A pole post 120 passes through the cover plate body 110. A connecting piece 130 is disposed on the inner surface of the cover plate body 110, with one end connected to the pole post 120 and the other end extending into the receiving cavity 112 for connection with the electrode tab 310. The lower molding component 140 includes a lower molding body 141 and a moving member 142. The lower molding body 141 is disposed on the inner surface of the cover plate body 110, and the moving member 142 has a pressing part 1421. The moving member 142 is movably connected to the lower molding body 141 and is adapted to move between a first position and a second position. Figure 3 and Figure 4As shown, in the first position, the movable member 142 presses against the side of the lower plastic body 141 away from the cover plate body, and the pressing part 1421 extends into the receiving cavity 112 to press the tab 310 into the receiving cavity 112; as Figures 5 to 8 As shown, in the second position, the clamping part 1421 moves out of the receiving cavity 112.

[0038] It is understood that by providing a receiving cavity 112 with an opening facing the inner surface on the cover plate body 110, and fixing one end of the connecting piece 130 to the pole post 120 that penetrates the cover plate body 110, and extending the other end into the receiving cavity 112, it is used to achieve electrical connection with the electrode tab 310 of the battery cell; at the same time, a lower molding component 140 is provided on the inner surface of the cover plate body 110, the lower molding component 140 has a movable member 142 that is movably connected, the movable member 142 is provided with a pressing part 1421, and the movable member 142 can move relative to the cover plate body 110 between a first position and a second position. During assembly, the movable part 142 is in the second position, and the clamping part 1421 is removed from the receiving cavity 112, so that the electrode 310 can be inserted into the receiving cavity 112 and aligned with the connecting piece 130. After assembly, the movable part 142 moves to the first position and is clamped on the side of the lower plastic body 141 away from the cover plate body. At this time, the clamping part 1421 extends into the receiving cavity 112 and firmly clamps the electrode 310 in the receiving cavity 112 to achieve the dual function of mechanical fixation and electrical conduction.

[0039] It should be noted that the connecting piece 130 is disposed on the inner side of the cover plate body 110 and connected to the pole post 120. The lower molding body 141 is attached to the inner surface of the cover plate body 110. Thus, the lower molding body 141 is located between the inner surface of the cover plate body 110 and the connecting piece 130 (the area of ​​the connecting piece 130 connected to the pole post 120). When the moving member 142 is in the first position, the moving member 142 is pressed against the area of ​​the connecting piece 130 connected to the pole post 120. Figure 1 and Figure 2 As shown, the cell cover plate 100 is sealed to the cell housing 200. The outer surface of the cover plate body 110 is the side surface away from the inside of the cell housing 200, and the inner surface of the cover plate body 110 is the side surface close to the inside of the cell housing 200.

[0040] It should be noted that if the tab 310 is not securely fixed inside the battery, it will shake during use. This shaking can directly cause the tab 310 to tear due to stress concentration, and may also cause misalignment and reverse insertion. The accumulation of these damages will lead to a significant increase in the battery's internal resistance, and a sudden severe tear or reverse insertion can cause a momentary circuit break, resulting in battery failure and safety hazards. Based on this discovery, the present invention provides a clamping part 1421 in the lower molding component 140 to apply pressure to the tab 310 in the receiving cavity 112, thereby reliably limiting the tab 310 and effectively preventing the tab 310 from shaking due to vibration during battery use or transportation. This avoids problems such as stress concentration or poor soldering at the tab 310 connection, thereby ensuring the reliability of the internal electrical connection of the cell, reducing the risk of increased internal resistance or momentary circuit breakage, and improving battery safety.

[0041] The battery cell cover provided in this embodiment of the invention has a receiving cavity 112 with an opening facing the inner surface on the cover body 110, and one end of the connecting piece 130 is fixedly connected to the electrode post 120 penetrating the cover body 110, while the other end extends into the receiving cavity 112 for electrical connection with the electrode tab 310 of the battery cell; at the same time, a movable moving part 142 is provided on the inner surface of the cover body 110. During the assembly process, the moving part 142 is in a second position, and the pressing part 1421 moves out of the receiving cavity 112. 2. This facilitates the insertion of the tab 310 into the receiving cavity 112 and its connection to the connecting piece 130. After assembly, the moving part 142 moves to the first position and presses against the side of the lower plastic body 141 away from the cover plate body. At this time, the pressing part 1421 extends into the receiving cavity 112 and presses the tab 310 into the receiving cavity 112. This effectively limits the tab 310 and prevents it from shaking inside the battery casing due to vibration or external forces during transportation, thereby improving the reliability and safety of the internal electrical connection of the battery cell.

[0042] In one embodiment of the present invention, the pressing part 1421 is a recessed platform, and the height of the recessed platform in the thickness direction of the lower plastic body 141 is adapted to the difference between the depth of the receiving cavity 112 and the thickness of the connecting piece 130 and the tab 310.

[0043] Understandably, by designing the clamping part 1421 as a recessed platform and controlling its height, it is ensured that when the clamping part 1421 clamps the tab 310, it can provide just the right preload force, which can firmly fix the tab 310 and prevent it from loosening, without damaging the tab 310 or its welding area with the connecting piece 130 due to excessive pressure, thus achieving the best clamping effect and ensuring the long-term stability of the connection.

[0044] In this embodiment, the height H3 of the sinking platform can be designed to be 1.2 mm to 3.5 mm.

[0045] In one embodiment of the present invention, such as Figure 6 As shown, the lower surface of the connecting piece 130 located within the receiving cavity 112 (the side surface closest to the interior of the cell housing 200) is provided with a welding portion 134 for connecting with the tab 310. The welding portion 134 can be a welding protrusion provided on the lower surface of the connecting piece 130. Two welding protrusions are arranged at intervals along the width direction of the cover plate body 110 on each connecting piece 130, and each welding protrusion extends along the length direction of the cover plate body 110 to increase the welding contact area and improve the connection strength. During assembly, the two tabs 310 of each electrode group 300 are inserted vertically, bent from the lower direction of the connecting piece 130 towards each other, and attached to the lower surface of the connecting piece 130 (the tab portion attached to the lower surface of the connecting piece 130 serves as the tab connection portion), covering the welding protrusion area. Subsequently, the lower surface of the connecting piece 130 and the tab connection portion are welded and fixed by welding, thereby realizing the connection between the connecting piece 130 and the tab 310 inside the receiving cavity 112. Simultaneously, the clamping action of the movable part 142 further prevents the electrode tab 310 from shifting or loosening after welding, ensuring the reliability of the connection quality. It should be noted that when the movable part 142 is in the first position, the electrode tab 310 and the connecting piece 130 are pressed between the bottom wall of the receiving cavity 112 and the clamping part 1421.

[0046] It should be noted that the welding part 134 can also be provided on the upper surface of the connecting piece 130 in the receiving cavity 112 (the side surface away from the inside of the cell housing 200). The two tabs 310 of each pole group 300 can also be inserted vertically, passing through the gap between the connecting piece 130 and the side wall of the receiving cavity 112, and the two tabs (i.e., the tab connecting parts) extending from the top of the connecting piece 130 are bent towards each other, so that they fit against the upper surface of the connecting piece 130 and cover the welding protrusion area, so that the tabs 310 are connected to the upper surface of the connecting piece 130.

[0047] Optionally, when the movable part 142 is in the first position, the projection of the welding area between the tab 310 and the connecting piece 130 in the thickness direction of the cover plate body 110 falls within the contour range of the pressing part 1421. The welding area is the area covered by the outer contour of the welding part 134 on the connecting piece 130, for example, the entire area formed by the two welding protrusions on the connecting piece 130. This allows the pressing part 1421 to apply a direct pressing force to the welding area, effectively covering and protecting the welded connection, preventing the tab 310 from warping, detaching, or experiencing fretting wear due to external force or vibration after welding. This further improves the mechanical stability and electrical reliability of the connection, ensuring the safety of the battery during long-term use.

[0048] In this embodiment, the total welding area on each connecting piece 130 is S4, in mm. 2 The total welding area is the sum of the cross-sectional areas of the welded portions 134 on the connecting piece 130, that is, the sum of the cross-sectional areas of the two welded protrusions; the cross-sectional area of ​​the clamping portion 1421 is S5, in mm. 2 S4 and S5 satisfy: 0.35≤S4 / S5≤0.75.

[0049] According to an embodiment of the present invention, during the assembly of the battery cell, the moving part 142 is initially in the second position, at which time the clamping part 1421 retracts from the receiving cavity 112, providing working space for the installation and welding of the tab 310; subsequently, the tab 310 of the electrode assembly 300 is inserted into the receiving cavity 112 and aligned with the connecting piece 130 extending therein, and the tab 310 and the connecting piece 130 are completed by welding by bending the tab connecting part to the welding part 134 on the surface of the connecting piece 130. 0 is fixedly connected; after welding, the moving part 142 is moved to the first position along the inner surface of the cover plate body 110, and the pressing part 1421 is inserted into the receiving cavity 112, thereby pressing the welded electrode tab 310 between the connecting piece 130 and the receiving cavity 112 to achieve mechanical limiting and anti-loosening protection; then, the electrode group 300 is pressed upward so that it abuts against the surface of the positioned lower plastic part 140, and then the electrode group 300 is covered with an insulating film and installed as a whole into the cell housing 200.

[0050] In one embodiment of the present invention, such as Figures 5 to 8 As shown, the number of connecting pieces 130, pole posts 120, and moving parts 142 are the same, and their positions correspond one-to-one. Specifically, the receiving cavity 112 is located in the middle of the cover plate body 110; there are two pole posts 120, which are disposed at both ends of the cover plate body 110 along the length direction; there are two connecting pieces 130, one end of which is connected to the two pole posts 120 respectively, and the other end of each extends into the receiving cavity 112 to connect with the two tabs 310 respectively; there are two moving parts 142, which are rotatably connected to both ends of the lower plastic body 141 along the length direction, and the pressing part 1421 on each moving part 142 is adapted to extend into the receiving cavity 112 to press the two tabs 310 into the receiving cavity 112 respectively.

[0051] Understandably, the receiving cavity 112 is located in the middle region along the length of the cover plate body 110, and is used to centrally accommodate the connection portion between the electrode tab 310 and the connecting piece 130, which is beneficial for achieving a symmetrical layout and efficient utilization of internal space. Two pole posts 120 are respectively located at both ends of the cover plate body 110 along its length, penetrating the cover plate body 110 to achieve external electrical connection; correspondingly, two connecting pieces 130 are provided, one end of each connecting piece 130 being connected to the connection end of one pole post 120, and the other end of the connecting piece 130 extending into the receiving cavity 112 in the middle of the cover plate body 110, for electrical connection with the electrode tab 310 of the corresponding pole group 300. Simultaneously, two moving parts 142 are configured, movably connected to both ends of the cover plate body 110 along its length, each moving part 142 having a clamping part 1421, which can extend into or move out of the receiving cavity 112 as the moving part 142 rotates. When the two moving parts 142 move synchronously to the first position, their pressing parts 1421 extend into the receiving cavity 112, pressing the two tabs 310 located therein onto the corresponding connecting pieces 130, thereby achieving independent and synchronous pressing and fixing on both sides. The symmetrical double-end pressing structure of this embodiment not only improves the stability and reliability of the overall connection, but also balances the force, preventing stress concentration or connection misalignment caused by unilateral pressing, further ensuring the safety of the tab 310 connection.

[0052] It should be noted that the terminal post 120 is inserted through and fixed to the cover plate body 110. The terminal post 120 includes a working end and a connecting end. The working end is used to connect with the external circuit of the battery and is the interface for realizing the external output of battery power. The connecting end is connected to the electrode tab 310 of the electrode group 300 through the connecting piece 130 and is the input end for collecting internal current. The working end of the terminal post 120 and the outer surface of the cover plate body 110 are located on the same side.

[0053] Furthermore, an explosion-proof valve hole 114 is provided in the middle of the protrusion, which is used to install an explosion-proof valve.

[0054] In one embodiment of the present invention, the lower molding body 141 is provided with a first positioning part, and the moving part 142 is provided with a second positioning part; in a first position, the first positioning part and the second positioning part abut against each other.

[0055] Understandably, to ensure accurate positioning and reliable operation of the movable part 142 during movement, and to accurately stop at the first position to effectively press the tab 310, the lower molding body 141 is provided with a first positioning part, and the movable part 142 is correspondingly provided with a second positioning part. When the movable part 142 rotates to the first position, the first positioning part and the second positioning part cooperate to form a limiting or locking structure, thereby limiting the final installation position of the movable part 142. This positioning and cooperation relationship not only prevents the movable part 142 from shifting or rebounding due to vibration or external force, ensuring that the pressing part 1421 stably presses the tab 310 into the receiving cavity 112, but also provides clear positioning feedback during assembly.

[0056] The first positioning part and the second positioning part can be designed as matching bosses and grooves, buckles and holes, or mechanically cooperating structures such as guide ribs and limiting surfaces. They have the characteristics of simple structure, high reliability and no need for additional fasteners, which further enhances the overall connection safety of the battery cell cover 100.

[0057] Furthermore, the lower molding body 141 and / or the moving part 142 are provided with a locking structure for locking the moving part 142 in a first position.

[0058] Understandably, to ensure that the movable part 142 can be stably kept in a pressed state after reaching the first position, and to prevent it from loosening or displacing due to cell vibration, thermal expansion and contraction or mechanical impact, the lower molding body 141 is provided with a locking structure to reliably lock the movable part 142 in the first position. Of course, in other embodiments, the locking structure can also be provided on the movable part 142, or between the lower molding body 141 and the movable part 142. For example, a locking groove or limiting boss is provided on the inner surface of the lower molding body 141, and an elastic buckle or locking tongue is correspondingly provided on the movable part 142. When the movable part 142 moves to the first position, the locking tongue or buckle automatically engages with the locking groove or cooperates with the boss to form a mechanical self-locking, thereby ensuring that the pressing force on the tab 310 is continuously effective, and providing a guarantee for the electrical connection stability and safety of the battery.

[0059] In one embodiment of the present invention, such as Figure 9 As shown, a protrusion 111 is provided on the outer surface of the cover plate body 110, and a receiving cavity 112 is formed by recessing from the inner surface of the cover plate body 110 toward the outer surface and extends into the protrusion 111.

[0060] It is understandable that the cover plate body 110 is provided with a protrusion 111 to provide sufficient depth for the receiving cavity 112 to accommodate and press the tab 310, thereby helping to optimize the utilization of the internal space of the battery and improve the energy density of the battery.

[0061] It should be noted that in the prior art, the electrode assembly adopts a side-mounted tab method, connecting the tab to the terminal post via a connecting piece. In actual production, to provide connection space for the tab, a certain gap H0 (e.g., 4 mm to 6 mm) is reserved between the inner surface of the cell cover and the lower electrode assembly, thus occupying internal cell space and affecting battery capacity. In contrast, this invention forms an open-end receiving cavity at the protrusion 111 to create a connection channel between the connecting piece 130 and the tab 310. This allows the connection process between the tab 310 and the connecting piece 130 to be carried out within the internal space of the cell cover 100, saving space occupied within the cell, improving internal space utilization, and thus effectively increasing battery capacity.

[0062] In one embodiment of the present invention, such as Figure 2 and Figure 9 As shown, the height of the pole post 120 extending from the outer surface of the cover plate body 110 is lower than the height of the protrusion.

[0063] It is understandable that the pole post 120 is installed through the cover plate body 110. The top height of the pole post 120 extending out of the outer surface of the cover plate body 110 is set to be lower than the height of the protrusion 111, thereby forming an active protection zone composed of the protrusion 111 in the structure, providing effective buffer protection for the pole post 120.

[0064] The cell cover provided in this embodiment of the invention forms an effective physical protection mechanism by providing a protrusion 111 on the outer surface of the cover body 110 and making the top of the terminal post 120 lower than the protrusion 111. When the battery is subjected to external impact or pressure, the protrusion 111 can contact and disperse the external force first, providing buffer protection for the terminal post 120, thereby preventing the impact force from being directly transmitted to the internal electrode assembly 300 of the cell through the terminal post 120, effectively protecting the structural stability of the electrode assembly 300, reducing the risk of misalignment and internal short circuit of the electrode assembly 300 caused by external force, and significantly improving the safety and reliability of the battery.

[0065] In one embodiment of the present invention, multiple battery cells are connected to the upper surface of the terminal post 120 of each cell cover plate 100 via a busbar made of a metal sheet. The height of the protrusion 111 on the outer surface of the cover plate body 110 is slightly higher than the sum of the protrusion height of the terminal post 120 and the thickness of the metal sheet, thereby forming a certain gap between the upper surface of the metal sheet and the upper wall of the battery case. The space reserved in this gap is used to fill or apply thermally conductive structural adhesive to achieve efficient heat conduction and structural fixation.

[0066] Optionally, the height of the pole post 120 extending beyond the outer surface of the cover plate body 110 is H1, and the height of the protrusion 111 is H2, where H1 and H2 satisfy: 1.5 mm ≤ H2 - H1 ≤ 3.0 mm.

[0067] It should be noted that the height difference between H2 and H1 is not less than 1.5mm, ensuring that even if the protrusion 111 is subjected to an impact and undergoes a certain degree of elastic or plastic deformation, there is still sufficient buffer distance to prevent the impacting object from contacting the terminal post 120; the height difference between H2 and H1 is not greater than 3.0mm, avoiding excessive increase in the overall height of the cell due to the excessive height of the protrusion 111, which helps to achieve a compact design, thereby achieving an optimized balance between battery pack space utilization and structural design while ensuring safety.

[0068] In one embodiment of the present invention, the thickness T of the cover plate body 110 is in the range of 1.5 mm ≤ T ≤ 3 mm.

[0069] Understandably, the thickness of the cover body 110, which serves as a platform for supporting components such as the terminal post 120 and the explosion-proof valve, directly affects the overall rigidity and strength of the cell cover 100. Designing the cover body 110 to be 1.5mm to 3mm thick can ensure that the cell cover 100 can withstand the internal pressure of the battery, external impact and assembly stress, while effectively controlling the weight of the parts and material costs, which helps to improve the overall mass energy density of the battery.

[0070] In one embodiment of the present invention, the height of the protrusion 111 is H2, and the thickness of the cover plate body 110 is T, wherein H2 and T satisfy: H2 / T≤3.0.

[0071] Understandably, by limiting the height of the protrusion 111 relative to the thickness of the cover plate body 110, it is possible to effectively prevent the protrusion 111 from shearing or buckling at the root due to an excessively large height-to-width ratio when subjected to lateral or top impacts, thus ensuring the effectiveness of the protrusion 111 as an energy-absorbing structure. Therefore, the ratio between the height of the protrusion 111 and the thickness of the cover plate body 110 is designed to be less than or equal to 3 to ensure the structural stability and strength of the protrusion 111 itself, while also ensuring that the part has good manufacturability and is easy to integrally form through processes such as stamping.

[0072] In one embodiment of the present invention, the wall thickness t of the protrusion 111 is in the range of 1.5 mm ≤ t ≤ 2 mm.

[0073] Understandably, the protrusion 111 is designed with an appropriate wall thickness to ensure that it can absorb a large amount of impact energy through its own plastic deformation when subjected to impact. This prevents it from being too rigid (too large a value for t) and transferring the force to the entire cell cover 100, or from being too thin (too small a value for t) and easily breaking and failing. Therefore, in this embodiment, the wall thickness t of the protrusion 111 is designed to be 1.5 mm ≤ t ≤ 2 mm, achieving the optimal balance between effectively absorbing energy and maintaining structural integrity, thus maximizing its buffering and protective effect.

[0074] In one embodiment of the present invention, the cover plate body 110 is a plain aluminum plate, the material of which is manganese aluminum alloy Al3003, wherein the AL element content is ≥98% and the Mn element content is ≥1%; the tensile strength of the cover plate body σ=145-195Mpa, the yield strength R≥125Mpa, the elongation δ≥3%, and the elastic modulus E=68-70Gpa.

[0075] In one embodiment of the present invention, such as Figure 11 As shown, the cover plate body 110 is elongated, and pole post holes 113 are provided at both ends of the cover plate body 110 along the length direction; correspondingly, there are two pole posts 120, and the two pole posts 120 are respectively provided in the two pole post holes 113; an explosion-proof valve hole 114 is provided in the middle of the cover plate body 110, and the explosion-proof valve hole 114 is used to install an explosion-proof valve; the cover plate body 110 is provided with two protrusions 111, thereby forming two receiving cavities 112 to realize the connection between the two connecting pieces and the corresponding pole ears; the two protrusions 111 are respectively located on both sides of the explosion-proof valve hole, and are located between the explosion-proof valve hole and the pole post hole 113.

[0076] It should be noted that the heat inside the battery cell can be directly conducted outwards not only through the thermally conductive structural adhesive above the terminal post 120, but also through the two protrusions 111, significantly enhancing the heat dissipation effect. Furthermore, the protrusions 111, located between the explosion-proof valve and the terminal post 120, can serve as a thermoelectric separator, improving the battery cell's safety performance.

[0077] It should be noted that in the prior art, the area between the two poles along the length of the cover plate body is not fully utilized. Furthermore, to ensure the welding operation between the tabs and the connecting piece, a certain height must be reserved between the cell cover plate and the lower electrode assembly. Both of these aspects lead to a waste of effective space inside the cell, restricting the increase in battery capacity. Based on this, the present invention arranges two protrusions 111 in the area between the two poles 120, transforming this space into an internal channel for connecting the tabs 310 and the connecting piece 130. This allows the welding process to be completed inside the cell cover plate 100, eliminating the need for a reserved height between the cell cover plate 100 and the electrode assembly 300, significantly improving the space utilization rate inside the cell, thereby effectively increasing the battery capacity within the same volume.

[0078] In this embodiment, an injection hole 115 is provided in the middle of the cover plate body. The injection hole 115 serves as an electrolyte injection channel. After the cell cover plate is sealed, a certain amount of electrolyte is injected into the cell through the injection hole. After the injection is completed, the injection hole is sealed with sealing steel balls and / or sealant to ensure that the inside of the cell is in a completely sealed state.

[0079] Optionally, the projected area of ​​the cover plate body 110 along the thickness direction of the cover plate body is S, the projected area of ​​the protrusion 111 along the thickness direction of the cover plate body is S1, the projected area of ​​the explosion-proof valve hole 114 along the thickness direction of the cover plate body is S2, and the projected area of ​​the pole hole 113 along the thickness direction of the cover plate body is S3. The relationship between S, S1, S2 and S3 satisfies: 0.3≤(2S1+S2+2S3) / S≤0.5.

[0080] It is understandable that by limiting the proportion of the total area of ​​the openings (2S1+S2+2S3) to the total area of ​​the cover plate body 110, it is ensured that while meeting functional requirements, the overall structural strength of the cell cover plate 100 is not excessively weakened, and sufficient load-bearing material is retained to ensure the overall rigidity and sealing reliability of the cover plate.

[0081] For example, the cover plate body 110 is long and narrow, with a length of L and a width of W. The values ​​of L and W are: 145≤L≤320, 22≤W≤86; S1=L×W.

[0082] The cross-section of the protrusion 111 is quadrilateral, with a length of L1 and a width of W1, and S1 = L1 × W1. It should be noted that the protrusion 111 can be a frustum of a cone with its large end connected to the cover plate body 110 and its small end away from the cover plate body 110, and the projected area S1 is the cross-sectional area of ​​the smallest end (small end).

[0083] Optionally, when the battery is impacted in the Z direction (thickness direction of the cover plate body 110), the force acting on the protrusion 111 is F. To ensure sufficient strength for the protrusion 111, the projected area S1 of the protrusion 111 along the thickness direction of the cover plate body satisfies: 1.3F / 2S1 < R; where F is the external impact load in Newtons (N); and S1 is the projected area of ​​a protrusion 111 in square millimeters (mm). 2 R is the yield strength of the cover plate body 110, in megapascals (MPa).

[0084] Understandably, from the perspective of materials mechanics, this provides an engineering design basis for the impact resistance of the protrusion 111. By introducing a safety factor of 1.3, it is ensured that under the action of external impact load F, the stress borne by the two protrusions 111 is much less than the yield strength R of the material, thereby ensuring that the protrusion 111 and the cover plate body 110 can effectively withstand the impact without failure, play a good supporting role, and improve the safety performance of the battery cell.

[0085] Optional, such as Figure 6As shown, the connecting piece 130 includes a first connecting portion 131, a bent portion 132, and a second connecting portion 133 connected in sequence. The first connecting portion 131 is connected to the terminal post 120. The bent portion 132 extends towards the outer surface of the cover plate body 11, so that the second connecting portion 133 is arranged in the receiving cavity 112. The second connecting portion 133 is used to connect with the tab 310. In this way, the second connecting portion 133 is away from the internal space of the battery. The connection process between the tab 310 and the second connecting portion 133 is equivalent to being completed in the internal space of the cell cover plate 100, thereby effectively saving the internal space occupied by the cell and thus increasing the battery capacity.

[0086] For example, the first connecting part 131 and the second connecting part 133 are arranged along the plane of the cover plate body 110.

[0087] It is understandable that the first connecting part 131 extends along the plane direction (horizontal direction) of the cover plate body 110 after being led out from the pole post 120, and the second connecting part 133, after turning through the middle bend 132, also extends along the horizontal direction and into the protrusion 111.

[0088] It should be noted that, as Figure 9 and Figure 10 As shown, the tab 310 is vertically assembled and passes between the side of the second connecting part 133 and the side wall of the receiving cavity 112. The tab area extending above the second connecting part 133 (referred to as the tab connecting part) is bent and attached to the upper surface of the second connecting part 133. The upper surface of the second connecting part 133 and the tab connecting part are welded together, thereby completing the connection between the connecting piece 130 and the tab 310 within the receiving cavity 112.

[0089] In some embodiments of the present invention, to verify the feasibility of the above-mentioned cell cover structure design, multiple cell cover plate samples of embodiments (Examples 1 to 8) and multiple comparative examples (Comparative Examples 1 to 3) were designed. The specific design parameters are shown in Table 1, and the safety of each sample was tested. The total welding area S4 on each connecting piece can be 80 mm². 2 ~400 mm 2 The cross-sectional area S5 of the clamping part can be 120 mm. 2 ~600 mm 2 The height H3 of the clamping part can be 1.2 mm to 3.5 mm.

[0090] Table 1

[0091] Simulation results show that when the conditions 1.2 mm ≤ H3 ≤ 3.5 mm and 0.35 ≤ S4 / S5 ≤ 0.75 are met, the clamping part of Examples 1 to 8 can effectively fix the electrode tab. The clamping part has a certain elasticity and there is no risk of damaging the electrode tab or electrode tab solder joint. The reliability and safety performance of the electrical connection meet the design requirements.

[0092] In contrast, the ratio of areas S4 and S5 in Comparative Example 1 is unreasonable, and the clamping part cannot fix the shape of the electrode tab, posing a risk of inverted insertion; the clamping part in Comparative Example 2 is too small and cannot fix the shape of the electrode tab, posing a risk of inverted insertion; the clamping part in Comparative Example 3 lacks elasticity, posing a risk of damaging the electrode tab and electrode tab solder marks; therefore, when the requirements of 1.2 mm ≤ H3 ≤ 3.5 mm and 0.35 ≤ S4 / S5 ≤ 0.75 are not met, the structural safety requirements are not met.

[0093] A second aspect of the present invention provides a battery, such as Figure 1 and Figure 2 As shown, the battery includes a cell housing, an electrode assembly, and a cell cover plate provided in any of the above embodiments. The cell cover plate and the cell housing form a sealed space. The electrode assembly is disposed in the sealed space and is electrically connected to the cell cover plate.

[0094] It is understood that by employing the cell cover 100 of any of the above embodiments, the battery provided by the present invention possesses the various advantages of the cell cover 100 as described above. Therefore, this battery can limit the position of the tabs, preventing them from shifting within the casing, thereby improving the reliability and safety of the battery's electrical connection; and it has significantly enhanced resistance to external mechanical shocks and compression, effectively preventing internal short circuits caused by external forces, thus greatly improving the battery's safety and reliability. Simultaneously, the space optimization brought about by the cell cover 100 also results in higher energy density, significantly improving overall performance.

[0095] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A battery cell cover plate, characterized in that, include: The cover plate body has a receiving cavity, and the receiving cavity has an opening facing the inner surface of the cover plate body; The pole is inserted into the cover plate body; A connecting piece is disposed on the inner side of the cover plate body. One end of the connecting piece is connected to the pole post, and the other end of the connecting piece extends to the receiving cavity for connection with the electrode tab. The lower molding component includes a lower molding body and a movable component. The lower molding body is disposed on the inner surface of the cover plate body. The movable component is provided with a pressing part. The movable component is movably connected to the lower molding body and is adapted to move between a first position and a second position. In the first position, the movable component presses against the side of the lower molding body away from the cover plate body, and the pressing part extends into the receiving cavity to press the electrode tab into the receiving cavity. In the second position, the pressing part moves out of the receiving cavity.

2. The cell cover plate according to claim 1, characterized in that, The outer surface of the cover plate body is provided with a protrusion, and the receiving cavity is formed by the inner surface of the cover plate body being recessed towards the outer surface and extending into the protrusion.

3. The cell cover plate according to claim 2, characterized in that, The height of the pole extending beyond the outer surface of the cover plate is lower than the height of the protrusion.

4. The cell cover plate according to claim 1, characterized in that, The height of the clamping part in the thickness direction of the lower plastic body is adapted to the difference between the depth of the receiving cavity and the thickness of the connecting piece and the tab.

5. The cell cover plate according to claim 4, characterized in that, The height H3 of the clamping part is in the range of 1.2 mm ≤ H3 ≤ 3.5 mm.

6. The cell cover plate according to claim 1, characterized in that, In the first position, the projection of the welding area between the electrode tab and the connecting piece along the thickness direction of the cover plate body is located within the contour range of the clamping part.

7. The cell cover plate according to any one of claims 1 to 6, characterized in that, The receiving cavity is arranged along the length of the cover plate body and is located in the middle of the cover plate body; There are two pole posts, which are disposed at both ends of the cover plate body along the length direction; There are two connecting pieces. The first end of each connecting piece is connected to one of the two pole posts, and the second end of each connecting piece extends into the receiving cavity to connect to the two pole tabs respectively. There are two movable parts, which are respectively movably connected to both ends of the lower plastic body in the length direction. The pressing part on each movable part is adapted to extend into the receiving cavity to press the two tabs into the receiving cavity respectively.

8. The cell cover plate according to claim 7, characterized in that, The lower molding body is provided with a first positioning part, and the moving part is provided with a second positioning part; At the first position, the first positioning part and the second positioning part abut against each other.

9. The cell cover plate according to claim 7, characterized in that, The connecting piece includes a first connecting part, a bent part, and a second connecting part connected in sequence. The first connecting part is connected to the pole post, the bent part extends toward the outer surface of the cover plate body, and the second connecting part is located in the receiving cavity.

10. A battery, characterized in that, include: Battery cell casing; And the cell cover plate as described in any one of claims 1 to 9, wherein the cell cover plate and the cell housing form a sealed space; The electrode assembly is located in the sealed space and is electrically connected to the cell cover plate.

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